STATE WATER RESOURCES CONTROL BOARD

RESOLUTION NO. 99 - 028

APPROVAL OF THE SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD's ADOPTION OF AN EXCEPTION TO THE CALIFORNIA STATE THERMAL PLAN (THERMAL PLAN) FOR SAN ONOFRE NUCLEAR GENERATING STATION (SONGS)

 WHEREAS:

 1.Southern California Edison Company (SCE) owns and operates the SONGS power plant located on the Pacific Coast in northern San Diego County. SONGS consists of two active units, each discharging approximately 1,200 million gallons per day of heated sea water to the Pacific Ocean. The two active units employ once-through cooling water systems, withdrawing cooling water from the Pacific Ocean and discharging it to the ocean through separate underwater diffusers situated on the ocean bottom approximately ½ to 1½ miles offshore. Each underwater diffuser is 762 meters long, with 63 diffuser ports. The Unit 2 diffuser ends 2500 meters from shore in approximately 15 meters of water. The Unit 3 diffuser ends 1800 meters from shore in approximately 12 meters of water. The diffusers are placed such that sensitive near shore marine habitat, especially intertidal and shallow subtidal habitat, will not be affected by heat from the discharge.

2. The SONGS discharges operate under separate discharge permits issued by the
San Diego Regional Water Quality Control Board (SDRWQCB) and are subject to the Thermal Plan with respect to the thermal component of the discharges. SONGS has complied with the thermal limitations of its discharge permits.

3.The Thermal Plan and the SONGS discharge permits require that the effluent from SONGS Units 2 and 3 may not exceed the receiving water temperature by more than 20°F.

4. The Thermal Plan and the Federal Clean Water Act (CWA) specify that a Regional Water Quality Control Board may grant an exception to specific water quality objectives of the Thermal Plan with concurrence from the State Water Resources Control Board (SWRCB) and in compliance with Section 316(a) of the CWA and associated federal regulations.

5. In May 1997, SCE applied to SDRWQCB for exceptions to the limitation in No. 3 above, so as to allow discharges from Units 2 and 3 to exceed the receiving water temperature by no more than 25° F.

6. CWA Section 316(a) requires an applicant for an exception to thermal discharge limitations to demonstrate that the existing limitations are more stringent than necessary to protect and maintain balanced indigenous communities in the affected water body, taking into account the interaction of such thermal component with other pollutants. Title 40 Federal Code of Regulations section 125.73 requires the applicant for the exception to demonstrate either "that no appreciable harm has resulted" from the discharge, or that "despite the occurrence of such previous harm, the desired alternative effluent limitations will nevertheless assure the protection and propagation of a balanced, indigenous community of shellfish, fish and wildlife in and on the body of water into which the discharge is made."

7. SCE has provided information which demonstrates that the proposed limitation will protect and maintain balanced indigenous communities in the vicinity of the SONGS discharges based on a number of considerations:

a. While there is evidence of impacts caused by entrainment and discharge-induced turbidity, there is no evidence of adverse impacts caused by the thermal component of the discharge.

b. Effects due to the proposed increase in temperature will be minimal because the discharge structures are designed and placed such that sensitive near shore marine habitat, especially intertidal and shallow subtidal habitat, will not be affected by heat from the discharge. Further, thermal plume modeling of the new discharge conditions as reported in SDRWQCB's Initial Study shows clearly that permit requirements will not be violated as a result of the requested permit modification, and that thermal impacts on the sensitive kelp bed environment will be insignificant.

c. Previous impacts to the marine ecosystem caused by other components of the discharge will be addressed by the mitigation measures mandated by the California Coastal Commission.

8. On February 11, 1998, after conducting and publishing a California Environmental Quality Act (CEQA) Initial Study of the requested exception and following a public hearing, SDRWQCB approved the exceptions for the two SONGS permits as requested by SCE. SDRWQCB found that SCE had adequately demonstrated that balanced indigenous communities would be maintained in the vicinity of SONGS if the requested amendment were granted. SDRWQCB adopted a CEQA Negative Declaration on its action.

9. SWRCB staff has reviewed the SDRWQCB action and found that the action complies with State and federal criteria for granting an exception to the Thermal Plan's discharge limitation.

THEREFORE BE IT RESOLVED THAT:

The SWRCB concurs in and approves the SDRWQCB action granting amended discharge limitations to SONGS Units 2 and 3. These limitations must be reviewed by SDRWQCB at the time of renewal of the SONGS Units 2 and 3 discharge permits with a view to assuring that balanced indigenous communities of marine life are being maintained in the vicinity of the SONGS discharges.

CERTIFICATION

 The undersigned, Administrative Assistant to the Board, does hereby certify that the foregoing is a full, true, and correct copy of a resolution duly and regularly adopted at a meeting of the State Water Resources Control Board held on April 14, 1999.

  /s/

Maureen Marché

Administrative Assistant to the Board