Water FAQs

Where does our water come from?
Is our tap water safe?
Why does my water get milky white?
How can I prevent my water service or pipes from freezing during the winter months?
Who is responsible for the repair costs of the service line?
I am going to be moving into a house. How do I know who is my water utility?
Why are there water restrictions?
Do water filters work and should I use one?
Do I need to treat the water before I use it for my fish?
Why does my water sometimes smell or taste like chlorine?
Does the water contain fluoride?
How hard is my water and should I use a water softener?
Do I have radon in the water?
How can I have my water tested?
What is that black stuff at the bottom and sides of the toilet?
What is this pink residue in my bathroom?

  • Where does our water come from?
    The DuPage Water Commission’s water comes from Lake Michigan, the largest freshwater lake in the United States and the fifth largest lake in the world. The Commission purchases the water from the Chicago Water Department. Chicago’s Jardine Water Purification Plant treats the water that the Commission purchases. The Jardine Water Purification Plant is the largest potable water filtration plant in the world with a capacity of 1.4 billion gallons per day.
  • Is our tap water safe?
    The water supplied to your water utility meets or exceeds every State and Federal regulations for drinking water. Annually people paying a water bill are notified of their water quality by their water utility.
  • Why does my water get milky white?
    Milky white water, also commonly described as cloudy, hazy, soapy, or foamy, is almost always caused by air in the water. One of the many properties of water is its ability to dissolve gases-including air. Sometimes the air comes back out of the water in the form of many tiny bubbles; this gives the water a milky white appearance. To see if the white color in the water is due to air, fill a clear glass with water and set it on the counter. Observe the glass of water for 2 or 3 minutes. If the white color is due to air, the water will begin to clear at the bottom of the glass first and then gradually will clear all the way to the top. This is a natural phenomenon and is completely normal; the water is safe to use. This situation can happen when the water gets cold, or whenever the water has been turned off for repairs. Cold water holds more dissolved air than warm water. In the winter and spring, the water is cold and contains a relatively high level of dissolved air. As the water moves through the water mains in the street and the pipes in your house, it begins to warm up and lose some of its ability to keep the air dissolved. However, because the water is under pressure in the pipes, the air remains in the water. When you relieve the pressure by opening the faucet and filling your glass with water, the air is now free to escape from the water, giving it a milky appearance for a few minutes. Another way for this milky white water to form is after your water utility has worked on a water main or you have had work done on your plumbing. When the water is shut off, air can get into the water main or your pipes. When the water pressure is restored, some of that air dissolves into the water. When you again relieve the pressure by opening the faucet and filling you glass with water, the air is now free to escape from the water thus giving it a milky white appearance for a few minutes. If your water is cloudy/milky and does not clear in a glass after 5 minutes, your should call your water utility.
  • How can I prevent my water service or pipes from freezing during the winter months?
    To prevent your service or the pipes within your home from freezing under very cold conditions, you can take a couple of precautions:If pipes or facilities are located against exterior walls, make sure that they are exposed to the warmer air of the house. For example, if your kitchen sink is located against an outside wall of your house, open the cabinet doors to permit the circulation of warmer air around the pipes.Turn on one of the faucets in your house to a low trickle to insure that there is a constant motion of water within your service. (Please do not take this step except when extreme conditions demand it.)
  • Who is responsible for the repair costs of the service line?
    This varies from utility to utility. Some utilities will repair any leaks between the water main and the buffalo box (b-box) or valve box in the front yard. Other utilities will repair any leaks between the water main and the water meter. You need to check with your specific water utility.
  • I am going to be moving into a house. How do I know who is my water utility?
    The best way to determine who is you water utility is to ask to see a copy of the water bills for the house. If a water bill is not available you can ask a neighbor who provides water service. You should call the utility to verify this information.
  • Why are there water restrictions?
    As a condition of receiving Lake Michigan water each utility has to enact indoor and outdoor water restrictions. The indoor water restrictions include plumbing codes that require the installation of water conserving fixtures. Outdoor water restrictions include such things as restricting water sprinkling during the hottest time of the day to minimize evaporation. You need to check with your water utility to find your specific water restrictions.
  • Do water filters work and should I use one?
    As with most products, some filters work better than others and some do not work at all. There are many types of filters available, each type works differently and will remove different substances from the water. It will be very helpful for you to know exactly why you want to filter the water before you speak to the seller of water treatment devises. If you choose to filter your water, there are several resources available to you to assist you in choosing a filter that works properly and will meet your needs. Consumer Reports Magazine occasionally will compare types of water filters and explain which types remove which constituents. They also compare various models and report on which ones work the best. A list of National Sanitation Foundation (NSF) approved water treatment devices is available by calling the NSF at (800) 673-8010.Please note: If you do install a water filter, follow the operating and maintenance instructions very carefully. An improperly installed and/or maintained filter can adversely affect the water quality. The water provided by the DuPage Water Commission meets all State and Federal drinking water standards.
