Washington State · Rule Change Tracker

Washington Septic Rule Changes: A Dated Tracker

Washington's septic rule, WAC 246-272A, went through a major revision that started in 2024 and is still phasing in. A second, narrower rulemaking opened in 2026. This page tracks what changed, when it changed, who it affects, and links the primary source for every entry — newest first.

Last updated July 22, 2026. We update this page when Washington septic rules change.

This is a tracker, not legal advice. Effective dates and rule text come from Washington's official rulemaking record. Confirm anything that affects a specific sale or permit with your county environmental health department.

Not in effect yet

Coming February 1, 2027: Septic Inspection Becomes Mandatory at Every Sale, Statewide

The rule itself is exact: "Beginning February 1, 2027, obtain an inspection, as required in WAC 246-272A-0260(5), by a third-party inspector authorized by the local health officer." (WAC 246-272A-0270(1)(k)(ii)) A local health officer can waive it if evidence shows the system is already compliant and was recently inspected by an authorized third-party inspector.

This closes a gap that exists today: several counties don't yet run their own septic inspection requirement at property transfer, so nothing currently forces an inspection when those properties sell. February 1, 2027 makes transfer inspection mandatory everywhere in the state. (snohd.org — Property Transfer)

Some counties already require this. King, Skagit, Island, and Whatcom counties already run their own transfer-inspection programs. Kitsap requires a Property Conveyance Inspection and Pierce requires a Report of System Status at sale; see our Kitsap and Pierce county guides for the specifics. For those counties, the 2027 date changes little. See our Thurston County Septic Regulations guide if you're in the tri-county area.

Snohomish County shows what statewide compliance is likely to look like. Its Board of Health adopted a local ordinance requiring septic inspection before any property sale, ahead of the state deadline, effective November 1, 2026. Under that ordinance: inspection by a certified septic professional, with the tank pumped if the inspection report recommends it; the report is valid for up to 12 months before closing; systems installed within the prior 12 months are exempt; report review takes up to 10 days; the inspection report fee is reported at $245 under the 2026–27 schedule, rising to $255 for 2027–28, per Lynnwood Times' coverage of the ordinance — the county's own fee page doesn't list this line item; and any unresolved deficiency transfers to the buyer if the seller doesn't fix it first. The county has roughly 84,000 septic systems and about 2,785–2,800 properties change ownership there each year. (Lynnwood Times, snohd.org, snohd.org newsflash)

If you're selling a house with a septic system, read Selling a House With a Septic System in Washington for what this mandate means for your closing timeline.

2026: Active Rulemaking to Watch

Two separate things are moving through the system in 2026: a narrow state rulemaking that only touches one setback distance, and one legislative fix to septic-inspector training. Neither reopens the full 2024 rule package below.

November 1, 2026 Upcoming

Snohomish County's own transfer-inspection ordinance takes effect

Who it affects: Snohomish County property sellers and buyers, more than a year ahead of the statewide February 2027 deadline.

Full detail is in the box above. One number to flag: a secondary source cites the ordinance as "BOH26-02," which we couldn't independently confirm against a primary Snohomish County Board of Health ordinance record.

Sources: lynnwoodtimes.com · snohd.org

July 21, 2026 Proposed rule — comment open

Surface-water setback clarification reaches CR-102, the formal proposed-rule stage

Who it affects: owners and builders near rivers or other surface water used as a public drinking-water source — mostly a handful of rural, border counties like Pend Oreille. Nothing changes yet; this rule is not adopted.

The Washington State Board of Health filed the CR-102 proposed rule for chapter 246-272A, following an April 9, 2026 virtual workshop with local health jurisdictions and county officials. The proposal would amend WAC 246-272A-0210 to clarify how the minimum horizontal separation for surface water used as a drinking-water source is measured and applied. Public comment is open through September 17, 2026, 11:59 p.m. A public hearing is scheduled for October 1, 2026, 1:30 p.m., at the Norm Dicks Government Center Auditorium, 345 6th St., Bremerton, WA 98337, with virtual attendance also offered.

