Wastewater > Pretreatment
Wastewater : Pretreatment
The City of San Luis Obispos 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 plants processes, contaminate
the sludge or pass through treatment and end up in San Luis Creek, the receiving water for
the facilitys 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 facilitys
discharge requirements and degradation of the creeks environment.
How the Program
Inspection, sampling, documentation and
public education are the basis of the Citys 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 Citys 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.
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
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.
Restaurant 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.
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 owners
responsibility to demonstrate that the waste is non-hazardous.
Aaron Floyd, Industrial Waste
Daniel Goulet, Industrial Waste Inspector, 781-7426