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Common Drinking Water Quality Concerns

Two women sitting at a table across form each other, one with a glass of clear water
Environment, Great Lakes, and Energy

Common Drinking Water Quality Concerns

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has developed this page to aid you in identifying the most common drinking water quality issues and solutions when you’re connected to a public water supply.

Basic considerations

To help you troubleshoot a water quality issue, ask the following questions:

  • Does the problem occur all the time, periodically, or seasonally?
  • Does the problem occur at some or all inside taps?
  • Does the issue occur only when you first turn on the water or does is occur continuously?
  • Does the issue occur with just cold water, hot water, or both?
  • Have you had any recent work done on your water plumbing and faucets?
  • A fish with green wavy lines coming off it, symbolizing an unpleasant earthy / musty / fishy / moldy odor

    Earthy / Musty / Fishy / Moldy

    These odors can be caused by algae blooms in source water and are typically a short-lived, seasonal event.

    Contact your water supply officials.

    An open manhole cover with green wavy lines coming off it, symbolizing a sewage odor

    Sewage Odor

    If you experience this odor seasonally, it may be due to agricultural runoff. If this odor is present all the time, the odor may be coming from the sink’s drain instead of the water. This is due to the running water stirring up the odor into the air. The odor could also be coming from the hot water. Hot water can have a foul odor when bacteria grow on the magnesium rod in the water heater tank. If you are worried about harmful bacteria being present in your water you could contact your water supplier, your local health department, and/or the Department of Environment, Great Lakes, and Energy.

    A cracked egg with green wavy lines coming off it, symbolizing a sulfur or rotten egg odor

    Sulfur Rotten Egg Odor

    If you experience this odor mainly with hot water, there may be bacteria in the tank of your water heater causing hydrogen sulfide gas. The odor may be associated with the magnesium rod in the hot water tank. If this is the case, replacement rods and rods with different material than magnesium can be installed to help correct the issues causing the smell. Contact a licensed plumber for further assistance.

    If you have a private well and are experiencing a sulfur/rotten egg odor with both hot and cold water, there may be iron bacteria creating hydrogen sulfide gas. Disinfection of your well may be needed. To get your well checked or disinfected, contact a well driller to help you.

    A bottle of bleach with green wavy lines coming off it, symbolizing a chlorine or bleach odor

    Chlorine / Bleach Odor

    If you experience this odor all the time, or periodically, it may be caused by the use of disinfectant in the drinking water. Chlorine is a common disinfectant used in public water supply systems to reduce or eliminate bacterial growth. Typically, when drinking water has a chlorine odor that makes it smell like bleach, or a swimming pool, this is due to the drinking water not having enough chlorine in it. When the right amount of chlorine is added, the average person cannot smell or taste chlorine in the water.

    Contact your water supply officials for more information.

    Still water with green wavy lines coming off it, symbolizing a stagnant or stale taste and odor

    Stagnant / Stale Taste and Odor

    If you experience this issue all the time, or periodically, you may be in a low flow, dead end area of a water supply system and fresh water may not be replenished at an ideal rate.

    Contact your water supply officials about a flushing routine.

    Plumbing with green wavy lines coming off it, symbolizing a plastic odor and/or taste

    Plastic Odor and Taste

    If you experience a plastic odor and taste in your water, this could be due to PEX or other plastic plumbing materials present in your plumbing.

    A test for volatile organic compounds can help confirm if these plumbing items are the cause.

  • A cloudy glass of water

    Cloudy / Milky / White or Gray Water

    If you experience cloudy or milky, white or gray water that clears after the water sits for a few minutes, then the cloudiness is likely tiny air bubbles escaping from the water. These air bubbles can get into the water in many ways, but the most common is due to the aerator, or screen, on the faucet which is designed to conserve water and reduce splashing of water out of the sink.

    If the cloudiness does not settle, and leaves a film on dishes, faucets, etc., then the cloudiness may be from naturally occurring minerals such as calcium or magnesium in the water. When these minerals are present in larger amount in the water, then the water is typically considered to be “hard water.” Other issues you may notice with hard water include a film or rainbow-like color on top of coffee or tea, or white deposits that form at the ends of faucets and shower heads.

    A glass of water with sand/sediment in it

    Sediment / Sand in Water

    If you experience this issue only when using hot water, then your water heater may be contributing to this problem. Has the water heater been flushed in the last 1-5 years? Follow your water heater’s manufacturer’s guidance for routine maintenance instructions including routine flushing for sediment removal.

    If you experience this issue when using cold water only, contact your water supply officials to see if any routine flushing of the system or water main breaks have occurred. When these activities occur, particles can be dislodged from the inside of the pipes and find their way to customers’ faucets. Flushing and cleaning out the plumbing will remove the debris from the plumbing.

    • Read EGLE's guidance on residential home flushing. Please note that this guidance is written for when water service is restored to a home although it is still good guidance when trying to clean out debris from your plumbing system.
    A glass of reddish/rusty colored water

    Red, Brown, or Yellow Water

    If you experience this issue all the time, it could be caused by naturally occurring iron in groundwater. Older galvanized plumbing in your home and cast iron mains in the system may also contribute to the issue. Contact your water supply officials to see if they have any more information. There are several options available to treat your water for iron removal. Contact your local plumber or treatment company for further assistance.

    If you experience this discoloration for just a short period of time, it could be because your water system performed a routine cleaning of the water mains or because of a recent water main break. Contact your water supplier for more information.

    A glass of blue/greenish colored water

    Blue or Green Water

    Blue or green water can be caused by copper plumbing. If your copper pipes are experiencing severe corrosion the result is oxidized copper, which is a blue or green color. Have you had new copper plumbing recently installed? New plumbing can take a little time to become acclimated to the drinking water. During this “break in” period, higher levels of copper can find their way into the drinking water. Flushing water for a period of time before using it is the best way to make sure you are not getting too much copper in the water you are drinking. Please consult a licensed plumber if the problem persists.

    A glass of pinkish colored water

    Pink or Red Water

    Various molds and Serratia bacteria found naturally in surrounding air and on our bodies may be causing this color. If there is concern that the drinking water has harmful bacteria, a Total Coliform or E. Coli test can be taken.

    You can contact your local water supply officials, the local health department, or EGLE for more help.

    A glass of water with black flecks in it

    Black Water or Black Flecks

    If the water is black in color or there are black flecks present in the hot water only, it may be a result of the water heater’s magnesium rod. Contact a licensed plumber to help you evaluate your water heater.

    If the water is colored black or has black flecks only in the cold water, then it may be caused by the presence of manganese in the drinking water. Manganese is a naturally occurring mineral that when oxidized turns black. Contact your local water supply officials to let them know what you are seeing.

  • A shower head with weak, unpressurized water dripping from it symbolizing low pressure or low flow

    Low Pressure / Low Flow

    If you suddenly are experiencing low pressure or low flow throughout your entire residence, contact your water supply officials to see if there is a nearby issue affecting your supply. If your water pressure or water flow is only slow in one part of your home, it is likely due to a clog in either the pipes or fixtures. Contact a licensed plumber to help find and fix the issue.

    If the low pressure is only at one tap, remove and clean the aerator.

For more information

For more information on drinking water, visit

If you still have a concern about your drinking water, find more information or report a concern via the Office of the Clean Water Public Advocate’s Drinking Water Concern System.