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Community Water System · PWS MA4020004

Hyannis Water System, Town of Barnstable

Hyannis, Massachusetts 02601 - drinking water served from groundwater sources to 35,000 people, tracked in EPA SDWIS and UCMR5.

35,000
People served
87
EPA violations
9
Health-based
3 PFAS
UCMR5 result

The verdict

EPA records 87 drinking-water violations at Hyannis Water System, Town of Barnstable, 10% of them health-based - above the Massachusetts per-system average, and UCMR5 testing detected 3 PFAS compounds.

87
Total EPA violations on record
10%
Health-based (MCL / treatment failure)
35,000
People served by this system
3
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Hyannis Water System, Town of Barnstable

Hyannis Water System, Town of Barnstable is a local-owned community water system that delivers drinking water to 35,000 residents in Hyannis, Massachusetts (Barnstable County) through 7,577 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 87 total violations for this system , of which 9 (10%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 64 monitoring and reporting violations are on file. The most recent violation on record dates to 2017.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 11 violations (MR). Under EPA's UCMR5 PFAS monitoring program, 3 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 29.8 ppt (parts per trillion). PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across Massachusetts, EPA tracks 1,599 public water systems serving 10,332,845 people, with 73,886 cumulative violations and 7,389 health-based violations on record. About 95% of systems in the state carry at least one violation, and state-wide the average per system is 46.2 violations. Statewide, 148 of 263 UCMR5-tested systems have reported PFAS detections (56.3%).

Hyannis Water System, Town of Barnstable's 87 violations sit above the Massachusetts average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

3 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
35,000
Total Violations
87
Health-Based Violations
9
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
7,577
County
Barnstable
School/Daycare
No
MCL Violations
9
Monitoring Violations
64
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 11 2009
Coliform (TCR) MCL 9 2009
Lead and Copper Rule MR 4 2009
Nitrate MR 3 2009
Total Haloacetic Acids (HAA5) MR 2 2009
Benzene MR 2 2009
CHLOROBENZENE MR 2 2009
o-Dichlorobenzene MR 2 2009
trans-1,2-Dichloroethylene MR 2 2009
cis-1,2-Dichloroethylene MR 2 2009
1,2-Dichloropropane MR 2 2009
Styrene MR 2 2009
Tetrachloroethylene MR 2 2009
Public Notice Other 2 2007
p-Dichlorobenzene MR 2 2009
DICHLOROMETHANE MR 2 2009
1,1,2-Trichloroethane MR 2 2009
Coliform (TCR) Other 2 2009
Groundwater Rule Other 2 2017
TTHM MR 2 2009
1,2,4-Trichlorobenzene MR 2 2009
1,1,1-Trichloroethane MR 2 2009
Ethylbenzene MR 2 2009
1,1-Dichloroethylene MR 2 2009
1,2-Dichloroethane MR 2 2009
Vinyl chloride MR 2 2009
Trichloroethylene MR 2 2009
Carbon tetrachloride MR 2 2009
Xylenes, Total MR 2 2009
Toluene MR 2 2009

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 9 of 174 samples detected PFAS.

