CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD

PURPOSE OF ORDER

1. North San Mateo County Sanitation District (hereinafter referred to as NSMCSD) submitted a Report of Waste Discharge for re-issuance of waste discharge requirements and a permit to discharge wastewater to waters of the State and the United States under the National Pollutant Discharge Elimination System (NPDES).
2. This discharge was previously regulated by Waste Discharge Requirements in Order No. 94-140, adopted by the Board on September 21, 1994.

FACILITY DESCRIPTION

3. The discharger owns and operates the treatment plant located at Daly City (Attachment A). The plant provides secondary level treatment for domestic and commercial wastewater from the City of Daly City and portions of San Mateo County, the Town of Colma, San Francisco County Jail and the Westborough Water District within the City of South San Francisco. The discharger's service area has a present population of 120,027. The treatment plant has an average dry weather flow design of 8.0 million gallons per day (mgd), and can treat up to 25 mgd during the wet weather flow period. The plant presently discharges an annual average flow of 6.85 mgd.
4. The U.S. Environmental Protection Agency (USEPA) and the Board have classified this discharge as a major discharger.
5. Wastewater treatment consists of influent coarse bar screening, primary sedimentation with flow equalization, secondary treatment and sedimentation, chlorination and dechlorination. Flow equalization is only used when necessary. A treatment process schematic diagram is included as Attachment B.
6. Treated wastewater is currently discharged into the Pacific Ocean, a water of the State and United states, through the Vista Grande Tunnel structure and a 27" force main located on Ocean Beach, San Francisco County, through a submerged diffuser about 2,500 feet from the outfall structure on the beach. The diffuser is located at a depth of 32 feet below water (latitude 37 deg. 42 min. 48 sec.; longitude 122 deg. 30 min. 50 sec.), with an initial dilution ratio of 70:1.
7. Sludge is treated by gravity thickeners, air floatation thickeners, anaerobic digesters, and centrifuges with final disposal to a sanitary landfill or to a qualified biosolids reuse facility or project. The Regional Board will be notified in advance of any changes in disposal of the material.

APPLICABLE PLANS AND POLICIES

8. The State Water Resource Control Board adopted a revised "Water Quality Control Plan for the Ocean Waters of California" (California Ocean Plan) on July 23, 1997.

PRETREATMENT PROGRAM

9. On June 17, 1983, the discharger’s Pretreatment Program received final approval by the EPA. By letter dated January 4, 1995, the discharger requested that its Pretreatment Program be removed from the Federal Pretreatment Program Requirements.
10. Pursuant to 40 Code of Federal Regulations (CFR) Part 403, the discharger is required to develop and implement an approved Pretreatment Program. However, all discharges to the treatment plant are either residential flows or commercial flows that are similar in quality and quantity to residential discharges. Therefore, the discharger had been determined to not meet the criteria of having to implement a local pretreatment program and was removed and deleted from having to maintain an approved pretreatment program in Order No. 95-015. This Order continues to find that the discharger is not required to implement an approved pretreatment Program

BENEFICIAL USES

11. The Ocean Plan contains water quality objectives and beneficial uses for the Pacific Ocean. The beneficial uses of the Pacific Ocean are as follows:

CHRONIC TOXICITY

12. In 1986 the Board initiated the Effluent Toxicity Characterization Program (ETCP) in which certain major dischargers (including NSMCSD) were required to monitor their effluent using critical life stage toxicity tests to generate information on toxicity testing for species sensitivity and effluent variability to allow development of appropriate chronic toxicity effluent limitations.

The result from the ETCP shows that NSMCSD currently does not need chronic toxicity limitations; however, this permit may be amended in the future to include chronic toxicity effluent limits and monitoring requirements.

STORMWATER

13. Federal Regulations for stormwater discharges were promulgated by the U.S. Environmental Protection Agency on November 19, 1990. The regulations [40 CFR Parts 122, 123, and 124] require specific categories of industrial activities including Publicly Owned Treatment Works (POTWs) which discharge storm water associated with industrial activity (industrial stormwater) to obtain an NPDES permit and to implement Best Available Technology Economically Available (BAT) and Best Conventional Pollutant Control Technology (BCT) to control pollutants in industrial stormwater discharges.


Stormwater flows from the wastewater treatment facility process areas are directed to the headworks of the treatment plant. These flows are exempt from industrial stormwater permitting based on U.S. EPA March 12, 1992 Q&A Guidance.

OTHER FINDINGS

14. An Operations and Maintenance Manual is maintained by the Discharger for purposes of providing plant, collection system, and regulatory personnel with a source of information describing all equipment, recommended operation strategies, process control monitoring, and maintenance activities. In order to remain a useful and relevant document, the manual must be kept updated to reflect significant changes in treatment and collection facility equipment and operation practices.
15. This Order serves as an NPDES permit, adoption of which is exempted from the provisions of Chapter 3 (commencing with Section 21100) of Division 13 of the Public Resources Code [California Environmental Quality Act (CEQA)] pursuant to Section 13389 of the California Water Code.

