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Water Quality Frequently Asked Questions

Ice cubes made from tap water are seldom perfectly clear, for a perfectly good reason: The water contains dissolved calcium and other naturally occurring minerals. When the water is frozen, the minerals turn into harmless solid white particles that make the water appear cloudy.

Reddish or rusty water is a common result of older pipes in your home. When water stands in the pipes for long periods of time (including overnight), fine particles of rust may accumulate. Another possible cause may be a rusting hot water heater. The problem can easily be solved by letting the water run for a few minutes to clear out the pipes. Rusty water is not a health hazard, but you may want to avoid doing laundry with the rusty water to avoid staining.

Some parts of the distribution system have older cast iron mains. When water moves through those pipes faster than usual, such as when a hydrant has been opened for flushing or firefighting, discoloration of water can occur. If it makes its way into your home plumbing, this discoloration can typically be flushed away by letting the cold water run for a few minutes. If the discoloration persists after you have thoroughly flushed your home water pipes, please let us know.

Chlorine is a naturally existing element that is used to disinfect drinking water supplies to prevent waterborne diseases such as cholera, typhoid fever, and dysentery. The Maine CDC Drinking Water Program requires that chlorine be added to all reservoir water supplies. Groundwater supplies may also be chlorinated. Chlorine has residual properties that allow it to continue disinfecting as water travels from the treatment facility to your home. Chlorine has been added to disinfect drinking water in America since about 1900.

We add as little chlorine as possible to our water while still maintaining an adequate level for disinfection. We work to maintain a chlorine level in our distribution system of one part per million. However, we understand that some customers object to the taste and smell of chlorine even in small amounts. Fortunately, the taste and smell of chlorine can easily be removed by refrigerating tap water in a sealed container, preferably glass. Some plastic bottles can add their own taste to the water. Having a bottle of ice water in the fridge also helps conserve water because you don’t have to let the tap run for the water to get cold.

Chlorine reacts with organic material naturally present in water supplies and creates new compounds known as disinfection by-products “DBPs”. The U.S. Environmental Protection Agency (EPA) currently regulates a group of DBPs known as Trihalomethanes. Animal research using high concentration of DBPs suggests a link to a high risk of certain types of cancer. The EPA has not been able to link exposure to DBPs at low concentration levels with the health risks associated with concentration level exposure.

The water we provide to you has very low concentrations of DBPs and does not represent a significant risk of exposure to these compounds. Research on the relationship between DBPs and cancer and other health risks is ongoing. However, the disease prevention benefits far outweigh the risks associated with cholorinated drinking water.

Our surface and ground water sources from lakes, rivers and wells, are excellent sources of drinking water. With over 6000 lake and ponds, Maine has some of the best water sources in the country.  We use various treatment methods and monitor treatment to ensure we deliver safe drinking water to your tap every day. 

The disinfection of public water supplies is one of the most important functions of a public water system operation.  Meeting disinfection requirements of the Safe Drinking Water Act regulations has all but eliminated typhoid, cholera, and dysentery in our country. Today’s regulations require that we treat and test, not only for elements that cause water-borne diseases, but also for a host of other potential hazards.

Disinfection of drinking water is one of the major public health advances in the twentieth century. In the early 1900s, typhoid and cholera were common throughout American cities; disinfection was a large factor in reducing these epidemics. Chlorine was the preferred disinfectant back then and continues to be the most widely used substance for water disinfection in the United States.

Safe drinking water has played a key role increasing human life expectancy from about 45 years in the early 1900s to about 76 years at present.  Since disinfection of public water supplies began, there has been dramatic decline in infant mortality rates and the virtual elimination of cholera, typhoid fever, dysentery and gastroenteritis, as well as many other waterborne diseases which once killed tens of thousands of Americans.

For more information on the history of drinking water disinfection visit:

"Rotten egg" smells may be caused by a problem in your hot water heater. Magnesium anodes used in hot water tanks to prevent corrosion sometimes generate bad smelling gasses. The odor usually occurs early in the morning and only with your hot water. This smelly problem may be easily fixed by replacing the magnesium anode with one made from an aluminum alloy. Before replacing the anode, be sure the odor is coming from the hot water and not from the sink drain or garbage disposal. If you have any questions about repairs, contact a plumbing professional.

During any time of year but especially summer, when the air is much more humid, we typically receive calls with questions about pink, brown, black and red staining in toilet bowls, sinks and shower stalls. 

There is a common misconception that these stains, slimes, rings or residues are caused by the water from your distribution system. Your water is disinfected with chlorine and does not promote the growth of mold. The source of the concern is not the water but rather airborne spores of naturally occurring, common, household molds and mildews that thrive in moist, humid or damp environments. These organisms need water to grow and will settle on wet areas and grow sometimes very rapidly. The airborne spores will even feed on human products that contain phosphates and fats such as soaps, gels, shampoo, cosmetics, toothpastes, personal care products and human waste products. 

