Public water system · NY5103700
ActiveDering Harbor Water District
At a glance
Dering Harbor Water District (PWSID NY5103700) is an active community water system in Suffolk County, New York. It reports serving 14 people through 37 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2014.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
14
Service connections
37
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Dering Harbor Water District compare with other water systems in Suffolk County?
By EPA's size categories, Dering Harbor Water District is a very small system (500 people or fewer). Suffolk County has 151 active public water systems. Its population served is well below the county average of 9,192 people per system, and accounts for less than 0.1% of the 1,387,972 people reported by systems filed under the county. Across New York, the 8,167 active systems average 2,374 people each. Nationally, the average active community water system reports serving 6,703 people, so Dering Harbor Water District is well below that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. New York has 2,281 active community water systems, 28% of the state's 8,167 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 7,096 New York systems (87%) list groundwater as their primary source.
Who owns and regulates Dering Harbor Water District?
EPA lists Dering Harbor Water District as owned by a local government. The NY state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 38 of the 151 active systems in Suffolk County (25%) are also owned by a local government.
Does Dering Harbor Water District have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2014. The violations listed here began between January 2004 and January 2014. By type: 11 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminants or rules involved are Mercury, Haloacetic acids (HAA5), Consumer Confidence Rule and Picloram. EPA lists 12 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2014-01-01 | Monitoring and reportingMonitoring, Check/Repeat/Confirmation · code 04 | Mercurycode 1035 | No | Resolved |
| 2013-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2008-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Picloramcode 2040 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Oxamylcode 2036 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Endrincode 2005 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Simazinecode 2037 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Aldicarbcode 2047 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Alachlor (Lasso)code 2051 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dalaponcode 2031 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) adipatecode 2035 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbofurancode 2046 | No | Resolved |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Dering Harbor Water District: frequently asked questions
Who runs Dering Harbor Water District?
Dering Harbor Water District (PWSID NY5103700) is a community water system owned by a local government. It is regulated by the NY state drinking water program.
How many people does Dering Harbor Water District serve?
Dering Harbor Water District reports serving 14 people through 37 service connections in Suffolk County, New York.
Where does Dering Harbor Water District get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Dering Harbor Water District have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2014. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Dering Harbor Water District's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2014. For current results, consult the system's annual water quality report, EPA ECHO, or the NY state drinking water program.
Where can I find Dering Harbor Water District's water quality report?
As a community water system, Dering Harbor Water District must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Suffolk County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Suffolk County Water Authority | Suffolk | 1,100,000 | Community | Groundwater |
| South Huntington Water District | Suffolk | 81,760 | Community | Groundwater |
| Greenlawn Water District | Suffolk | 42,000 | Community | Groundwater |
| Riverhead Water District | Suffolk | 35,000 | Community | Groundwater |
| Dix Hills Water District | Suffolk | 34,522 | Community | Groundwater |
| Smithtown Water District | Suffolk | 19,635 | Community | Purchased groundwater |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Dering Harbor Water District, PWSID NY5103700, New York”, https://aquacensus.com/water-systems/new-york/dering-harbor-water-district-ny5103700 (data as of October 1, 2026).