British Columbia Mine Reclamation Symposium

Reclamation of mine openings at the historic Highland Mine and Kootenay-Florence Mines, Ainsworth, British.. Mchaina, David Mhina; Weirmeir, Michael 1999-06-25

You don't seem to have a PDF reader installed, try download the pdf

Item Metadata

Download

Media
59367-1999 - Mchaina, Weirmeir - Reclamation of Mine Tailings.pdf [ 1.36MB ]
Metadata
JSON: 59367-1.0042340.json
JSON-LD: 59367-1.0042340-ld.json
RDF/XML (Pretty): 59367-1.0042340-rdf.xml
RDF/JSON: 59367-1.0042340-rdf.json
Turtle: 59367-1.0042340-turtle.txt
N-Triples: 59367-1.0042340-rdf-ntriples.txt
Original Record: 59367-1.0042340-source.json
Full Text
59367-1.0042340-fulltext.txt
Citation
59367-1.0042340.ris

Full Text

Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation RECLAMATION OF MINE OPENINGS AT THE HISTORIC HIGHLAND MINE AND KOOTENAY-FLORENCE MINES AINSWORTH, BRITISH COLUMBIA Dr. David Mchaina - and - Michael Weirmeir Boliden Limited Suite 1500, West Tower 3300 Bhor Street West Etobicoke, Ontario  M8X 2X2 ABSTRACT This paper discusses mine closure aspects of an abandoned mine workings located in southeast British Columbia. The Highland Mine and adjacent mines were discovered in the 1890's and produced at various intervals until the late 1950's. During the summer of 1997, one of the old Highland Mine portals collapsed and released an unknown quantity of iron-rich water into Cedar Creek. This event led to a review of all the surface openings of the Company's Ainsworth lands in terms of meeting the BC Health, Safety and Reclamation Code requirements. The closure aspects considered included preliminary assessment, site investigations, decommissioning and reclamation work planning, design implementation, cost estimates, alternative evaluation, contractor selection and implementation. The paper will also address environmental, stakeholder consultation aspects and follow-up. INTRODUCTION The former Highland and Kootenay-Florence mine sites are located on a group of 41 Crown grants held by Boliden Westmin (Canada) Limited, near the unincorporated Village of Ainsworth, in southeastern British Columbia. Perched on a hillside overlooking Kootenay Lake, Boliden's lands also comprise the Lakeshore Mine (formerly, Twin Mine) and a number of other small production and exploration workings. The Highland Mine and Kootenay-Florence (K-Florence) were the most significant in terms of production and number of workings. With original discoveries made in the 1890's, the area saw production until the late 1950's. The Highland Mine was purchased in 1912 by Cominco Ltd. who operated it fairly continuously until 1926. Lessees operated the mine between 1947 and 1954. Western Mines Limited* acquired the property in 1957. The Kootenay-Florence Mine began operations in 1916 under the Florence Silver Mining Company. Since then, the property has changed ownership several times and experienced various levels of production. 1926: Kootenay Florence Mines Limited 1942: Wartime Metals Corporation 1945: Ainsmore Consolidated Mines 1946: The Spokane Group 1951: Cominco Ltd. - 224 - Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation 1957:     Western Mines Limited * Western Mines Limited became Westmin Resources Limited. Westmin assets were acquired by Boliden Westmin Canada Limited in 1998. No production has been undertaken on the lands since 1957. Figure IA shows the location of the Highland Mine area in relation to other properties in the Ainsworth area. -225- Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation  -226- Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation GEOLOGY AND OPERATIONAL HISTORY Geology Three vein-filled faults occur over a 61.Om wide zone in the Josephine Formation, 365.8m strarigraphically above the lower limestone member. The best grade ore occurs in hornblende schist where juxtaposed with quartzite or limestone in the footwall. Fissures trend 130 to 145 degrees and dip 75 degrees southwest with 6.1m to 39.6m of left lateral displacement. Most of the ore was mined from the most southerly fissure. The greater the displacement along the fissure, the greater the width of the vein (Manning, 1958). Intersection of the faults with the southwest-dipping hornblende schist and quartzite results in west-raking ore bodies. Minor replacement mineralization occurs adjacent to the fissure veins where they cut thin limestone bands. The south fault at Highland Mine extends west to the Guichon Mine in the Buckeye limestone and to the east to Jewel deposit on Yale Lead-Zinc Co. property. SITE DESCRIPTION Highland Mine The Highland Mine ore zones were accessed by seven production portals and exploration occurred at three short adits. The mine site is located 5.6 kilometres from Kootenay Lake, first following Cody Caves Road for +/- 3.6 kilometres and Highland Mine Road (a.k.a. Spur 300 to the Forestry operator) for two kilometres. This report deals with three of the production portails as follows: No. 2 Level Portal The portal entrance had extensive timbering and a steel meshgate at its entrance. The portal dimensions are 2.13m X 2.13m. The portal was dry and did not depict any signs of historic water