Lynn Thorp, national campaigns director at Clean Water Action, a group that advocates for safe, affordable water, applauded the move. “This is a leadership move, and it shows that it can be done,” Thorp said. “There are other places that have worked toward removing all lead service lines. But I’m not aware of anything of this scale.”

Service lines connect water mains below the street to homes and businesses. Lead lines are no longer installed because they can leach harmful levels of lead into the water, but they were commonly used decades ago in many parts of the country.

The Massachusetts Water Resources Authority is launching a $100 million interest-free loan program to help cities and towns cover the cost of replacing 28,000 aging water service lines made with lead that threaten to contaminate drinking water in dozens of communities.


Removing old lines is a daunting task, but some individual communities have succeeded in replacing all lead service lines. The East Bay Municipal Utility District in California replaced its lead service lines in the 1990s. The city of Lansing, Mich., expects to have all of its replaced by next year.

There has been increased public attention to water quality because of the ongoing crisis in Flint, Mich. That community’s drinking water was contaminated because the city switched its water supply and did not use anticorrosive chemicals that could have prevented lead from leaching into the water.

Under the new initiative in Massachusetts, the water authority would provide funding to cities and towns for eligible lead service line replacement projects in 47 communities it supplies. The communities would have 10 years at zero interest to pay back the MWRA.

Communities would be able to develop their own programs for replacing lead service lines. Some communities may ask owners of properties connected to the lines to chip in to pay for the work. And officials acknowledged that the installation could lead to higher water rates.


Officials said details of the program are still being ironed out, but they expect it will launch fully within the coming months.

“I am proud that Massachusetts is taking proactive measures to ensure that residents have continued access to clean drinking water,” Governor Charlie Baker said in a statement.

“The loans being provided by the Massachusetts Water Resources Authority will allow communities to take the steps necessary to modernize their drinking water infrastructure, and keep Massachusetts’ families safe and healthy,” he added.

Water systems typically alter the chemistry of the water they distribute to make it less corrosive and less likely to cause lead to leach from pipes into the water. The process has generally been effective at reducing lead levels.

But advocates for years have said the only way to ensure that water is safe is to remove all lead-based plumbing materials that water travels through.

MWRA officials say the water flowing from its reservoirs and through its water mains is virtually lead-free, but water can be contaminated after it leaves the main and before it flows from people’s faucets.

Officials said the new financing program will allow them to greatly accelerate progress on their years-long replacement efforts and could also be a helpful head start should the Flint crisis prompt regulatory changes that mandate water systems replace lead service lines.


“Clean, safe drinking water for the residents of the Commonwealth is a priority,” Matthew Beaton, the state’s energy and environmental affairs secretary and chairman of the MWRA board, said in a statement.

Small amounts of lead in adults are not thought to be harmful, but even low levels of lead can be dangerous to infants and children.

The MWRA is a quasipublic agency that acts as a wholesaler of water, reaching about 2.2 million people and 5,500 industrial users, primarily in Eastern Massachusetts.

Over the years, MWRA communities have seen dramatic reductions in the number of buildings where water has been found to have elevated lead levels. But tests still find some lead concentrations are too high.

Lead service lines are believed to be at least partially responsible for poor test results, though now-banned lead plumbing materials installed inside individual homes can also be a factor.

The authority estimates that about 28,000 buildings are connected to lead service lines. That’s about 5.6 percent of the 500,000 service lines within the area the MWRA serves. However, the agency is surveying communities to get a more accurate count of how many lead service lines exist.

Replacing a lead service line typically costs between $3,000 and $5,000, officials said. That translates into a total cost of between $84 million and $140 million to replace the estimated number of lines. But officials believe the $100 million program will be enough.

To cover the interest on the debt that the authority will incur, water bills may have to be hiked. But officials from both the authority and the MWRA Advisory Board, which serves as the agency’s watchdog, said property owners would notice only a minimal increase, if they notice at all.


In Boston alone, there are more than 3,500 lead service lines, according to city records.

“This program will help ensure that all residents of MWRA communities will continue to have safe drinking water, regardless of their ZIP code or the age of their home,” Mayor Martin J. Walsh said in a statement.

The MWRA already runs a $210 million no-interest, 10-year loan repayment program for member communities to upgrade local water systems, primarily water mains. The new program will be dedicated solely to replacing lead service lines.

Said MWRA Executive Director Fred Laskey: “This will allow those communities that are successful in getting homeowners to participate to move quickly in replacing those lines.”

Matt Rocheleau can be reached at matthew.rocheleau @globe.com. Follow him on Twitter @mrochele.