Mitigated Negative Declaration Summer Surface Water Discharge Project

RBI prepared the CEQA Initial Study/Mitigated Negative Declaration (IS/MND) for the Summer Surface Water Discharge Project for the City of Galt’s Wastewater Treatment Plant (WWTP). The IS/MND addressed new year-round effluent discharge to Laguna Creek, which was previously prohibited pending WWTP treatment process upgrades. The City had completed Phase 1 treatment process upgrades for 2009 in which RBI assisted with prior CEQA documentation, construction environmental permits, and the renewal of the NPDES permit. With the summer surface discharge project, there were potential concerns regarding effects on state and federal Endangered Species Act (ESA) listed fishers (i.e., Central Valley steelhead, fall-run Chinook salmon, and delta smelt) utilizing the lower Cosumnes River and Delta. RBI prepared a hydraulic analysis (HEC-RAS) of potential changes to Laguna Creek and Cosumnes River instream flow variables that would occur with the year-round discharge to Laguna Creek a tributary to the Cosumnes River. RBI biologists evaluated streamflow depth, velocity, and temperature in the IS/MND to address the primary concern of potential false attraction of fall-run Chinook salmon from the Cosumnes River into Laguna Creek in the fall.