On-site Sewer (Septic) Systems

The Board of Health’s Stakeholder Expert Technical Team is in the process of recommending changes to the regulations governing on-site sewer (septic) systems in King County. The revisions, which are required by April 2025, will likely be adopted before the end of this year to ensure septic system regulations - governing both existing systems, and construction of new septic systems—are consistent with recent changes to state law.

Seattle King County REALTORS® have utilized a multi-faceted approach to advocate successfully for common sense, science-based improvements to the Task Team’s recommended changes to the code:

• John L Scott broker Pam McCain, who is a member of SKCR’s Government Affairs Committee, and a Black Diamond Planning Commissioner, has been serving on the Expert Technical Team as the representative of SKCR and the real estate brokerage industry,
• SKCR’s lobbyist met directly with members of the Technical Team staff to explain and support requested changes, and also testified at the public hearings on the proposed code changes; and
• SKCR’s lobbyist also collaborated with members and staff of the Citizens Alliance for Property Rights (CAPR). The Alliance was active in reviewing and commenting on proposed changes, and mobilized owners of septic systems to comment on the proposal.

The collaboration continues partnership efforts which began in 2016 when SKCR and CAPR worked successfully to defeat a proposed “turd tax” on septic system owners, and followed-up with successful efforts to have the Legislature create a “Septic Owner’s Bill of Rights.”

Highlights of SKCR-supported changes we anticipate the Expert Technical Team will recommend to the Board of Health:

• Historically, regulation of septic systems has appeared to occur in an environmental silo, with little regard for the plethora of other Growth Management Act (GMA) goals. The Expert Technical Team recommendations expressly acknowledge the importance of addressing the Housing Supply Crisis, and the need to seek a “balanced” approach to the regulation of septic systems. This reflects a welcome, and important, “sea-change” in regulation of septic systems.

• Consistent with state law, the proposal recommends increasing to 1-year the amount of time a required septic system inspection report will be valid in connection with the purchase and sale of a property served by a septic system.

Currently, inspection reports on a septic system are only valid if the inspection was completed within 6-months of closing. As soon as the change is formally approved by the Board of Health, SKCR will notify the NWMLS so that Paragraph 4 of transaction addendum Form 22-S (for King County properties with septic systems) can be changed to reflect the additional period that septic system inspection reports will be valid.

• Reducing the minimum distance for separation of drain field trench side walls. The current regulations require 9-feet of separation, on-center. However, the best available science indicates only 4-feet is needed. So, the required distance will be reduced to 4-feet.

The change is important because it will accommodate “small” septic systems on environmentally-constrained properties, as well as on smaller lots, which will help with increasing the supply of housing.

This change will be especially important for the construction of new ADUs, not only in rural areas, but also in built-out unincorporated urban areas where sewers are not available. Although the City of Normandy Park is incorporated, ADUs will be critically important for the city’s ability to meet its housing targets. That’s also likely to be true in urban unincorporated areas that are not served by sewer.

• The proposed changes would eliminate the requirement for a property owner to obtain a permit for “minor” repairs or maintenance of septic systems. SKCR has requested a clear and objective definition of a “minor repair” to ensure septic system owners are not subjected to a $5,000 penalty for completing a modest repair they believed was minor in nature.

SKCR and CAPR have also requested language to make clear that in the event of a septic problem or system failure, septic system owners have a statutory right to repair or replace their system to good working order (rather than having to pay the high cost of connecting to sewer).