Most people think of water contamination as something that happens somewhere else — to communities near factories, to cities with aging infrastructure, to places they see on the news. The reality for rural households in Illinois and across the agricultural Midwest is different. The water under your feet has been absorbing what has been applied to, spilled on, and buried in the land above it for generations.
This post covers the primary contamination types in agricultural and rural Illinois, how to find out what is actually in your water, what it does to the body, and what to do about it.
HOW GROUNDWATER GETS CONTAMINATED
Groundwater — the water in aquifers that supplies private wells and contributes to municipal water systems — is not isolated from the surface. Rain and snowmelt carry surface contaminants downward through soil and into the water table. In central Illinois, the geology is particularly permissive. Much of the region sits over shallow, highly fractured limestone aquifers and sandy glacial deposits that allow relatively rapid movement of surface water — and surface contaminants — into groundwater.
Private wells draw directly from this groundwater with no treatment between the aquifer and your tap. Unlike municipal water systems, private wells are not regulated, not routinely tested, and not subject to federal drinking water standards. You are responsible for knowing what is in your well. Most people never test it.
PRIMARY CONTAMINANTS IN AGRICULTURAL ILLINOIS
Nitrates — The most widespread agricultural groundwater contaminant in Illinois. Nitrates come from nitrogen fertilizers applied to cropland, animal waste from livestock operations, and septic system effluent. The federal maximum contaminant level (MCL) is 10 mg/L, set primarily to protect against methemoglobinemia — “blue baby syndrome” — in infants under 6 months. Emerging research links nitrate exposure above the MCL to colorectal cancer, thyroid disruption, and adverse birth outcomes. If you are on a well in an agricultural area of Illinois, nitrate testing is not optional.
Atrazine — One of the most widely used herbicides in the United States, applied primarily to corn fields. Banned in the European Union. Detected in drinking water sources across the Midwest at levels that regularly exceed both federal limits and more protective health guidelines. Atrazine is an endocrine disruptor with documented effects on reproductive function, thyroid hormone signaling, and immune function. The EPA’s current MCL is 3 μg/L. EWG’s health guideline is 0.1 μg/L — 30 times more protective than the legal limit.
Glyphosate (Roundup) — The most widely used herbicide in the world. Detected in surface water, groundwater, rain, and air samples across agricultural regions. The EPA maintains it is not likely carcinogenic. The International Agency for Research on Cancer classified it as “probably carcinogenic to humans” in 2015. Multiple large legal judgments against Bayer/Monsanto have found that glyphosate-containing products caused cancer in plaintiffs. Glyphosate has also been documented to disrupt the gut microbiome and chelate minerals in food and in the gut. Testing requires specialized laboratory analysis — ask specifically for glyphosate when ordering a water test panel.
Arsenic — Occurs naturally in some Illinois geological formations and is also introduced through agricultural chemicals and industrial contamination. A known human carcinogen at elevated levels. The federal MCL is 10 μg/L; EWG’s health guideline is 0.004 μg/L, reflecting the carcinogenic risk at lower levels.
Lead — In drinking water, lead is primarily a plumbing issue — it leaches from lead pipes, lead solder, and brass fittings into water as it sits in the plumbing. Homes built before 1986 in Illinois are most likely to have lead plumbing components. There is no safe level of lead exposure for children. If your home was built before 1986, lead testing is not optional if children live there.
Industrial solvents and petroleum products — Leaking underground storage tanks, industrial facilities, and dry cleaners have contaminated groundwater in and around many Illinois communities. Volatile organic compounds (VOCs) including trichloroethylene (TCE), tetrachloroethylene (PCE), and benzene are detected in groundwater near these sites. These are known or probable carcinogens. The Illinois EPA maintains a database of known contaminated sites — check it if you are on a well near a former gas station, industrial facility, or dry cleaner.
FINDING OUT WHAT IS IN YOUR WATER
Municipal water: Your utility publishes an annual Consumer Confidence Report. EWG’s Tap Water Database (ewg.org/tapwater) aggregates this by zip code and is the most accessible starting point.
Private well: A basic potability test (bacteria, nitrates, pH) runs $50-100. A comprehensive agricultural panel adding pesticides, herbicides, and metals runs $150-300. A full VOC panel adds another $100-200. For a well in an agricultural area of Illinois, at minimum test for: coliform bacteria, nitrates, arsenic, lead, atrazine, and pH. Contact your county extension office or the Illinois Department of Public Health for testing guidance and subsidized testing programs. The University of Illinois Extension publishes guidance specific to Illinois well water contamination patterns. EWG’s Tap Water Database and the IEPA’s GIS mapping tools allow you to look at contamination history and known contaminated sites near your address.
WHAT FILTRATION ADDRESSES WHAT
Reverse osmosis addresses nitrates (80-90% reduction), arsenic (90-95%), atrazine and most pesticides (90%+), heavy metals including lead (95%+), PFAS, and many VOCs. The most broadly effective point-of-use system for agricultural and rural well water.
Activated carbon addresses atrazine and most organic pesticides and herbicides effectively. Does not adequately address nitrates, heavy metals, or arsenic.
UV treatment addresses biological contamination but does not address chemical contaminants.
For lead specifically: Flushing the tap for 30-60 seconds before drawing drinking water reduces lead from plumbing. Point-of-use RO or certified carbon block filters at the tap address lead in drinking water.
SUPPORTING YOUR BODY
Liver support: Milk thistle, dandelion root, burdock root, turmeric with black pepper — daily-use herbs for anyone with ongoing chemical exposure through water or environment. See the Herbal Remedies section for preparation details.
Kidney support: Nettle leaf tea daily. Adequate hydration with clean filtered water. Marshmallow root cold infusion for urinary tract support.
Gut support: Dietary fiber for binding and eliminating contaminants in bile. Fermented foods for microbiome support — particularly relevant given glyphosate’s documented effects on gut bacteria.
Mineral repletion: Glyphosate may deplete minerals through chelation. Adequate zinc, magnesium, manganese, and iron through whole-food sources. Sea vegetables for iodine. Green vegetables for magnesium. Pumpkin seeds for zinc.
Cilantro and chlorella: Both have traditional and emerging evidence for supporting heavy metal mobilization. Cilantro in quantity has been used in integrative medicine as a heavy metal mobilizer. Chlorella has documented binding affinity for heavy metals in the gut. Adjuncts only — the foundation is reducing exposure through filtration first.
WHERE TO START
Look up your address on EWG’s Tap Water Database. If on a well, contact your county extension office for testing guidance. Test before you filter — know what you have, then match the filtration to the contamination profile. If you have children under 6 or are pregnant, lead and nitrate testing comes first. Consider RO for drinking and cooking water as the broadest-spectrum solution for agricultural Illinois well water.
The land is generous in Illinois. The water is complicated. Test it.
Cross-reference: Know Your Water — PFAS | Know Your Water — Fluoride | Know Your Body | Herbal Remedies — Liver Support | Root Cellar — Water Protocols
FROM THE WASTELAND
Leaf Juice — Wasteland Survival Series, Book 1
The liver, kidney, and gut support herbs in this post have full preparation protocols in Leaf Juice — milk thistle, burdock, dandelion, nettle, all as teas, tinctures, and tonics.
Paperback | Kindle