50 of the 3,028 lots in Steilacoom (2%) have septic records on file with the Tacoma-Pierce County Health Department. 280 lots are inside a Pierce County sewer service area, and 2,670 are within 300 feet of a county sewer main.
County sewer maps do not show sewers run by cities, so a lot inside a city may be on sewer even when no county main is nearby.
Septic records include permits, designs and inspections; older ones are on microfilm and are found by parcel number.
Questions
Is Steilacoom on septic or sewer?
Both. 50 lots have septic records on file, and 280 are inside a county sewer service area. It varies lot by lot.
How do I find out if a house is on septic?
Search its address on Colvos Parcel: the report lists any septic records for the lot, the nearest county sewer main and the sewer service area, with links to the originals.
From the Pierce County Assessor-Treasurer, the county's zoning, sewer, hazard and growth-area maps, and the Tacoma-Pierce County Health Department. Records as of October 2, 2026.