discharge. The portal is securely gated and complies with standards for a temporary closure as per Health and Safety and Reclamation Code Section 6.4.1 (HS&R), hence was not of immediate concern; however, the Company favoured a permanent closure of the portal. A waste rock dump is situated adjacent to the portal and depicts a slope angle of approximately 37 degrees. Based on visual inspection and age of the dump, Boliden Westmin (Canada) Limited and government agents agree that the dump is stable and does not require any stabilization work. No. 3 Level Portal The portal is located below No. 2 Portal and above No. 7 Portal. The portal entrance had extensive timbering and a steel mesh gate at its entrance. The portal dimensions are 2.44m x 2.44m. The portal is dry and does not depict any signs of historic water discharge. The portal is securely gated and complies with standards for a temporary closure as per HS&R Section 6.4.1, hence was not of immediate concern; however, the Ministry favoured a permanent closure of the portal. -227- Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation A waste rock dump is situated adjacent to the portal and depicts a slope angle of approximately 37 degrees. Based on visual inspection and age of the dump, Boliden Westmin Limited and government agents agree that the dump is stable and does not require any rehabilitation work. No. 7 Level Portal The portal is located approximately 50 metres from Cedar Creek. The portal was accessed through rough and steep terrain environments. Biased on visual observations, the portal collapsed and became blocked. The portal is connected to workings topographically higher in the mountain. The portal collapsed presumably in the spring of 1997 as a result of water built up behind the blockage until it forced a hole through the blockage and drained the mine workings. Evidence at the site suggests that this was a large event with peak flows approaching a significant percentage of Cedar Creek flow. Based on a joint inspection by Boliden Westmin Limited and government agents conducted on July 23, 1997, a constant flow of approximately 100 - 200 litres per minute was recorded. The water discharged out of the portal has a slightly milky orange discoloration and is leaving an orange precipitate on the surface. Water samples were taken for dissolved and heavy metals analysis. The outflow event also resulted in the erosion of between 1,500 and 3,000 cubic metres of till material between the portal and the creek. The till material was transported and deposited into Cedar Creek. The site depicts signs for further potential slope failures as the portal is presently blocked. KOOTENAY-FLORENCE MINE The Kootenay-Florence Mine ore zones were accessed by five production portals. Exploration occurred at a number of short adits. The mine site is accessed at points along the first kilometre of Cody Caves Road and within one kilometre of where Harriet Metals Road ("Spur 100" to forestry interests) branches south. The access tunnels are quite extensive with Level 9 tunneling reaching 2,400 metres by 1929 (cease of operations). The workings range in elevation of 590 metres at Level 9 to 850 metres at No. 1 Level. No 5 Level Portal The portal is located off the Cody Caves Road. The current portal entrance had extensive timbering and a steel mesh gate at its entrance. The portal dimensions are 2.13m X 2.13m. The portal was wet and depicted signs of continuous water discharge. The portal is securely gated and complies with standards for a temporary closure as per Health and Safety and Reclamation Code Section 6.4.1 (HS&R); as a result, the portal safety status does not present an immediate concern. However, the Ministry of Energy and Mines favoured a permanent closure of the portal. Kootenay-Florence Sinkhole A sinkhole located east and adjacent to the "Harriet Metals" road ("Spur 100" to forestry operators) on the Laura M claim was observed during inspection and presented a safety hazard. It was fenced with a "Caution " tape and has been closed out to prevent inadvertent access. -228- Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation The subsidence may be associated with the underground workings of the Kootenay-Florence No. 5 Level.  No. 9 Level Portal No. 9 tunnel is located approximately 100 metres off the Cody Caves Road and above No. 31 Highway. The tunnel is connected to workings topographically higher in the mountain. The portal measured 2.44m X 2.44m. The portal entrance had extensive timbering at its entrance. The portal was wet and discharges approximately 100 litres per minute into Princess Creek. The water discharged out of the portal bas a slightly milky orange discoloration and is leaving an orange precipitate on the surface. The portal is securely closed and complies with standards for a temporary closure as per HS&R Section 6.4.1. The main concern associated with the portal / tunnel is drainage. The portal was decommissioned to meet permanent closure requirements. DECOMMISSIONING AND CLOSURE OPTION FOR HIGHLAND MINE PORTALS AND ADJACENT PROPERTIES The following alternatives were considered and the Company selected alternative No. 3 and proceeded with