Drinking Water

The Drinking Water Program is part of the Water and Waste Management Division of the Environmental Services Department of Maricopa County and is responsible for regulating Public Water Systems (PWSs) that operate within Maricopa County to assure that the water provided by the PWS meets or exceeds the requirements set forth in the Safe Drinking Water Act. A PWS is defined as any water system with at least fifteen service connections or regularly serves an average of at least twenty-five persons daily for at least sixty days a year. 

Drinking water rule requirements are written by the United States Environmental Protection Agency (EPA). These rules are then approved by the State of Arizona and put into the administrative code. Generally the Safe Drinking Water Act is a "self-monitoring" program to be implemented by each Public Water System. Public Water Systems are responsible for reliable water system operation and maintenance, compliance monitoring and reporting for regulated contaminants, and costs associated with water quality analyses.

Environmental Services Department maintains enforcement authority for the Safe Drinking Water Act rules and regulation established and enforced by the United States Environmental Protection Agency (US EPA) through a delegation agreement with the Arizona Department of Environmental Quality (ADEQ) for Public Water Systems* (PWS’s) operating inside Maricopa County. This authority allows the department’s Drinking Water Program to perform the following functions that enhance public health and ensure safe drinking water supplies throughout the county:

  • Maintain all Public Water System (PWS) information and inventory data
  • Review of PWS requirements to Monitor and Report water quality tests
  • Authorize reductions in routine monitoring requirements
  • Approval of new PWSs and issuance of new PWS identification numbers
  • Review water quality and approve the development of new drinking water sources
  • Review and approval of Backflow Prevention, Site Sampling, and Emergency Operations plans
  • Ensure PWS compliance with operation and maintenance requirements through routine inspections
  • Inspect drinking water treatment facilities in operation to remove or reduce specific contaminants from ground water sources or to provide treatment of surface water sources
  • Verify that a water system operator is at the correct certification for the type of PWS that is being operated
  • Conduct compliance status reviews on PWS
  • Enforce public notification requirements of PWS's
  • Submission of a monthly report to ADEQ
  • Submit compliance status reports when requested by other regulatory agencies

In addition to the above activities, Drinking Water Program staff routinely offer outreach, instruction, and advice on compliance with drinking water rules to Public Water Systems. Additionally, staff responds to citizens' complaints and initiates enforcement action whenever water system violations are found to be serious or repeated. Enforcement priority is determined by the extent of the threat posed to the public's health and/or to the environment. 

*A Public Water Systems (PWS) is defined as any water system with at least fifteen service connections or regularly serves an average of at least twenty-five persons daily for at least sixty days a year. Public water systems operating in Maricopa County are responsible for reliable water system operation and maintenance, compliance monitoring and reporting for regulated contaminants, and costs associated with water quality analyses.