Delaware Tap Water Quality Report
49 cities analyzed • 550,572 people served
Updated March 2026 • Data from EWG & EPA SDWIS
Most Common Contaminants in Delaware
| Contaminant | Found In | % of Cities |
|---|---|---|
| Radium, combined (-226 and -228) | 39 of 49 | 80% |
| Fluoride | 37 of 49 | 76% |
| Chloroform carcinogen | 35 of 49 | 71% |
| Nitrate and nitrite carcinogen | 34 of 49 | 69% |
| Bromodichloromethane carcinogen | 33 of 49 | 67% |
| Nitrate carcinogen | 32 of 49 | 65% |
| Total trihalomethanes (TTHMs) carcinogen | 32 of 49 | 65% |
| Dibromochloromethane carcinogen | 31 of 49 | 63% |
| Dichloroacetic acid carcinogen | 26 of 49 | 53% |
| Bromoform carcinogen | 22 of 49 | 45% |
City-by-City Water Quality Rankings
Ranked by number of contaminants above EWG health guidelines (most to fewest).
| # | City | Detected | Above Guidelines | Above Legal | People Served |
|---|---|---|---|---|---|
| 1 | Newark | 41 | 17 | 0 | 301,000 |
| 2 | Wilmington | 35 | 16 | 1 | 107,976 |
| 3 | Middletown | 42 | 16 | 0 | 17,700 |
| 4 | Smyrna | 26 | 16 | 1 | 11,813 |
| 5 | Dover | 28 | 15 | 0 | 39,491 |
| 6 | Dagsboro | 22 | 13 | 0 | 900 |
| 7 | Lewes | 15 | 12 | 1 | 3,000 |
| 8 | Ocean View | 20 | 12 | 0 | 2,073 |
| 9 | Springfield | 20 | 12 | 0 | 126 |
| 10 | Camden | 19 | 11 | 0 | 5,000 |
| 11 | Selbyville | 14 | 11 | 0 | 3,502 |
| 12 | Rehoboth Beach | 18 | 11 | 0 | 2,400 |
| 13 | Frankford | 18 | 11 | 1 | 1,000 |
| 14 | Millsboro | 15 | 10 | 0 | 6,863 |
| 15 | Milton | 13 | 10 | 0 | 3,200 |
| 16 | Bridgeville | 14 | 10 | 0 | 0 |
| 17 | New Castle | 13 | 9 | 0 | 5,364 |
| 18 | Bethany Beach | 14 | 9 | 0 | 1,000 |
| 19 | Greenwood | 12 | 9 | 0 | 973 |
| 20 | Hockessin | 9 | 9 | 1 | 60 |
| 21 | Milford | 13 | 8 | 0 | 9,800 |
| 22 | Seaford | 13 | 8 | 0 | 6,699 |
| 23 | Long Neck | 12 | 8 | 0 | 5,500 |
| 24 | Harrington | 13 | 8 | 0 | 3,562 |
| 25 | Laurel | 13 | 7 | 0 | 3,984 |
| 26 | Frederica | 9 | 7 | 0 | 950 |
| 27 | Magnolia | 11 | 7 | 0 | 498 |
| 28 | Winterthur | 7 | 7 | 0 | 0 |
| 29 | Felton | 16 | 6 | 0 | 1,591 |
| 30 | Georgetown | 10 | 6 | 0 | 749 |
| 31 | Salisbury | 8 | 6 | 0 | 360 |
| 32 | Elida | 9 | 6 | 0 | 195 |
| 33 | Blades | 9 | 5 | 0 | 1,200 |
| 34 | Pittsford | 9 | 5 | 0 | 476 |
| 35 | Clarksville | 8 | 5 | 0 | 115 |
| 36 | Delmar | 6 | 4 | 0 | 210 |
| 37 | Willow Street | 5 | 3 | 0 | 210 |
| 38 | Ridgely | 8 | 3 | 0 | 111 |
| 39 | Crofton | 4 | 3 | 0 | 75 |
| 40 | Rehoboth | 4 | 2 | 0 | 148 |
| 41 | Denton | 3 | 2 | 0 | 65 |
| 42 | New York | 2 | 2 | 0 | 65 |
| 43 | Cherry Hill | 5 | 2 | 0 | 32 |
| 44 | Hartly | 4 | 2 | 0 | 30 |
| 45 | Kenton | 2 | 1 | 0 | 123 |
| 46 | Annapolis | 3 | 1 | 0 | 117 |
| 47 | Wyoming | 2 | 1 | 0 | 110 |
| 48 | Camden-wyoming | 2 | 1 | 0 | 90 |
| 49 | Nassau | 2 | 1 | 0 | 66 |
Recommended Filtration for Delaware
Based on the most common contaminants found across Delaware (Radium, combined (-226 and -228), Fluoride, Chloroform), we recommend a reverse osmosis (RO) system for comprehensive contaminant removal.
Echo RO System
Removes up to 99.9% of contaminants. The gold standard for drinking water in Delaware homes.
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Shop Hydrogen FlaskFrequently Asked Questions
Is Delaware tap water safe to drink?
Water quality varies significantly across Delaware. Of the 49 cities analyzed, the average city has 7.5 contaminants above EWG health guidelines. The best water quality was found in Kenton. We recommend checking your specific city's report for detailed information.
What city has the best water in Delaware?
Based on our analysis, Kenton has the fewest contaminants above EWG health guidelines in Delaware, with 1 above guideline levels.
What city has the worst water in Delaware?
Based on our analysis, Newark has the most contaminants above EWG health guidelines in Delaware, with 17 above guideline levels.
What's the best water filter for Delaware residents?
For most Delaware households, we recommend a reverse osmosis (RO) system for drinking water and a whole-home filter for showers and baths. The specific recommendation depends on your city's contaminant profile — check your city's report for personalized guidance.
National Water Quality Reports
Data sources: Environmental Working Group (EWG) Tap Water Database, U.S. EPA Safe Drinking Water Information System (SDWIS)
Last updated: March 2026
Methodology: Contaminant levels are compared against both EPA legal limits (Maximum Contaminant Levels) and EWG health guidelines, which are often stricter and based on the latest scientific research.