Water Stewardship Information Sources
| ID | 740 |
|---|---|
| Citation | Golder Associates Ltd. 2008. Report on Preliminary Steps in the Development of a groundwater protection plan, Whitevale, BC. Prepared for Regional District of North Okanagan. |
| Organization | RDNO |
| URL | http://www.rdno.ca/docs/080506_whitevale_final_GWPP.pdf |
| Abstract/Description or Keywords | Golder Associates Ltd. (Golder) is pleased to present this report, which outlines the initial stages in the development of a Groundwater Protection Plan (GWPP) for the water supply well of the Whitevale Subdivision, near Lumby, B.C. It is our understanding that the Whitevale GWPP is being developed with the assistance of a gas tax grant distributed to the Regional District of North Okanagan (RDNO). The Regional District of North Okanagan (RDNO) is the purveyor of the Whitevale water system and operates and maintains one community well (referred to as the Whitevale Well) located in the northwest area of the service lot at 715 Franklin Road. The Whitevale well was constructed in April 2006 to replace the existing supply well (Old Well), as the capacity of the Old Well had declined in recent years. The Whitevale Well supplies potable water to approximately 100 residential lots within the Whitevale Subdivision. Given the dependence of the Whitevale water users to groundwater, the implementation of a GWPP is considered critical for the protection of the water source and water quality. The Whitevale GWPP was developed using the Well Head Protection Toolkit used as a guideline, focusing on the initiation of Steps One (Planning), Two (Capture Zone Analysis) and Three (Contaminant Inventory). Based on the results of this initial phase of development of a GWPP for Whitevale, the following conclusions are made: • The Whitevale Well supplies all residential water requirements for approximately 100 residential lots that are connected to the Whitevale water distribution system. • The Whitevale Well draws water from a confined aquifer, identified in the MOE Aquifer Classification System as Aquifer No. 317 and classified as moderately utilized with a low vulnerability to contamination. • The Whitevale Well was constructed in 2006 in accordance to GWPR standards and has a surface annular seal that extends at least 2 m into the confining layer of the aquifer. The lateral extents of Aquifer No. 317 are the mountain slopes to the north and south of Whitevale, Aquifer No. 352 to the west and Aquifers No. 318 and 319 to the east. Although the top of the aquifer is identified a the till/clay confining layer at a depth between 12 m below ground surface (bgs) and 21 m bgs, there are no well logs in the MOE database that are deep enough to identify the bottom of the confined aquifer. An examination of MOE well logs identified three wells between Bessette Creek and the Whitevale Well where a confining layer was not encountered above Aquifer No. 317, indicating the possible presence of an abandoned channel containing sand and gravel in this area. The inferred abandoned channel is likely hydraulically connected to Bessette Creek and likely acts as the recharge area for the Whitevale Well. • An elevation and location survey was completed on four wells and the static water levels measured, which provided a groundwater flow direction in the confined aquifer to the northwest, towards Duteau Creek. The localized hydraulic gradient was calculated to be approximately 0.016 m/m. The groundwater flow direction in the shallow, unconfined aquifer is unknown. • A water balance calculation for the Bessette Creek catchment area to the Whitevale Well provided an annual aquifer recharge estimate of 1.3×107 m3 /year, annual extraction range of 6.9×105 m3 /yr to 8.7×105 m3 /yr and an annual net surplus of 1.2×107 m3 /yr. The utilization rate calculated was approximately 6%. (Note this calculation is for all aquifers in the unconsolidated valley bottom materials. There is insufficient information to complete a water balance solely for the confined aquifer). • The preliminary 60-day time-of-travel zone of the Whitevale Well was estimated using an analytical equation method based on known aquifer parameters and the maximum recommended pumping rate for the Whitevale Well. Longer time-of-travel zones (for example, 1-year time of travel) were not calculated because the 60-day time-of-travel zone intersected a positive recharge boundary. As the 60-day time-oftravel zone is strongly influenced by the groundwater flow direction and hydraulic gradient, a buffer area around the 60-day time-of-travel zone was also estimated to compensate for potential seasonal fluctuations in groundwater conditions. • The southern boundary of the 60-day time-of-travel zone intersected an inferred abandoned channel of Bessette Creek, located at approximately 175 m south of the Whitevale Well. This corresponds to the positive recharge boundary identified approximately 200 m from the Whitevale Well based on the results of the pumping test completed at the time of construction. • A preliminary Groundwater Under the Direct Influence of surface water (GUDI) assessment indicated that the Whitevale Well does not meet criteria that would flag the well as potentially GUDI. • The contaminant inventory indicated residential and agricultural land uses within the 60-day time-of-travel zones of the Whitevale Well. Inactive or old wells, including the Old Well, domestic septic systems and a neighbouring high density feed lot (or over-wintering pasture) are considered very high priority in regards to the risk of contamination to the Whitevale Well. • The inferred abandoned channel of Bessette Creek and suspected inactive wells within the 60-day time-of-travel zone and buffer area are considered to represent a high priority contaminant risk to the Whitevale Well. • Moderate priority contaminant risks to the Whitevale Well were identified as agricultural land used to grow crops, potential spills from accidents on the roads, use of road salt and residential land use. |
| Information Type | report |
| Regional Watershed | Shuswap |
| Sub-watershed if known | Whitevale |
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| Project status | complete |
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