Lead water pipes in Boston: how to check yours and get it replaced free

What a lead service line is, and who owns it

The water service is the pipe that runs from the water main under the street into your building. In Boston it has two owners: BWSC owns the public part, and the property owner is responsible for the private part, which BWSC describes as running "from the property line into the building". In older houses that pipe can be lead; BWSC's own guidance says pre-1950 exterior connections may contain lead, and 46.7% of Boston's homes were built in 1939 or earlier, according to the Census Bureau's latest five-year estimates.

Lead doesn't come from the reservoirs. The MWRA, which supplies Boston, treats water at its Carroll plant in Marlborough and adjusts its pH and alkalinity specifically to reduce corrosion of lead from home plumbing, a step it says has cut lead in tap-water tests by nearly 90% since 1996. But where a lead pipe remains, water that sits in it can still pick lead up.

What the latest Boston testing found

Water systems test homes known to have lead service lines, which is why their results run higher than the average tap. In BWSC's fall 2025 sampling, the 90th-percentile result for those homes was 22.5 parts per billion, above the 15 ppb action level, with 4 of 33 samples over the limit. Across all MWRA communities the same round came in at 5.96 ppb, with 18 of 594 homes over. Copper, by contrast, was well within limits in Boston.

An action level isn't a safety threshold; it's the point at which a utility must step up treatment, public education and pipe replacement. For a household, the practical message is simple: if your home has a lead service, get it replaced, and in the meantime use the precautions further down this page.

How to find out whether your home has a lead service

Start with BWSC's records. The commission publishes a water service map where you can look up what it knows about the material of the service at your address, and it mailed letters in 2025 to 7,904 owners and occupants of properties it believed had lead. If the records say unknown, BWSC may be able to inspect visually, and the EPA's advice, as BWSC relays it, is that the best way to be sure is to have a licensed plumber inspect the line.

A plumber looks at the pipe where it comes through the basement wall, before the water meter, and can usually tell lead from copper or galvanized steel in a few minutes. If you're paying for a visit anyway, for a water heater or a leak, ask them to check it while they're there.

• BWSC water service map: bwsc.org water service map
• BWSC Lead Hotline: 617-989-7888
• Outside Boston, your town's water department keeps its own service line inventory; our area pages list each one.

BWSC's no-cost private lead replacement

BWSC's program used to offer owners a credit toward replacing the private side. It now covers the replacement entirely: in the commission's words, "the lead replacement will come at no cost to the owner." BWSC does the work itself, generally between April and October, subject to availability, and nearly 400 privately owned lead services were replaced free of charge in 2025. Its 2025 water report counts about 1,001 inspections and about 448 public and private lead services replaced that year, and sets a goal of removing every lead service by the end of 2032, five years ahead of the federal deadline.

To qualify, all of the following have to be true. If your property doesn't qualify, for example because of a larger service or an obstacle, a licensed plumber can replace the private side with a permit, and should coordinate with BWSC on the public side.

• The property is served by a water service 2 inches or smaller that contains lead.
• The water and sewer account is active and not delinquent.
• The owner agrees to have BWSC do the work.
• There are no extraordinary physical obstacles over the pipe, such as a porch, stairs, a wall, a fence or shrubs.
• BWSC reserves the right to decide eligibility. Call the Lead Hotline, 617-989-7888, to start.

Hiring a plumber to replace it instead

If BWSC's program can't take your property, because of a larger service or an obstacle over the pipe, or you need the work done outside its April-to-October season, a licensed plumber can replace the private side. In Boston that is permit work: plumbing permits are issued only to licensed contractors through the city's Inspectional Services Department, cost $20 plus $5 per fixture, and the contractor has to be on site for the inspection. Ask the plumber to coordinate with BWSC so the public side is dealt with too; replacing only your half leaves the rest of the lead pipe in the ground.

Get the price in writing and ask what it includes. Digging a trench across a front yard, walkway or driveway is the expensive part, and putting the surface back is often priced separately. Keep the permit, the invoice and any photos of the new pipe: a documented lead-free service is useful to have when you refinance or sell, and BWSC can update its records.

Lead pipe programs in the towns around Boston

Every water system in Massachusetts has had to inventory its service lines, and several towns around Boston run their own replacement programs. The details below are from each town's published information; programs change, so check with the town before you plan around them.

• [Cambridge](/areas/cambridge/): about 80% of lead services removed since 1996; the city pays for the public side, and when both sides are done together most of the owner's cost is typically covered.
• [Somerville](/areas/somerville/): a free lead service replacement program ran from 2019 and concluded in 2025.
• [Quincy](/areas/quincy/): completed its inventory in October 2024, replaced 73 lead services in 2024 and aims to remove the rest within ten years.
• [Medford](/areas/medford/): must remove all lead services by 2032; it replaces the public side and offers a $1,000 rebate on the private side.
• [Arlington](/areas/arlington/), [Milton](/areas/milton/) and [Brookline](/areas/brookline/): replace the homeowner's portion of a lead service at no cost.

Reducing lead exposure until the pipe is replaced

BWSC's guidance for homes that may have lead is practical and cheap. None of it replaces getting the pipe out, but together these habits cut exposure considerably, especially for children and anyone pregnant.

• Flush before you drink. If the water has sat unused for more than six hours, run the cold tap until it is noticeably colder; with a lead service, that may take about a minute. In high-rise buildings flushing helps less, so ask the building manager.
• Use only cold water for drinking, cooking and baby formula. Hot water dissolves more lead, faster. Heat cold water on the stove instead.
• Don't rely on boiling. Boiling water does not reduce lead.
• Consider a filter. Reverse osmosis systems and distillers can remove lead; some activated carbon filters reduce it. Check the device's certified performance for lead before buying.
• Test. The only way to know the lead level at your tap is a test by a state-certified laboratory, which typically costs $15 to $50. For children, a blood lead test from the pediatrician is the only way to know about exposure.