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MWRA's Drinking Water Test Results for 2014 Published June, 2015
Massachusetts Water Resources Authority
cover of 2014 annual waqter quality report

HTML Version- Metro Communities

Below are MWRA's 2014 Drinking Water Test Results for MetroWest and Metro Boston communities that receive all of their drinking water from MWRA.

Results for partially-supplied communities and Chicopee, South Hadley and Wilbraham are available for download (PDF).

This report includes the results of those tests for 2014. This report is required under the federal Safe Drinking Water Act Public Law 104-12, Section 1414 (C), PWS ID #6000000.

Back to MWRA 2014 Annual Drinking Water Test Results Main Page

Download a PDF of this report (Metro version)

en Español for 2014 (PDF)

Annual Water Quality Report Archive

All MWRA Water Quality Tests


Message from MWRA Executive Director Fred Laskey


Dear Customer,

Clean, fresh water that tastes great – that’s what you expect when you fill your glass, and that’s what MWRA delivers right to your faucet. In fact, MWRA water was chosen as the best tasting in the country in 2014 at an annual conference of water specialists.

And it’s not just the taste of the water that’s good. MWRA takes hundreds of thousands of tests each year, and your water met every state and federal drinking water standard. System-wide, we remain below the Lead Action Level. Please read your community’s letter for more information on your local water system.

There are several reasons our water tastes so good, beginning with high-quality source water. Next is the state-of-the-art treatment we provide - starting with ozone in 2005 and then adding UV light in 2014.

After treatment, the water does not see the light of day until it reaches your tap. MWRA is now finishing up construction of the last of its covered water storage projects with the Spot Pond Tank in Stoneham slated for completion later this year.

We hope you take a few moments to read this report. We want you to have the same confidence we have in the water we deliver to over 2 million customers. Please contact us if you have any questions or comments about your water quality or any of MWRA’s programs.


Frederick A. Laskey
MWRA Executive Director



Where Does Your Water Come From?

Award Winning Tap Water!

In 2014, MWRA won Best Tasting Water in the US at the American Water Works Association Annual Conference. We competed against water suppliers from across the country. MWRA also received the Public Water System Award for excellent performance from the Massachusetts Department of Environmental Protection.

Why Your Water Tastes Great -- High Quality Source Water

Your water comes from the Quabbin Reservoir, about 65 miles west of Boston, and the Wachusett Reservoir, about 35 miles west of Boston. These pristine reservoirs supply wholesale water to local water departments in 51 communities. The two reservoirs combined supplied about 200 million gallons a day of high quality water to consumers in 2014.

The Quabbin and Wachusett watersheds are naturally protected with over 85% of the watersheds covered in forest and wetlands. To ensure safety, the streams and reservoirs are tested often and patrolled daily by the Department of Conservation and Recreation (DCR).

Rain and snow falling on the watersheds - protected land around the reservoirs - turn into streams that flow to the reservoirs. This water comes in contact with soil, rock, plants, and other material as it follows its natural path to the reservoirs. While this process helps to clean the water, it can also dissolve and carry very small amounts of material into the reservoir.

Minerals from soil and rock do not typically cause problems in the water. But, water can also transport contaminants from human and animal activity. These can include bacteria and viruses - some of which can cause illness. The test data in this report show that these contaminants are not a problem in your reservoirs' watersheds.

The Department of Environmental Protection (DEP) has prepared a Source Water Assessment Program report for the Quabbin and Wachusett Reservoirs. The DEP report commends DCR and MWRA on the existing source protection plans, and states that our “watershed protection programs are very successful and greatly reduce the actual risk of contamination.” MWRA follows the report recommendations to maintain the pristine watershed areas.

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Map of the MWRA Water System


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Testing Your Water Every Step of the Way:
2014 Test Results

Test results show few contaminants are found in the reservoir water. The few that are found are in very small amounts, well below EPA's standards. Turbidity (or cloudiness of the water) is one measure of overall water quality. All water must be below 5 NTU (Nephelometric Turbidity Units), and water can only be above 1 NTU if it does not interfere with effective disinfection. In 2014, turbidity was always below both the 5.0 and 1.0 NTU standards, with the highest level at 0.62 NTU. Typical levels at the Wachusett Reservoir are 0.3 NTU.

MWRA also tests reservoir water for pathogens such as fecal coliform, bacteria, viruses, and the parasites Cryptosporidum and Giardia. They can enter the water from animal or human waste. All test results were well within state and federal testing and treatment standards.

