Chelan and Douglas County Septic Permits and the 2027 Inspection

Sourced from the Chelan-Douglas Health District’s on-site septic program pages, its OSS Application Types instructions document, its published WAC 246-272A code revision handout dated February 2025, and chapter 246-272A WAC — last checked August 2026. Where we could not source something, we say so.

One district, two counties

The Chelan-Douglas Health District permits septic systems across both Chelan and Douglas counties from a single office in East Wenatchee. If you are comparing quotes or rules across the county line here, you are comparing the same rules — the district licenses all installers, operation and maintenance providers and pumpers for both counties.

Every step needs a professional

Most Washington counties leave homeowners at least one opening. Klickitat lets you design and install a simple gravity system yourself. Kittitas lets you design your own after a pre-design meeting. Walla Walla stopped homeowner design in 2023 but still lets you install. Chelan-Douglas closes all three doors:

Stage	Who may do it
Site and soil evaluation	A licensed designer or professional engineer. The district also offers this service — but it does not dig your test pits and does not produce your design.
System design	A licensed designer or professional engineer. Submitted with the application.
Installation	A licensed installer. No homeowner installation.
Final inspection	The district itself, on request by email, with one to two business days notice.

There is a scheduling consequence buried in that last row that is easy to miss: a permit is only issued once a designated licensed installer has been established. You cannot get the permit in hand and then go shopping for a contractor. The installer has to be named first.

Water first

Before a septic permit can issue, the district needs proof of water. Under RCW 19.27.097 you must supply either a separate private water review application or a public water will-serve letter alongside your septic application.

On timing, the district publishes both its own expectation and the statutory backstop: review time varies from two to three weeks depending on workload, and under RCW 70.05.074 the application must be reviewed within 30 days.

The permits expire, and there is no grace period

This is the part of Chelan-Douglas that costs people real money, and the district states it twice in its own instructions.

Permit type	Life
New construction	Expires after two years, renewable twice
Repair	Expires after six months, renewable once, depending on circumstances
Absolute maximum	A permit is valid for no more than five years, however many renewals

The renewal application must be submitted before the permit expires. The district’s phrasing is blunt: “(no grace period).” Miss the date and there is no renewal to apply for — you start again as a new construction permit.

The rules got tighter on April 1, 2025

The district published a handout explaining how the revised WAC 246-272A requirements, in effect from April 1, 2025, change what you can build. Two of the changes decide whether a lot works at all.

The usable land “box”

New lots and existing undeveloped lots served by septic must have a defined area of genuinely usable land, shown as a box on the design site plan and containing just the primary and reserve drainfields. It cannot be under water, paved, too steep, crossed by an easement, under a deck, or otherwise unusable.

Soil type	1	2	3	4	5	6
Minimum usable land area	2,000 sq ft	2,000 sq ft	2,500 sq ft	3,333 sq ft	5,000 sq ft	10,000 sq ft

Minimum lot sizes

Minimums rose by 500 to 1,000 square feet depending on soil type and water source. The district prints them as follows:

Soil type	1	2	3	4	5	6
Public water	21,780 sq ft (2.5 acre gravity drainfield)	13,000 sq ft	16,000 sq ft	19,000 sq ft	21,000 sq ft	23,000 sq ft
Individual or shared well	1.0 acre (2.5 acre gravity drainfield)	1.0 acre	1.0 acre	1.0 acre	2.0 acres	2.0 acres

We have reproduced the soil type 1 entries exactly as the district prints them, parenthetical and all, because the parenthetical changes the answer substantially and we are not going to paraphrase it into something it might not mean. If your parcel is soil type 1, ask the district directly which figure applies to your design.

The sentence attached to that table is the one to notice: new or existing undeveloped lots below the minimum will not qualify for any septic system waivers. A small lot that might once have been argued through no longer can be.

