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Client:
City of Olympia |
Background
McAllister Springs has supplied most of Olympia’s drinking water
since 1949. However, recent studies by PGG and others have highlighted
the springs’ susceptibility to land use impacts, which could diminish
water quality during periods of heavy demand and drought. To address these
concerns, the City of Olympia decided to replace this supply source with
high-capacity wells.
Challenges
PGG needed to identify an optimum location for a new wellfield—one
where sufficient supplies of groundwater could be obtained and where land
use activities would be unlikely to impact water quality. Furthermore,
we needed to assess the possible environmental effects of operating such
a wellfield, including impacts to nearby water users, surface water bodies,
habitat, and aquatic resources.
Approach
Our work for this project began with a hydrogeologic characterization
of the McAllister Springs area. After identifying an optimal location
for a wellfield, we designed and tested a series of wells to assess potential
yields and water quality. We also helped the City address regulatory issues
related to procuring water rights.
Outcome
PGG installed two high-capacity production wells that now supply up to about
5 MGD (million gallons per day) of water. The comprehensive monitoring
network we developed provides information about long-term trends in water
levels.