For all wastewater treatment plants, the level of treatment required before the water can be released back into the environment is dictated by a National Pollutant Discharge Elimination System (NPDES) permit. For Regional San, this wastewater discharge permit is issued by the Central Valley Regional Water Quality Control Board (Regional Water Board), the state agency that regulates wastewater dischargers in our region.
Regional San’s 2010 discharge permit contains strict mandates that require us to construct costly new “tertiary” treatment processes for ammonia and nitrate removal, filtration and enhanced disinfection:
Ammonia and nitrate removal: Using a process called “biological nutrient removal” (BNR), this will eliminate nearly all ammonia and most nitrate from the effluent (treated water), addressing concerns about possible impacts these constituents may have on the ecosystem, both here and downstream.
The requirements of our new discharge permit will cost our region’s ratepayers about $1.5-2.1 billion to build. On top of that, about $50 million per year in ongoing maintenance and operations costs are anticipated.
Gradual annual rate increases to fund these improvements have already been implemented. No further rate increases will be necessary for the remainder of the project, which must be completed in 2021–2023. For more information on the rate impacts of the EchoWater Project, please visit Monthly Rates.