ITEM: 5

SUBJECT: CONSIDERATION OF 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)

DISCUSSION: Southern California Edison Company (SCE) owns and operates the SONGS power plant located on the Pacific Coast in northern San Diego County. The plant consists of two twin generating units (Units 2 and 3; an older Unit 1 is no longer in operation) with separate cooling systems. 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 1/2 to 1-1/2 miles offshore. The two units have operated since the mid-1980s under separate discharge permits issued by the San Diego Regional Water Quality Control Board (SDRWQCB). Each is rated at approximately 1180 megawatts and discharges approximately 1,200 million gallons of heated sea water per day.

The SONGS discharges are subject to the Thermal Plan with respect to the thermal component of the discharge. As required by the Thermal Plan, the SONGS discharge permits specify that the effluent from Units 2 and 3 may not exceed the receiving water temperature by more that 20° F (this temperature difference is generally referred to as DT--"delta T"). SONGS has operated with this limitation since Units 2 and 3 began operations in the early 1980s.

In 1997, SCE, claiming that a general loss of efficiency of the SONGS cooling system over the years had reduced the plant's ability to generate full rated power while complying with the 20° F DT limitation, asked the SDRWQCB for an exception to the SONGS discharge permits to raise the discharge DT to 25°F. This higher limitation, according to SCE, would allow the two SONGS units to again generate their rated power, particularly during the summer when the impacts of the system's deterioration have placed greatest constraints on power production.

The Thermal Plan specifies that a Regional Water Quality Control Board (RWQCB) may grant an exception to specific water quality objectives of the Thermal Plan in accordance with Section 316(a) of the Federal Clean Water Act (CWA). Any exceptions granted by an RWQCB must receive the concurrence of the State Water Resources Control Board (SWRCB) before becoming effective. On

February 11, 1998, following a public hearing, the SDRWQCB approved the exceptions for the two SONGS permits as requested and adopted a California Environmental Quality Act Negative Declaration on its action. The issue is now being presented to SWRCB for concurrence.

The requirements to be met by an applicant for an exception to thermal discharge limitations and by a state considering granting such an exception are given in CWA Section 316(a) and associated regulations, particularly 40 Code of Federal Regulations Chapter 1. Under Section 316(a), the applicant has the opportunity to demonstrate to the satisfaction of the State that the proposed exception will assure the protection and propagation of a balanced indigenous population of shellfish, fish, and wildlife in the affected water body. Based on the applicant's demonstration, the State may then grant such an exception. Any exception granted under Section 316(a) must be reviewed at the time of permit renewal (every five years in this case).

SWRCB staff has reviewed the record of this action submitted by the SDRWQCB and has concluded that the available evidence indicates that balanced indigenous communities of marine life are being maintained and will be maintained in the vicinity of SONGS after implementation of the Thermal Plan exception as adopted by the SDRWQCB. Staff therefore recommends that the SWRCB approve the exception.

POLICY ISSUE: Should the SWRCB concur in and approve the SDRWQCB action granting new 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.

FISCAL IMPACT: NONE

RWQCB IMPACT: Yes, SDRWQCB.

STAFF RECOMMENDATION: That the SWRCB concurs in and approves the SDRWQCB action granting new 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.

January 25, 1999 DRAFT

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.

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.

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 that applicants for exceptions to thermal discharge limitations demonstrate that the existing limitations are more stringent than necessary to protect and maintain balanced indigenous communities in the affected water body.

7. SCE has provided information which demonstrates that the proposed limitation will protect and maintain balanced indigenous communities in the affected area of the Pacific Ocean.

8. On February 11, 1998, following a public hearing, SDRWQCB approved the exceptions for the two SONGS permits as requested by SCE and adopted a California Environmental Quality Act 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 new 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.

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 February 18, 1999.

_____________________________________

Maureen Marché

Administrative Assistant to the Board