PFAS above a 2024 limit
MCL5of 9 cities
Cities whose system reported a PFAS above its federal limit.
PFOS in Delaware →State water report
Delaware Water Quality: 9 Cities Ranked by the Records
Water quality across 9 cities in Delaware, drawn from EPA drinking-water records. Each city page shows the measured contaminants and a reproducible Purity Score.
Finding by finding
What Delaware's records show
Counts of cities whose serving system reported each result. There is no statewide score: PurityMap does not average local records into a statewide safety verdict.
Lead detected
Action level3of 9 cities
90th-percentile lead above zero.
Lead across Delaware →Lead above action level
Action level0of 9 cities
No city on record above 15 µg/L.
How lead is measured →City rankings
Delaware cities ranked by the records
Highest first. A summary of each serving system’s record, not a safety verdict.
- 1MiddletownMIDDLETOWN WATER DEPARTMENT · DE0000614Report →
- 2Camden Pump DistrictCAMDEN PUMP DISTRICT · DE0000124Report →
- 3DoverDOVER WATER DEPARTMENT · DE0000571Report →
- 4Bethany BeachBETHANY BEACH WATER DEPARTMENT · DE0000556Report →
- 5Dewey BeachDEWEY BEACH WATER DEPARTMENT · DE0000825Report →
- 6Rehoboth BeachREHOBOTH BEACH WATER DEPARTMENT · DE0000723Report →
- 7SmyrnaSMYRNA WATER DEPARTMENT · DE0000657Report →
- 8WilmingtonWILMINGTON WATER DEPARTMENT · DE0000663Report →
- 9NewarkNEWARK WATER DEPARTMENT · DE0000630Report →
Showing the top 9 of 9 scored cities.
Highest detected PFOS result first. The tick marks the 4.0 ng/L federal MCL.
Highest 90th-percentile result first. The tick marks the 15 µg/L action level.
See all 9 in the table
9 cities, highest Purity Score first
- MIDDLETOWN WATER DEPARTMENT · PWSID DE0000614 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system levelNo PFAS detectedNot detected
- CAMDEN PUMP DISTRICT · PWSID DE0000124 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system levelNo PFAS detectedNot detected
- DOVER WATER DEPARTMENT · PWSID DE0000571 · Purity Score 98/100 (Excellent) · Confidence: moderate · Assessed at the water-system levelNo PFAS detected; lead 2 µg/LDetected
- BETHANY BEACH WATER DEPARTMENT · PWSID DE0000556 · Purity Score 94/100 (Excellent) · Confidence: moderate · Assessed at the water-system levelNo PFAS detected; lead 4.9 µg/LDetected
- DEWEY BEACH WATER DEPARTMENT · PWSID DE0000825 · Purity Score 57/100 (Fair) · Confidence: moderate · Assessed at the water-system levelPFOA 11 ng/L, 3× the EPA limitAbove reference
- REHOBOTH BEACH WATER DEPARTMENT · PWSID DE0000723 · Purity Score 57/100 (Fair) · Confidence: moderate · Assessed at the water-system levelPFOA 14.9 ng/L, 4× the EPA limit (+1 more PFAS above)Above reference
- SMYRNA WATER DEPARTMENT · PWSID DE0000657 · Purity Score 57/100 (Fair) · Confidence: moderate · Assessed at the water-system levelPFOA 9.8 ng/L, 2× the EPA limit (+1 more PFAS above)Above reference
- WILMINGTON WATER DEPARTMENT · PWSID DE0000663 · Purity Score 56/100 (Fair) · Confidence: moderate · Assessed at the water-system levelPFOA 9.9 ng/L, 2× the EPA limitAbove reference
- NEWARK WATER DEPARTMENT · PWSID DE0000630 · Purity Score 56/100 (Fair) · Confidence: moderate · Assessed at the water-system levelPFOA 25.3 ng/L, 6× the EPA limit (+1 more PFAS above)Above reference
End of list.
Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no state score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works. See how Delaware compares with other states.
By contaminant
PFAS and lead in Delaware
PFAS
MCLHighest detected PFOS result, by city.
- Newark7.5 ng/L
- Smyrna6.7 ng/L
- Rehoboth Beach6.2 ng/L
| 4.0 ng/L federal MCL · 3 cities above it
Lead
Action level90th-percentile result, by city.
- Bethany Beach4.9 µg/L
- Dover2 µg/L
- Newark1 µg/L
| 15 µg/L action level · none above
Counties
3 counties with city reportsDelaware counties
- New Castle County3 cities
- Kent County2 cities
- Sussex County1 city
Suppliers
Largest water systems
- WILMINGTON WATER DEPARTMENTWilmington · DE0000663 · 107,976 served
- NEWARK WATER DEPARTMENTNewark · DE0000630 · 40,000 served
- DOVER WATER DEPARTMENTDover · DE0000571 · 39,491 served
- DEWEY BEACH WATER DEPARTMENTDewey Beach · DE0000825 · 31,000 served
- REHOBOTH BEACH WATER DEPARTMENTRehoboth Beach · DE0000723 · 25,000 served
- MIDDLETOWN WATER DEPARTMENTMiddletown · DE0000614 · 17,700 served
Full indexAll 9 Delaware city reports, A–Z
Next step
State patterns can’t tell you what reaches your tap.
Learn
Learn your supplier
Resolve your address to the one public water system that serves it.
Find my water →Test
Test your own tap
Plumbing inside a building can add lead and change what reaches your glass.
How to test →Solve
Treat by concern
Only after a city report names a finding, match a treatment certified for it.
Treatment options →Questions
Delaware water, frequently asked
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How does Delaware tap water compare across cities?
PurityMap ranks 9 cities in Delaware by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Middletown's main water system: MIDDLETOWN WATER DEPARTMENT · PWSID DE0000614 · Purity Score 100 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.
How many Delaware cities have PFAS above the federal limit?
5 cities of 9 had at least one regulated PFAS (PFOA, PFOS or PFHxS) measured above the 2024 federal limit in EPA's UCMR 5 testing, including Newark (PFOA 25.3 ng/L), Rehoboth Beach (PFOA 14.9 ng/L), Dewey Beach (PFOA 11 ng/L). PFAS were detected at any level in 5.
Is there lead in Delaware tap water?
Utilities report lead as a 90th-percentile result from home taps. 3 of 9 Delaware cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.
Limits, sources and corrections
A statewide page cannot tell you what reaches a specific address. Water quality varies by supplier, sampling period and household plumbing; open a city report for the evidence behind a local result.
Sources: EPA UCMR 5 (PFAS, 2024), SDWIS Lead and Copper Rule 90th-percentile results and health-based violations, and utility Consumer Confidence Reports where on file. Every city report links its dated source records.
Updated 2026-09-16. How PurityMap analyzes water data · Report an error