Septic rules and requirements in Whatcom County, Washington

Septic permits in Whatcom County are issued by the Whatcom County Health and Community Services, On-Site Sewage (OSS) Program. A new system permit costs $1,099. USDA rates most of the soil in the county Very limited for septic absorption fields — 99.2% of the rated acres. Whatcom County — On-Site Sewage · checked 2026-09-23

Whatcom County Health and Community Services, On-Site Sewage (OSS) Program

Issues the permit

checked 2026-09-23

$1,099

Septic system permit

checked 2026-09-23

Very limited

USDA rating, 99.2% of rated acres

checked 2026-09-13

Who issues septic permits in Whatcom County?

Whatcom County Health and Community Services, On-Site Sewage (OSS) Program, at 509 Girard Street, Bellingham, WA 98225, 360-778-6000. It is part of county government. The state writes the rules it applies.

This program permits and inspects septic systems for the county. It enforces county code 24.05.

Whatcom County — On-Site Sewage · checked 2026-09-23

What does a septic permit cost in Whatcom County?

$1,099 for a septic system permit, on the county's own schedule.

Applies to a new, repair or expansion permit. The county adds a 5 percent technology fee.

The county's fee table for this permit
Fee for a new, repair or expansion application and permit shown above	$1,099.35	a system the source lists as new, repair or expansion application and permit
Fee for a tank only application and permit	$576.45	a system the source lists as tank only application and permit

Whatcom County sets a lower fee for a tank-only permit. Both fees add the same technology fee. The county's fee schedule sets both rates. The state code sets no fee amount.

Whatcom County Health and Community Services — On-Site Sewage System Permit Process · checked 2026-09-23

What does an inspection cost in Whatcom County?

These are prices, not permit fees. Each one comes from a government source.

$337 for an inspection.

Applies to a re-inspection of a septic dispersal field. The county bills it per visit.

Whatcom County lists this fee in its Unified Fee Schedule, under Environmental Health.

Whatcom County — 2025-2026 Unified Fee Schedule · checked 2026-09-23

Is the soil in Whatcom County suitable for a septic system?

USDA rates most of the county Very limited for septic absorption fields — 99.2% of the rated acres. A rating describes the ground, not a parcel. The county's site evaluation decides each lot.

Very limited — 941,932 acres — 99.2% of 949,429 rated acres.
Somewhat limited — 7,497 acres — 0.8% of 949,429 rated acres.
Not rated — 113,314 acres, excluded from the denominator — mostly urban land and water.

USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-13

Does Whatcom County inspect a septic system when a house is sold?

Yes, starting in 2027. The owner must have a third-party inspector check the system when the property changes hands.

The county health officer may waive this if the system already passed its regular check. State law sets this same rule statewide.

Whatcom County Code § 24.05.280, Operation, Monitoring and Maintenance · checked 2026-09-23

What Whatcom County sets itself

The state writes the code. Whatcom County adds the rules below. They are what makes this page differ from the Washington requirements.

$1,099

Applies to a new, repair or expansion permit. The county adds a 5 percent technology fee.

Whatcom County sets a lower fee for a tank-only permit. Both fees add the same technology fee. The county's fee schedule sets both rates. The state code sets no fee amount.

Whatcom County Health and Community Services — On-Site Sewage System Permit Process · checked 2026-09-23
$19

Applies to every septic system in the county. The county bills it with the property tax.

The county council set this fee in 2013. It funds the county's septic maintenance program. It replaced an older filing fee and a per-gallon fee. The county bills half in April and half in October. State law lets the county collect the fee this way.

Whatcom County — OSS Annual Fee · checked 2026-09-23
Whatcom County approves septic installers, pumpers and maintenance workers. Each one passes an exam and posts a bond with the county.

Applies to an installer, a pumper or a maintenance worker. The county approves each one.

State law tells the county to set up this approval process. It does not set the exam or the bond. The county sets both in its own code. The county renews each approval every December.

Whatcom County Code § 24.05.380, Licensing · checked 2026-09-23

Sources

Each figure above has a government source and a checked-on date. USDA's Soil Data Access service supplies the soil records. A script writes them, and nobody types them.

Whatcom County — On-Site Sewage · checked 2026-09-23
Whatcom County Health and Community Services — Septic Forms & Applications · checked 2026-09-23
Whatcom County — OSS Annual Fee · checked 2026-09-23
Whatcom County Code § 24.05.380, Licensing · checked 2026-09-23
Whatcom County Health and Community Services — On-Site Sewage System Permit Process · checked 2026-09-23
Washington Administrative Code § 246-272A-0232, Design Requirements — Septic Tank Sizing · checked 2026-09-23
Washington Administrative Code § 246-272A-0210, Location, Table IV · checked 2026-09-23
USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-13
Whatcom County — 2025-2026 Unified Fee Schedule · checked 2026-09-23

Verify before you act. Septic rules are set locally and they change. Check anything here before you spend money on it. Call the Whatcom County Health and Community Services, On-Site Sewage (OSS) Program, on 360-778-6000.