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Wastewater : Pretreatment
Pipes releasing water into fish habitat.

The City of San Luis Obispo’s Pretreatment Program was established in 1983 to provide protection to the water reclamation facility (WRF) and the sewer collection system by controlling the introduction of non-domestic pollutants to the WFR and system. This program uses the Federal General Pretreatment Regulations (40 CFR 403) to enforce general discharge prohibitions and categorical standards. The City was required by the state to establish the program to protect the WRF from non-domestic wastes that may upset or inhibit the plant’s processes, contaminate the sludge or pass through treatment and end up in San Luis Creek, the receiving water for the facility’s effluent discharge. An upset or inhibition in the facility can mean reduced treatment of wastes, contaminated sludge that can result in expensive handling and disposal costs and pass-through which may result in a violation of the facility’s discharge requirements and degradation of the creek’s environment.

How the Program Works

Inspection, sampling, documentation and public education are the basis of the City’s program. Inspection and sampling ensure that pollutants and wastes are being discharged and/or handled by the commercial or industrial user (IU) in compliance with the City’s sewer use ordinance. Documentation gives the City a hard copy of sampling, inspections and any other event that may have occurred. Public education offers the City the opportunity to give the public and industry an overview of the pretreatment program, provide assistance in program compliance and answer questions.

All permitted industries get inspected. Permitted industries include, but are not limited to; electroplaters, restaurants, automotive repair shops, photofinishers, laundries, carwashes, dry cleaners, radiator shops, etc. Depending on the permit issued, a facility may be inspected up to 4 times a year.

Program Funding
The program receives about 35% of its revenues from industrial users fees while the other 65% comes from the sewer fund. Industrial users fees are classified into three classes; Significant industrial users-$685.00, Class I industrial Users-$210.00 and Class II industrial users-$65.00. Users may determine their classification by looking at their permit number. I or II follows the permit number, significant permits state such on the permit. The fees are annual, but the City Finance Department divides the bill into bi-monthly invoices.

Facility Classification
All facilities are evaluated by the information provided on the commercial users survey application and inspection before being classified. Facilities are classified as significant industrial user if they fall under the federal definition of a significant or categorical industry. Currently the City permits about 5 such facilities.

Class I industrial users are defined as facilities that have materials or wastes on site that if discharged to the sewer may impact City facilities in a negative manner. These wastes include, but are not limited to; hazardous wastes and materials, pH, and other non-conventional pollutants. Facilities that may discharge conventional pollutants, such as grease of animal or vegetable origin, non-hazardous solids, or laundry discharges are classified as Class II users. Conventional pollutants are pollutants usually found in domestic discharges, characteristic of the sewer discharge from a regular household.

  Class II Permit: Restaurants discharge oil and grease in quantities greater than a normal household.

Automotive Repair  Class I Permit: These facilities generate hazardous wastes which if discharged to the sewer may cause considerable damage to the collection system and treatment process.

Dry Cleaner  Class I Permit: Dry cleaners generate hazardous waste and may release small quantities of solvents to the sewer.

Electroplating Shop  Significant Permit: Electroplaters fall under the federal definition of a significant industrial user, generate hazardous waste and discharge non conventional pollutants to the sewer.

Car Wash/Automotive Detail  Class I or Class II Permit: Car Washes primarily discharge conventional pollutants to the sewer, but if engines are being pressure washed the oil and grease from the washing may be hazardous. It is the owner’s responsibility to demonstrate that the waste is non-hazardous.

Program Staff

Aaron Floyd, Industrial Waste Coordinator, 781-7425
Daniel Goulet, Industrial Waste Inspector, 781-7426

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