According to a recent Chicago Tribune analysis, more than 8 of every 10 people in the state of Illinois live in a community where brain-damaging lead was found in the tap water of at least one home during the past six years. Indeed, tap water in dozens of Illinois homes had hundreds and even thousands of parts per billion of lead — the same level as investigators found in Flint, Michigan, where mismanagement of the public water system recently exposed children to the toxic metal. That can be cause for alarm by itself. But lead isn’t the only contaminant found in the water of Illinois residents. Take a look at what else can be found in our state’s water, compiled from various sources in and around the Chicago area.

Coliform Bacteria / E. coli

Coliforms are bacteria present in the digestive tracts of animals, including humans. Most coliforms are harmless, though some strains of E. coli can cause serious illness, even death. Other types of coliforms have been known to cause diarrhea, cramps, nausea, and headaches in otherwise-healthy people. (Note: Such impacts can be much more serious and even life-threatening for children, the elderly, and immune-compromised people.) Unfortunately, you cannot tell by the look, taste, or smell of the water if disease-causing organisms are in it, however you can get it tested (such as what we offer at Restore Water Solutions, with our free water quality analysis). 

Copper / Lead

Copper can get into your drinking water as it passes through your household plumbing system. Your body needs some copper to stay healthy, but too much can be harmful. Ingesting an excess amount of copper in food or water can cause vomiting, stomach cramps, nausea, diarrhea, liver damage, and kidney disease. Also, it’s dangerous for individuals with Wilson’s disease (a rare inherited disorder), as well as some babies may not able to get rid of extra copper easily. Drinking water with more than 1,300 micrograms of copper per liter can be a health risk.

As mentioned, exposure to lead is especially toxic to children and can cause serious and in many cases, irreversible damage to developing brains and nervous systems. Lead exposure has also been linked to miscarriages and stillbirths in pregnant women, fertility issues, cardiovascular and kidney effects, cognitive dysfunction, and high-blood pressure in otherwise healthy adults. Learn more about our Whole Home Water Filtration system, which can remove lead from your home water supply.

Disinfectants / Disinfectant By-Products

These days, many people know that common disinfectants such as chlorine and chloramine are used to treat water to eliminate water-borne transmission of diseases such as typhoid and paratyphoid fevers, cholera, salmonellosis, and shigellosis. Indeed, chlorination and chloramination are still the most widely used method for disinfecting water supplies in the United States. Chlorine levels up to 4 milligrams per liter are generally considered safe in drinking water. For chloramination, there were no have been no ill health effects from drinking water with chloramine levels of less than 50 milligrams per liter.

Disinfectant by-products are created as chlorine or chloramine reacts with water. Common by-products include:

  • Chloroform – CHCl3
  • Bromodichloromethane (BDCM) – CHCl2Br
  • Dibromochloromethane (DBCM) – CHClBr2
  • Bromoform 

Overexposure to such contaminants has been linked to cancer and may be also be related to reproductive impacts such as miscarriages and birth defects.

Inorganic Contaminants (Arsenic, Fluoride, and Perchlorate)

Inorganic contaminants such as arsenic, iron, chromium, and manganese commonly occur in nature and often end up in our surface and ground waters. Others are a result of manmade pollution such as perchlorate, while still more such as nitrates occur because of interactions between nature and pollution. Here are a few that have been found in water in Illinois:


Contrary to what most people think, arsenic is a naturally occurring component of the earth’s crust, and is widely distributed throughout the air, water, and land. According to the World Health Organization, arsenic is also used industrially as “an alloying agent, as well as in the processing of glass, pigments, textiles, paper, metal adhesives, wood preservatives and ammunition.” Inorganic arsenic is naturally present at high levels in the groundwater throughout the United States. It is very toxic. People can be exposed to high levels of inorganic arsenic through contaminated drinking water, food preparation, crop irrigation, or even smoking tobacco. A known carcinogen, repeated exposure can lead to cancers, developmental effects, and cardiovascular disease. 


According to the Centers for Disease Control, many research studies have proven the safety and benefits of fluoridated water, including better dental health. Drinking fluoridated water keeps teeth strong and reduces cavities (also called tooth decay) by about 25% in children and adults. By preventing cavities, community water fluoridation has been shown to save money both for families and for the US health care system. There are some risks to ingesting too much fluoride, though, in general it is not considered too harmful except in extreme cases.


Perchlorate is a chemical compound (most are commercially produced salts), primarily used as oxidizers for pyrotechnic devices, rocket fuel, or for other propellants – and even to control static electricity in food packaging. In large amounts, in can interfere with iodide uptake in the thyroid gland, which is a central control point for many hormonal responses. It has been detected in Illinois, as well as 25 other states and one territory. Repeated exposure to perchlorate can not only be harmful to the functioning of the thyroid gland but can also lead to developmental issues in fetuses and children.


Nitrates are compounds formed naturally when nitrogen combines with oxygen. Nitrates naturally occur in most surface water or groundwater, and it’s important to note that nitrogen is essential for all living things. But, high levels of nitrates in your drinking water can be dangerous to health, especially for infants and pregnant women. For example, exposure can lead to blue baby syndrome in infants, developmental effects, and cardiovascular disease. In extreme cases, blue baby syndrome can be severe and lead to death. Nitrates may be successfully removed from water using treatment processes such as ion exchange, distillation, and reverse osmosis.


We hope you found this helpful. This is, by no means, an exhaustive list of contaminants, but just a few of the more notable ones. Want to learn more? Contact us at Restore Water Systems to get your free water quality analysis, and find out more about what’s in your water!

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