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Planning implications of composting toilets Grant, Brian David 1977

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1.1 PLANNING IMPLICATIONS OF COMPOSTING TOILETS by BRIAN DAVID GRANT B.E., U n i v e r s i t y of Saskatchewan, 1968 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n THE FACULTY OF GRADUATE STUDIES (School of Community and Regional Planning) We accept t h i s t h e s i s as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA May, 1977 Brian David Grant, 1977 In presenting t h i s thesis i n p a r t i a l fulfilment of the requirements for an advanced degree at the University of B r i t i s h Colimbia. I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the Head of my Department or by h i s representatives. I t i s under stood that copying or publication of t h i s thesis f o r f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of School of Community and Regional Planning The University of B r i t i s h Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1W5 Date May 4, 1977 i i ABSTRACT The composting t o i l e t i s one response to the problems that are incr e a s i n g l y being associated with modern systems of sewage d i s p o s a l ; these problems include high f i n a n c i a l cost, accelerated eutrophication of water bodies and the waste of valuable nutrients i n human excreta. The l a s t problem makes these systems p a r t i c u l a r l y inappropriate f or use i n a Conserver Society, a major p r i n c i p l e of which i s the r e c y c l i n g of p h y s i c a l materials. The purpose of t h i s thesis i s therefore to evaluate the s u i t a b i l -i t y of the composting t o i l e t as a sewage system, to determine whether or not i t i s a f e a s i b l e a l t e r n a t i v e to e x i s t i n g sewage systems and to explore the planning implications of i n s t a l l i n g composting t o i l e t s i n e n t i r e communities as well as i n i n d i v i d u a l dwellings. The theory and operation of a composting t o i l e t i s explained i n conceptual terms and the two basic types of composting t o i l e t s are described and evaluated. Four makes of t o i l e t are described i n greater d e t a i l i n an appendix. The treatment of greywater i s recognized as a key component of the t o t a l system. The e s s e n t i a l d i f f e r e n c e s between greywater and combined wastewater are discussed, p a r t i c u l a r l y as they are rel a t e d to treatment requirements, and appropriate methods of treatment, e x i s t i n g and proposed, are presented. Following a review of the regulatory status of the t o i l e t s , and of the kinds of uses for which they have already been i n s t a l l e d , the t o t a l system i s evaluated as a sewage system i n terms of the needs both of today's society and those of a Conserver Society. The a n a l y t i c a l portion of the thesis seeks to determine the f e a s i b i l -i t y of the composting t o i l e t system. The method i s a comparative analysis between composting t o i l e t s and several sewage systems, i n c l u d i n g package i i i treatment plants, septic tanks and gravity and vacuum sewers, i n the context of two r e s i d e n t i a l areas i n the M u n i c i p a l i t y of Surrey, B r i t i s h Columbia. The analysis i s both q u a l i t a t i v e , i n terms of e f f e c t s on land use and b i o p h y s i c a l systems, and q u a n t i t a t i v e , i n terms of monetary and energy costs. The thesis concludes that the composting t o i l e t i s indeed a d e s i r a b l e system for the disposal/treatment of human body 'wastes'. It meets or surpasses the requirements expected of any sewage system, and i s s u i t a b l e for use i n a Conserver Society as w e l l . A composting t o i l e t system i s a f e a s i b l e a l t e r n a t i v e to the proposed sewage systems i n each of the compar-ison areas, and i n f a c t costs l e s s money to i n s t a l l and maintain and requires l e s s damage or d i s r u p t i o n to environmental systems. F i n a l l y , i n a d d i t i o n to f i n a n c i a l savings, the use of t h i s system w i l l have important implications for planners and communities, e s p e c i a l l y the increased f l e x i b i l i t y i t provides i n the l o c a t i o n , design, construction and financ-ing of r e s i d e n t i a l subdivisions or s i n g l e dwellings. The composting t o i l e t system i s not only appropriate for use i n numerous i n d i v i d u a l s i t u a t i o n s , but i t should be s e r i o u s l y considered by most low to medium density communities which need to upgrade or i n s t a l l a sewage system. i v TABLE OF CONTENTS CHAPTER I INTRODUCTION page A. THE NATURE OF THE PROBLEM . . . . ' 1 B. OBJECTIVES ' . . 6 C. SCOPE . . . 6 CHAPTER I I THE COMPOSTING TOILET SEWAGE SYSTEM A. INTRODUCTION 8 B. COMPOSTING TOILET SUB-SYSTEM 8 1. Introduction 8 2. O r i g i n and Development . 8 3. P r i n c i p l e of Operation . . 9 4. Operation and System Management 10 (a) P h y s i c a l requirements 10 (b) What goes in/What comes out . . . . . . . . 11 (c) I n s t a l l a t i o n and operation requirements . . . 12 (d) Nuisance factors 14 5. D e s c r i p t i o n and Evaluation of Composting To i l e t - Types 16 6. Development of the Composting T o i l e t Concept 20 C. THE GREYWATER SUB-SYSTEM 1. Introduction . 21 2. The Nature of Greywater . . . . . . . . . . . . 21 3. The Treatment of Greywater . 26 4. Conclusion 29 D. REGULATORY STATUS OF COMPOSTING TOILETS . . . . . . 30 • E. EXISTING INSTALLATIONS . . . . . . . 31 F. IS THE COMPOSTING TOILET SYSTEM A SUITABLE SEWAGE SYSTEM? 33 G. CONCLUSION . 36 CHAPTER I I I COMPARATIVE ANALYSIS OF SEWAGE SYSTEM ALTERNATIVES A. INTRODUCTION . . . 37 1. Methodology 37 B. DESCRIPTION OF STUDY AREAS 1. Bridgeview (a) H i s t o r i c a l and p h y s i c a l d e s c r i p t i o n . . . . 40 (b) The proposed sewage system 42 2. Panorama Ridge West (a) Physical d e s c r i p t i o n 43 (b) The proposed sewage system 45 C. THE COMPARISON 1. Bridgeview (a) D e s c r i p t i o n of systems 46 (b) E f f e c t s on land use and b i o p h y s i c a l systems 48 (c) Monetary and energy costs .51 (d) Summary an a l y s i s 56 2. Panorama Ridge West (a) D e s c r i p t i o n of systems . . 57 (b) E f f e c t s on land use and b i o p h y s i c a l systems 58 v i (c) Monetary and energy costs . 60 (d) Summary ana l y s i s 66 D. CONCLUSION . 6 9 CHAPTER IV PLANNING IMPLICATIONS A. INTRODUCTION 70 B. THE IMPLICATIONS 1. Land Use 71 2. Cost 73 3. F l e x i b i l i t y 76 C. POTENTIAL APPLICATIONS OF THE COMPOSTING TOILET SYSTEM 81 CHAPTER V CONCLUSION AND RECOMMENDATIONS A. SUMMARY CONCLUSIONS 85 B. RECOMMENDATIONS . 90 LIST OF REFERENCES 92 APPENDICES A. DESCRIPTION AND EVALUATION OF FOUR COMPOSTING TOILETS . 96 B. CHEMICAL AND BIOLOGICAL ANALYSES OF COMPOSTING TOILET END PRODUCT 118 C. OWNER-BUILT COMPOSTING TOILETS/PRIVIES 126 D. GREYWATER PRE-TREATMENT FILTER 130 E. REGULATORY GUIDELINES FOR COMPOSTING TOILETS . . . . . . . . 133 F. SEWAGE SYSTEM COSTS—ASSUMPTIONS AND CALCULATIONS . . . . . . 141 v i i LIST OF TABLES Page I. P o l l u t i o n Loads of Wastewater Sampled from Plumbing Fixtures 23 I I . Comparison Between Quantities of P o l l u t i o n Per Day i n Greywater and Blackwater 23 I I I . Percent of T o t a l Water Use of Each Plumbing Fixture . . . . . . 28 IV. Monetary Costs of Vacuum Sewer System - Bridgeview 51 V. Unit Cost of Composting T o i l e t s - Bridgeview . . . 53 VI. Unit Cost of Package Treatment - Bridgeview 5A VII. T o t a l and Unit Costs of A l t e r n a t i v e Sewage Systems -Bridgeview . 57 VIII. Unit Cost of Package Treatment - Panorama Ridge West .60 IX. Sanitary Sewer Costs - Panorama Ridge West 64 X. Unit Costs of Composting T o i l e t s - Panorama Ridge West 65 XI. T o t a l and Unit Costs of A l t e r n a t i v e Sewage Systems -Panorama Ridge West 67 v i i i LIST OF ILLUSTRATIONS MAPS Page 1. M u n i c i p a l i t y of Surrey 38 2. Bridgeview 41 3. Panorama Ridge West . . 44 FIGURES Page 1. Vacuum Sewer System - T y p i c a l I n s t a l l a t i o n Pattern 47 2. Subdivision Plan and Sewer Design - Panorama Ridge West . . . . . 62 3. A l t e r n a t i v e Subdivision Design: Two-Acre, Five-Unit Cluster . . . 63 i x ACKNOWLEDGEMENT Perhaps more than most, t h i s thesis must acknowledge the assistance of many people. There i s not a great deal of published information oh the to p i c of composting t o i l e t s , and a glance at the L i s t of References w i l l q u i c k l y r e v e a l the many entries shown as "Personal Communications". To a l l these people I am thankful - many small but v i t a l pieces of informa-t i o n became a v a i l a b l e when needed. I wish p a r t i c u l a r l y to thank the following: Surrey Planning and Engineering Departments, Northern P u r i f i c a t i o n Services, Michael S l a t e r of A p l i n and Martin, C i v i l Mechanical Consulting Engineering , Jim Wright of Vacusan Systems Ltd. and John Huber of ATCO Leasing. F i n a l l y , I am e s p e c i a l l y g r a t e f u l f o r the complementary r o l e s played by my two advisors, Professors Fox and Oldham. I was always aware not only that I must be c a r e f u l i n how I presented my arguments f o r and against various sewage systems, but also that I could count on t h e i r support f o r my basic approach. I picked a rather unusual thesis t o p i c , and I consider myself fortunate to have worked with persons who shared my enthusiasm f o r the subject r i g h t from the s t a r t . CHAPTER I INTRODUCTION I.A THE NATURE OF THE PROBLEM Perhaps the most important r e a l i z a t i o n to emerge as a r e s u l t of the a t t e n t i o n given to environmental issues i s that the world i s f i n i t e and cannot support continuous growth. Yet i n modern s o c i e t i e s , more and more mat e r i a l and energy resources are consumed each year i n the e f f o r t to sustain economic growth. To resolve t h i s c o n f l i c t , and to evolve human systems which are sustainable and i n harmony with t h e i r b i o p h y s i c a l support systems, an increasing number of Canadians are advocating the concept of the Conserver Society. The Science Council of Canada, i n i t s Conserver  Society Notes, o p e r a t i o n a l l y defines a Conserver Society as one which: (1) promotes economy of design of a l l systems—"doing more with l e s s " ; (2) favours reuse or r e c y c l i n g and, wherever po s s i b l e , reduction at source (3) questions the ever-growing per capita demand for consumer goods, a r t i f i c i a l l y encouraged by modern marketing techniques; and (4) recognizes that a d i v e r s i t y of solutions i n many systems, such as energy and transpor-t a t i o n , might i n e f f e c t increase tha-V o v e r a l l economy, s t a b i l i t y and r e s i l i e n c e . I f we accept both the need for a Conserver Society and t h i s statement of i t s p r i n c i p l e s , then we accept the r e s p o n s i b i l i t y of f i r s t ensuring that our personal l i f e - s t y l e i s i n accordance with those p r i n c i p l e s . The next step i s to examine the s o c i a l and economic i n s t i t u t i o n s i n which we are involved and, where necessary, to explore ways of r e s t r u c t u r i n g them to be compatible with a Conserver Society. This i s e s p e c i a l l y important for planners, who may exert s t r a t e g i c influence on those i n s t i t u t i o n s , and i s the underlying purpose of t h i s t h e s i s . One s o c i e t a l i n s t i t u t i o n thus i n great need of c r i t i c a l evaluation 2 i s our modern system of water-borne sewage d i s p o s a l . We use large q u a n t i t i e s of potable water to transport human body wastes away from t h e i r point of o r i g i n , and then spend huge amounts of money ( i n those communities that can a f f o r d i t ) i n attempts to restore the water to i t s o r i g i n a l q u a l i t y , but without much success. I t i s becoming inc r e a s i n g l y obvious, i n terms of money and water, that we cannot a f f o r d such a system much longer. Following Harold Leich[34][35], some common adverse e f f e c t s of present sewage d i s p o s a l systems include: (1) Waste of large quantities of organic and inorganic n u t r i e n t s , which contribute to accelerated eutrophication of downstream water bodies; the l o s s of these nutrients requires the heavy use of chemical f e r t i l i z e r s at high environmental and economic cost. (2) Use of large quantities of potable water to carry away small quan-t i t i e s of body wastes. The t y p i c a l user of a f l u s h t o i l e t contam-inates 59,100 l i t r e s of fresh water per year to carry away 750 l i t r e s of body waste. (3) Risk of transmitting diseases to downstream water users, the extent of which Is i n v e r s e l y proportional to the c o s t / e f f i c i e n c y of the treatment process. An a d d i t i o n a l p o s s i b i l i t y i s the cr e a t i o n of carcino-genic substances by the treatment i t s e l f . (4) Enormous and increasing economic cost of providing sewer l i n e s , treatment plants and sludge d i s p o s a l . Energy costs are becoming s i g n i f i c a n t as w e l l . (5) Concentration of large amounts of human wastes at c e n t r a l i z e d treatment f a c i l i t i e s which are vulnerable to power f a i l u r e s , equip-ment breakdowns, employee s t r i k e s and by-passing during f l o o d i n g or high water, any of which can r e s u l t i n the discharge of raw sewage into water. The use of a se p t i c tank/leach f i e l d system a l l e v i a t e s or avoids some but not a l l of these problems. If properly designed, i n s t a l l e d and maintained, t h i s system does not give r i s e to the l a s t two problems at a l l and minimizes the r i s k of disease transmission. However, the absence of one or a l l of the above conditions i s a l l too common; the r e s u l t i n g malfunctions range from groundwater contamination to back-up of sewage into the home. Sub-surface conditions often p r o h i b i t the use of leach f i e l d s e n t i r e l y , and the presence of a f l u c t u a t i n g water table or an impermeable layer i s not even taken i n t o account by the standard p e r c o l a t i o n t e s t [ 4 1 ] , on which most "proper design" i s based. F i n a l l y , the economic cost i s not l i m i t e d to the i n i t i a l i n s t a l l e d p r i c e . Plugged drain t i l e s require expensive t r e a t -ments and even i n a p e r f e c t l y operating system, the necessary pumping out of the se p t i c tank represents a s i g n i f i c a n t r e c u r r i n g cost. This i s the present s i t u a t i o n , serious enough, but projections f o r the future include quadrupling of municipal sewage loads within f i f t y years [34]. Aside from the environmental impact of disposing of t h i s e f f l u e n t , there, w i l l be the in c r e a s i n g l y c r i t i c a l problem i n some areas of f i n d i n g s u f f i c i e n t water, of whatever q u a l i t y , to transport the sewage. Water-borne waste c o l l e c t i o n and c e n t r a l i z e d disposal was a mid-nineteenth cen-tury s o l u t i o n to a serious problem of human hygiene[51]. This 'solution', however, i s no longer adequate i n the face of the magnitude of today's problems. The key to human waste dis p o s a l i n a Conserver Society i s the second element of the operational d e f i n i t i o n — r e c y c l i n g . In e c o l o g i c a l systems, matter i s i n constant c i r c u l a t i o n . Organic material i n the form of plants, animals and t h e i r excreta i s broken down by decomposer organisms i n the s o i l into substances which can then be taken up again by plants. Modern human systems have broken t h i s cycle and replaced i t with two l i n e a r processes. The f i r s t c a r r i e s organic matter and chemical elements from the s o i l to humans i n the form of food, then disposes of the unused p o r t i o n (garbage) and the u n a s s i l i l a t e d p ortion (excreta) anywhere but at the point of o r i g i n — as l a n d f i l l , causing s o i l p o l l u t i o n ; In water bodies, causing water p o l l u t i o n ; and even by burning, causing a i r p o l l u t i o n [ 2 5 ] . The second process naintalns s o i l f e r t i l i t y by replacing the nutrients extracted from the s o i l i n the form of crops with chemical f e r t i l i z e r s manufactured from petroleum products and mineral rocks. In a Conserver Society, the valuable nutrients i n sewage and garbage would be returned to the s o i l i n order to produce more food, thus c l o s i n g the cycle and reducing the need to use non-renewable resources i n the manufacture of f e r t i l i z e r . As a renewable resource, human body waste i n i t s p o t e n t i a l as f e r t i l -i z e r shares with other renewable resources the necessity of being concen-trated before the most e f f e c t i v e use can be made of i t . Thus the i d e a l system appears to be community-scale c o l l e c t i o n and processing plants, with subsequent t r a n s f e r of the f e r t i l i z e r to surrounding farms or market gardens. It can be argued here that sanitary sewer systems already concentrate sewage at treatment plants and that only the treatment process need be im-proved, with the r e s u l t i n g sludge composted and sold to farmers rather than used as l a n d f i l l or burned. This jis_ a benefit of sewer systems and must be taken advantage of i n communities which are already served by sewers and committed to further expenditures f o r improved e f f l u e n t treatment. There are two serious problems, however, with t h i s attempt to convert e x i s t i n g sanitary sewers and treatment plants into environmentally-appropriate sewage systems. The f i r s t i s the presence i n urban sewage sludge of to x i c substances such as heavy metals[3.1]. The Westwater Research Centre has recently documented i t s concern over the ease with which these materials can enter the storm and sanitary sewers in the Lower Mainland of British C6lumbia[14]. There i s also doubt about the a b i l i t y of current sewage treatment techniques to completely eliminate viruses as well as bacteria[34]. The second problem, of course, is the waste of large quan-t i t i e s of fresh water. The most elegant solution to the problem of toxic substances, and the one suggested by Westwater, i s to prevent their entry into sewer sys-tems i n the f i r s t place. As for the problem of water waste, part of the solution i s to reduce the amount of water used, which would also increase the concentration of the sewage and permit the use of physical reclamation systems such as vacuum evaporators[22]. Another part of the solution involves recycling the water which is_ used; for example, the effluent from an upstream community's treatment plant i s suitable for use in a downstream community's flush t o i l e t s . These solutions, especially the last one, are conceptually simple but may be technologically complex. They do i l l u s t r a t e that in communities where i t is necessary to make use of existing sewer systems, this can. be achieved in accordance with Conserver Society principles. Nevertheless, there are many situations where conventional sewage systems and/or the modifications suggested above, are too expensive. It i s in these situations where there is a need for alternative systems, of which the composting t o i l e t i s one example. That they are only one example i s important; this thesis does not propose the composting t o i l e t system as a panacea. It rather views i t as representing a class of on-site sewage sys-tems which are simple in design, operation and maintenance; inexpensive; use l i t t l e or no water and energy; do not pollute the environment; and recycle the nutrients in human excreta back to the s o i l . Although this solution to the problem/opportunity of waste disposal flows out of the second characteristic of a Conserver Society, i t is well to remember the fourth characteristic—that a diversity of solutions will best achieve overall economy, stability and resilience in our total sewage system. I.B OBJECTIVES Inasmuch as composting toilets are s t i l l relatively unknown on this continent, the first objective is to describe the composting toilet system and evaluate its capability and suitability as a sewage system; i.e., can it effectively do what sewage systems ought to do and must do? The second objective is to determine whether or not the composting toilet system is a feasible alternative to conventional systems like sanitary sewers and septic tanks. The third objective is to identify and explore the planning impli-cations of using composting toilets and to suggest situations in which they can best be used. A final objective is to accomplish the first three in a simple, straightforward manner that will be useful to any individual who plans. I.C SCOPE The remainder of the thesis is divided into four chapters, approx-imately based on the above objectives. Chapter II seeks to explain the composting toilet system in theory and practice. The principle of operation and performance characteristics of the toilet itself are described, followed by an evaluation of the two basic types of toilet. The nature and treatment of greywater is examined in light of the importance of the greywater sub-system within the total sys-tem. The chapter then describes the regulatory status of composting toilets, 7 provides a b r i e f overview of e x i s t i n g i n s t a l l a t i o n s and concludes with an evaluation of the s u i t a b i l i t y of the composting t o i l e t system as a sewage system. Chapter I I I compares composting t o i l e t systems to more or l e s s conventional systems i n two r e s i d e n t i a l areas i n B r i t i s h Columbia's Lower Mainland. The comparison i s i n terms of cost and e f f e c t s on land use and b i o p h y s i c a l systems. Chapter IV discusses the planning implications of using composting t o i l e t systems as a sewage system f o r communities as w e l l as f o r i n d i v i d u a l households, and explores p o t e n t i a l a p p l i c a t i o n s of the system. Chapter V contains summary conclusions and several recommendations. In a f i n a l evaluation of the composting t o i l e t system, the chapter seeks to put t h i s system i n the context of the t o t a l s o l u t i o n to the current problem of human waste d i s p o s a l . 8 CHAPTER I I THE COMPOSTING TOILET SEWAGE SYSTEM II.A INTRODUCTION The general purpose of t h i s chapter i s to evaluate the composting • t o i l e t as a sewage system. The t o t a l system i s composed of two sub-systems: the d i s p o s a l and treatment of human body wastes, i n v o l v i n g the composting t o i l e t i t s e l f ; and the disp o s a l and treatment of greywater, the e f f l u e n t from other household plumbing f i x t u r e s . Each of the two sub-systems w i l l be described i n turn, followed by a discussion of the regulatory status and e x i s t i n g i n s t a l l a t i o n s of the t o t a l system. The chapter w i l l conclude with an evaluation, according to f i v e c r i t e r i a , of the s u i t a b i l i t y of the composting t o i l e t system. II.B THE COMPOSTING TOILET SUB-SYSTEM B. l Introduction The composting t o i l e t represents a r a d i c a l change i n the di s p o s a l and treatment of human excreta. A major d i f f e r e n c e , of course, i s that i t does not use water as a transport medium. Even more s i g n i f i c a n t , from the stand-point of acceptance by a society that views human excreta as " d i r t y " or d i s t a s t e f u l , and therefore to be gotten r i d of as quickly as possible,, t h i s material can no longer be simply flushed s a f e l y out of sight and mind with a f l i p of the w r i s t . Instead i t must be retained w i t h i n the household f o r time periods of up to several years. Under the circumstances, a c e r t a i n amount of apprehension i s understandable. The p a r t i c u l a r purpose of t h i s chapter, therefore, i s to explain how the composting t o i l e t works. B.2 Or i g i n and Development The f i r s t composting t o i l e t was b u i l t i n Sweden i n 1939 for priv a t e use by i t s inventor, Rikard Lindstrom. I t was not developed f u r t h e r , however, u n t i l awakening environmental consciousness i n Sweden i n the m i d - s i x t i e s r e s u l t e d i n v i r t u a l p r o h i b i t i o n of s e p t i c tanks i n r u r a l and r e c r e a t i o n a l areas. A f t e r a s e r i e s of prototypes eliminated e a r l y problems, the t o i l e t began commercial.production i n Sweden i n 1964 under the name, Clivus-Multrum (pronounced cleav-us; l i t . , i n c l i n e d mouldering room). Since 1974, the t o i l e t has been i n production i n the United States as w e l l by C l i v u s -Multrum USA, Inc., who are also the Canadian d i s t r i b u t o r . A number of other t o i l e t s have.also appeared on the market, i n attempts to improve on the design of the C l i v u s . B.3 P r i n c i p l e of Operation The term "composting t o i l e t " i s used i n t h i s t h e s i s l a r g e l y f o r ease of convenience; i t a c t u a l l y includes two b i o l o g i c a l processes. The f i r s t i s mouldering, "a slow process of b i o l o g i c a l combustion during which organic matter i s converted to a st a b l e , humus-like substance through the a c t i o n of various microorganisms under aerobic conditions"[37]. The second i s composting, the same process except that i t occurs much f a s t e r ; the heat generated by the decomposition i s retained within a r e l a t i v e l y small, enclosed area, as i n a garden compost p i l e , rather than d i s s i p a t e d as i n mouldering. Mouldering i s the process which occurs i n the C l i v u s , while composting i s the process which occurs i n most of i t s competitors. This and other differences between the two types of t o i l e t w i l l be explored l a t e r i n t h i s s e c t i o n . Meanwhile, the following d e s c r i p t i o n of what happens i n a 'composting' t o i l e t i s generally a p p l i c a b l e to both types. The composting t o i l e t reproduces as nearly as p o s s i b l e the decompos-• f . i t i o n process found i n natural systems. Organic matter drops into an impervious container, the bottom of which i s covered with a " s t a r t e r bed", 10 a layer of s o i l with materials such as grass, leaves and peat moss. This bed contains a population of s o i l microorganisms which begin working on the organic matter as soon as i t lands. Urine i s absorbed i n the lower la y e r s , where i t s ammonia i s decomposed to carbon dioxide and n i t r a t e s by various n i t r o - b a c t e r i a , including nitrosomonas. As the urine drains from the s o l i d m a t e r i a l , other aerobic organisms degrade the carbonaceous organics present i n feces. This decomposition of feces occurs i n two stages: a rapid f i r s t stage i n which larger p a r t i c l e s are broken down and heat i s produced, and a much slower stage during which organic-bound substances are converted (mineralized) i n t o inorganic nutrients that are s u i t a b l e f o r d i r e c t uptake by pl a n t s [ 3 7 ] . Gaseous products of decomposition, carbon dioxide and water vapour, escape through a pipe which vents on the roof. Once the process i s begun i t i s continuous, although the l e v e l of m i c r o b i a l a c t i v i t y may vary g r e a t l y with the ambient temperature. The f i n i s h e d compost i s removed from the lower p o r t i o n of the container, with the residence time i n the chamber depending on the type of t o i l e t . B.4. Operation and System Management (a) P h y s i c a l requirements A properly operating composting t o i l e t , with i t s dense and diverse population of microorganisms, i s a small, s e l f - s u s t a i n i n g ecosystem i n which constant and e f f i c i e n t decomposition i s governed by the following p h y s i c a l f a c t o r s [ l ] [ 1 8 ] [ 3 7 ] : Oxygen supply. There must be a good supply of oxygen to maintain aerobic decomposition. Oxygen i s brought into the chamber through a i r intakes and material entrance ports, whiie aeration of the p i l e i t s e l f i s u s u a l l y promoted by ducts which pass through the material. Oxygen supply i s i n h i b i t e d by compaction or compression of the material or by excess 11 f l u i d content. Nutrient supply. E f f e c t i v e decomposition of the nitrogen compounds i n organic matter depends on the presence of s u f f i c i e n t carbon, which i s necessary to the microorganisms that are important i n the i n i t i a l breakdown period. In e f f e c t , the balance between carbon and nitrogen a f f e c t s the r a t e of decomposition and thus determines the r e t e n t i o n time of m a t e r i a l i n the chamber. The optimum carbon-nitrogen r a t i o (C/N) i s about 30. Temperature• The main e f f e c t of temperature i s i n regulating the rate of decomposition. The a c t i v i t y w i l l decrease markedly when the temperature drops below about 18°C and the microorganisms may become dormant u n t i l the temperature r i s e s again. The temperature i n the chamber i s also important i n promoting evaporation of l i q u i d s and re g u l a t i n g the humidity of the c i r c u l a t e d a i r . Temperature v a r i e s d i r e c t l y as a r e s u l t of heating the chamber, and i n d i r e c t l y as a r e s u l t of adding materials l i k e paper which l i b e r a t e considerable amounts of heat when decomposing. pH f a c t o r . The a c t i v i t y both of the decomposing b a c t e r i a and of the enzymes on which they depend requires that the m a t e r i a l be a l k a l i n e ( i e , a pH greater than 7.0). This i s normally not a problem as urine i s a l k a l i n e , but a d d i t i o n of water, ei t h e r a c c i d e n t a l l y or to improve moisture content, increases the danger of a c i d i t y . (b) What goes in/what comes out Materials that can be put into the chamber include: urine; excrement; t o i l e t paper(some kinds decompose more e a s i l y than others); tampax and kotex; grease and f a t ; dust; vegetable, f r u i t and meat scraps; bones (some lar g e r bones may not completely decompose); and eggshells. The amounts of these various materials which can be added depends on the p a r t i c u l a r make of t o i l e t . 