Marine Recovery Areas in Washington: What They Change

Sourced from chapter 70A.110 RCW (formerly chapter 70.118A RCW), WAC 246-272A-0015, the Washington State Department of Health and Public Health – Seattle & King County — last checked August 2026.

What a Marine Recovery Area actually is

RCW 70A.110.020 defines it as an area with definite boundaries where the local health officer — or the Department of Health, in consultation with that officer — determines that additional requirements for existing on-site sewage systems may be necessary to reduce failures or minimize their impact.

The purpose is water quality, and specifically shellfish. Under RCW 70A.110.040, a local health officer must designate a Marine Recovery Area where on-site systems significantly contribute to concerns about:

• Shellfish growing areas threatened or downgraded by the Department of Health
• Marine waters listed under section 303(d) for low dissolved oxygen or fecal coliform
• Marine waters where nitrogen is a contaminant of concern

The health officer proposes them in the on-site program management plan under RCW 70A.110.030, and must respond to a Department of Health designation recommendation within 90 days.

🔴 Only twelve counties — and this is the thing to know

Chapter 70A.110 RCW applies to the counties bordering Puget Sound and nowhere else:

Clallam · Island · Jefferson · King · Kitsap · Mason · Pierce · San Juan · Skagit · Snohomish · Thurston · Whatcom

That is twelve of Washington’s 39 counties. In the other twenty-seven, a Marine Recovery Area is not merely absent — it is legally impossible. If you are reading a general article about Washington septic rules that mentions Marine Recovery Areas and you live in eastern or central Washington, that section does not apply to you and never will. See what does apply in your county.

What it means if you are inside one

The Department of Health describes the duties it places on local health jurisdictions as: inventory and inspect all on-site systems within the area, identify failing systems and ensure they are repaired or replaced, and maintain electronic records that can be shared with other regulators.

⚠️ But the statute sets no homeowner inspection interval. That is the most commonly misunderstood part. RCW 70A.110 imposes duties on the jurisdiction, not a schedule on you. Your actual obligation is local.

The clearest published example is King County, which states that all septic systems in its Marine Recovery Area must be inspected annually by a certified maintainer, citing RCW 70A.110.040. Other counties within the twelve set their own terms, and you should confirm yours directly rather than assuming King County’s rule travels.

Note also RCW 70A.110.100, which says nothing in the chapter prohibits a county from relying on homeowner self-inspection consistent with RCW 36.70A.690. Some jurisdictions run homeowner certification programs; whether yours does is worth asking, because it is the cheapest compliance route where it exists.

🔴 We will not publish a list of designated areas, and here is why

You would expect a definitive list of which counties have actually designated a Marine Recovery Area. We could not source one, and the obvious candidate does not survive scrutiny.

The Department of Health publishes a map dated July 1, 2020, but it is titled for “Designated Areas of Puget Sound with Enhanced Inspection Reporting Requirements” and its legend explicitly combines two different categories — Marine Recovery Areas under chapter 70.118A RCW and other high-risk areas designated under WAC 246-272A-0015 with comparable requirements.

So the map cannot be read as a Marine Recovery Area list. Only the twelve-county statutory scope is properly sourced, and publishing a county-by-county designation list from that map would mean presenting two different legal mechanisms as if they were one. Ask your local health jurisdiction whether your specific parcel is inside a designated area. It is a question they can answer from a map and you cannot answer from a website.

The other mechanism, which does reach the whole state

If you are outside the twelve counties, the equivalent concept is not a Marine Recovery Area but the priority areas in WAC 246-272A-0015(2)(b). That rule requires every local management plan to identify areas where on-site systems could pose an increased public health risk, listing ten categories:

• Shellfish protection districts and growing areas
• EPA sole source aquifers
• Critical aquifer recharge areas under the Growth Management Act
• Group A wellhead protection areas under chapter 246-290 WAC
• Up-gradient areas influencing designated water recreation facilities
• Special protection areas under WAC 173-200-090
• Wetlands under crop production for human consumption
• Frequently flooded areas
• Areas where nitrogen is a contaminant of concern, including Puget Sound marine waters
• Areas where phosphorus is a contaminant of concern

🎯 That list applies statewide, and it is why an eastern Washington county over a sole source aquifer can run a tighter program than the rule’s minimum without any marine connection at all.

The Department of Health calls areas designated this way “Enhanced Management Areas.” ⚠️ That is a Department label, not a defined term in the rule — which is exactly why its map blends the two categories together.

How this interacts with the 2027 inspection

If you are in a Marine Recovery Area on an annual inspection cycle, you are already generating the record that the 2027 property-transfer waiver depends on. That is an advantage worth knowing about — the waiver turns on documented compliance with your inspection frequency plus an inspection by an authorized third-party inspector, and an MRA regime tends to produce both as a matter of routine.

See whether your county can waive the 2027 inspection and what your inspection schedule actually is.

What we could not source

• Which of the twelve counties have actually designated Marine Recovery Areas, and where their boundaries run — the only candidate map merges two legal categories
• Homeowner inspection intervals for eleven of the twelve — only King County publishes one we could retrieve
• Which jurisdictions run homeowner self-inspection certification under RCW 70A.110.100

This site is an independent information resource. We are not a health jurisdiction and we are not affiliated with the Washington State Department of Health or any county health department. Whether your parcel sits inside a designated area is a question only your local health jurisdiction can answer.

Sources

• RCW 70A.110.020, definitions including Marine Recovery Area — statute
• RCW 70A.110.040, designation of Marine Recovery Areas — statute
• RCW 70A.110.100, self-inspection — statute
• WAC 246-272A-0015, local management plans and priority areas — rule text
• WA Dept of Health, on-site sewage management areas — page
• Public Health – Seattle & King County, Marine Recovery Area — page

Last reviewed August 2026. Marine Recovery Areas exist only in the twelve Puget Sound counties; if you are elsewhere in Washington, the priority areas in WAC 246-272A-0015 are the equivalent mechanism.