Delaware water hardness, by utility.

18 Delaware utilities serving 758,554 people as they report it, from the state’s own results. Hardness is the calcium and magnesium in water; EPA sets no limit for it.

The short answer

8 utilities serving 606,116 people have water in more than one band. Among those in one band, soft water reaches the most people: 7 utilities serving 124,438.

The largest, Artesian Water Company, is soft to very hard depending on the source, 9 to 361 mg/L (0.5 to 21.1 grains per gallon).

Moderately hard

61 to 120 mg/L (3.6 to 7 grains per gallon). 3 utilities serving 28,000 people, largest first.

Delaware utilities: moderately hard water
Utility	Based in	Serves	Hardness, mg/L	Grains per gallon
Bethany Beach Water Department	Bethany Beach	12,000	100	5.8
Dover Air Force Base	Dover AFB	11,000	102	6
Camden Wyoming Sewer and Water Authority	Camden - Wyoming	5,000	94	5.5

Soft

Up to 60 mg/L (3.5 grains per gallon). 7 utilities serving 124,438 people, largest first.

Delaware utilities: soft water
Utility	Based in	Serves	Hardness, mg/L	Grains per gallon
Rehoboth Pump District (Tui)	Rehoboth Beach	81,417	13	0.7
Long Neck Water Company	Millsboro	11,000	10	0.6
Millsboro Water Department	Millsboro	8,568	29	1.7
Georgetown Water Department	Georgetown	7,259	15	0.9
Seaford Water Department	Seaford	6,699	20	1.2
Artesian Northern Sussex Regional	Lewes	5,511	34	2
Laurel Water Department	Laurel	3,984	8.1	0.5

Varies

Water in more than one band, depending on where or when it was sampled: each is given as its range, softest to hardest, and its report says more. 8 utilities serving 606,116 people, largest first.

Delaware utilities: varies water
Utility	Based in	Serves	Hardness, mg/L	Grains per gallon
Artesian Water Company	Bear	231,114	9 to 361	0.5 to 21.1
Wilmington Water Department	Wilmington	107,976	51 to 62	3 to 3.6
Veolia Water Delaware, Inc	New Castle	100,495	73 to 150	4.3 to 8.8
Bethany Bay Pump District	Millville	52,684	10 to 104	0.6 to 6.1
Newark Water Department	Newark	40,000	42 to 71	2.5 to 4.1
Dover Water Department	Dover	39,491	23 to 117	1.3 to 6.8
Camden Pump District	Camden - Wyoming	17,208	7.8 to 137	0.5 to 8
Garrison Lake Pump District	Smyrna	17,148	8.5 to 68	0.5 to 4

Source: Delaware Division of Public Health, Office of Drinking Water, 18 utilities, results from Jan. 15, 2015 to Sept. 10, 2026, read Oct. 17, 2026. Each sampling point is taken at its median; a figure is typical where every point falls in one band.

Bands are the U.S. Geological Survey’s, at 17.1 mg/L to the grain. People served is what each utility reports; where one sells water to another, the same people can be counted twice. How hardness is measured here.

Moderately hard

Soft

Varies

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