Calculating your wastewater bill

 Calculating your wastewater bill

Since wastewater is a non-metered service, there is no exact way to determine how much goes down drains and toilets for individual customers. Like most utilities, we calculate projected wastewater flows by using a formula for all residential customers.

The calculation is designed to bill for water that runs down drains and toilets and excludes, as much as possible, water used outdoors.

Using Automated Meter Reading, a read is taken at the beginning and end of the winter period. To calculate the winter period average daily units (ADU), water meters are read no earlier than Dec. 1 and no later than the last day of February.

The winter ADU is determined by the usage between the December and February meter read divided by the number of days in that period. For example:

  • Dec. 1 water meter reading = 38,886 CF
  • Feb. 27 water meter reading = 40,132 CF
  • 40,132 minus 38,886 = 1,246 CF
  • Days between readings = 89 days
  • 1,246 divided by 89 = 14 ADU

Not everyone will have a winter period ADU due to moving in to a new house or apartment.