NOTIFICATIONS AND MEETINGS

16. The Discharger and interested agencies and persons have been notified of the Board's intent to reissue requirements for the existing discharge and have been provided an opportunity to submit their written views and recommendations.
17. The Board, in a public meeting, heard and considered all comments pertaining to the discharge.

IT IS HERE BY ORDERED, pursuant to the provisions of Division 7 of the California Water Code and regulations adopted thereunder, and the provisions of the Clean Water Act and regulations and guidelines adopted thereunder, that the discharger shall comply with the following:

1. DISCHARGE PROHIBITIONS

1. Discharge of treated wastewater at locations or in a manner different from that described in Findings 5, 6, 7 and 12 is prohibited.
2. The average dry weather flow discharge shall not exceed 8.0 mgd. The average dry weather flow shall be determined over three consecutive dry weather months each year.
3. Discharge of water, materials or wastes which are not otherwise authorized by this NPDES permit, to a storm drain system or waters of the State are prohibited.
4. The discharge of municipal and industrial waste sludge either directly or indirectly to the ocean, or into a waste stream that discharges to the ocean, is prohibited. The discharge of sludge digestion supernatant directly to the ocean, or into a waste stream that discharges to the ocean without further treatment is prohibited.
5. Discharge shall be essentially free of material that is floatable or will become floatable upon discharge.
6. Discharge shall be essentially free of settleable material or substances that may form sediments which will degrade benthic communities or other aquatic life.
7. Discharge shall be essentially free of substances that will accumulate to toxic levels in marine waters, sediments or biota.
8. Discharge shall be essentially free of substances that significantly decrease the natural light to benthic communities and other marine life.
9. Discharge shall be essentially free of materials that result in aesthetically undesirable discoloration of the ocean surface.

The term "effluent" in the following limitations means the fully treated wastewater effluent from the discharger's wastewater treatment facility, as discharged to the Pacific Ocean.

1. The effluent discharged to the Pacific Ocean shall not exceed the following limitations:

2. pH: The pH of the discharge shall not exceed 9.0 nor be less than 6.0.

3. Total Coliform Bacteria:
The treated wastewater, at some place in the treatment process prior to discharge, shall meet the following limits of bacteriological quality: The moving median value for the Most probable Number (MPN) of total coliform bacteria in any five (5) consecutive samples shall not exceed 2400 MPN/100 ml. In addition, any single sample shall not exceed 24,000 MPN/100 ml.

4. 85 Percent Removal, BOD and TSS:
The arithmetic mean of the biochemical oxygen demand (five-day, 20OC) and total suspended solids values, by weight, for effluent samples collected in each calendar month shall not exceed 15 percent of the arithmetic mean of the respective values, by weight, for influent samples collected at approximately the same times during the same period.

5. Interim Total Coliform Bacteria Limit: Effluent Limitation B.3 (Total Coliform Bacteria) shall be suspended during the bacterial Assessment Study period as proposed in Provision E.9. During the study period, the discharger shall comply with Coliform requirements specified in Receiving Water Limitations C.5.

The discharge of waste shall not cause the following conditions to exist in waters of the State. Compliance shall be determined from samples collected at stations representative of the area within the waste field where initial dilution is completed.

3. Biological Characteristics
   

Marine communities, including vertebrate, invertebrate, and plant species, shall not be degraded. The natural taste, odor, and color of fish, shellfish, or other marine resources used for human consumption shall not be altered. The concentration of organic materials in fish, shellfish or other marine resources used for human consumption shall not bioaccumulate to levels that are harmful to human health

4. Radioactivity
   Discharge of radioactive waste shall not degrade marine life.
   
   
5. Bacterial Characteristics

Within a zone bounded by the shoreline and a distance of 1,000 feet from the shoreline or the 30-foot depth contour, whichever is further from the shoreline, and in areas outside this zone used for water contact sports, as determined by the Regional Board, the following bacteriological objectives shall be maintained throughout the water column: Samples of water from each sampling station shall have a concentration of total coliform organisms less than 1,000 per 100 ml; provided that not more than 20 percent of the samples at any sampling station, in any 30-day period, may exceed 1,000 per 100 ml, and provided further that no single sample when verified by a repeat sample taken within 48 hours shall exceed 10,000 per 100ml. The fecal coliform concentration based on a minimum of not less than five samples for any 30 day period, shall not exceed a geometric mean of 200 per 100 ml nor shall more than 10 percent of the total samples during any 60 day period exceed 400 per 100 ml.

6. Shellfish Harvesting

1. Permit Rescission: Requirements prescribed by this order supersede the requirement prescribed by Order No.94-140. Order No. 94-140 is hereby rescinded.
2. Mass Emission Limitations: Where concentration limitations in mg/l or mg/l are contained in this permit, Mass Emission Limitations, determined in accordance with the attached Standard Provisions, Section G (Definitions), Paragraphs 12 and 13, shall also apply
3. Treatment Facility Performance Goals: The performance goals are based upon the performance of the discharge facility and are used only as an indication of the efficiency of the treatment facility. They are not considered as limitations for the regulation of the treatment facility.

