Table of Contents

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Providing Safe Drinking Water, From Watershed To Workplace

Testing All The Way To Your Home

Working To Keep Lead Out Of Drinking Water

Working To Reduce Lead Exposure

Information We All Need

Community Letter

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Providing Safe Drinking Water, From Watershed To Workplace

For over 175 years, water professionals have been working to build, maintain and operate the regional system that provides a reliable safe supply of drinking water to your community.

Today, MWRA professionals work to ensure the delivery of safe, pure water for your home, school or business, 24/7/365. Our staff collaborate with water departments in 53 communities, to ensure the continuing delivery of safe drinking water to 2.5 million people at their homes and businesses.

This annual MWRA drinking water quality report for 2023 provides information on how we work to provide high quality water to your community and to you.

MWRA staff work with staff at your community, the Department of Conservation and Recreation (DCR), and state and federal health professionals and regulators to provide and protect your drinking water. From the 400 square mile forest covered watersheds, to billions of gallons of water in the reservoirs, through treatment and thousands of miles of pipelines, and finally to your drinking water faucet, MWRA’s water experts conduct hundreds of thousands of tests on your water every year. Keeping the water safe is a continuous process, from watershed to water tap. MWRA’s staff across our entire organization carry out the work needed to protect your water.

Protected At The Source…

The water MWRA and your community provide to your home or business starts with our two pristine reservoirs in central Massachusetts — the Quabbin Reservoir, 65 miles from Boston, and the Wachusett Reservoir, 35 miles from Boston. Combined, these two reservoirs provide an average of 200 million gallons of pure, highly protected, high quality water each day. The Ware River provides additional water when needed.

The Quabbin and Wachusett watersheds—areas that drain water to the reservoirs—are naturally protected. More than 85% of the land is covered with forests and wetlands, which filter the rain and snow that enter the 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. Thisprocess helps to clean the water, but it also can dissolve and carry very small amounts of material into the reservoir. Minerals and rock do not typically cause problems in the water. Water can also transport contaminants, including naturally occurring minerals or radioactive material, and bacteria, viruses or other potential pathogens from human and animal activity that can cause illness. Testing results show that few contaminants are found in the reservoir water, and those few are in very small amounts well below EPA’s treatment standards.

MWRA and DCR work together to implement our nationally recognized watershed protection program. The Department of Environmental Protection’s (MassDEP) Source Water Assessment report for the Quabbin and Wachusett Reservoirs commended DCR and MWRA for our source water protection plans. The report states that our “watershed protection programs are very successful and greatly reduce the actual risk of contamination.” MWRA and DCR follow the report recommendations to maintain the pristine watershed areas and high quality source water. For more information on our source water, go to: www.mwra.com/sourcewater.html.

Water: Tested From The Source…

DCR biologists and environmental scientists sample the streams that feed the reservoirs to identify and resolve potential pollution sources, and to monitor water quality trends. MWRA and DCR scientists sample and analyze water in the reservoirs, and use specialized monitoring buoys to remotely and continuously monitor the reservoirs. Based on this information, MWRA operators can make key decisions on how to manage the Wachusett and Quabbin reservoirs. A key, initial test for reservoir water quality leaving the reservoirs is turbidity, or cloudiness. Turbidity refers to the amount of suspended particles in the water and can impair water disinfection. 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 2023, typical levels in the Wachusett Reservoir were 0.27 NTU, and highest level was only 0.49 NTU.

MWRA also tests water for potential disease-causing organisms, including fecal coliform bacteria, and parasites such as Giardia and Cryptosporidium, that can enter the water from animal or human waste. All test results for the reservoir water were well within state and federal testing and treatment standards. Learn more about MWRA test results for waterborne contaminants and their potential health impacts at: www.mwra.com.

How We Treat Your Water

MWRA’s John J. Carroll Water Treatment Plant in Marlborough provides state-of-the-art treatment and monitoring of your water. Our well trained and licensed operators add measured doses of treatment chemicals, and continuously monitor dozens of parameters. Treatment steps include:.

• Ozone, made from pure oxygen, disinfects the water, killing bacteria, viruses and other organisms, and improves water clarity and taste.
• Ultraviolet light (UV), a similar but more powerful form of natural disinfection than sunlight, renders pathogens non-infectious.
• Fluoride protects dental health.
• The water chemistry is adjusted to reduce corrosion of lead from home plumbing.
• Monochloramine (a compound of chlorine and ammonia), provides a mild and long-lasting disinfectant to protect the water as it travels through miles of pipelines to your home.

