1. A. Definitions. The following definitions apply for purposes of this Article:

   1. 1. “Annual operation costs” means the mean annual average baseline monitoring assistance program operation costs of the three preceding calendar years.

   2. 2. “Baseline monitoring” means initial, routine, and reduced monitoring for contaminants included in the monitoring assistance program, which, at a minimum, include those categories of contaminants listed in A.R.S. § 49-360(A)(1) through (A)(4), which are:

      1. a. Volatile organic chemicals,
      2. b. Synthetic organic chemicals,
      3. c. Inorganic chemicals except for copper and lead,

      4. d. Radiochemicals.

         Baseline monitoring does not include the quarterly monitoring required for the life of the system as a condition of treatment approval under Title 18, Chapter 5, Article 5.

   3. 3. “Compliance period” means a full calendar year.
   4. 4. “Triggered monitoring” means increased monitoring required by this Chapter when the results of baseline monitoring indicate the presence of a contaminant at a level that requires increased monitoring by a participating public water system. Triggered monitoring does not include quarterly monitoring required for the life of a system as a condition of treatment approval under Title 18, Chapter 5, Article 5.
   5. 5. “Triggered monitoring assistance program” means the subpart of the monitoring assistance program that allows the Department to conduct triggered monitoring for those public water systems that are already participating in the monitoring assistance program for baseline monitoring.
2. B. Mandatory baseline monitoring participation. Except as allowed by subsection (D), a community or non-transient, non-community public water system that serves 10,000 or fewer persons shall participate in the monitoring assistance program for baseline monitoring. Within 60 days after receiving notice of participation in the monitoring assistance program from the Department, a public water system that determines that it serves more than 10,000 persons shall substantiate its determination by submitting evidence-based documentation to the Department.

3. C. Voluntary baseline monitoring participation. A public water system that is not obligated to participate in the baseline monitoring assistance program may elect to participate in the baseline monitoring assistance program subject to subsections (1) through (3). Upon payment of the required fees, the public water system’s participation shall begin at the start of the next full calendar year of a compliance period.

   1. 1. The owner of the public water system must:

      1. a. Request permission from the Department to participate in the baseline monitoring assistance program, on a form provided by the Department,
      2. b. Agree to participate in the baseline monitoring assistance program for a minimum of three years,
      3. c. Pay the fees required by R18-4-304,
      4. d. Provide information regarding the number of service connections and entry points to the distribution system, and
      5. e. Agree to MAP programmatic procedures, such as agreeing to allow the contractor on-site and timely payment of fees; and
   2. 2. The Department determines, in its discretion, that the system is likely not a financial or administrative burden to the program, thereby approving the system for participation in MAP.
   3. 3. However, if a voluntary MAP participant poses a financial or administrative burden to the program, as determined by the Department, the Department may deny or revoke approval to participate. For existing participants, revocation is effective upon the start of the calendar quarter following the Department’s written notification to the system. The system may participate in MAP at a later date, subject to a new participation request and Department approval pursuant to this subsection.

4. D. Monitoring Assistance Program Opt-out Applicability and Procedures for Department of Defense Public Water Systems.

   1. 1. Public water systems owned and operated by the U.S. Department of Defense (DoD) may conditionally opt out of the Monitoring Assistance Program in a form and manner prescribed by ADEQ.
   2. 2. A DoD owned and operated facility that meets Monitoring Assistance Program applicability thresholds in A.R.S. § 49-360 and has previously opted out of the program may opt in to the program at any time.
   3. 3. Notwithstanding subsection (D)(1), ADEQ may require a DoD public water system to participate in the Monitoring Assistance Program if the Department determines that the DoD public water system has compliance deficiencies that pose a significant risk to any person, the public health, safety, or welfare, or the environment. ADEQ may require a DoD public water system to become a participant of the Monitoring Assistance Program either temporarily or indefinitely, based upon the gravity of the deficiency or deficiencies and upon the deviation of the deficiency or deficiencies from required standards.

Historical Note

Adopted effective April 28, 1995 (Supp. 95-2). Amended by final rulemaking at 8 A.A.R. 3046, effective May 1, 2002 (Supp. 02-3). Section R18-4-301 repealed; new Section renumbered from R18-4-224 and amended by final rulemaking at 14 A.A.R. 2978, effective August 30, 2008 (Supp. 08-3). Amended by final rulemaking at 31 A.A.R. 4179 (October 31, 2025), effective December 7, 2025 (Supp. 25-4).