  • Do I need to treat the water before I use it for my fish?
    Yes. Your drinking water contains disinfectants to inhibit bacterial growth. These disinfectants can kill fish. The water supplied by the DuPage Water Commission contains chlorine. Chlorine can be neutralized by adding the appropriate chemicals, which are available at most pet stores. Chlorine can also be removed with a granular activated carbon (GAC) water filter. Chlorine can also be removed from the water by letting a container of the water sit exposed to the atmosphere (uncovered) for at least 48 hours.Some fish, particularly tropical fish and koi, are also sensitive to rapid changes in the temperature and pH of the water – even small changes. If you are going to change the water in an aquarium or pond, or add a significant amount of new water, consult an experienced fish care expert for tips on how to accomplish this without shocking or killing your fish.Some people may be concerned that water harmful to fish might not be safe for them to drink. This concern is not necessary. Humans and fish use water in very different ways. When humans drink water, the chlorine is neutralized by our digestive system before it enters our bloodstream. When fish “breathe” water, any chlorine present enters their bloodstream directly. This interferes with the fish’s ability to take oxygen from the water and can cause the fish to suffocate.
  • Why does my water sometimes smell or taste like chlorine?
    Chlorine is added to drinking water for several reasons. First and foremost, the Illinois Environmental Protection Agency and the United State Environmental Protection Agency require that all water plants disinfect the water. The Chicago Water Department uses chlorine for this purpose. Second, a minimal amount of chlorine is added to assure that the water remains safe as it travels from the treatment plant to your home. A few individuals, who are sensitive to chlorine, can detect the chlorine taste and odor at these low levels.
  • Does the water contain fluoride?
    Yes. In Illinois, the Department of Public Health requires the addition for fluoride to potable water to provide children with the proper dental healthcare. Fluoride in drinking water is primarily absorbed into the blood stream and deposited on the teeth of children up to the age of about 8.
  • How hard is my water and should I use a water softener?
    Dissolved minerals make water hard; as the amount of minerals in the water increases, the water becomes harder. Two common minerals found dissolved in drinking water are calcium carbonate and magnesium carbonate. There is usually much more calcium carbonate than magnesium carbonate present in water; therefore, water hardness is reported as the amount of calcium carbonate (CaCO3) dissolved in the water. There are two units of measurement for hardness commonly used in the United States, grains per gallon and milligrams per liter calcium carbonate (mg/L as CaCO3). The conversion factor is 17.1 mg/L as CaCO3 = 1 grain per gallon. Our water is about 8 grains per gallon or 137 mg/L as CaCO3. Average well water hardness is 55 grains per gallon or 941 mg/L as CaCO3.Water softening is the process of removing the minerals from the water and is commonly accomplished by either reverse osmosis filtration or ion exchange. Reverse osmosis filtration units can handle only small volumes of water and is usually performed at a single point of use, such as the kitchen sink. Ion exchange units can handle large volumes of water and are usually installed on the incoming water supply line to a property. Ion exchange systems exchange sodium ions for the calcium and magnesium ions in the water. Medical studies show that people who live in areas with hard water have reduced occurrences of cardiovascular illness compared to people who live in areas with soft water. You should consult your physician before making artificially softened water your primary source of drinking water.
  • Do I have radon in the water?
    No. Radon is virtually nondetectable in surface water supplies such as Lake Michigan.
  • How can I have my water tested?
    Services for water testing are available from private laboratories for a fee. This fee varies greatly depending on the number of constituents you would like tested for in the water. The Chicago Water Department, Water Quality Bureau, Water Purification Laboratories, performs quarterly chemical analysis on the water they supply to the Commission. The Commission sends water samples to the Illinois Environmental Protection Agency Laboratories monthly for bacterial testing. The Commission’s water meets all State and Federal drinking water standards. To obtain a booklet of qualified laboratories call the Illinois Environmental Protection Agency, Division of Laboratories, at 217-782-6455.If you would like to see the Chicago Water Department, Bureau of Water Quality, Water Purification Laboratories Comprehensive Chemical Analysis visit the Comprehensive Chemical Analysis for the City of Chicago Water Supply at the Commission’s web site.
  • What is that black stuff at the bottom and sides of the toilet? 
    Bathrooms tend to have a higher humidity which is very supportive for mold growth. The mold is eating organic dirt/dust which is landing on the toilet. Some molds can even grow in the water on the inside walls of the toilet water supply tank and the toilet bowl itself. You should wash the toilet frequently with Borax laundry detergent, a natural mold cleaner. You may have discovered that bleach cleans the bowl and kills the mold there. One reason it keeps coming back is that one of the ‘black molds’, Cladosporium, is one of the most common molds in the world, in fact it is the most common mold found in air samples collected indoors and outdoors. We are being exposed to it all the time. Even right now!!! Exposure to high levels of Cladosporium can cause allergy or even asthma in highly sensitive individuals, but it is not generally considered ‘dangerous.’ Cladosporium is defiantly the most common bathroom mold, it really likes warm, damp places, and in fact it does just fine in places that are even wetter than moist or damp and is better adapted to smooth nonporous surfaces than many others. So no matter how sparkly clean you get that toilet, as soon as you are finished, here come some more spores just drifting along in the air. Even though it can grow on the smooth surface it might help to give the bowl a treatment with really strong mineral and rust remover to get rid of any irregularities that give it a place to lodge.Another reason it keeps coming back is that the mold, or at least some spores, are not just in the bowl, they are in the tank, between the tank and bowl, in the hinges of the seat, and in all the nooks and crannies of the various parts in the tank. You can try squirting some bleach solution up between the tank and bowl. But you need to treat the tank, take a look in there and you’ll probably see some mold. Get yourself a bottle of bleach, a cup, and some rubber gloves and a stick. Flush the toilet and before the tank is half full reach down and close the flapper, use the stick if your gloves aren’t long enough or you don’t want to stick your hand in there for some reason, it’s just water. As the tank fills carefully pour in the bleach, save a cup or so of bleach. Just let that sit in there for a while, it is a very strong solution; make sure the area is well ventilated. While the tank is soaking, take that saved bleach and pour it down the overflow tube, that vertical pipe that sticks up above the water surface. That tube leads to the jets or holes all along under the rim there is probably mold in all the channels and jets. Ever once in a while use the cup to pour some of the solution down the tube. After 10, 15 minutes or so flush the toilet and then push the flap back down at the halfway point again and let the tank refill again. Instead of completely flushing and letting that solution just gush on thru, we are trying to keep a stronger solution in contact with the internal connections as long as we can. After another 10 minutes or so go ahead and flush the toilet. You can let that sit in the bowl as long as you can stand it. The chlorine smell will go away after a few flushes. Before you put the lid back on the tank drop in one of those products like tidy bowl, just so long as it is the kind you put in the tank and not just the bowl. Choose a brand that claims to fight molds, it will usually say it has chlorine bleach in it. There are more efficient products available from a local janitorial supply, house and you may find a device which you can fill and refill with your own bleach.You also should investigate this possibility: that your home has elevated levels of airborne mold spores. You can use do it yourself mold test kits available at a large home improvement, hardware, or safety store to mold test the air of each room, basement, crawl space, attic, garage, and the outward air flow from each heating/cooling duct register, to determine the possible presence of elevated levels of airborne mold spores, in comparison to an outdoor mold control test.
  • What is this pink residue in my bathroom?
    Pink residue is generally not a problem with water quality. In fact, pink residue is likely a result of airborne bacteria which produce a pinkish or dark gray film on regularly moist surfaces. Such surfaces include toilet bowls, showerheads, sink drains, and tiles. Some people have also noted that the pink residue appears in their pet’s water bowl, which causes no apparent harm to the pet and is easily cleaned off. Due to the expense of having the bacteria tested, most homeowners never identify the exact type of bacteria that is causing their problem. However, many experts agree that the bacteria that causes these pink stains is most likely Serratia marcesens, a bacteria which is found naturally in soil, food, and in animals. Serratia, which produce a characteristic red pigment, thrive on moisture, dust, and phosphates and need almost nothing to survive. These bacteria were thought to be harmless until recently, when it was discovered that in some people, Serratia marcesens is a cause of urinary tract infections, wound infections, and pneumonia.
    When can this happen?
    The pinkish film often appears during or after construction or remodeling, when dust and dirt containing Serratia bacteria are stirred up. Once the bacteria is airborne, it will seek a moist location in which it can proliferate. Some people have reported that the pink residue only appears during certain times of the year, when their windows are left open for most of the day. This bacteria is present in a number of environments and wind can carry the airborne bacteria or stir up dust in which the bacteria is present. The appearance of the pink residue can be intensified by the use of activated carbon filters, which remove chlorine from the water. The absence of the normal levels of chlorine in tap water allows Serratia to thrive.
    How do I get rid of the pink residue?
    The best solution to this problem is to continually clean the involved surfaces to keep them free from bacteria. Chlorinous compounds work best, but keep in mind that abrasive cleaners may scratch fixtures, making them more susceptible to bacterial growth. Chlorine bleach can be used periodically to disinfect the toilet and help to eliminate the occurrence of the pink residue. An easy way to do this is to stir three to five tablespoons of fresh bleach to the toilet tank, flush the toilet to allow the bowl to be disinfected, and add another dose of bleach to the tank as it is refilling. Use of a toilet cake that contains a disinfectant can keep residual disinfectant present in the toilet at all times. By keeping bathtubs and sinks wiped down and dry, the formation of pink residue can be avoided. Cleaning these surfaces with a solution that contains chlorine will also help to minimize the occurrence of pink residue.