Malden, Massachusetts
Malden Water Quality
MWRA reservoir water through a system that has served Malden since the late 1800s. Fall 2025 lead hit 17.9 ppb at the 90th percentile — over the action level — while the City replaced more than 330 lead services that year.
Fall 2025 lead 17.9 ppb — and more than 330 lead services replaced the same year.
The short answer
Malden drinks MWRA water from the Quabbin and Wachusett Reservoirs, disinfected with chloramine. Its fall 2025 lead result was 17.9 ppb at the 90th percentile — above the 15 ppb action level — after a spring round that had stayed under at 8.4 ppb.
The same year the City replaced more than 330 lead service lines toward a stated goal of a lead-free city by 2032. Check your address on the City inventory first; a tap test then shows what in-house plumbing still contributes.
Get a free test
Tell us your Malden address. We confirm coverage first, then schedule a licensed technician to test at your tap — no charge, no obligation.
What filtration does — and does not
Softening, carbon and reverse osmosis solve different problems. A filter is not a substitute for replacing a lead service line.
Where Malden water comes from
The same reservoirs as Boston, through Malden's own pipes.
Quabbin and Wachusett Reservoirs
Malden buys treated water from the MWRA, whose sources are the Quabbin and Wachusett Reservoirs in central and western Massachusetts.
Treated at the Carroll plant
MWRA's John J. Carroll Water Treatment Plant in Marlborough disinfects with ozone and UV, adds fluoride, adjusts pH and alkalinity to reduce lead corrosion, and finishes with monochloramine.
Then Malden's distribution
The City's Engineering and Water Departments maintain a system that has served Malden since the late 1800s and deliver MWRA water to homes and businesses.
What the 2025 Malden report actually says
Limits are fixed. Results are from MWRA's 2025 Drinking Water Test Results for Malden, including the City letter — system-level figures, not a reading at your tap. A later report supersedes them.
Fall 2025 lead — 17.9 ppb
The fall round's 90th percentile was 17.9 ppb (range 0.075–24.4), above the 15 ppb action level, with three of twenty homes over the limit. MassDEP was notified within 24 hours.
Spring 2025 was under the action level
The spring round came in at 8.4 ppb at the 90th percentile (range 0.08–22.3), with one of twenty homes over the action level. Malden will sample twice again in 2026.
330+ lead services replaced in 2025
The City's program commits to at least 150 lead water services per year with a goal of a lead-free city by 2032. In 2025 Engineering and Water Utilities replaced more than 330 lead service lines.
Copper stayed under the action level
Spring copper 90th percentile 78.4 ppb; fall 119 ppb — both against a 1,300 ppb action level, with zero samples over the limit in either round.
Free replacement funding in 2026
Two EPA grants, including a congressional directed spending grant facilitated by Rep. Katherine Clark, plus an MWRA grant and zero-interest loan, will fund free lead-line replacement in areas with the most children and underserved populations.
Monochloramine from MWRA
MWRA finishes with chloramine. That shapes filter choice independently of Malden's lead results.
Malden next to Medford, Somerville and Lynn
Across the line, Medford also exceeded the lead action level in 2025 (15.5 ppb) and is under a MassDEP consent order. Somerville reported 3.92 ppb with a replacement program nearly finished. Lynn has its own MWRA water page on this site. Same regional supply; different local pipe stories.
Where these figures come from
Everything on this page traces to MWRA and the City of Malden.
- MWRA — 2025 Drinking Water Test Results, with the City of Malden letter (PDF) — MWRA sources and treatment; Malden's spring and fall lead and copper results, replacement totals and 2026 funding description.
- City of Malden — Drinking Water Notice — the public notice on the action-level exceedance (distributed October 7, 2025).
- City of Malden — Find out if you have lead service lines — inventory lookup and replacement information.
Matching treatment to the finding
Malden's report supports checking your service line and a chloramine-aware filter choice — not a default equipment sale.
Look up your address first
Malden completed a full service-line inventory in October 2024 and posts a Find-out-if-You-Have-Lead-Service-Lines page. If yours shows lead, galvanized or unknown, the City's free or financed replacement programs come first.
