Tacoma, WA septic or sewer: septic records and sewer mains
7,334 of the 99,543 lots in Tacoma (7%) have septic records on file with the Tacoma-Pierce County Health Department. 23,165 lots are inside a Pierce County sewer service area, and 90,503 are within 300 feet of a sewer main on the county's sewer map.
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 Tacoma on septic or sewer?
Both. 7,334 lots have septic records on file, and 23,165 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 sewer main and who owns it, 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 November 7, 2026.