On December 9, 2010, by a 5-0 vote, the California Regional Water Quality Control Board, Central Valley Region ("Board"), issued a new National Pollutant Discharge Elimination System ("NPDES") permit for the Sacramento Regional County Sanitation District ("SRCSD"). In addition to the proposed NPDES permit, a Time Schedule Order was issued to allow SRCSD a 10-year construction period to meet the new permit requirements. The Board is responsible for implementing the federal Clean Water Act (codified at 33 U.S.C. § 1251 et seq.) and issuing NPDES permits. The SRCSD is required to obtain a new wastewater discharge permit every five years under the Clean Water Act.
SRCSD serves a population of 1.3 million people and discharges secondary treated disinfected wastewater to the Sacramento River within the Sacramento-San Joaquin Delta ("Delta"). The treated sewage is discharged into the river approximately 10 miles south of Sacramento, near the Freeport Bridge. The new NPDES permit requires upgrading the facility to full tertiary treatment including nitrogen removal (nitrification/denitrification) and tertiary filtration. SRCSD's initial cost estimate for the requisite facility modifications ranges from $1.2 to $2 billion, although there is some disagreement regarding the potential cost. At the hearing, there was much criticism of the crippling cost that would be borne by residents if the permit issued. Board staff responded that, by law, the financial cost necessary to achieve compliance is not a factor the Board was required to consider.
Focusing on their charge to protect water quality, Board staff cited to the ailing Delta to support the new permit. Board staff emphasized that while the Sacramento-San Joaquin Delta Reform Act of 2009 ("Reform Act") does not have direct jurisdiction over the Regional Board, the Reform Act informs the Board that the Delta ecosystem is in a crisis and the current Delta policies are not sustainable. The Reform Act contains co-equal goals for the State: achieving greater water supply reliability and protecting and enhancing the Delta ecosystem.
State and Federal regulations allow consideration of dilution in establishing effluent limitations. Board Staff considered a mixing zone analysis and rejected dilution credits for ammonia and nitrates due to aquatic toxicity and anti-degradation requirements to meet Best Practicable Treatment or Control standards. Board staff discounted the California State Department of Public Health guidelines requiring only disinfection to secondary treatment levels when dilution exceeds wastewater flows by 20 to 1. The Board staff report for the tentative NPDES permit contained alternative proposals for nitrogen removal and tertiary filtration for Board consideration. Board staff did not recommend any of the treatment alternatives and instead recommended California Title 22 tertiary disinfection standards due to the Delta being a major source of drinking water and the high number of direct recreational contacts downstream of the discharge. The Board agreed with staff's recommendations.
SRCSD questioned the technical evaluations contained in the NPDES permit, as well as the benefits to the environment relating to their estimated $2 billion in capital expenditures. The SRCSD argued that the grounds for the tentative permit were not based on sufficient scientific data that demonstrates the Delta ecosystem is being harmed. The Board's staff responded that the law did not require them to demonstrate the existence of a causal relationship between the effluent and impacts to the Delta ecosystem, but that beneficial uses are being impacted, including contact recreation and drinking water supplies. The Board adopted the NPDES permit with language to clarify that if new studies for ammonia and nitrates reveal new results, the permit could be reopened. The Board's decision will likely impact the 1.3 million people served by the SRCSD facility.