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EWG's Tap Water Database — 2019 UPDATE

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Diquat

Status: National drinking water standard exists

 

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

2015-2017:

FOUND
FOUND ABOVE HEALTH GUIDELINES

7

states detected

55

utilities detected

2.2 million

people served

0

states over health guideline

0

utilities over health guideline

0

people served over health guideline

Health concerns for diquat

Change to fetal growth and development

Change in body weight

Harm to the kidney

Cataracts

State and national drinking water standards and health guidelines

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

States reporting diquat in drinking water

UTILITIES WITH CONTAMINATION
State UtilitiesPeople Served
Texas291,224,714
Florida14638,365
Nevada3280,700
Louisiana330,615
Arizona118,900
Oklahoma22,505
Wyoming32,030
MORE
LESS

Filtering technologies that reduce diquat

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Utilities with the highest amounts of diquat, 2015-2017

ALL UTILITIES
LARGE UTILITIES
UtilityLocationTestsAverage levelPeople served
Frostproof, City ofFrostproof, FL2 of 62.53 ppb3,550
High Valley Water Supply CorporationAustin, TX2 of 51.000 ppb231
City of Sunset ValleySunset Valley, TX2 of 51.000 ppb1,473
City of RollingwoodRollingwood, TX2 of 51.000 ppb1,596
Rivercrest Water System*Austin, TX2 of 51.000 ppb1,437
City of Austin Water & Wastewater*Austin, TX2 of 51.000 ppb981,783
Travis County Water Control and Improvement District 10West Lake Hills, TX2 of 51.000 ppb8,913
Nighthawk Water Supply CorporationAustin, TX2 of 51.000 ppb396
North Austin Municipal Utility District 1Austin, TX2 of 51.000 ppb11,133
Wells Branch MUD 1Austin, TX2 of 51.000 ppb21,129
Hill Oaks Mobile EstatesAustin, TX2 of 51.000 ppb168
Northtown MUDAustin, TX2 of 51.000 ppb11,520
Marsha Water Supply CorporationAustin, TX2 of 51.000 ppb480
Mid-tex UtilitiesPflugerville, TX2 of 51.000 ppb945
Start Water SystemStart, LA2 of 40.950 ppb2,514
CentralWinter Haven, FL1 of 100.760 ppb13,595
FletcherFletcher, OK2 of 30.467 ppb1,022
City of Lakeside CityWichita Falls, TX3 of 50.360 ppb1,100
Horseshoe Bend EstatesIowa Park, TX3 of 50.360 ppb100
City of Wichita Falls*Wichita Falls, TX3 of 50.360 ppb103,000
City of Iowa Park*Iowa Park, TX3 of 50.360 ppb6,355
Friberg-cooper Water Supply CorporationWichita Falls, TX3 of 50.360 ppb918
Town of Pleasant ValleyIowa Park, TX3 of 50.360 ppb330
Archer County Municipal Utility District 1Wichita Falls, TX3 of 50.360 ppb1,221
City of ScotlandScotland, TX3 of 50.360 ppb850
City of HollidayHolliday, TX3 of 50.360 ppb1,758
Sheppard Air Force BaseSheppard Afb, TX3 of 50.360 ppb19,500
Superior, Town OfSuperior, WY1 of 40.308 ppb250
Antelope ValleyGillette, WY1 of 30.280 ppb1,280
Whispering Pines Mobile Home ParkFrostproof, FL1 of 20.220 ppb215
Windermere CommunityPflugerville, TX5 of 180.217 ppb20,091
Ely Municipal Water Department*Ely, NV1 of 120.192 ppb5,000
Ruth Water DistrictMcgill, NV1 of 120.192 ppb700
Intracoastal Water System WestPlaquemine, LA2 of 160.138 ppb6,501
Crestview Estates SubdivisionGillette, WY1 of 30.137 ppb500
Mulberry, City ofMulberry, FL2 of 50.120 ppb3,780
South Broward Utility/sunriseFort Lauderdale, FL1 of 30.1000 ppb9,457
Fern Crest Utilities Inc.Ft Lauderdale, FL1 of 30.1000 ppb4,643
Manatee County Utilities Department*Bradenton, FL1 of 100.0970 ppb447,382
Heather Hills EstatesBradenton, FL1 of 100.0970 ppb700
Palmetto Water DepartmentPalmetto, FL1 of 100.0970 ppb12,606
Town of Longboat KeyLongboat Key, FL1 of 100.0970 ppb7,603
Sunny Shore Water CompanyBradenton, FL1 of 100.0970 ppb450
Harbour Isles Master AssociationBradenton, FL1 of 100.0970 ppb200
Boise City Public Works AuthorityBoise City, OK1 of 120.0833 ppb1,483
Beauregard Water Works District #3Longville, LA2 of 220.0782 ppb21,600
City of HendersonLas Vegas, NV1 of 70.0686 ppb275,000
Miramar (East & West) PlantsMiramar, FL1 of 60.0500 ppb128,729
City of Fort MeadeFort Meade, FL1 of 20.0500 ppb5,455
City of SaffordThatcher, AZ1 of 160.0350 ppb18,900

* 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
City of Austin Water & Wastewater*Austin, TX2 of 51.000 ppb981,783
Northtown MUDAustin, TX2 of 51.000 ppb11,520
Wells Branch MUD 1Austin, TX2 of 51.000 ppb21,129
North Austin Municipal Utility District 1Austin, TX2 of 51.000 ppb11,133
CentralWinter Haven, FL1 of 100.760 ppb13,595
City of Wichita Falls*Wichita Falls, TX3 of 50.360 ppb103,000
Sheppard Air Force BaseSheppard Afb, TX3 of 50.360 ppb19,500
Windermere CommunityPflugerville, TX5 of 180.217 ppb20,091
Manatee County Utilities Department*Bradenton, FL1 of 100.0970 ppb447,382
Palmetto Water DepartmentPalmetto, FL1 of 100.0970 ppb12,606
Beauregard Water Works District #3Longville, LA2 of 220.0782 ppb21,600
City of HendersonLas Vegas, NV1 of 70.0686 ppb275,000
Miramar (East & West) PlantsMiramar, FL1 of 60.0500 ppb128,729
City of SaffordThatcher, AZ1 of 160.0350 ppb18,900

* 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.