Septic to Sewer

The purpose of Olympia's Wastewater Utility is to protect public and environmental health by ensuring that wastewater is collected and conveyed to treatment and disposal facilities with minimal risk.

With the exception of properties served by septic systems, also known as Onsite Sewage Systems (OSS), the Utility performs the collection of all wastewater within the Olympia urban growth area.

The Olympia City Council made septic systems a key policy issue of the current Wastewater Management Plan. For the protection of public and environmental health and to meet zoning densities, the Plan significantly limited the use of septic systems for development within the city limits and recommended establishing a program to gradually promote the conversion of properties from septic systems to the sanitary sewer.


There are more than 2,000 septic systems within the Olympia City limits and an additional 2,200 septic systems are located within the City's urban growth area. Even at low to moderate housing densities, unfavorable soil conditions combined with shallow groundwater levels, challenge development served by septic systems.

Water quality problems associated with septic systems in our region are well documented. Even properly functioning septic systems still discharge only partially treated wastewater to the environment. Under the authority of the Clean Water Act, the State of Washington has listed several Olympia streams as impaired by bacteria and the State is developing recovery plans. Failing septic systems are also a principal cause of shellfish harvesting restrictions in Henderson Inlet.

Septic to Sewer Program

The Olympia City Council approved revisions to the municipal code establishing the Septic to Sewer program (effective August 17, 2009). The voluntary program provides incentives for residential connection of septic systems to sanitary sewer as well as cost recovery mechanisms for the City to make sewer extension projects possible.

If you currently have a septic system and you are interested in connecting to the sewer system, the City will waive the sewer general facility charge if you make the connection within two years of notification of the sewers's availability. The City will notify property owners by mail when the sewer becomes available and when the GFC waiver will expire for their property. If you know that the sewer is currently available to your property, there is no need to wait for notice from the City to benefit from the GFC waiver.

The Utility also has funding available to construct a limited number of neighborhood sewer extension projects. Property owners that choose to connect with a new sewer project will be required to reimburse the City some portion of the cost of constructing the sewer infrastructure. In neighborhoods selected for a sewer extension project, the City will:

  • Provide a fixed cost up front prior to construction to help property owners prepare for financing;
  • Provide a payment plan ($200 per month) for properties that connect to the sewers that are constructed, and:
  • Cover payment of half of the sewer infrastructure cost over $20,000.

Neighborhood sewer extension projects will be selected based on the following criteria:

  • Neighborhood interest and commitment;
  • Occurrences of septic system failures;
  • Proximity to surface water and wellhead protection areas; and
  • Conditions which contribute to the likelihood of system failures as as the age of septic systems, poor soil conditions, and shallow groundwater.

The City continues to seek neighborhoods interested in sewer extension projects. The key factor in selecting a sewer extension project will be the neighborhood's level of interest and commitment. Sufficient interest is needed to make a project cost effective and successful.

Learn more; download our list of frequently asked questions. PDF Contact staff if you have any questions, need additional information, or would like assistance canvassing your neighborhood for interest in a sewer extension project.

Need More Information?

Contact City of Olympia Water Resources Wastewater Utility staff at 360.753.8562, or email, if you have any questions, need additional information, or would like assistance canvassing your neighborhood for interest in a sewer extension project.

Contact Information