1. Resource optimization
Description: This measure examines resource use efficiency, including labor and material per unit of output or mile of collection/distribution system.
Example calculations:
- Customer accounts per employee: Number of accounts ÷ number of FTEs. (FTE = 2,080 hours per year of employee time equivalent.) This is a QualServe Indicator.[1]
- MGD water delivered/processed per employee: Average MGD delivered/processed ÷ FTEs per year. This is a QualServe Indicator.[2]
- Chemical use per volume delivered/processed: Amount of chemicals used ÷ MG delivered/processed during reporting period. (Alternatively can use dollar amount spent on chemicals ÷ MG delivered/processed; in this case a rolling average for amount spent would account for periodic bulk purchases.)
- Energy use per volume delivered/processed: KWH ÷ MG delivered/processed during reporting period. (Alternatively can use dollar amount spent on energy ÷ MG delivered/processed.)
- O&M cost per volume delivered/processed: Total O&M cost ÷ MG delivered/processed during reporting period.
- A utility can also apply the above resource use per volume delivered/processed calculations to resource use per mile (or 100 miles) of collection/distribution system, (i.e., chemical use per mile, energy use per mile, or O&M cost per mile).
2. Water management efficiency
Description: This measure assesses drinking water production and delivery efficiency by considering resources as they enter and exit the utility system.
Example calculations:
- Production efficiency: Ratio of raw water volume taken into the treatment system to treated water produced.
- Distribution system water loss (a.k.a. non-revenue water) (percent): 100 X [volume of water distributed – (volume of water billed + volume of unbilled authorized water) ÷ total volume of water distributed]. (Quantifies the percentage of produced water that fails to reach customers and cannot otherwise be accounted for through authorized usage.) This is a QualServe Indicator.[3]
- Meter function (percent): 100 X (total number of active billable meters minus stopped or malfunctioning meters ÷ total number of active billable meters).
More information on resources for this attribute-related measure can be found in the EUM Resource Toolbox.
[1] Part of the same Indicator (set) as MGD water delivered/MGD waste water processed per FTE. From AWWA and AwwaRF, Selection and Definition of Performance Indicators for Water and Wastewater Utilities, p. 40. 2004. Note: This material is copyrighted and any reprinting must be by permission of the American Water Works Association.
[2] Ibid., p. 40.
[3] Ibid., p. 59.