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EWG's Tap Water Database — 2019 UPDATE

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Chlorate

Status: No national drinking water standard exists

 

Chlorate forms in drinking water as a byproduct of disinfection. Chlorate impairs thyroid function, making chlorate exposure most harmful during pregnancy and childhood. Read More.

In 2002, California scientists proposed an advisory value, called an action level, for chlorate at 200 parts per billion. Between 2013 and 2015, the EPA collected data through the Unregulated Contaminant Monitoring Rule program and found that over 15 percent of water tests from 38 percent of utilities had chlorate levels above a health-protective concentration, which federal scientists defined as 210 parts per billion, nearly equivalent to the California advisory value.

Click here to read more about disinfection byproducts.

2012-2017:

FOUND
FOUND ABOVE HEALTH GUIDELINES

50

states detected

5,935

utilities detected

205 million

people served

45

states over health guideline

1,563

utilities over health guideline

43 million

people served over health guideline

Health concerns for chlorate

Hormone disruption

State and national drinking water standards and health guidelines

EWG Health Guideline 210 ppb

The EWG Health Guideline of 210 ppb for chlorate was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against hormone disruption.

ppb = parts per billion

States reporting chlorate in drinking water

UTILITIES REPORTING ABOVE HEALTH GUIDELINES UTILITIES WITH CONTAMINATION
State UtilitiesPeople Served UtilitiesPeople Served
California955,241,85852937,276,612
New York25625,96426117,717,686
Texas2093,910,93458216,754,997
Florida22410,238,20031415,999,041
New Jersey28711,4852198,152,235
Pennsylvania151,747,7842307,195,975
Ohio44819,6001846,570,853
Georgia331,572,9461326,396,291
Virginia873,365,7711355,996,712
North Carolina1072,045,5393395,695,023
Arizona8157,554865,424,561
Massachusetts34944,5251795,307,349
Maryland12241,834504,879,105
Tennessee41954,7931444,407,949
Washington596,3491574,227,554
Alabama881,274,4501793,902,883
Illinois61460,8542293,627,881
Kentucky51876,5331753,269,784
Colorado16537,2241303,126,908
South Carolina711,085,4611592,894,865
Connecticut11111,900682,459,090
Nevada00192,416,374
Wisconsin899,356802,305,400
Indiana281,213,347602,235,142
Oregon17686,379682,198,122
Missouri35326,417742,185,001
Louisiana28930,575762,130,706
Michigan11170,5871051,932,706
Utah00511,761,736
Oklahoma46443,6891301,598,823
Kansas18164,667741,354,527
Iowa16173,8781391,297,716
Arkansas15364,9981041,279,429
Minnesota678,458341,238,539
New Mexico355,102281,203,158
Hawaii11,310161,199,384
Nebraska00271,098,127
Idaho0018687,440
Delaware5155,86114681,201
District Of Columbia4664,5724664,572
West Virginia234,31176621,272
Rhode Island350,18924590,913
New Hampshire8152,66043588,085
Mississippi353,64719505,913
Alaska8135,72419435,364
Maine445,77819414,363
South Dakota0052370,689
Wyoming1161,06535226,163
Montana120,0088175,744
Vermont1697,20134150,888
North Dakota179241,336
MORE
LESS

