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Transient Non-Community Water System · PWS NY2916010

Seawanhaka Yacht Club

Oyster Bay, New York 11771 - drinking water served from groundwater sources to 60 people, tracked in EPA SDWIS and UCMR5.

60
People served
298
EPA violations
0
Health-based
Untested
UCMR5 result

The verdict

EPA records 298 drinking-water violations at Seawanhaka Yacht Club - above the New York per-system average.

298
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
60
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Seawanhaka Yacht Club

Seawanhaka Yacht Club is a public/private-owned transient non-community water system that delivers drinking water to 60 residents in Oyster Bay, New York (Nassau County) through 1 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 298 total violations for this system , of which 0 (0%) 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 2011.

The most frequently cited contaminant at this system is Endrin, recorded in 4 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 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%).

Seawanhaka Yacht Club's 298 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.

Population Served
60
Total Violations
298
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Transient Non-Community
Owner Type
Public/Private
Connections
1
County
Nassau
School/Daycare
No
MCL Violations
0
Monitoring Violations
136
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Endrin MR 4 2011
BHC-GAMMA MR 4 2011
Dalapon MR 4 2011
Di(2-ethylhexyl) phthalate MR 4 2011
Dinoseb MR 4 2011
Hexachlorocyclopentadiene MR 4 2011
Aldicarb sulfoxide MR 4 2011
Aldicarb sulfone MR 4 2011
Carbofuran MR 4 2011
Heptachlor MR 4 2011
Heptachlor epoxide MR 4 2011
2,4-D MR 4 2011
HEXACHLOROBENZENE MR 4 2011
Pentachlorophenol MR 4 2011
Total Polychlorinated Biphenyls (PCB) MR 4 2011
Chlordane MR 4 2011
Simazine MR 4 2011
ETHYLENE DIBROMIDE MR 4 2011
Aldicarb MR 4 2011
Picloram MR 4 2011
Atrazine MR 4 2011
Benzo(a)pyrene MR 4 2011
Toxaphene MR 4 2011
2,4,5-TP MR 4 2011
LASSO MR 4 2011
Di(2-ethylhexyl) adipate MR 4 2011
Methoxychlor MR 4 2011
OXAMYL MR 4 2011
Arsenic MR 2 1999
Nickel MR 2 1999

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 Seawanhaka Yacht Club.

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 NY2916010 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 Seawanhaka Yacht Club 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
2011 Endrin MR 4 SDWIS / NY2916010 / 2005
2011 BHC-GAMMA MR 4 SDWIS / NY2916010 / 2010
2011 Dalapon MR 4 SDWIS / NY2916010 / 2031
2011 Di(2-ethylhexyl) phthalate MR 4 SDWIS / NY2916010 / 2039
2011 Dinoseb MR 4 SDWIS / NY2916010 / 2041
2011 Hexachlorocyclopentadiene MR 4 SDWIS / NY2916010 / 2042
2011 Aldicarb sulfoxide MR 4 SDWIS / NY2916010 / 2043
2011 Aldicarb sulfone MR 4 SDWIS / NY2916010 / 2044
2011 Carbofuran MR 4 SDWIS / NY2916010 / 2046
2011 Heptachlor MR 4 SDWIS / NY2916010 / 2065
2011 Heptachlor epoxide MR 4 SDWIS / NY2916010 / 2067
2011 2,4-D MR 4 SDWIS / NY2916010 / 2105
2011 HEXACHLOROBENZENE MR 4 SDWIS / NY2916010 / 2274
2011 Pentachlorophenol MR 4 SDWIS / NY2916010 / 2326
2011 Total Polychlorinated Biphenyls (PCB) MR 4 SDWIS / NY2916010 / 2383

How Seawanhaka Yacht Club Compares

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

Metric Seawanhaka Yacht Club New York avg Federal benchmark
Total violations 298 68.2 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 0 3.3 Indicates a contaminant exceeded a federal MCL
PFAS detection None 38.9% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 60 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 Seawanhaka Yacht Club water safe to drink? ▼
Seawanhaka Yacht Club (PWS ID: NY2916010) has 298 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 60 people using Groundwater sources.
How many people does Seawanhaka Yacht Club serve? ▼
Seawanhaka Yacht Club serves 60 people in Oyster Bay, New York. It is a Public/Private-owned system using Groundwater water sources with 1 service connections.
What type of violations does Seawanhaka Yacht Club have? ▼
Seawanhaka Yacht Club has 298 total violations: 0 health-based violations (MCL exceedances or treatment failures), 136 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Seawanhaka Yacht Club water? ▼
No PFAS testing data is available for Seawanhaka Yacht Club under the EPA's UCMR5 monitoring program.
What water source does Seawanhaka Yacht Club use? ▼
Seawanhaka Yacht Club uses Groundwater as its primary water source. It is classified as a Transient Non-Community Water System, serving transient populations.
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.