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2002 Drinking Water Quality Test Results
For our Metro Boston/MetroWest Customers

(en español)

Questions and Answers

Q: How does MWRA protect my water?

A: MDC rangers, in partnership with MWRA, patrol the Quabbin and Wachusett Reservoirs and incoming streams within the watershed every day. The water is tested daily for many parameters, and many more are performed weekly and monthly.

Operators monitor the water that comes to your community 24 hours a day, 365 days a year.

Also, in response to any heightened alerts from the office of homeland security, MWRA has taken extra security steps, including locking down operational facilities, adding facility checks, increasing water quality monitoring and many other security measures.


Q: How would I know about a problem with the water supply?

A: MWRA and your local water department keep close watch on the water supply. The law requires that you be told if there is a problem with your water. You would get the news by radio, television and newspapers, from MWRA, your local health departments and the state Departments of Public Health (DPH) and Environmental Protection (DEP).

Q: What can I do to reduce exposure to lead in drinking water?

A: Be careful of places you may find lead in or near your home. Paint, soil, dust and some pottery may contain lead.

Run the tap until the water feels cold. Then fill a pitcher with water and place in the refrigerator for future use.

Never use hot water from the faucet for drinking or cooking – especially when making baby formula or other food for infants.

As your local water department if there are lead service pipes leading to your home.

Test your tap water. Contact MWRA for more tops and a lit of certified labs.

Call the Department of Public Health at (617) 284-8400 if you have questions.

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Q: My water is discolored or cloudy once in a while. Can I drink it?

A: Water is piped under pressure throughout the system. Sometimes air can become trapped in the water, causing cloudiness. This is only temporary and the water clears up in a short time.

Rust from old iron pipes can cause red, brown or yellow water. Changes in water speed or direction in your local pipes can cause rust to be carried along.

This can happen when the valves are being repaired, flushed or tested, or fire hydrants are in use. Wait until the water is clear before doing laundry to avoid staining clothes. You can safely drink, cook with or bathe in this water.

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Q: How does MWRA protect my water?

A: MDC rangers, in partnership with MWRA, patrol the Quabbin and Wachusett Reservoirs and incoming streams within the watershed every day. The water is tested daily for many parameters and many more tests are performed weekly and monthly. Operators monitor the water that comes into your home 24 hours a day, 365 days a year.

Also, in response to any heightened alerts from the Department of Homeland Security, MWRA has taken extra security steps, including locking down operational facilities, adding facility checks, increasing water quality monitoring and many other security measures.

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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 28.9 mg/l (about 7 mg per glass).

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This report provides information on:
(click the links to jump to each section)
Where your water comes from
Improvements to the system
Test results
How your water is treated
Information about lead
Other helpful information about your drinking water
(click the links to jump to each section)
A letter from our Executive Director
Questions and answers
Facts about sodium
New EPA Regulations
Important Information from EPA and DEP About...
Contaminants in Bottled Water and Tap Water
Drinking Water and People with Weakened Immune Systems
Notice on Norumbega Reservoir


A letter from our Executive Director

June 1, 2003

Massachusetts Water Resources Authority
Charlestown Navy Yard • 100 First Avenue • Boston, MA 02129

Dear Customer,

I am pleased to send you this annual report on your drinking water quality. This report is prepared with the help of your local water and health department and it describes how we treat and deliver the tap water that reaches your home. It also includes the test results for 2002 - and the news is good. For example, in 2002, MWRA met the federal Lead and Copper Rule for the first time.

I also want you to know that we are nearing completion of several facilities designed to modernize our water system. The new water tunnel, treatment plant and storage projects to improve system reliability and security are the biggest advances in the regional water supply in many decades. We have made great progress on these programs over the last year and we will begin a two-year startup of the new water system this fall. We will be working closely with local water departments to ensure continuous operations as these new facilities are brought on-line.

I hope you will take a few moments to read this important report. MWRA has great confidence in the water we deliver to over 2 million customers and we hope that this report will give you the same confidence. Please contact us if you have any questions or comments about your water quality, or any of MWRA’s programs.