Utilities with the highest amounts of chlorate, 2012-2017

ALL UTILITIES
LARGE UTILITIES
UtilityLocationTestsAverage levelPeople served
Vc/halifax Plantation (wtp-8)Ormond Beach, FL4 of 42,530.0 ppb4,419
City of BonhamBonham, TX8 of 82,031.9 ppb10,123
Oak Shores Water SystemMontague, TX3 of 41,867.5 ppb228
VC/Southwest Water SystemOrange City, FL12 of 121,735.0 ppb20,725
SavageSavage, MN3 of 61,687.7 ppb26,911
AtkinsonAtkinson, IL4 of 41,432.9 ppb1,001
Willingboro MUA*Willingboro, NJ8 of 81,379.0 ppb35,000
Pennsville Twsp. Water Depart.Pennsville, NJ7 of 81,316.4 ppb13,500
Danvers Water Department*Middleton, MA11 of 111,244.5 ppb35,480
Middleton Water DepartmentMiddleton, MA11 of 111,244.5 ppb6,138
Garden City PWSGarden City, MO7 of 71,211.4 ppb1,642
Marshall County Water CorpMadill, OK8 of 101,161.6 ppb14,717
Houma Water Treatment Service AreaHouma, LA8 of 81,103.8 ppb31,560
Westwood BeachPflugerville, TX6 of 61,096.5 ppb1,734
Seminole County NortheastLake Mary, FL8 of 81,052.7 ppb18,462
St. MarysSt. Marys, GA5 of 61,047.7 ppb17,270
City of Terrell*Terrell, TX8 of 81,040.9 ppb24,744
Elmo Water Supply CorporationElmo, TX8 of 81,040.9 ppb2,280
Lawrence Water Supply CorporationTerrell, TX8 of 81,040.9 ppb837
Poetry Water Supply CorporationTerrell, TX8 of 81,040.9 ppb3,276
Alco Water ServiceSalinas, CA6 of 71,021.7 ppb29,179
Westside Rural Water Supply CorporationPflugerville, TX10 of 121,009.2 ppb855
City of Goldsboro*Goldsboro, NC8 of 81,007.0 ppb36,306
Wayne Water Districts PurchaseGoldsboro, NC8 of 81,007.0 ppb16,302
Fork Township PurchaseGoldsboro, NC8 of 81,007.0 ppb2,540
Seymour Johnson Air Force BaseSeymour Johnson, NC8 of 81,007.0 ppb6,875
City of WylieWylie, TX8 of 81,006.9 ppb41,043
City of Forney*Forney, TX8 of 8989.6 ppb19,122
Talty Special Utility DistrictForney, TX8 of 8989.6 ppb9,570
Kaufman County Fresh Water Supply District 1aDallas, TX8 of 8989.6 ppb6,024
Markout Water Supply CorporationForney, TX8 of 8989.6 ppb2,835
Okeechobee Utility AuthorityOkeechobee, FL12 of 12986.6 ppb20,000
Des Plaines Mobile Home ParkSanta Ana, IL4 of 4968.5 ppb340
CentralWinter Haven, FL17 of 17968.2 ppb13,595
University of Central FloridaOrlando, FL4 of 4946.5 ppb57,500
Scranton Water SystemScranton, IA2 of 2939.5 ppb557
Broward County Water and Wastewater Services (BCWWS) - 1ALauderdale Lakes, FL4 of 4935.0 ppb75,305
Saint Basils AcademyGarrison, NY4 of 4921.3 ppb130
Longacre Estates Mobile Home ParkCharleston, IL8 of 8914.6 ppb210
Charleston*Charleston, IL8 of 8914.6 ppb15,500
Eastern Illinois UniversityCharleston, IL8 of 8914.6 ppb5,500
Town of Little Elm*Little Elm, TX6 of 6897.7 ppb31,355
Windermere CommunityPflugerville, TX24 of 24896.1 ppb20,091
Poplar BluffPoplar Bluff, MO16 of 16883.4 ppb17,266
New Mexico State UniversityLas Cruces, NM10 of 10865.4 ppb24,302
Southwest/Polk County UtilityLakeland, FL20 of 20863.7 ppb39,209
Blackland Water Supply CorporationFate, TX8 of 8849.0 ppb4,872
Afton Public Works AuthorityAfton, OK8 of 8837.8 ppb1,428
City of Mesquite*Mesquite, TX8 of 8827.5 ppb143,484
Kaufman County Municipal Utility District 12*Dallas, TX8 of 8827.5 ppb0

* 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 Chlorate, but it likely has the contaminant in its water supply.

