ITEM: 3

SUBJECT: CONSIDERATION OF APPROVAL OF AN AMENDMENT TO THE WATER QUALITY CONTROL PLAN FOR THE SANTA ANA RIVER BASIN ESTABLISHING A TOTAL MAXIMUM DAILY LOAD FOR NUTRIENTS IN THE NEWPORT BAY/ SAN DIEGO CREEK WATERSHED

DISCUSSION: The Water Quality Control Plan for the Santa Ana River Basin (Basin Plan) was adopted by the California Regional Water Quality Control Board, Santa Ana Region (SARWQCB) on March 11, 1994, and approved by the State Water Resources Control Board (SWRCB) on July 21, 1994, and by the Office of Administrative Law (OAL) on January 24, 1995. On October 31, 1997, the U.S. Environmental Protection Agency, Region 9 (U.S. EPA), entered into a consent decree (Decree) with Defend the Bay, Inc., which required that the State develop nutrient and sediment Total Maximum Daily Loads (TMDLs) by January 15, 1998 for the Newport Bay/ San Diego Creek Watershed (Watershed). The Decree stipulated that U.S. EPA would establish the required TMDLs within ninety days if the State failed to establish approved TMDLs by the Decree deadline.

The SARWQCB did not approve a nutrient TMDL for the Watershed by the January 15, 1998 deadline. As required by the Decree, on February 27, 1998, the U.S. EPA promulgated a nutrient TMDL for the Watershed. The U.S. EPA nutrient TMDL became effective on April 13, 1998. On April 17, 1998, the SARWQCB adopted Resolution No. 98-09 (Attachment 1-- not electronically available) amending the Basin Plan by establishing a nutrient TMDL for the Watershed consistent with that promulgated by U.S. EPA. Maps of the Watershed are provided in Attachments 2 and 3 (not electronically available).

The beneficial uses and nutrient water quality objectives for Newport Bay (Bay) and San Diego Creek are presented in Attachment 4. The Bay has exhibited signs of nutrient enrichment for approximately twenty-five years. Large mats of the green algae Ulva, Enteromorpha, and Cladophora have been commonplace in the Bay, with a peak bloom occurring in 1985-86. The life cycle of these algae has negatively impacted the habitat and recreational beneficial uses of the Bay. In May 1986, a fish kill in the Newport Island area due to anoxic conditions (dissolved oxygen [DO] near zero milligrams/liter [mg/l]) was attributed to decomposing algae. Recent consultant studies in the Upper Newport Bay (Upper Bay) indicated that areas with high algal biomass have been subject to periodically depressed levels of DO (less than 3 mg/l) that could impact habitat beneficial uses.

The nutrients which are responsible for algal growth are nitrogen and phosphorus. Studies undertaken both independently and cooperatively by staff of the SARWQCB and the Orange County Environmental Management Agency between 1980 and 1994 determined that approximately 80 percent of the nitrate-nitrogen loading to the Bay was from Peters Canyon Wash (see Attachment 2). Three commercial nurseries and other agricultural sources located in the Peters Canyon Wash were identified as the major contributors of nutrients to the Bay. In 1987, the three commercial nurseries were allocated a percentage of the average daily load of nitrate-nitrogen discharged to the Bay from San Diego Creek. The nurseries were able to reduce their contribution to the average daily load of nitrate-nitrogen by 32 percent through the use of Best Management Practices (BMPs) (e.g., reduction of runoff, reuse of irrigation return water, use of computerized drip irrigation systems). The nursery wasteload allocations were formalized with the issuance of waste discharge requirements (WDRs) by the SARWQCB in July 1990. The Irvine Company (the major land owner in the Watershed) also implemented various BMPs on their agricultural lands consisting mainly of erosion control, drainage improvements, and drip irrigation.

A number of discharge sources have WDRs that include specific effluent limits for nitrogen compounds. The Orange County Areawide Urban Stormwater Permit does not include specific effluent limits for nitrogen compounds. Other potential and existing point sources include: (1) the Irvine Ranch Water District Wetlands Water Supply Project, (2) the proposed discharge of dewatered ground water by Silverado Constructors from the Eastern Transportation Corridor project to Peters Canyon Wash, and (3) numerous small nurseries not currently under permit for discharge to surface waters. The nonpoint sources in the watershed are mainly agricultural operations and open space areas, especially during storm events.

The proposed TMDL specifies daily, seasonal, and/or annual targets and Load Allocations for the Watershed and San Diego Creek (Reach 2) (Attachment 1). The total nitrogen TMDL for the Watershed is based on a 50 percent reduction in current "low-flow" loading of total nitrogen to the Bay. By definition, "low-flow" is when the mean daily flow rate in San Diego Creek at Campus Drive [Attachment 2] is less than 50 cubic feet per second [cfs] or if greater than 50 cfs is not the result of precipitation. Nitrogen deposition resulting from storm flows above 50 cfs was found to provide a minimal contribution to nitrogen loading in the Bay. This reduction in "low-flow" nitrogen loading to the Upper Bay would result in approximately the same condition observed in the early 1970s when algal growth in the Upper Bay was less prevalent, and the narrative water quality objective was being attained.

The total phosphorus TMDL is based on a 50 percent reduction in phosphorus loading to the Bay. Because phosphorus is associated with clay and silt sediment particles, the 50 percent reduction in erosion and sedimentation required by the Sediment TMDL (SARWQCB Resolution No. 98-69) should provide the required reduction in the phosphorus loading.