Frederick A. Laskey
Executive Director

Where does your water come from?

water map (small) MWRA Water Improvement Program Map

(click map for a larger view)

The MWRA supplies wholesale water to local water departments in 40 cities and towns of greater Boston and MetroWest and three in Western Massachusetts. This water comes from Quabbin Reservoir, about 65 miles west of Boston, and Wachusett Reservoir, about 35 miles west of Boston. The reservoirs provide about 250 million gallons of high quality water to consumers each day. Water from the Ware River, located between these two reservoirs, can also add to the supply at times.

Rain and snow falling on the watersheds - protected land around the reservoirs - turn into streams that flow to the reservoirs. Water comes in contact with soil, rock, plants, and other material as it follows nature’s path to the reservoirs. While this process helps clean the water, it can also dissolve and carry very small amounts of material into the reservoir. Minerals from soil and rock, including low levels of natural radioactive materials, do not usually cause problems in the water. But water can also transport contaminants from human and animal activity. These can include bacteria, viruses, pesticides, and fertilizers - some of which can cause illness. The test results in this report show that these are not a problem in the reservoirs' watersheds.

Quabbin and Wachusett watersheds are protected naturally, as over 85% of the watersheds are covered in forest and wetlands. About 75% of the total watershed land cannot be built on. The natural undeveloped watersheds help to keep MWRA water clean and clear. Also to ensure safety, the streams and the reservoirs are tested often and the watersheds patrolled daily by the Metropolitan District Commission (MDC).

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Major Improvements Underway

MWRA’s Integrated Water Supply Improvement program is a 10-year, $1.7 billion series of projects to protect watersheds, and build new water treatment and transmission facilities. It is more than halfway complete and scheduled to be on-line by 2004. Be on the lookout for more information on water system improvements as new facilities come on-line over the next year and a half. The major components are:

Walnut Hill Water Treatment Plant -
We are over 60% done with a new water treatment plant in Marlborough that will begin operating in December 2004. It will consolidate all treatment steps into one plant, and will use ozone rather than chlorine for primary disinfection. Ozone provides stronger disinfection against pathogens, such as Cryptosporidium, and will reduce levels of disinfection byproducts.

MetroWest Water Supply Tunnel -
We are 99% done with a 17-mile-long tunnel to connect the new treatment plant at Walnut Hill to the greater Boston area. This will become the main transmission line with the aging Hultman Aqueduct as the back-up. The new tunnel is fully bored and lining is complete. The tunnel will be put into service in Fall 2003.

Water Storage Tanks -
We have been building covered storage tanks to replace small open reservoirs near cities and towns. This lessens the risk that contaminants will get into your tap water and is required by the State Department of Environmental Protection (DEP) rules. Three of these tanks in Stoneham, Ludlow, and Weston are now complete. Construction of a fourth in Weston will be placed in service in Fall 2003 to replace the Norumbega Reservoir in Weston.

Pipeline Rehabilitation - MWRA and local water departments are working to replace, or clean and reline hundreds of miles of both MWRA and locally owned older pipes.

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Water Test Results

Before treatment - Your water is tested each step of the way – from the reservoir to the tap. We test the water as it leaves the reservoir to see how well our watershed protection is working. Test results show few contaminants are found in the reservoir water. Those few that are found are present in very small amounts, well below EPA’s standards.

Turbidity (or cloudiness of water) is one measure of overall water quality. Wachusett Reservoir water is below both EPA’s standard of 5.0 NTU (Nephelometric Turbidity Units) and the stricter Massachusetts standard of 1.0 NTU. Typical levels are 0.3 NTU and the highest level found at Wachusett was 0.84 NTU.

MWRA also tests reservoir water for pathogens - such as fecal coliform bacteria, viruses, and the parasites Cryptosporidium and Giardia. They can enter the water from animal or human waste. All test results were well within state and federal standards. No Cryptosporidium or Giardia was found in weekly samples of water at the intake.

After treatment - EPA and State regulations also require many water quality tests after treatment to check the water you are drinking. MWRA follows – and even goes beyond – these tests. We conduct thousands of tests per year. This allows us to better monitor your water

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Reservoir Water Test Results – After Treatment

  • What does this table tell me? EPA requires that we test for over 120 contaminants. MWRA found only those noted in this report.

