About this list
- Agency
- Illinois EPA - Environmental Laboratory Accreditation Program (IL ELAP, chemistry) and Illinois Department of Public Health (IDPH, water microbiology)
- Format
- PDF x2 (IEPA chemistry list; IDPH microbiology list with methods per lab) + TNI LAMS drinking-water scope per chemistry lab, analyte-level
- Homeowner flag
- Not stated in the lists. IDPH marks each microbiology lab's 'Lab Type' (Commercial, Municipal or Health Department); that is not a statement about homeowners' samples.
Certified as of12/09/2025 (date in the file name; the PDF prints no date); TNI LAMS as fetched 2026-11-15
IEPA Accredited Laboratories (Primary Labs / Secondary Labs) - Laboratories Accredited for Chemical Analysis + TNI LAMS fields of accreditation (Drinking Water, accrediting body IL ELAP). Fetched 2026-11-15 (UTC).
Official sourceTesting your well in Illinois
How often to test
- Illinois EPA recommends testing for bacteria at least once a year and for nitrate every year, and always testing for nitrate before giving well water to an infant. [1]
- Illinois EPA and IDPH recommend a VOC test if you live in an urban or suburban area with a business, industry or gas station nearby. Rural wells that may be affected by leaking fuel tanks should also be tested for VOCs. [1]
Free testing
We found no statewide free testing program in Illinois. Ask your county health department whether it runs one.
Testing programs and help
- Illinois EPA says your local health department is the best place to start. Most local health departments can test for coliform bacteria and nitrate. [2]
- Certified labs also test well water and may be your only option for certain chemicals. Illinois EPA suggests asking your local health department which other tests you need and how often. [1]
- IDPH says sample bottles are available from local health departments. Where there is no local health department, contact the nearest IDPH regional office. [3]
Buying or selling a home
- IDPH recommends testing all new wells and wells that have been repaired. A new water supply should also be tested for nitrate. [3]
- Under the state Water Well Construction Code, when a new well is finished or an existing well is modified, the contractor must give the owner IDPH information on why and how to sample the well water. [4]
State lab and rules
- IDPH's laboratories in Carbondale, Chicago and Springfield are certified to test drinking water for total coliforms and E. coli. They accept water samples only from regional, county or city environmental health staff. [5]
- IDPH is the agency designated by U.S. EPA to certify laboratories that run microbiological tests on official water samples. [6]
Show the numbers
| Item | Value | Note |
|---|---|---|
| Zone 1 | 56 counties | |
| Zone 2 | 43 counties | |
| Zone 3 | 3 counties |
Radon in indoor air, not in water. EPA: Zone 1 = highest potential (average indoor radon may be above 4 pCi/L); Zone 2 = 2 to 4; Zone 3 = below 2. EPA says the map should not be used to decide whether an individual home needs testing. Source: U.S. EPA, Map of Radon Zones, county list (EPA 402/A-16/001, spreadsheet Sep 2025), accessed 2026-11-01.
Sources
- Illinois EPA, Private Well Users: Well Water Testing
- Illinois EPA, Private Well Users: Where to Get Help
- Illinois Department of Public Health, Well Sampling for Coliform & Nitrate (fact sheet)
- Illinois Department of Public Health, 77 Ill. Adm. Code 920 Water Well Construction Code, Section 920.100 (printer-friendly copy linked from IDPH's private water page)
- Illinois Department of Public Health, Lab Testing & Services: Environmental Testing
- Illinois Department of Public Health, Environmental Water Lab Certification
- U.S. EPA, Map of Radon Zones, county list (EPA 402/A-16/001, spreadsheet Sep 2025)
Loan test (FHA, VA, USDA) in Illinois
- VA. Test results are valid for 90 days from the date the local health authority certifies them, unless the local authority says otherwise. VA’s chapter names no list of contaminants: the water must meet the local health authority’s requirements, or EPA guidelines where it has none. Your lender may ask for specific tests.
- FHA. A well test is required in the situations FHA’s handbook lists, among others, and the report may not be more than 180 days old at disbursement.
- USDA. Guaranteed loans need a water quality test for a private well, done by the local health authority or a state-certified lab, and no more than 180 days old at closing.
Lenders can ask for more (extra tests, a particular lab, who takes the sample): ask your lender before you book. Federal rules as read on Nov 3, 2026 source 1 source 2 source 3. Full comparison: VA, FHA and USDA well water test requirements. Loan test kits sold by mail, with price and days to results: kits compared.
What Illinois labs say on their own websites
State lists say what a lab is certified for, not whether it takes your sample or what it costs. We read each lab’s own site; a second reader re-checked every fact below. 16 labs on this list are on our register so far; 4 say they take homeowner samples and 2 print a price.
| Lab | Bacteria (coliform / E. coli) | Nitrate | Arsenic | Lead | Basic well panel | Home sale / loan package | Turnaround |
|---|---|---|---|---|---|---|---|
| First Environmental Laboratories, Inc. Naperville, IL · You collect the sample with the lab's bottles | Total Coliform $75.00 source | Nitrate $13.00 source | – | Lead $40.00 source Lead in Drinking Water - Residential Sources Cost: $40 per sample source | Basic Package: Hardness, Nitrate, Nitrite, pH, Arsenic, Iron, Lead, Manganese, Sodium, Calcium, Magnesium, and Potassium $124.00 source | – | we will have results for you in approximately two weeks |
| Will County Health Dept. - Environ. Health Lab. Joliet, IL · You collect the sample with the lab's bottles | Routine Bacterial Screens $20.00 source Bacterial Screen with Count $25.00 source | Nitrate Analysis $18.00 source | – | – | – | – | – |
Say they take homeowner samples: First Environmental Laboratories, Inc., Pace Analytical Services, LLC – McHenry, Illinois, Test, Inc., Will County Health Dept. - Environ. Health Lab..
Prices exactly as each lab prints them, read 14 Nov 2026 to 15 Nov 2026; re-checked every 90 days. Labs not shown have not been read yet or print nothing for homeowners. Confirm price and turnaround with the lab.
Labs by contaminant
Labs on the Illinois list for one test, with homeowner-accepting labs first.
Well water by county
Private-well population (USGS, 2015), arsenic estimate, radon zone and nearby labs for each county with at least 1,000 people on private wells, largest first.
Will County140,315 on wellsLake County86,970 on wellsDuPage County72,636 on wellsSt. Clair County68,519 on wellsMcHenry County65,640 on wellsKane County54,498 on wellsWinnebago County39,983 on wellsSangamon County32,420 on wellsMadison County26,905 on wellsKendall County23,274 on wellsWilliamson County23,081 on wellsKankakee County21,962 on wellsOgle County19,549 on wellsChampaign County19,061 on wellsPeoria County19,037 on wellsVermilion County19,002 on wellsWhiteside County18,869 on wellsLaSalle County18,766 on wellsMcLean County14,581 on wellsWoodford County14,450 on wellsStephenson County13,015 on wellsBoone County12,254 on wellsEffingham County11,302 on wellsHenry County11,059 on wellsGrundy County10,790 on wellsLivingston County10,545 on wellsShelby County9,207 on wellsTazewell County8,983 on wellsIroquois County8,825 on wellsMonroe County8,549 on wellsLogan County8,349 on wellsBureau County8,069 on wellsFulton County7,708 on wellsLee County7,635 on wellsDeKalb County7,479 on wellsJo Daviess County7,297 on wellsMacon County6,795 on wellsCumberland County6,335 on wellsMercer County6,239 on wellsEdgar County6,156 on wellsKnox County6,094 on wellsHancock County6,043 on wellsMason County6,007 on wellsCarroll County5,830 on wellsRandolph County5,822 on wellsWashington County5,575 on wellsCook County5,239 on wellsDe Witt County5,213 on wellsJackson County5,121 on wellsLawrence County5,064 on wellsWarren County4,975 on wellsJohnson County4,874 on wellsJefferson County4,851 on wellsUnion County4,628 on wellsPiatt County4,557 on wellsDouglas County4,544 on wellsPerry County4,327 on wellsFayette County4,158 on wellsMcDonough County4,060 on wellsMontgomery County3,920 on wellsSaline County3,778 on wellsMoultrie County3,682 on wellsCrawford County3,429 on wellsClay County3,379 on wellsFord County3,349 on wellsAdams County3,288 on wellsChristian County3,282 on wellsColes County3,258 on wellsRichland County3,252 on wellsMarshall County3,169 on wellsBrown County2,790 on wellsClinton County2,743 on wellsWhite County2,717 on wellsJasper County2,669 on wellsCass County2,665 on wellsPulaski County2,488 on wellsStark County2,212 on wellsMenard County2,122 on wellsMorgan County1,915 on wellsRock Island County1,913 on wellsGreene County1,861 on wellsPutnam County1,711 on wellsFranklin County1,663 on wellsWabash County1,537 on wellsJersey County1,200 on wellsMarion County1,102 on wellsBond County1,022 on wells