Publicly Owned Water Treatment Works (POWTs, US)


By Michael J. Lynch, University of South Florida, FL
Publicly Owned Water Treatment Works (POTW) is the official term used in the US to identify a sewage treatment plant that is owned by a government agency. These facilities treat both domestic sewage created by households and industrial sewage and waste waters. In the US, these facilities are often owned by a local government. POTWs are regulated under the Clean Water Act (see entry in this dictionary, C W A). Rules related to the National Pollution Discharge Elimination System (NPDES) also apply. A POTW must obtain a permit from the US EPA.

In an effort to control waste water emissions, Clean Water Act rules related to POWTs allow the US EPA to establish a loan program for construction of POTWs. Industrial waste water emitters can avoid the need to obtain an emission permit from the EPA when industrial waste water is emitted into a POWT, though certain restrictions to this exemption apply.

There are more than 16,250 POTWs in the US. POTWs serve about 75% of the US population.

From 2005-2009, the US EPA conducted a study of POTW water to determine the effectiveness of POTWs in removing hazardous chemical from sewage water. Those studies focused on examining the presence of Contaminants of Emerging Concern (CECs) in POTW treated water. CECs include the following general categories of chemicals: (1) Pharmaceuticals and personal care products (PPCPs). These are a concern because discharge of these chemical into POTW facilities through hosuehald waste water. (2) Steroids and hormones; (3) Alkylphenols and Alkylphenol Ethoxylates (APEs), which are usually present in detergents; (4) Bisphenol A (BPA); (5) Polybrominated Diphenyl Ethers (PBDEs), common industrial ingredients in many products; and (6) pesticides. Part of the focus of that study was to determine the effectiveness of POTW treatment of waste waters, and the EPA tested chemical contaminants in water received by each facility (influent) and chemical contaminants in water emitted (effluents) by each facility. The chart below shows the results from these studies. Overall, the study indicates that POTW sewage treatment is effective for removing some, but not all hazardous waste from sewage.

Chemical Class # Tested # Influent # Effluent
PPCP 77 44 23
Steroid/Hormone 27 25 10
APE/BHA 5 4 2
PBDE 8 8 8
Pesticide 62 37 18

Created with the HTML Table Generator

For access to the complete study click HERE.

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