Contaminant Date Result MRL Status
PFDA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFBS 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxS 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFOS 5/16/2023 <4.00 ppt 4.00 ppt Not Detected
PFOA 5/16/2023 <4.00 ppt 4.00 ppt Not Detected
PFHpS 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
NMeFOSAA 5/16/2023 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 5/16/2023 <5.00 ppt 5.00 ppt Not Detected
PFNA 5/16/2023 <4.00 ppt 4.00 ppt Not Detected
PFTA 5/16/2023 <8.00 ppt 8.00 ppt Not Detected
PFDoA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeS 5/16/2023 <4.00 ppt 4.00 ppt Not Detected
NFDHA 5/16/2023 <20.00 ppt 20.00 ppt Not Detected
PFEESA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFMBA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFMPA 5/16/2023 <4.00 ppt 4.00 ppt Not Detected
PFUnA 5/16/2023 <2.00 ppt 2.00 ppt Not Detected
4:2 FTS 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
6:2 FTS 5/16/2023 <5.00 ppt 5.00 ppt Not Detected
PFBA 5/16/2023 <5.00 ppt 5.00 ppt Not Detected
HFPO-DA 5/16/2023 <5.00 ppt 5.00 ppt Not Detected
ADONA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 5/16/2023 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 5/16/2023 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 5/16/2023 <7.00 ppt 7.00 ppt Not Detected
8:2 FTS 5/16/2023 <5.00 ppt 5.00 ppt Not Detected
PFHxA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFEESA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
NEtFOSAA 5/16/2023 <5.00 ppt 5.00 ppt Not Detected
PFHpA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
NFDHA 5/16/2023 <20.00 ppt 20.00 ppt Not Detected
PFPeS 5/16/2023 <4.00 ppt 4.00 ppt Not Detected
PFHpS 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFBS 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxS 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFNA 5/16/2023 <4.00 ppt 4.00 ppt Not Detected
PFMBA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFTrDA 5/16/2023 <7.00 ppt 7.00 ppt Not Detected
4:2 FTS 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
PFTA 5/16/2023 <8.00 ppt 8.00 ppt Not Detected
PFDoA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
ADONA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 5/16/2023 <2.00 ppt 2.00 ppt Not Detected
HFPO-DA 5/16/2023 <5.00 ppt 5.00 ppt Not Detected
PFOS 5/16/2023 <4.00 ppt 4.00 ppt Not Detected
PFOA 5/16/2023 <4.00 ppt 4.00 ppt Not Detected
PFMPA 5/16/2023 <4.00 ppt 4.00 ppt Not Detected
PFDA 5/16/2023 <3.00 ppt 3.00 ppt Not Detected

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Hyannis Water System, Town of Barnstable.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID MA4020004 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Massachusetts Drinking Water Authority

MassDEP, Drinking Water Program is the primacy agency that licenses and inspects Hyannis Water System, Town of Barnstable under EPA-delegated authority.

Open MA regulator portal

Source: MassDEP, Drinking Water Program

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2017 Groundwater Rule Other 2 SDWIS / MA4020004 / 0700
2009 Coliform (TCR) MR 11 SDWIS / MA4020004 / 3100
2009 Coliform (TCR) MCL 9 SDWIS / MA4020004 / 3100
2009 Lead and Copper Rule MR 4 SDWIS / MA4020004 / 5000
2009 Nitrate MR 3 SDWIS / MA4020004 / 1040
2009 Total Haloacetic Acids (HAA5) MR 2 SDWIS / MA4020004 / 2456
2009 Benzene MR 2 SDWIS / MA4020004 / 2990
2009 CHLOROBENZENE MR 2 SDWIS / MA4020004 / 2989
2009 o-Dichlorobenzene MR 2 SDWIS / MA4020004 / 2968
2009 trans-1,2-Dichloroethylene MR 2 SDWIS / MA4020004 / 2979
2009 cis-1,2-Dichloroethylene MR 2 SDWIS / MA4020004 / 2380
2009 1,2-Dichloropropane MR 2 SDWIS / MA4020004 / 2983
2009 Styrene MR 2 SDWIS / MA4020004 / 2996
2009 Tetrachloroethylene MR 2 SDWIS / MA4020004 / 2987
2009 p-Dichlorobenzene MR 2 SDWIS / MA4020004 / 2969

How Hyannis Water System, Town of Barnstable Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Hyannis Water System, Town of Barnstable Massachusetts avg Federal benchmark
Total violations 87 46.2 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 9 4.6 Indicates a contaminant exceeded a federal MCL
PFAS detection 3 compounds 56.3% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 35,000 6,462 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 1,599 regulated public water systems in Massachusetts.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Hyannis Water System, Town of Barnstable water safe to drink? ▼
Hyannis Water System, Town of Barnstable (PWS ID: MA4020004) has 87 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 3 PFAS compounds found. This system serves 35,000 people using Groundwater sources.
How many people does Hyannis Water System, Town of Barnstable serve? ▼
Hyannis Water System, Town of Barnstable serves 35,000 people in Hyannis, Massachusetts. It is a Local-owned system using Groundwater water sources with 7,577 service connections.
What type of violations does Hyannis Water System, Town of Barnstable have? ▼
Hyannis Water System, Town of Barnstable has 87 total violations: 9 health-based violations (MCL exceedances or treatment failures), 64 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Hyannis Water System, Town of Barnstable water? ▼
Yes. UCMR5 testing detected 3 PFAS compounds in Hyannis Water System, Town of Barnstable's water supply: PFPeA, PFBA, PFHxA. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does Hyannis Water System, Town of Barnstable use? ▼
Hyannis Water System, Town of Barnstable uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.