Current loadings of total inorganic nitrogen (TIN) in San Diego Creek (Reaches 1 and 2) exceed the water quality objectives. The 50 percent reduction in nutrient loading required for San Diego Creek at Campus Drive (see Attachment 2) will provide compliance with the TIN objective for Reach 1, but not for Reach 2. As such, the total nitrogen daily load for Reach 2 was determined based on the tenth percentile flow rate of San Diego Creek at the Culver Drive Station (0.5 cfs) and the amount of TIN load that would equal the existing water quality objective.

Phase I of the nutrient TMDL establishes compliance schedules for the following activities: (1) review and revision of water quality objectives for TIN for San Diego Creek Reaches 1 and 2; (2) establishment of WDRs for nursery operations of five acres or more which discharge nutrients in excess of 1 mg/l TIN to tributaries to the Bay; (3) revision of existing WDRs for nursery operations currently discharging nutrients in excess of 1 mg/l TIN to drainages tributary to the Bay; (4) revision of National Pollutant Discharge Elimination System (NPDES) permits for discharges of nutrients in excess of 1 mg/l TIN to drainages tributary to the Bay; (5) revision of monitoring and reporting programs in existing WDRs and NPDES permits for groundwater dewatering and cleanup operations which discharge to drainages tributary to the Bay; and (6) submission by co-permittees of the Orange County Areawide Urban Stormwater Permit (SARWQCB Order No. 96-31) of an analysis of BMPs to achieve the short-term (five year) interim targets and final nutrient load targets and a proposal for evaluating the effectiveness of the control actions implemented subject to approval by the SARWQCB Executive Officer.

Phase II of the TMDL requires the SARWQCB to establish and oversee a regional monitoring program (RMP) for the Watershed. The objectives of the RMP are to quantify the three endpoints of the TMDL: (1) the seasonal nutrient loadings from the Watershed; (2) the nutrient concentrations in the San Diego Creek, Reaches 1 and 2; and (3) the extent, magnitude, and duration of any algal blooms in San Diego Creek and the Bay.

POLICY ISSUE: Should the SWRCB approve SARWQCB Resolution No. 98-09 amending the Water Quality Control Plan for the Santa Ana River Basin?

FISCAL IMPACT: SARWQCB and SWRCB staff work associated with, or resulting from this action, can be accommodated within budgeted resources.

RWQCB IMPACT: Yes, SARWQCB.

STAFF RECOMMENDATION: That the SWRCB:

1. Approve SARWQCB Resolution No. 98-09 amending the Water Quality Control Plan for the Santa Ana Region.

2. Authorize staff to submit the approved Basin Plan amendment to the U.S. EPA and regulatory provisions to OAL for approval.

Note: Attachments 1, 2 and 3 are not available electronically. For copies, contact:

Steve Fagundes/Division of Water Quality/State Water Resources Control Board/P.O. Box 944213/Sacramento, CA 94244-2130/(916) 657-0914 or FAX (916) 654-8375

May 4, 1998 Draft

WHEREAS:

1. The California Regional Water Quality Control Board, Santa Ana Region (SARWQCB) adopted a revised Water Quality Control Plan for the Santa Ana River Basin (Basin Plan) on March 11, 1994.

2. The Basin Plan includes a narrative objective for nutrients in Newport Bay and narrative and numerical objectives for the San Diego Creek Watershed which are not being met and beneficial uses have been adversely impacted. The SARWQCB has listed Newport Bay and San Diego Creek as being water quality limited in accordance with Section 303(d) of the Federal Clean Water Act (CWA).

3. Section 303(d) requires the establishment of the Total Maximum Daily Load (TMDL) of nutrients that can be discharged while still ensuring compliance with water quality standards. Section 303(d) also requires the allocation of the TMDL among the sources of nutrients (Load Allocations) and an implementation plan and schedule that will ensure that compliance with water quality standards will be achieved.

4. On April 17, 1998, the SARWQCB adopted Resolution No. 98-09 (Attachment 1) amending the Basin Plan by establishing a TMDL for nutrients discharged in the Newport Bay/San Diego Creek Watershed.

5. The State Water Resources Control Board (SWRCB) finds that the proposed Basin Plan amendment is in conformance with the requirements for TMDL development specified in CWA Section 303(d).

6. The SWRCB finds that the proposed amendment complies with requirements of SWRCB Resolution No. 68-16 (Statement of Policy with Respect to Maintaining High Quality of Waters in California).

7. Section 13240 of the Water Code specifies that basin plans be periodically reviewed and, if appropriate, revised.

8. The SARWQCB staff prepared documents and followed procedures satisfying environmental documentation requirements in accordance with the California Environmental Quality Act and other State laws and regulations.

9. This Basin Plan amendment does not become effective until approved by the SWRCB and the U.S. Environmental Protection Agency (U.S. EPA) and until the regulatory provisions are approved by the Office of Administrative Law (OAL).

THEREFORE BE IT RESOLVED THAT:

The SWRCB:

1. Approves SARWQCB Resolution No. 98-09 amending the Basin Plan by establishing a TMDL for nutrients discharged in the Newport Bay/San Diego Creek Watershed.

2. Authorizes SWRCB staff to submit the approved Basin Plan amendment to the U.S. EPA and the regulatory provisions to OAL for approval.

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 May 13, 1998.

_____________________________________

Maureen Marché

Administrative Assistant to the Board