Key Laboratory Services
IL certified
Homeowner samples
- Coliform Bacteria
Illinois county well guide
Well Water in DeWitt County, IL: Testing, Contractors and Rules
About 2,085 households in DeWitt County, 32% of the county, rely on a private well. Nobody tests that water unless the owner does.
of households on a private well
Share on wells, county vs state
3licensed contractors serve the county
21 mito the nearest certified lab, Key Laboratory Services
Nostatewide test required when a home is sold
About one in 3 households in DeWitt County relies on a private well, around 2,085 homes. Outside the towns with public water, wells are the norm here.
Local rules for wells in DeWitt County
The rules that apply in DeWitt County are set at the state level in Illinois. New wells must be tested before use, and nothing is required at sale. Some counties and townships add permits or setbacks of their own, so check locally before drilling. The state's own recommendations are below.
At a glance
Water test for a new wellRequired
A permit from the county health department (or IDPH where the county has no delegated program) is required before a private well is drilled, the well must be built by an IDPH licensed water well contractor to the Illinois Water Well Construction Code (steel or approved plastic casing, grout, the setbacks from septic systems and other sources, a sanitary well cap above grade), and the contractor files a well construction report with IDPH. Under the code the new well is disinfected and a bacteria sample is collected, in most counties by the health department at the final inspection, before the well is approved for use; the health department's sign-off is what the building department wants before occupancy.
Water test when a home is soldNot required statewide
No statewide requirement. The Illinois Residential Real Property Disclosure Report asks the seller about the water supply and any known defects, and FHA, VA and USDA loans require a bacteria, nitrate and lead sample from a certified lab before closing. A few counties run point-of-sale well and septic inspection programs under local ordinance, so ask the county health department.
What the state recommends
IDPH recommends testing a private well every year for coliform bacteria and nitrate, after any repair or flooding, and whenever the taste, color or smell changes; a chemistry panel (arsenic, iron, manganese, hardness, chloride, sulfate) when the well is new or every few years; and, depending on the aquifer, radium and barium for deep sandstone wells in northern Illinois, arsenic for wells in the Mahomet and other glacial aquifers of central Illinois, and pesticides and nitrate for shallow wells in farm country. County health department labs run the bacteria test cheaply, and the IDPH state lab tests samples submitted through the county.
Free or low-cost testingAvailable
No statewide free program. Most county health departments sell a bacteria (and often nitrate) sample kit for a small fee and explain the result, and the IDPH Division of Laboratories runs the bacteria test for counties without their own lab. The Illinois State Water Survey and university extension programs run periodic free nitrate and arsenic screening clinics in farm counties.
Getting your water tested near DeWitt County
The nearest certified lab is Key Laboratory Services in Monticello, about 21 miles from the county center, and it accepts samples from homeowners. Mail-in kits fill the gap for anything it does not run.
1 certified labs within 40 miles
Licensed well contractors serving DeWitt County
Licensed help in DeWitt County includes Cody W Parrott and James G Layten and 1 other. Every listing was matched to the Illinois license list; the "verify" link on each profile opens the state lookup.
3 licensed contractors
Cody W Parrott
Verified license
License 102-004587 Active
- Geothermal
- Pump Installation
- Pump Repair
- Well Abandonment
- Well Drilling
- Well Repair
James G Layten
Verified license
License 102-002243 Active
- Geothermal
- Pump Installation
- Pump Repair
- Well Abandonment
- Well Drilling
- Well Repair
Mark J Layten and Sarah B Gassaway
Verified license
License 092-008291, 101-005106, 102-004793 Active
- Geothermal
- Pump Installation
- Pump Repair
- Well Abandonment
- Well Drilling
- Well Repair
Well depth and water chemistry
Well depth and water chemistry in DeWitt County follow the rock underneath it. Typical wells here run 90 to 280 feet; the median of 382 private water wells on the ISGS ILWATER map drilled since 2000 is 190 feet. Contaminants worth testing for in this part of Illinois include arsenic (naturally occurring in the glacial sand and gravel aquifers of central and northeastern illinois, including the mahomet aquifer, where roughly one well in ten is over the standard), iron and manganese (nearly universal in glacial aquifers).
Typical well depth
90 to 280 feet; the median of 382 private water wells on the ISGS ILWATER map drilled since 2000 is 190 feet
Contaminants to test for
- Arsenic (naturally occurring in the glacial sand and gravel aquifers of central and northeastern Illinois
- Including the Mahomet aquifer
- Where roughly one well in ten is over the standard)
- Iron and manganese (nearly universal in glacial aquifers)
- Hardness (very hard water statewide)
- Radium and barium (the deep Cambrian-Ordovician sandstone aquifer of northern Illinois)
- Coliform bacteria (old large-diameter bored and dug wells
- Common in southern Illinois)
- Nitrate and atrazine (shallow wells in corn and soybean country)
- Chloride and sodium (road salt in the Chicago collar counties
- And natural brine in deep wells)
- Hydrogen sulfide and methane (deep wells in the south and the coal counties)
- Fluoride (locally high in deep aquifers)
Neighboring counties: Piatt County, Macon County, McLean County, Logan County.
What well work costs in DeWitt County
Basic bacteria and nitrate test$25 to $75lab fee, homeowner sample
Full panel lab test$150 to $400metals, VOCs, radiologicals
Well inspection$250 to $550flow, pressure, visual, water test
Submersible pump replacement$1,200 to $4,500parts and labor
Pressure tank replacement$400 to $1,200installed
Whole-house treatment system$800 to $6,000softener, iron filter, UV, RO
New well drilled$5,500 to $25,000about $25 to $65 per foot
Shock chlorination$80 to $300or about $20 as a DIY job
National ranges from published 2025 to 2026 contractor pricing. Local quotes vary with depth, access and materials.
Questions DeWitt County well owners ask
How many homes in DeWitt County are on a well?
About 2,085, or 32% of households, based on Census housing data and state well surveys. The share is highest outside the towns with public water.
Where is the closest certified lab to DeWitt County?
Key Laboratory Services in Monticello, about 21 miles away. It accepts homeowner samples.
Do I need a permit to drill a well in DeWitt County?
A permit from the county health department (or IDPH where the county has no delegated program) is required before a private well is drilled, the well must be built by an IDPH licensed water well contractor to the Illinois Water Well Construction Code (steel or approved plastic casing, grout, the setbacks from septic systems and other sources, a sanitary well cap above grade), and the contractor files a well construction report with IDPH. Under the code the new well is disinfected and a bacteria sample is collected, in most counties by the health department at the final inspection, before the well is approved for use; the health department's sign-off is what the building department wants before occupancy.
What does a well test cost near DeWitt County?
A bacteria and nitrate test runs $25 to $75 at most certified labs; a full panel with metals is $150 to $400. Mail-in kits cost about the same as walking in.