Groundwater Projects


Service Overview

Our in-house groundwater resources team offers a full-service approach across the entire spectrum of disciplines including studies and planning; modeling; regulatory and permitting assistance; well rehabilitation and new municipal and ASR well design; funding assistance; construction phase services; and operation, maintenance (O&M), and optimization of existing systems. We bring the value of understanding and knowledge gained from groundwater modeling and aquifer evaluations, through planning and into the design of facilities that best meet your long-term goals of quantity, quality, and conjunctive use supply strategies. In addition, West Yost staff can apply construction and O&M knowledge to the design process to improve construction document quality and reduce construction risks, costs, and delays.

Our groundwater expertise includes the following:

Permitting/ Regulatory Compliance

  • Groundwater Impact Analysis
  • Groundwater Management Plans
  • State Department of Public Health Services and Regional Water Quality Control Board Coordination Planning
  • Field Investigations
  • Groundwater Modeling
  • Groundwater Investigations and Basin Management Planning
  • Drought Response/Preparation
  • Aquifer Testing
  • Groundwater Monitoring Plans
  • Feasibility Studies for Conjunctive Use, ASR, Groundwater Banking and Recycled Water
  • Aquifer Storage and Recovery Programs
  • Well Condition Assessments

Design (See Also Infrastructure Design)

  • Groundwater Wells (Monitoring and Production) and Pump Stations
  • Well Redevelopment and Rehabilitation
  • Injection/Extraction, Aquifer Storage and Recovery Wells/Facilities
  • Dewatering Systems and Facilities
  • Groundwater Banking Facilities and Recharge Basins
  • Groundwater Treatment Systems
  • Well Development Bidding Assistance and Construction Oversight


  • Groundwater Facility Optimization and O&M Support

Groundwater Projects


Grogan Park Production Well
City of Modesto, California

West Yost is providing hydrogeologic and engineering for the City’s Grogan Park (formerly known as the Tivoli Well) Production Well. The goal of this project is to construct a new municipal well with the capacity of approximately 1,000 gpm or more without the need for wellhead treatment.


Sunset Well Rehabilitation
South Tahoe Public Utility District, California

West Yost evaluated, rehabilitated, and tested the Sunset Well to reestablish well efficiency and normal flow conditions. This project included conducting a condition assessment of the well and down-hole equipment, measuring the well performance before and after rehabilitation including an assessment of the maximum sustainable yield, and sampling for Title 22 drinking water constituents.


Groundwater Master Plan, and Well Siting, Design and Construction Management
City of Santa Rosa, California

For the last 13 years, West Yost team members have served as the City’s water resources consultant, working closely with City staff to provide technical support on water supply and groundwater projects/programs. This support has ranged from groundwater basin management planning and technical studies, through groundwater modeling, well siting, wellfield management, well rehabilitation, wellhead treatment, development of groundwater GIS support tools and Aquifer Storage and Recovery.


Hydrogeologic Characterization and Modeling Study for South East Bay Plain Basin Groundwater Management Plan Development Project
East Bay Municipal Utility District, California

The South East Bay Plain (SEBP) basin study was conducted to support development of EBMUD’s Groundwater Management Plan (GMP) as part of EBMUD’s efforts to implement conjunctive use to improve water supply reliability. The project study area includes the City of Hayward.











The project included the following activities:


Aquifer Storage and Recovery Wells
City of Roseville, California

The objective of Roseville’s Aquifer Storage and Recovery (ASR) Program is to store surplus drinking water (10,000 acre-feet per year) in the underlying aquifer during periods of normal and above normal precipitation. This stored drinking water is then extracted and served to meet peak demands. West Yost provided design and construction management services for two ASR wells for the City.


New Municipal Well and Well Rehabilitation
City of Modesto, California

West Yost provided design and construction of new municipal wells and evaluation and potential rehabilitation of three wells known to have impaired water quality. Each of the six municipal well capital improvement projects was constrained by the minimum well yield needed to meet system supply and pressure requirements, California Division of Drinking Water (DDW) water quality requirements for public drinking water supply sources, and cost.


On-Call Hydrogeologic Consulting Services
City of Modesto, California

West Yost’s team has provided a variety of on-call hydrogeologic consulting services supporting the City of Modesto. The City owns over 100 water wells, some of which are in need of rehabilitation or replacement due to age, poor water quality, or both. West Yost has helped with City to evaluate hydrologic and geophysical test boring data to recommend the next City production well site and will then support drilling operation and design for a new production well.