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Testing All The Way To Your Home

After we treat your water, MWRA operators and environmental quality staff test it as it leaves the treatment plant, and as it travels towards your home, as required by EPA and state regulations. MWRA sampling teams, and chemists and biologists at MWRA’s four laboratories conduct hundreds of thousands of tests per year for over 120 contaminants. A complete list is available on mwra.com. The results for 2023 are shown in the table below. They confirm the quality and safety of the water your community receives from MWRA.

Building Redundancy For Reliability

Maintaining the system and adding redundancy allows us to continue uninterrupted water delivery to your community, even if sections of our system need inspection, repair or rehabilitation.

MWRA’s engineers and geologists have completed environmental review and continue to work on design for two new tunnels north and south of Boston to provide reliable service to the entire region, as well as interim improvements to add resilience to the system. We also have major projects underway to rehabilitate the Weston Aqueduct Supply Main 3, a 60-inch pipe in Weston, Waltham, Belmont, Arlington and Medford, as well as a 48-inch pipe in Stoneham and Woburn. See www.mwra.com for more information.

Your community is investing in reliability as well. MWRA provides zero-interest loans to communities for pipeline rehabilitation and other water quality improvements. During 2023, we loaned $50 million to 17 communities for pipeline projects.

MWRA Water Test Results 2023
MWRA found only the contaminants listed here or discussed in this report. All are below EPA's Maximum Contaminant Levels (MCL).

Compound	Units	(MCL) Highest Level Allowed	(We Found) Detected Level-Average	Range of Detections	(MCLG) Ideal Goal	Violation	How It Gets in the Water
Barium	ppm	2	0.009	0.007 - 0.01	2	No	Common mineral in nature
Fluoride	ppm	4	0.633	ND-- 0.8	4	No	Additive for dental health
Nitrate^	ppm	10	0.32	ND - 0.62	10	No	Byproduct of disinfection
Total Trihalomethanes	ppb	80	24.2	5.95 - 37.6	NS	No	Byproduct of water disinfection
Halocetic Acids - 5	ppb	60	20.5	4.8 - 34.9	NS	No	Byproduct of water disinfection
Monochloramine	ppm	4-MRDL	1.98	0.04 - 3.7	4-MRDLG	No	Water disinfectant
Radium-226	ppb	5	0.82	0.82	0	No	Erosion of natural deposit
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 pCi/L=picocuries per liter ND=Not detected NS=no standard ^=As required by DEP, the maximum result is reported, not the average.

Working To Keep Lead Out Of Drinking Water

The water from MWRA’s reservoirs is free of lead. Lead can be found, however, in your home piping system—and in your home or business drinking water. Learn about the health impacts of lead and how to reduce exposure to this toxic metal.

Lead affects young children and may cause damage to the brain, slow growth and development, and create learning and behavior problems. Preventing lead exposure is particularly important if a pregnant woman or a child lives in your home or apartment. Lead can also impact the health of your entire family. While lead poisoning frequently comes from exposure to lead paint chips or dust, lead in drinking water can also contribute to total lead exposure

Lead and Copper Results, September 2023

	Range	90% Value	AL	Ideal Goal (MCLG)	# Homes Above AL/# Homes Tested
Lead (ppb)	0.08 - 965	10.8	15	0	36/595
Copper (ppb)	ND - 292	140	1300	1300	0/595
Key: AL = Action Level - The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow.

 

How Lead Enters Drinking Water
Lead in your home plumbing, or a lead service line, can contribute to elevated lead levels in the water you drink. MWRA’s water is lead-free when it leaves our reservoirs. Water mains that provide water to your community are made are mostly made of iron, steel or concrete, and do not add lead to the water. Lead can enter your tap water from your service line -the line that connects your home to the water main- if it is made of lead, lead solder used in plumbing, or from some older brass faucets.

Corrosion, or wearing away of lead-based materials, can add lead to tap water, especially if water sits in the pipes for a long time before it is used. MWRA’s licensed treatment operators adjust the water’s pH and buffering capacity by adding sodium carbonate and carbon dioxide to the water. This treatment makes water less corrosive and reduces leaching of lead into drinking water. Lead levels found in tests of tap water have dropped by nearly 90% since we made this treatment change in 1996. Learn more about lead in drinking water at www.mwra.com.

Important Lead Information From the EPA
If present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water comes 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 www.epa.gov/safewater/lead.

MWRA Meets Lead Standard in 2023

Under EPA and DEP rules, MWRA and your local water department are required to test local tap water each year. We collect samples from homes with lead service lines or lead solder. The EPA rule requires that 9 of 10 homes tested must have lead levels below the Action Level of 15 parts per billion (ppb).

