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CONTAMINANT

Diquat

FOUND

Exceeding guidelines

STATES DETECTED

15

serves

1.4 million

utilities detected

69

states detected

1

serves

0

utilities detected

1

Overview

Diquat is a herbicide used on potato crops and aquatic weeds.

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 6 ppb

The EWG Health Guideline of 6 ppb for diquat 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 cataracts.

EPA Maximum Contaminant
Level (MCL): 20 ppb

The legal limit for diquat, established in 1992, was based on a toxicity study in laboratory animals conducted in the 1980s.

ppb = parts per billion

National Standard Exists

Health Concerns:

  • Change to fetal growth and development

  • Change in body weight

  • Harm to the kidney

  • Cataracts

Want to remove
Diquat from your water?

Try these filter technologies:

Activated Carbon, 

Reverse Osmosis, 

understand filter technology

Diquat around the Country

UTILITIES REPORTING ABOVE HEALTH GUIDELINES UTILITIES WITH CONTAMINATION
State Utilities People Served Utilities People Served
Texas00151,202,413
Louisiana00885,007
Florida002358,900
California10941,033
Kentucky00311,034
Maine0025,930
Massachusetts0014,338
Indiana0014,075
Alabama0013,825
Oklahoma001300
Pennsylvania001280
New Mexico001253
Oregon001130
Ohio00151
Arkansas00134

Utilities with the highest amounts of diquat, 2021-2023

ALL UTILITIES
LARGE UTILITIES
Utility Location Tests Average level People served
Water Facilities Authority-jpa*Upland, CA1 of 118.0 ppb0
Barrett Lake Mobile Home and Rv LLCSantee, CA1 of 14.40 ppb150
Crestwood Mobile Home ParkMountain Home, AR1 of 72.14 ppb34
Corinth Water DistrictCorinth, KY1 of 60.722 ppb3,139
Williamstown Municipal Water Department*Dry Ridge, KY1 of 60.722 ppb5,495
Dry Ridge Water Works CommissionDry Ridge, KY1 of 60.722 ppb2,400
Alpine Village W and SDRuidoso, NM1 of 20.600 ppb253
Ranch Oaks EstatesThonotosassa, FL1 of 70.429 ppb148
Briarwood EstatesKathleen, FL2 of 90.422 ppb80
Villa MargaretOkeechobee, FL1 of 10.400 ppb132
Indian River Shores Mobile Home ParkMicco, FL1 of 10.400 ppb55
Soundings Yacht & Tennis ClubHobe Sound, FL1 of 10.400 ppb450
Hillcrest Estates, Inc.Zephyrhills, FL1 of 10.380 ppb130
Northport Village Corporation Water DepartmentWest Gardiner, ME1 of 40.375 ppb835
Belfast Water District*Belfast, ME1 of 40.375 ppb5,095
West Terre Haute WaterWest Terre Haute, IN1 of 30.333 ppb4,075
Loma Mar MutualLoma Mar, CA1 of 10.330 ppb65
Dawsons Mobile Home Park Public Water SystemPiketon, OH1 of 10.300 ppb51
Crestline Village County Water District - Division 10Crestline, CA1 of 150.267 ppb10,030
Nell-kay Mobile Home ParkRuskin, FL1 of 50.260 ppb39
Northtown MUDAustin, TX1 of 30.200 ppb11,520
Mid-tex UtilitiesPflugerville, TX1 of 30.200 ppb1,542
City of Austin Water & Wastewater*Austin, TX1 of 30.200 ppb1,115,323
City of Sunset ValleySunset Valley, TX1 of 30.200 ppb1,485
City of RollingwoodRollingwood, TX1 of 30.200 ppb1,611
Village of San LeannaManchaca, TX1 of 30.200 ppb522
Marsha Water Supply CorporationAustin, TX1 of 30.200 ppb480
Rivercrest Water System*Austin, TX1 of 30.200 ppb1,437
High Valley Water Supply CorporationAustin, TX1 of 30.200 ppb231
Travis County Water Control and Improvement District 10West Lake Hills, TX1 of 30.200 ppb9,171
Shady Hollow Municipal Utility DistrictAustin, TX1 of 30.200 ppb4,269
Wells Branch MUD 1Austin, TX1 of 30.200 ppb22,062
North Austin Municipal Utility District 1Austin, TX1 of 30.200 ppb11,133
Nighthawk Water Supply CorporationAustin, TX1 of 30.200 ppb396
Fulton Water CompanyCarnelian Bay, CA1 of 10.190 ppb2,593
Oak Park Trailer Court LLCTitusville, FL1 of 10.160 ppb90
Windermere CommunityPflugerville, TX3 of 120.142 ppb21,231
Newberg-springs, City ofNewberg, OR1 of 80.136 ppb130
Upton DPW Water/wastewater DivisionUpton, MA1 of 30.135 ppb4,338
N.A.S. JacksonvilleJacksonville, FL1 of 30.123 ppb22,000
Ashley FarmsOcala, FL2 of 190.123 ppb3,473
Baker C.i.Sanderson, FL1 of 50.121 ppb1,500
Grove Shores Mobile Home CommunityWinter Haven, FL1 of 60.120 ppb100
City of MaitlandMaitland, FL1 of 90.111 ppb13,370
Tower Manor Mobile Home CommunityAuburndale, FL1 of 50.108 ppb310
Tropical Harbor EstatesLake Placid, FL1 of 20.105 ppb650
Town Of AstatulaAstatula, FL1 of 40.1000 ppb1,937
City of BiggsBiggs, CA1 of 20.1000 ppb2,060
Okaloosa Correctional InstitutionCrestview, FL1 of 70.0819 ppb1,800
Lemoyne Water System Inc.Axis, AL1 of 110.0800 ppb3,825

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

UtilityLocationTestsAverage levelPeople served
Crestline Village County Water District - Division 10Crestline, CA1 of 150.267 ppb10,030
City of Austin Water & Wastewater*Austin, TX1 of 30.200 ppb1,115,323
North Austin Municipal Utility District 1Austin, TX1 of 30.200 ppb11,133
Wells Branch MUD 1Austin, TX1 of 30.200 ppb22,062
Northtown MUDAustin, TX1 of 30.200 ppb11,520
Windermere CommunityPflugerville, TX3 of 120.142 ppb21,231
N.A.S. JacksonvilleJacksonville, FL1 of 30.123 ppb22,000
City of MaitlandMaitland, FL1 of 90.111 ppb13,370
Sunrise SouthwestFort Lauderdale, FL1 of 40.0400 ppb10,750
City Of DixonDixon, CA1 of 80.0250 ppb11,784
Cecilia Water CorporationCecilia, LA1 of 100.0200 ppb11,949
City of Alexandria Water System*Alexandria, LA1 of 520.00500 ppb66,798

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

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