ASR Program Development and Modeling, Davis-Woodland Water Supply Project
Woodland-Davis Clean Water Agency, California

The Woodland-Davis Clean Water Agency is a Joint Powers Authority representing the water supply interests of the cities of Davis and Woodland. Under the Aquifer Storage and Recover (ASR) Program, the City of Woodland is implementing a comprehensive ASR Program to help address its water supply needs during periods of peak demand and/or drought. The City of Davis may also choose to undertake its own ASR Program.


Aquifer Storage & Recovery (ASR) Well 28
City of Woodland, California

The Woodland Davis Clean Water Agency (Agency) and the City, in conjunction with West Yost, conducted an evaluation of ASR as a component of the overall water supply for the Davis Woodland Water Supply Project (DWWSP), designed the first ASR facility for the City, completed construction of the project, and have recently begun injection testing for the ASR well.


Well Blending Study
City of Ceres, California

West Yost conducted an initial hydraulic analysis of the potential to blend the elevated uranium concentrations in one well with water from other wells to produce an acceptable blended uranium concentration (less than or equal to 80 percent of 30 mg/L MCL). Utilizing the City’s water system hydraulic model, West Yost estimated the extent of possible dilution and coordinated with City staff to develop a proposed well operation plan and valving arrangement to force water from other wells to the Smyrna Well vicinity.


Big Horn Municipal Wells
Sacramento County Water Agency, California

West Yost provided design services for a new 6,000 gpm groundwater supply in Sacramento County. Typical production depths in the area yield groundwater with arsenic concentrations that can approach or exceed the 10-µg/l federal Maximum Contaminant Level (MCL). Deeper zones can contain concentrations of manganese, iron and other constituents that exceed secondary MCLs and can require treatment. Groundwater from the wells meets all drinking standards. The wells were designed and constructed to enable sealing of zones that may be affected by water quality changes in the future.


Southern Yolo County Deep Aquifer Study
University of California, Davis, and the cities of Davis and Woodland, California

West Yost evaluated the capacity of the deep aquifer zone (approximately 700 to 1,500 feet below land surface) for future water supply development by the cities of Davis and Woodland and UC Davis. As part of this study, West Yost performed aquifer tests using City and University production wells. The largest test involved pumping at an average rate of approximately 2,500 gpm for 13 days.


Municipal Well Design and Hydrogeologic Consulting Services
City of Woodland, California

West Yost is supporting the City of Woodland’s (City) efforts to expand and improve the quality and sustainability of its groundwater supply. The City relies completely on groundwater, which is produced from an intermediate depth aquifer. The City is expanding its groundwater production to meet projected water demands and improve water quality by constructing new wells in a deeper aquifer zone which, locally, has superior water quality. West Yost has evaluated hydrogeologic conditions and groundwater quality, designed the wells, and provided hydrogeologic support during construction. West Yost is currently preparing a groundwater management plan for the City.


Stony Creek Fan Aquifer Performance Testing
Stony Creek Fan Partners, California

West Yost is currently providing hydrogeologic consulting services for investigation and aquifer performance testing of the Lower Tuscan Aquifer as part of the Stony Creek Fan Conjunctive Water Management Program, a multi-year research program in Glenn County. The study will help characterize the extent, hydraulic properties, water quality and sources of recharge in the Lower Tuscan Formation and related parts of the aquifer system.


Nevada/Utah Regional Groundwater Model and Impact Analysis
U.S. Department of Interior

West Yost is developing a groundwater model for eastern Nevada and western Utah. The work is being conducted jointly for the U.S. Fish and Wildlife Service, U.S. Bureau of Land Management, National Park Service, and U.S. Bureau of Indian Affairs. The model covers an area of about 25,000 square miles. The model will be used by theses agencies to assess the impacts of proposed groundwater exports from the model area. 


Aquifer Storage and Recovery (ASR) Demonstration Project
City of Tracy, California

West Yost is responsible for managing and directing technical work associated with the feasibility of implementing an aquifer storage and recovery (ASR) program for the City. This program involves the injection of treated surface water (when available during the winter months) into the groundwater basin for storage and later extraction during peak demand periods or dry years.