Drinking Water Rules Overview
Since 1974, U.S. EPA has set national safety standards for over 80 contaminants that may be found in drinking water (there are currently 87 primary contaminants and 15 secondary contaminants). U.S. EPA publishes a Contaminant Candidate List (CCL) with drinking water contaminants they are studying. The goal is to determine whether these contaminants present enough of a risk to human beings that health standards need to be set for them. Sometimes U.S. EPA feels a contaminant does not pose a significant risk to human health. In this case, no standard is set for it.
If it is determined that there is a risk to human health, U.S. EPA will develop a drinking water standard. This standard will be based primarily on health protection, but may include an assessment of available detection methods, current treatment and remediation techniques and an analysis of costs vs. benefits.
Once U.S. 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, ADEQ has primacy for drinking water rules and programs. This means U.S. EPA has granted ADEQ the right and responsibility to oversee this program. Under the ADEQ Primacy agreement, federal drinking water rules are incorporated into the Arizona Administrative Code where they then become enforceable by the state.
While ADEQ adopts, builds upon, and enforces drinking water standards, local governments and private water suppliers have direct responsibility for the quality of the water that flows to your tap. Water systems test and treat their water, maintain the distribution systems that deliver water to consumers, 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 Rulemaking Summary
Arizona's drinking water rules are located in Title 18, Chapter 4, of the Arizona Administrative Code (18 A.A.C. 4). The Department has been working with stakeholders on a major revision of 18 A.A.C. 4 for the past few years. 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 states that ADEQ shall develop rules that meet "[t]he requirements established by the United States environmental protection agency for state primary enforcement responsibility of the safe drinking water act, including the requirements of 40 Code of Federal Regulations parts 141 and 142."
In this rulemaking, many of the current rules will be repealed, and the National Primary Drinking Water Regulations (40 CRF Part 141) will be incorporated by reference. The rulemaking restructures the state's current drinking water rules by incorporating the federal rules by reference, thereby updating the state drinking water regulations so that they are as stringent as the federal rules rather than restating the federal regulations. This will reduce the potential for conflict between state and federal law and ensure Arizona retains jurisdiction to implement the Safe Drinking Water Act. Utilization of incorporation by reference will also facilitate review and approval of Arizona's rules by applicable state and federal entities.
The final rulemaking restructures Chapter 4 as follows:
Article 1, NPDWRs;
Article 2, State Drinking Water Regulations (state rules with no federal equivalent);
Article 3, Monitoring Assistance Program;
Article 4, Repealed;
Article 5, Recodified;
Article 6, Capacity Development Requirements for a New Public Drinking Water System;
Article 7, Repealed; and
Article 8, Technical Assistance
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 being incorporated by reference: