Industrial Pretreatment

What is industrial pretreatment and why do we need it?

Industrial wastewater is non-domestic wastewater originating from processes such as manufacturing, food processing plants, and mining operations. This type of wastewater may contain harmful or higher concentrations of pollutants compared to domestic sewage that could affect the quality of receiving waters or interfere with the wastewater treatment plant. For example, dairy manufacturers contain similar pollutants as domestic wastewater, but the strength of the same pollutants can be up to 20 times higher. This makes the treatment process difficult and can cause wastewater treatment plants to violate NPDES permit limits.

The EPA mandates the Industrial Pretreatment Programs to control the amount and types of non-domestic wastes that is disposed into sewer systems. This program allows CWS to protect infrastructure and employees from exposure to toxic chemicals, as well as the environment and public from pass through of pollutants to the Ashley River. Charleston Water System complies with the Industrial Wastewater Program through their grease trap program, education outreach to targeted sewer customers, permitting users to control waste streams, and monitoring compliance of users.

Any request for information regarding the ability to use the sewer for specific types of waste, interest in discharging temporarily to CWS system, or interest in setting up disposal accounts for waste haulers should be directed to