The Regional Board believes that the discharger should make every reasonable effort to maintain the following treatment facility performance goals (performance goals).

Any exceedance of performance goals will not be considered a violation of this Order and shall be reported in the monthly report to the Regional Board.

In case of an exceedance, the discharger shall increase effluent sampling for the constituent in exceedance of the performance goal in accordance with the sampling frequency increase provisions specified in Part B, Table 1, Footnotes 4 and 8. The increased monitoring shall continue until the sampling results no longer show an exceedance of the performance goal.

In the report to the regional board, the discharger shall document the constituent in exceedance, the duration and the cause of exceedance, and any mitigation or correction action to prevent future exceedances.

The performance goals are as follows:

Constituent		Units	Monthly Average	Maximum at any time
a.	Oil and Grease	mg/l	10	20
b.	Settleable Solids	ml/l-hr	0.1	0.2
c.	Total Chlorine Residual	mg/l	--	0.0

4. Permit Compliance: The Discharger shall comply with all sections of this Order immediately upon adoption.
5. Effluent Monitoring: The Discharger shall initiate a monitoring program using appropriate USEEPA methods and detection limits, to evaluate the compliance status for all constituents listed in Effluent Limitations in Section B. Monitoring for constituents shown in Section B shall be performed during all periods of surface water discharge.
6. Operations and Maintenance Manual: The discharger shall review, and update as necessary, its Operations and Maintenance Manual, annually, or within 90 days of completion of any significant facility or process changes. The discharger shall submit to the Board, by April 15 of each year, a letter describing the results of the review process including an estimated time schedule for completion of any revisions determined necessary, and a description or copy of any completed revisions.
7. Contingency Plan: Annually, the discharger shall review and update as necessary, its Contingency Plan as required by Board Resolution 74-10 (Attachment C). The discharge of pollutants in violation of this Order where the discharger has failed to develop and/or adequately implement a contingency plan will be the basis for considering such discharge a willful and negligent violation of this Order pursuant to Section 13387 of the California Water Code. Plan revisions, or a letter stating that no changes are needed, shall be submitted to the Board by April 15 of each year.
8. Treatment Facilities Evaluation Program: The Discharger shall implement a program to regularly review and evaluate its wastewater collection, treatment and disposal facilities in order to ensure that all facilities are adequately staffed, supervised, financed, operated, maintained, repaired, and upgraded as necessary, in order to provide adequate and reliable transport, treatment, and disposal of all wastewater from both existing and planned future wastewater sources under the discharger's service responsibilities. A Treatment Facilities Evaluation Program report discussing the status of this evaluation program, including any recommended or planned action, shall be submitted to the Board by April 15 of each year.
9. Bacterial Assessment Study: The Discharger shall conduct a Bacterial Assessment Study in accordance with a schedule established in the Monitoring Plan and agreed to by the Executive Officer, and in accordance to Chapter II.B of the Ocean Plan.




Submit Monitoring proposal by:	May 31, 2000
Submit Monitoring Plan by:	August 31, 2000
Submit Status Report:	Quarterly
Submit Final Report:	May 31, 2005



10. Self-monitoring Program: The Discharger shall comply with the Self-Monitoring Program (Attachment D) for this order, as adopted by the Board and as may be amended by the Executive Officer.
11. Standard Provisions and Reporting Requirements: The Discharger shall comply with all applicable items of the ''Standard Provisions and Reporting Requirements" dated August 1993 (Attachment E).
12. Change in Control or Ownership: In the event of any change in control or ownership of land or waste discharge facilities presently owned or controlled by the Discharger, the Discharger shall notify the succeeding owner or operator of the existence of this Order by letter, a copy of which shall be immediately forwarded to this office.
13. Permit Transfer: To assume operation of this Order, the succeeding owner or operator must apply in writing to the Executive Officer requesting transfer of the Order. (Refer to Standard Provisions, referenced above). The request must contain the requesting entity's full legal name, the address and telephone number of the persons responsible for contact with the Board and a Statement. The statement shall comply with the signatory paragraph described in the Standard Provisions and state that the new owner or operator assumes full responsibility for compliance with this Order. Failure to submit the request shall be considered a discharge without requirements, a violation of the California Water Code.
14. Permit Expiration: This Order expires on March 15, 2005. The discharger must file a report of waste discharge in accordance with Title 23, Division 3, Chapter 9, Article 3, or the California Administrative Code not later than 180 days before this expiration date as application for reissuance of waste discharge requirements.
15. This Order shall serve as a National Pollutant Discharge Elimination System (NPDES) permit pursuant to Section 402 of the Clean Water Act or amendments thereto, and shall become effective immediately upon adoption, provided the Regional Administrator, EPA has no objection. If the Regional Administrator objects to its issuance, the permit shall not become effective until such objection is withdrawn.