Test Results - After Treatment

EPA and state regulations require many water quality tests after treatment to check the water you are drinking. MWRA conducts hundreds of thousands of tests per year on over 120 contaminants (a complete list is available on Details about 2014 test results are in the table below. The bottom line is the water quality is excellent.

Test Results After Treatment
Details about 2014 are listed. The bottom line is that the water quality is excellent.
(We found) Detected
Range of
How it gets in the water
Common mineral in nature
Water disinfectant
Additive for dental health
Nitrate ^
Atmospheric deposition
Nitrite ^
Byproduct of water disinfection


Byproduct of water disinfection
Byproduct of water disinfection
Total Coliform
0.5% (Nov)


Naturallly present in the environment
Combined Radium


Erosion of natural mineral deposits

KEY: MCL=Maximum Contaminant Level. The highest level of a contaminant allowed in water. MCLs are set as close to the MCLGs as feasible using the best available technology.
MCLG=Maximum Contaminant Level Goal. The level of contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety. MRDL=Maximum Residual Disinfectant Level. The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants. MRDLG=Maximum Residual Disinfectant Level Goal. The level of a drinking water disinfectant below which there is no known or expected health risk. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contamination. ppm=parts per million ppb=parts per billion ns=no standard ^As required by DEP, the maximum result is reported for nitrate and nitrite, not the average.


Tests in Community Pipes

MWRA and local water departments test 300 to 500 water samples each week for total coliform bacteria. Total coliform bacteria can come from the intestines of warm-blooded animals, or can be found in soil, plants, or other places. Most of the time, they are not harmful. However, their presence could signal that harmful bacteria from fecal waste may be there as well. The EPA requires that no more than 5% of the samples in a month may be positive. If a water sample does test positive, we run more specific tests for E.coli, which is a bacteria found in human and animal fecal waste and may cause illness. No E.coli was found in any MWRA community in 2014. If your community found any total coliform, it will be listed within your community's letter.


Ongoing Research for New Regulations

MWRA has been working with EPA and other researchers to define new national drinking water standards by testing for unregulated contaminants. To read more about these regulations, and to see a listing of what was found in MWRA water, please visit

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Why Your Water Tastes Great -- Water Treatment

One of the reasons that the Boston area water tastes so good is that MWRA has state-of-the-art treatment at the John J. Carroll Water Treatment Plant in Marlborough.

Since 2005, your water has been treated with ozone - produced by applying an electrical current to pure oxygen. Ozone has ensured strong protection against microbes and viruses, improved water clarity, and makes the water taste better.

Starting in 2014, we also added ultraviolet (UV) disinfection, further improving the quality of the water. UV light is essentially a more potent form of the natural disinfection from sunlight, and ensures that any pathogens potentially in our reservoirs are rendered harmless.

In addition, the water chemistry is adjusted to reduce corrosion of lead and copper from
home plumbing. Fluoride is added to promote dental health, and in April 2015 the dose was
lowered to 0.7 ppm based on CDC and EPA recommendations. Last, we add monchloramine, a mild and long lasting disinfectant to protect the water as it travels to your home.

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Investments in Your Water System

Preparing Dams for Climate Change
Since 2006, MWRA has spent over $21 million on dam safety projects. All MWRA dams, dikes, spillways and appurtenances are inspected routinely by licensed dam safety engineers and are in good condition.

Protecting Reservoirs While Providing Open Space
The best way to deliver clean, safe water is to start with high quality source water. Since 1985, $134.5 million has been invested in land preservation around the Quabbin, Ware and Wachusett watersheds.

Monitoring Water Quality in Real Time
Your water is monitored by a state-of-the-art system in real time – 24 hours a day, seven days a week – to make sure it is free of contaminants. This allows MWRA to respond to changes in water quality almost immediately.

Taking Advantage of Gravity
MWRA operates three hydroelectric generators that capture the energy of the water as it flows east providing $1.5 million in renewable energy annually.

Covered Storage Keeps Water Safe and Clean
MWRA has constructed a network of covered storage tanks across the service area that keep your water protected from the treatment plant to your tap. The Spot Pond Tank in Stoneham will open later this year.

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Facts About Lead

What You Need to Know about Lead in Tap Water

MWRA water is lead-free when it leaves the reservoirs, and MWRA and local pipes do not add lead to the water. However, lead can get into water through household plumbing including some service lines (the pipe from the street to your house). Check with your local water department if you have a lead service line. If you do, you should replace it.

