Bolthole Index

Bolthole Index county-legal census · checked 2026-10-10

Septic permits in Illinois

Septic permitting in Illinois is mixed: 74 counties use county health departments, 2 go through a state agency, and 26 through regional districts.Every entry below names the approving authority for that county, cited to the authority’s own page.

Septic rules change and some cities run their own programs — treat this as a verified starting point, not legal advice. All states → Illinois water rights & wells → Full Illinois profile →

102 counties · mixed — varies by county · permit status scouted for 102

Keep exploring

Every county here has a full profile — its index score, water, land prices, and the rest of its building rules. See the Illinois state page for all counties ranked, or the national septic guide.

Off-grid gear

Before the Illinois septic office sees a parcel, you can test it yourself. What we'd bring:

These are affiliate links — we may earn a commission, at no cost to you. As an Amazon Associate, Bolthole Index earns from qualifying purchases.

General guidance, not legal advice. Off-grid, building, and land-use rules are often set at the county level and change often. Verify with your county and state before acting. Data reviewed 2026-06-26.