rehabilitation and reclamation work. Reclamation Alternatives * Alternative No. 1: No Action * Alternative No. 2: Institutional Controls * Alternative No. 3: Decommission & Reclaim Site Comparative Analysis of Alternatives  Objectives of Decommissioning Plan The main objectives of the decommissioning and rehabilitation plan are: * continued protection of public health and safety * prevention or elimination of negative environmental impact * control and minimize future maintenance and active care requirements The long-term objective is to rehabilitate the Highland Mine portals to meet the Health, Safety and Reclamation Code (HS&R) requirements. -229- Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation Closure and Rehabilitation Objectives and Potential Measures for Openings to Surface The closure and rehabilitation objectives and potential measures for openings to surface related to the Highland Mine and adjacent properties are given in Table 1. The selection of preferred measures was based on a number of considerations including: * practicability * longevity * security / risk * environmental impact * construction methodology * inspection and maintenance * effectiveness * cost / benefit TABLE 1  CLOSURE AND REHABILITATION OBJECTIVES  - 230-Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation DECOMMISSIONING APPROACH FOR PORTALS * Three sections (6 m. long) of 304.8 mm diameter HDPE pipe placed on a bed of rock. * Pipes on a slight (0.5%) down grade toward portal entrance. * Pipe sections were perforated. * Coffer dams were constructed to contain suspended solids where applicable. * Controlled blasting approach was employed for ultimate portal closure. Decommissioning and Closure for Highland Mine No. 2 Level Portal The decommissioning plan involved removing mine timbers in front of the portal and laying a bed of coarse rock across the width of the drift and approximately 4 metres. Three sections of 304.8mm diameter PDDPE pipe were placed on the bed of rock. Each section measures 6 metres long and will be on a slight (0.5%) down grade toward the portal entrance. The pipe has perforations in it. With the pipe in place, rock fill was laid on top of it until the rock fill reaches the back of the drift. Figure 1 details the closure plan for No. 1 Portal. Decommissioning and Closure for Highland Mine No. 3 Level Portal The decommissioning plan involved provision of drainage and closure of the portal by controlled blasting. Three sections of 304.8mm diameter HDPE pipe were placed on the bed of rock. Each section measures 6 metres long and was placed on a slight (0.5%) down grade toward the portal entrance. The pipe has perforations in it. With the pipe in place, controlled blasting approach was employed to close the portal. Figure 2 details the closure plan for No. 2 Portal. Decommissioning and Closure for Highland Mine No. 7 Level Portal Closure and decommissioning work was scheduled during the fish window. The decommissioning plan involved removing big stump, tree and associated blockage, provision of drainage and laying a bed of coarse rock across the width of the drift and approximately 4 metres long into the portal entrance. Three sections of 304.8mm diameter HDPE pipe were placed on the bed of rock. Each section measures 6 metres long and is on a slight (0.5%) down grade toward the portal entrance. The pipe has perforations in it. With the pipe in place, rock fill was laid on top of it until the rock fill reaches the back of the portal. A coffer dam to retain sediments during the closure program has been constructed. The eroded area downstream of the portal was resloped to minimize further erosion. In addition to the above, the following preparation work was undertaken: * a trail through the logged area was established; * drain rock has been hauled to this site and a foot bridge across Cedar Creek was installed; Figure 3 details the closure plan for No. 3 Portal. •231 • Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation  Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation  this page intentionally left blankProceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation  Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation Decommissioning and Closure for Kootenav-Florence Mine No. 5 Level Portal The original portal entrance had extensive timbering and a steel mesh gate at its entrance. The portal dimensions being 2.13m X 2.13m. The portal was wet and depicted signs of continuous water discharge. The portal was securely gated and complied with standards for a temporary closure as per Health and Safety and Reclamation Code Section 6.4.1 (HS&R); as a result, the portal safety status does not present an immediate concern. However, the Company favoured a permanent closure of the portal. The portal was sealed and drainage provided as per the decommissioning plan. Kootenav-Florence Sinkhole The sinkhole was back-filled and compacted. Decommissioning and Closure for Kootenav-Florence Mine No. 9 Portal The original portal entrance had extensive timbering and a steel rnesh gate at its entrance. The portal was wet and depicted signs of continuous water discharge. The portal was securely gated and complied