Public water system · DE0000503
ActiveWinterthur
At a glance
Winterthur (PWSID DE0000503) is an active community water system in New Castle County, Delaware. It reports serving 687 people through 39 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2006.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
687
Service connections
39
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Winterthur compare with other water systems in New Castle County?
By EPA's size categories, Winterthur is a small system (501 to 3,300 people). New Castle County has 76 active public water systems. Its population served is well below the county average of 7,119 people per system, and accounts for 0.1% of the 541,043 people reported by systems filed under the county. Across Delaware, the 494 active systems average 2,238 people each. Nationally, the average active community water system reports serving 6,703 people, so Winterthur 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. Delaware has 219 active community water systems, 44% of the state's 494 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 459 Delaware systems (93%) list groundwater as their primary source.
Who owns and regulates Winterthur?
EPA lists Winterthur as privately owned. The DE state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 54 of the 76 active systems in New Castle County (71%) are also privately owned.
Does Winterthur have drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2006. The violations listed here began between October 1998 and October 2006. By type: 3 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 2 as archived and 1 as resolved. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status. 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 |
|---|---|---|---|---|
| 2006-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1998-10-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1998-10-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Archived |
All 3 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.
Winterthur: frequently asked questions
Who runs Winterthur?
Winterthur (PWSID DE0000503) is a community water system privately owned. It is regulated by the DE state drinking water program.
How many people does Winterthur serve?
Winterthur reports serving 687 people through 39 service connections in New Castle County, Delaware.
Where does Winterthur 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 Winterthur have any drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2006. 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 Winterthur'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. EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2006. For current results, consult the system's annual water quality report, EPA ECHO, or the DE state drinking water program.
Where can I find Winterthur's water quality report?
As a community water system, Winterthur 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 New Castle County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Artesian Water Company | New Castle | 231,114 | Community | Purchased surface water |
| Wilmington Water Department | New Castle | 107,976 | Community | Surface water |
| Veolia Water Delaware, Inc. | New Castle | 100,495 | Community | Surface water |
| Newark Water Department | New Castle | 40,000 | Community | Surface water |
| Middletown Water Department | New Castle | 17,700 | Community | Purchased surface water |
| Municipal Services Commission | New Castle | 5,549 | Community | 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, “Winterthur, PWSID DE0000503, Delaware”, https://aquacensus.com/water-systems/delaware/winterthur-de0000503 (data as of October 1, 2026).