Is Barnstable Town, MA tap water safe?

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

Centerville Osterville Marstons Mills Water District, the largest system here, had PFAS above the 2024 federal limits (PFOA) 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.

4 public water systems serve parts of Barnstable Town. The largest, Centerville Osterville Marstons Mills Water District, serves 50,000 people, and 2 systems here had PFAS above a federal limit. Your water bill names your system.

Largest system

Centerville Osterville Marstons Mills Water District

50,000 people · Groundwater · EPA ID MA4020002

PFAS	Highest average	Limit	Status
PFOA Above limit	4.85 ppt	4 ppt	Above limit
PFOS Not detected	–	4 ppt	Not detected
PFHxS Detected, below limit	1.55 ppt	10 ppt	Detected, below limit
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 77% of the Massachusetts systems EPA tested.

Lead: 1.82 ppb at the 90th percentile (Jun 2026, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0

Full Centerville Osterville Marstons Mills 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.

Barnstable Town homes and lead pipes

55%

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

13%

built before 1950 (Massachusetts 36%)

24%

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 Barnstable Town city (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 Barnstable Town
Centerville Osterville Marstons Mills Water District 50,000 people	02632, 02647, 02648, 02655, 02672
Barnstable Fire District 5,400 people	02630, 02637, 02668
Hyannis Water System, Town of Barnstable 35,000 people	02601
Cotuit Fire District Water Department 4,938 people	02635

Other water systems serving Barnstable Town

Hyannis Water System, Town of Barnstable
35,000 people · Groundwater · Massachusetts · lists this city
No PFAS above limits
Barnstable Fire District
5,400 people · Groundwater · Massachusetts · lists this city
PFOS above limitAlso: PFOA detected · PFHxS detected
Cotuit Fire District Water Department
4,938 people · Groundwater · Massachusetts · lists this city
No PFAS above limits

How nearby cities compare

City	Main water system	PFAS	Lead (90th pct.)
Yarmouth 7 mi Yarmouth Water Department	Yarmouth Water Department	None above limits	1.5 ppb
Falmouth 13 mi Falmouth Water Dept	Falmouth Water Dept	None above limits	1.1 ppb
Plymouth 21 mi Plymouth Water Department	Plymouth Water Department	None above limits	2.5 ppb
New Bedford 30 mi City of New Bedford Dept. of Public Infrastructure	City of New Bedford Dept. of Public Infrastructure	None above limits	4.1 ppb
Middleborough 30 mi Middleborough Water Supply	Middleborough Water Supply	Above limit	3 ppb
Dartmouth 32 mi Dartmouth Water Division	Dartmouth Water Division	Above limit	7 ppb

Questions

Is Barnstable Town tap water safe to drink?

Centerville Osterville Marstons Mills Water District has had no health-based violations 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 Barnstable Town, MA?

4 public water systems serve parts of Barnstable Town. The largest is Centerville Osterville Marstons Mills Water District (50,000 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Barnstable Town tap water have PFAS?

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

Do Barnstable Town homes have lead pipes?

Census estimates put 55% of Barnstable Town 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. Centerville Osterville Marstons Mills 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.