Cook County, IL
Plumbing permits and septic in unincorporated Cook County
Updated · Editorial team; not yet technically reviewed
Short answer
In unincorporated Cook County, the Department of Building and Zoning requires a plumbing permit to install, alter or repair plumbing fixtures and systems, including sewer and water systems. Septic work needs a private sewage disposal bond and Cook County Department of Public Health approval. Chicago and the suburbs issue their own permits.
What Cook County handles
A plumbing permit is required for installing, altering or repairing any plumbing fixtures or plumbing systems, including sewerage and water systems. [1]
Septic applications need a private sewerage disposal system bond, a recording fee, and the Health Department's sewage disposal approval number. [1]
Construction served by a septic field must have Cook County Department of Public Health approval of the system at submittal; plumbing-related trades include sewer, water, septic, well and lawn irrigation work. [2]
Where county rules apply
Unincorporated pockets sit between suburbs across the county. If your address isn't inside a village or city, the county's Building and Zoning department handles plumbing permits. Chicago has its own permits; see Chicago lead service lines and Chicago basement flooding.
Wells and septic
- Septic installation or replacement needs Public Health approval before the plumbing permit.
- Well work is a plumbing-related trade with its own registration.
- Lawn irrigation connections also fall under plumbing permits; see backflow testing.
City-specific guides in Cook County
Common questions
Does unincorporated Cook County require plumbing permits for repairs?
Yes; installing, altering or repairing plumbing fixtures or systems needs a permit.
Who approves septic systems in unincorporated Cook County?
The Cook County Department of Public Health.
What does a Cook County septic permit require?
A private sewage disposal bond, a recording fee, and the Health Department approval number.
Does Cook County issue permits inside Chicago?
No; Chicago and the suburbs issue their own.
Is lawn irrigation work permitted in unincorporated Cook County?
Yes; lawn irrigation is listed among plumbing-related trades.
Do sewer and water service lines need a Cook County permit?
Yes; sewerage and water systems are covered by the plumbing permit requirement.
Is well work regulated in unincorporated Cook County?
Well work is a plumbing-related trade under county registration.
How do I know if my address is unincorporated?
If it isn't inside a village or city, county rules apply.
When must septic approval be in hand?
At permit submittal for construction served by a septic field.
Who handles Cook County plumbing permit questions?
The Department of Building and Zoning's plumbing inspector.
Cities and services in Cook County
- Plumbing services in ChicagoChicago's plumbing story is dominated by lead. Lead water service lines went into Chicago homes into the mid-1980s, and the city now has hundreds of t…
- Water Line Repair in IllinoisIllinois' lead line law: inventories, notice before work, no partial replacements, and deadlines from 2042 to 2077 by system size.
- Plumbing in IllinoisStatewide code, licensing and climate for Illinois.
Sources (2)
- Cook County Department of Building and Zoning, Plumbing permit application · checked 2026-10-03
- Cook County Department of Building and Zoning, Permit tips and submission requirements · checked 2026-10-03