12 Materials which must be excluded are p a i n t s , t o x i c l i q u i d s , chemicals, p e s t i c i d e s and e s p e c i a l l y sanitary agents. Metals should not be put i n since the humic acids produced i n the chamber are strong enough to d i s s o l v e some elements, p a r t i c u l a r l y lead[26]. Materials such as glass, p l a s t i c and heavy or coated paper w i l l simply add unnecessary bulk and should be excluded. As f o r what comes out, when the t o i l e t i s i n s t a l l e d and operating c o r r e c t l y , the end product i s a dark, r i c h humus with an earthy odour. Because of evaporation of l i q u i d s and decomposition of s o l i d s , the volume i s reduced by up to 90%, and a f t e r an i n i t i a l one or two year delay, the t o i l e t produces humus at the approximate rate of 45 l i t r e s per person per year. This material i s a high-quality s o i l amendment — one source gives the approximate nutrient r a t i n g as 20% nitrogen (N): 12% phosphorus (P); 14% potassium (K)[18]. More importantly, a l l sources agree that the end product i s v i r t u a l l y pathogen-free[18][37][43]. The s a n i t a t i o n of the excreta i s accomplished p a r t l y by the heat generated during i n i t i a l decomposition, p a r t l y by micro-organisms i n the chamber which attack pathogens and p a r t l y by the i n h o s p i t -able h a b i t a t . For instance, the r e l a t i v e l y dry conditions are not conducive to v i r u s e s such as those causing hepatitus, which are k i l l e d more r a p i d l y than i n sewage treatment plants[18]. A v a i l a b l e r e s u l t s from nutrient and b a c t e r i o l o g i c a l analyses are presented as Appendix B. (c) I n s t a l l a t i o n and operation requirements Proper i n s t a l l a t i o n of composting t o i l e t s i s very important to t h e i r subsequent e f f e c t i v e operation. P a r t i c u l a r a t t e n t i o n must be given to the v e n t i l a t i o n stack and to the s t a r t e r bed. The v e n t i l a t i o n stack i s the means by which gaseous materials are 13 removed from the chamber. Acting j u s t l i k e a chimney, the stack creates a d r a f t , aided by convection currents generated i n the chamber by the r i s i n g heat of decomposition, which draws a i r into the chamber and c a r r i e s i t and other gases up to the vent. The stack must be high enough to create s u f f i c -i e n t suction; i t must not have bends greater than 45°; and i t must be kept warm where i t passes through unheated spaces so that water vapour does not condense and run back into the chamber to cause excess moisture conditions. Some t o i l e t s are equipped with a fan to supplement natural d r a f t ; i f n a t u r a l d r a f t i s not s u f f i c i e n t i n others, a small fan may have to be added. In any case, the room occupied by the t o i l e t should be exhausted through the t o i l e t i n order to maintain the proper d i r e c t i o n of a i r flow. The s t a r t e r bed has two important functions. It i s the i n i t i a l source of the decomposing microorganisms and thus must include good garden s o i l or compost. I t a l s o provides a buffer to absorb urine i n the e a r l y months of operation u n t i l the mass i n the t o i l e t has accumulated to the point where i t can take over t h i s function. Composting t o i l e t s , some more than others, are most s e n s i t i v e to urine overloading i n t h i s i n i t i a l period, and making sure that the s t a r t e r bed i s t h i c k and absorbent enough and i n the r i g h t places w i l l avoid l a t e r problems r e l a t e d to urine accumulation. Operating requirements vary i n number and importance according to type and make of t o i l e t , but there are a few simple management techniques that w i l l encourage e f f i c i e n t and trouble-free decomposition. Probably the most important of these i s the d e l i b e r a t e a d d i t i o n of c e r t a i n materials. I t was stated e a r l i e r that the optimum C/N i s about 30; human excreta are r e l a t i v e l y low i n carbon, however, arid carbonaceous materials such as kitchen scraps, peat moss, sawdust and/or grass c l i p p i n g s should be added p e r i o d i c a l l y to the chamber, or i n response to changes i n 14 the loading of the t o i l e t . This f a c i l i t a t e s decomposition both by improving the C/N and by promoting aeration through absorption of l i q u i d s . I t also aids s a n i t a t i o n of the b a c t e r i a since the c e l l u l o s e present i n organic materials i s necessary f o r the s u r v i v a l of some of the microorganisms which destroy disease-producing b a c t e r i a and viruses[18]; some of these micro-organisms enter with the organic matter i t s e l f [ 1 ] . Because of the systemic nature of the t o i l e t ' s operation, t h i s prac-t i c e w i l l a lso have an e f f e c t on the re g u l a t i o n of the other p h y s i c a l f a c t o r s . For example, adding paper or other c e l l u l o s i c materials w i l l r e s u l t i n increased generation of heat, thus r a i s i n g the p i l e temperature, and increased rate of evaporation, thus changing the moisture content of the p i l e . Since temperature regulation i s c r i t i c a l at low ambient temperatures, i t may be necessary to take a d d i t i o n a l steps to regulate the temperature, e s p e c i a l l y when the t o i l e t i s to be used year round i n temperate or cold climates. Some t o i l e t s come with a heating element; i n others, extra i n s u l -a t i o n w i l l help, as w i l l ensuring that the a i r drawn into the t o i l e t i s pre-heated, perhaps by the household heating system. The only other management a c t i v i t y common to a l l t o i l e t s i s the pe r i o d i c removal of the end product, taking care only to wait u n t i l the mass i n the chamber i s s u f f i c i e n t l y great before removing the f i r s t batch. The s t a r t e r bed constantly renews i t s e l f and should not be removed or other-wise disturbed a f t e r i t i s put i n place. (d) Nuisance f a c t o r s There are only two nuisance factors — odour and i n s e c t s . Their con-t r o l i s part of normal management p r a c t i c e s , but since they are perhaps the most commonly expressed concerns about the composting t o i l e t , they are 15 treated separately i n t h i s section. Given proper i n s t a l l a t i o n and management, composting t o i l e t s should not smell. These conditions are not always met, and the r e s u l t s are described i n a l a t e r s e ction and i n Appendix A; however, the design of most t o i l e t s i s such that odour i s s l i g h t or non-existent. In the f i r s t place, there i s or should be no odour from the decomposition i t s e l f . The smells associated with the well-known p i t p r i v y are l a r g e l y due to the anaerobic,decomposition which takes place when urine cannot escape from the p i t . Matter i n compost-t i n g t o i l e t s i s decomposed a e r o b i c a l l y ; the only source of odour, then, i s the f r e s h l y deposited feces and urine. When the t o i l e t seat i s r a i s e d , the p a r t i a l vacuum created i n the chamber by the v e n t i l a t i o n stack (and/or fan) sucks a i r i n through the opening and prevents odours from escaping. Odours are vented along with carbon dioxide and water vapour through the roof vent. Odour i s only a serious problem when excess moisture i n the chamber forces the change from aerobic to anaerobic decomposition. This can be avoided, as noted e a r l i e r , by not overloading the t o i l e t with l i q u i d s , e s p e c i a l l y urine; by ensuring proper v e n t i l a t i o n and evaporation of l i q u i d s ; and by providing enough absobent materials as a b u f f e r , e s p e c i a l l y i n the i n i t i a l period. The problem of i n s e c t i n f e s t a t i o n i s more nearly unavoidable, but the magnitude of the problem can be c o n t r o l l e d . The entrance of f l i e s through vents can be prevented by appropriate screening, but there i s always the p o s s i b i l i t y that kitchen scraps w i l l contain insect eggs or larvae that become insect s i n the chamber. This r i s k can be minimized by not allowing food scraps to s i t uncovered during f l y season. Moreover, i f the f l i e s can be kept i n s i d e the chamber, there i s e f f e c t i v e l y no problem; i n most cases, f l i e s w i l l be prevented from entering the room by the negative pressure d i f f e r e n t i a l between the chamber and the room. In serious cases, a fan may need to be added to increase the pressure b a r r i e r , or a mild i n s e c t i c i d e 16 might be used j u s t under the t o i l e t seat ot kitchen receptacle, without harming the b e n e f i c i a l organisms i n the p i l e below. F l i e s seem to be a problem with most t o i l e t s , but p r i m a r i l y i n the f i r s t few weeks or months of operation, and a d d i t i o n of sawdust helps at t h i s point[50]. Eventually, time w i l l create a b i o l o g i c a l balance which w i l l prevent freak population explosions[18]. B.5 D e s c r i p t i o n and Evaluation of Composting T o i l e t Types A study of twenty-one makes of composting t o i l e t s was c a r r i e d out by the A g r i c u l t u r a l College of Norway[40]. It divided the t o i l e t s into two types, each with two sub-types. One type consisted of large-volume t o i l e t s , e i t h e r of the sloping f l o o r or box configuration; the other type consisted of small-volume t o i l e t s , e i t h e r with or without an e l e c t r i c heating element. Both the large box and small n o n - e l e c t r i c t o i l e t s received an o v e r a l l r a t i n g of 'Bad'; none of these i s commercially a v a i l a b l e i n Canada and they w i l l not be discussed further. Of the four t o i l e t s discussed i n t h i s t h e s i s , Clivus-Multrum and Toa-throne are large, sloping f l o o r types, while Mullbank. (Ecolet) and Humus-Toilet (Mulltoa) are small, e l e c t r i c a l l y - h e a t e d types. The l a s t three t o i l e t s were tested i n the above study and received an o v e r a l l r a t i n g of 'Good'; Clivus-Multrum was not included i n the study. In a d d i t i o n to s i z e , another obvious d i f f e r e n c e between large t o i l e t s and small t o i l e t s i s the approximately 30° angle at which the chamber f l o o r of the large types i s i n c l i n e d down toward the end from which the humus i s removed. The slope f a c i l i t a t e s aeration by draining l i q u i d to lower l e v e l s and by f o r c i n g f r e s h l y deposited material to flow over and around the a i r ducts that pass through the chamber at i n t e r v a l s . By the time the material slowly s l i d e s to the low end of the chamber, decomposition i s complete. 17 The e s s e n t i a l d i f f e r e n c e between the two types, however, i s the rate at which decomposition proceeds. R e c a l l i n g the d i s t i n c t i o n between moulder-ing and composting, the process i n Clivus-Multrum and Toa-throne i s moulder-ing, while the process i n Mullbank and Humus-Toilet i s composting. The slow r a t e i n the f i r s t two i s due mainly to the extreme aeration achieved i n the chamber and the r e s u l t i n g cooling e f f e c t on the p i l e . This requires r e t e n t i o n times f o r complete pas t e u r i z a t i o n of the excreta of up to several years and a correspondingly large volume to accommodate prolonged loading (Retention time i n the small t o i l e t s i s on the order of s i x months to a year). This unwieldy bulk, e s p e c i a l l y with the C l i v u s , requires i n s t a l l a t i o n of the chamber i n a basement or crawlspace, i f not outside, with excreta and other m a t e r i a l f a l l i n g i n t o the chamber v i a chutes. The usual i n s t a l l a t i o n c o n f i g -u r a t i o n of the Cl i v u s also requires that the kitchen and bathroom share a common w a l l [see diagram i n Appendix A]. These f a c t o r s are not important i n new houses, which can simply be designed around the t o i l e t , but although i n s t a l l a t i o n i n e x i s t i n g houses i s pos s i b l e , these i n s t a l l a t i o n requirements are one of the main disadvantages, along with the higher cost, of the large, sloping f l o o r t o i l e t s . The small t o i l e t s are obvious attempts to benefit from t h i s apparent weakness. The t o i l e t seat s i t s r i g h t on top of the decomposition chamber, and the whole u n i t i s e a s i l y i n s t a l l e d on a t y p i c a l bathroom f l o o r . To compensate f o r the s i z e reduction, the rates of decomposition and dehydration are increased by the a d d i t i o n of a temperature c o n t r o l system, using the heating element; mechanical v e n t i l a t i o n , using a fan; and s t i r r i n g / m i x i n g devices, which may also be e l e c t r i c a l l y - o p e r a t e d . The i n i t i a l economic cost i s t y p i c a l l y one-third as much as that of the C l i v u s . In terms of performance, however, these advantages are more apparent than r e a l . The inventor of the Clivus has made no attempt to modify i t s s i z e , ' 18 and maintains that the 160 cubic foot container i s the minimum volume f o r slow safe decomposition[51]. Two thousand of these t o i l e t s have been i n s t a l l -ed i n Sweden and according to the company, none has ever been removed from a home because of malfunctioning[18]. In contrast, various models of small t o i l e t s i n the recent past have experienced mechanical and hydraulic f a i l u r e , v e n t i l a t i o n and odour problems, urine overloading and accumulation, and evaporation rates high enough to dry the excreta before proper reduction of b i o l o g i c a l oxygen demand[18][40][42][51]. Many of these problems were serious enough to require complete removal of the t o i l e t . In f a i r n e s s to the small t o i l e t s , however, many of the problems can be traced to improper i n s t a l l a t i o n , use and maintenance, i n some cases because the t o i l e t came equipped with non-existent or inadequate i n s t r u c -tions^!?] [42] . Nevertheless, the performance data i n d i c a t e a d e f i n i t e need fo r design improvements, and i n at l e a s t one case these have been made. Humus-Toilet experienced many of the above-mentioned problems[18][42], but has r e c e n t l y undergone design changes to eliminate these problems, and there are now hundreds of the t o i l e t s i n s a t i s f a c t o r y operation under diverse conditions. [Appendix A contains a more d e t a i l e d d i s c u s s i o n of the four composting t o i -l e t s mentioned i n t h i s chapter, i n terms of a) design and p h y s i c a l charac-t e r i s t i c s ; b) capacity; c) i n s t a l l a t i o n and management requirements; d) monetary cost and energy requirements; e) past performance; and f ) o v e r a l l evaluation.] An evaluation of the two main types of t o i l e t i s also i n order. Small t o i l e t s cost much l e s s and are easier to i n s t a l l than large t o i l e t s . On the other hand, small t o i l e t s require e l e c t r i c i t y to operate, and therefore have a higher operating cost and are l i m i t e d i n use to areas where e l e c t r i c -i t y i s a v a i l a b l e (There would also be problems i f an e l e c t r i c a l blackout 1 9 l a s t e d f o r more than a few days). The int r o d u c t i o n of a r t i f i c i a l aids to decomposition also introduces things that can go wrong, and thus p o t e n t i a l maintenance costs are higher. In general, small t o i l e t s require more care and a t t e n t i o n on the part of the users. O v e r a l l , assuming i n s t a l l a t i o n requirements can be met (house design and p o s s i b l y power supply f o r large t o i l e t s , power supply for small t o i l e t s ) and equal standards of i n s t a l l a t i o n arid maintenance, large t o i l e t s are generally better than small t o i l e t s at providing safe trouble-free waste treatment, simply because they are more r e s i l i e n t . The r e s i l i e n c e of a sys-tem i s a measure of i t s a b i l i t y to cope with externally-imposed changes and s t i l l continue to function within design l i m i t s . In large t o i l e t s , the very largeness i t s e l f provides t h i s r e s i l i e n c e — an a b i l i t y to withstand under-loading, overloading, shock-loading[42] and occasional maintenance lapses on the part of the users. In small t o i l e t s , the smallness requires design complexities that i n e f f e c t reduce the r e s i l i e n c e of the system and make i t much more s e n s i t i v e to loading changes, i n t e r r u p t i o n i n power supply and continuous, c a r e f u l use and maintenance. This does not mean that small t o i l e t s should never be used or that they should be used only as a l a s t r e s o r t . On the contrary, there are many si t u a t i o n s where space or cost w i l l preclude or i n h i b i t the use of large t o i l e t s . Small t o i l e t s w i l l perform s a t i s f a c t o r i l y i n these s i t u a t i o n s , provided that t h e i r lower r e s i l i e n c e i s recognized and compensated f o r with a greater a t t e n t i o n paid to operation and maintenance requirements. In a d d i t i o n , not a l l small t o i l e t s w i l l perform with the same degree of dependability, and care should be taken during s e l e c t i o n that the t o i l e t i s designed to avoid the problems mentioned e a r l i e r . 20 B.6 Development of the Composting T o i l e t Concept In a d d i t i o n to refinement of e x i s t i n g t o i l e t s , work i s being c a r r i e d out i n Sweden and North America to increase the a p p l i c a b i l i t y of the concept and to reduce the cost of the system. The Swedish company which manufactures the Clivus-Multrum i s current-l y extending i t s a p p l i c a t i o n to multiple family dwellings[37]. The proposed system c o n s i s t s of vacuum t o i l e t s discharging to a large, c e n t r a l l y - l o c a t e d C l i v u s . Vacuum t o i l e t s use only a f r a c t i o n of the water used by normal f l u s h t o i l e t s , but an e l e c t r i c pump w i l l s t i l l be necessary to keep f l u i d c i r c u l a t i n g through the p i l e u n t i l i t can be evaporated. I t w i l l also prob-ably be necessary to add c e l l u l o s i c materials to generate more heat from the decomposition[26]. In response to the i m p r a c t i c a l i t y of i n s t a l l i n g the Clivus i n some e x i s t i n g houses, both Swedish and U.S. Clivus manufacturers are developing a system i n v o l v i n g a conveyor tube with an i n t e r n a l screw design to trans-port waste from i t s p o i n t - o f - o r i g i n to wherever the composting chamber can be conveniently located[26]. This means an increase i n the cost and a decrease i n the r e s i l i e n c e and s e l f - s u f f i c i e n c y of the t o t a l system, making the j u s t i f i c a t i o n of using the t o i l e t r e l y more on the e c o l o g i c a l and the psychic advantages of r e c y c l i n g body wastes. The Clivus-Multrum i s c u r r e n t l y the most expensive of a l l composting t o i l e t s , p a r t l y because of research costs and the low volume of production, and the U.S. company i s t r y i n g to reduce the cost to the point where the t o t a l system w i l l be competitive with a septic tank/leach f i e l d system[10]. But the greatest contributions toward making composting t o i l e t s a c c e s s i b l e to low income people are being made by individuals/groups who are designing composting t o i l e t s / p r i v i e s , s i m i l a r i n design to the C l i v u s but which can 21 be constructed by the user/owner f o r a materials cost of one hundred d o l l a r s or l e s s . Included among these i s Ken Kern, author of The Owner- B u i l t Home; Sim Van Der Ryn and the Farollones I n s t i t u t e ; and the Minimum Cost Housing Group at M c G i l l U n i v e r s i t y School of Arc h i t e c t u r e , d i r e c t e d by : Witold Rybczynski. D e t a i l s of these designs are contained i n Appendix C. Another development which would prove u s e f u l i n some s i t u a t i o n s i s suggested by a design i n the above book by Kern. His composting p r i v y i s a c t u a l l y part of a bathing-washing-toilet module, which includes a s o l a r water heater[see Appendix C]. I f a f l a t p l ate solar c o l l e c t o r were adapted f o r use with a composting t o i l e t , i t might do away with the need to have e l e c t r i c i t y a v a i l a b l e before i n s t a l l i n g a small t o i l e t , or before i n s t a l l i n g a large t o i l e t i n an unheated space. II.C THE GREYWATER SUB-SYSTEM C l Introduction Greywater i s the term f o r household waste emanating from kitchen, bathing and laundry f i x t u r e s . U n t i l the advent of systems l i k e compostim-; t o i l e t s which handle only t o i l e t wastes, i t was not v i s i b l e as a separate f r a c t i o n of domestic sewage. However, the exclusion of human excreta from the waste flow pointed up the r e l a t i v e lack of knowledge about the compos-i t i o n of greywater and appropriate methods of d i s p o s a l . Nevertheless, i t i s c l e a r that i f composting t o i l e t s are to be a s u i t a b l e a l t e r n a t i v e to conventional sewage systems, the key i s an acceptable method of greywater disposal/treatment. C.2 The Nature of Greywater The p r i n c i p l e c h a r a c t e r i s t i c of greywater, confirmed by the r e l a t i v e l y 22 few studies which have examined i t s composition, i s that greywater can "vary from time-to-time, place-to-place, and i n almost every conceivable way"[62]. Yet the very term "greywater", as opposed to the s i m i l a r l y value-laden term "blackwater" (denoting t o i l e t wastes), suggests that greywater i s l e s s ' d i r t y * than blackwater and therefore presents l e s s of a treatment problem. The a v a i l a b l e evidence generally supports t h i s view, although there i s considerable v a r i a t i o n among studies, both i n terms of what analyses were made and i n terms of the r e s u l t s when the same v a r i a b l e s were analyzed. These points are i l l u s t r a t e d i n Tables I and I I . An examination of these tables, along with other sources as noted, i n d i c a t e s a number of d i f f e r e n c e s , l i s t e d below, between greywater and blackwater, or between greywater and combined wastewater. The s i g n i f i c a n c e of these d i f f e r e n c e s l i e s i n t h e i r suggestion that acceptable greywater ' treatment can be markedly le s s d i f f i c u l t than the treatment of combined wastewater Biochemical oxygen demand. Most studies show that greywater contibutes about h a l f of the biochemical oxygen demand[21] [32][37], although one study has reported a f i g u r e of about-80%[46]. However, there are s i g n i f i c a n t d i f f e r e n c e s i n the rate of decomposition. A Swedish study shows that the decomposition of greywater i s 75% complete a f t e r f i v e days, whereas the decomposition of combined wastewater i s only 37% complete a f t e r f i v e days [21]. This f i n d i n g i s supported by the r a t i o of chemical oxygen demand (COD) to b i o l o g i c a l oxygen demand (BOD) column of Table I. As the resistance to biodegradation i s d i r e c t l y proportional to COD/BOD, t o i l e t North American experience indicates that BOD5 of combined wastewater i s about 70% of ultimate oxygen demand, based on a rate constant of 0.11[9]. This d i f f e r e n c e may r e f l e c t d i f f e r e n c e s i n sewage composition. 23 TABLE I a : , POLLUTION LOADS OF WASTEWATER SAMPLED FROM PLUMBING FIXTURES (milligrams/capita/day) PLUMBING FIXTURE BOD COD COD BOD N03-N NH4-N r ° 4 Mean % Mean % Mean % Mean % Mean % KITCHEN . SINK 9,200 19 18,800 16 2.04 7.6 10 74 2.3 173 1.4 BATHTUB 6,183 13 9,080 7 1.47 11.6 16 43 1.3 30 .3 BATHROOM SINK 1,860 4 3,250 3 1.75 2.2 3 9 .3 386 3.3 LAUNDRY MACHINE 7,900 16 20,300 17 2.57 35.3 49 316 9.8 4,790c 40.4 TOTAL GREYWATER 25,140 52 51,430 43 2.05 56.7 78 442 13.7 5,379 45.4 WATER b CLOSET 23,540 48 67,780 57 2.88 16.0 22 2,782 86.3 6,473 54.6 TOTAL POLLUTION 48,680 100 119,210 100 2.45 72.7 100 3,224 100.0 11,852 100.0 •NOTES: a Taken from Laak[32] b Water closet wastewater not sampled; these figures are estimates of human waste production. c Only high-phosphate detergents were used TABLE I I a : COMPARISON BETWEEN QUANTITIES OF POLLUTION PER DAY IN GREYWATER AND BLACKWATER ANALYSIS UNITS GREYWATER BLACKWATER TOTAL WA'JVKWATER PERCENT DIVISION GREYWATER BLACKWATER BOD 5 grams/capita/day 25.0 20.0 45.0 56 44 KMn04-04 48.0 72.0 120.0 40 60 Total P 2.2 1.6 3.8 58 42 Kjeldahl N 1.1 11.0 12.1 9 91 Total Residue - Fixed - V o l a t i l e 77.0 53.0 130.0 59 41 33.0 14.0 47.0 70 30 44.0 39.0 83.0 53 47 Nonfilterable Residue - Fixed - V o l a t i l e 18.0 30.0 48.0 38 62 3.0 5.0 " 8.0 38 62 15.0 25.0 40.0 38 62 Plate c.35° no. of bacteria 83.0 x l O 9 b 62.2 x l O 9 145.2 x l O 9 57 43 C o l i 35" per capita/day 8.5 x l O 9 b 4.8 x l O 9 13.3 x l O 9 64 36 C o l i 44° 1.7 x l O 9 b 3.8 x l O 9 5.5 x l O 9 31 69 Flow litres/cap/day 121.5 8.5 130.0 93 7 NOTES: a Taken from Lindstrom[37] b The average of the weighted arithmetic average values for the greywater from kitchens and bathrooms; the laundry i s not included 24 wastes appear to be the most r e s i s t a n t . Another table from the same source shows that i t i s the feces and t o i l e t paper that are the most r e s i s t a n t [ 3 2 ] . S o l i d s . The amounts of s o l i d s i n greywater and blackwater w i l l be e s p e c i a l l y dependent on v a r i a t i o n s within kitchens and laundry. One study found s u r p r i s i n g amounts of f i n e p a r t i c u l a t e s i n laundry water, i n the form of l i n t , g r i t and h a i r [ 2 8 ] , and kitchens w i l l vary as a source of s o l i d s according to the amount of food scraps going down the sink d r a i n . This p o t e n t i a l v a r i a t i o n i s confirmed by e x i s t i n g studies, i n which the propor- i t i o n of wastewater t o t a l s o l i d s contributed by greywater v a r i e s from 60%[37] to 75%[46]. The v a r i a b i l i t y i s even greater i n the percentages of f i l t e r a b l e and n o n - f i l t e r a b l e s o l i d s i n greywater—one study reports 77% f i l t e r a b l e solids[37] and another27%[46].(Some of t h i s v a r i a t i o n i s no doubt a t t r i b u -table to the composition of the water i t s e l f . ) A major d i f f e r e n c e between greywater and combined wastewater, of course, i s the absence i n greywater of l a r g e - s i z e d and slowly-decomposing s o l i d s ( i . e . , feces and t o i l e t paper). Nitrogen. Blackwater accounts for 70 - 90% of the t o t a l nitrogen i n waste-water[21][32][37][46], most of which comes from urine i n the form of ammonia-nitrogen (NH^-N)[32][46]. While greywater contains a greater proportion of highly-soluble n i t r a t e - n i t r o g e n (NO3-N), the t o t a l amounts of NO3-N are small r e l a t i v e to the amounts of NH^-N[32][46]. Phosphorus (PO4). From 45 -76% of the phosphorus found i n t o t a l wastewater comes from greywater[21][32[]37][46], but the amount i s very dependent on the type of detergent used i n the household. One study reports that 70% of the phosphorus i n greywater was due to detergents[21]. Chlorides. Chloride concentration i n greywater i s not s i g n i f i c a n t [ 2 8 ] , with most chlorides contributed by urine[21]. Bacteria. Although b a c t e r i a are present i n s i g n i f i c a n t amounts i n greywater [21][37][46], the majority of pathogenic b a c t e r i a are found i n 25 blackwater[37]• This i s one c h a r a c t e r i s t i c that w i l l vary tremendously across households, depending, for example, on the presence of a baby, r e f l e c t e d i n both a high b a c t e r i a count and high BOD i n the greywater. Grease. Greywater contains about 75% of the grease i n t o t a l wastewater[21] [46], but considerable amounts of t h i s may r e s u l t from food scraps and cooking grease, much of which can be prevented from j o i n i n g the grey-water stream. Temperature. Greywater i s about 50°C, whereas combined wastewater i s about 36°C[21]. Surge.flows. Greywater flows w i l l s t i l l be influenced by events such as simultaneous emptying of bathtub and washing machine, against which the surge e f f e c t of the t o i l e t i s not s i g n i f i c a n t [ 2 1 ] . Summary Conclusion. There are two d i f f e r e n c e s i n the p o l l u t i o n load between greywater and combined wastewater which are important i n regard to eventual treatment. The f i r s t i s a decrease i n the quantity of po l l u t a n t s i n greywater as opposed to combined wastewater, and the second i s a d i f f e r e n c e i n the q u a l i t y of the p o l l u t a n t s . In q u antitative terms, e l i m i n a t i o n of excreta from the wastewater stream w i l l r e s u l t i n a large reduction i n biochemical oxygen demand, t o t a l s o l i d s , phosphorus and pathogenic b a c t e r i a , and an even greater reduction i n highly-mobile elements (nitrogen and c h l o r i d e s ) . Furthermore, since the f l u s h t o i l e t i s responsible f o r 41 - 65 % of household water use[21][32], the t o t a l volume of wastewater r e q u i r i n g treatment w i l l be reduced by about h a l f . In q u a l i t a t i v e terms, the organic p o l l u t a n t s i n greywater are subject to more rapid decomposition, and the average s i z e of p a r t i c u l a t e s i s reduced. The implications of these dif f e r e n c e s are discussed i n the follow-ing s e c t i o n . 26 C.3 The Treatment of Greywater Although the s i t u a t i o n i s improving, there has been r e l a t i v e l y l i t t l e design e f f o r t to produce techniques f o r the treatment of greywater alone[62]. Therefore, many owners of composting t o i l e t s must continue f o r awhile to depend on treatment methods which were designed to handle combined waste-water, although the differences l i s t e d above permit m o d i f i c a t i o n of these systems when only greywater i s to be treated. The most conventional of these systems combines pre-treatment of the greywater i n a s e p t i c tank and disp o s a l i n a leach f i e l d or seepage p i t . This system can be used without modification i f already i n place, although the s e p t i c tank i s over-designed with respect to greywater since there are no large p a r t i c l e s to be s e t t l e d out. However, the main pre-treatment func-t i o n s of the s e p t i c tank — trapping grease, s e t t l i n g p a r t i c u l a t e s and accommodating surge flows — are s t i l l necessary. With e l i m i n a t i o n of t o i l e t f l u s h water, though, the leach f i e l d s i z e can be reduced by 50 %[21], or the l i f e t i m e of an e x i s t i n g t i l e f i e l d can be gr e a t l y prolonged[62]. The disad-vantages of the s e p t i c tank/leach f i e l d system remain, of course, that i t i s l i m i t e d by sub-surface conditions and that the nutrients i n the e f f l u e n t are e s s e n t i a l l y wasted. There i s also c o n f l i c t i n g evidence about the d e s i r a b i l i t y of anaerobic vs aerobic decomposition[21][62]. Other modified systems, which have gained acceptance i n some r e g u l -atory j u r i s d i c t i o n s , meet some but not a l l of the above objections by follow-ing a s e p t i c tank with a d i f f e r e n t d i s p o s a l technique. These include[21]: (1) Shallow Raised Seepage Beds, which minimize groundwater p o l l u t i o n and maximize n u t r i e n t uptake by plants; (2) I n f i l t r a t i o n Mounds, which are designed f o r high water table areas, but which are c o s t l y i n terms of space and money; and (3) Leaching Chambers, which are e s s e n t i a l l y pre-cast concrete leaching ' f i e l d s ' . 27 There have been several systems proposed f o r dealing s p e c i f i c a l l y with greywater, and these take advantage both .of the l e s s e r quantity of p o l l u t a n t s i n greywater as compared to combined wastewater, and of the change of q u a l i t y of the p o l l u t a n t s . The f a s t e r rate of decomposition and the decreased s i z e and quantity of p a r t i c u l a t e s permits use of a simple gravel f i l t e r as pre-treatment instead of a s e p t i c tank, or allows e l i m i n -a t i o n of pre-treatment altogether. Examples of such systems include[21]: (1) Leaching Chambers with No Pre-treatment, i n which a large-volume cham-ber (to accommodate surge flows) i s placed on a gravel bed; (2) Gravel  F i l l e d Seepage P i t (Dry Well) with No Pre-treatment, which i s inexpensive but wastes nu t r i e n t s and requires good s o i l p e r c o l a t i o n rates and deep or non-r-existent r e s t r i c t i n g l a y e r s ; (3) Pre-treatment F i l t e r s , necessary to prevent clogging of perforated d i s t r i b u t i o n pipes, and c o n s i s t i n g of a sand and/or gravel f i l t e r followed by a shallow seepage bed (one such system i s described i n Appendix D); and (4) Di r e c t Discharge to Water Body a f t e r  Aerobic Treatment, where, by c o n t r o l l i n g the amount of n u t r i e n t s l i k e n i t r o -gen and phosphorus which get into the greywater and by c a r e f u l treatment, the r e s u l t i n g e f f l u e n t may w e l l be of better q u a l i t y , and thus have a l e s s e r impact, than the e f f l u e n t from sewage treatment plants which i s also d i s -charged to water courses; nevertheless, t h i s a l t e r n a t i v e ' s e s s e n t i a l l y inappropriate f o r use with a system l i k e the composting t o i l e t which i s based on r e c y c l i n g . In e f f e c t , a l l of the systems described above, with the p o t e n t i a l exception of pre-treatment f i l t e r s , view greywater i n a negative sense, as something to be s a n i t i z e d and discharged to the environment as e f f i c i e n t l y as pos s i b l e . A more p o s i t i v e approach, and one i n keeping with the concept of the com-posting t o i l e t , would f i r s t reduce the quantity of greywater and contained p o l l u t a n t s and then re c y c l e greywater constituents f or further use. 28 Table H I suggests d i r e c t i o n s that might be taken to reduce t o t a l flows. TABLE I I I PERCENT OF TOTAL WATER USE OF EACH PLUMBING FIXTURE 3 KITCHEN BATHROOM LAUNDRY TOILET NOTE: a Taken from Laak[32] The most obvious target i s the bathroom, and a number of devices f o r reduc-ing the amount of water used i n bathing already e x i s t , i n c l u d i n g p o i n t - o f -use water heaters, intermittent-flow showers, thermostatic mixing valves and shower heads which mix a i r into the water stream to create the i l l u s i o n of v iOrme. As f o r the laundry, the low end of the range suggests that i t i s pos s i b l e to s i g n i f i c a n t l y reduce the volume used here, too. Equally important i s changing the nature of greywater p r i o r to t r e a t -ment, by reducing the quantity and changing the nature of po l l u t a n t s at the source. This strategy i s simple i n concept but d i f f i c u l t to implement. I t requires nothing l e s s than a fundamental change i n the environmental consciousness of i n d u s t r i a l designers and consumers of household goods such as cleaning agents — nothing s h a l l be put into the greywater stream which cannot be e f f e c t i v e l y treated or recycled from the stream. U n t i l t h i s can be achieved, and t h i s thesis i s not the place to go any further i n t o the subject, there i s an obvious need f o r convenient f a c i l i t i e s RANGE MEAN 5 - 1 6 9 12 - 40 26 4 - 2 7 18 4 1 - 6 5 47 Once the greywater i s generated, the goal should be r e c y c l i n g . With reference to Table I, the greywater coming from bathroom sink and tub c a r r i e s the lowest p o l l u t i o n load and, with appropriate treatment, could be reused i n the washing machine. The greywater generated by the laundry could, again with appropriate treatment, be used for purposes such as watering cars and gardens/lawns. "Appropriate" treatment would involve techniques to s t e r i l i z e the greywater and remove as many s o l i d s and dissolved nutrients as po s s i b l e , these being placed i n the composting t o i l e t . The CANWELL system developed by Central Mortgage and Housing Corporation might prove to be an appropriate technique[7]. And an a l t e r n a t i v e which makes good use both of the nutrients i n greywater and of the heat i t containsfsee page 25] involves sending the greywater, with varying degrees of pre-treatment, into a greenhouse a d j o i n -ing the dwelling where i t t r i c k l e s through the s o i l , g i v ing up i t s heat and nutrients and being p u r i f i e d i n the process[20][38], C.A Conclusion The composition of greywater v a r i e s greatly according to household and to the study which analyzes i t . Although there are major d i f f e r e n c e s i n r e s u l t s found by the few studies that have been c a r r i e d out, i t appears that i n quantity and q u a l i t y of p o l l u t a n t s , greywater does not present a serious treatment/disposal problem. Acceptable, i f not e n t i r e l y s a t i s f a c t o r y techniques of treatment e x i s t , based on modifications to sub-surface dispos-a l systems designed f o r combined wastewater. Not s u r p r i s i n g l y , none of these i s s u i t a b l e f o r a l l s o i l conditions. Also e x i s t i n g , a l b e i t i n an e a r l y stage of development, are systems that i n elegance of concept, s i m p l i c i t y of to which i n d i v i d u a l s and i n d u s t r i e s can take substances which are to x i c or otherwise d i f f i c u l t to handle, f o r subsequent n e u t r a l i z a t i o n and/or r e c y c l i n g . 30 operation and a b i l i t y to conserve and recycle p h y s i c a l materials, are f i t -t i n g companions to the composting t o i l e t . Therefore, with s u f f i c i e n t imag-i n a t i o n and determination, there should be few s i t u a t i o n s i n which the use of composting t o i l e t s i s precluded by the lack of an e f f e c t i v e system f o r t r e a t i n g greywater. II.D REGULATORY STATUS OF COMPOSTING TOILETS Composting t o i l e t s have generally gained approval from the approp-r i a t e regulatory agency, although i n l i g h t of uncertainty about the performance of a little-known and somewhat c o n t r o v e r s i a l technique, approv-a l has often been on an i n d i v i d u a l , almost experimental b a s i s . As more ac t u a l performance data are becoming a v a i l a b l e , t h i s f e e l i n g of caution i s gradually being replaced by d e f i n i t e guidelines f o r the use of composting t o i l e t s . An example of t h i s i s the State of Washington, which, as of September 16, 1975, has approved composting t o i l e t s i f use i s consistent with a set of guidelines, a copy of which i s i n Appendix E. The Washington State Department of S o c i a l and Health Services also has approved, "where approved hon-water c a r r i e d sewage di s p o s a l devices are used, a 50 % reduction i n sep t i c tank volume and a 40 % reduction i n d r a i n f i e l d s i z e . . . " f o r the purpose of greywater disposal[61]. In the State of Oregon, the Department of Environmental Quality has i n i t i a t e d a program to monitor over f i v e years the performance of f i v e makes of composting t o i l e t , i ncluding the four discussed i n t h i s t h e s i s . P o t e n t i a l nuisance and pub l i c health f a c t o r s associated with the t o i l e t s w i l l be explored[45] with a view to e s t a b l i s h i n g a regulatory procedure. In B r i t i s h Columbia, r e s p o n s i b i l i t y f o r approving composting t o i l e t s 31 r e s t s with the Health Branch of the Department of Health Services and Hos p i t a l Insurance. At l e a s t one t o i l e t , the Humus-Toilet i n 1975, has been granted approval by Administrative C i r c u l a r 75-104 as an a l t e r n a t i v e sewage dis p o s a l method under D i v i s i o n 8 of the B.C. Sewage Disposal Regulations, 1975. The C i r c u l a r , of which a copy i s included i n Appendix E, also advises that a reduction of 35 % i n the s i z e of the s e p t i c tank and f i e l d i s reason-able where such a system i s used for greywater d i s p o s a l . However, the r e g u l -atory status of the t o i l e t s i s somewhat experimental. The Health Branch has misgivings about the performance of some t o i l e t s [ 2 7 ] and does not f e e l that the composting t o i l e t should normally be considered f o r new su b d i v i s i o n s [ 3 ] . Furthermore, the Sewage Disposal Regulations s t i l l state that a l t e r n a t i v e sewage di s p o s a l systems may be permitted only when a s e p t i c tank or package treatment system cannot be used[4]. II.E EXISTING INSTALLATIONS Although composting t o i l e t s have been i n use i n Scandinavia f o r about t h i r t e e n years and i n North America, f o r f i v e years, there i s to date no community which has gone over e n t i r e l y to the composting t o i l e t . Dr. John Evans of Memorial U n i v e r s i t y i n Newfoundland attempted a few years ago to persuade a small community i n that province to i n s t a l l composting t o i l e t s as a s o l u t i o n to i t s sewage d i s p o s a l problems. The idea was not pursued a f t e r Dr. Evans became convinced that the t o i l e t he had i n mind, the Humus-T o i l e t , was unsuited to the conditions under which i t would be used[20]. As w e l l , he faced understandable reluctance on the part of the communities to be the f i r s t to go on such a program. (Dr. Evans' f a i t h i n the concept i s indicated by the t o i l e t he b u i l t himself and which now s i t s i n h i s bathroom[18][20].) 32 More recently, i n Prince George, B r i t i s h Columbia, the Sons of Norway r e c r e a t i o n a l a s s o c i a t i o n has proposed a r e s i d e n t i a l s u b d i v i s i o n of lake-front land i t owns, and a condition of residence i s the use of composting t o i l e t s . Houses i n the s u b d i v i s i o n w i l l be p r i m a r i l y used on a seasonal b a s i s . The sewage system, c o n s i s t i n g of Humus-Toilets and gravel f i l l e d seepage p i t s , has received approval from the l o c a l health inspector, and f i n a l approval i s expected a f t e r several problems raised by the Highways Department and the Regional D i s t r i c t of Fraser-Fort Feorge have been resolved[44]. And i n Alberta, the Alberta Housing Corporation has recently i n s t a l l -ed Humus-Toilets i n an eighteen u n i t housing program i n a northern Indian community, with another f i f t e e n unit i n s t a l l a t i o n planned for the near future. In addition, there are some seventy of the t o i l e t s i n s t a l l e d i n t r a i l e r s i n various northern l o c a t i o n s . Since none of the i n s t a l l a t i o n s i s i n areas serviced with piped water, the t o i l e t s have been r e a d i l y accepted as an a l t e r n a t i v e to the outdoor p r i v y and i n s p i t e of the l a t t e r being $300 cheaper. The program i s only about four months ol d , and the Housing Coporation and regulatory personnel are waiting for more feedback on per-formance before i n s t a l l i n g more u n i t s . The response to date i s s a t i s f a c t o r y [ 5 5 ] . While there have as yet been no community-scale i n s t a l l a t i o n s , there have been numerous sing l e i n s t a l l a t i o n s , i n several countries and under various c l i m a t i c conditions. In Sweden, the t o i l e t s are used p r i m a r i l y f o r r e c r e a t i o n a l dwellings and i n r u r a l areas, as they have been on t h i s contin-ent as w e l l . In a d d i t i o n to the i n s t a l l a t i o n s mentioned i n the above para-graphs, Humus-Toilets have been i n s t a l l e d i n A r c t i c o i l operations, north-ern construction camps, and w i l l be the sewage system i n a new "water subd i v i s i o n " proposed f o r the North Shore of Burrard I n l e t i n B.C.[29] Several Clivus-Multrums are also i n operation i n B r i t i s h Columbia, one i n 33 the Okanagan[36] and one i n the s k i lodge at Diamond Head i n G a r i b a l d i P r o v i n c i a l Park, with the p o s s i b i l i t y of use i n other parks dependent on i t s performance[13]. More information on e x i s t i n g i n s t a l l a t i o n s can be found i n Appendix A. H.F IS THE COMPOSTING TOILET A SUITABLE SEWAGE SYSTEM? The question of s u i t a b i l i t y i s best answered by applying f i v e c r i t e r i a . The f i r s t three are applicable to any sewage system: the system 1) does not create a hazard to human health; 2) does not create a hazard to the p h y s i c a l environment; and 3) does not create a nuisance i n achieving the f i r s t two requirements. The l a s t two are ap p l i c a b l e to sewage systems i n a Conserver Society: /the system 4) conserves the ph y s i c a l materials flowing through i t and recycles them into further uses; and 5) i s i t s e l f based on a technol-ogy which minimizes the use of energy i n general and non-renewable resources i n p a r t i c u l a r . (1) Does not create a hazard to human heal t h aiming proper i n s t a l l a t i o n , use and -laintenar.ce, composting t o i l e t s prevent or minimize human contact with pathogenic organisms during trans-p o r t a t i o n of sewage to the treatment area and during the treatment i t s e l f , which takes place within an impervious container. The f i n a l e f f l u e n t i s v i r t u a l l y pathogen-free and, when used sensibly, does not endanger human health. (2) Does not create a hazard to the p h y s i c a l environment Again assuming proper i n s t a l l a t i o n , use and maintenance, p o t e n t i a l p o l l u t a n t s are prevented from escaping i n t o the environment during the treatment phase, and the f i n a l e f f l u e n t i s i n a form that i s e a s i l y assim-i l a t e d by natural systems. Even i n the event of t o t a l , Catastrophic system 7 34 f a i l u r e , the environmental pollution w i l l be localized i n extent, within a single household, and limited in magnitude by the amount of waste produced by that single household. (3) Does not create a nuisance in the process of achieving the f i r s t two  requirements S t i l l assuming proper ins ta l la t ion , use and maintenance, composting toi le ts should give r ise to few i f any nuisance effects , and these of a localized nature. There is l i t t l e or no noise produced and the amount of odour vented to the atmosphere w i l l be indetectable beyond; a short distance from the roof vent. However, i t i s l i k e l y that problems of odour and insect infestation may be experienced from time to time within the household. These problems are relat ively minor i n some to i le ts and are associated with the t o i l e t ' s "break-in" period. In other t o i l e t s , they indicate room for design improvements. The common phrase i n each of the above paragraphs suggests the question, Is "proper ins ta l la t ion , use and maintenance" a r e a l i s t i c assump-tion? Composting t o i l e t s , especially the small type, undoubtedly require more care i n use and maintenance than do flush t o i l e t s . They part icularly require an understanding of the needs and l imits of a small ecosystem. Furthermore, composting to i le t 'plumbers' w i l l generally not be available, at least i n i t i a l l y , i n many areas, and individual owners must be responsible for solving problems that w i l l inevitably arise i n a new system. This may be viewed as a serious drawback by regulatory agencies who fear that the required level of technical and biological sophistication is unattainable by most people, and who therefore f e e l that sewage treatment i s best l e f t i n the hands of special ists at centralized locations. Contemplation of the costs and results of maintaining our present sewage systems w i l l put this argument i n the proper perspective. 35 More importantly, i f we agree that i n our i n d u s t r i a l i z e d society i n d i v i d u a l s have become alienated from t h e i r environmental support systems and do not recognize t h e i r r o l e i n the b i o - c y c l i n g of p h y s i c a l elements, and i f we agree that awareness of t h i s r o l e i s a d e s i r a b l e c h a r a c t e r i s t i c of people i n a Conserver Society, then the composting t o i l e t i s de s i r a b l e i n that i t promotes conscious p a r t i c i p a t i o n i n the proper d i s p o s a l of human excreta. (4) Conserves and recycles p h y s i c a l materials flowing through the system The composting t o i l e t meets t h i s c r i t e r i a almost by d e f i n i t i o n ; the t o t a l system produces a high-quality f e r t i l i z e r and reduces the amount of water used while permitting some or a l l of that amount to be recycled f o r furt h e r domestic use. (5) Minimizes the use of energy i n general and non-renewable resources i n  p a r t i c u l a r This c r i t e r i o n applies both to the energy and materials used i n manu-f a c t u r i n g the system and to the energy used i n operating and maintaining the system. At present, the most abundant materials i n most composting t o i l e t s are various kinds of p l a s t i c s and f i b r e g l a s s , which are f a i r l y energy-intensive and based on hydrocarbon energy stocks. Determination of whether the t o t a l energy/materials use i s more or l e s s than that used i n large, c e n t r a l i z e d sewage treatment plants, f or instance, requires a d e t a i l -a n a l y s i s which i s f a r beyond the scope of t h i s t h e s i s . However, owner-b u i l t designs have the p o t e n t i a l f o r minimizing the use of materials and energy, p a r t i c u l a r l y i f materials such as sulphur/ concrete blocks are used. And i n the future i t i s conceivable that p l a s t i c s can be produced from renewable resources such as wood f i b r e . As f o r energy use i n operation, care must be taken for small t o i l e t s i n c e r t a i n areas that the problem focus i s not simply s h i f t e d from waste 36 d i s p o s a l to energy demand/supply. The e l e c t r i c i t y consumption can be reduced by providing adequate i n s u l a t i o n and by i n s t a l l i n g them so that only a i r that has been heated (by the furnace, perhaps) i s drawn into the t o i l e t . The same precautions w i l l ensure that the large t o i l e t s need not increase household energy use at a l l , with the possible exception of enough e l e c -t r i c i t y to operate a small fan when natural d r a f t i s not s u f f i c i e n t . Composting t o i l e t s therefore have a d i r e c t energy cost of operation that v a r i e s according to the make and to the l o c a l climate; the s i g n i f i c a n c e of t h i s energy demand w i l l also vary, according to the energy sources and supply i n a s p e c i f i c area. Energy costs of composting t o i l e t s are discussed f u r t h e r i n Chapter I I I , but to put them into perspective, of major household e l e c t r i c a l appliances only the i r o n , clotheswasher and coffee maker have an annual demand f o r energy l e s s than that of the small t o i l e t s , and a l l four demand l e s s than two hundred kilowatt-hours per year[47] II.F CONCLUSION On the whole, the composting toile t ' i s indeed a s u i t a b l e sewage system, both i n terms of the needs of today's society and of a Conserver Society. The q u a l i f i c a t i o n s of t h i s judgement which do e x i s t concern d e t a i l s of design, not concept, and are more than acceptable i n l i g h t of the important benefits of a sewage system which does not cause environmental p o l l u t i o n and which conserves and recycles a valuable resource. This chapter has also i n d i c a t e d that c e r t a i n conditions may l i m i t the a p p l i c a b i l i t y of the composting t o i l e t system, eg., inappropriate house des-ign plus lack of e l e c t r i c i t y . The next two chapters w i l l i n part further explore the p o t e n t i a l of the composting t o i l e t system for use i n a v a r i e t y of s i t u a t i o n s . 37 CHAPTER I I I COMPARATIVE ANALYSIS OF SEWAGE SYSTEM ALTERNATIVES III.A INTRODUCTION Although Chapter II concluded that the composting t o i l e t i s a s u i t a b l e means of dealing with human body waste, there are l i k e l y to be many i n d i v i d -uals who perhaps f e e l that producing f e r t i l i z e r from sewage i s not s u f f i c -ient j u s t i f i c a t i o n f o r recommending the widespread replacement of conven-t i o n a l systems with composting t o i l e t s . In other words, the f e a s i b i l i t y of these t o i l e t s i n ac t u a l s i t u a t i o n s must also be demonstrated. The purpose of t h i s chapter i s therefore to compare composting t o i l e t s to the sewage systems c u r r e n t l y proposed i n each of two r e s i d e n t i a l areas. The two areas chosen for the comparison are both i n Surrey, B r i t i s h Columbia. As shown on Map 1, Bridgeview i s on the northern edge of Surrey and Panorama Ridge West i s i n the west-central portion of the m u n i c i p a l i t y . These communities were chosen both to test composting t o i l e t s i n as many si t u a t i o n s as research l i m i t s would allow, and because, recent cost data on conventional systems was a v a i l a b l e — e a c h community i s on the verge of development which w i l l involve additions to or replacement of the e x i s t i n g sewage system. A . l Methodology Information on each area was obtained from planning and engineering studies and through interviews with i n d i v i d u a l s i n the municipal planning and engineering departments. Information on the various sewage systems was obtained from engineering reports/firms and from interviews with or data received from the manufacturer and/or l o c a l d i s t r i b u t o r . 38 U . S A . 39 Two types of analysis have been c a r r i e d out. The f i r s t i s q u a l i t a t i v e i n nature and i s concerned with e f f e c t s r e l a t e d to land use and b i o p h y s i c a l systems. The second i s quantitative i n nature and i s concerned with monetary and energy costs. In comparing costs, the attempt was made to include as many costs as p o s s i b l e , with the major exception being sewer systems. Any sewage * system may be regarded as being composed of two s u b - s y s t e m s — c o l l e c t i o n and treatment. With composting t o i l e t systems., both of these sub-systems are contained within an i n d i v i d u a l household/lot. But with sewer systems, the treatment sub-system i s t y p i c a l l y outside the boundaries of communites the size of Bridgeview and Panorama Ridge West. Not only i s t h i s the case for these areas, but more importantly, i n Surrey both the treatment f a c i l -i t y (Annacis Island) and the trunk sewer mains which w i l l transport sewage from each community to the treatment plant are already i n existence, and the treatment plant i t s e l f i s operating only at 60 % of design capacity at the moment[56]. Thus the i n s t a l l a t i o n cost of the treatment sub-system and a major p o r t i o n of the i n s t a l l a t i o n cost of the c o l l e c t i o n sub-system i s e f f e c t i v e l y zero. There w i l l be operating and maintenance costs, but inasmuch as these w i l l be spread among various m u n i c i p a l i t i e s with a com-bined population of 300,000 persons[56], i t has been assumed that these costs are n e g l i g i b l e f o r the two areas and they have been ignored. Thus, when the composting t o i l e t system i s compared to a sewer system, the cost of the l a t t e r includes j u s t the cost of the part of the c o l l e c t i o n sub-system within the boundary of the community. A true cost comparison, i n In t h i s context, and generally throughout the t h e s i s , the term "sewage system" includes a l l systems which deal with human sewage i n any way. 40 communites which do not yet have any parts of a sewage system i n place, w i l l be correspondingly more favourable to the composting t o i l e t system. III.B DESCRIPTION OF STUDY AREAS B . l Bridgeview (a) H i s t o r i c a l and phy s i c a l d e s c r i p t i o n Bridgeview i s one of the older parts of Surrey and developed i n the l a s t century as r e s i d e n t i a l land f or workers i n m i l l s along the Fraser River or i n i n d u s t r i e s across the r i v e r i n New Westminster. As shown on Map 2, i t i s bounded on the North by the Fraser; on the West by P a t t u l l o Bridge; on the South by the King George Highway to 132 Street, then north on 132 Street to 114 Avenue and along the Greater Vancouver Sewer and Drainage D i s t r i c t trunk sewer l i n e to 136 Street, i t s boundary on the East. The community l i e s almost completely within the f l o o d p l a i n of the Fraser River and has the c h a r a c t e r i s t i c f l a t topography and high water table of a f l o o d p l a i n . I t i s protected from r i v e r f l o o d i n g by dykes and assoc-iat e d drainage channels, but floodgates, dykes and pumps are i n poor con-d i t i o n . The r e s u l t i n g increased r i s k of fl o o d i n g has been One of the f a c t o r s i n h i b i t i n g badly-needed improvements to the housing stock. The area i s also subject to flooding by runoff from the uplands immediately to the South, a problem which i s growing as increasing development on the uplands f u r t h e r reduces the absorptive capacity of the land. The high water table and poor drainage have resulted i n widespread malfunction of s e p t i c tank drainage f i e l d s and contamination of groundwater[54]. Sub-surface conditions create other problems as w e l l as poor drainage. Almost the e n t i r e area i s covered by peat deposits of varying depth, and underlying the peat i s a layer of organic and inorganic s i l t s . Below the 42 s i l t s are deposits of compact or dense a l l u v i a l sands or dense,granular t i l l , of undetermined thickness. While the sand i s stable enough to support sub-s t a n t i a l foundation loads, the peats and s i l t s experience considerable settlement under comparatively small loads. Thus there i s settlement damage to roads, u t i l i t i e s and houses[54]. Bridgeview has now been designated a Neighbourhood Improvement Program area, which w i l l make i t e l i g i b l e f o r R e s i d e n t i a l R e h a b i l i t a t i o n Assistance Pro-gram funds as w e l l . These funds w i l l be used to upgrade p h y s i c a l f a c i l i t i e s i n the community, connect residences to the new sewage system and, i n conjunction with the Assisted Home Ownership Program, may be used to relocate i n the r e s i d e n t i a l core a portion of those residents now l i v i n g i n the i n d u s t r i a l area or i n the areas proposed by the Community Plan[54] f o r t r a n s i t i o n to i n d u s t r i a l use. (b) The proposed sewage system An economically f e a s i b l e sewage system has been f o r years a major obstacle to the redevelopment of Bridgeview. The presence of compressible layers of peat and s i l t to depths approaching 15 metres over most of the area, and the f a c t that the area i s almost l e v e l , make i t impossible to i n s t a l l sanitary sewers i n the usual way, and d i f f i c u l t / e x p e n s i v e to i n s t a l l them using complex engineering techniques[39]. Many studies over the years have therefore concluded that sewering was not f e a s i b l e [ 8 ] . Recently, however, Surrey Council has approved the i n s t a l l a t i o n of a vacuum sewer system which i s easier and l e s s expensive to i n s t a l l than the usual g r a v i t y or pressure sewer system[8][39]. Construction i s expected to begin i n June 1977 (when the water table i s low enough); simultaneously, new storm drains, water mains and sidewalks w i l l be i n s t a l l e d and improvements made to the r i v e r f l o o d c o n t r o l system. 43 Also proposed, but rejected i n favour of the vacuum sewers, were package treatment systems. While the purpose of t h i s t h e s i s i s not to com-pare and evaluate the many a l t e r n a t i v e s to conventioanl systems other than composting t o i l e t s (a recent p u b l i c a t i o n gives an overview of s i x t y - s i x d i f f e r e n t systems[50]), the i n d i v i d u a l package treatment plant appears to be an obvious a l t e r n a t i v e to the composting t o i l e t i n many cases. I t has therefore been included i n the comparison i n both study areas, although not to the same l e v e l of d e t a i l as the other systems. One system not proposed for Bridgeview, because of drainage problems, . i s the s e p t i c tank/leach f i e l d or any other system that involves i n f i l t r a -t i o n of wastewater. This was also the major reason f o r choosing Bridgeview as a study area. I f there i s any weakness i n the composting t o i l e t system, i t i s the greywater sub-system, most current examples of which r e l y on i n f i l t r a t i o n to a greater or l e s s e r extent. I t was therefore f e l t that the conditions i n Bridgeview would provide a s i g n i f i c a n t t e s t of the f e a s i b i l i t y of the composting t o i l e t system. B.2 Panorama Ridge West (a) P h y s i c a l d e s c r i p t i o n Panorama Ridge West i s a low density, r e l a t i v e l y high income residen-t i a l area characterized by extensive tree cover and a r u r a l atmosphere. I t i s bounded on the North by Highway 10, on the South by the lowlands north of Colebrook Road, on the East by the King George Highway and on the West by Scott Road/120 Street, as shown on Map 3. The land slopes gently to the South over most of the area, but slopes steeply to the lowlands at the southern edge. The s o i l s are sandy loams and loamy sands[5]. Although d e t a i l e d knowledge of the depth of the s o i l s i s NOTE: The subdivision proposal presented to Surrey Council i s indic a t e d by the shaded area MAP 3: PANORAMA RIDGE WEST Scale: 1 inch = 2000 feet 4> 45 l a c k i n g , i t i s l i k e l y that as i n other areas of B r i t i s h Columbia's Lower Mainland, ther e . i s a layer of dense, impermeable g l a c i a l t i l l at an.approx-imate depth of 1.2 metres over most of the area, with the p o s s i b i l i t y of permeable pockets i n some l o c a t i o n s . Septic tank/leach f i e l d i s the only type of sewage system cu r r e n t l y used i n the area and there do not appear to be any problems with t h i s method to date[30]. However, i n addition to the uncertain (but probably shallow) depth to a r e s t r i c t i n g l a y e r , there i s apparently a high water table i n the area during parts of the year, judging from the amount of water i n the drainage ditches during these times[30]. (b) The proposed sewage system Panorama Ridge West i s not within Surrey's designated Urban Growth Areas, but the municipality has been under pressure since 1971 from devel-opers who want to create r e s i d e n t i a l subdivisions i n the western portion of the Ridge at d e n s i t i e s approaching those of suburban subd i v i s i o n s . The proposals met with strong opposition from l o c a l residents who feared the loss of the r u r a l s e t t i n g and expressed concern about p o s s i b l e groundwater p o l l u t i o n r e s u l t i n g from increased density of leach f i e l d s . As a way of responding to both concerns, Council made higher density subdivision dependent on the p r o v i s i o n of sewer service by the developer. + Most recent l y , however, a sewered su b d i v i s i o n of 200- l o t s at a density of about 2.7 gross l o t s / a c r e (current zoning i s 2.0 gross l o t s / a c r e ) has been proposed f o r the shaded area on Map 3. It also met with consider-able resistance and has been rejected i n i t s present form. Council i s awaiting completion of a community plan f o r the area before entertaining further s u b d i v i s i o n proposals[11] Panorama Ridge West was chosen f o r the comparison f o r several reasons 46 r e l a t i n g to the t e s t i n g of composting t o i l e t s , F i r s t , i n contrast to Bridgeview, sub-surface conditions are much more favourable f o r the i n s t a l l -a t i o n of septi c tank leach f i e l d s and gr a v i t y sewers. Second, there i s greater v a r i a b i l i t y i n topography/landform. And t h i r d , the area i s r e l a t i v e l y undeveloped, o f f e r i n g greater scope f o r f l e x i b i l i t y i n the pattern and l o c a -t i o n of housing development and providing the opportunity to compare the various systems f o r new, rather than e x i s t i n g housing. III.C THE COMPARISON C l Bridgeviev; (a) D e s c r i p t i o n of systems The vacuum system to be i n s t a l l e d i n Bridgeview i s marketed by Vacusan Systems Ltd. of Vancouver, and the proposed i n s t a l l a t i o n pattern i s i l l u s t r a t e d i n Figure 1. E x i s t i n g s e p t i c tanks w i l l be f i l l e d i n , e x i s t i n g plumbing f i x t u r e s w i l l be connected by g r a v i t y pipes v i a " i n t e r f a c e v a l v e s " to a vacuum sewer l i n e i n the st r e e t which w i l l carry wastewater to one of two c o l l e c t i o n s t a t i o n s . From there i t w i l l be discharged to an e x i s t i n g trunk sewer. The composting t o i l e t system w i l l include the Humus-VToilet and a greywater treatment unit that produces water of s u f f i c i e n t l y high q u a l i t y to be recycled within the household and/or discharged through shallow gravity pipes to the new storm drains. Humus-Toilet i s proposed instead of Clivus-Multrum for two reasons: (1) houses i n Bridgeview do not have base-ments because of the high water table[60], thus few i f any houses could accommodate the C l i v u s ; and (2) the average family s i z e i n Bridgeview i s only 3.1 persons[24], thus the r e s u l t i n g waste volume w i l l be w e l l w i t h i n 47 FIGURE 1: VACUUM SEWER SYSTEM - TYPICAL INSTALLATION PATTERN the designed capacity of the new Humus-Toilet models. T h e possibility exists, of course, that Clivus-Multrums could be installed i n any new housing that i s b u i l t . The representative package treatment system is an aerobic batch treat-ment plant, sold by Northern Purification Services Ltd. of North Vancouver, one of whose CA-5E models would be installed for each household. Since this system is designed to produce an effluent containing only about 20-25% of the original BOD and suspended solids[58], the sections of composition and treatment of greywater in Chapter II suggest that a gravel f i l t e r w i l l provide sufficient additional treatment to permit discharge to the storm drain. 48 (b) Effects on land use and biophysical systems 4 There w i l l be few i f any differential effects among the three systems on land use in Bridgeview. Conditions affecting sewage systems are uniform over the area and the physical pattern of the community is already well-established. There may be some changes as a result of implementing the community plan, but these could l i k e l y be accommodated equally easily by any of the sewage systems The systems do have different effects on biophysical systems, though: Vacuum sewers. Since the vacuum sewer system i s only a technical change in the collection sub-system wiuain the community, i t s effects beyond the point of discharge depend entirely on whether or not the nature of the wastewater flow i s changed. Although the installation of vacuum t o i -lets as well as vacuum sewers would reduce the flush volume from about 22 l i t r e s to 1.2 l i t r e s , with corresponding cost reducing implications for the whole system[8], installation of such toilets in Bridgeview would be imprac-t i c a l and, at $1000 per household, uneconomic[63]. Therefore, there w i l l be no change in wastewater volume and thus most of the problems mentioned i n Chapter I as being associated with modern treatment f a c i l i t i e s are also asspc-iated with vacuum sewer systems. The construction process i t s e l f w i l l have adverse effects on tbe community. Aside from the inconvenience and disruption experienced i n any community during a large-scale construction program, there w i l l be damages to the physical environment. Both the installation along every other side property line of interface valves and connections from house to street sewer, and the installation of the street sewers along rights-of-way i n front of the properties, in order to minimize possible settlement, w i l l require sub-stantial clearance of trees and other growth and w i l l cause inconvenience 49 to individual property owners, The consulting engineering f i r m involved i n the program feels that this impact is j u s t i f i a b l e " since i t w i l l result i n the greatest economy over the l i f e of the system"[8]. The system also requires sufficient surface area and rights-of-way to construct the two collector stations. The stations themselves w i l l be located on two vacant l o t s , and thus should have l i t t l e or no adverse effects on the visual landscape or community ac t iv i ty patterns. They could, i n fact , have a positive effect , assuming appropriate landscaping and design. Composting t o i l e t s . The physical impacts of i n s t a l l i n g composting to i le ts w i l l be contained within individual houses, and i n most cases w i l l be s l i g h t . It w i l l usually be desirable, i f not necessary, to remove the existing to i le t f ixture in order to make space i n the bathroom for the Humus-Toilet. In houses where the bathroom is too small, more exten-sive alterations must be made, depending on the design of the house, or the t o i l e t may be located i n a room other than the bathroom. The only other physical change which w i l l be required, with the possible exception of i n s t a l l i n g an e l e c t r i c a l outlet , i s the cutting of a hole i n the room c e i l i n g and i n the roof for the venti lat ion stack. For the greywater sub-system, the main effects w i l l be associated with connecting the outlet to the storm drain, i . e . damage and/or removal of sur-face vegetation, similar to the effects of i n s t a l l i n g the house connection i n the vacuum sewer system. However, the absence of the interface valve should permit simpler, shallower i n s t a l l a t i o n , for which hand tools w i l l be suitable, thus minimizing damage to vegetation. The effects of the treatment unit i t s e l f are not l i a b l e to be great, and w i l l depend on whether i t can be instal led inside or outside the house. The ins ta l la t ion process w i l l cause some inconvenience, noise and disruption to household routine, but i t i s important to remember that the 50 timing of the impacts w i l l u s ually be under the c o n t r o l of the residents of each house. In f a c t , i n most cases the i n s t a l l a t i o n could be c a r r i e d out by the residents themselves, with assistance from a person trained by the t o i l e t d i s t i b u t o r [ 2 9 ] . Package treatment. The e f f e c t s of i n s t a l l i n g t h i s system would be s i m i l a r i n nature to the e f f e c t s of i n s t a l l i n g a s e p t i c tank, although the greater bulk of the CA-5E w i l l require a l a r g e r excavation than f o r the usual s i z e of sep t i c tank. I t may even be d e s i r a b l e to remove the old s e p t i c tank and place the new unit i n the enlarged hole. Damage to the surface would thereby be minimized, but some damage to surface vegetation may be unavoidable i n many cases. (c) Monetary and energy costs Vacuum sewers. Monetary costs were obtained both from an engineering feas-i b i l i t y report[8] and from the Surrey Engineering Depart-ment[60]. Energy cost data were obtained from Vacusan Systems Ltd.