Controlling ventilation, moisture, dampness and humidity, coupled with frequent and routine cleaning (including drains), will help control the growth and spread of these airborne molds and mildews.

Being diligent with cleaning will help keep the organisms from growing and causing discoloration.

Fluoride is a naturally occurring mineral that is added to public water systems in accordance with public health requirements. Maine Water fluoridates some of our water systems as required by state law.  

The Maine Water Company operated systems that are fluoridated include:  Biddeford - Saco, Bucksport, Camden Rockland, Freeport, Hartland, Millinocket, Skowhegan, Oakland (fluoridated by Kennebec Water District), Fryeburg, and South Freeport.  Union and Waldoboro have natural fluoride in the water at levels below the maximum allowed level.

For more facts about fluoride, visit our Fluoride Fact Sheet.

Maine Water has an extensive program of water quality protection that includes land ownership, watershed inspections, and source water quality monitoring. In addition, regular water quality testing is done in all of our water systems and continues to show that the water delivered to our customers is high-quality and in compliance with state and federal drinking water standards. Our water quality testing data is regularly reviewed for potential changes or trends and any customer water quality complaint is escalated to professionals in our water quality team.

When water looks milky or cloudy when pouring from the faucet, it is likely due to air being released from the water.  This mostly happens in the winter and is usually noticed more in the hot water.

Water from lake and river sources holds more oxygen in winter months because the water is cold and air is more soluble in cold water.  Similar to soda, when the water is warmed up it will release the air more readily.  As water travels from the treatment plant where it is fresh, cold and under pressure from the pumps sending it to the system of pipes throughout the community, it holds most of the air trapped in the water. 

Upon entering your home it warms up (especially if it goes to the hot water system).   When drawing the water from the faucet, the pressure is reduced and air is released, similar to opening a bottle of soda.  This will look like milky water and if you let it set for a few minutes, the air rises to the top and oxygen is released into the atmosphere.

There is no reason for concern and you can use your water as you normally would.

Air can get trapped in your home plumbing and will find its way to the highest points in the plumbing as air rises.  Starting with the cold water, from the lowest level of your building and working up to the top floors, flush the sink faucets, showers, and utility sinks.  It is helpful to remove the aerators on the ends of the sink faucets when flushing, if present.  It is also helpful to run the water as hard as possible without causing the sink to overflow.   Trapped air can take a few days to work its way out but regular use should help.

Tap water must be treated first to remove disinfectants for use in aquariums. Consult your local pet store for further information.

We flush our entire system at least every other year by opening and flushing hydrants in a sequential manner. This allows us to remove any particles settled in the water line.  These are typically iron deposits that form as metal pipes corrode over time.  Flushing helps maintain good disinfectant residuals and is an important method to maintain excellent water quality.

By flushing in a specific sequence, we ensure that “clean” water moves across the system. We typically start at the treatment plant and work our way out to the ends of the system.  By flushing at a specific flow rate, we ensure that flushing is effective while disrupting water pressure as little as possible to nearby customers.

For more information, click to view our video on hydrant flushing:

Maine Water disinfects the public drinking water with chlorine to prevent contamination by disease causing organisms.  You may notice a chlorine smell or taste some or all of the time.  We pay very close attention to the levels of chlorine with routine testing and continuous monitors.

Internal plumbing systems sometimes are stagnant such as overnight when people are sleeping or when buildings are unoccupied for a period of time, such as when residents are at school or work or on vacation.  Stagnant water can give an off taste or smell to the water so flushing the water lines, making sure to run all faucets in the building, greatly reduces stagnation and flushes out metal contaminants from the plumbing that have leached into the water as water sets in the pipes. 

If a building has been idle for a period of days or weeks, it will be very important to run cold water, starting at the nearest faucet to the meter (at the water pipe entrance into the building), working all the way to the farthest faucet from the meter.  If the building is two or more stories tall, flush starting at the lowest floor working up to the highest. In this case flushing each faucet well is important.  Remember to clean the aerators at the ends of the faucets as well.

Sometimes sink drains release gases if they have accumulated materials like food, soaps, toothpaste, hair etc.  An off odor will be released when the water is turned on, forcing gases up through the drain.  Cleaning the drains should take care of this. 

If you notice a mold-like smell, you could have environmental mold growing around the wet areas of your shower, tub, toilet, and sinks.  Mold does not come from the water but needs water to grow and thrive.  Mold spores are in the air and are common causes of discoloration around water fixtures.  Regular cleaning and elimination of mold sources will reduce growth.