The Sonoma Valley County Sanitation District (District) completed a study aimed at giving residential customers a way to exercise control over part of their sewer bills while encouraging water conservation. This page describes the fixed billing calculation method and volume-based method that replaced it. It also gives ideas on what you can do to reduce your costs with the volume-based rate. Note that the volume-based rate structure only applies to residential accounts with connections to both water and sewer, not commercial accounts and not those residential accounts without a water account through Valley of the Moon Water District or City of Sonoma. For example a condominium unit will often not have an individual water meter account and thus would not be included in the volume-based rate structure. The excluded residential accounts will stay on the fixed rate billing structure.
The Fixed Rate Billing Calculation still applies to these types of sewer accounts:
Fixed Rate sewer bills are calculated based on usage of an Equivalent Standard Dwelling (“ESD”). An ESD is defined as what an average single family home would use in a given year. All single family homes, which constitute most of the users in the District, are charged the same flat charge based on 1 ESD, regardless of the amount of water used in a home and treated at the District. Thus, this method does not reward households who use less water and create less sewage for treatment.
The Volume-Based Rate Billing Calculation applies to these types of sewer accounts:
The residential volume-based rate structure is like a two-layered cake:
City operated sanitation districts (including the cities of Cotati, Healdsburg, Petaluma, Rohnert Park, Santa Rosa, Sebastopol and the Town of Windsor) base rates partially on an estimate of the amount of sewage generated by each household, based on water usage during winter months. The 2010 District study found that such “volume-based” rate structures better account for household sewer discharge, promote water conservation, and provide financial reliability for District services. The study also found that volume-based rates would provide District ratepayers with the opportunity to control a portion of their sewage bill.
This calculator is only for Single family Dwellings in Sonoma Valley County Sanitation District's service area, not for multi-family or commercial because the number of Equivalent Standard Dwellings vary.
The formula for this calculation is $740 + (Gallons per month entered by user) X .00599 per gallon X 12 months = Your sanitation charge per year.
To maximize savings on your sewer bill, avoid outside water use during the winter months (for example, watering lawns and gardens, washing cars and hosing down driveways) and take advantage of District rebate programs. Available rebate programs include:
For more information, please contact us.