Illinois Septic & Well Water Rules

In Illinois, the Illinois Department of Public Health (IDPH) regulates private sewage disposal systems and licenses septic installers and pumpers. Many local health departments review septic plans and offer well water testing.

Official lookups

Septic rules & permits

Illinois septic systems are governed by the Private Sewage Disposal Licensing Act (225 ILCS 225) and the Private Sewage Disposal Code (77 Ill. Adm. Code 905).
IDPH regulates systems with no surface discharge (such as septic tanks and seepage fields) and those discharging up to 1,500 gallons per day (such as sand filters and aerobic units), and reviews plans before construction.
Under the Act, no new private sewage system may be installed until plans are reviewed and approval is issued. About 90 local health agencies also review construction plans, so start with your county health department.

Licensed installers and pumpers

Anyone who installs, repairs or maintains a septic system for someone else must be licensed by IDPH as a Private Sewage System Installation Contractor. Anyone who pumps or hauls septage must be licensed as a Pumping Contractor.
A homeowner who owns and occupies a single-family home may work on their own system without a license, but must still follow the code.
Licenses expire December 31 each year, so verify a contractor's license is current using the IDPH lookup below.

Inspection when you sell

We did not find a statewide septic inspection-at-sale requirement on IDPH's site. Some counties or municipalities may have their own rules, so check with your local health department before listing or buying.

Private well testing

IDPH and Illinois EPA recommend testing private wells every year for coliform bacteria and nitrate. Most local health departments can do this testing and provide sample bottles.
Test new, modified or repaired wells before use. Samples must reach the lab within 30 hours of collection.
Nitrate above 10 mg/L (as nitrogen) should never be given to infants under 6 months. Boiling does not remove nitrate; it concentrates it.
Illinois EPA also suggests considering tests for VOCs (near fuel or industry) and radium (mainly in northern Illinois). Certified labs may be the only option for these.

Frequently asked questions

Do septic pumpers need a license in Illinois?

Yes. Under 225 ILCS 225, anyone pumping or hauling septage for others must hold an IDPH Private Sewage Disposal System Pumping Contractor license.

Where can I test my well water in Illinois?

Most local health departments test for coliform bacteria and nitrate and provide sample bottles. Certified labs handle other tests.

How often should I test my well in Illinois?

IDPH and Illinois EPA recommend coliform and nitrate testing every year.

Sources

Last checked: October 21, 2026