City of Pismo Beach, Regional Groundwater Sustainability Project (RGSP)

Pismo Beach, CA

The Regional Groundwater Sustainability Project (RGSP) is a regional recycled water project that will reduce the risk of seawater intrusion and improve sustainability for the region’s water supply. The project will inject advanced- treated recycled water from the City of Pismo Beach and the South San Luis Obispo County Sanitation District (Sanitation District) Wastewater Treatment Plants into the Santa Maria Groundwater Basin, establishing a seawater barrier and improving groundwater supply reliability.

Geoscience is helping the prime consultant to build upon an existing groundwater model developed for the project. The initial model analyzed advance- treated water injection and extraction within the City of Pismo Beach. However, because flows from the County Sanitation District’s wastewater treatment plants will substantially increase the amount of advanced-treated water available for injection from approximately 650 AFY to 2,500 AFY, our team is currently expanding the existing model to evaluate injection and extraction scenarios with the additional flows. Specifically, our team is performing the following:

  • Evaluating existing groundwater characterization studies, groundwater models, and groundwater quality data
  • Constructing and calibrating the expanded groundwater model
  • Evaluating injection and extraction scenarios for City of Pismo Beach and Sanitation District wastewater treatment plant flows
  • Conducting an optional Anti-Degradation Analysis to comply with state regulations
Details at a Glance:
  • Client: Water Systems Consulting (WSC)
  • Date: 2016-Ongoing