Sewer Submeter Program

Client Assistance Memo 1102

The sewer submeter program was instituted in the late 1950’s to make allowances for commercial customers who use water that does not enter the sanitary sewer. Water used for irrigation, delivery of water to ships, and water used in manufactured goods or products are all examples of situations where a submeter may prove beneficial.

Regulation of Submeters

The primary authority for sewer submeters is contained within the January 1961 Agreement for Sewage Disposal between King County and the City of Seattle. Seattle Municipal Code 21.28.090 directs Seattle Public Utilities (SPU) to calculate commercial sewer based on water that should go down the sewer. There is a provision for commercial customer owned submeters that measure water used exclusively for irrigation, delivery of water to ships, evaporation and water used in manufactured goods and commodities. There is no provision in the SMC for residential submeters. Residential properties are billed sewer under the sewer max program in order to compensate for irrigation.

Types of Submeters

  • A submeter is commonly defined as either a deductible meter or a chargeable meter. The submeters are physically the same but differ in their installation and billing method.
  • A deductible meter is installed on the water line that supplies the allowable deduction and is read by SPU with the registered consumption subtracted from the customer’s sewer charges. In this type of installation, sewer is billed on all water used except for that measured through the submeter.
  • A chargeable meter is installed on a water line supplying a portion of the facility that does discharge to the sewer. This meter is also read by SPU with the registered consumption used as the basis for sewer charges.

Note: Certain types of equipment, including cooling towers, swimming and wading pools, require the installation of both a deductible and a chargeable meter. In these cases, a deductible meter will deduct water supplied to equipment from their sewer charges, while the chargeable meter will capture the percentage of water that is actually discharged to the sewer.

Submeter Fees

  • All new or replacement submeters, meter registers or encoder receiver transmitter will pay a fee comprised of inspection costs, billing system set up costs, and plan review costs. See SPU Standard Charges (pdf).

Property Owner Responsibilities

  • Provide SPU with a completed Sewer Submeter Application & Inventory Form (pdf).
  • Submit a simple drawing of the property, showing on-property water lines, the location of the water meter that serves the submeter(s) and all existing and proposed submeter(s).
  • Purchase and install submeters after SPU review and approval.
  • Maintain and test submeters regularly to ensure accurate operation.
  • Locate all submeters in an area that is safe and easily accessible for meter readers and that is approved by SPU prior to installation.
  • Confirm that your submeters register in CCFs.
  • Contact our Submeter Program office at (206) 256-5500 for a physical inspection of your meter after installation.
  • Meet current SPU Automated Meter Reading (AMR) technology requirements for all submeter installations, regardless of the physical location of the meter. Sewer submeter technology requirements (pdf).
  • Pay all SPU Standard Charges (pdf).
  • Notify SPU upon change of use or change of occupancy.

SPU Responsibilities

  • Inspect all submeter installations to ensure they are for an approved deduction or required charge prior to acceptance into the SPU billing system.
  • Verify that the meter installed by the customer meets all criteria required by SPU meter readers and the SPU billing system.
  • Read all submeters on a monthly or bi-monthly frequency depending on account specifications.
  • Respond to all customer requests for submeter information, inspections, problem-solving and other submeter services in a timely manner.
  • Offer customers in like circumstances the same requirements, services, contracts, agreements or privileges.

Reduce Delays

  • Don’t assume that simply installing a submeter guarantees acceptance by SPU. Always contact SPU prior to installing a submeter so we may review your design and help you ensure accurate metering and billing of sewer charges.
  • Changes to your submeter design after review by SPU may cause your submeter application to be rejected. Always contact your SPU representative if you have any changes to or questions on your design.


  • To schedule a property visit, call (206) 256-5500.

Useful Links

Seattle Public Utilities (SPU) supplies water to 1.3 million people in the region. Nearly all this water is from the 90,000-acre Cedar River Watershed and the 13,300-acre South Fork Tolt River Watershed in eastern King County. Our goal is to provide a reliable source of high quality drinking water, while protecting the environmental resources of our watersheds.

Legal Disclaimer

This Client Assistance Memo (CAM) should not be used as a substitute for codes and regulations. The applicant is responsible for compliance with all code and rule requirements, whether or not described in this CAM.