Since 1974, the U.S. EPA has set national safety standards for over 80 contaminants that may be found in drinking water.
Once the EPA develops a new standard, the rule is sent to the states. States adopt and build upon drinking water standards based on their own laws and rules. In Arizona, the EPA has granted ADEQ the right and responsibility to oversee drinking water rules and programs.
While ADEQ adopts, builds upon, and enforces drinking water standards, local governments and private water suppliers are responsible for the quality of the water that flows to your tap. Water systems test and treat their water, maintain the distribution systems that deliver the water, and report on their water quality to the state. ADEQ provides technical assistance to water suppliers and can take legal action against systems that fail to provide water that meets these standards.
Current Drinking Water Rules
Arizona's drinking water rules are located in Title 18, Chapter 4, of the Arizona Administrative Code (18 A.A.C. 4). ADEQ adopted the federal rules in order to maintain Arizona's primary enforcement authority of the Safe Drinking Water Act. The impetus for the rulemaking is to maintain Arizona's primary enforcement authority of the Safe Drinking Water Act, pursuant to A.R.S. §49-353(A)(2)(a), which requires ADEQ to create rules that implement the federal safe drinking water program.
The notice of final rulemaking is made available by the Arizona Secretary of State - Arizona Administrative Register (AAR)
ADEQ's unofficial version of 18 A.A.C. 4, combining the final state rules with the federal rules may be found at: