Chicago’s tap water is considered safe to drink by both the Chicago Department of Water Management and the Environmental Protection Agency, and testing shows contaminant levels to be within allowable limit.
However, the pipes running in many homes may leach dangerous levels of lead into your water.
It’s a good idea to be informed about lead and other possible concerns in order to make the best decisions for yourself and family regarding your water quality.
Chicago’s water quality report indicates the presence of several substances, including lead, barium, copper, nitrates, coliform bacteria, and more, but all were found to be within the allowable limit.
Lead Could Be a Concern in Chicago Tap Water
Lead levels were found to be 9.1 parts per billion (ppb) at the highest test, below the 15 ppb recommended limit. Lead in water results from household plumbing corrosion and natural deposits.
While the levels discovered are below the allowable limit, there is no level of lead exposure that is considered safe, according to the Environmental Protection Agency and the Center for Disease Control and Prevention.
Lead is especially a concern for young children since 40-60% of an infant’s lead exposure comes from their drinking water. Parents are advised to use filters if drinking tap water at home and also make sure that daycares and schools their children attend are also filtering their water if tests have shown lead to be an issue at those locations.
The city of Chicago is working to address the issue of lead pipes in aging water system, and in the meantime, corrosion control chemicals are being added to water in an effort to minimize the levels of lead.
Lead water contamination was the main cause of the popular flint water crisis in flint, Michigan.
Barium’s highest level detected was 0.0201 parts per million (ppm) with 2 ppm being the allowable limit. Barium comes from the discharge of drilling wastes and metal refineries as well as natural deposits.
Copper was found at a maximum level of 0.091 ppm with 1.3 ppm being allowed limit. Copper can get into water from corrosion of household plumbing, wood preservatives, and natural deposits.
Nitrates were found at a maximum level of .42 ppm while 10 ppm is considered safe. These come into water from runoff of fertilizer as well as leaching from septic tanks and natural deposits.
Coliform bacteria was detected at a highest rate of 0.2% with up to 5% considered safe. The source of coliform in water is animal or human waste.
Also measured in Chicago’s water were TTHMs and HAA5, which are by-products of water disinfection, as well as chlorine and fluoride. These substances are all added to water during treatment process.
Does Chicago Have Hard Water?
Chicago’s tap water is considered to be hard. The hardness is measured at 148 ppm, which is well into the hard range but is still lower than the Illinois state average of 200 ppm.
Chicago’s tap water comes from Lake Michigan. Water from the lake enters the intake crib at a depth of 20-30 feet before going through a treatment process prior to entering the public water supply.
Chicago’s tap water goes through a multi-step treatment process before it reaches a tap. This process includes:
- Passing through eight screens to filter out debris
- First chemical treatment
- Flocculation process to clump together sediment
- Settling basins to allow sediment to settle out of the water
- Filtration through sand and gravel
- Final chemical application
Chemicals used to treat tap water in Chicago include:
- Chlorine – disinfects
- Aluminum sulfate – coagulates impurities
- Blended polyphosphate – coats pipes to minimize lead leaching
The amount of chemical used to treat Chicago water is approximately 15 ppm or, in other words, around a teaspoon per 100 gallons of water.
While official tests have shown Chicago’s water to be clean, it is not likely to be the cleanest water in the country due to the network of pipes that deliver water to homes.
A 2018 drinking water analysis by Chicago Tribune looked at samples of tap water from 2,797 homes and found that 30 percent of those samples contained concentration of lead above 5 ppb, which is the highest level the U.S. Food & Drug Administration will allow in bottled water.
Furthermore, some level of lead was found in almost 70 percent of tap water samples, and while the EPA limit for lead in water is 15 ppb, there is no proven threshold for what is considered “safe” to drink.
Aging lead pipes could be a contributing factor to a higher lead level in water out of the tap than the water at the testing sites. Until 1986, Chicago required that service pipes running from mains under the streets into homes be lead pipes.
That practice was banned by Congress in 1986, but many miles of these pipes still exist and are leaching lead into water. The additives put in water may help the problem, but they are, unfortunately, not eliminating it completely.
Many people drink tap water in Chicago, though around 20% of the population relies mainly on bottled water to drink. It isn’t known how many households choose to filter their tap water before drinking it.
If you are concerned about lead in your tap water, the EPA issued advice to Chicago residents regarding how they can minimize the levels of lead in their drinking water.
Safety concerns aside, the water in Chicago tastes great for most of the year, though, during the hotter months, algae can cause a distasteful “rotting moss” flavor. While the taste is unappealing, the algae is harmless.