[63] and from B.C. Hydro. The engineering report gives cost f i g u r e s of the sewer i n s t a l l a t i o n alone f o r three options r e l a t i n g to the s p a t i a l extent of i n s t a l l a t i o n . The a c t u a l system that w i l l be i n s t a l l e d goes beyond even the t h i r d option, "Bridgeview - Expanded Core Area", and includes the i n d u s t r i a l areas as w e l l , f o r a t o t a l cost of sewering alone of $3.8 m i l l i o n [ 6 0 ] . Because of l a c k of data on the i n d u s t r i a l area, the a n a l y s i s has been done f o r the r e s i d e n t i a l areas only, using the figures from the engineering report. Nevertheless, composting t o i l e t s are equally a p p l i c a b l e to i n d u s t r i a l uses, at l e a s t f o r handling human wastes[29]. Estimated t o t a l system costs, i n c l u d i n g property a c q u i s i t i o n , damage compensation and operating costs, are summarized i n Table IV, with relevant 51 TABLE IV MONETARY COSTS OF VACUUM SEWER SYSTEM - BRIDGEVIEW A. SEWER INSTALLATION a - SUMMARY OF COSTS b ( d o l l a r s ) Nature of Costs Bridgeview Core (Present Pop.) Bridgeview Core (Expanded Pop.) Bridgeview Expanded Core Vacuum hardware c 459,077 526,075 660,000 Main l i n e ($18/foot) 702,000 774,000 1,020,600 Inspection Cambers ^ ($30 each) 16,500 19,500 30,000 Interface valve boxes^ ($100 each) 40,000 50,000 75,000 Force main ^ ($40/foot) 144,000 144,000 144,000 Buildings ^ ($36,000 each) 72,000 72,000 72,000 SUBTOTAL 1,433,577 1,585,575 2,001,600 B. PROPERTY ACQUISITION & DAMAGE COMPENSATION 70,000 87,500 131,250 TOTAL INSTALLED COST 1,503,577 1,673,075 2,132,850 C. OPERATING COSTS (annual) Water—purchased by Surrey from GVWDf 1,200 1,500 2,250 Energy ^ 6,869 6,869 6,869 TOTAL OPERATING COST 8,069 8,369 9,119 NOTES; a Taken from Bridgeview: Sanitary Sewers F e a s i b i l i t y Study[8] b 1976 pr i c e s c Supplied by Vacusan Systems Ltd.; includes 10% f o r contingencies d Includes 20% for engineering and contingencies e Preliminary estimates, obtained from Surrey Engineering Dept. f Calculations and assumptions i n Appendix F 52 assumptions and c a l c u l a t i o n s i n Appendix F. Maintenance of the system w i l l involve weekly, monthly and yearly service checks performed by a c u r r e n t l y -employed municipal worker trained by the d i s t r i b u t o r to perform these tasks as only part of his/her regular duties. I t was therefore assumed that t h i s cost was n e g l i g i b l e i n r e l a t i o n to other costs, and not worth the e f f o r t required to separate i t from the t o t a l operating costs of the mu n i c i p a l i t y . Composting t o i l e t s . ,Monetary and energy cost data were obtained from promotional l i t e r a t u r e and s p e c i f i c a t i o n s , from i n t e r -views with the Humus-Toilet d i s t r i b u t o r and from B.C. Hydro. Although i t was assumed that only Humus-Toilet would be i n s t a l l e d , f i g u r e s f o r the Cli v u s are also presented to in d i c a t e part of the range of composting t o i l e t p r i c e s . The C l i v u s i s the most expensive t o i l e t on the market, and the Humus-Toilet i s one of the higher-priced small t o i l e t s . Appendix F describes the c a l c u l -ations and assumptions and Appendix.A contains much of the information mentioned i n the f i r s t sentence of t h i s paragraph. Unfortunately, the actual cost of the greywater sub-system could not be determined. At l e a s t one new system i s on the verge of being introduced . on the market, but neither d e t a i l s of i t s operation nor i t s exact p r i c e were a v a i l a b l e at time of w r i t i n g . I t s expected p r i c e , however, w i l l be about $850[29], and although i t i s l i k e l y that other, e q u a l l y - e f f e c t i v e systems are or soon w i l l be a v a i l a b l e at one-third to one-half that p r i c e , i t i s t h i s f i g u r e that i s used i n order to provide tbe most conservative estimate of the p r i c e of a greywater sub-system that i s s u i t a b l e f o r the s p e c i a l conditions e x i s t i n g i n Bridgeview. Other costs of the t o t a l system include the cost of i n s t a l l a t i o n and the cost of connecting the greywater sub-system to the storm dr a i n . Some of the f i g u r e s are based on 'expert' opinion and every attempt has been made to err on the side of caution when estimating a cost f o r which precedent i s 53 l a c k i n g . However, i f the costs s t i l l appear too low, i t i s because of the assumption that as much as possible of the labour w i l l be contributed by the residents of the household. This assumption appears to be reasonable i n l i g h t of the r e l a t i v e l y simple i n s t a l l a t i o n requirements and the f a c t that i n most cases, the i n d i v i d u a l household w i l l bear the t o t a l cost of the system d i r e c t l y , and w i l l thus wish to reduce i t s cash outlay as much as p o s s i b l e . This issue i s also discussed i n Chapters IV and V. Another way to deal with the uncertainty surrounding the greywater sub-system, of course, i s to subtract the i n s t a l l e d cost of the composting t o i l e t i t s e l f from the t o t a l cost of a l t e r n a t i v e systems such as g r a v i t y sewers which do not separately t r e a t greywater. 'The d i f f e r e n c e i s then the amount of money that could be paid f o r an i n s t a l l e d greywater sub-system and s t i l l keep the t o t a l system competitive with the a l t e r n a t i v e . Table V summarizes the costs of the t o t a l system: TABLE V: UNIT COST OF COMPOSTING TOILETS - BRIDGEVIEW (Dollars) NATURE OF COST CLIVUS-MULTRUM HUMUS-TOILET T o i l e t Unit a 1,850 b 790 c - I n s t a l l a t i o n d 200 e 100 Greywater Treatment Unit 850 850 - I n s t a l l a t i o n d 50 50 - Connection to storm drain ^  100 100 TOTAL INSTALLED COST 3,050 1,890 Operating Cost - Annual cost of energy 4^ 8 NOTES: FOB Vancouver, not FOB j o b - s i t e 1976 p r i c e for model with 4 - 7 person capacity d Estimated 1977 p r i c e of model H-10, i n c l u d i n g 20% volume discount[29] Assumes as much labour as possible supplied by residents ^ When house design permits ( Cost of v e n t i l a t i o n fan only; assumes appropriate i n s u l a t i o n 54 Package treatment. Table VI presents cost f i g u r e s provided by Northern P u r i f i c a t i o n Services (NPS), and are based on the pro-posal made by that company to supply sewage treatment equipment i n Bridgeview. It should be pointed out that the maintenance costs make no allowance f o r r e p a i r of malfunctions. A recent case study of an NPS package treatment plant s i m i l a r to the one used i n t h i s comparison concluded that the system was subject to frequent breakdown and was not c o n s i s t e n t l y capable of pro-ducing e f f l u e n t i n the 30-40 mg/1 BOD5 range required to j u s t i f y r e l a x a t i o n of d r a i n f i e l d s ize[23]. Since that study was made, and i n f a c t following many of i t s recommendations, NPS has extensively redesigned the plant, i n c l u d i n g more sophisticated c o n t r o l s , and now f e e l s confident that with proper maintenance every one to two months, the CA-5E w i l l provide depen-dable performance[58]. Nevertheless, the s i t u a t i o n i s somewhat s i m i l a r to that of the small composting t o i l e t s : the more t e c h n o l o g i c a l l y complex a system i s , the greater i s the p r o b a b i l i t y that something, sometime w i l l go wrong. TABLE VI UNIT COST OF PACKAGE TREATMENT - BRIDGEVIEW (Dollars) Batch treatment plant - CA-5E 2,277 - I n s t a l l a t i o n 623 - Less 20% volume discount 580 Greywater treatment unit 300 - I n s t a l l a t i o n a 50 TOTAL INSTALLED COST 2,670. Annual operating costs - Maintenance - mandatory service 96 - pumps replaced 48 - Energy 141 - Water (cost to Surrey) 3_ TOTAL ANNUAL "OPERATING COST • 288 NOTE: Assumes as much labour as possible supplied by residents 55 Normalized comparison. Since the vacuum sewer system cost i s for the whole community while the system costs of the other two systems are on a unit b a s i s , a unit cost f o r the vacuum sewer system was determined, based on the 604 dwelling units presently e x i s t i n g i n Bridgeview [54], In Table IV, Part A there i s a l i n e a r r e l a t i o n s h i p between t o t a l cost and number of u n i t s . The t o t a l cost of s e r v i c i n g 604 u n i t s was therefore ob-tained by interpolation[Appendix F ] , r e s u l t i n g i n a f i g u r e of $1,863,700 and a unit cost of $3086, compared to unit costs of $1890 and $2670 f o r the composting t o i l e t and package treatment systems, r e s p e c t i v e l y . Cd) Summary analysis The composting t o i l e t system has been compared to a vacuum sewer sys-tem and to a package treatment system i n terms of e f f e c t s on land use and b i o p h y s i c a l systems and of monetary and energy cost. Since Bridgeview i s already developed and condit ions a f f e c t i n g sewage systems are r e l a t i v e l y uniform over the community, none of the systems w i l l have an appreciable e f f e c t on land use. Biophysical systems within the community w i l l be a f f e c t e d by the '. i n s t a l l a t i o n of a l l three systems. Vacuum sewers w i l l have the greatest e f f e c t , causing general inconvenience and d i s r u p t i o n during the construc-t i o n phase and r e q u i r i n g the removal of trees and other vegetation from sewer l i n e rights-of-way along streets and on each property. Package t r e a t -ment systems w i l l r e s u l t i n some s o i l disturbance and vegetation damage on each property during excavation for the treatment plant and f o r connecting i t to the storm drain i n the s t r e e t . Composting t o i l e t s w i l l also require disturbance of a narrow s t r i p of each property during i n s t a l l a t i o n of the greywater sub-system, and i n a d d i t i o n w i l l require some a l t e r a t i o n s within each residence. 1 56 Table VII summarizes the t o t a l and unit costs of a l l three systems and shows that the composting t o i l e t system costs considerably l e s s money to i n s t a l l and operate than the other two systems, and uses an even smaller f r a c t i o n of energy, e s p e c i a l l y compared to the package treatment system. With respect to energy costs, i t i s i n t e r e s t i n g to note that although'the energy cost of the Humus-Toilet i s 57% that of the vacuum sewer system i n terms of d o l l a r s , i t s energy cost i s only 37% that of the vacuum sewer system i n terms of kilowatt-hours. This i s yet another example of how e l e c t r i c i t y rates i n t h i s province are biased i n favour of large users of energy. I t i s conceivable that a future r e v e r s a l of the ra t e s t r u c t u r e , not to mention an increase i n the absolute cost of energy as w e l l , w i l l make the energy cost advantage of the composting t o i l e t system even more pronounced. TABLE VII TOTAL AND UNIT COSTS OF ALTERNATIVE SEWAGE SYSTEMS - BRIDGEVIEW SEWAGE SYSTEM TOTAL SYSTEM COST COST PER HOUSEHOLD INSTALLED COST ANNUAL OPERATING COST INSTALL -ED COST ANNUAL OPERATING COST MONETARY ($) ENERGY (kwh) MONETARY ($) ENERGY (kwh) MAINTEN-ANCE WATER ENERGY TOTAL MAI NT. WATER ENERGY TOTAL VACUUM SEWERS 1,863,700 - 1,812 6,869 8,683 322,200 3,086 - 3 11 14 533 COMPOST-ING TOILETS 1,141,560 - - 4,832 4,832 109,928 1,890 - 8 8 182 PACKAGE TREATMENT 1,612,680 86,976 1,812 8 5 , 1 6 4 | 1 7 3 , 9 5 2 j i 1,874,212 2,670 144 3 1 4 1 i 2 8 8 3,103 57 C.2 Panorama Ridge West (a) Description of systems Four systems w i l l be compared f or t h i s area i 1) s e p t i c tank/leach f i e l d , c u r r e n t l y e x i s t i n g ; 2) aerobic batch treatment plant, discharging to a leach f i e l d ; 3) gravity sanitary sewers, discharging to the Greater Vancouver Sewer and Drainage D i s t r i c t ' s South Surrey C o l l e c t o r ; and 4) com-posting t o i l e t s (Clivus and Humus), plus greywater treatment that recycles water for domestic uses, any surplus being discharged to a garden or a shallow r a i s e d seepage bed. (b) E f f e c t s on land use and b i o p h y s i c a l systems Septic tank/batch treatment plant. These systems are considered together because of t h e i r e f f e c t u a l s i m i l a r i t y ; the only s i g n i f i c a n t d i f f e r e n c e between them i s that the e f f l u e n t q u a l i t y of the batch treatment plant i s higher than that of the s e p t i c tank, and therefore requires a smaller leach f i e l d . The magnitude of the d i f f e r e n c e i n f i e l d s i z e depends oh the s o i l type[4][33]. The main land use e f f e c t of these systems i s t h e i r influence on sub-d i v i s i o n l o t density for a given s o i l type. In most of Panorama Ridge West, i t i s probable that up to a c e r t a i n density, there w i l l be few problems r e s u l t i n g from these systems because s o i l drainage i s r e l a t i v e l y good and uniform. However, as mentioned i n Section III.B.2, there i s l i t t l e known about the v a r i a b i l i t y of depth to a r e s t r i c t i v e l a y e r or about the movement of groundwater downslope and into the lowlands. I t i s conceivable that beyond a c e r t a i n density, there i s danger of groundwater p o l l u t i o n and unacceptable movement of e f f l u e n t beyond the boundaries of the l o t where i t o r i g i n a t e d . The use of these systems therefore imposes r e s t r i c t i o n s on the 58 density and i n t e r n a l pattern of some subdivisions as w e l l . An example of the l a t t e r r e s t r i c t i o n i s the southern edge of the area where the ridge slopes down to the lowlands at a grade of about 30%[11]. I n s t a l l a t i o n of t i l e f i e l d s i s always more problematic when the slope exceeds 25%[41] and i s l i m i t e d i n B r i t i s h Columbia, assuming s u i t a b l e s o i l conditions, to slopes of l e s s than 30%[4]. The disturbance of the land surface r e s u l t i n g from i n s t a l l a t i o n of these systems i s the main e f f e c t on b i o p h y s i c a l systems aside from ground-water e f f e c t s . While not u s u a l l y considered s i g n i f i c a n t , the excavation of the hole and the trenches of the t i l e f i e l d w i l l u s u a l l y require removal of surface vegetation which, i n combination with the disturbance of the s o i l * i t s e l f by machinery w i l l probably r e s u l t In increased runoff of water and s o i l erosion. The seriousness of these e f f e c t s w i l l depend on surface vege-t a t i o n and slope. Gravity sewers. The major land use e f f e c t of sewers i s opposite to. that of systems which use leach f i e l d s — a higher l o t density i s required i n order that the i n s t a l l a t i o n be economical. This requirement i n .-' Panorama Ridge West i s i n c o n f l i c t with the d e s i r e of current residents to r e t a i n the low density, r u r a l character of the area. Economies of scale i n sewer i n s t a l l a t i o n a l s o tend to r e s u l t i n s u b d i v i s i o n and sewering of r e l -a t i v e l y large areas, i r r e s p e c t i v e of the demand f o r the number of l o t s thereby provided, a p o s s i b i l i t y of which e x i s t s i n t h i s area[11]• And to the extent that economic considerations r e s u l t i n r e l a t i v e l y uniform l o t s i z e and shape and unimaginative subdivision design, the s u b d i v i s i o n may not be Septic tanks may be cast i n place i f space l i m i t a t i o n s preclude the use of a truck to bring i n a pre-cast tank; thus damage to s o i l and vegetation i s l o c a l i z e d i n the v i c i n i t y of the p i t and trenches. 59 . adapted to the t e r r a i n . This i s of p a r t i c u l a r concern i n the steeply sloping parts of the Ridge, where i t w i l l be necessary to match the pattern and design of l o t s to the landform i n order to minimize deleterious impacts of development. Unfortunately, the tendency a l l too often i s to impose on the landscape a sewer design that i s based only on engineering/economic considerations. Thus sewering i n Panorama Ridge could r e s u l t i n the l o s s of considerable tree cover i n addition to that caused by house construction. Coupled with increased problems of s o i l i n s t a b i l i t y and drainage as a r e s u l t of construc-t i o n a c t i v i t i e s , t h i s loss of vegetation cover w i l l lead to increased runoff and erosion. In f a c t , increased density has a two-fold e f f e c t on the movement of water i n the area. There i s the above-mentioned e f f e c t r e s u l t i n g from con-s t r u c t i o n a c t i v i t i e s and there i s the e f f e c t of the houses and the roads themselves i n reducing the absorptive capacity of the land. Development on the uplands i n other nearby areas has already r e s u l t e d i n increased f l o o d i n g of farmland i n the Surrey lowlands, and increasing the density of residen-t i a l use i n Panorama Ridge West, p a r t i c u l a r l y i f c a r r i e d out i n disregard for the t e r r a i n , w i l l aggravate the problem. r Composting t o i l e t s . The one and only e f f e c t on land use of composting t o i l e t s i s the complete removal of p h y s i c a l and econ-omic influences of sewage systems on the density and l o c a t i o n of r e s i d e n t i a l development on the Ridge. As f o r e f f e c t s on b i o p h y s i c a l systems, the p h y s i c a l e f f e c t s of i n s t a l l -a t i o n w i l l be l i m i t e d to those current residents of the area who choose to replace t h e i r s e p t i c tank/leach f i e l d system with a composting t o i l e t . . I f the t o i l e t i s one of the small types, the e f f e c t s w i l l be s i m i l a r to the e f f e c t s described for Bridgeview. If the i n s t a l l a t i o n of one of the large 60 i s p o s s i b l e , the e f f e c t s w i l l include a l t e r a t i o n s to the f l o o r as w e l l , and perhaps a w a l l . (c) Monetary and energy costs Septic tank/leach f i e l d . According to one resident[43] and to firms which i n s t a l l these systems, a t y p i c a l cost of t h i s system i n t h i s area i s about $1,500, assuming a pre-cast tank. I f the tank must be poured i n place, extra labour costs w i l l increase the i n s t a l l e d cost by about $400. There i s an energy cost of operation only i f s e p t i c tank e f f l u e n t must be pumped to a drainage f i e l d above the tank. There are al s o the energy costs of machinery uscid i n the i n s t a l l a t i o n and of the truck which p e r i o d i c a l l y pumps out the tank, but these have not been q u a n t i f i e d . Batch treatment/leach f i e l d . As i n Bridgeview, the source f o r the f i g u r e s • i n Table VIII i s NPS. The cost f i g u r e s are the same as w e l l , except for the leach f i e l d , which i s the usual method of e f f l u e n t disposal f o r t h i s system. The t o t a l cost i s an estimate based on i n s t a l l a t i o n of s i m i l a r systems across the province. TABLE VIII: UNIT COST OF PACKAGE TREATMENT - PANORAMA RIDGE WEST (Dollars) Treatment plant, i n s t a l l e d 2,900 Leach f i e l d , i n s t a l l e d 600 Less 20% volume discount 700 TOTAL. INSTALLED COST 2,800 Annual operating costs - maintenance a 144 - water (paid by Surrey) 3 - energy 141 TOTAL ANNUAL OPERATING COST 288 NOTE: Includes mandatory service check and replacement of both pumps once every f i v e years; i t does not make allowance f o r breakdown s e r v i c i n g . 61 Sanitary sewers. Since there are not yet any sewered areas i n Panorama Ridge West, i t was not possible to obtain a c t u a l costs of t h i s system. It was necessary instead to use the preliminary estimates of costs from the proposal to subdivide about 80 acres i n the northwestern portion of the Ridge, mentioned on page 45 and located as shown on Map 3. The proposed subdivision plan i s given as Figure 2; i t i s not a c t u a l l y the same as the one presented to Council, but i t i s the basis f o r the cost estimates shown i n Table IX. The assumption i s that the cost f i g u r e s f o r t h i s subdivision are representative of costs i n those areas of Panorama Ridge which share s i m i l a r topography and s o i l conditions. Cost estimates were also obtained .for i n d i v i d u a l components of sewer systems, and these were used to c a l c u l a t e costs for a range of l o t d e n s i t i e s . Figure 3 shows an a l t e r n a t i v e subdivision concept, suggested by A.. Cowie of EIKOS Planning and Design Group[11], which would reduce the l o s s of trees by c l u s t e r i n g 5 - l o t s within two-acre parcels along secondary roads. If the units were marketed under the Strata T i t l e Act, curbs and gutters could be eliminated and width of roads reduced, thereby reducing the amount of land that i s hard-surfaced. To determine the e f f e c t of t h i s r a d i c a l change i n subdivision design on the cost of sewering, i t was also costed using the same component costs as for the previous set of c a l c u l a t i o n s . Cost c a l c u l a t i o n s are given i n Appendix F, and the r e s u l t s summarized i n Table IX. The unit cost of providing sewer service to the c l u s t e r e d subdivision i s of some i n t e r e s t . The unit cost of $3,505 i s already higher than might be expected f o r a standard sub d i v i s i o n at the same density ( i n t e r p o l a t i n g the e s s e n t i a l l y l i n e a r r e l a t i o n s h i p between density and u n i t cost evident i n the f i r s t three columns of Table IX, the cost of a standard subdivision at 2.5 gross l o t s / a c r e i s about $3,350). Moreover, t h i s u n i t cost does not 62 J V J L i i i i r r r r I I 11 I I I I ' ' ' I I l i - l - l J I J.-L I I I I I I 'I 1 58 AVE ( N ° 10 HWY) NOTE: ALL SANITARY SEWERS ARE 8'V EXCEPT ON 120 ST. WHICH WILL BE 14"/! sewer l i n e manhole 53 AVE. A P L I N 8 M A R T I N . E N G I N E E R I N G LTD  E N G I N E E R S " P L A N N E R S a S U R V E Y O R S l I I .1 T T T l S A N I T A R Y S E W E R S SOLE.' I = 400' FIGURE 2: SUBDIVISION PLAN AND SEWER DESIGN. Very s i m i l a r to that presented to Council «e-— Secondary Road FIGURE 3: ALTERNATIVE SUBDIVISION DESIGN TWO-ACRE, FIVE-UNIT CLUSTER SCALE: 1" = 50' 64 TABLE IX: SANITARY SEWER COSTS - PANORAMA RIDGE WEST (Dollars a ) b DENSITY (gross l o t s / a c r e ) : 66.5 ACRES TWO-ACRE CLUSTER NATURE OF COST 2 . 0 C (133 l o t s ) 2.3 (F ig 2 ) d (152 l o t s ) 2.7 d (180 l o t s ) 2.5 (F ig 3) (5 l o t s ) A . DEVELOPER'S COST - O f f - s i t e sewers (8"0 & 14"0) - On-s i te sewers - 8"0 l a t e r a l s - 42"0 manholes - pressure tests 135,400 186,297 44,213 4,590 135,400 186,297 44,213 4,590 135,400 186,297 44,213 4,590 f 9,166 3,753 405 SUBTOTAL (DEVELOPER) 370,500 e 370,500 e 370,500 e 13,324 B. BUILDER'S COST - 4"0 to house - i nspec t ion chambers - plumbing and t o i l e t f i x tu re 53,865 13,300 39,900 61,560 15,200 45,600 72,900 18,000 54,000 590 500 1,500 SUBTOTAL (BUILDER) 107,065 122,360 144,900 2,590 - +10% contingency 47,757 49,286 51,540 1,591 TOTAL INSTALLED COST 525,322 542,146 566,940 17,505 UNIT COST 3,950 3,567 3,150 3,505 C . ANNUAL OPERATING COST - Water (paid by Surrey) 399 456 540 15 NOTES: kJanuary 1977 p r i c e s , based on cons t ruc t ion index Includes mater ia ls and labour c ^ Current zoning Proposed .density Assumes v a r i a t i o n i n density i s not great enough to requ i re changes j i n the sewer l i n e conf igura t ion shown in Figure 2 Determination of o f f - s i t e costs would require designing the whole s u b d i v i s i o n , not jus t one c l u s t e r include o f f - s i t e sewer costs, and i s therefore understated to a s i g n i f i c a n t , i f uncertain, degree. This i n d i c a t e s that although sewer systems can be • designed to adapt to the t e r r a i n and to minimize environmental d i s r u p t i o n , they may w e l l be more expensive as a r e s u l t . Composting t o i l e t s . The major d i f f e r e n c e i n the cost of t h i s system i n Panorama Ridge compared to Bridgeview i s that i n Pan-orama Ridge, s o i l conditions permit the use of a less-expensive greywater sub-system. It consists of a simple, pre-treatment f i l t e r , s i m i l a r to the one shown i n Appendix D, with the r e s u l t i n g e f f l u e n t being recycled f o r 65 domestic uses such as clothes washing and lawn/garden watering.* Any sur-plus could be discharged to a shallow r a i s e d seepage bed. The estimated cost of such a system i s about $300, with i n s t a l l a t i o n cost of about $50. I t must be pointed out here, though, that t h i s d i s p o s a l stategy w i l l require s p e c i a l approval from the l o c a l Health Inspector. In addition to a cheaper greywater sub-system, the i n s t a l l a t i o n cost of the t o i l e t has been reduced somewhat for new houses, since the house can be designed and b u i l t around the t o i l e t . The f i g u r e i s also a "guesstimate", since the labour involved i s spread over a period of time and would have to be separated from the labour involved i n b u i l d i n g that p o r t i o n or portions of the house. The estimate of costs i s presented i n Table X: TABLE X: UNIT COSTS OF COMPOSTING TOILETS - PANORAMA RIDGE WEST a (Dollars) CLIVUS-MULTRUM HUMUS-TOILET T o i l e t sub-system ^  1,850 c 790 - i n s t a l l a t i o n 100 75 Greywater sub-system 300 300 - i n s t a l l a t i o n 50 50 TOTAL INSTALLED COST 2,300 1,215 Annual energy cost 4 8 NOTES: fNew houses only FOB Vancouver, not FOB j o b - s i t e ^1976 p r i c e for 4-7 person capacity tank; standard tank i s $150 l e s s 1977 p r i c e f o r model H-10, incl u d i n g a 20% volume discount If there i s r e c y c l i n g of the water, then the cost of the t o t a l system must be increased to ac-ount for the addit i o n of extra p i p i n g and pumps; no estimate of t h i s cost was attempted. 66 Normalized comparison. Since the cost of the composting t o i l e t system (and the costs of the s e p t i c tank and batch treatment systems as well) i s independent of l o t density, an obvious question to ask i s , "At what density w i l l g r a v i t y sewers be economically competitive with composting t o i l e t s ? " . The c a l c u l a t i o n s are c a r r i e d out i n Appendix F, and the r e s u l t s are that gravity sewers are competitive with Clivus-Multrums at 4.3 gross l o t s per acre, and with Humus-Toilet at 18.6 gross l o t s per acre. To put these f i g u r e s into context, a density of 4.3 gross l o t s / a c r e i s approximately the density of a t y p i c a l urban, singles-family r e s i d e n t i a l area with 60'xl20' l o t s i z e s . A density of 18.6 gross l o t s / a c r e , however, i s absurd and i n e f f e c t implies a q u a l i t a t i v e jump to multiple-family dwellings. (d) Summary ana l y s i s In Panorama Ridge West, the composting t o i l e t system was compared to septi c tank, package treatment and g r a v i t y sewer systems. A l l four systems a f f e c t land use i n the area. Septic tank, and to a l e s s e r extent, package treatment systems generally impose an upper l i m i t on s u b d i v i s i o n density, above which there i s danger of groundwater contamination. The g r a v i t y sewer system imposes a lower l i m i t on density, below which sewering i s not economically f e a s i b l e . Septic tank and package treatment systems w i l l i n a d d i t i o n be subject to further r e s t r i c t i o n s i n p a r t i c u l a r areas where drainage and/or slope factors are unfavourable. In contrast, the composting t o i l e t system imposes no r e s t r i c t i o n s on the density, pattern or l o c a t i o n of subdivisions. There i s a s i m i l a r contrast between composting t o i l e t s and the other three systems i n regard to e f f e c t s on b i o p h y s i c a l systems. A l l three require, to a greater or l e s s e r extent, s o i l disturbance and tree/vegetation 67 removal, and consequently w i l l cause increased s o i l i n s t a b i l i t y and erosion, e s p e c i a l l y on sloping t e r r a i n . In ad d i t i o n , the higher density and lower 'permeability' of sewered subdivisions w i l l r e s u l t i n increased surface runoff and increased flooding i n the lowlands, while sub-surface movement of e f f l u e n t might be a problem with s e p t i c tank drainage f i e l d s i n some areas. Composting t o i l e t s , on the other hand, aside from minor a l t e r a t i o n s to e x i s t i n g houses, w i l l have a b e n e f i c i a l e f f e c t on s o i l f e r t i l i t y and moisture r e t e n t i o n , from using the humus and the nutrients i n greywater as s o i l amendments. With respect to costs, a summary comparison of a l l four systems i n Panorama Ridge West i s presented i n Table XI, based on a coiiiiu:«7i l o t density of 2.7 gross l o t s / a c r e . TABLE XI: TOTAL AND UNIT COSTS OF ALTERNATIVE SEWAGE SYSTEMS - PANORAMA RIDGE WEST SEWAGE SYSTEM TOTAL SYSTEM COST COST PER HOUSEHOLD INSTALLEr COST ANNUAL OPERATING COST INSTALL-ED COST ANNUAL OPERATING COST MONETARY (•$) ENERGY (kwh) MONETARY ($) ENERGY (kwh) MAINTEN-ANCE wATER ENERGY TOTAL MAINT. tfATER ENERGY TOTAL SEPTIC TANK AND LEACH FIELD 270,000 7,200 540 7,740 1,500 40 3 ? 43 ? PACKAGE TREATMENT 514,000 25,920 540 25,380 1 51,840 ; 558,540 2,800 144 3 14-1 : 288 3,103 CLIVUS-MULTRUM HUMUS-TOILET 414,000 - - 720 720 16,380 2,300 - - 4 4 91 218,700 - - 1,440 1,440 32,760 1,215 - 8 8 182 SANITARY SEWER 566,940 - 540 - 540 - 3,150 - 3 - 3 -68 Although a composting t o i l e t system i s again considerably l e s s expensive than the other systems, the ben e f i t s are not as uniform as i n Bridgeview. For example, septi c tank and gravity sewer systems apparently require no energy i n operation, at l e a s t within the study area boundary. And the i n i t i a l i n s t a l l e d cost of the se p t i c tank system i s $800 l e s s than the i n s t a l l e d cost of the Clivus-Multrum system, although a s i m p l i f i e d c a c u l a t i o n of operating costs over time i n d i c a t e s that the advantage may not be s i g n i f i c a n t . Assuming f o r the moment that annual operating costs f o r the s e p t i c tank system w i l l remain constant at $43, the d i f f e r e n c e between t h i s f i g u r e and the annual operating cost f o r the Clivus system ($4) w i l l , make up the dif f e r e n c e i n i n s t a l l e d cost i n about twenty years. But i s i t reasonable to expect, on the strength of the record of se p t i c tank systems i n general, that there w i l l be no major repa i r s required to the t i l e f i e l d , say, during a twenty-year period? And although the cost of water i s very low, i t i s based on the 'wholesale'rate which the Greater Vancouver Water D i s t r i c t charges Surrey, and t h i s rate i s lower than an i n d i v i d u a l household would pay. Is i t reasonable to expect the p r i c e of water to remain constant over the next twenty years? F i n a l l y , perhaps even the di f f e r e n c e In the i n s t a l l e d cost i s not as great as i t appears. One of the main reasons f o r the high cost of the Clivus-Multrum i s the low volume of production, which suggests the p o s s i b i l i t y of a volume discount f o r large orders of i t as w e l l as f o r the Humus-Toilet. The conclusion i s l e f t to the reader. 