Bolthole Index county-legal census · checked 2026-08-08
Septic permitting in Washington is mixed: 24 counties use county health departments, 0 go through a state agency, and 15 through regional districts.Every entry below names the approving authority for that county, cited to the authority’s own page.
Septic rules change and some cities run their own programs — treat this as a verified starting point, not legal advice. All states → Washington water rights & wells → Full Washington profile →
39 counties · mixed — varies by county · permit status scouted for 3
Adams County Health Department — Environmental Health
Adams County Code — Ch. 13.06 On-Site Sewage Systems ↗Asotin County Health District (On-site Sewage program)
Asotin County Health District - On-site Sewage ↗Benton-Franklin Health District (local health jurisdiction under WA DOH)
Benton-Franklin Health District - On-Site Sewage ↗Chelan-Douglas Health District
Chelan-Douglas Health District - On-Site Septic Program ↗Clallam County Environmental Health Services
Clallam County Septic System Permits ↗Clark County Public Health
Clark County WA - On-site Septic Systems ↗Columbia County Public Health – Environmental Health (On-Site Sewage Program)
Columbia County Public Health – Land Development / On-Site Sewage ↗Cowlitz County Health Department - Environmental Health Unit (EHU)
Cowlitz County - Environmental Health Unit (EHU) ↗Chelan-Douglas Health District (Environmental Health)
Chelan Douglas Health District On-Site Septic Permitting ↗Northeast Tri County Health District
Northeast Tri County Health District - Septic Permit Applications ↗Benton-Franklin Health District
Benton-Franklin Health District On-Site Sewage ↗Garfield County Public Health (local health jurisdiction, with Asotin County Environmental Health Administrator)
Garfield County Public Health - Septic ↗Grant County Health District
Grant County Health District - On-Site Septic Systems ↗Grays Harbor County Environmental Health Division (On-Site Sewage Section)
Grays Harbor County Environmental Health Division - On-Site Sewage Section ↗Island County Public Health - Environmental Health (Onsite Sewage Program)
Island County Onsite Sewage (Septic) Systems ↗Jefferson County Public Health
Jefferson County Code Chapter 8.15 - On-Site Sewage Code ↗Public Health - Seattle & King County (On-site Sewage System program)
Public Health - Seattle & King County - New Septic Design and Installation ↗Kitsap Public Health District
Kitsap County DCD (septic via Kitsap Public Health District) ↗Kittitas County Public Health Department, On-Site Sewage (Liquid Waste) Program
Kittitas County Public Health - Liquid Waste ↗Klickitat County Health Department, Environmental Health
Klickitat County, WA - On-Site Septic Program ↗Lewis County Environmental Health, On-Site Septic Program
Lewis County Environmental Health On-Site Septic Program ↗Lincoln County Public Health, Environmental Health Department
Lincoln County Public Health - Onsite Sewage Systems ↗Mason County Community Services, Environmental Health (On-Site Sewage Program)
Mason County Environmental Health - OSS Permits ↗Okanogan County Public Health District (OCPHD), Environmental Health
Okanogan County Onsite Septic / Liquid Waste ↗Pacific County Environmental Health Division / Board of Health (Dept. of Community Development)
Pacific County WA DCD - Septic ↗Northeast Tri County Health District (NETCHD)
Pend Oreille County Community Development - Building FAQ's ↗Tacoma-Pierce County Health Department
Pierce County Development Center (septic reviewed by Tacoma-Pierce County Health Dept) ↗San Juan County Health & Community Services (Environmental Health)
San Juan County WA - On-Site Sewage Program ↗Skagit County Public Health - On-Site Sewage Program
Skagit County - On-Site Sewage Program Information ↗Skamania County Community Development, Environmental Health On-Site Sewage Program
Skamania County On-Site Sewage Program ↗Snohomish County Health Department – Environmental Health Division
Snohomish County Health Department – Septic Permitting ↗Spokane Regional Health District
Spokane Regional Health District — Septic Systems ↗Northeast Tri County Health District (Environmental Health Department)
Northeast Tri County Health District - Septic Permit Applications ↗Thurston County Public Health & Social Services, Environmental Health
Thurston County - Septic Systems Permits & Resources ↗Wahkiakum County Health & Human Services (Public Health / Environmental Health)
Wahkiakum County - On-Site Septic System Permits ↗Walla Walla County Department of Community Health, Environmental Health (under WA Dept of Health)
Walla Walla County Dept of Community Health - Onsite Permitting Process ↗Whatcom County Health and Community Services (local health jurisdiction, On-Site Sewage program)
Whatcom County - When is an OSS permit needed? ↗Whitman County Public Health, Environmental Health Division
Whitman County Public Health - Onsite Septic ↗Yakima Health District (Yakima County on-site sewage program)
Yakima County Septic Systems ↗Every county here has a full profile — its index score, water, land prices, and the rest of its building rules. See the Washington state page for all counties ranked, or the national septic guide.
General guidance, not legal advice. Off-grid, building, and land-use rules are often set at the county level and change often. Verify with your county and state before acting. Data reviewed 2026-06-26.
