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Community Water System · PWS NY5903451

Ossining Water Department

Ossining, New York 10562 - drinking water served from surface water sources to 30,000 people, tracked in EPA SDWIS and UCMR5.

30,000
People served
311
EPA violations
12
Health-based
1 PFAS
UCMR5 result

The verdict

EPA records 311 drinking-water violations at Ossining Water Department, 4% of them health-based - above the New York per-system average, and UCMR5 testing detected 1 PFAS compound.

311
Total EPA violations on record
4%
Health-based (MCL / treatment failure)
30,000
People served by this system
1
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Ossining Water Department

Ossining Water Department is a local-owned community water system that delivers drinking water to 30,000 residents in Ossining, New York (Westchester County) through 6,600 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 311 total violations for this system , of which 12 (4%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 288 monitoring and reporting violations are on file. The most recent violation on record dates to 2022.

The most frequently cited contaminant at this system is Interim Enhanced Surface Water Treatment Rule, recorded in 12 violations (TT, health-based). Under EPA's UCMR5 PFAS monitoring program, 1 PFAS compound was detected in samples collected from this system, with a maximum reported concentration of 4.3 ppt (parts per trillion). PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across New York, EPA tracks 8,098 public water systems serving 19,294,951 people, with 552,003 cumulative violations and 26,817 health-based violations on record. About 94% of systems in the state carry at least one violation, and state-wide the average per system is 68.2 violations. Statewide, 129 of 332 UCMR5-tested systems have reported PFAS detections (38.9%).

Ossining Water Department's 311 violations sit above the New York 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
30,000
Total Violations
311
Health-Based Violations
12
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
6,600
County
Westchester
School/Daycare
No
MCL Violations
0
Monitoring Violations
288
Treatment Tech Violations
12

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Interim Enhanced Surface Water Treatment Rule TT 12 2004
1,2,4-Trichlorobenzene MR 7 2015
cis-1,2-Dichloroethylene MR 7 2015
o-Dichlorobenzene MR 7 2015
1,2-Dichloroethane MR 7 2015
Carbon tetrachloride MR 7 2015
Trichloroethylene MR 7 2015
Tetrachloroethylene MR 7 2015
Benzene MR 7 2015
Ethylbenzene MR 7 2015
Styrene MR 7 2015
DICHLOROMETHANE MR 7 2015
p-Dichlorobenzene MR 7 2015
Vinyl chloride MR 7 2015
1,1-Dichloroethylene MR 7 2015
trans-1,2-Dichloroethylene MR 7 2015
1,1,1-Trichloroethane MR 7 2015
CHLOROBENZENE MR 7 2015
Toluene MR 7 2015
1,1,2-Trichloroethane MR 7 2015
1,2-Dichloropropane MR 7 2015
Chromium MR 4 2007
Nickel MR 4 2007
Antimony, Total MR 4 2007
Mercury MR 4 2007
Total Haloacetic Acids (HAA5) MR 4 2022
Coliform (TCR) MR 4 2010
Selenium MR 4 2007
Barium MR 4 2007
Interim Enhanced Surface Water Treatment Rule MR 4 2009

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 1 of 116 samples detected PFAS.

