A study conducted by Union Sanitary District (USD) in 1997 focusing on wastewater discharges from commercial car washes to the sanitary sewer, found that in most cases, levels of oil & grease, copper, lead, nickel and zinc in wastewater exceeded USD discharge limits with some results exceeding California hazardous waste limits. All commercial car washes are equipped with an approved treatment system consisting of a multi-chambered interceptor that is designed to reduce the pollutant load to acceptable levels. Therefore, the District determined that the high discharge levels of these pollutants is a result of not maintaining these systems at a level where they are effective. As a result, USD has adopted the following discharge requirements for commercial car washes. These requirements cover all 24-hour coin operated, automated/manual and service station facilities located within the District's service area of Fremont, Union City and Newark:

1. All commercial car washes shall reduce the concentration and amount of pollutants in their wastewater discharge to comply with all USD discharge limits.

2. All commercial car washes shall have a professional service pump-out all chambers of their interceptors at least twice a year. Some facilities may be required to increase this frequency. Employing a septic service to perform this operation is strictly prohibited.

3. All owners of commercial car washes shall properly maintain the on-site treatment system to meet local discharge limits.

Please direct any question you may have regarding these requirements to the commercial environmental division at Union Sanitary District.