Groundwater Basin Analysis, Well Installation, City of Fillmore, CA

Client: City of Fillmore

Location: City of Fillmore, CA

Summary: ENTRIX has conducted a series of technical projects for the City of Fillmore related to groundwater use, water quality and well design. Fillmore is entirely dependent on groundwater supply from a limited number of production wells. Water quality in the underlying, unconfined aquifer is relatively good in the uppermost part of the aquifer, but is of marginal quality in lower portions. To ensure utilization of good water quality groundwater, detailed testing and evaluations of water quality at different depths within existing wells was conducted. Dynamic flow testing and depth-specific water quality sampling was conducted at a series of City wells and operational protocols were developed to allow maximum use of the higher water quality shallow groundwater when possible.

Additionally, during drought conditions, partial aquifer dewatering and substantial static water level declines lead to cascading water conditions in City wells causing entrained air issues. Physical well modifications and operational approaches were developed to minimize these issues.

Because of increased residential and industrial development in areas overlying the city’s unconfined aquifer, a series of analyses were conducted to predict the potential water quality degradation that may be associated with the proposed developments. These analyses were primarily conducted in support of California Environmental Quality Act permitting efforts.

Additional support services have included well rehabilitation and downhole repairs, stormwater water quality and TMDL compliance support, water quality modeling, water level modeling of various pumping and water supply scenarios.