69 III.D CONCLUSION This chapter has shown that i n at l e a s t two markedly d i f f e r e n t r e s i d e n t i a l areas, the composting t o i l e t sewage system i s indeed a f e a s i b l e a l t e r n a t i v e to more conventional sewage systems. While the importance of the b e n e f i t s r e l a t i n g to land use and b i o p h y s i c a l systems may vary from one community to the next, i t i s l i k e l y that the b e n e f i t s r e l a t i n g to i n s t a l l a t i o n and operation costs are more generally r e a l i z a b l e . And here i t i s w e l l to r e c a l l that the i n s t a l l a t i o n , maintenance and energy costs of sewage treatment plants and trunk sewers were not included i n the comparison, as t-hey properly should be. It i s conceivable that i n some communities, the f i n a n c i a l b e n e f i t s of the composting t o i l e t system might be marginal, non-existent or even negative. The question must then be asked of the people of those communities, "What value should be placed on the conservation of water and n u t r i e n t s , on the elimination of water p o l l u t i o n and the r i s k of disease transmission, and on the avoidance of other problems associated with conventional sewage systems?" 70 CHAPTER IV PLANNING IMPLICATIONS IV.A INTRODUCTION Chapter II has described and evaluated the composting t o i l e t sewage system and found i t to be a s u i t a b l e system for the treatment and d i s p o s a l of human excreta. In p a r t i c u l a r , i t appears to be a very appropriate sewage system for a Conserver Society Chapter I I I has compared the composting t o i l e t system to other, more or l e s s conventional systems i n two s p e c i f i c communities and found not only i s i t a f e a s i b l e a l t e r n a t i v e to these systems, i t i s a preferable a l t e r n a t i v e as w e l l , since i t greatly reduces the environmental and f i n a n c i a l impacts of sewage treatment and d i s p o s a l . In e f f e c t , these two chapters have set the stage f o r the present chap-ter by showing that the exploration of planning implications of composting t o i l e t s i s based not on wishful thinking but on r e a l i t y . Some of the implications of composting t o i l e t s have been stated i m p l i c i t l y , a l b e i t i n a narrow context, i n the l a s t chapter. The most impor-tant i m p l i c a t i o n , e c o l o g i c a l i n nature, has been stressed several t i m e s — the r e c y c l i n g of human excreta back to the s o i l and the reduction of water waste and p o l l u t i o n brings a human society into c l o s e r harmony with i t s l i f e -support systems. The enhanced psychological well-being that members of that soci e t y may enjoy as a consequence of that harmony should hot be taken l i g h t l y . Happily there are b e n e f i c i a l implications of a more s u b s t a n t i a l nature as w e l l , for communities and planners ( i n the broadest sense of the w ord— one who plans). In a sense, many of these implications are obvious, but they s t i l l need to be stated i n a way that brings them in t o the p u b l i c conscious-ness. The purpose of t h i s chapter, then, i s to e x p l i c i t l y state the planning 71 implications and i n d i c a t e the range of s i t u a t i o n s i n which composting t o i l e t s may be used. The underlying hope i s that people/communities may recognize t h e i r own sewage problems i n one or more of these s i t u a t i o n s and be moved to consider composting t o i l e t s as part of the s o l u t i o n . IV.B THE IMPLICATIONS , The following implications are categorized under three headings: Land Use, Cost and F l e x i b i l i t y . The categories are obviously not mutually e x c l u s i v e — both land use and f l e x i b i l i t y can be very dependent oh how much money Is a v a i l a b l e — but suggest that the heading under which each i m p l i c a t i o n i s described i s the a r t a i n which that i m p l i c a t i o n has i t s dominant e f f e c t . I n t e r r e l a t i o n s h i p s w i l l be obvious i n the context or w i l l be stated e x p l i c i t l y . B . l Land Use (a) R e s i d e n t i a l l o t s i z e i n suburban/rural areas need no longer be influenced  by the drainage area requirements of s e p t i c tank systems or by the economic  f e a s i b i l i t y requirements of sanitary sewer systems. Thus increased density can be planned f o r without the necessity of also paying f o r sewer l i n e s and pos s i b l y treatment plants i n order to avoid groundwater contamination from septic tank t i l e f i e l d s . Panorama Ridge i s an example of such a s i t u a t i o n . (b) R e s i d e n t i a l l o t l o c a t i o n need no longer be r e s t r i c t e d by surface and  sub-surface conditions. Thus r e s i d e n t i a l development can be permitted on land where topography, geology and/or drainage prevent the use (except p o s s i b l y at great expense) of both sewers and s e p t i c tanks. The steeply sloping p o r t i o n of Panorama Ridge i s an example. (c) R e s i d e n t i a l development can be permitted i n proximity to lakes and  streams without danger of pathogen contamination or eutrophication. F i r s t , there are those forms of r e s i d e n t i a l development that are very clos e to 72 water—houseboats and yachts, for example (a houseboat community has already been mentioned in Chapter II) On a larger scale, a good example is the Sons of Norway subdivision also mentioned in Chapter II, in which the residential use of lake-front land wi l l not adversely affect the quality or diversity of water-based rec-reation in the area. And of course, one area of the province in which composting toilets should be used is in the Okanagan, where indirect or direct discharge of residential/municipal sewage into Lake Okanagan is a large factor in the growth of water weeds that is causing so much concern in the region. The decision has been made to k i l l the weeds with herbicides, but in order for this controversial action to have more than a passing effect, the total program must include attacking the root of the problem as well as the symptoms, and i t is here that the composting toilet system could play a significant role. Just as in Bridgeview, however, the composting toilet system in such cases must include a greywater sub-system that does not let nutrients escape into the environment, regardless of the season. This last point is significant JjQTtorthern locations such as the Okanagan because infiltration systems are much less effective during the winter when the ground is frozen. Either the greywater sub-system must be so effective that i t discharges clean water, or there must be a minimum of discharge from the household, with almost complete recycling. Inany case, the cost of the total system wi l l be higher than usual. (d) Residential development can take place in areas without an adequate  water supply. Living in the Lower Mainland tends to make one forget that not a l l parts of British Columbia, not to mention the rest of the world, enjoy abundant water at low prices. As a result, the cost of water as part of the operating cost of water-borne systems in Tables VII and XI may seem ... 73 to be n e g l i g i b l e . However, the cost of water used i n f l u s h t o i l e t s a l l over the Lower Mainland i s a considerable sum and more important, the continuing a v a i l a b i l i t y of that water can no longer be taken f o r granted. We are enter-ing a period of c l i m a t i c v a r i a b i l i t y that w i l l have grave implications f o r -more than j u s t the supply of water to f l u s h away sewage, but the p o t e n t i a l d i s r u p t i o n i n that supply cannot be ignored, e i t h e r . B r i t i s h Columbia i s experiencing t h i s year an abnormally low snowpack i n the mountains which supply many communities with t h e i r water. What i f t h i s dry year should be followed by several more i n a row? Nor need t h i s i m p l i c a t i o n wait for drought conditions to make i t relevant. There are already areas where i t w i l l be welcomed, incl u d i n g areas not served with piped water and communities i n the North, situated on rock, tundra or permafrost, with water at a premium. As i n d i c a t e d i n Chapter I I , composting t o i l e t s have a double impact on the amount of water used by a household. In the f i r s t place, water use i s reduced by about 50% r i g h t away by e l i m i n a t i n g the f l u s h t o i l e t . And i n the second place, separating t o i l e t wastes and greywater makes i t easier to tre a t greywater to a s u f f i c i e n t l y high q u a l i t y that i t can be recycled w i t h i n the household f o r non-potable uses. I t i s l i k e l y that household water con-sumption could be reduced to- a small f r a c t i o n of the present quantity, and that the r e s u l t a n t savings would more than cover the cost of the extra plumbing that would be required i n most cases. B.2 Cost (a) The cost of providing a dependable, environmentally-safe sewage system  can be reduced. The magnitude of the reduction w i l l vary considerably from one community to another, depending on environmental f a c t o r s , density and proximity to e x i s t i n g sewer systems, f o r example. I t i s l i k e l y that the 74 savings w i l l be least i n communities or neighbourhoods within an urban area, although the examples of Bridgeview and Panorama Ridge show that even in this case, the savings may be considerable. The reductions in these areas, however, are nominal in comparison to communities in Newfoundland, where i t can cost from $6,000 - $22,000 per lot to provide sewer service, depending on density, location and terrain/geology[19]. Another example closer to this part of the country might be some of the Gulf Islands, on which single dwellings or clusters of houses are scattered a l l over the island, often separated by heights of land, and although density may have increased i n some areas to the point where septic tanks are no longer acceptable, the irregular d i s t r i -bution and the relatively small size of these densely popualated areas makes sewering highly impractical/expensive, i f i t is not already so as a result of geographical or geological factors. Perhaps the most dramatic cost reductions w i l l occur i n communities where some or a l l of the composting to i l e t s can be constructed for a mater-i a l s cost of about one hundred dollars or less per t o i l e t [see Section II.A.6 and Appendix C]. The total cost would depend on which of several means of providi.^ che necessary labour were adopted. Using unpaid labour, each house-hold could build i t s own t o i l e t , or groups of households might pool their resources and build accordingly. Methods involving paid labour might include anything from a group funded by a program like Local Initiative Projects, to a collective charging a modest fee, to a new or existing local firm operating along more conventional lines. In any case, the latter methods would create jobs i n the community as well as t o i l e t s , and might even lead to something more permanent once the community's toilets were bu i l t . This implication also has important benefits for a strategy of decentralizing populations by encouraging people to li v e and work in smaller-sized communities. An influx of people to small communities w i l l require an 75 upgrading of s e r v i c e s , e s p e c i a l l y sewage servi c e s , for which most i f not a l l communities would f i n d i t d i f f i c u l t to pay without f i n a n c i a l assistance from the l e v e l ( s ) of government which i n i t i a t e d the d e c e n t r a l i z a t i o n pro-gram. Composting t o i l e t systems would reduce the f i n a n c i a l impact both on the community and on the government(s). Whether there i s a d e c e n t r a l i z a t i o n p o l i c y or not, of course, senior governments these days are i n e v i t a b l y involved i n financing sewage programs because of t h e i r t y p i c a l l y high cost. Under Part VIII of the National Housing Act, f o r instance, m u n i c i p a l i t i e s can obtain loans f o r up to two-thirds of the e l i g i b l e costs of a sewage project through Central Mortgage and Housing Corporation[6]. An examination of these costs shows that the cost savings e f f e c t e d by i n s t a l l i n g composting t o i l e t s include more than j u s t the costs of construction emphasized i n Chapter I I I . For example, land purchase and c a r r y i n g charges; i n t e r e s t payments, depending on how protracted i s the construction; design and supervision costs; l e g a l s e r v i c e s ; and i n t e r i m financing are e l i g i b l e costs that would be eliminated or greatly reduced through i n s t a l l a t i o n of composting t o i l e t s . CMHC's annual budget f o r sewage programs i n t h i s region i s about $30 m i l l i o n i n loans, representing $45 m i l l i o n i n a c t u a l work, with one of the main l i m i t a t i o n s on how how t h i s budget can go i s the allowable indebtedness which m u n i c i p a l i t i e s can incur[57]. How much of t h i s money could be freed f o r other p r o j e c t s , or not c o l l e c t e d from the taxpayers i n the f i r s t place, by the use of composting t o i l e t systems? (b) The incidence of d i r e c t sewage system costs w i l l s h i f t away from  m u n i c i p a l i t i e s toward i n d i v i d u a l households. This i m p l i c a t i o n flows out of the above disc u s s i o n on financing, but i s also a consequence of the f a c t that composting t o i l e t s require i n d i v i d u a l s to assume greater r e s p o n s i b i l i t y , i n c l u d i n g f i n a n c i a l r e s p o n s i b i l i t y , f or proper di s p o s a l of t h e i r wastes. 76 In so doing, they must bear the costs d i r e c t l y , rather than i n d i r e c t l y through taxes or perhaps not at a l l i f s o - c a l l e d ' e x t e r n a l i t i e s ' are not included i n the f i n a l b i l l . The s i t u a t i o n i s s i m i l a r to the promotion of energy conservation by r e q u i r i n g higher i n s u l a t i o n standards, and while i t i s c e r t a i n l y d e s i r a b l e to b r i n g these costs into the open, as i t were, a s h i f t i n g of the sewage subsidy from m u n i c i p a l i t i e s to households i s also d e s i r a b l e , i n the cases where f o r equitable reasons, subsidies are warranted. At the moment, however, a condition f o r sewage financing through CMHC i s : the c o n t r o l and operation of the r e s u l t i n g system by the m u n i c i p a l i t y [ 5 7 ] . This i s c l e a r l y inappropriate f o r the composting t o i l e t system and although a l t e r n a t e forms of financing might be p o s s i b l e under a d i f f e r e n t part of the National Housing Act, i t would make more sense to amend the e x i s t i n g r e g u l -ations and/or the Act i t s e l f to provide financing for i n d i v i d u a l households. (c) Municipal garbage c o l l e c t i o n frequency and therefore cost could be  g r e a t l y reduced. Garbage which s i t s i n the s t r e e t f o r more than a week while awaiting c o l l e c t i o n poses an a e s t h e t i c as w e l l as a health hazard. With a composting t o i l e t , though, a l l organic scraps could be placed i n the t o i l e t , and the remainder of the garbage could e a s i l y be kept i n the basement or i n appropriate containers outside f o r at l e a s t a month (the bulk of s o l i d wastes i s d r a s t i c a l l y reduced by f l a t t e n i n g metal and cardboard c o n t a i n e r s ) . Furthermore, a household that has taken the f i r s t step of handling the organic f r a c t i o n separately could be e a s i l y persuaded to separate the paper, p l a s t i c , glass and metals as w e l l . The m u n i c i p a l i t y would then be w e l l on the way to f u l l r e c y c l i n g of s o l i d garbage, another obvious c h a r a c t e r i s t i c of a Conserver Society. B.3 F l e x i b i l i t y To a considerable extent, t h i s category includes i m p l i c a t i o n s that 7 7 r e - s t a t e or synthesize implications i n the f i r s t two categories. (a) Increased f l e x i b i l i t y i n the design and l o c a t i o n of r e s i d e n t i a l  development. This i m p l i c a t i o n combines land use and cost implications d i s -cussed e a r l i e r , and has already been mentioned i n the context of Panorama Ridge i n Sections III.C.2(b) and (d): density and pattern of r e s i d e n t i a l s u bdivisions can respond to s o c i a l and e c o l o g i c a l considerations as w e l l as to economic and engineering considerations. For example, although the environmentally-appropriate c l u s t e r s u b d i v i s i o n design f o r Panorama Ridge c a r r i e d a f i n a c i a l penalty i n comparison with a conventional design when serviced with g r a v i t y sewers, there would be no such problem i f the compost-in g t o i l e t system were i n s t a l l e d . And i n s i t u a t i o n s , e s p e c i a l l y i n northern l a t i t u d e s , where land i s not l i m i t e d and c u l t u r a l or s o c i a l f a c t o r s require low or i r r e g u l a r desnsity of dwellings, i t w i l l not be necessary to force people i n t o a settlement pattern t y p i c a l of urban neighbourhoods i n mid-l a t i t u d e regions because of the economics of sewer i n s t a l l a t i o n [ s e e appendix A]. This i m p l i c a t i o n also has great s i g n i f i c a n c e when applied to the prob-lem of conserving a g r i c u l t u r a l land while at the same time providing new land to house a growing population. One of the major reasons f o r urban encroachment on a g r i c u l t u r a l land i s the ease of s e r v i c i n g such land, and while i t i s easy to say that new development should take place on land that i s not s u i t a b l e f o r farming, much of t h i s land, e s p e c i a l l y i n B r i t i s h Columbia, i s rocky and/or steeply s l o p i n g . Not only do these f a c t o r s greatly increase the cost of providing sewer s e r v i c e , but the construction a c t i v i t i e s themselves may s e r i o u s l y disrupt s o i l s and surface vegetation and lead to increased runoff and erosion. Composting t o i l e t systems, i n conjunction with t e r r a i n s e n s i t i v e municipal s e r v i c i n g standards (eg., fewer roads), would permit moderately dense development on s i t e s such as mountain slopes with the l e a s t disturbance of the the p h y s i c a l environment, and at a lower cost. 78 In s i t u a t i o n s where housing development must be located on a g r i c u l -t u r a l land, the developer could be required to design a number of small, densely populated enclaves, surrounded by farmland. Conventional sewering of t h i s pattern would l i k e l y be very expensive, but composting t o i l e t systems could accommodate i t e a s i l y . (b) Increased f l e x i b i l i t y i n the phasing of development over time and space. Ah example of r i g i d time phasing i s the necessity i n Bridgeview of beginning and completing construction of the vacuum sewer system during the summer months when the water table i s s u f f i c i e n t l y low (In other parts of the coun-t r y , a s i m i l a r r e s t r i c t i o n might be that the ground i s frozen f o r a l l but a. few months of the year). However, a number of f a c t o r s could "close the window", i c l u d i n g delays i n securing right-of-way permission from property owners; s t r i k e s i n the construction or r e l a t e d i n d i s t r y ; or an abnormally wet spring and summer (to compensate f o r an abnormally dry winter?) so that the water t a b l e remains at or near the surface. Any one of these f a c t o r s would involve delays which, i n these days of rapid i n f l a t i o n , could add even furth e r to the costs. In contrast, composting t o i l e t s can be i n s t a l l e d i n any season, at whatever rate i s d e s i r a b l e or p o s s i b l e , and by the residents themselves i f need be. Panorama Ridge provides an example of r i g i d scheduling i n space as w e l l as time. The proposed s u b d i v i s i o n would contain a c l a s s of expensive houses which may already be i n over-supply i n the Lower Mainland[11], and i n l i g h t of the f a c t that none of the houses would have much of a view, i t i s more than l i k e l y that 180- l o t s w i l l take a long time to s e l l , with the land having been cleared and the developer bearing the c a r r y i n g charges. I t appears to make much more sense to subdivide and service ten or twenty (or however many the market would bear) l o t s at a time, but t h i s i s hardly 79 the most economical way to program sewer construction. With composting t o i l e t s as the sewage system, however, there would be no problem at a l l with t h i s stategy. (c) Increased f l e x i b i l i t y i n financing arrangements. As mentioned e a r l i e r , -i t i s v i r t u a l l y c e r t a i n that senior l e v e l s of government must subsidize sewer programs, to a greater or l e s s e r extent depending on the pro s p e r i t y of the community and on ph y s i c a l f a c t o r s which determine the cost of sewer-ing. This f a c t of l i f e does not, however, guarantee that every community w i l l receive as much money as i t wants, when i t needs i t . There i s often a l i m i t e d amount of money to be d i s t r i b u t e d , many e n t i t i e s competing f o r i t and the f i n a l d e c i s i o n i s very dependent on p o l i t i c a l f a c t o r s . Even when governments are w i l l i n g and committed to helping a community with i t s ' s p e c i a l ' sewage problems, there can be delays before the financing formula i s approved (or s p e c i a l l e g i s l a t i o n passed) whereby the t y p i c a l l y large amount of c a p i t a l i s made a v a i l a b l e to the community. And since governments are often the only source of these large amounts of money, m u n i c i p a l i t i e s have l i t t l e recourse but to c u l t i v a t e patience. In contrast, the i n s t a l l a t i o n of composting t o i l e t s need not i n theory require that the mun i c i p a l i t y borrow or otherwise acquire large amounts of money at once. Indeed, as pointed out e a r l i e r , i n many communities a large p o r t i o n of the households w i l l be able to a f f o r d the t o i l e t s themselves, with some form of subsidy required only f o r low income households. But assuming that the municipality took r e s p o n s i b i l i t y f o r financing the i n s t a l l -a t i o n i t s e l f , the program could be phased s o l e l y according to the state of municipal finances and to the var i e d need f o r sewage service i n the commun-i t y . Perhaps the s e p t i c tanks i n a well-drained segment of the community could function s a t i s f a c t o r i l y f o r a number of years more, whereas another area must convert to an alt e r n a t e system and the sooner the bet t e r . In la r g e r 80 communities, there might already be sewers i n s t a l l e d , or approved f o r financ i n g , to service the c e n t r a l , high-density core, with only o u t l y i n g areas and new subdivisions i n need of a sewage system. In any case, the beginning and the pace of the i n s t a l l a t i o n would be much more under the c o n t r o l of the municipality and responsive to i t s needs. (d) Perhaps a f i n a l i m p l i c a t i o n that ought to be mentioned i s one that i s a consequence of t h i s new-found f l e x i b i l i t y : Planners can no longer r e l y on the high cost of sewering as a reason for not permitting low density r e s i d e n t i a l  development or as a b a r r i e r to high density development. In other words, f l e x i b i l i t y works both ways. There are other reasons f o r large suburban or semi-rural l o t s beside the needs of s e p t i c tank systems, and composting t o i l e t s can be used to j u s t i f y urban sprawl as e a s i l y as they can be used to promote more compact development'. And there are le g i t i m a t e needs and pressures to increase the density of r u r a l , non-farm areas, i n s p i t e of the desires of current residents, i n order to ease the pressure on farmland fa r t h e r away from the c i t y that i s s t i l l v i a b l e . (Equivalently f o r the use of s e p t i c tank drainage f i e l d s as a 'planning t o o l ' , there may w e l l be other reasons why development should not be permitted too close to lakes and streams.) Planners and other municipal o f f i c i a l s must therefore l e a r n to be more a s s e r t i v e about what pattern of development i s d e s i r a b l e and to defend t h e i r p o s i t i o n with the good reasons which remain, rather than use the manipulative, double-edged but d u l l e d sword of sewage system cost/problems. They must a l s o r e a l i z e that the composting t o i l e t i s indeed a versa-t i l e t o o l . With i t , human settlements can be located v i r t u a l l y anywhere and designed along any pattern, without worrying about the const r a i n t s of the sewage system. I f t h i s rather sweeping statement can be j u s t i f i e d f o r new human 81 settlements, the general a p p l i c a b i l i t y of the composting t o i l e t system i s more open to question. The next section therefore attempts to define use-si t u a t i o n s i n which composting t o i l e t s could/should be i n s t a l l e d as the sewage system. IV.C POTENTIAL APPLICATIONS OF THE COMPOSTING TOILET SYSTEM Chapter I I discussed the s u i t a b i l i t y of the composting t o i l e t system i n terms of i t s performance. Chapter I I I discussed the f e a s i b i l i t y of the system i n two p a r t i c u l a r u s e - s i t u a t i o n s . And i n Section B of t h i s chapter, further use-situations were described or implied. The purpose of t h i s sec-t i o n i s to combine the concepts of s u i t a b i l i t y and f e a s i b i l i t y and develop a general structure which w i l l i l l u s t r a t e the p o t e n t i a l a p p l i c a t i o n s of the composting t o i l e t system. Although i t includes both s u i t a b i l i t y and f e a s i b i l i t y , the structure i s e s s e n t i a l l y conceived of as a s u i t a b i l i t y continuum. The r e s u l t s of Chapter I I I w i l l strongly i n d i c a t e which use-situations are l i k e l y to be f e a s i b l e , but a f i n a l determination w i l l require a s i t u a t i o n - s p e c i f i c anal-y s i s s i m i l a r to the one c a r r i e d out i n Section III.C The s u i t a b i l i t y continuum i s defined i n terms of v a r i a t i o n i n sc a l e of i n s t a l l a t i o n and i n density of settlement. Factors such as environmental impact, conservation of water and l i m i t a t i o n s r e l a t i n g to geology, t e r r a i n (for conventional systems) and design of e x i s t i n g communities and houses, have the e f f e c t of moving a p a r t i c u l a r u s e - s i t u a t i o n toward one or the other end of the continuum. At the ' h i g h ' s u i t a b i l i t y end of the continuum, there are minor or no r e s t r i c t i o n s on the use of composting t o i l e t s . At the 'low' end, there are major or many r e s t r i c t i o n s on t h e i r use. For convenience, the use-situations are described below under three 'ranges' of the continuum, i n order of decreasing s u i t a b i l i t y : s i n g l e i n s t a l l a t i o n / l o w density, small-82 scale community/medium density, and large urban area/high density. Single i n s t a l l a t i o n / l o w density. This range i s very near the high end of of the continuum. In terms of scale of i n s t a l l a t i o n i t includes: farmhouses; r e c r e a t i o n a l residences; i s o l a t e d dwellings or structures such as parks, r e s o r t s or s k i chalets; mobile dwell-ings, such as 'mobile'homes , houseboats or large r e c r e a t i o n a l v e h i c l e s . I t also includes temporary communities such as construction and logging camps, although these can be considered part of the next range as w e l l . The only conceivable r e s t r i c t i o n i s the p a r t i c u l a r l y severe combination of lack of e l e c t r i c a l power, cold climate and a b u i l d i n g design that requires i n s t a l l a t i o n of the t o i l e t i n an unheated space, and perhaps even t h i s i s not an absolute r e s t r i c t i o n . In terms of settlement density, composting t o i l e t systems are most appropriate f o r use i n r u r a l , r u r a l non-farm and low to medium density, seasonal r e c r e a t i o n a l areas. Small pockets of higher density r e s i d e n t i a l use are i n the t r a n s i t i o n zone bewteen t h i s range and the next. The only r e s t r i c -t i o n s would l i k e l y be s a t i s f a c t i o n with e x i s t i n g system, i n a b i l i t y to pay : or apprehension about the t o i l e t i t s e l f . Small-scale community/medium density. This range occupies the middle to upper p o r t i o n of the continuum, and the p o s i t i o n of use-situations w i t h i n i t may be strongly influenced by one or more of the factors noted i n the t h i r d paragraph of t h i s s e c t i o n . At the upper l e v e l s are v i l l a g e s and towns, us u a l l y served by s e p t i c tank systems, perhaps even with gravity sewers discharging d i r e c t l y to water bodies, but which cannot a f f o r d e i t h e r advanced sewer systems, i n c l u d i n g treatment f a c i l i t i e s , or the continuation of the e x i s t i n g s i t u a t i o n . Next are new subdivisions, i n c l u d i n g clustered designs, which are near urban areas served 83 by sewer systems but which cannot a f f o r d , or do not choose, to hook into that system. At the lower end of the range are outl y i n g subdivisions which need to upgrade t h e i r sewage system and f i n d themselves i n one of the follow-ing s i t u a t i o n s : a) sewer systems are i n place but are i n a c c e s s i b l e because of cost considerations; b) sewer systems are i n place but are already at or over design capacity; or c) sewer systems are i n place, have excess capacity, but discharge sewage in t o a rudimentary treatment f a c i l i t y and residents choose not to participate i n an environmentally-harmful system. Density e f f e c t s i n t h i s range are superimposed on the i n s t a l l a t i o n s c a l e and determine the r e l a t i v e p o s i t i o n of a p a r t i c u l a r u s e - s i t u a t i o n w i t h i n the range. For example, composting t o i l e t s may be more s u i t a b l e f o r a low density, e x i s t i n g subdivision than f o r a higher-density, new su b d i v i s i o n . R e s t r i c t i o n s on the use of composting t o i l e t s i n t h i s range may include those of the previous range, but are more l i k e l y to be r e l a t e d to economic f e a s i b i l i t y i n comparison with other systems, i n the rather u n l i k e l y event that economics i s the only relevant consideration. There do not appear to be any serious l i m i t a t i o n s on the use of composting t o i l e t s i n t h i s range. Large urban area/high density. This range occupies the lower h a l f of the continuum. Most large urban areas are w e l l sewered and the only s i t u a t i o n s i n which the use of composting t o i l e t s may be s u i t a b l e / f e a s i b l e are small, non-sewered neighbourhoods, e s p e c i a l l y with unusual p h y s i c a l r e s t r i c t i o n s , of which Bridgeview i s an example. There may also be i n d i v i d u a l households which e l e c t to convert from f l u s h to compost-ing t o i l e t s i n order to produce f e r t i l i z e r f o r household use. In general, however, i t w i l l be better to conserve the tremendous c a p i t a l investment represented by sewer systems, by making use of t h e i r a b i l i t y to concentrate the p o t e n t i a l f e r t i l i z e r and by improving the treatment process at the downstream end. 84 S i m i l a r l y , with e x i s t i n g high density, m u l t i p l e - u n i t r e s i d e n t i a l b u i l d i n g s , tbe conversion to composting t o i l e t s i s inappropriate. However, f o r new b u i l d i n g s , p a r t i c u l a r l y i n suburban and other unsewered areas or communities, a system such as the one described i n Section I I . B . 6 , i n v o l v i n g a combination of vacuum t o i l e t s and a large decomposition chamber, i s s u i t -able and probably f e a s i b l e . This type of need f o r a sewage system might also be met by other systems which follow the basic p r i n c i p l e of the composting t o i l e t — t h a t human body wastes are a resource that must be conserved and recyc l e d . Examples include the CANWELL system, also mentioned i n Chapter I I , and an anaerobic digestion tank which produces f e r t i l i z e r (or animal feed) and a combustible gas. Both of these systems should be integrated i n t o the t o t a l s e r v i c e s system of the b u i l d i n g since they are producers of water and energy. As i t turns out, the ' r e s t r i c t i o n s ' on the use of composting t o i l e t s i n t h i s range are not r e a l l y r e l a t e d to the t o i l e t s themselves. In the case of e x i s t i n g urban areas, i t i s bett e r to 'recycle' e x i s t i n g sewage systems, and i n the case of new, high density s i t u a t i o n s , i t i s here that the value and nted f o r a d i v e r s i t y of solutions i s most evident. 