This testing process can provide information on whether lead is corroding and mixing with the drinking water. It also provides communities and homeowners with information on how to reduce lead in their drinking water. The results do not reflect lead levels in all homes.

All sampling rounds over the past 21 years have been below the EPA Action Level. Nine out of ten homes were below 10.8 ppb - below the 15 ppb Action Level.

Six communities—Boston, Medford, Melrose, Revere, Quincy and Winthrop—exceeded the Action Level in September/October 2023. Your community letter below will provide you with local results and more information.

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Working To Reduce Lead Exposure

Lead Service Lines
A service line connects your home or building to the water main in the street. If yours is made of lead, it can be the main source of lead in your tap water. Older galvanized iron pipes with lead connectors (“goosenecks”) can also release lead. Lead service lines should be removed entirely to reduce lead in your drinking water.

Working To Replace Lead Service Lines
To help replace lead service lines, MWRA and its Advisory Board offer zero-interest loans to member communities. Each MWRA community can develop its own local plan, and many communities have already taken steps to remove lead service lines. Since 2016, MWRA has provided $41 million to 17 communities to replace lead service lines. Your local water department staff can help you find out if you have a lead service line, and provide help in replacing it. In some cases, an onsite check is necessary to determine the specific piping to your building.

Many communities have online maps. You can also see if your service line is made of lead by scratching the pipe near your water meter with a key or other metal object. Lead pipes will show a dull grey color, while copper pipes will not. For an online how-to guide, go to www.epa.gov/pyt.

Lead Testing in Schools
Children can consume much of their drinking water at school or childcare. Plumbing there may contain lead and contribute to lead exposure. MWRA, in coordination with MassDEP, provides no-cost lab analysis and technical assistance for schools and childcare centers in MWRA communities. Since 2016, MWRA’s laboratory staff have conducted over 40,000 tests for 576 schools and childcares in 44 communities. Results are available on the MassDEP website at: www.mass. gov/dep (search for “lead in schools”).

Results are available on the MassDEP website at: www.mass.gov/dep (search for “lead in schools”). You may also contact your local school or water department for results.

How to Test Your Drinking Water

If you are concerned about lead piping in your home, contact your local water department about testing for lead in your drinking water. MWRA also maintains a list of certified laboratories and sampling instructions on our website at www.mwra.com. You may also call MWRA at 617-242-5323.

Steps To Reduce Lead In Your Home Or Office

• Find out if you have a lead service line, and get it replaced.
• Let water run before using it - fresh water is better than stale.

• Any time water has not been used for more than 6 hours, run the faucet used for drinking water or cooking for at least one minute or until after the water runs cold. To save water, fill a pitcher with fresh water and place it 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 or young children.
• Remove loose lead solder and debris. Every few months, remove the aerator from each faucet and flush the pipes for 3 to 5 minutes.
• Be careful of places where you may find lead in or near your home. Paint, soil, dust and pottery may contain lead. Call the Massachusetts Department of Public Health at 1-800-532-9571 or 1-800-424-LEAD for information on lead and health impacts.

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Information We All Need

EPA Information On Bottled Water And Tap 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, MassDEP and the EPA prescribe regulations which limit the amount of certain contaminants in water provided by public water systems. The U.S. Food and Drug Administration (FDA) and the Massachusetts Department of Public Health (MDPH) regulations establish limits for contaminants in bottled water, which must provide the same protection for public health.

MWRA Monitoring for PFAS

PFAS, or per- and polyfluoralkyl substances, used since the 1940’s for many purposes from stain and water proofing to firefighting, continue to be a national concern. Due to our well protected sources, tests of MWRA water show only trace amounts of these compounds, well below the state PFAS6 standard of 20 parts per trillion. MWRA also meets the new EPA standards announced in April 2024. See www.mwra.com for more details.

Important Health Information: 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).

Working With Your Community To Test Your Water

MWRA works with local water department staff to sample and test 300-500 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. If total coliform is detected in more than 5% of water samples in a month, the water system is required to investigate the possible source and fix any identified problems. If a water sample does test positive, our laboratory staff run a more specific test for E. coli, which is a bacteria found in human and animal fecal waste and may cause illness. If your community was required to do an investigation, or found E. coli, it will be in the letter from your community.

Important Research For New Regulations

MWRA works with EPA and health research organizations to help define new national drinking water standards by collecting data on water contaminants that are not yet regulated. Very few of these potential contaminants are found in MWRA water due to our source water protection efforts. Detailed information on testing for unregulated contaminants, as well as data on PFAS, disinfection by-products, Giardia and Cryptosporidium, and other contaminants can be found at mwra.com, search for UCMR.

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Your Community Letter:

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Updated June 21, 2024