1. (1) Owners of water supply systems serving the public (purveyors) in the Delaware River Basin that distribute water supplies in excess of an average of 100,000 gallons per day (gpd) during any 30-day period shall develop and undertake a systematic program to monitor and control leakage within their water supply system. Such a program shall at a minimum include: periodic surveys to monitor leakage, enumerate non-revenue water (or in instances where AWWA methodology as set forth in section 890.8 of this Part has not yet been adopted, enumerate unaccounted-for water), and determine the current status of system infrastructure; recommendations to monitor and control leakage; and a schedule for the implementation of such recommendations. Each purveyor's program shall be subject to review and approval by the designated agency in the state where the system is located.
2. (2) Non-revenue water is defined by AWWA as the sum of unbilled authorized consumption, apparent losses and real losses. Non-revenue water percent is defined as non-revenue water divided by the amount of water entering the distribution system times 100 percent.
3. (3) Unaccounted-for water is defined as the amount of water entering the distribution system minus the amount of water delivered through service meters. Unaccounted-for water percent is defined as unaccounted-for water divided by the amount of water entering the distribution system times 100 percent.
4. (4) The designated State agencies are: Delaware Department of Natural Resources and Environmental Control; New Jersey Department of Environmental Protection; New York Department of Health; and Pennsylvania Department of Environmental Protection.

5. (b) Each purveyor shall strive to minimize system leakage to levels as guided by IWA/AWWA Water Audit Methodology (AWWA Water Loss Control Committee [WLCC] Water Audit Software) and corresponding AWWA guidance.

   After a purveyor has submitted to the appropriate designated agency its initial program to monitor and control leakage, the purveyor shall prepare and submit a revised and updated program every three years thereafter or at such greater frequency as may be required by the designated State agency. The designated State agency may require more frequent program submission from purveyors with unaccounted-for or non-revenue water that is in excess of 15 percent.

6. (c) Any project approvals hereafter granted pursuant to section 3.8 of the DRBC compact or any renewal of a project approval shall be subject to the provisions of this regulation.

(a)