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EWG's Tap Water Database — 2019 UPDATE

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Perchlorate

Status: No national drinking water standard exists

 

Perchlorate, a component of rocket fuel, occurs both naturally and as a synthetic chemical. Ingested perchlorate interferes with thyroid function. Exposure to perchlorate during pregnancy and childhood can impair cognitive development. Read More.

According to the EPA, perchlorate likely contaminates the water of more than 16 million Americans. Perchlorate interferes with iodine uptake in the thyroid, which can result in reduced thyroid hormones and an impact on metabolism, physical development and cognitive development. Children and developing fetuses are the most at risk from perchlorate contamination.

Perchlorate is the only unregulated contaminant for which the EPA has attempted to set a federal drinking water standard since 1996. However, the agency has yet to propose a draft limit for this contaminant. Perchlorate in drinking water is regulated in Arizona, California, Massachusetts, New Jersey, New York and Texas. California set a public health goal of 1 part per billion for perchlorate in 2015.

Click here to read more about perchlorate.

2015-2017:

FOUND
FOUND ABOVE HEALTH GUIDELINES

7

states detected

375

utilities detected

12 million

people served

3

states over health guideline

44

utilities over health guideline

871,000

people served over health guideline

Health concerns for perchlorate

Hormone disruption

Harm to fetal growth and child development

State and national drinking water standards and health guidelines

EWG Health Guideline 1 ppb

The EWG Health Guideline of 1 ppb for perchlorate was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against hormone disruption.

ppb = parts per billion

States reporting perchlorate in drinking water

UTILITIES REPORTING ABOVE HEALTH GUIDELINES UTILITIES WITH CONTAMINATION
State UtilitiesPeople Served UtilitiesPeople Served
California28380,007894,626,559
Massachusetts24,4892423,052,753
New York14486,510352,306,067
Virginia0031,289,499
District Of Columbia003648,882
North Carolina001128,800
Rhode Island0018,969
Vermont00160
MORE
LESS

Filtering technologies that reduce perchlorate

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Reverse Osmosis

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Ion Exchange

Utilities with the highest amounts of perchlorate, 2015-2017

ALL UTILITIES
LARGE UTILITIES
UtilityLocationTestsAverage levelPeople served
Kern Valley State PrisonDelano, CA2 of 217.4 ppb5,300
La Verne WDLa Verne, CA180 of 2306.63 ppb32,230
Riverhead WD*Riverhead, NY3 of 35.10 ppb35,000
Riverside Water DistrictOakdale, NY3 of 35.10 ppb2,050
Castaic Lake Water Agency*Santa Clarita, CA687 of 2,5724.55 ppb0
Marygold Mutual Water CompanyBloomington, CA8 of 114.06 ppb3,449
City Of EtnaEtna, CA1 of 14.00 ppb769
Tierra Buena Mobile Home Park #1Marysville, CA10 of 123.71 ppb50
Westbury WDWestbury, NY29 of 453.52 ppb20,500
Locust Valley Water DistrictLocust Valley, NY14 of 193.42 ppb7,500
Fairview Water Company LLCTehachapi, CA53 of 1303.20 ppb240
Page Avenue Mutual Water CompanyFullerton, CA9 of 133.13 ppb115
Plainview WDPlainview, NY309 of 4262.90 ppb35,000
Loma Linda Power PlantLoma Linda, CA17 of 242.67 ppb10,500
Hynes Estates Mutual Water CompanyAnaheim, CA9 of 182.57 ppb120
Santa Ynez Roblar Mobile Home ParkLa Canada, CA1 of 12.50 ppb45
Bethpage WDBethpage, NY288 of 4732.47 ppb33,000
Palms River ResortHemet, CA1 of 22.35 ppb200
Ontario Municipal Utilities CompanyOntario, CA43 of 442.27 ppb167,382
Town of Hempstead Water DepartmentEast Meadow, NY39 of 642.21 ppb110,000
Las Flores Water CompanyAltadena, CA133 of 3052.08 ppb4,500
City of ChinoChino, CA129 of 6152.07 ppb18,907
Stallion Springs Community Services DistrictTehachapi, CA40 of 1202.02 ppb2,488
Saticoy Country Club-city Of VenturaVentura, CA2 of 52.00 ppb150
Lemon Cove Water CompanyLemon Cove, CA1 of 12.00 ppb200
Hicksville WDHicksville, NY363 of 4701.88 ppb48,000
Roslyn WD*Roslyn, NY3 of 41.88 ppb18,000
Glenwood Water DistrictGlenwood Landing, NY3 of 41.88 ppb1,000
South Huntington Water DepartmentSouth Huntington, NY3 of 31.68 ppb81,760
Jericho Water DistrictSyosset, NY62 of 1111.64 ppb58,000
Glen Cove CityGlen Cove, NY27 of 331.58 ppb28,000
Calif State Polytechnical Univ - PomonaPomona, CA61 of 2381.55 ppb24,880
Western MWD (Arlington)*Riverside, CA29 of 1021.50 ppb0
Carpinteria Valley Water DistrictCarpinteria, CA1 of 21.50 ppb16,050
Valencia Heights Water CompanyWest Covina, CA56 of 2471.34 ppb5,500
West San Martin Water Works Inc.San Martin, CA42 of 851.30 ppb1,403
San Martin County Water DistrictMorgan Hill, CA28 of 951.22 ppb614
Herring Cove Condominiums TrustPlymouth, MA28 of 361.19 ppb25
Redlands CityRedlands, CA354 of 7721.16 ppb80,000
Sturbridge Water DepartmentSturbridge, MA116 of 1211.16 ppb4,464
Yerba Buena Water CompanyPaso Robles, CA1 of 71.14 ppb690
Yuima Municipal Water District IdaPauma Valley, CA43 of 2091.08 ppb400
Oyster Bay Water DistrictOyster Bay, NY6 of 131.01 ppb8,700
Garden CityGarden City, NY16 of 420.986 ppb46,000
Charlton Street ApartmentsOxford, MA9 of 90.954 ppb33
Azusa Light and WaterAzusa, CA47 of 3970.860 ppb110,000
WA of Great Neck NorthGreat Neck, NY17 of 500.790 ppb31,400
City of Upland*Upland, CA11 of 660.789 ppb78,791
Yuima Municipal Water District*Pauma Valley, CA2 of 110.782 ppb260
Rubidoux Community SDRubidoux, CA20 of 1200.751 ppb26,150

