MWRA's Drinking Water Test Results for 2008
FOR METRO BOSTON/METRO WEST COMMUNTIES
This report is required under the federal Safe Drinking Water Act Public Law 104-12, Section 1414 (C), PWS ID #6000000.
This report describes how we treat, test and deliver tap water to your home.
The Massachusetts Water Resources Authority and your local water department test up to 500 samples each week, and test for over 120 contaminants each year.
A MESSAGE FROM MWRA EXECUTIVE DIRECTOR FRED LASKEY
WHERE DOES YOUR WATER COME FROM?
Your water comes from the Quabbin Reservoir, about 65 miles west of Boston, and the Wachusett Reservoir, about 35 miles west of Boston. These reservoirs supply wholesale water to local water departments in 50 communities, 44 in greater Boston and MetroWest, three in western Massachusetts, and serves as a back-up supply for three others. The two reservoirs combined supplied about 206 million gallons a day of high quality water to consumers in 2008.
Quabbin and Wachusett watersheds are protected naturally with over 85% of the watersheds 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
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, viruses, and fertilizers - some of which can cause illness. The test data in this report show
The Department of Environmental Protection (DEP) has prepared a Source Water Assessment Program report for the Quabbin and Wachusett
MAP OF THE MWRA WATER SYSTEM
HOW YOUR WATER IS TREATED
From the Reservoir to Your Home - Water Treatment Steps
The water you drink is treated at the John J. Carroll Water Treatment Plant in Marlborough. The first treatment step is disinfection of reservoir water. MWRA’s licensed treatment operators carefully add measured doses of ozone gas bubbles to the water to kill any pathogens (germs) that may be present in the water.
IMPROVEMENTS TO THE WATER SYSTEM
MWRA’s Improvements to the Water Supply
Over the last ten years, in addition to the
MWRA and its partner communities will continue to make necessary improvements to ensure high quality water is delivered directly to the customer’s tap. One high priority is rehabbing older pipes within the extensive pipe network. MWRA is upgrading its own pipes, as well as providing zero-interest loans to help communities improve their older pipes. To save money and limit traffic and
On average, each person uses about 65 gallons of water each day. There are many simple ways you can conserve water and lower your bills, including: fixing leaks, installing low-flush toilets and low-flow shower heads, or minimizing
Demand has dropped dramatically and water usage is lower than it has been in over 40 years. Still, there is more work to be done to conserve this precious resource. To find out more, contact the MWRA at 617-242-SAVE or visit our web site for tips on saving water indoors and in your backyard.
Tests Before Treatment
We test the water as it leaves the reservoir to see how well protected our watersheds are. Test results show few contaminants are found in the reservoir. The few that are found are in very small amounts, well below EPA’s standards. Turbidity (or cloudiness of water) is one measure of overall water quality. Typical levels at the Wachusett Reservoir are 0.3 NTU (Nephelometric Turbidity Units). In 2008, turbidity was always below EPA’s standard of 5.0 NTU. It was also below the stricter Massachusetts standard of 1.0 NTU over 99.99% of this time, with the highest level at 1.17 NTU. This did not interfere with effective disinfection. MWRA also tests reservoir water for pathogens – such as fecal coliform, bacteria, viruses, Cryptosporidium, 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.
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, these bacteria 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 for total coliform. If a water sample tests positive for total coliform, we run more specific tests for E.coli. E.coli is a bacteria found in human and animal fecal waste and may cause illness.
Tests After Treatment
EPA and state regulations also require many water quality tests after treatment to check the water you are drinking. MWRA conducts tens of thousands of tests per year on over 120 contaminants. The bottom line is that the water quality is excellent. All of the levels are below EPA’s allowable limits. A complete list of potential contaminants that we test for is posted on our website.
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 the water.
However, lead can get into tap water through pipes in your home, your lead service line, lead solder used in plumbing, and some brass fixtures.
What is MWRA doing to lower levels? What can I do?
In 1996, MWRA began adding sodium carbonate and carbon dioxide to adjust the water's pH and buffering capacity. This change has made the water less corrosive, thereby reducing the leaching of lead into drinking water. Lead levels found in sample tests of tap water have dropped by over 80 percent since this treatment
MWRA Meets Lead Standard in 2008
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).
Lead levels in sampled worst case homes have dramatically dropped since 1992. Over the last several years, the results have been below the EPA standard, including the last 10 sampling rounds. Results for September 2008 are shown in the table. 9 of 10 houses were below 8.1 ppb, which is below the Action Level of 15 ppb. Some communities had more than one home test above the Action Level. If you live in one of these communities, your town letter will provide you with more information.
What can I do to reduce exposure to lead in drinking water?
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 www.epa.gov/safewater/lead.
IMPORTANT INFORMATION FROM EPA AND DEP
Contaminants in 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, the Massachusetts DEP and EPA prescribe regulations which limit the amount of certain contaminants in water provided by public water systems. 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.
Research and New Regulations
MWRA has been working with EPA and other researchers to define new national drinking water standards by testing for contaminants that are not regulated. Our results will be used with those of other water suppliers to help EPA set regulations if they are necessary. MWRA is also participating with Tufts University on a nationally-funded study testing for Cryptosporidium and Giardia.
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
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Updated December 15, 2009