Skip to main content

On-site sewage system code revision process

This year, King County is revising the codes (rules) that govern on-site sewage systems (OSS). We are doing this to comply with recent changes to state law. We’re also using this opportunity to improve the codes and incorporate the latest best science.

Read and comment on draft codes

Based on technical and legal analysis, equity review, feedback from our customers and partners, and public input, we have drafted revised codes. Now, you can read and comment on the revised codes. We will then review and consider any additional public feedback before making final language and submitting the proposed revisions to the King County Board of Health in November.

Documents for review

Public comments on this draft proposed ordinance will be accepted through Thursday, October 10. They may be submitted via public comment survey, U.S. mail, or voicemail (see "How to comment" below). Note: Any public comments received are public records and are subject to public disclosure.

Frequently Asked Questions

No, if your septic system is functioning, no upgrades are necessary. The code changes make small changes to processes that already exist for septic system permitting and maintenance, so the only times when the new code revisions might impact an existing septic system is during a permitting or maintenance activity.

For example, one of the proposed changes is to require that all septic tank lids be secured to prevent risks of kids or pets falling into the tank. If this change goes into effect, the maintainer who next inspects your septic system would need to make sure that the lids are secured during that inspection.

No annual fee is being proposed. When this was proposed in 2016, we heard from community members that this was not a good idea, so we did not even consider proposing it as part of these code revisions.

No, Health Department inspectors do not go onto your property without your permission.

No, a septic system failure can be caused by many different things. If the tank or smaller parts of the septic system are broken, those can be easily and quickly fixed. If a drainfield fails, then the whole system would need to be replaced.

How to comment

  • Survey: Take the public comment survey
  • US Mail:
    Meagan Jackson
    Environmental Health Services
    14350 SE Eastgate Way
    Bellevue, WA 98007

Next steps

The King County Board of Health plans to vote on these code revisions in November. Whatever they approve will take effect in January 2025. We will share more information about what this means for you in late 2024/early 2025.

Background

In early 2024, the Washington State Department of Health approved new OSS codes. Since then, we have worked to figure out how to incorporate the state's changes into our local codes (our local codes are required by law to be at least as restrictive as the state's codes).

In early June, we launched a website and survey with proposed code revisions, in order to get public feedback. Over the course of this summer, we hosted 13 public meetings and received hundreds of comments.

Recently, we’ve incorporated that feedback into the proposed revisions and drafted revised codes. Now, we want to hear from you about the draft codes.

Key steps in the code revision process

  • March 2024

    State Board of Health finalizes revised OSS codes.
  • May – October 2024

    King County public engagement period - change to comment on possible local code revisions.
  • September - November 2024

    King County Board of Health reviews and votes on local code revisions.
  • January 2025

    Revised local codes go into effect.
expand_less