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Pretreatment Program

A Water QuALITY division FOCUS


 The Pretreatment Program is an EPA-mandated regulatory compliance focus of the Water Quality Division. The Pretreatment Program requires the City to regulate the wastewater and other discharges from industry and other non-domestic sources into the City’s Publicly Owned Treatment Works (POTW), thereby reducing the amount of pollutants released into the environment. The purpose of the program is to:

  • Prevent the introduction of pollutants from industrial and other non-domestic sources into the POTW that would interfere with its operation and treatment processes, including reduced treatment efficiencies;
  • Protect the City’s POTW from the introduction of pollutants from industrial and other non-domestic sources that cause Interference with POTW treatment processes;
  • Protect the City’s POTW from the introduction of pollutants that Pass Through the POTW treatment works untreated that could degrade the receiving waters;
  • Protect the future use and disposal of wastewater biosolids from contamination;
  • Protect both POTW personnel who may be affected by wastewater or biosolids in the course of their employment and the general public;
  • To promote reuse and recycling of reclaimed wastewater and biosolids from the POTW;
  • To provide for and promote general health, safety, and welfare of the citizens of the City;
  • To enable the City to comply with National Pollutant Discharge Elimination System Permit conditions, and any other federal or State laws to which the City is subject.

The History:

President Nixon declared his intention to establish and enforce environmental protection standards creating the Environmental Protection Agency

(EPA), in 1970. In 1972, Congress passed the "Federal Water Pollution Control Act" with the purpose to restore and maintain the quality of our nation's water. It was amended in 1977 and re-titled the "Clean Water Act." As amended, the Clean Water Act includes requirements for industries and municipalities to control their discharge into "waters of the United States" under the National Pollutant Discharge Elimination System (NPDES) Permit Program.

In 1978, the EPA established the "General Pretreatment Program Regulations" within the NPDES Program. The General Pretreatment Regulations are published in Title 40, Part 403 of the Code of Federal Regulation

(40 CFR 403). These regulations and the subsequent amendments require most Publicly Owned Treatment Works (POTW) nationwide to establish and enforce environmental protection standards for non-domestic discharge of pollutants locally.

In 1979, the City entered into a Joint Exercise of Powers Agreement (JEPA) with the cities of Glendale, Mesa, Phoenix and Tempe to create the Sub-Regional Operating Group

(SROG) for a jointly used wastewater collect and treatment facility. The SROG cities discharging from the 91st Avenue Treatment Plant located in Phoenix were required to develop Pretreatment Programs as a condition of the NPDES permit held by Phoenix. The JEPA requires each SROG city to be individually responsible and liable for the performance of all pretreatment requirements contained in 40 CFR 403.


The Program:

The Pretreatment Program regulates non-domestic discharge of pollutants subject to Pretreatment Standards. Specific types of processes are regulated by federal Categorical Standards. The Categorical Standards specify the quantity or concentration of pollutants, or pollutant property, which may be discharged to a POTW by an industry in specific industrial categories. All non-domestic dischargers are also regulated by Local Limit Pretreatment Standards that are specific for the POTW and the receiving stream. The Scottsdale Revised Code Chapter 49

is the legal authority for implementation and enforcement of all Pretreatment Standards and Requirements for non-domestic discharge to the POTW of the City and SROG.