PSC 185.85(1) (1) Definitions. In this section:

PSC 185.85(1)(a) (a) “Apparent loss” means the volume of water attributable to customer and station meter inaccuracies, billing and data transfer errors, unauthorized consumption, and theft.

PSC 185.85(1)(b) (b) “Authorized consumption” means the volume of water used by metered and unmetered customers and the volume of water used for other purposes that is implicitly or explicitly authorized by the utility, including water used for flushing water mains and sewers, fire protection and training, street cleaning, public fountains, freeze prevention, and other municipal purposes regardless of whether the use is metered.

PSC 185.85(1)(c) (c) “Non-revenue water” means the volume of water equal to the difference between the volume of water entering the distribution system and the volume of water that is sold.

PSC 185.85(1)(d) (d) “Real loss” means the volume of water attributable to leaks and losses in the pressurized distribution system up to the customer meter, including water lost due to main breaks, service breaks, and tank and reservoir overflows.

PSC 185.85(1)(e) (e) “Revenue water” means the volume of water entering the distribution system that is billed and for which the utility receives revenue.

PSC 185.85(1)(f) (f) “Unaccounted-for water” means the volume of water entering the distribution system for which a specific use or purpose cannot be determined.

PSC 185.85(1)(g) (g) “Water loss” means the difference between the volume of water entering the distribution system and authorized consumption.

PSC 185.85 Note Note: Water loss equals the sum of real and apparent losses that are caused by unauthorized consumption, meter inaccuracies, accounting errors, data processing errors, leaks in transmission and distribution mains, leaks in service connections up to the customer meter, seepage, overflow, evaporation, theft, malfunctioning distribution system controls, and other unaccounted-for water, as described in the American Water Works Association M36 manual – Water Audits and Water Loss Control Programs.

PSC 185.85(2) (2) Utility practices. A public utility shall do all of the following:

PSC 185.85(2)(a) (a) Meter all water uses and sales, where practicable.

PSC 185.85(2)(b) (b) Maintain and verify the accuracy of customer meters.

PSC 185.85(2)(c) (c) Maintain and verify the accuracy of station meters.

PSC 185.85(2)(d) (d) Identify and repair leaks in its distribution system to the extent that it is reasonable for the public utility to do so.

PSC 185.85(2)(e) (e) Control water usage from hydrants.

PSC 185.85(2)(f) (f) Maintain a continuing record of system pumpage and metered consumption.

PSC 185.85(2)(g) (g) Conduct an annual water audit under sub. (3).

PSC 185.85(3) (3) Water audits.

PSC 185.85(3)(a) (a) A public utility shall conduct an annual water audit on a calendar year basis and submit the results of the audit to the commission no later than April 1 of the subsequent year.

PSC 185.85(3)(b) (b) A public utility water audit shall include the measured or estimated volume of all of the following:

PSC 185.85(3)(b)1. 1. Water purchased or pumped from all sources.

PSC 185.85(3)(b)2. 2. Water used in treatment or production processes.

PSC 185.85(3)(b)3. 3. Water entering the distribution system.

PSC 185.85(3)(b)4. 4. Water sold, including both metered and unmetered sales.

PSC 185.85(3)(b)5. 5. Water not sold but used for utility-authorized purposes, including flushing mains, fire protection, freeze prevention, and other authorized system uses.

PSC 185.85(3)(b)6. 6. Water loss.

PSC 185.85(3)(b)7. 7. Unknown or unaccounted-for water.

PSC 185.85(3)(c) (c) The components of a water audit are shown in Table 1.

Table 1. Water Audit Components