* This water utility supplies finished drinking water to at least one other water utility. The purchasing utility is not required to test for or report Perchlorate, but it likely has the contaminant in its water supply.

UtilityLocationTestsAverage levelPeople served
La Verne WDLa Verne, CA180 of 2306.63 ppb32,230
Riverhead WD*Riverhead, NY3 of 35.10 ppb35,000
Westbury WDWestbury, NY29 of 453.52 ppb20,500
Plainview WDPlainview, NY309 of 4262.90 ppb35,000
Loma Linda Power PlantLoma Linda, CA17 of 242.67 ppb10,500
Bethpage WDBethpage, NY288 of 4732.47 ppb33,000
Ontario Municipal Utilities CompanyOntario, CA43 of 442.27 ppb167,382
Town of Hempstead Water DepartmentEast Meadow, NY39 of 642.21 ppb110,000
City of ChinoChino, CA129 of 6152.07 ppb18,907
Hicksville WDHicksville, NY363 of 4701.88 ppb48,000
Roslyn WD*Roslyn, NY3 of 41.88 ppb18,000
South Huntington Water DepartmentSouth Huntington, NY3 of 31.68 ppb81,760
Jericho Water DistrictSyosset, NY62 of 1111.64 ppb58,000
Glen Cove CityGlen Cove, NY27 of 331.58 ppb28,000
Calif State Polytechnical Univ - PomonaPomona, CA61 of 2381.55 ppb24,880
Carpinteria Valley Water DistrictCarpinteria, CA1 of 21.50 ppb16,050
Redlands CityRedlands, CA354 of 7721.16 ppb80,000
Garden CityGarden City, NY16 of 420.986 ppb46,000
Azusa Light and WaterAzusa, CA47 of 3970.860 ppb110,000
WA of Great Neck NorthGreat Neck, NY17 of 500.790 ppb31,400
City of Upland*Upland, CA11 of 660.789 ppb78,791
Rubidoux Community SDRubidoux, CA20 of 1200.751 ppb26,150
MineolaMineola, NY23 of 640.694 ppb20,600
Manhasset Lakeville WD*Great Neck, NY3 of 90.676 ppb44,600
Falmouth Water DepartmentFalmouth, MA9 of 170.669 ppb77,500
West Springfield Dpw Water DivisionWest Springfield, MA1 of 10.563 ppb28,391
San Bernardino City*San Bernardino, CA509 of 9640.561 ppb188,931
Golden State Water Company - West OrangeAnaheim, CA7 of 630.560 ppb114,016
Cal/Am Water Company - San MarinoRosemead, CA22 of 1840.559 ppb40,804
City of Corona*Corona, CA40 of 4880.532 ppb155,896
Smithtown WDKings Park, NY3 of 30.525 ppb19,635
Suffolk County Water Authority*Oakdale, NY3 of 30.525 ppb1,100,000
St James WDSt James, NY3 of 30.525 ppb10,587
Water Authority of Western NassauFloral Park, NY4 of 110.518 ppb120,000
Monrovia Water DepartmentMonrovia, CA31 of 3290.516 ppb36,590
Monte Vista Water District*Montclair, CA44 of 4430.505 ppb54,460
D.C. Water and Sewer Authority*Washington, DC69 of 710.465 ppb632,323
Arlington County*Arlington, VA69 of 710.465 ppb215,000
Rockport Water DepartmentRockport, MA7 of 70.455 ppb10,000
Jurupa Community Services District*Jurupa Valley, CA10 of 1140.409 ppb106,907
Camrosa Water DistrictCamarillo, CA1 of 50.400 ppb30,000
Suburban Water Systems - San Jose HillsCovina, CA10 of 1100.396 ppb162,031
City of Santa AnaSanta Ana, CA7 of 790.392 ppb329,815
Tewksbury Water DepartmentTewksbury, MA3 of 30.373 ppb29,855
West Valley Water District*Rialto, CA44 of 5850.364 ppb72,647
Gardner Water DepartmentGardner, MA6 of 60.325 ppb19,133
Swansea Water DistrictSwansea, MA18 of 180.320 ppb17,358
New York American Water - Sea CliffMerrick, NY10 of 380.300 ppb13,400
Lowell Regional Water Utility*Lowell, MA3 of 30.293 ppb106,519
Billerica Water WorksBillerica, MA3 of 30.284 ppb40,243

* This water utility supplies finished drinking water to at least one other water utility. The purchasing utility is not required to test for or report Perchlorate, but it likely has the contaminant in its water supply.