Supervisors receive TMDL reduction plan for San Luis Rey River

The San Diego County Board of Supervisors voted 5-0 Sept. 26 to receive the total maximum daily load (TMDL) reduction plans for the San Luis River Watershed and two other watersheds.

The acceptance of the report allowed the county’s Department of Public Works to submit the comprehensive load reduction plans for the San Luis Rey River, Chollas Creek, and San Diego River watersheds to the San Diego Regional Water Quality Control Board (RWQCB) by the Oct. 4 deadline.

Federal and state laws require local governments which operate municipal separate stormwater systems to control pollutants. The RWQCB’s bacteria TMDL regulations went into effect in April 2011. The bacteria TMDL resolution requires impacts to be reversed to pristine pre-development levels by 2021 during dry weather conditions and by 2031 for wet weather conditions. The state did not provide local governments with any funding to comply with the limits.

The State Water Quality Control Board regions are based on hydrologic regions rather than county lines, so Region 9 includes part of southern Riverside County and southern Orange County while part of San Diego County is in Region 7. Eight watersheds are affected by the TMDL resolution including the Scripps Hydrologic Area and Tecolote Creek which do not include county land area.

The county shares responsibility with other jurisdictions for the San Luis Rey River, Chollas Creek, San Diego River, San Marcos Creek, San Dieguito River, and Los Penasquitos Creek watersheds. Due to a technicality the county was not required to prepare and submit plans for the San Marcos Creek, San Dieguito River, and Los Penasquitos Creek watersheds.

The TMDL regulations provide for an opportunity to revise numeric standards after five years. The county and other affected agencies are performing a multi-year scientific study to assess and document the merit of the numeric limits to provide a basis for more reasonable goals based on

sound science.

The county and its partners developed comprehensive load reduction plans which address multiple pollutants and have a compliance timeframe of 20 years for wet weather conditions. The plans were developed by water quality consultants and used computer modeling to identify potential actions and the estimated cost to achieve compliance.

The county’s estimated cost will be between $286 million and $567 million; possible actions include construction of capital improvement projects to treat stormwater before it is discharged to creeks and beaches, increased monitoring of affected water bodies to demonstrate water quality improvement, and augmenting existing pollution prevention programs which target behavior change.

The cost estimates are based on the premise that any structural projects would be built on publicly-owned land; the costs would increase if private property is determined to be necessary to meet TMDL targets. The plans state that the responsible parties are only able to implement the actions if resources are identified, although if the RWQCB does not modify the bacteria limitations prior to the compliance dates and the results do not meet the TMDL requirements the county can be fined up to $10,000 per day per occurrence and the RWQCB could also require improvements to be made under threat of substantial fines and with reimbursement of RWQCB staff time for oversight.

The county currently spends approximately $35 million annually to comply with its current National Pollutant Discharge Elimination System permit while the county’s 21 total entities (including the Port District and the Airport Authority as well as the county and 18 incorporated cities) spend more than $100 million annually. The estimated compliance cost to all 21 agencies for attainment of the TMDL standards is between $2.2 billion and $4.2 billion.

Although the compliance measures are intended to meet the bacteria TMDL requirements, the RWQCB is expected to impose TMDL requirements on nutrients, sediment, metals, and other pollutants in the future. The RWQCB is expected to renew the county’s National Pollutant Discharge Elimination System permit in April 2013 and will likely include either current or revised TMDL standards.

The county, the cities of Oceanside and Vista, and the California Department of Transportation are the responsible parties for the San Luis Rey Watershed. The estimated cost of compliance over 18 years is between $127 million and $277 million with the county’s portion of the cost estimated at between $62 million and $105 million.

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