Excessive amounts of lead were again found in a recent survey of Boston's tap water, the city's water utility said Thursday.
The Boston Water and Sewer Commission is required to collect samples of tap water from homes around Boston, and the latest round found lead levels at higher than 17.4 parts per billion, the threshold set by federal and state environmental agencies, the commission said.
That means the utility will increase monitoring, remove lead service lines in its system and reach out to the public about the danger that lead presents to people.
Excessive lead was found in Boston homes last year as well.
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The metal can cause damage to the brain, kidneys and red blood cells, and is especially risky for children and, through pregnant mothers, fetuses, whose physical and mental development can be stunted.
Lead enters tap water through service pipes and household plumbing that may contain it -- there's none in the water system from the reservoirs through the state and city water mains, the Boston Water and Sewer Commission.
The agency recommends that anyone who gets drinking water from faucets that come from lead-containing pipes flush the water for 30 seconds to 2 minutes if it's gone unused for several hours. The agency also offers up to $4,000 to help property owners remove their lead service lines -- it's helped swap out more than 400 lines so far already.
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You can see if your home is known or suspected to have a lead line by visiting this website, or call 617-989-7888 for more information.