It is very difficult to separate taste from odor because these two human senses are so closely related. Most occurrences of a peculiar taste or odor that you may experience can be grouped into one of the following two categories:

1) chlorinous, bleachy  2.) fishy or earthy

Two common causes for a chlorinous bleachy taste or odor in the water: the addition of chlorine to the water by the District, and the interaction of that chlorine with a build-up of organic material in your plumbing system. A chlorine odor is often an indicator that the disinfectant is effectively working to remove bacteria and debris in your pipes. The District uses a relatively low dose of chlorine in its system; however, sensitivity to taste and odor varies greatly from person to person so while one person may notice a strong smell of chlorine another may not.

Two common causes of fishy, earthy taste or odor in the water: certain types of organisms growing in the District’s source water reservoirs, algae, fungi and bacteria excrete small amounts of chemicals into the water which can impart a taste and odor. The two most common chemicals are geosmin and methylisborneal (MIB). Although these chemicals have no documented health effects, most people can detect them in the water at concentrations as low as 5 parts per trillion. The District works very hard to avoid having these compounds reach our customers and treats the water specifically to avoid this.

Refrigerating the water can help eliminate the odor and adding a slice of lemon will remove any bitter taste.

Odors that seem to emanate from your tap may be from the sink drain and not the water. The plumbing beneath your sink, typically the u-shape pipe, can collect debris over time and create an odor at your tap. If you smell an odor, fill a clean glass halfway with tap water and smell the water in a separate room or outdoors. If the odor is no longer present, the odor is likely from the plumbing beneath your sink. We recommend pouring vinegar or baking soda down your drain to help clear debris and odor.


When the water from your faucet is brown it may be the result of a disturbance in the water main. Even though your water is filtered, over time a very fine layer of iron and sediment can develop on the bottom of the water mains that can be stirred up.  While the water is still safe to drink, it isn’t very pleasant to look at. Hydraulic disturbances caused by hydrant use, valve turning, main breaks or adjacent construction can stir up these sediments and cause the water to be brown. Usually the water will clear on its own within a few hours. If your water is brown:

Don’t drink the water. It may not be harmful, but we don’t advise drinking any obviously discolored or dirty water. It is fine to use this water to flush toilets.
Avoid using hot water until the pipes clear. That avoids drawing dirty water into your hot water tank.
After an hour or so, run the cold water for several minutes to see if it is clear. When one faucet runs clear, run the cold water through all home faucets until each is clear. This step will eliminate the dirty water that may have been drawn into your pipes.
If this does not go away in a few hours, you should call the District at (860) 278-7850 X 3600 .

To prevent dirty water from being delivered to our customers the District regularly flushes fire hydrants throughout the distribution system to clean the mains in the streets and remove scale build-up in pipes. When crews flush hydrants and remove this material from the hydrant and several miles of pipe, it comes out of a hydrant all at once, and the water may initially look discolored. If you watch our workers flush, you will notice that the water clears up rather quickly.


That appearance of a milky color is really air bubbles. When the outside temperature drops, our pipes get cold and so does your drinking water. Bring that cold water into a warm home, and oxygen gas is released into the water as tiny bubbles. Fill a glass with water and let it stand for a few seconds. If the water clears from the bottom toward the top, the milky color is just the oxygen bubbles rising, similar to opening a bottle of soda.


The Districts drinking water is soft. If you are a District customer, you probably don’t need to use special water softeners for your clothes- or dishwashing machines.

Water’s “hardness” and “softness” is due to its concentration of minerals – calcium and magnesium. The lower the mineral concentration, the softer the water is. The District’s drinking water has a hardness of approximately 15 milligrams per liter, or 1 grain per gallon.

Using water that is considered soft, you do not need to use as much dishwashing soap, laundry detergent, or other soaps. Many new dishwashers allow you to set the hardness of the water so that you do not need to use as much soap in comparison to areas that have hard water.


The State of Connecticut Health Department requires the addition of fluoride to all public drinking water provided by systems serving a population of 20,000 or more people. A daily diet that includes small amounts of fluoride has been credited with reducing the number of cavities in children and young adults. The normal fluoride level in the District’s water is 0.7 part per million.


Tap water may interact with the different metals used in home plumbing systems or airborne bacteria and produce colorful results. While the stains may be bothersome, your water will usually still be safe to drink and use. Stains and their causes include:

If you are experiencing a dark gray / black stain or slippery residue in the shower, tub, showerhead, toilet, a faucet, or in the washing machine, you do not have a water quality problem and you need not fear a health issue. These residues indicate the presence of naturally occurring mold (fungi), possibly in combination with bacteria present on the surfaces.

