California utilities with moderately hard water.

61 to 120 mg/L (3.6 to 7 grains per gallon). 414 utilities serving 465,877 people as they report it, largest first.

1 to 100 of 414, by people served

California utilities with moderately hard water, 1 to 100
Utility	Based in	Serves	Hardness, mg/L	Grains per gallon
North Marin Water District	Novato	61,691	111	6.5
City of Lincoln	Lincoln	56,268	87	5.1
City of Mountain House	Mountain House	26,400	84	4.9
Linda County Water District	Marysville	21,654	70	4.1
Twentynine Palms Water District	Twentynine Palms	18,795	67	3.9
City of American Canyon	American Canyon	18,423	98	5.7
Rosamond CSD	Rosamond	18,150	99	5.8
Coalinga - City	Coalinga	17,277	105	6.1
City of Red Bluff	Red Bluff	14,286	84	4.9
City of California City	California City	14,198	102	6
City of Avenal	Avenal	13,696	99	5.8
Plumas Lake	Olivehurst	11,374	100	5.8
Del Oro Water Co. - Paradise Pines	Chico	10,738	70	4.1
Ccwd - Jenny Lind	San Andreas	9,861	78	4.6
City of Susanville	Susanville	7,811	84	4.9
City of Dos Palos	Dos Palos	7,452	71	4.2
City of Huron	Huron	7,306	91	5.3
Los Angeles Cwwd 36 - Val Verde	Alhambra	6,712	97	5.7
City of Calistoga	Calistoga	5,610	80	4.7
Redwood Valley County Water District	Ukiah	5,200	78	4.5
Denair Community Services District	Denair	5,093	95	5.5
Northstar CSD - Martis Valley	Truckee	4,432	72	4.2
Lockeford Community Serv. Dist.	Lockeford	3,572	96	5.6
Valley State Prison	Chowchilla	3,151	94	5.5
Seaside Municipal Water System	Seaside	2,800	75	4.4
Trinity Co. W.W. Dist #1	Hayfork	2,324	89	5.2
Clawa	Crestline	2,320	88	5.1
Central CA Womens Facility	Chowchilla	2,046	90	5.3
Garberville Sanitary District	Garberville	2,041	110	6.5
Western Hills Water District/Diablo Gran	Patterson	2,000	105	6.1
Linden County Water District	Linden	1,784	77	4.5
Le Grand Comm Services Dist	Le Grand	1,739	106	6.2
Willow Creek C.S.D.	Willow Creek	1,720	93	5.4
Westwood C.S.D.	Westwood	1,662	65	3.8
Oakwood Lake Water District - Subdivision	Stockton	1,640	101	5.9
California Water Service Co. - Lancaster	San Jose	1,416	91	5.3
Arrowbear Park CWD	Arrowbear Lake	1,396	100	5.8
Kettleman City CSD	Kettleman City	1,242	90	5.2
Sbdno County Service Area 70 Cedar Glen	San Bernardino	1,240	73	4.3
Redway C.S.D.	Redway	1,207	120	7
Inyokern CSD	Inyokern	1,125	110	6.4
Bdvwa - Goat Mountain ID	Yucca Valley	1,118	100	5.8
Fallsvale Service Company	Forest Falls	1,046	90	5.2
Upper Lake County Water District	Upper Lake	989	108	6.3
San Joaquin County - Thornton	Stockton	964	82	4.8
Lawson S Landing	Dillon Beach	946	89	5.2
Psmcsd - Normco	Royal Oaks	928	71	4.2
Herlong Public Utility District	Herlong	831	93	5.4
Ivcsd - Greenville	Greenville	795	83	4.8
Los Angeles Cwwd 40, Reg. 35 - N.E. L.A.	Alhambra	792	93	5.4
Riverdale Village	Bakersfield	750	115	6.7
Shasta Forest Village M.W.C.	Shingletown	750	95	5.6
Trinity Center M.W.C.	Trinity Center	729	86	5
Sierra CSA #5, Sierra Brooks	Downieville	726	89	5.2
Lacsd - Rimforest	Lake Arrowhead	717	77	4.5
Humboldt Bay MWD	Eureka	680	77	4.5
Tokay Park Water Co	Sacramento	653	78	4.5
Julian Community Services District	Julian	617	106	6.2
Carver Tract Mutual Water Comp	Indio	600	98	5.7
S & T Mutual Water Company	Los Osos	591	110	6.4
MD 33 Fairmead	Madera	568	69	4
Patterson Tract CSD	Visalia	550	94	5.5
Calpella County Water District	Ukiah	548	103	6
Rio Vista Mobile Home Park	Sacramento	543	95	5.6
Sherwood Mobile Home Park	Lancaster	540	78	4.5
Whitehawk Ranch MWC	Clio	540	83	4.9
Armstrong Valley - Cal Water Service (Puc)	San Jose	539	98	5.7
North Tahoe PUD - Carnelian Woods	Tahoe Vista	524	86	5.1
Big Rock C.S.D.	Crescent City	513	75	4.4
Golden Era Productions	San Jacinto	500	101	5.9
Tract 92 Community Services District	Farmersville	500	83	4.9
The Lakes Association	Visalia	495	67	3.9
Miranda C.S.D.	Miranda	492	78	4.6
U.S. Coast Guard Training Center	Petaluma	469	110	6.4
Fcsa 32 - Cantua Creek	Fresno	468	96	5.6
Brock Mutual Water Company	Bakersfield	462	92	5.4
Gridley Farm Labor Housing	Chico	460	62	3.6
Point Arena Water Works	Point Arena	459	69	4
Golden Sands Mobile Home Park	Rosemead	450	114	6.7
Madera Mh & Rv Park	Madera	450	66	3.9
Weott C.S.D.	Weott	448	89	5.2
Fcsa 49 - Five Points	Fresno	440	95	5.6
El Rio Estates	Anderson	434	102	6
Stockdale Annex Mutual Water	Bakersfield	433	85	5
Sky View County Water	Paynes Creek	429	103	6
Delft Colony Water	Visalia	412	93	5.5
Sonoma County CSA 41 - Jenner	Santa Rosa	406	120	7
Cabana Holiday WS	Irvine	400	83	4.9
Butte Creek Estates Mutual Water Co	Chico	399	79	4.6
Forest Springs	Boulder Creek	385	120	7
Strawberry Lodge MWC	Twin Peaks	381	93	5.4
Willow Park Marina	Oakley	380	109	6.4
Bridgeport PUD	Bridgeport	374	84	4.9
Smiley Park Country Club	Running Springs	370	104	6.1
Green Acres Mobile Home Estate	Fresno	350	106	6.2
MD 37 la Vina	Madera	350	71	4.2
Yettem Water System	Visalia	350	108	6.3
Colonial Park	Healdsburg	342	97	5.7
Porterville - Jones Corner	Porterville	339	85	5
El Dorado Mobile Home Park	Laguna Hills	318	94	5.5

Source: California State Water Resources Control Board, Division of Drinking Water, 2,449 utilities, results from Jan. 2, 2019 to July 14, 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: 7 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 414, by people served

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