West Yost has supported the City of Woodland’s (City) Aquifer Storage and Recovery (ASR) Program since 2010, conducting services directly for the City and for the WDCWA. Under the ASR program, the City is implementing a comprehensive ASR program to help address its water supply needs during periods of water right curtailments, peak demand conditions, and/or drought periods.
During the initial phases of the work, West Yost conducted feasibility assessments of alternative water supply sources to supplement a planned surface water supply from the Sacramento River. ASR was identified as the most feasible, least-cost alternative and a Work Plan for ASR Program development was prepared.
Implementation included the following:
Monitoring Network Construction and Baseline Monitoring
The West Yost team designed and acted as the City’s representative during the construction of the City’s ASR monitoring network. The team conducted baseline groundwater level and quality monitoring in network wells as part of the ASR program.
Quantification of Water Budget/Numerical Modeling
The West Yost team used the California DWR Modeling Support Branch’s Integrated Water Flow Model (IWFM) to develop a three-dimensional groundwater flow model for Yolo County. The model results supported ASR design efforts and preparation and adoption of the required CEQA Supplemental Environmental Impact Report (SEIR).
Geochemical Modeling
The West Yost team conducted geochemical modeling to establish the potential for plugging of the ASR wells or aquifer, and the potential for mobilization of naturally occurring constituents in the aquifer matrix, including hexavalent chromium.
ASR Injection Testing Using Isotopes and Noble Gases
The West Yost team conducted a stable isotope study to assess the age, movement, and mixing of recharged and native water in the aquifer.
Data Analysis, Interpretation, and Reporting
The West Yost team prepared a comprehensive report on the ASR program studies that was used to support the ASR program in the SEIR, and modification of the surface water right to allow the long-term storage needed for ASR operations.
State Water Resources Control Board Permitting for ASR
The West Yost team acted as the City of Woodland’s representative and prepared on the City’s behalf a Notice of Intent (NOI) to conduct short-term injection testing and a NOI to conduct pilot testing and operations under the State Board ASR General Order. Working with a water right attorney, the West Yost team prepared the technical content for the Underground Storage Supplement application, which was filed with State Board to modify the appropriative water right to allow the long-term storage needed for ASR operations.
ASR Well Design
The West Yost team designed and provided services during the construction of the City’s first ASR well, which won the 2013 ASCE Sacramento Section Sustainable Engineering Project of the Year Award and also won an APWA, Sacramento Chapter, Project of the Year Award. To achieve maximum flexibility, the well was designed and constructed to be used as a standard municipal supply well while also being ASR capable. The West Yost team provided hydrogeologic services during the design, construction and testing of the City’s next two ASR wells.
Key Challenges
- Subsurface information was very limited during the initial stages of ASR feasibility assessment.
- Groundwater modeling challenges included developing 3-D representations of the subsurface geology and assigning pumping rates to private wells in agricultural and rural residential areas where pumping records are very limited or nonexistent.
(Banner image: West Yost identified the ASR production zone and constructed a numerical model of the aquifer system.)
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Team Spotlight
Ken Loy, PG, CEG, CHG
Principal Hydrogeologist II
Ken Loy, PG, CEG, CHG
Principal Hydrogeologist II
“As a specialist in groundwater-related issues, I greatly enjoy being a part of the strong multidisciplinary teams needed to address wide-ranging client needs. Each client is unique, and each project has its own set of challenges. I enjoy learning about the client’s perspectives on these challenges and coming up with the right approach and team to address them. At West Yost we have the internal resources and team atmosphere that really makes the difference, not just within our groundwater and hydrogeology team, but across the board for water-related services. When it suits our client’s needs, we don’t hesitate to extend that collaborative team-based approach to our teaming partners. It’s great to be a part of these win-win situations!
I am especially proud to be a part of the multidisciplinary teams working to meet a variety of needs for our clients. My clients include agencies such as the Glenn and Colusa GSAs and the Santa Clarita Valley Water Authority as well as municipal clients, such as Sacramento Suburban Water District and the Cities of Davis, Dixon, Vacaville, Milpitas, Modesto, Pasadena, Petaluma, Santa Rosa, and Woodland. We have a long history of providing a variety of planning, modeling, design, and construction management services across multiple disciplines, including water and wastewater services, and it’s very gratifying to know that what I do related to groundwater is part of a bigger picture for our clients, our communities, and the sustainability of our environment.”
Anna Reimer, PG
Associate Geologist I
Anna Reimer, PG
Associate Geologist I
“I really enjoy working in the subsurface, looking at what is beneath our feet, the water there, where it is coming from, and where it is going. It is really exciting when we get projects that combine different task types. For example, projects that include or lead to a conceptual study or basin assessment, well construction and testing, groundwater modelling, management planning, and implementation. It is great being able to provide our clients insight regarding how everything is connected and assisting them with identifying beneficial future projects. I enjoy working as a consultant because we get a wide variety of task types that cross different industry sectors.
Recently, I have been working a lot on the development of the Colusa Subbasin GSP, partnering with other consulting firms. This is my first major project for which I am the primary writer of our content. The process has been challenging, but I’m pretty proud of what we have accomplished.”