Groundwater Modeling and Reporting Services for the West Coast Basin Barrier Project

West Basin Municipal Water District is seeking qualified firms to perform groundwater modeling services. This work is in support of the ongoing West Coast Basin Barrier Project (WCBBP). The WCBBP uses a hydraulic barrier to prevent seawater intrusion into groundwater aquifers. The project is regulated by the current Barrier permit (R4-2006-0069) issued by the Los Angeles Regional Water Quality Control Board (LARWQCB), the Title 22 Recycled Water Regulations for Groundwater Recharge, and the Recycled Water Policy. Annual groundwater modeling is a requirement of the permit and required topic for the WCBBP Five-Year Engineering Report submitted to regulators.

West Basin Municipal Water District produces advanced-treated recycled water that is blended with potable water and injected into a hydraulic barrier to prevent seawater intrusion in the West Coast Groundwater Basin. The West Coast Basin Barrier Project (WCBBP) is governed by multiple documents, including the following:

• R4-2006-0069; a permit issued by the Los Angeles Regional Water Quality Control Board (LARWQCB)
• Title 22 of the California Code of Regulations (indirect potable reuse groundwater recharge regulations)
• the Recycled Water Policy (amended in 2018 by the State Water Board).

Groundwater modeling is an important part of the WCBBP. The permit requires modeling to be performed annually. An updated technical memorandum discussing the previous year's model results must be included with each annual Barrier report. The five-year engineering report also requires a modeling component and the review of a Professional Geologist (PG), registered in California.