Spokane County sewer customers
Most of Spokane Valley, Liberty Lake’s county-served areas, Mead, and the unincorporated urban area are on county sewer, under County Code 8.03 and 8.03A: traps every 30 days, interceptors every 90, 25% rule, pumped dry, no additives, records three years. The full rule → Spokane Valley adopts its own development code chapter (SVMC 22.160) for FOG, which we have not read in full; the county program administers the sewer.
City of Spokane customers
The City of Spokane runs its own wastewater pretreatment program under Spokane Municipal Code 13.03A. The city’s code is published through a platform we could not read directly for this page, so we do not quote it. What we can say: the city’s program is built on the same federal pretreatment rules and the same state plumbing code, and in practice city inspectors expect the same things — a sized device, a cleaning schedule you can show, records, no additives. We service city kitchens on the county clock as a conservative default and document every visit the same way; if your city permit sets a different interval, tell us and we keep that one.
Both
Washington adopts the 2021 Uniform Plumbing Code (WAC 51-56-003), which is where device sizing comes from in both jurisdictions; the state sets no cleaning interval of its own. The Spokane Regional Health District licenses more than 2,500 permanent food establishments across the county — the kitchens all these rules exist for.
Not sure which you are?
Look at the sewer line on your utility bill, or tell us the address. We will tell you which code governs and schedule to it.