UBC Theses and Dissertations
Groundwater and surface water management and drinking water issues in the Hatzic Valley Magwood, Simone Barbara
In rural areas, water is often supplied by private groundwater wells. Individual well owners have little control over the quality of their drinking water which can be impacted by adjacent land use. The objectives of this project were to determine the quality of drinking water in a rural watershed, investigate the links between groundwater, surface water and land use, and compare the results with the residents' perceptions. Field research was conducted in the Hatzic Valley in the Lower Fraser Valley of British Columbia, a rural watershed with mixed land use. With the help of local volunteers, 75 groundwater samples were collected and analysed in July 2002 and March 2003. Stream water samples were collected at 19 stations semi-monthly between May 2002 and May 2003 to determine linkages between 1) land use and surface water and 2) surface water and groundwater quality. A spatial database was created and the percentage of the four predominant land uses were calculated within several radii of the wells sampled. The perceptions and opinions of local residents were collected using a questionnaire and the results compared with the water quality data. Analysis showed that water quality throughout the valley is good; however, two wells exceeded the health standard for nitrate-N and 10 more wells had nitrate-N levels above 3 mg/L (considered indicative of land use impacts). All the wells with elevated N03-N were shallow (less than 12 m deep). Percent forest cover surrounding the wells was negatively correlated with nitrate level, while percent urbanised land was positively related to nitrate. The cause of high nitrate in the urban areas is thought to be from septic systems. Surface water quality was also high but showed overall degradation from headwaters to the mouth as agriculture increased in the watershed. The majority of residents perceived their water quality to be good or excellent. The residents base their perceptions on tangible indicators rather than chemically determined ones as those who have negative perceptions of their water tended to have high levels of iron and manganese rather than nitrate. The latter is detectable without chemical analysis while the former is not. Very few filter, treat or test their water quality on a regular basis.
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