Montgomery & Associates - Water Resource Consultants
Montgomery & Associates

Hydrogeologic Analyses & Adjudication Support for an Industrial Client

After a facility shuts down, M&A helps convert an industrial wellfield to a supply source that can meet the demands of future residential or industrial water users.

  • M&A Project DescriptionsClient: International mining company
  • Time frame: 1988–present
  • Location: Confidential

M&A has provided a range of hydrogeologic services for this facility, which is now shut down, for over 25 years. Located near a perennial-to-intermittent river reach, the water supply for this facility was pumped from production wells in deep basin-fill sediments that could meet peak demands exceeding 16,000 AFY.

One major focus our work has been providing support for a stream adjudication process. To assess the impacts of historical and future pumping on surface water resources, we have been conducting long-term monitoring. We also developed a groundwater flow model to quantify the relationship between groundwater and surface water at this site.

Other work for this client has included exploring strategies for developing water supplies for potential future uses and replacing several of the original production wells and with new ones to optimize yield and water quality.

Services

  • Monitored streamflow and vegetation conditions via visual inspection, automated cameras, and analysis of satellite imagery, focusing on a 6-mile reach adjacent to the wellfield characterized by perennial to intermittent flows
  • Analyzed precipitation, streamflow, groundwater withdrawal, water level, and geochemical data to evaluate the relationship between groundwater pumping (historical and future) and surface water flows
  • Interfaced with field biologists and conservation groups to support the evaluation of streamflow and riparian ecosystems
  • Analyzed monitoring and modeling data to characterize the relationship between deep pumping and conditions within the shallow aquifer that is connected to the stream
  • Developed a groundwater flow model to project long-term drawdown in the shallow alluvial and deeper basin-fill aquifers in response to pumping
    Integrated long-term monitoring data and hydrogeologic information into the model
  • Developed an economic analysis comparing the value of groundwater produced from its wellfield to the value of alternative water sources in the region
  • Evaluated wellfield operations and performance, projected potential sustainable yields, and developed recommendations for abandoning, rehabilitating, and replacing various production wells
  • Characterized downhole flow and water quality conditions at production wells
  • Designed and provided oversight for field investigations, which included spinner flowmeter logging, borehole geophysical logging, and discrete-zone sampling
  • Identified well completion intervals that would maximize yield while minimizing arsenic and TDS concentrations
  • Oversaw the drilling, testing, and construction of two new production wells
  • Designed and oversaw the installation of a monitoring well network to assess the hydraulic connection between the shallow alluvial aquifer system and the basin-fill aquifer

Outcome

Work for this project is ongoing.