  • What is the bottom line? The water quality is excellent. All of the levels are well below EPA's allowable limits.
(MCL) - Highest Level Allowed
(We Found)
Detected Level
Range of Detection
Ideal Goal

Is the level in violation?

How It Gets in the Water
Common mineral in water
Additive for dental health
Natural deposits, stormwater/ fertilizer runoff
Natural deposits, stormwater/ fertilizer runoff
Erosion of natural mineral deposits


Erosion of natural mineral deposits
Total Trihalomethanes
Byproducts of water disinfection
Halaocetic Acids-5
Byproducts of water disinfection

MCL = Maximum Contaminant Level - the highest threshold of 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.
PPM = parts per million (about one drop in one 55-gallon barrel of water).
ppb = parts per billion (about one drop in 1,000 barrels of water).
pCi/L = picoCuries per liter. *(EPA considers 50 pCi/l to be the level of concern for beta particles.
Avg. = average

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How is our water treated?

MWRA’s licensed operators treat water at a number of places in the system. The first treatment step is the primary disinfection of reservoir water. We carefully add measured doses of chlorine to the water to kill any pathogens (germs) that may be present in the water.

Next, the water chemistry is adjusted to reduce corrosion of lead and copper from home plumbing. Fluoride is then added to reduce cavities. Last, we add chloramine, a mild and long lasting disinfectant combining chlorine and ammonia, which protects the water while it is in the local pipelines.

Tests in community pipes

MWRA and local water departments work together to test water all the way to the tap. We test 300 to 500 samples of water in the city and town systems each week for total coliform bacteria. Total coliform bacteria can come from the intestines of warm-blooded animals, and they also can be found in soil, on plants, and other places. Most of the time, these bacteria are not harmful to humans. 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 given month may be positive for total coliform. If a water sample tests positive for total coliform, we run more specific tests for E.coli, which is a pathogen found in human and animal fecal waste that can cause illness.

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Total Coliform Results

Highest % of positive samples and month
Violations of EPA's 5% limit
0.37% (July)
1.33% (Aug., Sept.)
4.35% (July)
1.05 (March)
1.82% (April, June)
2.33% (September)
20% (August)
8.7% (July)
MWRA transmission line
1.96% (August)
*NOTE: Only two of these communities exceeded the EPA standard. In 15 follow-up tests, no E.coli was found. For more information on total coliform results and actions taken for Southborough and Weston, please read their community letters.

How did we do in 2002?

The table above reports test results from 30 communities that receive all of their water from MWRA. Total coliform were found in 8 communities.

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New EPA Regulations

MWRA has been working with EPA and other researchers to define new national drinking water rules by testing for compounds which are not regulated. Our results will be used with those of other water suppliers to help EPA set regulations for these compounds if they are necessary. MWRA is also participating with Tufts University on a nationally-funded study on Cryptosporidium.

Ongoing Research for New Regulations

Measurement Units
1998-1999 Results
Chloral Hydrate
Cyanogen Chloride
Total Organic Halides
mg Cl/l


cysts per 100L
PPM = parts per million
mg Cl/l = milligrams of chloride per liter
MPN/L = most probable number per liter
* results from 2002
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Lead in tap water

MWRA water is lead-free when it leaves the reservoirs. MWRA and local pipes that carry the water to your community are made mostly of iron and steel, and do not add lead to water. However, lead can get into tap water through pipes in the home, lead solder used in plumbing, and some brass fixtures. Corrosion or wearing away of lead-based materials can add lead to tap water, especially if water sits for a long time in the pipes before use.

Under EPA rules, each year MWRA and your local water department must test tap water in a sample of homes that are likely to have high lead levels. These are usually homes with lead service lines or lead solder. The EPA rule requires that 9 out of 10, or 90%, of the sampled homes must have lead levels below the Action Level of 15 parts per billion (ppb).

Good news on lead - In 1996, MWRA began to treat the water to make it less likely that lead would enter tap water from pipes. Since then, the effort to help control lead corrosion has continued, and now MWRA meets the Lead and Copper Rule. Lead levels in sampled worst case homes have steadily dropped since 1992. Results for September 2002 are shown in the table, with an overall test score of 91.9%, now meeting the standard of 90%. Nine of ten houses were below 11.3 ppb, which is below the Action Level of 15 ppb. MWRA once again met the Copper Action Level.

