Septic Tank Pumping in King County, WA

• Coverage across the septic areas: Vashon, Maury Island, Enumclaw, Black Diamond, Maple Valley, Hobart, Ravensdale, Covington, Duvall, Carnation, Fall City, North Bend and Skykomish.
• Crews run I-90, SR 18, SR 169, SR 203 and SR 410, with ferry scheduling for Vashon jobs.
• Island jobs book further ahead because trucks travel by ferry; plan routine Vashon pump-outs early.

• Pump-outs combined with the required O&M inspection
• Inspection reports for home sales
• Repairs and limited repairs with a county permit
• Pressure system and pump servicing
• Riser and lid upgrades for easier inspection
• Emergency backups

• HomeGuide's national pump-out range is $300 to $700, based on $0.30 to $0.70 per gallon of tank size.
• HomeGuide lists an inspection at $150 to $450 and filter cleaning at $100 to $400, which matters here because many King County systems carry a required inspection schedule.
• County fees from Public Health's 2026 schedule: $34 to file a routine O&M inspection report, $225 for a property-transfer inspection report, $619 for a single-family repair permit and $281 for a limited repair.
• Method: HomeGuide's published per-gallon range scaled to your tank, plus the county fee schedule for reports and permits. Ferry time on Vashon and long hauls from the Snoqualmie Valley add local cost.

• Step 1, records: Public Health - Seattle & King County holds the as-built (record drawing) for permitted systems; request it before a repair or sale.
• Step 2, inspection schedule: under WAC 246-272A-0270 and Board of Health Code Title 13, gravity systems are inspected every 3 years and pressure or proprietary systems every year, and the county's 2026 fee for filing a routine O&M report is $34.
• Step 3, home sale: a property-transfer inspection report costs $225 to file, and the buyer pays a $40 O&M program fee at the time of sale, per the county's fee schedule.
• Step 4, repairs: a single-family repair permit is $619 and a limited repair $281 under the county's fee schedule; repair or replacement plans and specifications are reviewed for $731, and an owner-occupied home with a failing system can get a replacement design reviewed for $450.

• Glacial till: hardpan soils under the plateaus east of Maple Valley and around Enumclaw perch water in winter, so fields there sit in a seasonal water table after heavy rainfall.
• River floodplains: silty soils along the Snoqualmie River near Carnation and Fall City floods in winter storms, and systems near the river need care after high water.
• Island sand: Vashon-Maury Island relies on its own groundwater, and sandy soils near the shoreline drain quickly toward it.
• Slope: steep lots near North Bend and in the Cascade foothills limit where a replacement field can go.
• USDA NRCS soil survey data for the King County Area (survey WA633) map 50,803 of 414,219 acres, 12.3%, as poorly drained and 39,542 acres, 9.5%, with a water table within about 12 inches of the surface.
• Older homes: rural houses built before the 1980s in the Snoqualmie Valley often predate today's inspection rules.

Vashon · Maury Island · Enumclaw · Black Diamond · Maple Valley · Hobart · Ravensdale · Duvall · Carnation · Fall City · North Bend