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Home My WebLink About09/06/1988, 1 - REQUEST FOR MODIFICATION OF DISCHARGE REQUIREMENTS AND BASIN PLAN STANDARDS ��nII111111111118111111II��I��I�lllllllllll11 IIIII�I city ofsAn tuts oBispo 990 Palm Street/Post Office Box 8100 • San Luis Obispo, CA 93403-8100 July 15, 1988 Mr. William Leonard Executive Officer California Regional Water Quality Control Board, Central Coast Region 1102-A Laurel Lane San Luis Obispo, CA 93401 Subject: Request for Modification of Discharge Requirements and Basin Plan Standards Dear Mr. Leonard: The San Luis Obispo City Council in its meeting on July 5, 1988, directed me to submit to the Regional Water Quality Control Board findings of the Wastewater Reclamation/Beneficial Use Investigation Report and to request relaxation of discharge requirements and Basin Plan Standards for the protection of San Luis Obispo Creek. The Wastewater Reclamation/Beneficial Use Investigation report was prepared by our consultant, Brown and Caldwell, on the direction of the City Council and previously submitted to you for review and comment. The principal objectives of this report were to investigate potential of high quality plant effluent for beneficial uses and identification of alternate methods to achieve equivalent protection of the San Luis Obispo Creek. As we indicated to you previously in our letter dated February 25, 1988, the treatment facilities recommended in the October 1987 Wastewater Management Plan will easily meet discharge requirements for BODS, suspended solids, unionized ammonia-nitrogen, coliform bacteria and other constituents. The plant may have difficulty, however, meeting some of the current receiving water criteria that are incorporated into the discharge requirements from the Water Quality Control Plan for the Central Coast Basin Plan. These include requirements for turbidity, color, MBAS, temperature and pH. The treatment system that would be needed to meet these requirements might include chemical coagulation-flocculation- clarification., filtration and/or activated carbon. Addition of these processes to meet the stringent receiving water limits would increase the treatment costs several-fold, resulting in unbearable burden on the tax-payers. Accordingly, after several discussions with you and with other Regional Board staff members, the City directed Brown and Caldwell to study an overall resource management approach of San Luis Obispo � : 30 �Zoe Page 2 Creek as an alternative to achieve an equivalent level of environmental protection through reclamation and beneficial use projects. Four beneficial use options were evaluated as briefly summarized below. 1. Stream Enhancement - This option includes the reestablishment of riparian vegetation, construction of instream structures to improve. steelhead habitat and terracing of the bank slope to provide for flood flows. 2. Landscape Irrigation - This option includes irrigation of golf courses, parks, and commercial and road-side landscaping by reclaimed water. A higher level of treatment than that recommended in the Wastewater Management Plan is required. 3. Agricultural Irrigation - This option includes the use of reclaimed water for irrigation of agriculture crops. Different levels of treatment are required for agricultural irrigation depending on the type of crop. 4. Indirect Discharge to Lacruna Lake - This option involves the discharge of reclaimed water to holding ponds above Laguna Lake and allowing the water to percolate into the lake. This would provide increased flow into the lake during the summer time to maintain a higher lake level. After a detailed review of the above options, the City has adopted stream enhancement and landscape irrigation projects as alternate ways to provide equivalent overall environmental benefits. The stream enhancement project involves a 4000-foot reach of San Luis Obispo Creek on the Pereria property just south of the treatment plant. The project would consist of (1) reestablishment of riparian vegetation along the creek corridor; (2) temporary fencing of the corridor to keep cattle out until the vegetation becomes established; (3) construction of instream structures to improve steelhead habitat; (4) irrigation of the riparian vegetation for two to three years until it becomes established; and (5) providing terracing or shaving of the bank slope to increase the channel cross-section. Bank stabilization at selected locations may also be an element of the project. This stream enhancement concept is strongly supported by the San Luis Obispo County Land Conservancy. The landscape irrigation project involves irrigation of approximately 180 acres at the proposed business parks and golf course envisioned in the Airport Area Specific Plan currently being prepared by the County. A side stream of about 1.0 mgd of filtered plant effluent will be used for the irrigation of the landscaped areas. As plans for the development of the Airport Area become more well defined, additional parks and playgrounds may be irrigated with' filtered plant effluent. /- 3 Page 3 As you know, the City has begun implementation of its Wastewater Management Plan. A $1.2 million design contract has been authorized and a 90 percent sewer rate increase has been adopted. The City has also directed its consultant to develop stream enhancement and landscape irrigation projects. We believe that these projects will provide improved habitat for steelhead trout, improve habitat for wildlife, and provide a visually pleasing riparian corridor and green landscape areas. Therefore, the City requests that the Regional Board take immediate steps to modify the Basin Plan for changes in waste discharge requirements for the five constituents listed in Table 1. We would be pleased to discuss our approach and proposed receiving water requirements with you at your convenience. We are looking forward to your assistance and support in a temly manner so that the City can continue with confidence with the implementation of its Wastewater Management Plan and beneficial reuse options for overall environmental benefits of the San Luis Obispo Creek. As we requested previously, we would like to be included in the August Agenda of the Regional Board for discussion on this manner. Very truly yours, William T. Hetland Utilities Manager c: D. Romero T. Ross modisc/wth4 jj � : 30