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Community Water System · PWS NY5103705

Riverhead Water District

Riverhead, New York 11901 - drinking water served from groundwater sources to 35,000 people, tracked in EPA SDWIS and UCMR5.

35,000
People served
156
EPA violations
3
Health-based
4 PFAS
UCMR5 result

The verdict

EPA records 156 drinking-water violations at Riverhead Water District, 2% of them health-based - above the New York per-system average, and UCMR5 testing detected 4 PFAS compounds.

156
Total EPA violations on record
2%
Health-based (MCL / treatment failure)
35,000
People served by this system
4
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Riverhead Water District

Riverhead Water District is a local-owned community water system that delivers drinking water to 35,000 residents in Riverhead, New York (Suffolk County) through 9,334 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 156 total violations for this system , of which 3 (2%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 147 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 cis-1,2-Dichloroethylene, recorded in 3 violations (MR). Under EPA's UCMR5 PFAS monitoring program, 4 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 5.2 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%).

Riverhead Water District's 156 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

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

Population Served
35,000
Total Violations
156
Health-Based Violations
3
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
9,334
County
Suffolk
School/Daycare
No
MCL Violations
3
Monitoring Violations
147
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
cis-1,2-Dichloroethylene MR 3 2010
o-Dichlorobenzene MR 3 2010
1,1-Dichloroethylene MR 3 2010
1,2-Dichloroethane MR 3 2010
Carbon tetrachloride MR 3 2010
Trichloroethylene MR 3 2010
Tetrachloroethylene MR 3 2010
CHLOROBENZENE MR 3 2010
Benzene MR 3 2010
Toluene MR 3 2010
Ethylbenzene MR 3 2010
Styrene MR 3 2010
BHC-GAMMA MR 3 2010
Toxaphene MR 3 2010
Dalapon MR 3 2010
Di(2-ethylhexyl) adipate MR 3 2010
Di(2-ethylhexyl) phthalate MR 3 2010
Picloram MR 3 2010
Dinoseb MR 3 2010
Hexachlorocyclopentadiene MR 3 2010
Aldicarb sulfoxide MR 3 2010
Aldicarb sulfone MR 3 2010
Atrazine MR 3 2010
LASSO MR 3 2010
Heptachlor MR 3 2010
Benzo(a)pyrene MR 3 2010
Total Polychlorinated Biphenyls (PCB) MR 3 2010
Chlordane MR 3 2010
Consumer Confidence Rule Other 3 2010
Nitrate-Nitrite MR 3 2023

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 4 of 580 samples detected PFAS.

Contaminant Date Result MRL Status
NMeFOSAA 7/6/2023 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 7/6/2023 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 7/6/2023 <7.00 ppt 7.00 ppt Not Detected
PFTA 7/6/2023 <8.00 ppt 8.00 ppt Not Detected
PFTA 7/31/2023 <8.00 ppt 8.00 ppt Not Detected
NMeFOSAA 7/31/2023 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 7/31/2023 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 7/31/2023 <7.00 ppt 7.00 ppt Not Detected
NMeFOSAA 7/17/2023 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 7/17/2023 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 7/17/2023 <7.00 ppt 7.00 ppt Not Detected
PFTA 7/17/2023 <8.00 ppt 8.00 ppt Not Detected
PFNA 6/20/2023 <4.00 ppt 4.00 ppt Not Detected
PFHpS 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeS 6/20/2023 <4.00 ppt 4.00 ppt Not Detected
PFEESA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
NFDHA 6/20/2023 <20.00 ppt 20.00 ppt Not Detected
6:2 FTS 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
PFHxS 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFOS 6/20/2023 <4.00 ppt 4.00 ppt Not Detected
PFTrDA 6/20/2023 <7.00 ppt 7.00 ppt Not Detected
PFBS 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFOA 6/20/2023 <4.00 ppt 4.00 ppt Not Detected
PFMBA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFMPA 6/20/2023 <4.00 ppt 4.00 ppt Not Detected
PFHpA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFUnA 6/20/2023 <2.00 ppt 2.00 ppt Not Detected
PFBA 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
HFPO-DA 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
ADONA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 6/20/2023 <2.00 ppt 2.00 ppt Not Detected
8:2 FTS 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
11Cl-PF3OUdS 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
PFTA 6/20/2023 <8.00 ppt 8.00 ppt Not Detected
PFHxA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFDoA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFDA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
NMeFOSAA 6/20/2023 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
PFDoA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFUnA 6/20/2023 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
9Cl-PF3ONS 6/20/2023 <2.00 ppt 2.00 ppt Not Detected
ADONA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
HFPO-DA 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
PFBA 6/20/2023 <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 Riverhead Water District.

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 NY5103705 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 Riverhead Water District 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
2023 Nitrate-Nitrite MR 3 SDWIS / NY5103705 / 1038
2023 Nitrite MCL 3 SDWIS / NY5103705 / 1041
2010 cis-1,2-Dichloroethylene MR 3 SDWIS / NY5103705 / 2380
2010 o-Dichlorobenzene MR 3 SDWIS / NY5103705 / 2968
2010 1,1-Dichloroethylene MR 3 SDWIS / NY5103705 / 2977
2010 1,2-Dichloroethane MR 3 SDWIS / NY5103705 / 2980
2010 Carbon tetrachloride MR 3 SDWIS / NY5103705 / 2982
2010 Trichloroethylene MR 3 SDWIS / NY5103705 / 2984
2010 Tetrachloroethylene MR 3 SDWIS / NY5103705 / 2987
2010 CHLOROBENZENE MR 3 SDWIS / NY5103705 / 2989
2010 Benzene MR 3 SDWIS / NY5103705 / 2990
2010 Toluene MR 3 SDWIS / NY5103705 / 2991
2010 Ethylbenzene MR 3 SDWIS / NY5103705 / 2992
2010 Styrene MR 3 SDWIS / NY5103705 / 2996
2010 BHC-GAMMA MR 3 SDWIS / NY5103705 / 2010

How Riverhead Water District Compares

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

Metric Riverhead Water District New York avg Federal benchmark
Total violations 156 68.2 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 3 3.3 Indicates a contaminant exceeded a federal MCL
PFAS detection 4 compounds 38.9% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 35,000 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 Riverhead Water District water safe to drink? ▼
Riverhead Water District (PWS ID: NY5103705) has 156 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 4 PFAS compounds found. This system serves 35,000 people using Groundwater sources.
How many people does Riverhead Water District serve? ▼
Riverhead Water District serves 35,000 people in Riverhead, New York. It is a Local-owned system using Groundwater water sources with 9,334 service connections.
What type of violations does Riverhead Water District have? ▼
Riverhead Water District has 156 total violations: 3 health-based violations (MCL exceedances or treatment failures), 147 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Riverhead Water District water? ▼
Yes. UCMR5 testing detected 4 PFAS compounds in Riverhead Water District's water supply: PFHxA, PFOA, PFOS, PFPeA. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does Riverhead Water District use? ▼
Riverhead Water District 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.