Central San targets nitrogen and PFAS as pollution prevention yields 1.9m lbs of diverted waste

Central San targets nitrogen and PFAS as pollution prevention yields 1.9m lbs of diverted wasteThe Californian wastewater utility is adapting to new regional pollutant requirements and state-level pharmaceutical programs ahead of an upcoming NPDES permit renewal.

The district collected 1.9 million pounds of hazardous waste in 2025, including mercury and pesticides.

Total inorganic nitrogen has been added to the utility's priority pollutants list to meet regional regulatory requirements.

Staff are preparing for targeted PFAS monitoring in the collection system within the next two years.

The utility's pretreatment program conducted 1,090 inspections at 914 commercial and industrial businesses in 2025.

The Central Contra Costa Sanitary District (Central San) in California is shifting its pollution prevention strategies to address emerging contaminants and regional mandates ahead of an upcoming National Pollutant Discharge Elimination System (NPDES) permit renewal. During a June 4 board meeting, district staff presented the 2025 Annual Pollution Prevention Update, a requirement of the utility's current NPDES permit. The district reported collecting over 1.9 million pounds of hazardous waste in 2025, encompassing mercury, pesticides, and pharmaceuticals. However, the utility's legacy pharmaceutical collection program, which has captured 171,000 pounds of medical waste since its inception in 2000, is winding down. Staff noted that all but one of Central San's collection sites transitioned to the state's med project program in 2025. As legacy programs transition, the district is updating its priority pollutants of concern. Total inorganic nitrogen has been added to the district's priority list to comply with regional requirements. To protect the collection system and treatment plant, the utility's pretreatment program conducted 1,090 inspections across 914 businesses and administered 782 discharge permits in 2025. Under a separate stormwater agreement, inspectors also completed 928 stormwater inspections at 833 businesses. Looking ahead to 2026, Central San is preparing to implement targeted monitoring for per- and polyfluoroalkyl substances (PFAS) within its collection system over the next one to two years. The district has actively supported regional legislative efforts to curb these chemicals, noting the successful passage of California AB 1181, which phased out PFAS in firefighting gear. Conversely, efforts to pass AB 823, a bill aimed at banning microplastics and glitter in personal care products, were vetoed, though staff indicated the district will continue to pursue similar legislation. The utility is also monitoring nonylphenol ethoxylates (NPEs)—detergent compounds typically used in industrial applications that can be detrimental to the environment. Staff confirmed to the board that the single industrial laundry facility operating within Central San's service area does not currently use NPEs. The district expects its priority pollutant list to be re-evaluated when it enters the NPDES permit renewal process in the next year.