Service price ranges
| Device | Size | Typical cost per service* | County clock |
|---|---|---|---|
| Under-sink trap | 20–50 gal | $125–$225 | every 30 days / 25% |
| Under-sink trap | 75–100 gal | $175–$300 | every 30 days / 25% |
| Interceptor | 500–1,000 gal | $300–$650 | every 90 days / 25% |
| Interceptor | 1,500–2,000 gal | $500–$1,000 | every 90 days / 25% |
| Large interceptor | 3,000+ gal | $850–$1,500 | every 90 days / 25% |
*Ranges for scheduled service so you can sanity-check any quote. The only Spokane operator we found publishing a grease figure says a cleaning “will typically cost between $250 and $600” depending on size and condition; a Washington state contract for government interceptors runs $516.20 flat for the first 100 gallons plus $5.09 per gallon above that, which is a useful upper anchor. Call (509) 352-0550 for a flat number on your device.
Calculator: when does your device hit 25%?
Is the trap big enough?
What not cleaning costs
| Provision | Exposure |
|---|---|
| Administrative fine (8.03A.0906) | up to $10,000 per violation per day |
| Civil penalty (8.03A.1001) | $1,000 to $10,000 per violation per day |
| Sewer cleaning or repair (8.03.5080.F) | billed to the owner |
| Overflow liability (8.03A.0213) | costs of any sewer overflow your discharge causes |
The fines page, with the section wording →
Plain-English guidance, not legal advice. Quotations are from Spokane County Code
Chapter 8.03 (Sewer Use) and 8.03A (Pretreatment), Municode version dated Sep 11, 2026, read 2026-10-08.
The City of Spokane (SMC 13.03A) and Spokane Valley (SVMC 22.160) publish their own FOG rules through
eCode360, which we could not read directly; where this site describes them it says so. Confirm current
requirements with the county’s FOG program at (509) 477-7579.