How to comment. Email [email protected] or submit through fortress.wa.gov/doh/policyreview before the September 17, 2026 deadline.

Source: doh.wa.gov — Site sewage systems setbacks

Reported effective June 11, 2026 Reported, lower confidence

SB 6291 extends the septic-inspector apprenticeship window from two years to four

Who it affects: septic-inspector trainees and the local health jurisdictions that supervise them. Not a change to setbacks or the property-transfer mandate.

Confirmed against the primary House Bill Report: SB 6291 (sponsors Sen. Lovelett and Sen. Shewmake) increases, from two years to four, the maximum period a noncertified individual may review designs and conduct on-site sewage system inspections under the supervision of a BRPELS-certified professional. It addresses a workforce bottleneck — the certification exam is only offered twice a year, and local health jurisdictions were losing apprentices who couldn't test in time. The House Environment & Energy Committee passed an amended version on February 24, 2026; the full House passed it 93-0 on March 3, 2026. Per the bill report, it takes effect 90 days after adjournment of the session that passed it.

A secondary legislative tracker additionally reports the Senate passed it 48-0 on February 10, 2026, the Senate concurred in House amendments 49-0 on March 10, 2026, the Governor signed it March 24, 2026, and it took effect as chapter 210 of the 2026 session laws on June 11, 2026. We haven't independently checked those four dates against the Legislature's own bill-history page, so treat them as reported rather than confirmed.

Sources: House Bill Report, SB 6291 (PDF) · LegiScan bill history

Spring 2026, exact date unconfirmed Reported, lower confidence

DOH issues Interpretive Statement EHS-04-2026 on the surface-water setback

Who it affects: local health officers evaluating permit applications near drinking-water sources, while the CR-102 rulemaking above is still open.

This interpretive statement gives local health officers interim guidance on applying the 200-foot surface-water setback while formal rulemaking continues. DOH's own rulemaking narrative says it "plans to issue" the statement in April 2026, while DOH's interpretive-statement activity listing files it under WSR issue 26-11, which corresponds to early May 2026. We weren't able to pull the exact issue date from the underlying PDF, so this entry carries a real date range rather than one confirmed day.

Sources: doh.wa.gov — Interpretive statement activity · doh.wa.gov — Setbacks

March 6, 2026, 9:25 a.m. Filed

CR-101 filed, formally opening the setback-clarification rulemaking

Who it affects: the same border-county property owners as the July 2026 entry above — this is the procedural start of that process.

The State Board of Health filed WSR 26-07-010, a Preproposal Statement of Inquiry proposing to amend WAC 246-272A-0210 to "clarify the minimum horizontal separations for surface water used as a public and nonpublic drinking water source," along with a short list of technical corrections elsewhere in the chapter, including NSF/ANSI citation-date fixes.

Source: WSR 26-07-010 (leg.wa.gov)

February 23, 2026 In effect

Interpretive Statement EHS-02-2026 takes effect, clarifying shared septic systems

Who it affects: owners and developers of a privately-owned on-site sewage system that serves more than one development.

WSR 26-07-092 clarifies WAC 246-272A-0200(6), which governs a privately owned OSS serving more than one development. It's unrelated to the setback rulemaking above — a separate 2026 interpretive action worth tracking on its own.

Source: doh.wa.gov — Rulemaking activity

January 14, 2026 Procedural

State Board of Health votes to begin the setback-clarification rulemaking

Who it affects: property owners along rivers used as drinking-water sources, mainly in northeast Washington counties like Pend Oreille.

The vote followed a petition filed in November 2025 by the Northeast Tri-County Health District and the Pend Oreille County Commissioners. Their argument: the 2024 rule's 200-foot public-drinking-water setback was being applied along a river's entire length, regardless of where the actual drinking-water intake sits, which blocked development on upstream parcels miles from any intake. County Commissioner Robert Rosencrantz appeared before the Board in person to make the case.