with standards for a temporary closure as per Health and Safety and Reclamation Code Section 6.4.1 (HS&R); as a result, the portal safety status did not present an immediate concern. However, the Company favoured a permanent closure of the portal. The portal sludge and mud were drained and a settling pond was constructed to restrict solids from entering Kootenay Lake. The closure work included the following activities: * all iron-rich mineral slimes, mud and wood were removed up to portal entrance; * road access was established with minimal disturbance; * sandbag coffer dam was built; * water flow was diverted through temporary lines; * adit gate and headings were removed; * the mucked-out slimes were deposited in a nearby suitable location and was marked on a map complete with GPS coordinates of the disposal site; * the portal was closed with rock/earth fill and drain pipes in the same manner used for the other portals. ROAD DECOMMISSIONING AND CLOSURE; Boulder Fence Road access to the portail entrances was restricted tlirough the use of boulders (minimum 1.25 metre diameter) spaced a maximum of 0.6 metres apart. These boulder barricades are located at the access points to the working of the Cody Caves and Highland Mine Roads (Spur 300). -235- Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation MONITORING PROGRAM - POST CLOSURE: Water Quality During the inspection and closure of the sites, the Company initiated a water quality sampling program as detailed in Table 2. TABLE 2  WATER QUALITY SAMPLING PROGRAM  - 236 -Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation Water Monitoring Program The Company proposed a water monitoring program for key parameters following close-out implementation to assess the success of the close-out remediation measures and to identify any upsets that may require corrective action. The monitoring program and parameters analyzed will be reviewed annually for two years. An annual report will be prepared to summarize data. A two-year demonstration period is proposed. At the end of this period the Company will prepare a report summarizing all monitoring data and assess the overall performance of the closure plan. As the results of the close-out activities show improvement with time, the Company will pursue elimination of the monitoring requirements and consider the portals closed out permanently. SAFETY ISSUES  Warning Signs For Entry At the completion of the Highland Mine decommissioning program, signs will be posted at conspicuous locations advising the public of (a) road closure and (b) authorized access only. PRE- AND POST-CLOSURE CONSULTATIONS In order to foster better communication and to comply with various regulatory requirements, the Company will initiate pre- and post-closure meetings with stakeholders such as the Ministry of Energy and Mines and Ministry of Environment. The objective is to review all regulatory requirements related to pre- and post-closure of the facilities covered in this report. Boliden Westmin Limited proposes that the Ministry of Energy and Mines, Energy and Minerals Division to be the lead agency and all closure issues to be directed through the agency. -237- Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation SUMMARY OF PROJECTS STATUS -238- Proceedings of the 23rd Annual British Columbia Mine Reclamation Symposium  in Kamloops, BC, 1999. The Technical and Research Committee on Reclamation REFERENCES Bourne, D.A., 1953, Geology and Ore Reserves of Western Mines Limited, Ainsworth, B.C.; private company report May 27, 1953. Eastwood, G.E.P. (1952), Highlander-Hot Springs Area. Minister of Mines Province of British Columbia, Annual Report 1951, pp. 144-155. Hedley, MS. (1952), Kootenay Florence (Western Mines Limited) Minister of Mines Province of British Columbia, Annual Report 1951, pp. 156-159. Hill, H.L., 1953, Preliminary Report on Ainsmore Consolidated Mines Limited, Ainsworth, B.C.; private company report July 26, 1951. McDougall, B.W.W. (1931), The Kootenay Florence Mine, Ainsworth Mining Division, West Kootenay District, British Columbia (private report). Manning, S.M., 1958, Report on Western Mines Limited, Ainsworth, B.C.; private company report September 30, 1958. Powelson, J.M., 1957, Summary Report on the Western Mines Property, Ainsworth Mining Division, British Columbia; private company report, November 30, 1957. Rice, H.M.A., 1944, Notes on Geology and M:ineral Deposits at Ainsworth, British Columbia; Geol. Survey of Canada, Paper 44-13. Richardson, J. (1953), Kootenay Florence Mine, Geological Report. The Consolidated Mining and Smelting Company of Canada Limited, Geological Division, Mine Series Section - Geological Report No. 1; private company report March 10, 1953. Robinson, J.W., 1954, Report on the Western Mines Limited, Ainsworth, B.C.; private company report January 14, 1954. Schofield, S.J., 1920, Geology and Ore Deposits of Ainsworth Camp, B.C., Geol. Survey of Canada, Memoir 117, 73 p. and maps. Fyles, J.T., 1967, Geology of the Ainsworth-Kaslo Area, British Columbia, Dept. of Mines Bulletin No. 53. -239- 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.59367.1-0042340/manifest

Comment

Related Items