Adjudication & Wellfield Monitoring Support for an Industrial Client

M&A has provided hydrogeologic services for this now-closed facility since 1988. These services have included monitoring and modeling to assess the relationship between groundwater and surface water, as well as reviewing legal and technical documents related to adjudication and environmental issues.


Located near a perennial-to-intermittent river reach, the water supply for this facility was previously pumped from production wells completed in deep basin-fill sediments that could meet peak demands exceeding 16,000 AF/yr. Today, the wells supply a reduced quantity of water principally for municipal use.


Water Rights

  • Reviewed legal and technical documents prepared by the court and other stakeholder experts to evaluate evolving definitions and approaches for distinguishing surface water and groundwater and quantifying associated impacts
  • Prepared expert reports and provided expert testimony regarding the technical criteria to be used for delineating subsurface water that is legally deemed to be surface water and quantifying the magnitude and timing of surface water impacts from pumping.
  • Developed an analysis of the impact of potential surface water reductions on a senior downstream surface-water rights user as part of a risk evaluation of potential adjudication claims.
  • Supported preparation of updated Statements of Claimant for all wells and water sources on property owned by the client

Wellfield and Monitoring

  • Designed and oversaw installation and testing of two 1,000-foot deep, high-capacity replacement production wells in an artesian aquifer to provide supplies for on-going potable and industrial uses at the plant site and municipal uses by the local town population; work included characterization of yield and water quality conditions with depth during drilling and successful design of wells to avoid treatment for naturally occurring fluoride.
  • Abandoned numerous historical productions wells that were located or constructed in a manner to mitigate potential pumping impacts to the shallow alluvial aquifer connected to the stream.
  • Provided review of various potential future redevelopment plans in relation to potential expanded use of the groundwater resources.
  • Designed and installed a monitoring network composed of numerous wells completed in three vertical zones: the shallow alluvial aquifer, the intermediate confining unit, and the deep basinfill aquifer.
  • Developed and implemented a comprehensive monitoring program to track water level responses to pumping and streamflow and characterize water quality conditions and trends to support operational, water rights, and environmental evaluations.
  • Monitored streamflow and vegetation density via visual inspection, automated cameras, and satellite imagery, focusing on a 6-mile perennial-to-intermittent stream reach adjacent to the wellfield
  • Analyzed geologic, precipitation, streamflow, pumping, water level, and geochemical data to evaluate the relationship between groundwater pumping and surface water flows
  • Interfaced with field biologists and conservation groups to support the evaluation of streamflow and riparian ecosystems
  • Prepared annual monitoring reports to document groundwater conditions and changes over time.

Groundwater Modeling

  • Developed a groundwater flow model to simulate historical and project future drawdown responses to pumping from the deeper basin-fill aquifer on the shallow alluvial aquifer system
  • Evaluated and updated transport projections to improve understanding of the site conceptual model
  • Provided third-party review of groundwater flow and transport modeling conducted by others as part of environmental impact evaluations