We have 257 parcels measured as septic in ZIP 99031 itself (Spokane County, Washington), out of 831 parcels in our records for this ZIP, of which 42 are recorded as on sewer.
| County | Land in this ZIP | Documents held | On septic (county) | On sewer (county) |
|---|---|---|---|---|
| Spokane County, Washington | 100% | 27 | 36,413 | 127,463 |
Land-area overlap is from the 2020 Census Bureau ZCTA5-to-county relationship file, not an estimate of ours. Parcel and document counts are rows we hold, not a survey of every property in the ZIP. Last verified 2026-09-01.
We have measured 257 parcels as septic in ZIP 99031 itself, out of 831 parcels in our records for this ZIP.
ZIP 99031 falls in Spokane County, Washington.