Industrial facilities are only one of many sources of wastewater discharged into municipal sewers. There are approximately 3,350 commercial businesses in Napa. The wastewater discharged by industries or commercial facilities is often contaminated by a variety of toxic or otherwise harmful substances (for example by-products of industrial processes such as copper, lead, mercury, nickel and other heavy metals and organic pollutants) not common to other sources. These wastes can pose serious hazards. Since sewage collection and treatment systems have not been designed to treat them, industrial wastes can damage sewers and interfere with the operation of treatment plants, or pass through the systems untreated, resulting in pollution of nearby water bodies and increase the cost and environmental risks of sludge treatment and disposal.

The undesirable effects resulting from the discharge of industrial wastewater into municipal sewers can be prevented. Industrial facilities, using proven pollution control techniques, can remove pollutants from their wastewaters before discharging them into the municipal sewage treatment system. This practice is known as "pretreatment".

The General Pretreatment Regulations establish responsibilities of Federal, State, and local government, industry and the public to implement Pretreatment Standards to control pollutants from the industrial users which may pass through or interfere with Publicly Owned Treatment Works (POTW) treatment processes or which may contaminate sewage sludge.

Napa Sanitation District; a Publicly Owned Treatment Works (POTW) is required to implement and enforce its approved pretreatment program in accordance with Federal pretreatment regulations (40CFR Part 40), pretreatment standards promulgated by the Clean Water Act, and the National Pollutant Discharge Elimination System (NPDES) Order. The three objectives of the Pretreatment Program are:

1. To prevent the introduction of pollutants into the POTW which will interfere with the operation of the POTWs, including interference with its use or disposal of municipal sludge;
2. To prevent the introduction of pollutants into POTWs which will pass through the treatment works or otherwise be incompatible with such works; cause violation of effluent limitations and
3. To improve opportunities to recycle and reclaim municipal and industrial wastewaters and sludges (40 CFR 403.2).

The NPDES Order No. R2-2005-0008 requires the District to develop and implement an aggressive source control program. The District is required to implement and improve its existing Pollutant Minimization/Pollution Prevention Program. The goal of the Pollutant Minimization/Pollution Prevention Program is to eliminate or reduce discharge of all pollutants that have been found to impact or threaten beneficial uses. The Program emphasizes pollutant source reduction "upstream" of treatment plants and techniques such as material recycling, reuse and conservation, material substitution, product substitution, and process modifications. The Program also supports increased water recycling and reuse, and wastewater treatment prior to discharge to the sanitary sewer in order to reduce pollutant loadings to the treatment facility and therefore to the receiving waters.

The District's Pretreatment Program controls the amounts of pollutants that are discharged to the sanitary sewer system through active regulation of numerous industrial and commercial businesses in Napa. Program activities include periodic on-site inspections, permit writing and administration, sampling of various discharges and maintaining a list of industrial and commercial businesses.

Need more information?
Please give us a call if you would like to know more about the District's Pretreatment Program or requirements. Our staff will be more than happy to assist you.

This ordinance regulates the use of public and private sewers and drains, the installation and connection of building sewers, the installation of sewer laterals, and public sewer main extensions. It also provides the fee structure for the installation and connection of sanitary sewers, regulates the discharge of waters and wastes into the public sewer systems and provides penalties for the violations of any of these provisions. To view or download a section of the Sewer Use Ordinance, select from the following PDFs*:

	SECTION A - Definitions
	SECTION B - Sewer Use Regulations
	SECTION C - Sewer Service Charges

View or download the Napa Sanitation District Waste Discharge Permit (NPDES No. CA 0037575).

View or download the Pretreatment Program Requirements by going to our useful link: Environmental Protection Agency.