Free test and inspection on request
The City's drinking-water notice and letter offer free water testing and service-line inspection on request for older homes — call before buying a filter you may not need.
Certified lead filter as a stopgap
Until a lead service is replaced, a filter certified to reduce lead at the kitchen tap is the practical stopgap — not a substitute for the pipe.
Chloramine taste: catalytic carbon or RO
Ordinary carbon handles free chlorine better than chloramine. If taste or odour is the complaint, catalytic carbon or reverse osmosis is the right tool.
How the free test works
A licensed technician tests at your kitchen tap, walks the plumbing, and tells you which of the findings above applies to your house and which does not. There is no charge and no obligation.
Seamless Home is the licensed contractor of record on the work that follows. Installation is performed by vetted installing partners engaged as our subcontractors, and the workmanship obligation stays with us. Coverage is confirmed per service area rather than promised as blanket availability.
What a water treatment job with us covers
Installation and replacement of whole-home and point-of-use treatment, specified against what your water actually contains.
Sediment filtration
Installation of the first stage that protects everything downstream of it, sized to the service line and the household draw.
Softening
Installation of ion-exchange softening where hardness is the problem, including the drain connection the plumbing code treats as indirect waste.
Carbon filtration
Installation of carbon stages for taste, odour and disinfection by-products, specified from your utility's own water quality report.
Reverse osmosis
Point-of-use installation at the kitchen sink where the target is dissolved solids rather than whole-home flow.
Disinfection
Installation of UV or equivalent treatment where the supply is a private well or is otherwise not continuously disinfected.
System replacement
Replacing equipment that has reached the end of its service life, including the discharge and air gap details an inspector looks at.
This is installation and replacement work, specified from a published water quality report or a test of your supply — not from a sales chart. Coverage is confirmed per service area rather than promised as blanket availability.
What the work actually looks like
Treatment equipment is plumbing. Most of the job is the connection, the drain and the code detail behind it.
Malden water, answered plainly
Where does Malden's water come from?+
From the MWRA. Malden buys treated water from the Quabbin and Wachusett Reservoirs, treated at the John J. Carroll Water Treatment Plant in Marlborough and delivered through the City's own distribution system.
Did Malden exceed the lead action level in 2025?+
Yes, in the fall round. The City's letter shows a fall 2025 90th percentile of 17.9 ppb against a 15 ppb action level (three of twenty homes over). The spring round was 8.4 ppb. Copper stayed under its action level in both rounds.
Is Malden replacing lead service lines?+
Yes. The program commits to at least 150 replacements a year with a goal of a lead-free city by 2032. In 2025 the City replaced more than 330 lead service lines, and 2026 funding includes EPA grants and an MWRA grant/loan for free replacement in priority areas.
How do I check my service line?+
Use the City of Malden's Find-out-if-You-Have-Lead-Service-Lines page (cityofmalden.org), or contact Water Utilities. The City mailed notices in late 2024 to properties with lead, galvanized-requiring-replacement, or unknown service lines on file.
Does Malden use chlorine or chloramine?+
Chloramine. MWRA disinfects with monochloramine before the water reaches Malden's system.
Where do these figures come from?+
MWRA's 2025 Drinking Water Test Results for Malden, which includes the City of Malden Department of Engineering letter (PWS 3165000), and the City's drinking-water notice distributed October 7, 2025. Third-party aggregators are not used. A later report supersedes these figures.
Related resources
Home water purification and treatment
The national service page behind this one.
Learn more →Medford water quality
Next door: 15.5 ppb lead exceedance and a MassDEP ACO.
Learn more →Somerville water quality
MWRA water with a lead replacement program near done.
Learn more →Lynn water quality
Another North Shore MWRA community on this site.
Learn more →Home battery backup in Lynn, MA
National Grid ConnectedSolutions+ incentives for select Lynn circuits.
Learn more →All home services
Water, battery, HVAC and solar under one licensed contractor of record.
Learn more →Get a free test at your tap
A licensed technician tests at your kitchen tap and tells you which findings apply to your house — lead from older plumbing, chloramine taste or none of them. No charge, no obligation, and coverage confirmed at your address first.
Get a free test