Mold spores that result in black residues are present outdoors in leaves, soil and mulch especially when moist. They enter homes through open windows and doors, on your pets, and in your own hair and clothing. You will not be able to keep them entirely out of your home. Mold spores that find a moist environment, especially where it is dark and air flow is limited, will survive and thrive.

The mold will not survive in chlorinated drinking water, however, a constantly damp surface where water stands long enough to lose its’ residual chlorine disinfectant will serve as a prime growth site. Shower curtains, toilets or inside the aerator on your faucets are just a few examples. This condition will be further intensified if chlorine is removed from the drinking water by way of a household filter.

Cleaning problem areas with a product that contains bleach or a disinfectant will keep mold growth under control. For faucet aerators, remove and soak them in a dilute bleach solution and use an old toothbrush to scrub them. Wipe out the inside of the faucet with the bleach solution also.

A pinkish slimy film may appear in your toilet bowl, shower stall, pets dish or other places where there is a relatively moist surface. This film most likely results from the airborne introduction of the bacteria “Serratia Marcescens” into a moist environment. This bacteria moves with dust in the air and is not in the water being delivered to your home, however, given the right environment it will proliferate rapidly.
For More information, download the American Water Works Association article: “What’s This Pink Stuff in My Bathroom?”

Reddish-brown stains on sinks or plumbing fixtures are most often noticed along with brownish water. They are found in homes of any age, although they are most common in older homes with galvanized pipe. Reddish brown stains may indicate rust forming in the pipes.

Green stains on plumbing fixtures are a result of copper leaching from the plumbing in your house and is usually associated with a continuously leaking faucet . This is not usually a problem for District customers, although the problem may occur from time to time. The District does adjust the pH of the water and adds an additional chemical to reduce the tendency of copper and lead to leach into your drinking water.

Regular cleaning with common household cleaners can help control the above mentioned stains and bacterial growth on sinks or plumbing fixtures.


The District treats its drinking water so that it has a pH of approximately 7.5, a slightly alkaline measurement. This pH level helps reduce the tendency for water to leach metal out of your household plumbing.

Untreated, “raw” water in the District’s Reservoirs has a pH of approximately 6.8, close to neutral.

pH measures the amount of hydrogen ion activity in a substance. The pH scale is relative and runs from 0 to 14. 0 is the lowest, and most acidic, pH level. 7 is neutral. 14 is the highest, and most alkaline, pH level.


The District tests for sodium regularly and the amount of sodium in the drinking water averages 8.4 milligrams per liter (about 2 milligrams per glass). This is considered to be a very low level of sodium by the FDA. Sodium in water contributes only a small fraction of a person’s overall sodium intake.


Usually colored particles in drinking water indicate the dip tube in your hot water heater is disintegrating. The dip tube is a long tube inside the water heater. It connects to the cold water pipe at the top of the heater and takes the cold water down to the base of the water heater to the heating element.

 The majority of water heaters made in the 1990’s utilized a dip tube made of plastic (PVC) which breaks down. It starts to break down from the bottom and over time the flecks get into your pipes. While the majority of particles are white, household plumbing can alter their color, copper plumbing can turn them blue/green while galvanized iron can turn them a reddish color.  They clog the faucets with screens and hot water hoses which are connected to appliances. They will clog up shower heads. As the dip tube gets shorter and shorter you have less and less hot water. The water heater has to work much harder to heat up water since the cold water takes up more space. 

When this happens, the dip tube needs to be replaced. Contact the manufacturer to get the best information on replacement. Many people will want to call a plumber who can flush the hot water heater at the same time. The flecks are not toxic or harmful.

If you have filters attached to your plumbing system or a water pitcher that uses carbon filters to remove contaminants, these can also contribute to the presence of black particles. The small carbon particles of these filters are black and can pass through in your water. Black particles can also come from precipitated iron and manganese in water, which may come loose from pipe walls after a large main break or major construction.

Another common cause of black particles in tap water is the disintegration of rubber materials used in plumbing fixtures. Plumbing gaskets and o-rings disintegrate over time and can collect in toilet tanks and around faucets.

Flushing the system and your taps will likely resolve the issue of black particles caused by plumbing fixtures or construction. If black particles are from your filter, you should replace the filter as recommended by the manufacturer.

White residue is commonly found in showers and kitchenware as the result of dissolved minerals found in water, such as calcium and magnesium. Mineral particles can also be visible in ice cubes made with tap water. These minerals are not a risk to human health but can build up on surfaces over time. Commercial products are available to remove white residue caused by minerals in water.

If you wish to do a further test you could take some of these particles and put them in a glass with some vinegar. The plastic will not melt, minerals will dissolve.