Solutions for Progress 

Quarry and Cement Plant Discharge Assessment

RBI is providing technical water quality consulting services for completed and on-going studies required for an investigative order issued by the San Francisco Bay Regional Water Quality Control Board regarding discharges from the Permanente Quarry and Cement Plant to Permanente Creek. RBI assisted with negotiating the terms of the investigative order, which was issued to generate data in preparation of the current NPDES permit regulating discharges from the facility. RBI is executing routine chronic toxicity monitoring and implementing a Ceriodaphnia dubia Toxicity Reduction Evaluation (TRE) on the quarry discharge. Additionally, RBI developed and completed a regional study to investigate the impacts of selenium in the facility’s discharge on beneficial uses of Permanente Creek and Stevens Creek. This effort included bioaccumulation modeling of selenium in the food webs that exist in the affected creeks and the areas of San Francisco Bay to which they are tributary.  Potential impacts from selenium in the facility’s discharge were shown to be limited to ponds in and adjacent to Permanente Creek along the boundary of the facility’s property where activities to restore Permanente Creek and remove selenium containing materials and sediments will be implemented.