UtilityLocationTestsAverage levelPeople served
City of BonhamBonham, TX8 of 82,031.9 ppb10,123
VC/Southwest Water SystemOrange City, FL12 of 121,735.0 ppb20,725
SavageSavage, MN3 of 61,687.7 ppb26,911
Willingboro MUA*Willingboro, NJ8 of 81,379.0 ppb35,000
Pennsville Twsp. Water Depart.Pennsville, NJ7 of 81,316.4 ppb13,500
Danvers Water Department*Middleton, MA11 of 111,244.5 ppb35,480
Marshall County Water CorpMadill, OK8 of 101,161.6 ppb14,717
Houma Water Treatment Service AreaHouma, LA8 of 81,103.8 ppb31,560
Seminole County NortheastLake Mary, FL8 of 81,052.7 ppb18,462
St. MarysSt. Marys, GA5 of 61,047.7 ppb17,270
City of Terrell*Terrell, TX8 of 81,040.9 ppb24,744
Alco Water ServiceSalinas, CA6 of 71,021.7 ppb29,179
Wayne Water Districts PurchaseGoldsboro, NC8 of 81,007.0 ppb16,302
City of Goldsboro*Goldsboro, NC8 of 81,007.0 ppb36,306
City of WylieWylie, TX8 of 81,006.9 ppb41,043
City of Forney*Forney, TX8 of 8989.6 ppb19,122
Okeechobee Utility AuthorityOkeechobee, FL12 of 12986.6 ppb20,000
CentralWinter Haven, FL17 of 17968.2 ppb13,595
University of Central FloridaOrlando, FL4 of 4946.5 ppb57,500
Broward County Water and Wastewater Services (BCWWS) - 1ALauderdale Lakes, FL4 of 4935.0 ppb75,305
Charleston*Charleston, IL8 of 8914.6 ppb15,500
Town of Little Elm*Little Elm, TX6 of 6897.7 ppb31,355
Windermere CommunityPflugerville, TX24 of 24896.1 ppb20,091
Poplar BluffPoplar Bluff, MO16 of 16883.4 ppb17,266
New Mexico State UniversityLas Cruces, NM10 of 10865.4 ppb24,302
Southwest/Polk County UtilityLakeland, FL20 of 20863.7 ppb39,209
City of Mesquite*Mesquite, TX8 of 8827.5 ppb143,484
City of GarlandGarland, TX8 of 8821.5 ppb236,786
City of Frisco*Frisco, TX8 of 8817.3 ppb159,000
City of RichardsonRichardson, TX8 of 8807.8 ppb104,300
Marshall*Marshall, MO6 of 6793.7 ppb13,065
City of Edgewater*Edgewater, FL4 of 4790.5 ppb23,575
City of AlamoAlamo, TX8 of 8788.9 ppb18,363
City of MaitlandMaitland, FL12 of 12787.5 ppb13,268
City of Port St. JoePort St. Joe, FL8 of 8777.5 ppb12,806
City of AllenAllen, TX8 of 8774.4 ppb93,528
N.S. MayportMayport, FL4 of 4765.7 ppb20,500
City of Richmond*Richmond, VA8 of 8765.0 ppb197,000
City of Weston (Indian Trace)Weston, FL4 of 4759.8 ppb52,300
Lake Utility Services Inc NorthClermont, FL23 of 23757.0 ppb21,518
Wellington Water Treatment PlantWellington, FL4 of 4756.0 ppb58,265
City of Coconut CreekCoconut Creek, FL4 of 4755.0 ppb54,000
Maynard DPW, Water DivisionMaynard, MA6 of 6746.7 ppb10,314
City of McKinney*Mckinney, TX8 of 8738.8 ppb169,710
Alexander City Water Department*Alex City, AL8 of 8732.5 ppb27,000
Lee County Utilities*Fort Myers, FL26 of 26732.0 ppb236,944
City of LemooreLemoore, CA10 of 10716.0 ppb24,945
Broward County Water and Wastewater Services (BCWWS) - 2A*Pompano Beach, FL4 of 4712.5 ppb54,622
Curry Water AuthorityJasper, AL8 of 8708.8 ppb17,160
Winter Haven Water DepartmentWinter Haven, FL34 of 34700.6 ppb70,653

* 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 Chlorate, but it likely has the contaminant in its water supply.