85 ' ' ' <• CHAPTER V CONCLUSION AND RECOMMENDATIONS V.A SUMMARY CONCLUSIONS Chapter I I concluded that the composting t o i l e t system i s a s u i t a b l e system f o r the disp o s a l and treatment of human body 'wastes': i t does not create a hazard e i t h e r to human health or to the p h y s i c a l environment; i t creates few, i f any, nuisance e f f e c t s and these are minor i n nature, l o c a l -i z e d i n extent and perhaps to be expected i n what i s s t i l l a r e l a t i v e l y new system; i t conserves and recycles the p h y s i c a l materials flowing through i t ; and i t does not require excessive use of energy or non-renewable resources, although the considerable v a r i a t i o n among types and makes of composting t o i l e t s i n t h i s regard means that some t o i l e t s are preferable to others. A question that was touched on but not answered i s whether or not the composting t o i l e t i s an acceptable sewage system i n l i g h t of the a t t i t u d e toward human body wastes held by many North Americans. The experience with these t o i l e t s to date suggests that t h i s question can be answered i n the a f f i r m a t i v e . However, i t could be argued that the only people who uave i n s t a l l e d composting t o i l e t s are people who are already h e a v i l y biased i n favour of the t o i l e t s , and are therefore not t y p i c a l of the general popul-a t i o n . I f t h i s be true, i t i s only another argument f o r the need, before i n s t a l l i n g composting t o i l e t s i n a community, to explain c a r e f u l l y to the residents of that community the nature of the system and the nature of t h e i r p a r t i c i p a t i o n i n i t . This should ensure the acceptance of the system and w i l l minimize the problems experienced i n the "break-in" period following i n s t a l l a t i o n . . Chapter I I I concluded that the composting t o i l e t system i s a f e a s i b l e 86 a l t e r n a t i v e to the more or l e s s conventional sewage systems i n use today, at l e a s t i n two areas. But although the extent of the comparison i s necess-a r i l y l i m i t e d , the two areas chosen are e i t h e r unfavourable to the compost-ing t o i l e t i t s e l f or are favourable to the a l t e r n a t i v e s . In s p i t e of t h i s , the composting t o i l e t system requires l e s s damage to b i o p h y s i c a l systems than do the a l t e r n a t i v e s f o r each area, and i n one area, removes a l l sewage system-related r e s t r i c t i o n s on the density, pattern and l o c a t i o n of r e s i d e n t i a l s u b d i v i s i o n s . Even more i n t e r e s t i n g , one of the composting t o i l e t systems costs considerably l e s s to i n s t a l l and maintain than any of the a l t e r n a t i v e systems, and while the other t o i l e t system costs l e s s than a l l but the se p t i c tank system, the l a t t e r system s u f f e r s i n the non-monetary comparison. And as mentioned s e v e r a l times throughout the chapter, cost comparisons i n v o l v i n g sewer systems contain a wide margin of e r r o r i n favour of the composting t o i l e t system as a r e s u l t of the exclusion of treatment cost and a large p o r t i o n of c o l l e c t i o n cost of the sewer system. I t i s l i k e l y that the d e s i r a b i l i t y of the composting t o i l e t system i n the two comparison areas can be generalized to many other s i t u a t i o n s . I t i s also l i k e l y that some communities may choose to make trad e - o f f s between monetary and non-monetary considerations when the composting t o i l e t system costs more than a conventional system. Nevertheless, the costs and be n e f i t s a t t r i b u t e d to composting t o i l e t systems are i n some part t h e o r e t i c a l and w i l l remain so u n t i l the t o i l e t s have a c t u a l l y been i n s t a l l e d i n one or more communities. Chapter IV, i t s legitimacy based on the proven s u i t a b i l i t y and feas-i b i l i t y of composting t o i l e t systems, i s i t s e l f a c o n c l u s i o n — t h a t there are r e a l i m p l i c a t i o n s i n the use of composting t o i l e t s . In p a r t i c u l a r , there 87 are land use impli c a t i o n s : the use of composting t o i l e t s g r eatly expands the type and amount of land on which human settlements can be located with-out unacceptable environmental cost. There are cost i m p l i c a t i o n s : the cost of municipal waste di s p o s a l services can be s i g n i f i c a n t l y reduced, by an amount depending on l o c a l conditions, and a wider range of communities can a f f o r d an e f f e c t i v e , environmentally-safe sewage system. And there are f l e x i b i l i t y i m p l i c a t i o n s : increased f l e x i b i l i t y i s gained i n the planning, financing and phasing over time and space of r e s i d e n t i a l subdivisions/sewage programs. The e s s e n t i a l i m p l i c a t i o n here i s that human settlements need no longer be planned around the obstacles imposed by sewage systems. Perhaps the most important implications have yet to be stated i m p l i c i t l y : The use of composting t o i l e t s increases the p a r t i c i p a t i o n of  i n d i v i d u a l s i n an important s o c i e t a l i n s t i t u t i o n . So often i n our indust-r i a l i z e d s o c i e t y , i n d i v i d u a l s are relegated to the r o l e of mere consumers of various s e r v i c e s , whether i t be the p r o v i s i o n of food or the e l i m i n a t i o n of waste. P a r t i c i p a t i o n i n these " p r o v i s i o n systems" i s often d i f f i c u l t because of tech n o l o g i c a l complexity and/or a high degree of c e n t r a l i z a t i o n , and thus we come to r e l y on the p r o v i s i o n of 'experts'. The composting t o i -l e t i s a modest beginning to achieving greater personal independence from experts. I t involves the user r i g h t from the s t a r t to the f i n i s h of the di s p o s a l of her/his own body wastes: i f need be, the system can be cons-tructed by the users from l o c a l l y a v a i l a b l e materials; i f purchased, the i n s t a l l a t i o n requirements are simple enough that most households could cope with them and, where t h i s i s not the case, the necessary s k i l l s w i l l be a v a i l a b l e w i t h i n the community, thus taking advantage of a time-honoured p r o v i s i o n system—neighbourliness; and once i n s t a l l e d , optimum performance of the system requires the conscious p a r t i c i p a t i o n of the users, and t h e i r c o n t r o l over the use of the end product i s v i r t u a l l y complete. 88 The use of composting t o i l e t s promotes the development of a t t i t u d e s , perhaps  even l i f e s t y l e s , that are c h a r a c t e r i s t i c of people i n a Conserver Society. Their use requires a greater awareness of b i o l o g i c a l systems and encourages the r e c y c l i n g of p h y s i c a l materials, at the l e v e l of the i n d i v i d u a l and of the community. This i s an important step i n achieving a Conserver Society, because i t brings about a state of consciousness that makes the next steps much e a s i e r . Chapter IV also explored the p o t e n t i a l a p p l i c a t i o n s of composting t o i l e t systems, and concluded that they could be i n s t a l l e d e a s i l y , or with a c e r t a i n amount of resourcefulness, i n use-situations e x h i b i t i n g a wide v a r i a t i o n i n scale and density. The only exception i s high density, large urban regions where e x i s t i n g investment i n sewer systems should be made use of. The only fundamental objection to composting t o i l e t systems i n urban areas i s that they work against the e f f i c i e n t concentration of the nutrients i n human wastes so that they can be returned to the land to grow more food. The argument i s that since a g r i c u l t u r a l lands 'export' nutrients to urban dwellers, the nutric;r*-r. which are not used should be exported back to the farms to f e r t i l i z e subsequent crops. Composting t o i l e t s needlessly compli-cate t h i s strategy by concentrating the nutrients i n small amounts, rather than at c e n t r a l i z e d l o c a t i o n s , thus r e q u i r i n g the further, and perhaps pro-h i b i t i v e expense of an extra l e v e l of transportation. This argument i s c e r t a i n l y v a l i d , at l e a s t f o r our present food p r o v i s i o n system, and again confirms the need f o r a d i v e r s i t y of sewage systems. But i s the argument s t i l l v a l i d i n l i g h t of recent events which pointed up the alarming v u l n e r a b i l i t y of our food p r o v i s i o n systems? B r i t i s h Columbians are very dependent on food which i s grown thousands of miles away, i n places l i k e C a l i f o r n i a , F l o r i d a and Mexico, and t h i s past 89 winter showed how t h i s food supply could be cut o f f by c l i m a t i c changes over which humans have no c o n t r o l , not to mention how i t could be af f e c t e d by economic and p o l i t i c a l changes which are c o n t r o l l e d by humans. The obvious s o l u t i o n to t h i s v u l n e r a b i l i t y i s to grow more food i n B r i t i s h Columbia. Chapter IV has already shown that use of composting t o i l e t s can reduce the amount of a g r i c u l t u r a l land that i s taken out of food production, but i t w i l l a lso be necessary to make better use of a l l the arable land that i s covered with houses and asphalt. In order to u t i l i z e some of t h i s land t h i s way, i t w i l l a l s o be necessary to encourage urban dwellers to grow more of t h e i r own food, because the gardens of any urban area have a great p o t e n t i a l f o r i n t e n s i v e food production ( c i t i e s almost always grow up on prime a g r i -c u l t u r a l land). One of the f i r s t requirements of such i n t e n s i v e h o r t i c u l t u r e i s a very f e r t i l e s o i l , and thus composting t o i l e t s have a second b e n e f i c i a l impact on increasing s e l f - s u f f i c i e n c y i n food production: the r e l a t i v e l y small concentration of high q u a l i t y s o i l amendment produced by a composting t o i l e t turns out to be i n exactly the r i g h t place to achieve the best r e s u l t s . R e c a l l i n g once again the fourth p r i n c i p l e of a Conserver Society, the composting t o i l e t i s not the complete or f i n a l s o l u t i o n to our sewage di s p o s a l problems. The evolution of the t o i l e t i t s e l f w i l l continue and there are some s i t u a t i o n s which w i l l require d i f f e r e n t techniques, although the basic approach—viewing human wastes as a resource, not a problem—should be the same. Nevertheless, the composting t o i l e t system i s an eminently d e s i r a b l e system f o r the proper d i s p o s a l of human body wastes and should be considered by most communities which need to i n s t a l l or upgrade a sewage system. 90 V.B RECOMMENDATIONS As a r e s u l t of Chapters II and I I I , i t i s evident that not only can the composting t o i l e t system achieve better r e s u l t s than conventional systems, i t can also cost considerably l e s s i n monetary and environmental terms. Yet i t has received l i t t l e r e c o g n i t i o n by the regulatory agency i n t h i s province. I t i s therefore recommended that the Government of B r i t i s h  Columbia amend the Sewage Disposal Regulations to permit e x p l i c i t l y the use  of composting t o i l e t and associated greywater systems on a s i t u a t i o n - s p e c i f i c basis and that the r e s u l t s of monitoring the performance of various  types and makes of composting t o i l e t s be used to draw up guidelines f o r general use as soon as these r e s u l t s become a v a i l a b l e . Although the d e s i r a b i l i t y of the composting t o i l e t system has been proved by Chapters II and I I I , and although the implications of i n s t a l l i n g the system f o r a whole communitiy have been shown to be p o s i t i v e by Chapter IV, no one community has yet converted to the system. U n t i l one does, i t i s u n l i k e l y that others w i l l take the r i s k of being the f i r s t . I t i s therefore  recommended that the B r i t i s h Columbia M i n i s t r y of Municipal A f f a i r s designate  one or more communities with serious sewage problems and subsidize t h e i r  conversion to composting t o i l e t s as an experiment to be monitored and  evaluated i n terms of the e c o l o g i c a l , economic and s o c i a l i m p l i c a t i o n s . F i n a l l y , i f i t i s government p o l i c y to subsidize sewer programs i n communities which are unable to pay the f u l l cost, then i t should a l s o be government p o l i c y to subsidize the i n s t a l l a t i o n of composting t o i l e t systems by i n d i v i d u a l s , as we l l as communities, that are unable to pay the f u l l cost, since the costs of t h i s system can be borne d i r e c t l y by i n d i v i d u a l s . I t i s therefore recommended that the National Housing Act be amended to 91 allow Central Mortgage and Housing Corporation to provide f i n a n c i a l  assistance f o r i n s t a l l a t i o n of composting t o i l e t systems d i r e c t l y to  households i n need, and to include i n s t a l l a t i o n of lar g e - s c a l e composting  t o i l e t systems among those municipal c a p i t a l investment projects f o r which  government funding i s a v a i l a b l e . 92 LIST OF REFERENCES 1. ATCO LEASING. " I n s t a l l a t i o n Instructions"; "What Happens i n s i d e the Humus-Toilet?"; and promotional/performance l i t e r a t u r e on the Humus-Toilet. 2. BASU, Dipak, Surrey Engineering Department. Personal communications 3. BRITISH COLUMBIA. 1974, 1975. Health Branch Administrative C i r c u l a r s 74/149 and 75/104. 4. - 1975. Health Act: Sewage Disposal Regulations. B.C. Regulation 577/75. V i c t o r i a , B.C.: Queen's P r i n t e r . 5. 1961. S o i l Map of Surrey M u n i c i p a l i t y . S o i l Survey Branch, M i n i s t r y of A g r i c u l t u r e . 6. CENTRAL MORTGAGE AND HOUSING CORPORATION. "Assistance f o r Water and Sewerage Projects: A Guide f o r Obtaining F i n a n c i a l Aid through CMHC under the National Housing Act. Ottawa. ."CANWELL - A Canadian Waste Management System: Technical Information". Prepared for HABITAT - The UN Conference on Human Settlements. 8. CIVIL MUNICIPAL CONSULTING ENGINEERING LTD.. 1976. Bridgeview: Sanitary Sewers F e a s i b i l i t y Study. Prepared f o r the Corporation of the D i s t r i c t of Surrey. Vancouver. 9. CLARK, John W., VIESSMAN, Warren J r . and HAMMER, Mark J . . 1971. Water Supply and P o l l u t i o n Control (second e d i t i o n ) . Scranton, Penn-s y l v a n i a : International Textbook Co.. pp 271-72 10. CLIVUS-MULTRUM USA, INC. Personal communications and promotional/ performance l i t e r a t u r e 11. COWIE, A./EIKOS PLANNING AND ENVIRONMENTAL DESIGN GROUP. 1976. "Overview Planning Assessment: Subdivision A p p l i c a t i o n and Panorama/ Colebrook Area Plan Concept by A p l i n and Martin". Prepared for the D i r e c t o r of Planning, D i s t r i c t of Surrey 12. DE JOUNGE, Lars. 1976. "The Toa-Throne - A New Composting T o i l e t " . Compost Science. Vol 17, No 4, Sept/Oct; pp 16-17 13. DELIKATNY, F.P., D i s t r i c t Superintendent, B.C. Parks Branch. Personal communication - January 31, 1977 14. DORCEY, Anthony H.J., ed. 1976. The Uncertain Future of the Lower Fraser. Vancouver: Westwater Research Centre, U n i v e r s i t y of B r i t i s h Columbia 15. ENVIROSCOPE, INC. Promotional l i t e r a t u r e f o r the Toa-Throne 93 16. EKLUND, L.T.. 1974. "The Non-Flush T o i l e t i s P o s s i b l e " . Water and P o l l u t i o n Control. Vol 17. . Personal communications and informational l i t e r a t u r e on the Mullbank t o i l e t 18. ESTABROOK, Barry. 1976. "Privy Redux". Harrowsmith. Vol 1, No 4, Nov/ Dec; pp 8-15 19. EVANS, John, (no date). "The Dry T o i l e t System: I t s Impact on an Unserviced Newfounfland Community". Unpublished manuscript 20. . . . Personal communication 21. FOGEL, Margaret and LINDSTROM, C a r l , (no date), "The Treatment of Household Washwater i n Homes Equipped with the Clivus-Multrum Organic Waste Treatment System". Clivus-Multrum USA, Inc. 22. GALLUP, R. 1974. " I f a C i t y Engineer Can't Handle Garbage - He Should Quit". Interviewed i n Water and P o l l u t i o n Control, January 23. GOUGE, Michael F.. 1975. A F i e l d Study of a Household Package Treatment Plant. U n i v e r s i t y of B r i t i s h Columbia M.Sc. Thesis i n C i v i l Engineering. Vancouver, p 40 24. GRENO, Robert, Surrey Planning Department. Personal communications 25. HILL, Stuart B. "Composting f o r Garden and Farm". MacDonald Journal. Montreal: M c G i l l U n i v e r s i t y 26. HILLS, Lawrence D. 1972. "The Cl i v u s T o i l e t - Sanita t i o n without P o l l u t i o n " . Compost Science. Vol 13, No 3, May-June; p.10 27. HINDLEY, A., B r i t i s h Columbia Health Branch, V i c t o r i a , B.C.. Personal communication 28. HYPES, Warren D. 1975. "Characterization of T y p i c a l Household Grey Water". Manual of Greywater Treatment and P r a c t i c e , Part I I . Santa Monica, CA.: Monogram Industries 29. HUBER, John, Sales Service Representative, ATCO Leasing. Personal communications 30. HUSDON, Ross, resident of Panorama Ridge West, Surrey, B.C.. Personal communication 31. JOHN, Matt K. and VAN LAERHAVEN, Cornelius J . 1976. " E f f e c t s of Sewage Sludge Composition, A p p l i c a t i o n Rate and Lime Regime on Plant A v a i l a b i l i t y of Heavy Metals" Journal of Environmental Quality. Vo l 5, No 3, July-Sept 32. LAAK, Rein. 1975. "Relative P o l l u t i o n Strengths of Undiluted Waste Mat e r i a l s Discharged i n Households and the D i l u t i o n Waters Used fo r Each". Manual of Greywater Treatment and P r a c t i c e , Part II Santa Monica, CA.: Monogram Industries 94 33. LANGER, Hans, Regional Supervisor, Northern P u r i f i c a t i o n Systems Ltd. Personal communications, promotional/specifications l i t e r a t u r e on package treatment systems. 34. LEICH, Harold. 1975. "The Sewerless Society". B u l l e t i n of the Atomic S c i e n t i s t s . Vol XXXI, No 9, November 35. . 1976. "New Options f o r a Sewerless Society". Compost Science. Summer 36. LEWIS, Jay. 1976. " L i f e with a C l i v u s " . Harrowsmith. Vol 1, No 4, Nov/Dec;pp 12-13 37. LINDSTROM, C a r l R. 1975."The Clivus-Multrum System: Composting of T o i l e t Waste, Food Waste and Sludge w i t h i n the Household". In Water  P o l l u t i o n Control i n Low Density Areas. Hanower, New Hampshire: U n i v e r s i t y Press of New England 38. Personal communication 39. LIPSON, S.L. 1974. Study of Municipal Services f o r Bridgeview and South Westminster Areas, Surrey, B.C. 40. MICROBIOLOGICAL INSTITUTE, AGRICULTURAL COLLEGE OF NORWAY, i n co l l a b o r a t i o n with CONSUMER REPORT. "21 B i o l o g i c a l T o i l e t s " Extracted from Consumer Report No. 10 41. MONOGRAM INDUSTRIES, INC. 1974. Manual of Greywater Treatment and P r a c t i c e , Part I. Santa Monica, CA.: Monogram Industries 42. McKERNAN, J.M. and MORGAN, D.S.. 1976. "Experience with the C l i v u s -Multrum and Mull-Toa T o i l e t s i n Northern Manitoba". Winnipeg: Manitoba Department of Northern A f f a i r s 43. NICHOLS, Wayne H. 1976. "Analysis of B a c t e r i a l Populations i n the F i n a l Product of the Clivus-Multrum". Saint Louis, M i s s o u r i : Center f o r the Biology of Natural Systems; ppl4-16 44. NORHEIM, Bjorn, Sons of Norway r e c r e a t i o n a l a s s o c i a t i o n , Prince George, B.C.. Personal communication, A p r i l 1977 45. OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY. "Experimental On-Site Sewage Treatment and Disposal Systems Program". Portland, Oregon 46. PLEWS, Gary D. "Modifying the Wastewater C h a r a c t e r i s t i c s " . Paper presented to the Northwest On-Site Waste Water Disposal Short Course, Seattle, WA., December 8-9, 1976 47. READ, Simon. 1975. "Consumption of Energy i n Single Family Homes i n the Greater Vancouver Area: Implications f o r Energy Planning and P o l i c y " Unpublished paper i n Planning 550(05) - Directed Studies i n Energy Planning , School of Community & Regional Planning, U n i v e r s i t y of B.C., Vancouver 95 48. RECREATION ECOLOGY CONSERVATION OF U.S., INC, "Ecolet - Self-contained T o i l e t " . Promotional/performance information 49. RONAYNE, Mark P., Sub-surface and A l t e r n a t i v e Sewage Systems Section, Water Quality D i v i s i o n , Oregon Department of Environmental Qual i t y . Personal communication 50. RYBCZYNSKI, Witold, ed. 1973. "Stop the Five-Gallon Flush: A Survey of A l t e r n a t i v e Waste Disposal Systems". Montreal: Minimum Cost Housing Group, School of Architecture, M c G i l l U n i v e r s i t y ; pp 78-79 51. • _. 1976. "Small i s B e a u t i f u l But Sometimes Bigger i s Better". Solar Age. May 52. . 1976. Personal communication regarding energy use of Cli v u s Minimus 53. SLATER, Michael, A p l i n and Martin Ltd., Surrey B.C.. Personal communication regarding sewer system costs i n Panorama Ridge West 54. SURREY PLANNING DEPARTMENT. 1976. The Bridgeview Community Plan. Corporation of the D i s t r i c t of Surrey 55. SYMBALUK, L.G., Alb e r t a Housing Corporation. Personal communication, March 1977 56. TALBOT, , Greater Vancouver Sewer and Drainage D i s t r i c t . Personal communication regarding Annacis Island Treatment Plant 57. TYE, Len, Vancouver Branch, CMHC. Personal communication, A p r i l 1977 58. ULOFF, V i c t o r , Northern P u r i f i c a t i o n Systems Ltd. Personal communications 59. VALDMAA, Kaju. 1974. :'xhe Mullbank T o i l e t " . Compost Science, vol 15, No 5, Nov-Dec; pp 23-27 60. WALKER, Matt, Surrey Engineering Department. Personal communication 61. WASHINGTON STATE DEPARTMENT OF SOCIAL AND HEALTH SERVICES. 1975. Guidelines Governing the Design, A p p l i c a t i o n and Operation of Composting T o i l e t s " 62. WINNEBERGER, J.T.. 1975. "Separation of Water-Borne Wastes". Manual of Greywater Treatment and P r a c t i c e , Part I I . Santa Monica, CA.: Monogram Industries, Inc. 63. WRIGHT, Jim, Vacusans Systems Ltd., Vancouver, B.C.. Personal communications. 96 APPENDICES APPENDIX A: DESCRIPTION AND EVALUATION OF FOUR COMPOSTING TOILETS The four t o i l e t makes discussed i n t h i s appendix are Clivus-Multrum and Toa-Throne, representing large, sloping f l o o r t o i l e t s ; and Humus-T o i l e t (Mulltoa) and Mullbank ( E c o l e t ) , representing small, e l e c t r i c t o i l e t s Each t o i l e t w i l l be described i n terms of (a) design and p h y s i c a l charac-t e r i s t i c s ; (b) capacity; (c) i n s t a l l a t i o n and management requirements; (d) monetery cost and energy requirements; (e) performance i n e x i s t i n g I n s t a l l a t i o n s ; and (f) o v e r a l l evaluation. The d e s c r i p t i o n and evaluation i s based p a r t l y on information from other reports on the t o i l e t s , and i t w i l l be referenced accordingly. The remainder of the information i s from promotional m a t e r i a l , s p e c i f i c a t i o n s and personal communications with manufacturers and/or d i s t r i b u t o r s of each t o i l e t . I t i s not possible to describe each t o i l e t to the same l e v e l of d e t a i l because of the varying amounts of information a v a i l a b l e f o r each t o i l e t ; t h i s i s e s p e c i a l l y the case for Toa-Throne and Mullbank, f o r which reports of a c t u a l performance " i n the f i e l d " could not be obtained. F i n a l l y , the descriptions are not intended to s u b s t i t u t e for comp-rehensive i n s t a l l a t i o n and operation manuals , which should, and i n most cases can be obtained from the manufacturer at time of purchase. Further-more, the evaluation of each t o i l e t represents only the opinion of the author, based almost e n t i r e l y on t h e o r e t i c a l considerations and second-or third-hand evidence, and i s intended as a.general guide, not as a f i n a l judgement on the advantages or disadvantages of any one t o i l e t . LARGE, SLOPING FLOOR TOILETS The c e n t r a l feature of these t o i l e t s , i n a d d i t i o n to the r e l a t i v e l y large s i z e , i s the angle at which the f l o o r of the decomposition chamber slopes down toward the end from where the f i n i s h e d humus i s u l t i m a t e l y removed. The angle i s designed so that by the time organic matter slowly s l i d e s down the slope, i t i s decomposed and mineralized by the time i t reaches the bottom. The angle also enables urine to drain down to the t h i c k e s t part of the s t a r t e r bed containing the microorganisms which decompose urine. The sloping f l o o r also promotes aeration by breaking up 97 the mass, since material i s forced to s l i d e over and around the v e n t i l a t i o n ducts i n the chamber. This design feature eliminates the need f o r mechanical turning or s t i r r i n g . CLIVUS-MULTRUM The Clivus-Multrum i s manufactured and d i s t r i b u t e d i n North America by Clivus-Multrum USA, Inc., 14A E l i o t Street, Cambridge, Massachusetts 02138. (a) Design and P h y s i c a l C h a r a c t e r i s t i c s Garbage Chute i n Cabinet CLIVUS-MULTRUM TOILET A i r intake 98 Diagram Notes; 1. T o i l e t chute i s wider at the bottom than at the top to avoid f o u l i n g of the sides, 2. A i r ducts are open on the underside to prevent blockage by f a l l i n g m a t e r i a l . 3. A i r i s drawn i n through m a t e r i a l entrance ports as we l l as a i r intakes. 4. Access port provided to enable r e t r i e v a l of a r t i c l e s which a c c i d e n t a l l y f a l l i n t o the garbage chute or t o i l e t , S p e c i f i c a t i o n s Shipping weight - 136 kg Average volume - 4.5 cubic metres Slope angle - 30° Maximum P i l e Temperature - 32 °C Chamber material - reinfo r c e d polyester (b) Capacity The standard tank accommodates three persons, with allowance f o r v i s i t o r s , on a continuous b a s i s ; larger numbers of people can be accomm-odated on a seasonal or intermittent b a s i s . For increased capacity, extra midsections can be added: one section increases the capacity to four to seven persons; two sections permits continuous use by eight to twelve people. I f a n t i c i p a t e d , extra midsections should be i n s t a l l e d i n i t i a l l y , since subsequent i n s t a l l a t i o n i s d i f f i c u l t . A f t e r a two year breakin period, continuous production of humus i s at the rate of about 45 l i t r e s per person per year[37] (c) I n s t a l l a t i o n and Management Requirements The C l i v u s i s usu a l l y i n s t a l l e d beneath the house, i n a f u l l or par-; t i a l basement, or outside, p a r t l y buried, i f the climate permits. In the l a t t e r case, i t may be used outdoors, or i t may be connected to the t o i l e t i n the house by a conveyer system ( s t i l l under development). For operation according to design, a common wa l l between bathroom and kitchen i s required; houses without t h i s arrangement can s t i l l have a Cli v u s i n s t a l l e d , f o r the a d d i t i o n a l s l i g h t inconvenience of carrying kitchen scraps down to the base-ment and puttin g them d i r e c t l y into the chamber through the access port provided or, a l t e r n a t i v e l y , running the garbage chute through the f l o o r 99 and having the opening i n a room other than the kitchen. Wherever i t i s i n s t a l l e d , the minimum space requirements are 1.22 metres by 2.46 metres f l o o r space and 2.14 metres v e r t i c a l clearance. As i n a l l composting t o i l e t s , proper preparation of the s t a r t e r bed i s very important. Garden s o i l or compost w i l l provide the necessary microorganisms, while peat moss and leaves w i l l provide the necessary absorbency. I f the s t a r t e r bed i s compacted against the lower edge of the l a s t v e r t i c a l p a r t i t i o n , as shown i n Figure 4, the construction of the Clivus makes i t almost impossible to remove material which has not been mineralized[37]. Once put i n place, the s t a r t e r bed renews i t s e l f constantly and needs no further a t t e n t i o n . Because of i t s large s i z e and r e s i l i e n c e , management pr a c t i c e s f or the C l i v u s are not very exacting; however, r e g u l a t i o n of humidity and C/N (by adding carbonaceous material) w i l l d e f i n i t e l y improve the e f f i c i e n c y of decomposition. With the possible exception of a small fan, there are no moving par t s , so that r e p a i r a c t i v i t i e s are n e g l i g i b l e . Other than cleaning the t o i l e t chute p e r i o d i c a l l y (which i s no more onerous than cleaning a normal t o i l e t bowl), the only management a c t i v i t y i s removal of the humus. (d) Monetary Cost and Energy Requirements The accompanying p r i c e l i s t / o r d e r form from Clivus-Multrum, Inc. includes a s p e c i a l package o f f e r of $1485 f o r the regular s i z e tank, but excluding shipping and i n s t a l l a t i o n costs, The C l i v u s i s guaranteed for ten years, except f o r the t o i l e t seat and mechanical options which have a two-yearguarantee. / (e) Performance i n E x i s t i n g I n s t a l l a t i o n s Since 1974, the Manitoba Department of Northern A f f a i r s has been mon-i t o r i n g the performance under northern s o c i a l and e c o l o g i c a l conditions of Clivus-Multrums and Humus-Toilets i n several l o c a t i o n s . According to the interim report[42], the department wished to determine the u t i l i t y of these systems f o r several reasons: 1) The majority of people l i v i n g i n small communities i n northern Manitoba do not have access to sewage treatment of any kind; 2) Subdivision configurations dictated by the economics of pro-v i d i n g sub-surface sewer and water systems are i n c o n f l i c t with the c u l t -u r a l and s o c i a l needs of many people, p a r t i c u l a r l y i n Indian and Metis communities; 3) The incidence of g a s t r o - i n t e s t i n a l i n f e c t i o n s , r e s u l t i n g ) CLIVUS-MULTRUM P R I C E L I S T / O R D E R F O R M ftrKnrt Item 9 Description Price 101 C O M P L E T E SPECIAL P A C K A G E $1,485.00 CONTAINERS A N D MIDSECTIONS 07 Insulated tank, regular size (includes hardware, sealant and porthole) 1,300.00 02 Uninsulated tank, large size {includes hardware, sealant and porthole) 1,375.00 071 Midsection, insulated, for adding capacity to tank #07. Includes sealant and hardware 150.00 021 Midsection, uninsulated, for adding capacity to tank #02. Includes sealant and hardware 150.00 VENTILATION 70 Vent pipe, 6" diameter, galvanized steel, 30 gauge, 5 ft. sections (5 sections usually needed) 3.34 71 Elbows, 6" flexible, galvanized steel, 30 gauge 2.00 72 Connector plate for #70 pipe, galvanized steel 1.00 75 Roofjacfc, adjustable, 12" galvanized steel (if roof pitch is greater than 30°, see "Ventilation Considerations") 9.50 76 Rotary roof ventilator, 12" galvanized steel 21.70 77 Ventilation fan, 6", D-J model '. 25.00 79 Insulation, 6" for vent pipe, Owens-Corning pre-formed, one box of five 3 ft. sections (15 ft.) . . 30.00 80 RPM regulator for fan (dimmer switch) 10.75 81 Cap for vent pipe insulation, galvanized steel, with insect screen 2.00 82 Pipe, 12* 2 ft. sections, galvanized steel, 24 gauge (2 sections usually needed for vent above roof line) 4.11 83 Elbow for 12" pipe, galvanized steel, 24 gauge, flexible (needed for roof jack adjustment if roof pitch is over 30° 6.50 TOILETS , K I T C H E N W A S T E INLETS and ACCESSORIES 11 Toilet stool, solid hardwood, seat and cover and liner included . . . 97.00 16 Toilet stool, Swedish, polyfor.ned, white, with liner, seat ?nd cover included. . 50.00 18 Toilet seat and cover only, with hardware 10.00 20 Toilet chute, 16* diameter, for use with tank #02, in public installations only . . 24.00 42 Connector, 16" diameter, for use with item #20 only 10.00 86 Kitchen Waste Lid, polished aluminum 46.00 55 Butcher block kitchen waste assembly, w/stainless steel bowl and liner in-cluded 75.00 82 Chutes, 12'2 ft. sections, galvanized steel, 24 gauge (4 sections usually needed for kitchen waste and toilet chutes combined) * . . , 4.11 83 Elbow for 12" chute, galvanized steel, 24 gauge, flexible (needed only when kitchen waste lid is vertically installed, (see "Kitchen waste lid and varia-tions") ... 6.50 84 Insulation, 12" Owens-Coming, pre-formed, box of two 3' sections for toilet and kitchen waste chutes) 28.00 . 85 Connector plates, for #82 (2 are usually needed, one each for toilet and kitchen waste chutes) 2.00 C R E D I T and SUBSTITUTIONS F R O M SPECIAL P A C K A G E Credit taken for items #77 and #80 , Credit taken for toilet #16 101 Clivus Multrum USA, Inc.. SPECIAL PACKAGE OFFER Complete Clivus Multrum System $1,485.00 This package includes every part* needed to install an average system ser-vicing one toilet on the first floor. It offers a saving of $109. under the combined cost of the parts if they are ordered individually. It is designed to serve up to three people, year round. If usage will be greater, see "Capacity Considerations" below. The Complete Package includes: Insulated Tank (#07) with aluminum ponhole (#86) Ventilation Kit including: #70 (50 ft.), #71 (4 pieces), #72 (1 piece), #75 (1 piece), #76 (1 piece), #T7 (1 piece), #79 (5 three ft. sections), #80 (1 piece), #81(1 piece), #82 (2 two ft. sections). Toilet Stool (#16) and Kitchen Waste Lid (#86) including the following • parts: #82 (4 two ft. sections), #84 (2 three ft. sections), #85 (2 pieces). Total, if purchased individually $1,594. Package Price $1,485. SAVINGS.. S109. M> parts substitutions or returns may be made when ordering the Com-plete Package, except as noted on the following pages. 