90th % Lead Levels 92-02

Important Lead Information from EPA

Infants and young children are typically more vulnerable to lead in drinking water than the general population. It is possible that lead levels at your home may be higher than those at other homes in the community as a result of materials used in your home's plumbing. If you are concerned about elevated lead levels in your home's water, you may wish to have your water tested and flush your tap for 30 seconds to 2 minutes before using tap water. Additional information is available from the Safe Drinking Water Hotline: (800) 426-4791.

Lead and Copper Results for 2002

90% Value
(Target) Action Level
(Ideal Goal)

# homes that failed AL / # homes tested

0 - 62 ppb
11.3 ppb
15 ppb
0 - 1.1 PPM
0.12 PPM
1.3 PPM

Action Level (AL) = The concentration of a contaminant, which, if exceeded, triggers treatment or other requirements which a water system must follow.

Maximum Contaminant Goal (MCLG)= The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.

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Important information from EPA and DEP about...

Contaminants in Bottled Water and Tap Water - Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contamination. 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 EPA’s Safe Drinking Water Hotline (1-800-426-4791).

In order to ensure that tap water is safe to drink, Massachusetts DEP and EPA prescribe regulations that 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 that must provide the same protection for public health.

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Drinking Water and People with Weakened Immune Systems -
Some people may be more vulnerable to contaminants in drinking water than is 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 disorder, 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 Safe Drinking Water Hotline (1-800-426-4791).

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Notice on Norumbega Reservoir - Until the new covered storage tank is completed, the Massachusetts DEP requires that MWRA publish the following notice: “Inadequately treated water may contain disease-causing organisms. These organisms include bacteria, viruses, and parasites which can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.“ The new tank will come on-line in two steps in Fall 2003 and Spring 2004. Click here for more information.

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Where to Go for Further Information

Health Issues
Massachusetts Department of Public Health (DPH)
Tel.:   (617) 624-6000
US Centers for Disease Control & Prevention (CDC)
Tel.:  (800) 311-3435
List of State Certified Water Quality Testing Labs
Tel.:  (617) 242-5323
Water System and Regulations
Massachusetts Water Resources Authority (MWRA)
Tel.:  (617) 242-5323
Massachusetts Department of Environmental Protection www.mass.gov/dep
Tel.:  (617) 292-5500
Metropolitan District Commission www.mass.gov/mdc/water.htm
Tel.:   (617) 242-5323
Source Water Assessment and Protection Report www.mwra.com/sourcewater.htm
Tel.:  (617) 242-5323
Public Meetings
MWRA Board of Directors
Tel.:  (617) 788-1117
MWRA Advisory Board
Tel.:  (617) 742-7561
Water Supply Citizens Advisory Committee
Tel.:  (413) 586-8861
Click here for MWRA's monthly water quality report.

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Your Community Test Results

In the list below, click on your city or town for a message from your local water service provider. If you live in a partially-supplied community - marked with an asterisk (*), your city or town's results may differ from MWRA's. Your community's test results will be included in your community's letter.



(Please note: Peabody, Wellesley and Stoughton are partially-supplied communities. Their reports will be linked to this site as soon as possbile.
Chicopee Valley Aqueduct System Communities (Chicopee, South Hadley FD#1 and Wilbraham), click here for your full report


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Additional Versions of this Report are Available

If you would like to request a Spanish-language version of this report, click here.

For a large-type version of this report, please email your request to Joshua Das, Project Manager, Public Health: JoshuaDas@mwra.state.ma.us

Share Your Thoughts
Your comments on last year's report helped us to improve it. To reduce costs, we've shortened the report this year, with each copy costing only 25 cents to print and mail. Give us a call, send us a letter or email, and let us know what you think.

Massachusetts Water Resources Authority
100 First Avenue
Boston, MA 02129
attn: Joshua Das, Project Manager - Public Health

email: JoshuaDas@mwra.state.ma.us
MWRA Water Quality Hotline: (617) 242-5323

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