City of Willits Water System Infrastructure
Engineering & Environmental Services
Willits, CA

EBA is assisting the City of Willits with a wide range of groundwater, environmental, and civil engineering services related to the City’s water system infrastructure.  EBA’s scope of work includes groundwater studies, groundwater flow modeling, lead service line inventory (LSLI) compliance services, and civil engineering design and standards development.  Key services provided to date include:

• Lead Service Line Inventory (LSLI) technical support, including compiling historical records, evaluating service line material classifications, creating a Digital Archive Database (ABPDAD) of scanned as-built drawings, and preparing required reporting and public notifications to comply with LCRR and SWRCB-DDW regulations.
• Assistance with preparation and submittal of grant funding applications to the State Water Resources Control Board (SWRCB) to obtain financial support for lead service line inventory efforts.
• Preparation of groundwater flow models to evaluate the hydraulic and storage capacity of City aquifers, using MODFLOW-NWT software. Modeling evaluated recharge, discharge, storage change, well pumping, and groundwater-surface water interactions, with calibration to observed groundwater levels and available streamflow records.
• Completion of arsenic contamination studies, including a Limited Phase I Environmental Site Assessment (ESA) and conceptual groundwater transport modeling to assess potential risk of arsenic migration between aquifers and inform long-term water supply management strategies.
• Preparation of Annual Groundwater Monitoring Reports summarizing groundwater production, groundwater levels, and water quality data in accordance with the City’s Groundwater Operational Use Plan (GWOUP).

EBA’s work has been instrumental in helping the City of Willits strengthen regulatory compliance, improve long-term water resource management, enhance the reliability of critical infrastructure, and plan for future community needs.