Publicly owned treatment works (POTWs) collect wastewater from homes, commercial buildings and industrial facilities and transport the waste via a series of pipes, the collection system, to a wastewater treatment plant. At the treatment plant harmful organisms and other contaminants are removed from the wastewater prior to release into the receiving body of water.
As a general rule, POTWs are designed to treat domestic wastes only (typical household wastes and biodegradable commercial and industrial wastes). These pollutants are coined "conventional" pollutants. Commercial and industrial facilities may discharge toxic pollutants as well.
The discharge of toxic pollutants may harm the POTW, impair the surrounding environment, endanger POTW workers and also prevent the reuse of the treatment plant's byproducts. Thus, wastewater with such pollutants typically has to be treated prior to release to the POTW. Treating wastewater prior to discharge to a POTW is the definition of pretreatment.
The National Pretreatment Program, published in Title 40 Code of Federal Regulations (CFR) Part 403 provides the regulatory basis to require non-domestic dischargers to comply with standards to ensure that the goals of the Clean Water Act are attained.
The Town of Amherst's Industrial Pretreatment group works to uphold the standards as set in 40 CFR 403 as well as the local standards as regulated by the Town of Amherst's Local Sewer Use Law (Chapter 160 of the Code of the Town of Amherst). | 