There is one relief valve. Under a nitrogen-based provision, new lots may go smaller than the table — but no smaller than 13,000 square feet — if certain safety measures are met and nitrogen treatment is installed. Existing undeveloped small lots may be approved with fewer bedrooms, nitrogen treatment, or both.

New setbacks, and two easings

Distance	From the drainfield to
100 feet	An unlined stormwater detention pond, up or down gradient
100 feet	Irrigation ponds or canals, lined or unlined
30 feet	An on-lot stormwater component, up or down gradient

These may sit on the lot being developed or on a neighboring lot, which is why the district asks for them on the site plan.

Two changes went the other way, and both are worth knowing if you are facing a repair bill:

• Drainfield areas can shrink by 17 to 29 percent where sewage is treated to a higher standard before it reaches the soil. This applies to primary and reserve areas, but cannot be combined with a gravelless drainfield reduction.
• Remediation of a failing system is now allowed under permit, under certain conditions, instead of a full drainfield replacement. That is a genuinely cheaper path where it applies.

Time-of-sale inspections, named and dated

Most Washington counties say nothing about the 2027 change. Chelan-Douglas put it in writing:

“Time-of-sale inspections of all existing OSS prior to transfer of deed or property (to be effective by February 2027 as the Health District is currently developing this program).”

Three things are worth separating out of that one sentence. It applies to all existing systems, not just new ones. It is tied to transfer of deed or property, so it lands at closing. And the district says it is currently developing the program — meaning the requirement is settled but the mechanics, the approved inspector list and the cost were not published when we checked.

If you expect to sell in Chelan or Douglas County in 2027, this is the district to watch, because it is the one that has already committed to the date in public.

Proposed, not adopted

The same handout carries a second list under the heading “Proposed under Chelan-Douglas Health Code as of February 24, 2025.” These were proposals at that date and we could not confirm whether they have since been adopted, so treat them as questions to ask rather than rules to plan around:

• Renewable operational permits for certain new and repaired systems using UV light disinfection, aerobic treatment units, or Table IX repairs.
• A 5-foot setback between primary and reserve drainfields on the same property.
• For an accessory dwelling unit served by the main home’s system: a minimum design flow of 120 gallons per bedroom or per building connection, whichever is greater. Detached shops or garages with only a toilet and sink would be exempt. This may require expanding the existing system, tanks or drainfield included, before ADU occupancy is approved.

That last one matters to anyone planning an ADU on an existing system, so it is worth a direct call before committing to a build.

What we could not source

• 🔴 Any fee schedule whatsoever. This is the largest single gap we have found in Washington. The district publishes twelve separate application types with detailed instructions and not one dollar amount anywhere in them. We are not going to estimate. Call before you budget.
• The cost or process of the coming time-of-sale inspection, who will be permitted to perform it, or what form it will use. The district says the program is under development.
• Whether the February 2025 proposals were adopted. Eighteen months on, we found no published confirmation either way.
• Any local rule requiring connection to public sewer within a set distance. We have seen this attributed to the district but could not find it published, so we are not repeating it as fact.
• A consolidated local health code document. The district’s resource pages link to the state WAC rather than to its own code.
• How many on-site systems are in the two counties. Not published anywhere we could find.

The practical bits

Chelan-Douglas Health District	200 Valley Mall Parkway, East Wenatchee, WA 98802
Main line	(509) 886-6400
Local code and septic questions	Richmond Petty, (509) 886-6432
Inspection requests	inspections@cdhd.wa.gov — one to two business days notice
If no response in two business days	Call the main line

Sources

• Chelan-Douglas Health District, On-Site Septic Permitting Process — cdhd.wa.gov
• Chelan-Douglas Health District, On-Site Septic Application Types and Instructions — cdhd.wa.gov
• Chelan-Douglas Health District, WAC 246-272A code revision handout, February 2025
• Chelan-Douglas Health District, Septic System Resources — cdhd.wa.gov
• WAC 246-272A; RCW 19.27.097; RCW 70.05.074