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Community Water System · PWS MA2270001

McI Shirley

Milford, Massachusetts 01757 - drinking water served from groundwater sources to 3,500 people, tracked in EPA SDWIS and UCMR5.

3,500
People served
172
EPA violations
16
Health-based
1 PFAS
UCMR5 result

The verdict

EPA records 172 drinking-water violations at McI Shirley, 9% of them health-based - above the Massachusetts per-system average, and UCMR5 testing detected 1 PFAS compound.

172
Total EPA violations on record
9%
Health-based (MCL / treatment failure)
3,500
People served by this system
1
PFAS compounds detected (UCMR5)

Water Quality Snapshot: McI Shirley

McI Shirley is a state-owned community water system that delivers drinking water to 3,500 residents in Milford, Massachusetts (Middlesex County) through 3 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 172 total violations for this system , of which 16 (9%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 136 monitoring and reporting violations are on file. The most recent violation on record dates to 2008.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 15 violations (MR). Under EPA's UCMR5 PFAS monitoring program, 1 PFAS compound was detected in samples collected from this system, with a maximum reported concentration of 8.7 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%).

McI Shirley's 172 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

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

Population Served
3,500
Total Violations
172
Health-Based Violations
16
Water Source
Groundwater

System Details

System Type
Community
Owner Type
State
Connections
3
County
Middlesex
School/Daycare
No
MCL Violations
9
Monitoring Violations
136
Treatment Tech Violations
7

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 15 2004
Coliform (TCR) MCL 8 2007
Lead and Copper Rule TT 7 2003
Arsenic MR 5 2003
1,2,4-Trichlorobenzene MR 5 2008
Xylenes, Total MR 5 2008
DICHLOROMETHANE MR 5 2008
p-Dichlorobenzene MR 5 2008
trans-1,2-Dichloroethylene MR 5 2008
1,2-Dichloroethane MR 5 2008
1,1,1-Trichloroethane MR 5 2008
Carbon tetrachloride MR 5 2008
CHLOROBENZENE MR 5 2008
Styrene MR 5 2008
o-Dichlorobenzene MR 5 2008
cis-1,2-Dichloroethylene MR 5 2008
1,2-Dichloropropane MR 5 2008
Tetrachloroethylene MR 5 2008
Toluene MR 5 2008
1,1,2-Trichloroethane MR 5 2008
Vinyl chloride MR 5 2008
1,1-Dichloroethylene MR 5 2008
Trichloroethylene MR 5 2008
Benzene MR 5 2008
Ethylbenzene MR 5 2008
Consumer Confidence Rule Other 4 2006
Nitrate MR 3 2008
Lead and Copper Rule MR 2 2002
Arsenic MCL 1 2006
Endrin MR 1 1991

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 2 of 58 samples detected PFAS.

