To monitor lead levels, MWRA and your local water department test tap water in up to twenty-five homes in each community.
Lead results for the entire system and for each community are compiled by MWRA, with an average of 440 samples taken for the entire system. The regulations require that a system our size – serving over 2 million people – take only 100 samples. New York City, with around 5 times as many customers, takes only 100 samples.
We have agreed with our state regulators at the Department of Environmental Protection to uniformly sample more than 4 times as many homes across the service area to get a better idea of how our corrosion control treatment is working.
But not just any homes are sampled. Under Environmental Protection Agency regulations, homes that are likely to have high lead levels - usually older homes likely to have lead service lines or lead solder – must be tested. Also, only first flush samples, water most likely to have lead, are sampled. The EPA rule requires that 90% of these sampled homes must have lead levels below the Action Level of 15 parts per billion (ppb).
Lead levels in sampled high-risk homes have dropped steadily since 1992, with the average dropping nearly 90%. Also, the proportion of samples has also changed over time.
Lead Levels in Sampled Highest Risk Homes Have Dropped Steadily Since 1992
As the pie charts above show, the number of worst case homes that have lead levels that are less than 1 ppb and 5 ppb has increased dramatically, as well over 80% of the samples are now less than 5 ppb.
Lead and Copper in Drinking Water
Exposure to lead may have significant health impacts, particularly for young children. Copper may also be of concern to persons with specific health issues. Drinking water though is rarely a significant source of these contaminants. MWRA maintains programs in addition to required water monitoring to ensure the safety of the water you drink in compliance with the Lead and Copper Rule.
Our goal and your goal should be to have lead results as low as possible. Residents and communities are urged to take corrective actions if results at a home or business are above the lead Action Level (AL) of 15 ug/l (or parts per billion-ppb) or if they exceed the AL for copper of 1300 ug/l. For more information about actions that can reduce lead levels, visit: What You Need to Know About Lead In Tap Water.
Plumbing components including lead service lines (LSLs), goosenecks, solder, and fixtures may release lead to the water, while copper may enter drinking water through pipes. MWRA monitors and adjusts water chemistry to prevent corrosion in a building’s water delivery systems. MWRA also works with the communities receiving our water to ensure that all regulatory testing is carried out as required to ensure the safety of residents and businesses.
The following sections provide information on the results of required regulatory testing of drinking water for lead, and non-regulatory testing to assess the water in local distribution systems. These additional analyses, not required in State regulations, help identify potential problems related to local home plumbing, the removal of lead service lines, and other factors upon request. Results of all tests are shown below, with specific addresses removed to protect privacy.
MWRA also collaborates with the Massachusetts Department of Environmental Protection (DEP) to analyze water samples from schools and childcare facilities in the communities we serve. Samples are also analyzed for compliance with the Lead and Copper Rule requirements, and for the Lead Contamination and Control Act (LCCA).
Copper in Drinking Water
Copper is an essential nutrient, but at high levels can have adverse health effects. MWRA water does not contain copper; however copper from plumbing in a home or building may leach into drinking water. MWRA’s corrosion control treatment adjusts pH and alkalinity of the water to limit the release of copper and other metals into the water.
MWRA and your local water department analyze local drinking water annually or biannually to ensure that both copper and lead, also found in home piping, remain below required regulatory limits. Under the Lead and Copper Rule (LCR), the 90th percentile of all samples taken across the distribution system must have copper levels less than 1300 parts per billion (ppb), the Action Level (AL) for copper in drinking water. Copper levels in the MWRA water community testing are always below the Action Level. Results in 2023 were well below the Action Level, at 140 ppb.
Information about MWRA and community test results is published in MWRA’s Annual Water Quality Report. Information on copper levels in reservoir and treated water is available in MWRA’s monthly Water Quality Update on that site.
Copper levels above the Action Level may contribute to health impacts in individuals sensitive to this metal, including individuals with Wilson’s Disease. More information on copper and related health effects may be found here.
Regulatory Lead and Copper Rule Results
All public community water systems are required to test drinking water in homes and schools each year, or more often, based on the Lead and Copper Rule. Water Departments take samples in multiple homes at risk for lead in drinking water, e.g., those with lead service lines, lead solder or other factors. The 90th percentile of all samples taken in a community must be below the Action Level (AL) for lead of 15 parts per billion (ppb) and for copper of 1300 ppb. Communities that exceed the AL must test drinking water twice each year until their results for both contaminants are below the AL, as well as provide additional public education on the health effects of lead and begin a program of replacing lead service lines.
Provided below are the results from lead testing in communities receiving all of their drinking water from MWRA. The documents below link together the information from samples taken and tested in the first (“.01”) and second (“.02”) sampling periods (typically starting in March and September of each year). Individual samples which exceed the lead Action Level (AL) of 15 ppb (parts per billion) are shown in red. The specific residential addresses where samples were taken are not shown to protect resident’s privacy. Individual results for each address were provided to the owner/resident.
This testing is carried out in collaboration with the local Water Department for each community.
Lead and Copper Rule Test Results |
|---|
| 2010-2024 |
| 1992-2009 |
The individual results shown in these documents provide a “snapshot” of what is happening in a specific house after the water has not been run (i.e., the water is “stagnant”) for at least six hours. The sampling protocol is designed to evaluate the effectiveness of the corrosion control treatment measures MWRA implements to prevent lead and copper from entering the water. The results shown here do not necessarily provide real information about the water a resident would typically drink (most consumers would not drink stagnant water).
As required under the Lead and Copper Rule, MWRA samples only the homes most likely to have lead-older homes that might have a lead service line, lead solder in piping, or fixtures containing lead.
If you are interested in having your water tested, a list of private labs is available on our DEP Certfied Labs page.
Lead Testing in Schools
Starting on April 1, 2016 MWRA, in coordination with the Department of Environmental Protection (DEP), began providing no cost lab analysis and technical assistance for schools and day care centers across all of MWRA’s water communities. Almost all MWRA communities participated in the program, and sample tests and assistance are still ongoing. As of April 30, 2020 MWRA's Laboratory conducted over 37,000 tests from 478 schools in 44 communities. MWRA reported all school results to the DEP. Most of these results are available on the DEP website:
DEP: Search for Lead and Copper Drinking Water Results in Schools/Childcare
DEP: More information on programs related to lead in schools
Some results also may be available through your local community website, DPW, or school department.
MWRA Contact
If you have any questions, please contact Beverly.Anderson@mwra.com