Boulder County: septic rules when you sell
Property Transfer Certificate (OWTS)
Selling a Boulder County property with plumbing on a septic system requires a Property Transfer Certificate: a NAWT- or NSF-certified inspector inspects the system, it must pass, and the report plus application go to Boulder County Public Health before closing. The fee is $500, processing can take up to ten business days, and systems given final county approval under five years ago are exempt.
County fee $500 for a Property Transfer Certificate.
Inspector requirement Inspection must be performed by a NAWT- or NSF-certified inspector who personally conducted the inspection (per the county's property-transfer instructions/report form).
When to apply Before closing; BCPH may take up to ten business days to process and issue the certificate, so submit with time to spare.
| Inspection at sale | Required for all dwellings/structures with plumbing at the time of sale or purchase; the system must pass and the report + application submitted to BCPH prior to closing. |
|---|---|
| County fee | $500 for a Property Transfer Certificate. |
| Inspector requirement | Inspection must be performed by a NAWT- or NSF-certified inspector who personally conducted the inspection (per the county's property-transfer instructions/report form). source ↗ |
| When to apply | Before closing; BCPH may take up to ten business days to process and issue the certificate, so submit with time to spare. |
| Validity | Not stated on the property-transfer page (certificate is tied to the transaction). |
| If the system fails | Three paths: pass inspection before closing; permit and complete repairs before closing; or sign an Agreement to Repair (365-day deadline to repair, or 2-year deadline to connect to sewer). |
| Exemptions | Not required if the system was installed and given final BCPH approval less than 5 years before closing; also spouse-only ownership changes, joint-ownership changes with the original owner/spouse, buildings being demolished/unoccupied after transfer, transfer to a same-name trust, foreclosure/forfeiture transfers, an existing BCPH repair agreement, connecting to municipal sewer within 2 years (with agreement), and community/management-district plans with written BCPH approval. |
Details to confirm with the county
We couldn't confirm the following from Boulder County's official pages. Check these with the county before you rely on them:
- Winter/snow inspection rule not addressed on the property-transfer page (the OWTS instructions note soil test holes must be free of snow, but no transfer-specific winter/spring-inspection agreement is stated).
- Certificate validity period not stated on official transfer page.
Verified July 2026 · Source: Boulder County Public Health — OWTS Property Transfer (SepticSmart)