Washington State

House of Representatives

Office of Program Research



Environment Committee

ESSB 5281

This analysis was prepared by non-partisan legislative staff for the use of legislative members in their deliberations. This analysis is not a part of the legislation nor does it constitute a statement of legislative intent.

Brief Description: Concerning rules for on-site sewage systems.

Sponsors: Senate Committee on Local Government (originally sponsored by Senators Angel, Fortunato, Takko, Fain, Sheldon and Hobbs).

Brief Summary of Engrossed Substitute Bill

  • Restricts state Board of Health and local rules related to on-site sewage systems (OSS) from requiring private monitoring contracts to be a condition of OSS use permits, from requiring dedicated easements for certain OSS activities, or from requiring the replacement of OSS in certain circumstances.

Hearing Date: 3/21/17

Staff: Jacob Lipson (786-7196).


The state Board of Health (BOH) adopts rules addressing the design, construction, installation, operation, and maintenance of on-site sewage systems (OSS) with design flows of less than 3,500 gallons per day. Local health jurisdictions (LHJ) in each county administer and enforce those OSS regulations alongside any additional or discrepant local requirements. The LHJs in all counties must develop a written plan for managing OSS; additional plan requirements apply only to the 12 marine counties bordering the Puget Sound.

As part of their OSS plans, LHJs are authorized to require OSS owners to, among other criteria, provide dedicated easements for inspections, maintenance, and potential future OSS expansions. In addition, prior to issuing an installation permit for an OSS serving more than one development, LHJs must require a recorded easement allowing access for OSS construction, operation, monitoring, maintenance, and repair.

On-Site Sewage System Inspections, Operations, and Maintenance.

Owners of an OSS are generally responsible for maintaining the OSS, including associated repair and upkeep costs. Once an OSS system has been installed, the systems must be inspected at least once every three years if the system has a septic tank and relies on a gravity-powered drain field, or at least once per year for other types of OSS, unless a LHJ requires more frequent inspections. Under BOH rules, LHJs may require OSS operation permits, and may require owners to secure and renew contracts for periodic maintenance.

On-Site Sewage System Failures.

When an OSS fails, BOH rules require OSS owners to:

Mandatory Connections to Public Sanitary Sewer Systems.

Upon the failure of an existing OSS, a LHJ may require connection to a public sewer system if adequate public sewer services are available within 200 feet of the residence or facility. If a conforming system can be designed and installed, the LHJ may also permit the repair or replacement of the OSS.

The owner of a residence or other facility served by an OSS may also be required to connect to a public sewer system when:

An OSS repair or replacement may take place either on the property served by the OSS, or a nearby property if easements are obtained.

Summary of Bill:

The BOH and LHJ rules for OSS with design flows of less than 3,500 gallons per day may not require:

Appropriation: None.

Fiscal Note: Not requested.

Effective Date: The bill takes effect 90 days after adjournment of the session in which the bill is passed.