Select a city below to view local well water testing services in your area. Each city page lists providers offering lab testing, field sampling, or mail-in well water tests.
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Illinois's landscape-from the Chicago suburbs to the central prairies and the rural downstate regions-includes many communities that rely on private wells for drinking water. While municipal water serves most of the population, private wells remain common in rural areas and smaller towns.
Illinois does not have a statewide law requiring private well water testing for contaminants. Testing is recommended by health officials but remains voluntary for most private well owners. This recommendation-based approach puts the responsibility on homeowners to make informed decisions about their water quality.
County health departments throughout Illinois play an important role in well water safety. They commonly offer sampling services, provide guidance on what to test for, and can direct you to certified laboratories. While requirements are typically driven by local ordinances, lender requirements, or personal initiative rather than state mandates, the support infrastructure for testing is well-established.
Illinois does not have a statewide law requiring private well water testing for contaminants, including at the time of home sale. The state's approach is recommendation-based: testing is advised but not mandated for routine ownership or property transactions.
County health departments may have local ordinances or programs that encourage or facilitate testing, but mandatory testing requirements are typically contract-driven (from your real estate transaction) or lender-driven rather than stemming from state law.
Mortgage lenders-particularly for FHA, VA, and USDA loans-frequently require water quality documentation as a condition of financing. Many buyers also request testing as part of their home inspection process. So while Illinois law doesn't require testing, practical reality often includes it.
Illinois county health departments commonly offer sampling services and can collect samples upon request. This makes testing accessible even in areas without nearby private labs. Check with your local county health department to understand what services and guidance are available in your area.
The baseline testing recommended everywhere applies in Illinois: total coliform bacteria and E. coli to check sanitary integrity, plus nitrates which pose health risks to infants and pregnant women. Annual testing for these parameters follows national public health recommendations.
Illinois's agricultural landscape-particularly in central and southern parts of the state-means nitrate contamination is a genuine concern. Fertilizers and livestock operations can contribute to elevated nitrate levels in groundwater. If you're in an agricultural area, nitrate testing is especially important.
Arsenic occurs naturally in some Illinois aquifers, and testing is recommended to know if it's present in your water. Some areas may also have naturally occurring radium or other radionuclides. Your local health department can advise on contaminants of concern specific to your area.
If you have older plumbing, lead testing is prudent-though lead typically comes from pipes and fixtures rather than the well itself. A first-draw sample can identify whether household plumbing is contributing lead to your drinking water.
Every year
For new properties and every 3-5 years thereafter
Based on location and circumstances
Well water testing costs in Illinois depend on what you're testing for and which provider you use. Basic bacteria and nitrate tests are generally affordable. Adding metals, radionuclides, or comprehensive panels increases the cost.
Illinois county health departments often provide sampling services at reasonable rates. Some offer testing directly; others collect samples and send them to certified labs. This can be a cost-effective option compared to private labs, and ensures proper sample handling.
Turnaround time follows typical patterns: bacteria results within a few days (samples are time-sensitive and must reach the lab within 24-30 hours), chemical tests for nitrates and metals within 5-10 business days. If you're testing for a real estate closing, factor in adequate time for the complete process.
For urgent needs, some labs offer rush processing for an additional fee. Ask about expedited options if you're working against a deadline.
Illinois well owners can choose from certified laboratories, county health department programs, sampling services, and mail-in test kit providers. For accurate, defensible results-especially for real estate transactions-use certified labs that follow standardized methods.
County health departments are often the best starting point in Illinois. They commonly offer sampling services, provide proper containers and instructions, and can advise on what to test for based on local conditions. Many counties have well-established environmental health programs.
If you're near the Chicago metro area, you'll have many private lab options. In more rural parts of the state, county health department services or mail-in testing may be more practical. Make sure any mail-in service can handle time-sensitive bacteria samples properly.
Treatment companies may offer testing, sometimes at reduced cost. While convenient for screening, remember their primary business is selling treatment equipment. Independent verification is wise before investing in expensive treatment systems based solely on a treatment company's test results.
Quick answers to common questions about testing well water in Illinois, from requirements to finding local services.