Sanitary sewer billing calculations

Sewer bills are calculated using the water usage of the address being billed as this is the driver for the City’s sewer treatment costs The City attempts to make allowances for water that is used to water vegetation during the non-winter months and therefore is not discharged into the sewer system. This leads to what is known as the sewer “cap.” The sewer cap creates a limit for water usage that will be used to calculate sewer usage. The following details the standard method and the ‘capped’ method for bill calculation.

Standard Residential Method (Winter months)

During the winter months (December through March), customers’ residential bills will be based on the volume that is equal to the metered water consumption on the same bill.

Example: Water usage for the Dec. 1 bill was 8,000 gallons. This usage will be used to calculate the sewer bill as follows:


Variable rate = 8,000 gal x 4.09 per 1,000 gal =


Fixed rate = $15.93 per month =


Wastewater Capital Investment Fee = 8,000 gal x $3.73 per 1,000 gal =


Total sewer portion of utility bill =



‘Capped’ Residential Method (Non-Winter Months)

Sewer service charges for bills issued the remaining eight months of the year (April through November) shall reflect a charge for sewer volume equal to the lowest of:

  • The actual water metered for the same period (the method used above); OR
  • One and two-tenths (1.2) times the average water consumption for the lowest three (3) of the four bills issued December through March. An exception will be made if the actual consumption in any of those months is lower than 2,000 gallons, then 2,000 gallons will be used in computing the average. In the case of a new resident where no average for the customer is available, the average will be assumed to be 7,000 gallons.

Example: December billed consumption 8,000 gal; January billed consumption 12,000 gal; February billed consumption 30,000 gal, March billed consumption 10,000 gal.

  • 30,000 is thrown out, since it is the highest of the 4 ‘non-capped’ months’ usage 
  • 8,000+10,000+12,000 = 30,000 / 3 = 10,000 gallon average ‘non-capped’ usage 
  • 10,000 x 1.2 = 12,000 gal is the sewer usage maximum for ‘capped’ months 

Once the maximum usage is determined, then the sewer bills will be calculated in the same manner as the Standard Residential Method above. The only difference being that the bill will be calculated using the lesser of the actual water usage or the previously determined maximum usage.

Non-Residential Method

Sanitary sewer service charges for all customers other than residential accounts shall be based on a volume equal to the metered water consumption reflected on the same bill, unless there is installed, at the customer’s expense, a meter for measuring the actual sewer volume discharged into the sanitary sewer system.