Contaminant Date Result MRL Status
9Cl-PF3ONS 8/21/2023 <2.00 ppt 2.00 ppt Not Detected
PFBA 8/21/2023 <5.00 ppt 5.00 ppt Not Detected
HFPO-DA 8/21/2023 <5.00 ppt 5.00 ppt Not Detected
PFHpS 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeS 8/21/2023 <4.00 ppt 4.00 ppt Not Detected
NFDHA 8/21/2023 <20.00 ppt 20.00 ppt Not Detected
PFEESA 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFMBA 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeA 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFMPA 8/21/2023 <4.00 ppt 4.00 ppt Not Detected
8:2 FTS 8/21/2023 <5.00 ppt 5.00 ppt Not Detected
6:2 FTS 8/21/2023 <5.00 ppt 5.00 ppt Not Detected
PFDA 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFBS 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxS 8/21/2023 8.70 ppt 3.00 ppt Detected
PFNA 8/21/2023 <4.00 ppt 4.00 ppt Not Detected
4:2 FTS 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFOA 8/21/2023 <4.00 ppt 4.00 ppt Not Detected
PFDoA 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxA 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFUnA 8/21/2023 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 8/21/2023 <5.00 ppt 5.00 ppt Not Detected
ADONA 8/21/2023 <3.00 ppt 3.00 ppt Not Detected
PFOS 8/21/2023 <4.00 ppt 4.00 ppt Not Detected
NEtFOSAA 12/11/2023 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 12/11/2023 <7.00 ppt 7.00 ppt Not Detected
PFTA 12/11/2023 <8.00 ppt 8.00 ppt Not Detected
NMeFOSAA 12/11/2023 <6.00 ppt 6.00 ppt Not Detected
NFDHA 10/31/2023 <20.00 ppt 20.00 ppt Not Detected
9Cl-PF3ONS 10/31/2023 <2.00 ppt 2.00 ppt Not Detected
NEtFOSAA 10/31/2023 <5.00 ppt 5.00 ppt Not Detected
PFTA 10/31/2023 <8.00 ppt 8.00 ppt Not Detected
PFEESA 10/31/2023 <3.00 ppt 3.00 ppt Not Detected
PFMBA 10/31/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeA 10/31/2023 <3.00 ppt 3.00 ppt Not Detected
PFMPA 10/31/2023 <4.00 ppt 4.00 ppt Not Detected
8:2 FTS 10/31/2023 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 10/31/2023 <3.00 ppt 3.00 ppt Not Detected
6:2 FTS 10/31/2023 <5.00 ppt 5.00 ppt Not Detected
PFBA 10/31/2023 <5.00 ppt 5.00 ppt Not Detected
PFBS 10/31/2023 <3.00 ppt 3.00 ppt Not Detected
ADONA 10/31/2023 <3.00 ppt 3.00 ppt Not Detected
PFOA 10/31/2023 <4.00 ppt 4.00 ppt Not Detected
PFTrDA 10/31/2023 <7.00 ppt 7.00 ppt Not Detected
PFPeS 10/31/2023 <4.00 ppt 4.00 ppt Not Detected
PFHpS 10/31/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 10/31/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxS 10/31/2023 8.60 ppt 3.00 ppt Detected
HFPO-DA 10/31/2023 <5.00 ppt 5.00 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 McI Shirley.

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 MA2270001 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 McI Shirley 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
2008 1,2,4-Trichlorobenzene MR 5 SDWIS / MA2270001 / 2378
2008 Xylenes, Total MR 5 SDWIS / MA2270001 / 2955
2008 DICHLOROMETHANE MR 5 SDWIS / MA2270001 / 2964
2008 p-Dichlorobenzene MR 5 SDWIS / MA2270001 / 2969
2008 trans-1,2-Dichloroethylene MR 5 SDWIS / MA2270001 / 2979
2008 1,2-Dichloroethane MR 5 SDWIS / MA2270001 / 2980
2008 1,1,1-Trichloroethane MR 5 SDWIS / MA2270001 / 2981
2008 Carbon tetrachloride MR 5 SDWIS / MA2270001 / 2982
2008 CHLOROBENZENE MR 5 SDWIS / MA2270001 / 2989
2008 Styrene MR 5 SDWIS / MA2270001 / 2996
2008 o-Dichlorobenzene MR 5 SDWIS / MA2270001 / 2968
2008 cis-1,2-Dichloroethylene MR 5 SDWIS / MA2270001 / 2380
2008 1,2-Dichloropropane MR 5 SDWIS / MA2270001 / 2983
2008 Tetrachloroethylene MR 5 SDWIS / MA2270001 / 2987
2008 Toluene MR 5 SDWIS / MA2270001 / 2991

How McI Shirley Compares

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

Metric McI Shirley Massachusetts avg Federal benchmark
Total violations 172 46.2 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 16 4.6 Indicates a contaminant exceeded a federal MCL
PFAS detection 1 compound 56.3% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 3,500 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 McI Shirley water safe to drink? ▼
McI Shirley (PWS ID: MA2270001) has 172 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 1 PFAS compound found. This system serves 3,500 people using Groundwater sources.
How many people does McI Shirley serve? ▼
McI Shirley serves 3,500 people in Milford, Massachusetts. It is a State-owned system using Groundwater water sources with 3 service connections.
What type of violations does McI Shirley have? ▼
McI Shirley has 172 total violations: 16 health-based violations (MCL exceedances or treatment failures), 136 monitoring/reporting violations, and 7 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in McI Shirley water? ▼
Yes. UCMR5 testing detected 1 PFAS compound in McI Shirley's water supply: PFHxS. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does McI Shirley use? ▼
McI Shirley 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.