Is Chelmsford, MA tap water safe?

Data: U.S. EPA · How we read the data · How we check it

Chelmsford Water District, the largest system here, had PFAS above the 2024 federal limits (PFOA, PFOS) in EPA's 2023–2025 testing.

Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility issues a boil-water or do-not-drink notice, follow it.

3 public water systems serve parts of Chelmsford. The largest, Chelmsford Water District, serves 28,750 people, and one system here had PFAS above a federal limit. Your water bill names your system.

Largest system

Chelmsford Water District

28,750 people · Groundwater · EPA ID MA3056000

PFAS	Highest average	Limit	Status
PFOA Above limit	7.5 ppt	4 ppt	Above limit
PFOS Above limit	5.65 ppt	4 ppt	Above limit
PFHxS Not detected	–	10 ppt	Not detected
PFNA Not detected	–	10 ppt	Not detected
HFPO-DA (GenX) Not detected	–	10 ppt	Not detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

For context: the PFOA average is higher than at 93% of the Massachusetts systems EPA tested and the PFOS average is higher than at 88% of the Massachusetts systems EPA tested.

Lead: 2.4 ppb at the 90th percentile (Dec 2025, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 1

Full Chelmsford Water District results

Across Massachusetts, 75 of 261 water systems EPA tested had PFAS above a 2024 federal limit, and 8 systems were above the lead action level in results from the last five years. Massachusetts results.

Chelmsford homes and lead pipes

68%

of homes built before 1980 (Massachusetts 67%, US 50%)

18%

built before 1950 (Massachusetts 36%)

18%

of households rent (Massachusetts 38%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Chelmsford town (tables B25034, B25003). Estimates for small places have a margin of error.

Which system serves your ZIP code

Based on the ZIP codes each system reported serving. Boundaries don't follow ZIP lines exactly, so your water bill is the final word.

System	ZIP codes in Chelmsford
Chelmsford Water District 28,750 people	01824
North Chelmsford Water District 7,660 people	01863

Other water systems serving Chelmsford

North Chelmsford Water District
7,660 people · Groundwater · Massachusetts · lists this city
Lithium above screening level
East Chelmsford Water District
2,800 people · Purchased surface water · Massachusetts · lists this city
Not in EPA's PFAS sample

How nearby cities compare

City	Main water system	PFAS	Lead (90th pct.)
Lowell 4 mi Lowell Regional Water Utility	Lowell Regional Water Utility	None above limits	0 ppb
Billerica 6 mi Billerica Water Works	Billerica Water Works	None above limits	2.4 ppb
Dracut 7 mi Dracut Water Supply District	Dracut Water Supply District	Above limit	0 ppb
Tewksbury 7 mi Tewksbury Water Department	Tewksbury Water Department	None above limits	1 ppb
Andover 11 mi Andover Water Dept	Andover Water Dept	None above limits	0 ppb
Lawrence 13 mi Lawrence Water Works	Lawrence Water Works	None above limits	0 ppb

Questions

Is Chelmsford tap water safe to drink?

Chelmsford Water District had 1 health-based violation since 2016, and EPA testing found PFAS above the 2024 federal limits, which it must meet by 2029. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Chelmsford, MA?

3 public water systems serve parts of Chelmsford. The largest is Chelmsford Water District (28,750 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Chelmsford tap water have PFAS?

Yes. EPA's 2023–2025 testing found entry-point averages above the 2024 federal limits for PFOA and PFOS at Chelmsford Water District. Systems have until 2029 to meet them.

Do Chelmsford homes have lead pipes?

Census estimates put 68% of Chelmsford homes as built before 1980 (Massachusetts: 67%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Chelmsford Water District's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.