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Community Water System · PWS DE0000622

Millsboro Water Department

Millsboro, Delaware 19966 - drinking water served from groundwater sources to 8,568 people, tracked in EPA SDWIS and UCMR5.

8,568
People served
25
EPA violations
5
Health-based
No PFAS
UCMR5 result

The verdict

EPA records 25 drinking-water violations at Millsboro Water Department, 20% of them health-based - above the Delaware per-system average.

25
Total EPA violations on record
20%
Health-based (MCL / treatment failure)
8,568
People served by this system
0
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Millsboro Water Department

Millsboro Water Department is a local-owned community water system that delivers drinking water to 8,568 residents in Millsboro, Delaware (Sussex County) through 5,494 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 25 total violations for this system , of which 5 (20%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 6 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.

The most frequently cited contaminant at this system is Consumer Confidence Rule, recorded in 5 violations (Other). This system was sampled under EPA's UCMR5 PFAS monitoring program and no PFAS compounds were detected above the minimum reporting level.

Across Delaware, EPA tracks 460 public water systems serving 1,083,630 people, with 9,105 cumulative violations and 4,582 health-based violations on record. About 75% of systems in the state carry at least one violation, and state-wide the average per system is 19.8 violations. Statewide, 25 of 35 UCMR5-tested systems have reported PFAS detections (71.4%).

Millsboro Water Department's 25 violations sit above the Delaware 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
8,568
Total Violations
25
Health-Based Violations
5
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
5,494
County
Sussex
School/Daycare
No
MCL Violations
5
Monitoring Violations
6
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Consumer Confidence Rule Other 5 2017
Trichloroethylene MCL 3 2005
Coliform (TCR) MR 3 2006
Lead and Copper Rule MR 3 2024
Coliform (TCR) MCL 2 1991

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 58 samples detected PFAS.

Contaminant Date Result MRL Status
PFEESA 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
HFPO-DA 5/15/2024 <5.00 ppt 5.00 ppt Not Detected
PFBA 5/15/2024 <5.00 ppt 5.00 ppt Not Detected
6:2 FTS 5/15/2024 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 5/15/2024 <5.00 ppt 5.00 ppt Not Detected
PFMPA 5/15/2024 <4.00 ppt 4.00 ppt Not Detected
PFPeS 5/15/2024 <4.00 ppt 4.00 ppt Not Detected
PFMBA 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
NFDHA 5/15/2024 <20.00 ppt 20.00 ppt Not Detected
ADONA 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
PFOS 5/15/2024 <4.00 ppt 4.00 ppt Not Detected
PFHpS 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
PFPeA 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
PFHxS 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
NMeFOSAA 5/15/2024 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 5/15/2024 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 5/15/2024 <7.00 ppt 7.00 ppt Not Detected
PFTA 5/15/2024 <8.00 ppt 8.00 ppt Not Detected
PFDA 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
PFHpA 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 5/15/2024 <2.00 ppt 2.00 ppt Not Detected
PFNA 5/15/2024 <4.00 ppt 4.00 ppt Not Detected
PFOA 5/15/2024 <4.00 ppt 4.00 ppt Not Detected
PFDoA 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
PFHxA 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
PFUnA 5/15/2024 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 5/15/2024 <5.00 ppt 5.00 ppt Not Detected
PFBS 5/15/2024 <3.00 ppt 3.00 ppt Not Detected
PFUnA 11/4/2024 <2.00 ppt 2.00 ppt Not Detected
PFDoA 11/4/2024 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 11/4/2024 <2.00 ppt 2.00 ppt Not Detected
PFHpA 11/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFHxS 11/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFNA 11/4/2024 <4.00 ppt 4.00 ppt Not Detected
PFOS 11/4/2024 <4.00 ppt 4.00 ppt Not Detected
PFDA 11/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFHxA 11/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFBS 11/4/2024 <3.00 ppt 3.00 ppt Not Detected
11Cl-PF3OUdS 11/4/2024 <5.00 ppt 5.00 ppt Not Detected
ADONA 11/4/2024 <3.00 ppt 3.00 ppt Not Detected
HFPO-DA 11/4/2024 <5.00 ppt 5.00 ppt Not Detected
PFBA 11/4/2024 <5.00 ppt 5.00 ppt Not Detected
PFPeS 11/4/2024 <4.00 ppt 4.00 ppt Not Detected
NMeFOSAA 11/4/2024 <6.00 ppt 6.00 ppt Not Detected
PFOA 11/4/2024 <4.00 ppt 4.00 ppt Not Detected
6:2 FTS 11/4/2024 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 11/4/2024 <7.00 ppt 7.00 ppt Not Detected
PFTA 11/4/2024 <8.00 ppt 8.00 ppt Not Detected
NEtFOSAA 11/4/2024 <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 Millsboro 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 DE0000622 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Delaware Drinking Water Authority

Delaware's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find DE regulator via EPA SDWIS

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
2024 Lead and Copper Rule MR 3 SDWIS / DE0000622 / 5000
2017 Consumer Confidence Rule Other 5 SDWIS / DE0000622 / 7000
2006 Coliform (TCR) MR 3 SDWIS / DE0000622 / 3100
2005 Trichloroethylene MCL 3 SDWIS / DE0000622 / 2984
1991 Coliform (TCR) MCL 2 SDWIS / DE0000622 / 3100

How Millsboro Water Department Compares

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

Metric Millsboro Water Department Delaware avg Federal benchmark
Total violations 25 19.8 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 5 10 Indicates a contaminant exceeded a federal MCL
PFAS detection None 71.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 8,568 2,356 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 460 regulated public water systems in Delaware.

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 Millsboro Water Department water safe to drink?
Millsboro Water Department (PWS ID: DE0000622) has 25 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 8,568 people using Groundwater sources.
How many people does Millsboro Water Department serve?
Millsboro Water Department serves 8,568 people in Millsboro, Delaware. It is a Local-owned system using Groundwater water sources with 5,494 service connections.
What type of violations does Millsboro Water Department have?
Millsboro Water Department has 25 total violations: 5 health-based violations (MCL exceedances or treatment failures), 6 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Millsboro Water Department water?
No. Millsboro Water Department was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.
What water source does Millsboro Water Department use?
Millsboro Water Department 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.
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.