Washington utilities with moderately hard water.

61 to 120 mg/L (3.6 to 7 grains per gallon). 501 utilities serving 1 million people as they report it, largest first.

1 to 100 of 501, by people served

Washington utilities with moderately hard water, 1 to 100
Utility	Based in	Serves	Hardness, mg/L	Grains per gallon
City of Redmond Water System	Redmond	163,335	94	5.5
Pasco Water Department	Pasco	115,102	74	4.3
Sno PUD 1 - Lake Stevens	Everett	67,710	82	4.8
Longview Water Department	Longview	57,617	110	6.4
Bonney Lake Water Department City	Buckley	43,371	114	6.7
City of Pullman Water Department	Pullman	31,315	113	6.6
City of Mercer Island	Mercer Island	31,057	83	4.9
East Wenatchee Water District	East Wenatchee	26,519	72	4.2
Vera Water & Power	Spokane Valley	24,692	84	4.9
North Perry Ave Water District	Bremerton	24,402	94	5.5
Ridgefield Public Works	Ridgefield	21,225	97	5.7
King County Water District No 90	Renton	20,100	75	4.4
City of Poulsbo	Poulsbo	18,400	68	3.9
Olympic View Water & Sewer District	Edmonds	17,784	110	6.4
City of Yelm	Yelm	17,355	66	3.9
Naval Base Kitsap at Bangor	Silverdale	16,828	72	4.2
City of Sumner	Sumner	16,438	98	5.7
Fruitland Mutual Water Company	Puyallup	15,313	103	6
City of Shelton	Shelton	15,273	62	3.6
City of Dupont Water System	Dupont	13,141	68	4
Skyway Water & Sewer	Seattle	12,036	112	6.5
City of Woodland	Woodland	10,640	87	5.1
NE Sammamish Sewer & Water District	Sammamish	9,702	69	4
Mountain View - Edgewood Water Co	Edgewood	9,680	102	6
North Beach Water	Ocean Park	8,093	69	4
Tanglewilde Thompson Place 600	Lacey	7,900	71	4.2
Buckley Water	Buckley	7,842	88	5.1
City of Montesano	Montesano	6,204	62	3.6
Seven Lakes Water Association	Stanwood	5,823	81	4.7
City of Mattawa	Mattawa	5,370	61	3.6
Water District 19	Vashon	5,335	99	5.8
Point Evans	Tacoma	5,211	75	4.4
City of Medical Lake	Medical Lake	4,982	96	5.6
Suquamish	Poulsbo	4,203	83	4.9
Granger Water Department	Granger	3,993	95	5.5
City of Everson	Everson	3,893	80	4.7
Town of Friday Harbor	Friday Harbor	3,543	73	4.3
Dayton Water Department	Dayton	3,374	94	5.5
Ames Lake Water Assoc Inc	Redmond	3,224	80	4.6
Strohs	Tacoma	3,192	84	4.9
Meadows 690	Lacey	3,100	76	4.4
Olympic Water & Sewer Inc	Port Ludlow	3,086	73	4.3
Fall City Water Dist. #127	Fall City	2,987	111	6.5
Cedar Crest	Tacoma	2,954	92	5.4
Desert Aire Owner Assn	Desert Aire	2,856	85	5
City of McCleary	McCleary	2,753	81	4.7
Asotin Water Dept	Asotin	2,531	69	4
Chelan Co PUD - Chelan Ridge	Wenatchee	2,429	60	3.5
Cherokee Bay Community Club Inc	Port Orchard	2,400	94	5.5
Timberlake Community Club Inc	Shelton	2,337	68	4
Valley Water System	Puyallup	2,259	70	4.1
Alpine Water District	Cashmere	2,255	73	4.3
Hutchinson Irrigation Dist #16	Spokane Valley	2,209	76	4.5
Sandy Point Improvement Co	Lynden	2,098	91	5.3
Roche Harbor Water System Inc	Friday Harbor	2,091	80	4.7
View Royal Water System	Puyallup	2,069	114	6.7
Heights Water	Vashon	2,051	106	6.2
Clinton Water District	Clinton	1,980	80	4.7
Skagit Co Water District #1	MT Vernon	1,974	90	5.3
Pole Road Water Association	Lynden	1,960	96	5.6
Toledo Municipal	Toledo	1,944	66	3.9
Palmer Lake	Tacoma	1,924	70	4.1
City of Waitsburg	Waitsburg	1,817	113	6.6
City of Electric City	Electric City	1,812	111	6.5
Indianola Water	Poulsbo	1,705	94	5.5
Carnhope Irrigation District 7	Spokane Valley	1,602	119	7
Coulee Dam Water Dept	Coulee Dam	1,454	60	3.5
Graham Hill Mutual Water Co Inc	Graham	1,440	94	5.5
Rosario	Eastsound	1,426	86	5
City of Langley	Langley	1,416	95	5.5
Lake Josephine Riviera	Anderson Island	1,380	78	4.5
Harrah Water System	Harrah	1,304	120	7
Diamond Lake Water & Sewer District	Newport	1,299	118	6.9
Walla Walla University	Walla Walla	1,273	64	3.7
Bc Water Co	Kennewick	1,262	84	4.9
Keyport Water	Poulsbo	1,202	76	4.4
Warm Beach Conference Grounds	MT Vernon	1,190	87	5.1
Lewis Co Water Dist #1	Napavine	1,174	94	5.5
Town of Twisp	Twisp	1,173	83	4.9
Meadowmeer	Port Orchard	1,157	95	5.6
Miller Bay	Poulsbo	1,072	114	6.6
Wilkeson Water Department	Wilkeson	1,071	101	5.9
Fawn Lake Maintenance Comm	Shelton	1,044	68	4
Dockton Water Association	Vashon	992	84	4.9
The Buttes	Puyallup	973	98	5.7
Cape Horn Maintenance Company	MT Vernon	940	100	5.8
Lyle Water System	Goldendale	938	90	5.3
Country/Eldorado Water System	Puyallup	915	92	5.4
Town of Rosalia	Rosalia	831	103	6
Diamond Point	Freeland	810	98	5.7
Veterans Affair Med Ctr Dept of	Yakima	785	75	4.4
Scenic Shores Water Company	Port Orchard	761	87	5.1
Stevens Co PUD - Clayton	Loon Lake	725	73	4.3
Garfield Water Department	Tekoa	694	100	5.8
Town of Cusick	Cusick	672	89	5.2
Bywater Bay	Port Townsend	628	94	5.5
Lacamas Farmsteads	Tacoma	615	90	5.3
Albion Water Dept	Albion	600	111	6.5
Jefferson County Water Dist #1	Port Ludlow	600	63	3.7
McKenna Water District	McKenna	600	78	4.6

Source: Washington State Department of Health, Office of Drinking Water, 1,479 utilities, results from Jan. 7, 2020 to Sept. 22, 2026, read Oct. 10, 2026. Each sampling point is taken at its median; a figure is typical where every point falls in one band.

Also: 2 utilities’ own water quality reports, read by hand, each named on the utility’s page.

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.

1 to 100 of 501, by people served

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