Under EPA rules, each year your local water department must test water in homes that are likely to have high lead levels. The requirement is that 90% of the sampled homes must have lead levels below the Lead Action Level of 15 ppb. Since corrosion control treatment began in 1996, lead levels in tested homes have dropped over 90%, and 19 straight sampling rounds have been below the EPA Action Level. For tips on how to reduce your possible exposure to lead, visit


September 2014 Lead and Copper Results
Lead (ppb)
90% Value
(Target) Action Level

(Ideal Goal) MCLG

# Homes above AL/# Homes Tested
Copper (ppm)
ppb = parts per billion. ppm = parts per million. AL=Action Level-The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow. MCLG=Maximum Contaminant Level Goal The level of contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.


Important Information from EPA about Lead

If present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. MWRA is responsible for providing high quality drinking water, but cannot control the variety of materials used in plumbing components. If your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking.

If you are concerned about lead in your water, you may wish to have your water tested. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline at 1-800-426-4791 or, or MWRA at 617-242-5353 or

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Important Information from EPA and DEP

Drinking Water and People with Weakened Immune Systems

Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. EPA/CDC guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the EPA's Safe Drinking Water Hotline (1-800-426-4791).

Tap Water -
The Smart Choice

Although tap water and bottled water have to meet the same standards, tap water is delivered straight to your home without
trucking or plastic waste. Bottled water produces over 10,000 times the amount of greenhouse gasses compared to tap water.

Tap water costs less than a penny per gallon, while bottled water can cost between $1 and $8 per gallon. Tap water is the smart choice!

Contaminants in Bottled Water

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the EPA’s Safe Drinking Water Hotline (1-800-426-4791) or MWRA. In order to ensure that tap water is safe to drink, the Massachusetts DEP and EPA prescribe regulations which limit the amount of certain contaminants in water provided by public water systems. The Food and Drug Administration (FDA) and the Massachusetts Department of Public Health regulations establish limits for contaminants in bottled water which must provide the same protection for public health.

Facts About Sodium

Sodium in water contributes only a small fraction of a person’s overall sodium intake (less than 10%). MWRA tests for sodium monthly and the highest level found was 34.8 mg/L (about 9 mg per 8 0z. glass). This would be considered Very Low Sodium by the Food and Drug Administration.

Information about Cross Connections

The Massachusetts DEP recommends the installation of backflow prevention devices for inside and outside hose connections to help protect the water in your home, as well as the drinking water system in your town. For more information on cross connections, please call 617-242-5323 or visit

Water Conservation

Wasting water can add up quickly. On average, each person in the MWRA region uses about 60 gallons of water each day. More efficient water use can reduce the impact on the water supply and on your wallet. For ways to make your home and your habits more water efficient, contact the MWRA at 617-242-SAVE or visit our web site for tips on saving water indoors and in your backyard.


Water Conservation Works! On average, MWRA delivers 200 million gallons of water per day - over 120 million gallons less than it did in the 1980s.


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Where to Go for More Information

Web Sites and Telephone Numbers
Mass. Department of Conservation and Recreation
Source Water Assessment and Protection Reports
Information on Water Conservation

Public Meetings
MWRA Advisory Board
Water Supply Citizens Advisory Committee


Contact Us

If you have questions or comments about this report, please contact us. Call (617) 242-5323, e-mail, or write to: MWRA, Charlestown Navy Yard, Building 39, Boston, MA 02129.

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Your Community Letter:
Additional Information from Your City or Town Water Department

Read your community letter (PDF) for important information about your water from your city or town water department.

Fully Supplied Communities
These communities receive all of their drinking water from MWRA.
The water is treated at the Carroll Water Treatment Plant
and transmitted via the MetroWest Tunnel.
Lexington Nahant Somerville
Lynnfield W.D. Newton Southborough
Boston Norwood Stoneham
Brookline Quincy Swampscott
Chelsea Reading Waltham
Everett Revere Watertown
Framingham Saugus Weston

Partially Supplied Communities
These communities receive some of their drinking water from MWRA.
The MWRA water is treated at the Carroll Water Treatment Plant
and transmitted via the MetroWest Tunnel.
Canton Northborough Winchester
Residents of Peabody, Stoughton and Wellesley: please contact your local water department for your report.

Chicopee Valley Aqueduct Communities
These communities receive all of their drinking water from MWRA.
The water is treated at the Ware Disinfection Facility
and transmitted via the Chicopee Valley Aqueduct.


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Updated May 28, 2015