Attribute Related Measures: Product Quality

1. Product quality regulatory compliance

Description: Water product quality compliance, particularly with regards to 40 CFR Part 141 (the National Primary Drinking Water Regulations), the National Pollutant Discharge Elimination System, and any other relevant federal (Clean Water Act, Safe Drinking Water Act, etc.) or state statute/regulations and permit requirements. The scope can include the quality of all related products, including drinking water, fire suppression water, treated effluent, reused water, and biosolids, as well as quality-related operating requirements such as pressure and number of sewer overflows.

Example calculations:

  • Drinking water compliance rate (percent): 100 X (number of days in full compliance for the year ÷ 365 days). This is a QualServe Indicator. [1]
  • Wastewater treatment effectiveness rate (percent): 100 X (365 – total number of stan­dard noncompliance days ÷ 365 days). This is a QualServe Indicator.[2]
  • Number, type, and frequency of “near (compliance) misses”: For example, reaching 80-95% of allowable levels of “X” during reporting period, typically per month. Tracking this type of measure could be used to improve performance in these “near miss” areas before violations occur.

2. Product quality service delivery

Description: This measure assesses delivery of product quality service based on utility-established objectives and service level targets. It focuses on non-regulatory perfor­mance targets.

Example calculations:

  • Drinking water flow and pressure (percent): 100 X [number of customers with less than (flow of “X” gallons per minute (gpm) and pressure of “Y” pounds per square inch (psi)—levels set by utility) ÷ total number of customers] (during re­porting period, typically per month).
  • Fire suppression water flow and pressure (percent): 100 X [hours of time when (flow of “X” gpm and pressure of “Y” psi—levels set by utility) is available for fire sup­pression at maximum day demand ÷ total number of hours when fire suppres­sion water should be available at maximum day demand] (during reporting pe­riod, typically per month).
  • Service interruptions (percent): 100 X (number of active account customers experi­encing a service interruption of greater than 1 hour ÷ total number of customers during reporting period) (typically per month). Note: the utility may elect to measure planned and unplanned interruptions separately.
  • Water quality goals met/not met: Number of days in reporting period (typically one month) where utility-defined beyond-compliance targets are met/not met.
  • Sewer backups (if not included in permit requirements) (amount and percent): Number of customers experiencing backups each year; 100 X (number of custom­ers experiencing backups each year ÷ total number of customers).
  • Sewer overflows (if not included in permit requirements): Number of sewer over­flows per 100 miles of collection system piping.
  • Water reuse (amount and percent):
    • Amount: Amount of water supplied that is from reused/recycled sources.
    • Percent: 100 X (amount of water supplied that is from reused/recycled water ÷ total amount of water supplied).

Then, as desired, these amounts can be broken into recipients/applications (e.g., irrigation, agriculture, industrial processes, etc.).

  • Biosolids put to beneficial use (percent): 100 X (amount of biosolids produced that are put to a beneficial use ÷ total amount of biosolids produced) (in wet tons per year).

More information on resources for this attribute-related measure can be found in the EUM Resource Toolbox.

[1] This is one of the 22 Performance Indicators from the Qualserve program, a voluntary quality improvement program designed for water and wastewater utilities by the American Water Works Association and the Water Environment Federation. Reference from the American Water Works Association and the AWWA Research Foundation, Selection and Definition of Performance Indica­tors for Water and Wastewater Utilities, p. 57. 2004. Note: This material is copyrighted and any reprinting must be by permission of the American Water Works Association.[2] Ibid., p. 71.