Sources: sboh.wa.gov · Pend Oreille River Valley

2023–2025: How the Current Rule Came Together

Everything above sits on top of a bigger revision. The State Board of Health adopted a full rewrite of WAC 246-272A on January 10, 2024, and rolled it out in stages instead of all at once. That rollout is done except for one piece: the property-transfer inspection mandate covered above.

April 1, 2025 In effect

Most of the revised WAC 246-272A rule takes effect

Who it affects: anyone installing a new system, buying an undersized or unusual lot, repairing an existing system, or using a proprietary treatment product, statewide.

This is the date most of the 2024 rule package actually started applying: a new "Minor Repair" definition that doesn't require a permit for some repairs; a rule requiring the local health officer to allow the least-expensive compliant repair option, evaluate unpermitted discharges, and report OSS failures within 200 feet of shellfish-growing areas to DOH; a new LHO remediation-policy option; minimum lot sizes increased by 500–1,000 square feet depending on soil type; a new "minimum usable land area" requirement for new lots; field verification at 25 in-state installations before a proprietary disinfecting or nitrogen-treating product can be used, with a supply-chain retrofit allowance; and "resilience" provisions requiring Puget Sound county health officers to map sea-level-rise and phosphorus impacts on OSS siting. A related, narrower rulemaking on proprietary-product testing standards (WSR 25-06-036) reached final adoption on February 26, 2025 and took effect the same day.

Sources: doh.wa.gov — Rule revision · DOH Key Draft Rule Changes (PDF) · WSR 25-06-036

February 1, 2025 In effect

Maintenance Service Provider approval requirement takes effect

Who it affects: O&M providers, and any system owner scheduling a required inspection.

Anyone performing the periodic operation-and-maintenance inspection a system requires now has to be a provider the local health officer has approved, with results submitted on an approved form. Before this date, that approval step wasn't a formal requirement under the rule.

Source: doh.wa.gov — Rule revision

April 1, 2024 In effect

First tranche of the revised rule takes effect: WAC 246-272A-0110

Who it affects: statewide, a narrower technical scope than the April 2025 wave above.

This was the earliest piece of the 2024 revision to actually apply, roughly three months after the Board adopted the full rewrite.

Source: doh.wa.gov — Rule revision

January 10, 2024 Adopted

State Board of Health adopts the revised WAC 246-272A

Who it affects: everyone in Washington subject to on-site sewage system rules, though most provisions didn't apply until the later effective dates above.

This is the adoption date for the biggest septic-rule overhaul in recent years. Locked in that day: the new property-transfer inspection requirement (effective February 1, 2027, covered at the top of this page); an increase in the minimum setback between a system and surface water used as a public drinking-water source, from 100 feet to 200 feet, measured from the ordinary high-water mark (Table IV, WAC 246-272A-0210); and the full list of provisions under the April 2025 entry above. The Board scheduled the rollout in stages rather than putting all of it into effect the same day.

Sources: doh.wa.gov — Rule revision · doh.wa.gov — Setbacks

October 25, 2023 Filed

Proposed rule filed, opening the rulemaking that produced the 2024 revision

Who it affects: this is the starting gun for the entire 2024–2027 rule package described on this page.

The State Board of Health filed WSR 23-22-062. The public comment deadline was November 28, 2023, and the adoption hearing followed on January 10, 2024, the date above.

Source: WSR 23-22-062 (leg.wa.gov)

Primary Sources

Every date and fee on this page is sourced directly to the Legislature, the Department of Health, the State Board of Health, or a named county. Where a fact came from a secondary source instead, we said so in that entry.

This page is general information about how Washington's septic rules are changing over time. It is not legal advice, and some entries above are flagged as lower-confidence where our research relied on a secondary source rather than a primary record. Confirm anything that affects a specific sale, permit, or deadline with your county environmental health department or a licensed professional.