'Excluding materials which are easier and cheaper to obtain locally (e.g. material for support cradle and vent insulation for attic and above roof). 14A ELIOT STREET CAMBRIDGE, MASS. 02138 (617)491-5820 * S i - COMPLETE «82 PACKAGE .#75 C A P A C I T Y C O N S I D E R A T I O N S The insulated tank (#07) is large enough to serve three persons year round with allowances for visitors. If 4-7 persons are to be served, one midsection (£071) is also required; if 8-12 persons, a second midsection is needed. If future needs are estimated to include additional users, one or more midsections should be ordered and installed initially, since add-ing midsections later is a difficult installation job. Naturally, if the system is to be used only seasonally or inter-mittently, it can accommodate larger numbers of people during that period. V E N T I L A T I O N C O N S I D E R A T I O N S Where electrical service is available, it is recommended that all item numbers listed in the Ventilation section of the Price List/Order Form (with the possible exception of #71 when the vent tube line has no bends) be ordered in order to assure a properly functioning vent system. Where no electrical service is available, #77 and #80 may be eliminated from the Special Package and indicate that credit is taken at the bottom of the order form. If your roof pitch is greater than 30°, you will need a 12* elbow (#83) to supplement the adjustable roof jack. This item is hot included in the Special Package offer. K I T C H E N W A S T E L I D A N D V A R I A T I O N S The aluminum lid (#86) doubles as a kitchen waste depository' and as an access porthole through which articles inadcr-tently dropped into the Clivus may be retrieved. Therefore, two lids are included in the Package. The kitchen waste lid may be installed in several positions and locations. For example: the surface of a counter, in a closet or cabinet floor, or the side of a wall or cabinet. No additional parts for installing the lid on any horizontal sur-face are required when ordering the Special Package. If the lid is to be installed on a vertical surface (sec fig. 2), a 12" elbow (#83) must be purchased, and this item is not included in the Package. If you are ordering from the parts list or in addition to the Package you may prefer the butcher block kitchen waste assembly (#55) which is suitable only for kitchen counters. 102 from contamination of water supplies by sewage, i s much higher i n the North than i n the South; and 4) Because of conditions p r e v a i l i n g i n the North, the c a p i t a l costs of providing standard services to f i f t y - t w o small communities would be on the order of $91 m i l l i o n . The program i n s t a l l e d three Clivus-Multrums and nine Humus-Toilets (the Humus-Toilet part of the tes t w i l l be described l a t e r i n t h i s appendix). The average i n s t a l l e d cost of the Clivus u n i t s was $2335, although i n s t a l l -a t i o n i n a basement rather than an unheated crawlspace would have reduced the cost by almost $400. D a i l y operating costs f o r e l e c t r i c i t y consumed by fan and supplementary heating tapes was about $0.04. The study i d e n t i f i e d several problem areas, i n c l u d i n g f l u i d accum-u l a t i o n , low system temperature, slow waste accumulation and f l y i n f e s t a t i o n . In every case, the problem was traced to the unique p h y s i c a l conditions or improper p r a c t i c e . A major reason f o r f l u i d accumulation was the dumping of washwater i n t o the t o i l e t instead of into the outdoor soak p i t . Kitchen scraps were l e f t uncovered i n the i n l e t bowl and offered a natural depos-i t o r y f o r f l y eggs i n the summer; even so, f l y i n f e s t a t i o n s were infrequent and occurred i n one house only. And because of the r e l a t i v e l y small amounts of f r e s h produce consumed i n northern communities, the u n i t s received l i t t l e vegetable and f r u i t wastes. Not only did the lack of carbonaceous materials r e s u l t i n low temperature because of a low C/N, but because waste accumu-l a t i o n was so slow, what heat was produced was quickly d i s s i p a t e d i n the r e l a t i v e l y empty chamber. The study ?vithors are cu r r e n t l y experimentin? with a l t e r n a t i v e carbon sources such as peat moss and sawdust. The i n t e r i m report concludes that i n s p i t e of the p h y s i c a l impediments to i n s t a l l a t i o n of the C l i v u s under the t e s t conditions, the system can provide simple and e f f e c t i v e s a n i t a t i o n when properly i n s t a l l e d and ad-equately loaded (inadequate loading l e d to an accumulation of f l u i d that can pose a hygiene problem when disposing of i t [ b u t see Appendix B]). The authors f e e l that the large s i z e i s the key to the Clivus'dependability and that i t s performance w i l l improve with increased loading. Chapter I I also b r i e f l y mentioned a Cl i v u s that had been i n s t a l l e d i n the Okanagan by an i n d i v i d u a l named Jay Lewis[36]. The t o t a l cost of t h i s system, i n c l u d i n g a s t e e l tank f o r holding greywater p r i o r to discharge i n a nearby wooded area, was about $2000. In t h i s case the house was b u i l t around the t o i l e t . The t o i l e t i s over a year o l d now and has experienced 103 only minor problems c h a r a c t e r i s t i c of the break-in period of the C l i v u s . There was some accumulation of f l u i d during the e a r l y stages, but i t was b a i l e d out and used, with apparently good r e s u l t s , to water the shrubs. Insect populations fluctuated w i l d l y , depending on season, temperature and use of a mild i n s e c t i c i d e . And i n s p i t e of a twenty-foot stack, v e n t i l a t i o n of odour was sometimes marginal, but the author i s remedying t h i s by a l t e r -ations to the vent cover and t o i l e t seat cover. In compensation f o r these rather temporary problems, the household uses l e s s than one thousand gallons of water per month, produces f e r t i l i z e r f o r i t s f r u i t trees and enjoys the good f e e l i n g s r e s u l t i n g from not p o l l u t i n g the waters of the Okanagan Va l l e y any more. ' A f i n a l example i s an experimental Clivus-Multrum i n s t a l l e d i n a small v i l l a g e east of Montreal by Witold Rybczynski In t h i s case, the prob-lem of odour, e s p e c i a l l y on s t i l l , humid days common to the St. Lawrence v a l l e y i n summer, was serious enough to require the i n s t a l l a t i o n of a small fan. F l i e s were also a problem f o r a while, following the a d d i t i o n of p e e l -ings from 300 pounds of tomatoes, but the fan should help t h i s problem, too, u n t i l the necessary balance i s achieved[18]. (f) O v e r a l l Evaluation To a great extent, the evaluation of large t o i l e t s as opposed to small t o i l e t s i n Chapter I I was written with the C l i v u s i n mind. Perhaps i t s greatest disadvantage i s the r e l a t i v e l y high cost. This irs followed by th£ ' i m p r a c t i c a l i t y or d i f f i c u l t y of i n s t a l l i n g the C l i v u s i n some e x i s t i n g houses, although t h i s can be overcome with enough ingenuity and desir e on the part of the user. Opposing these i s the great advantage of a sewage sys-tem that i s simple, r e s i l i e n t , safe and dependable. TOA-THRONE The Toa-Throne i s manufactured i n Sweden by Toa-Throne AB and d i s -t r i b u t e d i n North America by Enviroscope, Inc., P.O. BOX 752, Corona d e l Mar, CA. 92625. I t i s a v a i l a b l e i n B r i t i s h Columbia from Mr. and Mrs. G.C. G i l e s , 1744 Llandaff Place, V i c t o r i a , B.C. V8N 4V1. 104 With reference to Figure 5, the Toa-Throne appears to be a compromise between the s i m p l i c i t y of the large t o i l e t s and the s i z e of the small t o i -l e t s . I t r e t a i n s the sloping f l o o r but i s only about one-quarter the v o l -ume of the C l i v u s . V e n t i l a t i o n Stack T o i l e t s t o o l Inspection Opening Width 99cm •164cm FIGURE 5: TOA-THRONE -Access door Starter bed Other d i f f e r e n c e s between i t and the C l i v u s are the use of the t o i l e t opening f o r kitchen wastes as we l l as f o r t o i l e t wastes, and the " a i r s t a i r c a s e " , which allows a i r to penetrate the p i l e from below. This feature has apparently been added since the evaluation made by the A g r i c u l t u r a l College of Norway i n 1974-75[40] and the s i z e of the model used i n that t e s t (and which received a r a t i n g of 'Good') was somewhat lar g e r than the present model. Yet another d i f f e r e n c e between the present model and the test model i s the slope of the f l o o r . In the test model, the slope angle was 28°, but i n a recent p u b l i c a t i o n , the president of Enviroscope, Lars De Jounge, gave the slope angle of the a i r s t a i r c a s e as 41°[12]. The r o l e of> the a i r ducts i n the Cli v u s i n breaking up the mass i s performed i n the Toa-Throne by the l o n g i t u d i n a l d i s t r i b u t i o n conduits. 105 The t o i l e t comes i n two configurations: the simplest, intended f o r outdoor and/or non-powered s i t u a t i o n s , has the t o i l e t seat placed d i r e c t l y on the chamber; the other, intended f o r bathroom i n s t a l l a t i o n , has an e l e c -t r i c fan to f a c i l i t a t e v e n t i l a t i o n and aeration,and connecting pipe from the bathroom t o i l e t commode to the tank below the f l o o r . The fan was also used i n the A g r i c u l t u r a l College t e s t , and seems to be the r u l e rather than j u s t an option. When e l e c t r i c power i s not a v a i l a b l e , the t o i l e t makes use of n a tural d r a f t . (b) Capacity The Toa-Throne i s designed f o r regular use, i n c l u d i n g t o i l e t and kitchen wastes, by four to s i x people, and can accommodate more than s i x on an occasional b a s i s . I t i s recommended that f i r s t removal of humus not take place u n t i l there i s s u f f i c i e n t mass i n the p i l e to absorb occasional overloading with urine. Subsequently, humus can be removed from once to three times per year, depending on the number of users'. Humus production i s claimed to be approximately 27 kilograms/person/year. (c) I n s t a l l a t i o n and Management Requirements Toa-Throne can be i n s t a l l e d outdoors, i n a basement connected to the t o i l e t on the main f l o o r or on the main f l o o r connected to the t o i l e t on the second f l o o r . I n s t a l l a t i o n of the chamber i t s e l f on upper f l o o r s i s po s s i b l e i f the f l o o r i s r e i n f o r c e d to take the weight. I n s t a l l a t i o n m a t erial not included with the unit are v e n t i l a t i o n duct, timber f o r a support frame, peat moss and soil/compost f o r the s t a r t e r bed, and necessary i n s u l a t i o n . The management of the t o i l e t i s s i m i l a r to the C l i v u s . I t i s important to ensure an adequate depth of s t a r t e r material, p a r t i c u l a r l y at the lower end, i n order to absorb urine, and the operation manual stresses that the unit must not be overloaded with urine i n the i n i t i a l months before b u i l d -up of m a t e r i a l . This requires p e r i o d i c checking of the moisture content of the lowest s e c t i o n of the s t a r t e r bed. The manual also suggests p e r i o d i c additions of lime, as w e l l as kitchen scraps, to "maintain a good decom-posing atmosphere" and recommends hanging a S h e l l "No Pest S t r i p " j u s t i n s i d e the container. Care must be taken to make an a i r - t i g h t s e a l each time the access hatch cover i s replaced to ensure that a i r i s drawn through the a i r s t a i r c a s e only. The v e n t i l a t o r fan should operate at a l l times, except 106 under conditions of high ambient temperature and low humidity when constant v e n t i l a t i o n might cause excessive dehydration and adversely a f f e c t m i c r o b i a l a c t i o n . A timer switch f or the fan i s recommended f o r such conditions. The maximum capacity f or the t o i l e t i s obtained at an operating temp-erature of 25 °C i n s i d e the u n i t . Normal capacity (four - s i x persons' urine production) requires temperatures above about 18-19 °C. I f t h i s temperature cannot be maintained a heating element w i l l have to be i n s t a l l e d i f u n i t i s being used continuously. (d) Monetary Cost and Energy Requirements A 1976 p r i c e l i s t i s included to i n d i c a t e d e t a i l s of cost. The B r i t i s h Columbia d i s t r i b u t o r advises that the p r i c e of Package No. 2 i s $1176.00, plus p r o v i n c i a l sales tax, F.O.B. Portland, Oregon. A p r i c e reduc-t i o n of 20-30% f o r orders of more than t h i r t y - f i v e u n i t s i s p o s s i b l e . I n s t a l l a t i o n costs are t y p i c a l l y around $50 f o r materials. Toa-Throne i s guaranteed against defects i n function, provided that the u n i t i s i n s t a l l e d and operated i n accordance with the I n s t a l l a t i o n Manual. The v e n t i l a t i o n fan draws 43 watts, or about 0.01 kwh per day when used continuously. Energy required f o r the heating element w i l l depend on l o c a l c l i m a t i c conditions. (e) Performance i n E x i s t i n g I n s t a l l a t i o n s Very l i t t l e performance data could be obtained f o r the Toa-Throne, most l i k e l y because of i t s r e l a t i v e l y recent appearance. The data from the Norwegian t e s t s are presented at the end of t h i s appendix, but should be viewed with some caution as i t appears the design has changed since then. Toa-Throne's promotional brochure states that Oregon has approved " l i m i t e d usage" of the Toa-Throne system, and i t i s among the composting t o i l e t s whose performance w i l l be monitored i n Oregon's program; however, r e s u l t s from t h i s program cannot be expected f o r a year or so at l e a s t . (f) O v e r a l l Evaluation There i s some uncertainty about how Toa=Throne w i l l a c t u a l l y perform, r e s u l t i n g from i t s attempt to combine des i r a b l e features of large and small t o i l e t s . I t s capacity i s rated at f o u r - s i x persons, which i s approximately equal to that of the C l i v u s , although i t only has one-quarter the volume, and to Humus-Toilet, although i t (usually)operates without a heating element. 107 ENVIROSCOPE TOA-THRONE AEROBIC DECAY TOILET SYSTEM PRICE LIST • Price Package # 1 - Simplest Installation, using no electricity, with toilet seat directly on container $ 845.00 Shipment consists of: Decay container top with inspection door and bottom with removal door and air staircase, distribution conduits and toilet seat and lid. Package #2 - Bathroom Installation, using electricity. Shipment consists of: Same items as above, plus Commode with insert, connecting pipe (length, 3 ft.-), ventilator cover and case, ventilator with motor. $1. 045.00 Part No. PARTS LIST Price 1-01 1-02 1-03 1-04 1-05 1-06 1-07 1-08 Decay Container - top Decay Container - inspection door (fits in top) Decay Container - bottom Decay Container - removal door (fits in bottom) Air Staircase Decay container mosquito nets (set of 6) Distribution Conduits (set of 3) Toilet seat & lid with brackets $ 406.00 11.00 456.00 29.00 48.00 11.00 13.00 13.00 2-01 2-02 2-03 2-04 2-05 Toilet Commode - without insert Toilet commode Insert Connecting Pipe (length 3 feet) Ventilator Cover and Case Ventilator with Motor 99.00 34.00 45.00 36.00 56.00 3-01 Removal Shovel 7.00 Prices: Subject to change without notice. Quoted F.O.B. Los Angeles, CA; Portland, OR; Seattle, WA; Minneapolis, MN; Boston, MA . Terms: 30% with order, balance prior to shipment. 11/76 Toilet addrata Otfica Cabla A d d r m T«taphon« fO Bo« 761 28S5 E. Coait Highway ENVIRO Corona dal Mar, California 92625 714/673-7774 108 The smaller s i z e w i l l permit better use of heat generated by the decompos-i t i o n , but aeration by the a i r s t a i r c a s e i s also stressed as a major f a c t o r i n promoting rapid decomposition, and t h i s would tend to have a counter-v a i l i n g c o o l i n g e f f e c t . This suggests that a d d i t i o n of a heating element may not be a l l that unusual. Another source of uncertainty i s the slope angle. I f i t is_ 41°, then there i s the increased r i s k of f r e s h l y deposited material "bouncing" o f f the p i l e and r o l l i n g down to the f a r end. There i s also the p o s s i b i l i t y of urine draining too quickly to the lower end; the Norwegian study i n f a c t warns about slopes i n excess of about 2 0 ° . As p o s s i b l e confirmation , one • of the few maintenance a c t i v i t i e s that the i n s t a l l a t i o n manual advises i s to check f o r urine at the lower end. This suggests that a v e n t i l a t i o n fan w i l l l i k e l y be necessary f o r optimum evaporation of l i q u i d , and that Toa-Throne may be more s e n s i t i v e to underloading i n the i n i t i a l period than i s C l i v u s . In conclusion, Toa-Throne i s l e s s r e s i l i e n t than Clivus-Multrum, but more so than the s m a l l , e l c t r i c t o i l e t s . The key i s again the s i z e , and i t i s s i g n i f i c a n t that the 'Good'rating i n the Norwegian te s t was given to a la r g e r model. I f a heating element i s required, the e f f e c t i s that of a large, e l e c t r i c t o i l e t . Toa-Throne has the advantage of being l e s s c o s t l y and more e a s i l y i n s t a l l e d than the C l i v u s . On the other hand, i t probably requires more c a r e f u l attendance and i s more s e n s i t i v e to changes i n loading. There i s also the p o s s i b i l i t y that i t s use w i l l be r e s t r i c t e d more often than w i l l the C l i v u s ' use because of lack of e l e c t r i c a l power. In essence, there i s more uncertainty about the Toa-Throne than about Clivus-Multrum i n r e l a t i o n to how they perform i n ac t u a l as w e l l as test i n s t a l l a t i o n s . This uncer-t a i n t y w i l l only be removed as a c t u a l performance r e s u l t s become a v a i l a b l e . SMALL, ELECTRIC TOILETS As mentioned i n the text, the f u n c t i o n a l s i m i l a r i t y among small t o i l e t s i s the way they compensate for the s i z e reduction: they have e l e c t r i c heating elements to provide temperature c o n t r o l and to evaporate urine; they have e l e c t r i c fans to ensure adequate aeration and v e n t i l a t i o n ; and they u s u a l l y have mechanical devices to s t i r the material and/or d i s t r i b u t e i t evenly wi t h i n the chamber, and these may be manually or e l e c t r i c a l l y operated. The net e f f e c t i s to increase the rate of decomposition and decrease the time of r e t e n t i o n of matter i n the chamber 109 HUMUS-TOILET Humus-Toilet i s manufactured i n Sweden by Sanitat i o n AG, where i t i s c a l l e d Mulltoa. It i s d i s t r i b u t e d i n Canada by Future Eco-Systems Ltd., 680 Denison Street, Markham, Ontario L3R 1C1; and i n B r i t i s h Columbia by ATCO Leasing, 18646 96 Avenue, Surrey, B.C. V3P 4Y4. In the very near future, the t o i l e t w i l l also be manufactured i n Ontario. The p a r t i c u l a r model to be discussed i s the H-10. (a) Design and Phy s i c a l C h a r a c t e r i s t i c s '3 12 1. Two mould boxes 2. Mould box cover 3. C e l l u l o s e t i s s u e mat 4. S l i c e i r o n o u t l e t 5. R e c i r c u l a t i o n system 6. L e v e l l e r 7. Trap 8'. Trap handle 9. Funnel 10. T o i l e t seat 11. T o i l e t seat cover 12. Hygrometer 13.,Air o u t l e t c o n t r o l 14. V e n t i l a t i o n pipe o u t l e t 15. Thermostats 16. Heaters 17. Screen 18. Fan FIGURE 6: HUMUS-TOILET (model H-53) Sp e c i f i c a t i o n s : (model H-10) Materials - s h e l l i s constructed of impact r e s i s t a n t , moulded polyethylene Width - 62 cm Length - 100 cm Height - 74 cm Weight - 35 kg Of p a r t i c u l a r i n t e r e s t i s the a i r r e c i r c u l a t i o n system. A i r i s con-s t a n t l y forced around the compost and into the mould boxes, where i t s heat and humidity maintain proper conditions f o r decomposition and mineralizaton. This r e c i r c u l a t i o n of a i r reduces energy consumption by the heating element and r e s u l t s i n a lower volume of a i r being evacuated compared to other t o i l e t s with a fan. 110 (b) Capacity The H-10 can accommodate four persons on a continuous b a s i s , or s i x persons on a seasonal b a s i s . When used i n i n d u s t r i a l a p p l i c a t i o n s , i t can handle nine persons on a 12-hour s h i f t basis or f i f t e e n persons on an 8-hour s h i f t b a s i s . Overloads of short duration can be accommodated. About a k i l o -gram of humus i s removed about once a year when the t o i l e t i s i n continual use, or l e s s often f o r intermittent use. The H-10 can adequately decompose only l i g h t grades of t o i l e t paper; bones and heavy paper should be excluded, i n f a c t the manufacturer recommends addi t i o n of only those items "that a small p i g could eat". ' (c) I n s t a l l a t i o n and Management Requirements The t o i l e t can be i n s t a l l e d d i r e c t l y on the bathroom f l o o r or i n some other room. The only requirement f o r space other than f o r the t o i l e t i t s e l f i s an area Of 65 x 152 cm to enable operation of the s l i c e i r o n and removal of the mould boxes. Wherever i t i s i n s t a l l e d , adequate i n s u l a t i o n , espec-i a l l y between t o i l e t and f l o o r , should be added to minimize heat l o s s . I t may be necessary to heat incoming a i r i f t o i l e t i s not i n s t a l l e d i n a warm room. The v e n t i l a t i o n system i s c r i t i c a l ; one i s a v a i l a b l e at extra cost and i n f a c t must be used to maintain warranty. In col d climates, e s p e c i a l l y the A r c t i c , the v e n t i l a t i o n pipe must be wrapped with e l e c t r i c tape on the outside of b u i l d i n g s . , The t o i l e t comes with a bag of peat moss and a bag of s p e c i a l l y -prepared humus s o i l . The s t a r t e r bed i s prepared by spreading the peat moss to a depth of 5cm evenly over the paper-covered screen above the mould boxes. Then the humus s o i l i s spread over the peat moss, with care taken to leave the bed as l o o s e l y packed as po s s i b l e to ensure optimum a i r c i r c u l a t i o n . Operating requirements f o r the Humus-Toilet include several regular a c t i v i t i e s r e l a t i n g to maintaining optimum conditions f o r decomposition. An external a i r o u t l e t c o n t r o l i s provided to regulate moisture content i n the chamber as measured by a hygrometer. When the hygrometer i n d i c a t e s excess moisture, the a i r c o n t r o l i s opened to allow more air/moisture to escape. When i n s u f f i c i e n t moisture i s i n d i c a t e d , the a i r flow i s reduced, and i f the condition p e r s i s t s , water must be added. Moisture c o n t r o l requires more or l e s s constant supervision, e s p e c i a l l y i n hot, dry weather conditions. I l l Another a c t i v i t y which should be performed d a i l y i s the operation of t h e l e v e l l e r a f t e r each or several uses i n order to ensure even d i s t r i b u t i o n of the excreta. On a s l i g h t l y l e s s frequent b a s i s , the use of the s l i c e i r o n i s impor-tant i n order to permit proper a i r c i r c u l a t i o n through the compost. A f t e r the p i l e has reached almost up to the l e v e l l e r bar, the s l i c e i r o n must be insert e d once a week and used to break up clods and rake material down to the lower l e v e l . I t i s of course necessary to wash t h i s t o o l a f t e r each use. F i n a l l y , i t i s necessary to p e r i o d i c a l l y add new microbes to the Humus^ -T o i l e t to speed up the decomposition process.Kitchen scraps such as vegetable peelings can be used, but i t i s also recommended to add a few handfuls of f r e s h l y cut grass c l i p p i n g s once or twice a month. When grass or other organic garbage i s not a v a i l a b l e , as i n i n d u s t r i a l uses, extra humus s o i l can be purchased from the d i s t r i b u t o r and added p e r i o d i c a l l y . (d) Monetary Cost and Energy Requirement The current p r i c e of the H-10 i s $900-$929 and the v e n t i l a t i o n k i t i s an extra $63. A discount of up to 20% i s possible on orders greater than ten u n i t s . When the t o i l e t i s produced i n Canada, the p r i c e w i l l probably , be reduced. Smaller models, s u i t a b l e f o r intermittent use only, cost about $50 l e s s . The t o i l e t can use eit h e r standard l l O v or 220v, and maximum power input i s 250 watts or more. E l e c t r i c i t y i s used to operate the fan and the heating elements, the l a t t e r being t h e r m o s t a t i c a l l y - c o n t r o l l e d . Average d a i l y power consumption i s about 0.5 kwh. Energy use can be minimized by extra i n s u l a t i o n and pre-heating incoming a i r . (e) Performance i n E x i s t i n g I n s t a l l a t i o n s As i n d i c a t e d i n the text, e a l i e r models have given very u n s a t i s f a c t o r y performances. Persi s t a n t bad odour was a common problem both i n Quebec and Newfoundland[18] : i n s t a l l a t i o n s and resulted i n removal of the t o i l e t . However, the most d e t a i l e d account of problems experienced with Humus-Toilets i s the i n t e r i m report of the Manitoba Department of Northern A f f a i r s [ 4 2 ] . These problems included: f l u i d accumulation - units were e s p e c i a l l y s e n s i t i v e to urine overloading during p a r t i e s , and residents were not warned of t h i s p o s s i b i l i t y ; bad odour - a i r c i r c u l a t i o n was impaired; mechanical f a i l u r e -p r i m a r i l y burned out s t i r r i n g arm motors; uneven moisture d i s t r i b u t i o n -112 urine saturated the area immediately below the t o i l e t seat but other areas were dry, e s p e c i a l l y i n the period before enough mass had accumulated so that the l e v e l l e r could operate. The study concluded that the small s i z e requires constant a t t e n t i o n and d i s c i p l i n e d use on the part of the residents i n order to ensure proper operation. In f a c t , the only t o i l e t which performed w e l l served a three-person family and was maintained by a person very f a m i l i a r with the needs and c h a r a c t e r i s t i c s of m i c r o b i a l systems—the authors did not consider him to be a t y p i c a l user. Many of the units probably f a i l e d because of improper operation and maintenance (for instance, the report makes no mention of the weekly use of the s l i c e i r o n ) . Furthermore, the model used was one of the smaller ones. . The H-10 i s l a r g e r , s t u r d i e r , has a manually-operated l e v e l l e r and, at l e a s t i n the l o c a l area, comes with a comprehensive i n s t a l l a t i o n and op-e r a t i o n manual and i s backed up by personal service by the B.C. d i s t r i b -utor. As f o r dependability, i t appears to be performing w e l l i n northern construction camps. (f) O v e r a l l Evaluation The major f a c t o r i n favour of the Humus-Toilet i s the e f f o r t that has gone i n t o redesigning i t as a r e s u l t of the e a r l y problems. I t prob-ably has the most extensive experience i n a c t u a l use and most of the things that could go wrong, have gone wro-ifr and have led to improvements. As a r e s u l t , i t can w e l l serve as a standard against which other small, e l e c -t r i c t o i l e t s might be judged. Perhaps the only remaining need f o r design improvement i s the s l i c e i r o n . The s t i r r i n g function i s important enough that the device should be made an i n t e g r a l part of the t o i l e t , rather than something that could get l o s t or not cleaned properly. In conclusion, when Humus-Toilet i s i n s t a l l e d , used and maintained by people who understand i t s requirements and l i m i t a t i o n s thoroughly, i t w i l l provide dependable s e r v i c e . 113 MULLBANK Also known as Ecolet, the Mullbank i s manufactured i n Sweden by Inventor Miljoprodukter AB, and d i s t r i b u t e d i n Canada by Canadian Inventor Ltd., 66 Plateau Crescent, Don M i l l s , Ontario M3C 1M8. (a) Design and Physical C h a r a c t e r i s t i c s FIGURE 6: MULLBANK Unfortunately, there i s very l i t t l e information a v a i l a b l e on the Mullbank other than the very general promotional brochure. The main d i f f e r e n c e between i t and Humus-Toilet i s that the heating c o i l i s mounted h o r i z o n t a l l y and i n f a c t supports the waste mass. Thus any urine which comes down t h i s f a r i s quickly evaporated. The c o i l i s t h e r m o s t a t i c a l l y regulated. The v e n t i l a t i o n system i s very simple, c o n s i s t i n g of an a i r intake i n the bottom and a noiseless fan which sucks a i r through the mass and out the vent at the top. Other than a r o t a t i n g arm to d i s t r i b u t e f r e s h l y deposited ma t e r i a l , there does not seem to be any s t i r r i n g devices to promote aeration. 114 (b) Capacity The Mullbank i s designed for continuous use by f i v e or s i x people, and can accommodate up to f i f t e e n people on an intermittent b a s i s . It apparently can accept t o i l e t wastes only. The promotional brochure claims that a f t e r , a year of normal use, enough powder-dry, odourless residue i s removed to f i l l a "coffee can". (c) I n s t a l l a t i o n and Management Requirements The t o i l e t requires a f l o o r space of 135 x 61 cm. I n s t a l l a t i o n r e q u i r e -ments of the v e n t i l a t i o n stack are s i m i l a r to other t o i l e t s . The t o i l e t comes with peat moss f o r use as a s t a r t e r bed. According to the brochure, maintenance a c t i v i t y i s minimal, c o n s i s t i n g only of ad d i t i o n of water i f the t o i l e t Is not used for a period of two weeks or more. (One hopes that the i n s t r u c t i o n manual contains more d e t a i l ) (d) Monetary Cost and Energy Requirement The approximate cost of the Mullbank i s between $625 and $659, but these p r i c e s were quoted i n 1976, p r i o r to CSA C e r t i f i c a t i o n i n January 1977, f o r which c e r t a i n changes were made i n the materials used and i n the e l e c t r i c a l system. P r i o r to CSA c e r t i f i c a t i o n , the t o i l e t operated on 42v and needed a transformer. I t now runs on 120v and i t s average energy demand i s about 2.4 kwh/day, l e s s i n warm weather. (e) Performance i n E x i s t i n g I n s t a l l a t i o n s According to the d i s t r i b u t o r and the promotional brochure, there are over 50,000 of the t o i l e t s i n use a l l over the world, many i n Scandinavia. They have been granted approval f o r use on boats by the US Coast Guard, and anywhere e l s e where approval was sought, i t was granted. In s p i t e of a l l t h i s a c t i v i t y , though, there does not appear to be any published reports of the a c t u a l performance of the Mullbank. One of the reasons f o r the lack of data on Canadian i n s t a l l a t i o n s i s that the d i s t r i b u t o r was not a c t i v e l y promoting the t o i l e t u n t i l CSA c e r t i f i c a t i o n was obtained and the new u n i t s on the market, events which have j u s t occured within the l a s t few months Results from laboratory t e s t s are given i n the next appendix. 115 (f) O v e r a l l Evaluation The lack of information makes i t impossible to evaluate the Mullbank. It appears to be a s i m p l i f i e d version of the Humus-Toilet, but there i s no i n d i c a t i o n whether or not i t suf f e r s from any of the problems Humus-Toilet experienced. At the very l e a s t , i t should not s u f f e r from urine overloading, but at the cost of having the highest energy cost of the four t o i l e t s . An evaluation must wait u n t i l r e s u l t s s t a r t coming i n from programs l i k e the one i n Oregon. Big Toilets of sloping Floor—type 1 Type/ Model 2 Manufacturer / Importer 3 Price, approx. Nkr. 4 Dimensions above floor i n mm. Width x depth x height 5 Dimensions unde" floor i n mm. Width x depth x height . 6 Fan 7 Heating element 8 E l e c t r i c i t y consumption W 9 Number of t o i l e t seats 10 Number of tanks 11 Useful volume per tank i n l i t r e s 12 Tank-bottom angle, degree**, 13 Ventilation pipe, dia. i n mm. Id Air—speed i n vent, pipe, m/sec. 15 Air-volume i n vont. pipe, „ , l i t r e / s e c . 