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Non-Transient Non-Community Water System · PWS MA4062008

Chilmark School

Chilmark, Massachusetts 02535 - drinking water served from groundwater sources to 90 people, tracked in EPA SDWIS and UCMR5.

90
People served
117
EPA violations
7
Health-based
Untested
UCMR5 result

The verdict

EPA records 117 drinking-water violations at Chilmark School, 6% of them health-based - above the Massachusetts per-system average.

117
Total EPA violations on record
6%
Health-based (MCL / treatment failure)
90
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Chilmark School

Chilmark School is a local-owned non-transient non-community water system that delivers drinking water to 90 residents in Chilmark, Massachusetts (Dukes County) through 0 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 117 total violations for this system , of which 7 (6%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 97 monitoring and reporting violations are on file. The most recent violation on record dates to 2023.

The most frequently cited contaminant at this system is Lead and Copper Rule, recorded in 9 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

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%).

Chilmark School's 117 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.

Population Served
90
Total Violations
117
Health-Based Violations
7
Water Source
Groundwater

System Details

System Type
Non-Transient Non-Community
Owner Type
Local
Connections
0
County
Dukes
School/Daycare
Yes
MCL Violations
4
Monitoring Violations
97
Treatment Tech Violations
3

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Lead and Copper Rule MR 9 2021
Coliform (TCR) MR 4 2010
Coliform (TCR) MCL 4 2010
Revised Total Coliform Rule TT 3 2020
1,1,1-Trichloroethane MR 2 2010
o-Dichlorobenzene MR 2 2010
cis-1,2-Dichloroethylene MR 2 2010
1,2-Dichloropropane MR 2 2010
Ethylbenzene MR 2 2010
Styrene MR 2 2010
p-Dichlorobenzene MR 2 2010
DICHLOROMETHANE MR 2 2010
1,1,2-Trichloroethane MR 2 2010
1,1-Dichloroethylene MR 2 2010
Trichloroethylene MR 2 2010
Carbon tetrachloride MR 2 2010
Vinyl chloride MR 2 2010
Public Notice Other 2 2020
Benzene MR 2 2010
1,2,4-Trichlorobenzene MR 2 2010
Toluene MR 2 2010
CHLOROBENZENE MR 2 2010
trans-1,2-Dichloroethylene MR 2 2010
Tetrachloroethylene MR 2 2010
Xylenes, Total MR 2 2010
1,2-Dichloroethane MR 2 2010
Barium MR 1 2002
Cadmium MR 1 2002
CYANIDE MR 1 2002
Fluoride MR 1 2002

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 Chilmark School.

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 MA4062008 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 Chilmark School 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
2023 Chlordane MR 1 SDWIS / MA4062008 / 2959
2023 2,4-D MR 1 SDWIS / MA4062008 / 2105
2023 Endrin MR 1 SDWIS / MA4062008 / 2005
2023 Heptachlor epoxide MR 1 SDWIS / MA4062008 / 2067
2023 Heptachlor MR 1 SDWIS / MA4062008 / 2065
2023 2,4,5-TP MR 1 SDWIS / MA4062008 / 2110
2023 Methoxychlor MR 1 SDWIS / MA4062008 / 2015
2023 BHC-GAMMA MR 1 SDWIS / MA4062008 / 2010
2023 Total Polychlorinated Biphenyls (PCB) MR 1 SDWIS / MA4062008 / 2383
2023 1,2-DIBROMO-3-CHLOROPROPANE MR 1 SDWIS / MA4062008 / 2931
2023 Dalapon MR 1 SDWIS / MA4062008 / 2031
2023 Di(2-ethylhexyl) adipate MR 1 SDWIS / MA4062008 / 2035
2023 Di(2-ethylhexyl) phthalate MR 1 SDWIS / MA4062008 / 2039
2023 Diquat MR 1 SDWIS / MA4062008 / 2032
2023 Glyphosate MR 1 SDWIS / MA4062008 / 2034

How Chilmark School Compares

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

Metric Chilmark School Massachusetts avg Federal benchmark
Total violations 117 46.2 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 7 4.6 Indicates a contaminant exceeded a federal MCL
PFAS detection None 56.3% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 90 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 Chilmark School water safe to drink? ▼
Chilmark School (PWS ID: MA4062008) has 117 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 90 people using Groundwater sources.
How many people does Chilmark School serve? ▼
Chilmark School serves 90 people in Chilmark, Massachusetts. It is a Local-owned system using Groundwater water sources with 0 service connections.
What type of violations does Chilmark School have? ▼
Chilmark School has 117 total violations: 7 health-based violations (MCL exceedances or treatment failures), 97 monitoring/reporting violations, and 3 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Chilmark School water? ▼
No PFAS testing data is available for Chilmark School under the EPA's UCMR5 monitoring program.
What water source does Chilmark School use? ▼
Chilmark School uses Groundwater as its primary water source. It is classified as a Non-Transient Non-Community Water System, serving the same people for at least 6 months per year.
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. 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.