Environmental Health records (including on-site sewage records) are available online. Anyone can access those records by searching our online records database. We recommend searching by the 12-digit tax parcel number. Sewage related records are typically marked with an “SWG”. An As-built or Record Drawing typically provides the best available information on system location. Sometimes a review of other sewage records are needed to make these determinations.


Note: Some older Onsite Sewage Systems may not have an as-built or any sewage records available. Of the 26,000 Onsite Sewage Systems in Mason County, about 13% do not have an Asbuilt/Record Drawing.

DID YOU KNOW? Environmental Health staff spent over 15 years combing through the county’s 60,000+ parcel files for sewage, drinking water, and other EH records. All records were reviewed and verified, then scanned to the online database. On top of scanning existing historic records, all new records being created were scanned as well. By having these records online and readily available to the public, records requests were reduced by over 75%. This work was paid for by several federal and state grant projects.

Today, our staff continues to scan all new records being created by environmental health staff. After a permit is approved or record created, it may take 2-4 weeks before it is available online, depending on current workloads and staffing. If you are having troubles finding online records, give us a call as 360-427-9670, extension 400. If you would still like to make a formal records request, click here .