16 Load, No. of people 17 Load time, No. of days 18 Total load in kg. 19 Kitchen waste in kg. 20 Weight reduction during test in °f> 21 Temperature i n waste in C° 22 Intestinal bacteria, sanitation 23 Decomposition degree, visually judged 2 months after l a s t load 24 Instruction for use 25 Function, t o t a l evaluation for the test-load used Dosenten A/S HJem og Fasade, Oslo 2475:-ToilBt-chair Hakodo 700 Hakodo 1000 Halvorsen Industrier A/S Kongsberg 2475;- 3100:-Toilet-chair Toilet-cnair Kombio A/S Andstor Oslo 3600:-860x880x550 Teknisk Fiber-plast A/5 Krogstadelva 3120:-Toilet-chair Toa-1hrone Toa-Throne AB Swede ym! eSektronikkA/S Tonsberg 4700:- i n c l . fan and fan-housing Toilet-chair 780x1540x960 No 1260x1260x870 No 860x2000x1840 No 860x2050x880 No Tank dia. 1270 + oioe-end 210 height 690 No [4j 1130x1690x128 Yes No No No (3) No No (3) No - - - - - 20 1 1 1 1 1 1 1 1 1 1 4 1 12 23 30 17 - 28 160 105 160 160 160 110 0.6 0.5 0.2 0.7 0.4 2.5 12 4 4 19 8 20 6 6 6 6 4 6 47 40 47 47 34 47 400 326 400 400 208 405 7.5 7.5 7.5 7.5 7.5 7.5 61 50 42 71 56 72 20 22 21 19 19 17 Very good Good Satisfactory Very Good Good Satisfactory Sad Bad Bad Satisfactory Satisfactory Satisfactory Satisfactory Bad Bad Good Bad Gcod Bad Bad Bad Good Bad Good 1 Type / Model 2 Manufacturer / Importer 3 Price, aporox. Nkr. •^Dimensions above f l o o r i n mm. Width x depth x height 5 Dimensions under floor i n mm. Width x depth x height 6 Fan 7 Heating element 8 E l e c t r i c i t y consumption W 9 Number of t o i l e t seats 10 Number of tanks 11 Useful volume per tank i n l i t r e s 12 Tenk-bottom angle, degrees 13 V e t i l a t i o n pipa, dia. i n mm. Id Air-speed i n vent. oiDe, m/seo. 15 Air—volume i n vent, pipe, i c i > >• _ , l i t r e / s e c . 16 Load No. of people 17 Load time, No. of days 18 Total load i n kg. 19 Kitchen waste i n kg. 20 Weight reduction during test i n 21 Temperature i n waste in C° 22 Intestinal bacteria, sanitation 23 Decomposition degree, v i s u a l l y judged 2 months after l a s t load 24 Instructions f o r use 25 Function, t o t a l evaluation for the test-load used Small t o i l e t s with e l e c t r i c heating element Bio-do. Bioloo (s) G ustavsbergs Brodr. StenerudFabriker AB Sw. Fabrikker A/S Porsgrunds-Namdalseid Gustavsborgs Oslo 2950:- 3000:-610x990x680 620x300x630 Yes Yes 250 1 1 KPS M i l j o - , Ecolet klosett[MK-73) R E i C ,K. Pettersens Sonnor Sarpsborg 2500:-580x1050x750 Mull-toa Mull-toa Jumbo 24"x42"x32" 'UP0 Dy. Finland A/S UPO, Oslo Yes Yes (6) 50 + pasteur. element 180 1 75 110 1.5 2.5 6.5 18 4 4 43 46 220 232 7.5 7.5 $ 7 2 85 26 55 Satisfactory Vary Good Good Good Satisfactory Satisfactory Bad Bad (7) * Sinco completion of study, 2950:-540x770x710 3550:-610x1000x760 - — ** Heating-coil Yes Yes Yes Yes (B) Yes Yes Yes 2B0 160 180 225 1 1 - 1 1 1 1 1 1 - — 75 110 50 50 1.0 2.0 4.5 3.5 4 16 9 7 4 4* 4 6 48 48 48 48 260 260 260 370 7.5 7.5 7.5 7.5 75 83 91 85 22 22 22 26 Good Vorv Good Very Good . Satis Good Good Good Good Good Good Good Good Satisfactory Good Satisfactory Good modification of unit Increases Load of People to 6 118 APPENDIX B: CHEMICAL AND BIOLOGICAL ANALYSES OF COMPOSTING TOILET END PRODUCT TOA-THRONE The following data are taken from the a r t i c l e by Lars DeJounge, the president of Enviroscope, i n Compost Science[12]. No source was given f o r the chemical a n a l y s i s , but the b i o l o g i c a l a nalysis was taken from the study done by the Norwegian A g r i c u l t u r a l College[AO]. Normal End Product of Complete Composting with Toa-Throne Consists of Approximately the Following: Dry Substance Humus : Nitrogen Ammonium N i t r a t e s Phosphorus Calcium The b i o l o g i c a l a n a l y s i s was c a r r i e d out by i n o c u l a t i n g the chamber with Salmonella, p o l i o v i r u s and EschierLchia and then t e s t i n g the m a t e r i a l i n the chamber at vatying times a f t e r contamination: Both salmonella and p o l i o v i r u s counts were ' n e g l i g i b l e ' a f t e r approximately one week, one month and two months. Approximately one week a f t e r loading, E s c h i e r i c h i a showed 1000 - 10,000 MULLBANK The data on the following page comes from a test performed by the Water, Drainage and Sewage Section of the French M i n i s t r y of P u b l i c Health, the r e s u l t s of which were presented by Doctors Coin and Lagarde on May 7, 1973. 45 % 40 1 pH : 7.0 - 8.5 0 2 5 C/N: 15 - 20 .8 E- C o l i 0 - 100 (per gram) 1.5 119 F i n a l l y we also requested that we should be sent compost samples f r o m installations in Sweden and taken f r o m the c o l l e c t i n g trays of units which had been in use for s e v e r a l months. These samples, re c e i v e d On 14/2/73, were f r o m apparatus units which had been i n use for 3, 6 and 9 months r e s p e c t i v e l y . The results of the bacteriological, c h e m i c a l and p a r a s i t i c tests were as follows: M U L L B A N K in use f o r 3 months 6 months 9 months E s c h e r i c h i a c o l i ( per 1 0 0 g waste) 2 4 0 , 0 0 0 0 0 C o l i f o r m 4 6 0 , 0 0 0 3 6 0 1 , 5 0 0 F a e c a l streptococci * 2 4 0 , 0 0 0 2 , 1 0 0 3 6 0 pH value 6 . 1 6 . 8 6 . 8 D r y substance('7o) 8 8 8 9 9 2 M i n e r a l substance ( % dry substance) 3 2 5 3 4 6 Organic substance ( % dry substance) 6 8 4 7 5 4 T o t a l n i t r o g e n ( % dry substance) 2 . 8 9 1 . 5 6 2 . 3 4 Carbon/Nitrogen 1 2 . 5 1 2 . 8 1 0 . 3 Phosphorus ( P % dry substance) 0 . 8 5 1 . 7 1 . 9 P o t a s s i u m ( K % dry substance) 2 . 1 3 . 1 2 . 7 C a l c i u m ( C a % dry substance) 0 . 6 1 . 5 1 . ) P a r a s i t i c examination Negative Negative Negative These results are very s i m i l a r to those obtained in a l a b o r a t o r y of the Roya l Swedish A g r i c u l t u r a l College h U P P S A L A concerning samples f r o m installations which had been in use for corresponding p e r i o d s . CLIVUS-MULTRUM (Source for this data i s Lindstrom[37]) The Clivus-Multrum System Table l a Composition of Contents of Compost Reactor Receiving Human Organic Waste for Eight Years pH = 7.6 Ashes = 63.0% "Humus" = 23.7% Rest 13.3% (essentially water) Conductivity 92 Volume weight 735 gms/liter Mg/litcr Percentage Ca 2 * 14000 1.9 K* 8200 1.12 B 4.2 Cu 32 0.044 Mn 145 0.020 Mg 960 0.13 P total 3700 0.50 Ntotal 0.84 N i n N H , 1150 0.1 B N in N 0 2 3200 0.44 N i n N 0 3 960 0.13 Cl 350 0.05 s o 4 J " 650 0.00 A l * 3 dissolvable in H'CL 0.87 'Analyses made by Markkarte Ringsljanst, Helsinki, Finland. Table 2 Corresiionding Oxides and NH 3 Values of the Main Constituents given in Table 1 CaO 2.6C K j O 1.35 M „ 0 0.22 N 2 J O s 0.60 N 2 0 3 1.19 A l 20 3 l.u8 P 2 O s -1.15 N H 3 _1J>4 Total 10.79 121 The material which s t a r t s below i s taken from an exhaustive analysis of the b a c t e r i a l populations i n the C l i v u s ' end product c a r r i e d out by the Center f o r the Biology of Natural Systems[43]. "Table 1" on page 121 i n d i c a t e s the range of samples that were analyzed. I t i s i n t e r e s t i n g to note that two of the samples were l i q u i d taken from f i n i s h chamber. The r e s u l t s bear out statements made by Clivus-Multrum USA, Inc. to the e f f e c t that the l i q u i d that accumulates i n the lower p o r t i o n of the chamber during the break-dn period i s not a health hazard. This i s i n contrast to the statement i n the Manitoba report, however[see page 96]. B. Summary o f r e s u l t s 1. A s e r i e s o f f i n a l products from e s t a b l i s h e d Multrums i n Sweden, incomplete products frorri two r e l a t i v e l y new Multrums i n the U.S., and a sample o f Swedish garden compost have been a n a l y z e d w i t h r e s p e c t t o t h e i r b a c t e r i a l p o p u l a t i o n s . The numbers o f c o l o n y - p r o d u c i n g b a c t e r i a p r e s e n t i n each sample have been e s t i m a t e d by means o f c o l o n y counts on n u t r i e n t p l a t e s p r e p a r e d from s e r i a l d i l u t i o n s o f the samples i n c u b a t e d a t 37°C under both a e r o b i c and a n a e r o b i c c o n d i t i o n s . In each sample, the c o l o n y - p r o d u c i n g b a c t e r i a were i d e n t i f i e d , g e n e r a l l y t o the l e v e l o f s p e c i e s , by means of a s e r i e s o f s t a n d a r d s t a i n i n g and b i o c h e m i c a l t e s t s . 122 2. The numbers and types of b a c t e r i a found i n the samples of Multrum f i n a l product are s i m i l a r to those that are known to occur i n s o i l s , except f o r the presence of a s i g n i f i c a n t number of Lactobacillaceae i n c e r t a i n Multrum samples and the absence of s i g n i f i c a n t numbers of Cornybacter- iaceae from a l l Multrum samples. The low count of Cornybacter- iaceae i s to be expected since the culture plates used to t e s t the samples were incubated at 37°C, which i s well above the optimum temperature f o r the growth of these b a c t e r i a , and also because of the elevated temperatures occurring i n the Multrum i t s e l f . The elevated population of Lactobacillaceae, b a c t e r i a that occur t y p i c a l l y i n milk, i n c e r t a i n of the samples probably r e f l e c t s a predominance of dairy products i n the d i e t of the users o f these Multrums. 3. By f a r the most predominant b a c t e r i a l family i n the Multrum samples was the Bacillaceae, a family that i s luore p l e n t i f u l than any other, except f o r Cornybacteriaceae, i n s o i l s . Although one genus of t h i s family, Clostridium, contains many pathogens, the C l o s t r i d i a found i n the Multrum samples were predominantly members of the non-pathogenic s a c c h a r o l y t i c group. No pathogenic species of C l o s t r i d i a were i d e n t i f i e d i n Multrum samples. 4. The pathogenic b a c t e r i a found i n Multrum samples* are species that are also known to occur widely i n s o i l . The numbers of colonies of pathogenic b a c t e r i a , r e l a t i v e to the t o t a l number of colonies, were quite l o w — l e s s than two percent. 123 5. Escherichia- c o l i , the indicator species for f e c a l contamination was not found i n any Multrum samples^ 6. The range of values for the r a t i o of aerobic to anaerobic organisms was s i m i l a r to that observed i n s o i l s , suggesting that the Multrum compost, l i k e s o i l , i s moderately aerobic. 7. Although the samples were taken from Multrums which had been established f o r varying lengths of time (ranging from 3 to 23 years), and from the material i n the f i n i s h i n g chamber as well as from i n s i d e the Multrum, the character of the b a c t e r i a l population was s i m i l a r from sample to sample. The t o t a l numbers of colonies, which varied between 31 and 454 per 10"^ gm showed no consistent r e l a t i o n s h i p to the age or l o c a t i o n of the Multrum. 8. The numbers and types of b a c t e r i a found i n a sample of Swedish garden compost were s i m i l a r to that found i n the Multrum samples. IV. Conclusions * On the*basis of the r e s u l t s of t h i s i n v e s t i g a t i o n we conclude that: A. The b a c t e r i a l composition of the f i n a l Multrum product i s s i m i l a r to that of s o i l . B. The pathogenic p o t e n t i a l of the f i n a l Multrum product, i . e . , the numbers and species of pathogenic b a c t e r i a present, i s s i m i l a r to that of s o i l . 124 C. The M u l t r u m f i n a l p r o d u c t a p p e a r s t o be s u i t a b l e f o r u s e as a s o i l amendment. * * * 125 TABLE 1 D e s c r i p t i o n o f Samples Sample No. A B D H K M N D e s c r i p t i o n Garden compost F i n i s h e d m a t e r i a l f r om M u l t r u m F i n i s h e d m a t e r i a l from M u l t r u m F i n i s h e d m a t e r i a l f r om M u l t r u m F i n i s h e d m a t e r i a l from M u l t r u m F i n i s h e d m a t e r i a l from M u l t r u m F i n i s h e d m a t e r i a l from M u l t r u m F i n i s h e d m a t e r i a l f r om M u l t r u m . M a t e r i a l f r om l o w e r garbage chamber o f Multrum M a t e r i a l from l o w e r garbage chamber o f Multrum S o i l f r o m f i n i s h chamber o f M u l t r u m S o i l f r o m f i n i s h chamber o f M u l t r u m L i q u i d f r om f i n i s h chamber of M u l t r u m L i q u i d f r o m f i n i s h chamber of M u l t r u m L o c a t i o n Sweden (outdoor) Sweden (outdoor) Sweden ( i n d o o r ) Sweden (outdoor) Sweden ( i n d o o r ) Sweden ( i n d o o r ) Sweden ( i n d o o r ) Cambridge, Mass. ( i n d o o r ) H o p k i n g t o n , N.H. ( i n d o o r ) Cambridge, Mass. ( i n d o o r ) H o p k i n g t o n , N.H. ( i n d o o r ) Cambridge, Mass. ( i n d o o r ) Cambridge, Mass, ( i n d o o r ) Date o f I n s t a l l a t i o n 1944 1963 1963 1969 1969 1970 . 1971 March 1973 S e p t . 1972 March 1973 Sept. 1972 March 1973 March 1973 APPENDIX C: OWNER-BUILT COMPOSTING TOILETS/PRIVIES The designs on the following pages are taken from Stop the Five  Gallon Flush!, published by the Minimum Cost Housing Group at M c G i l l U n i v e r s i t y School of Architecture[50], who are also the reference f o r the "Cli v u s Minimus". .CIIVUS The container the Clivus Min-fabricated-from for imus was standard size cement blocks. These were Joined together by lay-ing up dry and surface bonding with a molten mixture of sulphur, f i b r e g l a s s and dicyclopentadeine. This waterproofs as well. A more conventional method would be to lay the blocks in mortar and waterproof with bitumen. It i s important to maintain a slope of 30°, and to seal the unit completely. This i s done with mosquito netting at the a i r input and ven t i l a t i o n exhaust. The v e n t i l a t i o n pipe ought to be b u i l t as t a l l as possible.The exact nature of the ducts w i l l depend on the a v a i l a b i l i t y of materials, but these must be non-corrosive ( aluminum gutters, p l a s t i c drainage pipes, f i b r e g l a s s or asbestos-cement). In cold climates such a mouldering t o i l e t should be i n -s t a l l e d i n a heated basement. Even i f the t o i l e t were in-clated, cold ex-t e r i o r a i r would seriously affect operation in an exterior location. 128 J^KERN COMPOST PRIVY Designed by: Ken Kern P.O.Box 550 Oakhurst California 93664, USA Reference: The Owner-Built Homestead by Ken Kern 1974 DECOMPOSITION 1. Compost Privy This i s a design that was f i r s t published in "The Owner-Built Home" and has subsequently, with modifications, been built by Ken. It i n -corporates a sauna and water heater on the upper level, and a shower and toilet on the lower floor. The composting chamber, below the floor, i s divided i n two compartments. A metal baffle directs the waste from one to the other, and C07APOST PR.lVy CO/JSTR.OCTIOW o t T A t u 2.">«>>>l.4TIOM 56 twice a year alternate compartments are cleared of compost. The compost nay have to be turned by hand from, time to time. The water from bathing and washing is diverted from r the toilet and separately carried to a t i l e f i e l d . The f i f t h , and latest prototype built by Ken Korn incorporates an anaerobic chamber below the compost chamber, for handling the washing wat-er and urine overflow *rom the. compost. This design, which is not shown, utilizes a circular slip-form and concrete construction. C O M P O S T CHAAMiE.R. T O I L E T - W A S M N t o *h\Hir*b 129 >JC FARALLONES PRIVY DECOMPOSITION 1. Compost Privy Designed by: FaraHones I n s t i t u t e Point Reyes Station C a l i f o r n i a 94956, USA . Cost: under $100.00 Plans ava i l a b l e from above address for $1.50 postpaid. This do-it-yourself t o i l e t i s most suitable f o r a r u r a l loc-a t i o n , both because of i t s area, and the operation (the manure requires to be turned once a month). Simple and cheap. A number of these have been installed in northern California. An little urine as possible should he introduced into the composting chamber} and with good management this model seems to be working out well. 'TrOK ONE TrAJAlisi' f - t C J T V ^ U - T C I A N P » & u i u c T H E < t i u <f-see L-^ r /AA .TEPJA1- 0 > 5 T : L-e^S "THAN ? | o C CAN & & pe-TActHE^P' O U T H « J ^ e C R . r ^ ^ ^ ^ 1 racoon 1 SH'TTfWJSrrf i W I T H <nrv>w i.wmA U^tCa MOMTVIfl., Move P I L C T C T CAJP-S> Here, p.e/j IVT fur- KAcir-OR. X > I A £ J i A M L 130 APPENDIX D: GREYWATER PRE-TREATMENT FILTER The design on the following pages i s s t i l l i n the developmental Stages, with Clivus-Multrum USA asking f o r feedback from people who purchase one of the u n i t s . For information on the r e s u l t s to date, contact the company d i r e c t l y . Although the diagram shows the f i l t e r hooked up to a leach f i e l d , another use f o r i t would be to pass greywater through i t p r i o r to sending the greywater to a greenhouse. 131 TIIK CLIVUS MULTRUM WASHWATKR ROUGHING FILTER This washwater treatment system is designed to protect leach pipes from clogging, by straining out larger particles ;«nd fibers, such as hair, lint and food wastes from all non-toilet sources in the home. DESCRIPTION OF PROCESS Straining is accomplished by seepage through a gravel bed contained in a cone-shaped fiberglass tank installed in the basement of the home. The wastewater enters the cone at its top, passes by gravity through the gravel bed, and leaves the cone through its bottom, to then pass to the leaching field, either by gravity or by pressure created by a pump installed in the effluent line. By removing large particled solids and hair and lint, this filter permits the use of smaller diameter pipe to channel washwater to the leach lines, and also protects the leach lines from clogging. Clogging of pipes, and especially their distri-bution holes, is principally a biological process. However, the biological growth needs physical support in order to resist hydraulic pressure. The straining process inhibits fibers or larger particles from forming that reinforcement in and around the leach line holes. The gravel bed will also serve to catch, de-emulsify and degrade some of the grease in washwater, particularly in kitchen sink wastes. (Where a Multrum is installed, this grease is preferably placed in the composter, not the washwater.) CAPACITY AND SIZE The cone's diameter at the top is 48", at the bottom 8". The vertical height of the cone is 48" and additional height must be allowed for " T " fittings at the effluent line beneath the cone. This cone provides capacity well above the maximum flow levels of washwater from single family dwellings even where dishwashers and automatic clotheswashers are in service. Overflows which might occur under extraordinary conditions of use would only, cause washwater to pass directly into the leaching lines (by-passing the graver bed) — basement flooding would not result unless the pump (if one is used) or its electrical ne. vice faili;. INSTALLATION Clivus Multrum provides the cone, pump, delay timer, sump float switch, center pipe and cone cover. The owner must obtain locally: all pipes and fittings, crushed stone or gravel, (approximately one third of a cubic yard of 1" crushed rock or gravel) and electrical wiring. Installation is the responsibility of the owner, and Clivus Multrum will provide written installation instructions and advice. PRICE AND DELIVERY Prices are F O B , Ellsworth, Maine Cone, base and cover, with internal pipes installed Pump (!4 h.p. Teel centrifugal laundry trap) Delay timer (Dayton 6X153 slow release tinier) Sump float switch (Pcnn sump float switch, 2 pole 4X173) $300.00 50.00 40.00 8.00 Clivus Multrum USA, Inc. UA KI.IOTSTI{I.KT,CAMBUII)C;I:, MASS.OIIJS • (6n>491-5820 W H Y A TRICKLE FILTER? W H Y NOT USE A SEPTIC TANK? 132 » ACCESSIBILITY. The roughing filter, installed in the basement, will not require professional pump out service. • MORE ADEQUATE PRE-TREATMENT. Because aerobic conditions prevail within the gravel bed, aerobic micro-organisms are passed to the leaching field. Anaerobic micro-organisms, fa-vored by septic tank conditions, are smaller in size and tend to clog up the pores of the soil at the interface with the leaching lines. • EASE AND ECONOMY OF INSTALLATION. No excavating with heavy equipment is required as with septic tanks. The filter is light and easily handled. • COST SAVING. The installed cost of the trickle filter will be considerably less than a septic tank. • HEAT RECOVERY. Heat from the washwater (lost when flushed into an outdoor septic tank) remains within the home. 133 APPENDIX E; REGULATORY GUIDELINES FOR COMPOSTING TOILETS Beginning on the next page are the guidelines adopted by the Washington State Department of S o c i a l and Health Services f o r the use of composting t o i l e t s i n general. Following t h i s on page 133 are the B r i t i s h Columbia Administrative C i r c u l a r s dealing with the approval of Humus-Toilet. > 134 GUIDELINES GOVERNING THE DESIGN, APPLICATION AND OPERATION OF COMPOSTING TOILETS September 16, 1975 I. Introduction The Technical Review Committee f o r On-Site Sewage Disposal, e s t a b l i s h e d under WAC 248-96-046, has reviewed the a v a i l a b l e l i t e r a t u r e on composting t o i l e t s . Based upon t h i s review which included d e t a i l e d discussions with manufacturers, the Committee determined that composting t o i l e t s could be an approved method of sewage treatment i f use i s consistent with the guidelines contained herein. Composting t o i l e t s are not designed" to handle the t o t a l waste water volume generated i n the home. The units are only designed to accommodate f e c a l and urinary wastes together with small amounts of organic kitchen wastes. The remaining waste water o r i g i n a t i n g from bathing f a c i l i t i e s , sinks and washing machines (gray water) must therefore be c o l l e c t e d , treated and disposed of i n an approved manner. Since there generally would be a d d i t i o n a l waste water to dispose of, the devices should be r e s t r i c t e d to the conditions and l o c a t i o n s s p e c i f i e d below. Any device that stores and t r e a t s to compost non-water c a r r i e d human urine and feces by b a c t e r i a l aerobic d i g e s t i o n together with the necessary venting, p i p i n g , e l e c t r i c a l and/or mechanical components thereof. A. The units may be used to replace p r i v a t e p r i v i e s or chemical I I . Composting T o i l e t s Defined I I I . Process A p p l i c a t i o n t o i l e t s . (Examples: highway weigh s t a t i o n s , warehouses, port f a c i l i t i e s , construction s i t e s , etc.) B. The u n i t s may be used i n e x i s t i n g dwellings where water under pressure i s not provided. (Example: mountain cabins.) C. The u n i t s may be used i n dwelling u n i t s where an approved on - s i t e sewage system i s or can be provided f o r d i s p o s a l of gray water. D. The u n i t s may be used i n f a c i l i t i e s where a p u b l i c sewage system i s provided f o r d i s p o s a l of gray water. General Design A. S t r u c t u r a l Considerations: 1. Materials - A l l materials used must be durable, e a s i l y cleanable and impervious to strong a c i d or a l k a l i n e s o l u t i o n . Examples of such m a t e r i a l are styrene rubber, P.V.C. f i b e r g l a s s or equal. 2. S t r u c t u r a l I n t e g r i t y - The design must demonstrate adequate resistance to i n t e r n a l and external s t r e s s e s that can be a n t i c i p a t e d i n the t y p i c a l use s i t u a t i o n . B. R e l i a b i l i t y and Perfomance. A l l mechanical and e l e c t r i c a l components should be designed'to operate s a f e l y and be capable of providing continuous s e r v i c e under reasonably foreseen conditions such as extremes i n temperature and humidity. The devices s h a l l be capable of accommodating f u l l or part-time usage. C. Venting. Continuous p o s i t i v e v e n t i l a t i o n of the storage or treatment chamber must be provided to the outside. V e n t i l a t i o n components s h a l l be independent of other house-hold venting systems. Venting connections s h a l l not be made to room vents or to chimneys. A l l vents s h a l l be designed to prevent f l i e s and other insects from entering the t r e a t -ment chamber. . V. Maintenance and Operation A. A l l manufacturing of composting t o i l e t s s h a l l provide a maintenance and operation manual which should be followed. The document s h a l l contain d e t a i l e d i n s t r u c t i o n s on proper operation and maintenance procedures i n c l u d i n g s afety, a replacement parts l i s t and public health considerations. B. Removal and di s p o s a l of composted materials s h a l l be done i n a manner approved by the l o c a l health departments and as a minimum s h a l l comply with Guidelines for Sludge Disposal, Washington State Department of Health, 1954. C. N o t i f i c a t i o n of. the l o c a l health department s h a l l be made immediately i f f o r some reason the u n i t s f a i l to f unction properly. VI. Miscellaneous Non-water c a r r i e d sewage treatment units are presently not acknowledged to be an approved method of sew^go di s p o s a l under the Uniform Plumbing Code. Variances to use the devices must be granted by l o c a l administrative a u t h o r i t i e s f o r b u i l d i n g and plumbing departments. Variances must therefore be obtained from these departments together with approval of the l o c a l health department before the i n s t a l l a t i o n can be allowed. APPROVED AND ADOPTED BY THE TECHNICAL REVIEW COMMITTEE FOR ON-SITE SEWAGE DISPOSAL AT THEIR SEPTEMBER 16, 1975 MEETING. 137 Number # . "IS." flj Administrative Circular || 0a:, 5f •_• :-! = A!_~ ; - i S S A N C H ' ' " t&?&£&^^ November 19, 1974 T O : A l l H e a l t h Ur.it D i r e c t o r s FROM: D/L.K.S. Vancouver H e a l t h Departments C a p i t a l R e g i o n a l D i s t r i c t Consaunity H e a l t h S e r v i c e s Re: L i t t l e John Combustion T o i l e t and Kuraus T o i l e t We have had soma e n q u i r i e s from H e a l t h U n i t s and a r e p l e a s e d to o f f e r t h e f o l l o w i n g comments on the L i t t l a John Combustion U n i t : - . 1. Mr. B a i l e y and Hr. S c o t t examined a L i t t l e J o h n Combustion t o i l e t and c o n s i d e r i t s u i t a b l e f o r use i n campers, t r a i l e r s , h o u s e b o a t s , and i s o l a t e d s u m e r c o t t a g e s where r u n n i n g w a t e r i s u n a v a i l a b l e . 2. I t would be unwise to c o n s i d e r the L i t t l e J o h n as a s u i t a b l e means of h o u s e h o l d sewage d i s p o s a l i n t h e development o f a s u b d i v i s i o n . 3. Propane o r n a t u r a l ' g a s i s used and the t o i l e t c an s e r v e t h e d a i l y r e q u i r e m e n t s o f up to 16 pe o p l e o r 60 uses p e r day. 4. The t o i l e t has the Canadian Gas A s s o c i a t i o n a p p r o v a l however t h a i n s t a l l a t i o n s h o u l d be passed by the F i r e M a r s h a l l . The d i s t r i b u t o r i n B r i t i s h Columbia i s Ma t t J . Le a k e , Western P o l l u t i o n H u n t e r s , 313 F o u l Bay Road, V i c t o r i a , B.C. Huraus T o i l e t T h i s t o i l e t was r e c e n t l y demonstrated to the Boundary H e a l t h U n i t , and t h e S e n i o r P u b l i c H e a l t h I n s p e c t o r , C e n t r a l Vancouver I s l a n d H e a l t h U n i t and a R e g i o n a l E n v i r o n c e n t a l E n g i n e e r . We w i s h t o o f f e r the f o l l o w i n g comments on the Humus T o i l e t : -1 . T h e i r r e p o r t s u g g e s t s t h a t t h i s t o i l e t n ay have a l i m i t e d p o t e n t i a l use f o r Sumner c o t t a g e s o r s k i l o d g e s . 2. O n l y body wastes v i t h the normal amount o f t o i l e t p a per may be d e p o s i t e d i n the t o i l e t . 3. There may be some danger o f f r e e z i n g o f condensed m o i s t u r e i n t h e v e n t p i p e d u r i n g w i n t e r . T h i s nay n e c e s s i t a t e w r a p p i n g the v e n t p i p e v r i t h a type o f h e a t i n g tape which i s o f t e n used f o r water l i n e s i n m o b i l e homes. .2 139 Ho: A l l Health Unit Directors Froa: A.D.H./?Z?. Greater Vancouver Metropolitan Eoard of Health Capital Eegichal District Public Health Inspectors Environmental xlcgineers Be: Ramus. L i t t l e John. Destroilet. Incinolet arji Harire Toilets A msaber of inquiries have 'ceen directed to this office from Health T7nit3 froa persons desirous of installing the Hunus 'Toilet and I vould refer you to Administrative Circular dated IToves'oer 19, 1974-In order to cl a r i f y the situation in respect to the use of the Euans Toilet, the following advice is offered: 1. Ehe Eusrus toilet ray te considered an alternate rethcd tinder the sewage disposal regulations. 2. It i s reasonable to consider a reduction of 35$ in the si^e of the septic tank and f i e l d where a Eirnus toi l e t i s installed. (See Division of Sewage Regulations) 3. Residential installations ar^ limited to fottr persons per to i l e t ; sis persons for industrial uses. e.g. construction camp. 4. The fan and heating element Hus t he operated ccntimcusly. 5- The addition of selected kitchen scraps, garden s o i l and grass cli-D-oings w i l l stimulate bacterial action within the t o i l e t . 6". Periodic addition of water to the compost and reservoir cay oe required to raintain proper humidity conditions. .2 141 APPENDIX F: SEWAGE SYSTEM COSTS -ASSUMPTIONS AND CALCULATIONS 1. BRIDGEVIEW Damage compensation and property a c q u i s i t i o n . Matt Walker of the Surrey Engineering Department estimates that t o t a l costs f o r both w i l l be about $175 per household. ( i i ) Water. On the average, a f l u s h t o i l e t uses 46% of the t o t a l water used by a household, or about 16 gal/capita/day[32]. Assuming 3.1 persons per household, t o t a l water used per year i s about 18,250 gallons. Surrey buys water from the Greater Vancouver Water D i s t r i c t (GVWD) for about 16c per thousand gallons, which gives a cost of water at $2.92 or about $3.00. ( i i i ) Energy. The following c a l c u l a t i o n s are based on information supplied by Jim Wright of Vacusan Systems Ltd. There are two c o l l e c t o r s t a t i o n s , and each has four 25hp vacuum pumps (including one stand-by) and four 15 hp sewage pumps (again with one f o r stand-by). Da"Uy energy use: vacuum pumps - operate £ n r 50 min/hr during peak flows, and there are two of these per day, of four hours each. Thus, 6 pumps x 8(50) min pump x 25 hp 60 min hr = 1,000 hp-hr Sewage pumps - estimated d a i l y flow i s 240,000 gal - each pump can handle 300 gal/min - with s i x pumps, each must handle 40,000 gal/day and must run 40,000 gal = 2.22 hr 300 g a l x 60 m m min hr 142 thus, 6 pumps x 2.22 hour pump x 15 hp = 200 hp-hr Therefore, t o t a l energy use = 1,200 hp-hr 895 kwh/day According to B.C. Hydro, the appropriate rate structure i s #1220, as of March 1, 1977, which i s : f o r a two-month period, 4.25c/kwh up to 2000 kwh, 3«?/kwh from 2000 to 14,000 kwh, 1.75c/kwh over 14,000 kwh, plus $5.10 s e r v i c e charge. Energy use per two-month period i s (895 x 60) 53,700 kwh Therefore, cost = 2000(.0425) + 12,000(.03) + 39,700(.0175) + 5.10 and annual cost = $6869.10 Note: T h i s c a l c u l a t i o n assumes that average energy use of the pumps i s equal to t o t a l design use, but i n f a c t , only about h a l f of design capacity w i l l be needed i n i t i a l l y . The assumption was made through not knowing how the power demand would increase over time; a c t u a l energy costs w i l l therefore be somewhat lower. (b) Package treatment ( i ) Water -r- same as for Vacuum sewer system ( i i ) Energy - according to NPS, the energy cost of the CA-5E model ( i i i ) Maintenance - each of two pumps must be replaced at l e a s t once - 1144.85 i s 8.5 kwh/day or 510 kwh/two months - according to B.C. Hydro, the appropriate rate schedule i s ,4.6<:/kwh up to 550 kwh, then 2<?/kwh beyond 550, plus minimum service charge of $3.00, f o r a two month period. . E n e r g y cost = 6[ 510(.046) every f i v e years, at a cost of about $120 annual cost = 240 = $48.00 5 143 (c) Composting t o i l e t s ( i ) Energy - energy cost of Clivus i s based on a f i g u r e of 0.25 kwh/ day for a small fan, or 15 kwh/two-month period. - using same rate schedule, annual cost = 6[15(.046)] = $4.14 - energy cost of Humus-Toilet, according to s p e c i f i c a t i o n s , i s 0.5 kwh/day; thus, energy cost/year = $8.28 (d) Normalized comparison From the graph on the following page, the t o t a l cost of i n s t a l l i n g sewers f o r 604 u n i t s i s $1,758,000, or a unit cost of $2910. Adding the cost of property a c q u i s i t i o n and damage compensation of $175 per u n i t , T o t a l i n s t a l l e d cost =1,758,000 + 604(175) = 1,863,700 Unit cost f o r 604 units = $3086 2. PANORAMA RIDGE WEST (a) Gravity sewers The following cost figures f o r components of gr a v i t y sewer systems were obtained from A p l i n and Martin: 8" 0 sanitary sewer l i n e , 7-9 feet deep $20.10/lin f t Since these f i g u r e s are estimates, i t i s advisable to add 10% f o r c o n t i n -gencies. 4" 0 s e r v i c e connection to house 42" 0 manhole base and top 42" 0 manhole shaft $4.50/lin f t $500.00 each $55.70/vert f t $100.00 each $90.00/length inspection chambers pressure t e s t i n g (between manholes) Builder's cost per l o t : inspection chamber 100 4" 0 service connection (assuming average 90 feet) 405 t o i l e t f i x t u r e and plumbing 300 t o t a l $805 144 145 Manholes - assume average depth of shaft i s 6 feet - then cost per manhole i s (500 + 6 x 55.70) = $834 (b) Normalized comparison Let x be the number of l o t s at which sanitary sewers are competitive with composting t o i l e t s Assume o f f - s i t e and on-site developer's costs remain constant and only the bu i l d e r ' s cost changes... (370,500 + 805x) (1.1) 2300 (Clivus-Multrum) x 1215 (Humus-Toilet) 

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