ZIP 99115 falls in Douglas County, Washington, where we hold 5,222 parcels measured as septic county-wide and 8,831 on sewer. We do not have a per-ZIP parcel count for this county, so this is the county total, not a count specific to ZIP 99115.
ZCTA 99115 is not entirely inside one county. Land-area share is from the 2020 Census ZCTA-to-county relationship file.
| County | Land in this ZIP | Documents held | On septic (county) | On sewer (county) |
|---|---|---|---|---|
| Douglas County, Washington | 70% | 63 | 5,222 | 8,831 |
| Grant County, Washington | 30% | 15,176 | 14,575 | 16,431 |
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 hold 5,222 parcels measured as septic for Douglas County, Washington as a whole, not broken out by ZIP.
ZIP 99115 spans 2 counties: Douglas County, Washington, Grant County, Washington.