Table of Contents

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).

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

2010-2023 (PDF)

1992-2009 (PDF)

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.

For more information about lead, including summary level information about the substantial decrease in lead levels after MWRA began operating corrosion control in 1996, visit our Lead Tests for Drinking Water page.

Results Not Part of the Regulatory Sampling

The following sections provide residential lead results that were not part of the Lead and Copper Rule sampling described above. All of the results below were communicated to homeowners:

Massachusetts Department of Public Health (MDPH) Samples: 

These results below were from samples collected by the MDPH Lead Poisoning Prevention Program in homes.  The MDPH staff visit homes that have a child who has elevated lead levels, helping the family investigate possible sources of lead, such as lead paint or lead dust, as these are the typical causes of lead poisoning. Beginning in 2016, MDPH began including drinking water testing as part of the investigations.  Two samples from the kitchen sink are collected – one a first draw after the water is not run overnight, and one after the water has been run for 30 seconds.  MWRA reports the results back to MDPH once they are analyzed at MWRA’s laboratory. MDPH then provides the results to the residents, preserving the required confidentiality under federal health privacy laws. As the results show, the levels of lead in these homes has generally been very low, with only two of the nearly 230 samples over the Action Level.

Investigation Samples:

These are samples taken to evaluate water quality in a home or building, usually initiated by the local water department as a result of a customer  inquiry or complaint.  Water quality parameters are evaluated depending on the specific issue of concern, including an analysis for lead if appropriate. Only investigations which included an analysis for lead are reported here.

Lead Request Samples:

These are samples from homes where the local water department specifically wanted to test for lead, even though the home may not have a lead service line, e.g., following a customer request.  

Lead Service Line Samples: 

Service lines —piping that connects a building to the water main, may be made of lead, and thus may contribute to lead levels in drinking water. Below are the results of samples taken from homes that have had all or a portion of their lead service lines (LSLs) replaced by the local water department. If two samples were taken from one home, those are listed as 1 and 1A, the first sample is representative of the water in the lead service line, while the second sample is usually one that is taken after the water is flushed. The disruption of the LSL may contribute to elevated, but temporary, lead levels in the drinking water.

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

Related Pages

Back to "What You Need To Know About Lead in Tap Water" page

Annual Water Test Results

Monthly Water Test Results

All Water Tests