Building or buying land in Colorado?
Before a septic permit comes a soil evaluation — and every county runs it differently. See your county's pit and perc rules and the season that applies, then get a qualified tester out early.
- 4 Colorado counties covered
- Every rule linked to the county's own regulation
- Verified July 2026
How it works
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Look up your county
Pit specs, perc procedures, seasonal windows, and fees differ by county. Start with where the land sits.
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See what the test really is
In most counties the 'perc test' is now a soil profile pit evaluation — see exactly what yours requires, with the regulation linked.
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Request a soil evaluation
Send your details to the site operator for review; no engineer or tester match or response is guaranteed.
Why land deals and builds get stuck here
The term everyone searches — 'perc test' — is no longer what most Colorado counties actually require, and outdated advice costs real money at permit time.
- Mountain counties have short testing seasons. Summit County generally issues no septic permits from October through May — miss the window and the build waits for the thaw.
- A poor evaluation result rarely means unbuildable — but the engineered-system path is county-specific and nobody explains it before you're under contract.
Start with the rules
Find your county
Rules differ by county. Find yours for the exact requirement, fees, and inspectors: