Arsenic in Illinois well water

In Illinois, 10% of 5,098 tested private well samples exceeded the EPA limit for arsenic (10 ug/L).

Arsenic occurs naturally in New England bedrock and dissolves into well water. Long-term exposure raises the risk of bladder, lung and skin cancers, and is linked to heart disease and lower IQ in children. It has no taste or smell, so testing is the only way to know.

Check your arsenic number

Type the value from your lab report. It is compared to the EPA limit, the same way the full interpretation does it.

Test your Illinois well for arsenic

Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.

Order the Tap Score well water test kit, from $209 Already tested? Upload the report

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Systems that remove arsenic

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For arsenic

Under-sink reverse osmosis system

under-sink or countertop, about $300

Look for NSF/ANSI 58 certification listing the contaminant you need removed.

For arsenic

Whole-house arsenic and uranium filter

whole-house, at the point of entry, about $2,500

Adsorptive iron-based media; sized to your well yield.

For arsenic

Aquasana SmartFlow reverse osmosis

under-sink or countertop, about $225

Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.

Rather have it installed and sized for your well? Book a free in-home water test with a licensed local company.

Where to get a well tested for arsenic in Illinois: certified labs, state programs and prices.

By county, from individual samples

Public monitoring samples against the EPA limit (10 ug/L); counties with at least 30 samples.

County	Above EPA limit	Samples	Detected	Median	Highest
De Witt	72%	92	91%	26	94 ug/L
Macon	69%	49	86%	21	128 ug/L
Bureau	44%	81	69%	7.7	61 ug/L
Pulaski	43%	35	49%	0	27 ug/L
McLean	40%	82	67%	4.5	107 ug/L
Piatt	32%	56	82%	3.5	58 ug/L
Mason	27%	56	71%	2.5	27 ug/L
Tazewell	25%	108	50%	0.09	55 ug/L
Iroquois	22%	59	49%	0	52 ug/L
Woodford	19%	37	65%	2	32 ug/L
Whiteside	14%	50	52%	1	20 ug/L
Logan	13%	39	38%	0	42 ug/L
Champaign	11%	148	74%	2	93 ug/L
Vermilion	11%	53	81%	1	22 ug/L
DeKalb	11%	53	62%	2	15 ug/L

Chicago, Cook County14% of 59
Rantoul township, Champaign County6% of 31
Rockford township, Winnebago County3% of 96
Milton township, DuPage County3% of 33
Algonquin township, McHenry County2% of 83
Danville township, Vermilion County0% of 32
Dundee township, Kane County0% of 36
Chouteau township, Madison County0% of 38
Elk Grove township, Cook County0% of 68
Downers Grove township, DuPage County0% of 62
Joliet township, Will County0% of 41
Bloomingdale township, DuPage County0% of 30
Bethel township, McDonough County0% of 31
Nunda township, McHenry County0% of 47
Wood River township, Madison County0% of 35
Collinsville township, Madison County0% of 31
Wheeling township, Cook County0% of 86
York township, DuPage County0% of 86
Homer township, Will County0% of 33
Bloom township, Cook County0% of 46

Sources

Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. arsenic counts and shares are listed on each county and town page with their sources.

Analysis: Arsenic in private wells, state by state, from the same public records.