Contaminant Date Result MRL Status
PFMPA 6/12/2023 <4.00 ppt 4.00 ppt Not Detected
PFNA 6/12/2023 <4.00 ppt 4.00 ppt Not Detected
NFDHA 6/12/2023 <20.00 ppt 20.00 ppt Not Detected
PFPeA 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
PFMBA 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
PFEESA 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpS 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
PFTA 6/12/2023 <8.00 ppt 8.00 ppt Not Detected
PFTrDA 6/12/2023 <7.00 ppt 7.00 ppt Not Detected
NMeFOSAA 6/12/2023 <6.00 ppt 6.00 ppt Not Detected
PFHxS 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
PFBA 6/12/2023 <5.00 ppt 5.00 ppt Not Detected
NEtFOSAA 6/12/2023 <5.00 ppt 5.00 ppt Not Detected
PFHxA 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
PFOA 6/12/2023 <4.00 ppt 4.00 ppt Not Detected
PFDA 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 6/12/2023 <5.00 ppt 5.00 ppt Not Detected
PFDoA 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
PFUnA 6/12/2023 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 6/12/2023 <5.00 ppt 5.00 ppt Not Detected
9Cl-PF3ONS 6/12/2023 <2.00 ppt 2.00 ppt Not Detected
PFOS 6/12/2023 <4.00 ppt 4.00 ppt Not Detected
HFPO-DA 6/12/2023 <5.00 ppt 5.00 ppt Not Detected
6:2 FTS 6/12/2023 <5.00 ppt 5.00 ppt Not Detected
PFPeS 6/12/2023 <4.00 ppt 4.00 ppt Not Detected
4:2 FTS 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
PFBS 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
ADONA 6/12/2023 <3.00 ppt 3.00 ppt Not Detected
HFPO-DA 3/7/2023 <5.00 ppt 5.00 ppt Not Detected
PFHpA 3/7/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpS 3/7/2023 <3.00 ppt 3.00 ppt Not Detected
NMeFOSAA 3/7/2023 <6.00 ppt 6.00 ppt Not Detected
9Cl-PF3ONS 3/7/2023 <2.00 ppt 2.00 ppt Not Detected
PFPeS 3/7/2023 <4.00 ppt 4.00 ppt Not Detected
PFEESA 3/7/2023 <3.00 ppt 3.00 ppt Not Detected
PFMBA 3/7/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeA 3/7/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxS 3/7/2023 <3.00 ppt 3.00 ppt Not Detected
PFBS 3/7/2023 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 3/7/2023 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 3/7/2023 <3.00 ppt 3.00 ppt Not Detected
6:2 FTS 3/7/2023 <5.00 ppt 5.00 ppt Not Detected
PFBA 3/7/2023 <5.00 ppt 5.00 ppt Not Detected
PFOS 3/7/2023 <4.00 ppt 4.00 ppt Not Detected
PFTrDA 3/7/2023 <7.00 ppt 7.00 ppt Not Detected
PFMPA 3/7/2023 <4.00 ppt 4.00 ppt Not Detected
PFTA 3/7/2023 <8.00 ppt 8.00 ppt Not Detected
PFUnA 3/7/2023 <2.00 ppt 2.00 ppt Not Detected
PFNA 3/7/2023 <4.00 ppt 4.00 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 Ossining Water Department.

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 NY5903451 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

New York Drinking Water Authority

New York State Department of Health, Public Water Systems is the primacy agency that licenses and inspects Ossining Water Department under EPA-delegated authority.

Open NY regulator portal

Source: New York State Department of Health, Public Water Systems

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
2022 Total Haloacetic Acids (HAA5) MR 4 SDWIS / NY5903451 / 2456
2022 TTHM MR 4 SDWIS / NY5903451 / 2950
2015 1,2,4-Trichlorobenzene MR 7 SDWIS / NY5903451 / 2378
2015 cis-1,2-Dichloroethylene MR 7 SDWIS / NY5903451 / 2380
2015 o-Dichlorobenzene MR 7 SDWIS / NY5903451 / 2968
2015 1,2-Dichloroethane MR 7 SDWIS / NY5903451 / 2980
2015 Carbon tetrachloride MR 7 SDWIS / NY5903451 / 2982
2015 Trichloroethylene MR 7 SDWIS / NY5903451 / 2984
2015 Tetrachloroethylene MR 7 SDWIS / NY5903451 / 2987
2015 Benzene MR 7 SDWIS / NY5903451 / 2990
2015 Ethylbenzene MR 7 SDWIS / NY5903451 / 2992
2015 Styrene MR 7 SDWIS / NY5903451 / 2996
2015 DICHLOROMETHANE MR 7 SDWIS / NY5903451 / 2964
2015 p-Dichlorobenzene MR 7 SDWIS / NY5903451 / 2969
2015 Vinyl chloride MR 7 SDWIS / NY5903451 / 2976

How Ossining Water Department Compares

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

Metric Ossining Water Department New York avg Federal benchmark
Total violations 311 68.2 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 12 3.3 Indicates a contaminant exceeded a federal MCL
PFAS detection 1 compound 38.9% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 30,000 2,383 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 8,098 regulated public water systems in New York.

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 Ossining Water Department water safe to drink? ▼
Ossining Water Department (PWS ID: NY5903451) has 311 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 1 PFAS compound found. This system serves 30,000 people using Surface Water sources.
How many people does Ossining Water Department serve? ▼
Ossining Water Department serves 30,000 people in Ossining, New York. It is a Local-owned system using Surface Water water sources with 6,600 service connections.
What type of violations does Ossining Water Department have? ▼
Ossining Water Department has 311 total violations: 12 health-based violations (MCL exceedances or treatment failures), 288 monitoring/reporting violations, and 12 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Ossining Water Department water? ▼
Yes. UCMR5 testing detected 1 PFAS compound in Ossining Water Department's water supply: PFOA. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does Ossining Water Department use? ▼
Ossining Water Department uses Surface Water 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.