EWG's Tap Water Database — 2021 UPDATE



Status: National drinking water standard exists


2,4-D (2,4-dichlorophenoxyacetic acid) is a herbicide that can be applied directly to GMO corn and soy plants engineered to withstand this toxic chemical. Americans' exposures to 2,4-D from food and drinking water will likely increase in years to come as farmers plant more of these GMO crops. Read More.

2,4-D is an endocrine disruptor that interferes with thyroid hormones. The International Agency for Research on Cancer classifies 2,4-D as possibly carcinogenic to humans. In occupational studies, farmers exposed to 2,4-D tended to have higher incidences of damaged and malformed sperm. Laboratory animals exposed to 2,4-D during gestation are born underdeveloped and are more likely to have birth defects.




states detected


utilities detected

16 million

people served


states over health guideline


utilities over health guideline


people served over health guideline

Health concerns for 2,4-D

Hormone disruption

Harm to the liver

Harm to the kidney

Harm to the thyroid

Harm to the brain and nervous system

Change to immune system function

State and national drinking water standards and health guidelines

EWG Health Guideline 20 ppb

The EWG Health Guideline of 20 ppb for 2,4-D 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 harm to internal organs.

EPA Maximum Contaminant
Level (MCL) 70 ppb

The legal limit for 2,4-D, established in 1991, was based on toxicity studies in laboratory animals conducted in the 1980s. This limit may not fully protect against harm to the nervous system, harm to the thyroid, and hormone disruption.

ppb = parts per billion

States reporting 2,4-D in drinking water

State UtilitiesPeople Served
New York31100,492
West Virginia1067,876
South Carolina361,705
North Carolina229,151
North Dakota21,976
New Mexico1200

Filtering technologies that reduce 2,4-D

carbon filter icon

Activated Carbon

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Reverse Osmosis

Utilities with the highest amounts of 2,4-D, 2017-2019

UtilityLocationTestsAverage levelPeople served
Woods Hoa, TheMartinsburg, WV1 of 32.87 ppb1,550
Elk Creek, Village ofElk Creek, NE2 of 22.40 ppb95
Sidney City PWSSidney, OH1 of 61.35 ppb21,229
Live Oak WTPLive Oak, FL1 of 80.969 ppb6,850
Valley Water and Sewer-deerwoodKearneysville, WV1 of 20.915 ppb219
CoultervilleCoulterville, IL2 of 110.591 ppb985
St Charles Co. PWSD #2 Wright CityWright City, MO1 of 50.496 ppb3,550
LaharpeLaharpe, IL1 of 120.467 ppb1,235
Oak Meadows Subdivision Water SystemLake Charles, LA4 of 100.440 ppb318
Texas Water SupplyLivingston, TX1 of 20.400 ppb174
Smith Mobile Home Village Water SystemNewark, LA4 of 120.367 ppb200
Thomas City OfThomas, WV1 of 30.363 ppb725
City of Martinsburg*Martinsburg, WV1 of 80.350 ppb15,652
Toledo Village Water Supply CorporationJasper, TX3 of 80.325 ppb1,624
Hoyleton-new Minden*Hoyleton, IL1 of 90.322 ppb48
Nashville*Nashville, IL1 of 90.322 ppb4,068
Peak View RanchApache Junction, AZ1 of 10.320 ppb232
Beardsley Water Company 1Phoenix, AZ2 of 20.320 ppb1,471
Taylor Coastal Water & Sewer DistrictPerry, FL1 of 70.284 ppb1,303
Water Unlimited, Incorporated*Newcastle, WY1 of 40.275 ppb80
North Castle Water District #7Armonk, NY1 of 110.275 ppb100
North Castle Water District #4*Armonk, NY1 of 110.275 ppb2,525
North Castle Water District #5Armonk, NY1 of 110.275 ppb225
Village of Calvin Water SystemCalvin, LA2 of 120.273 ppb591
Clear Creek Forest Section 12Austin, TX2 of 80.250 ppb1,779
Frostproof, City ofFrostproof, FL2 of 120.250 ppb3,550
Breezy Hill WDGraniteville, SC3 of 390.244 ppb15,282
Northwest Freeway Municipal Utility DistrictHouston, TX2 of 80.238 ppb3,558
Chain Ridge SubdivisionSolon, IA1 of 30.233 ppb25
Aqua Pa OakhillWhite Haven, PA1 of 80.225 ppb486
Southshore WaterMeridian, ID1 of 40.215 ppb30
EvansvilleEvansville, IL1 of 70.171 ppb700
Pomfret Berry Road Water DistrictFredonia, NY1 of 40.168 ppb160
Essex Water DistrictEssex, NY1 of 20.168 ppb350
Pomfret Chestnut Road Water DistrictFredonia, NY1 of 40.168 ppb64
Pomfret North End Water DistrictFredonia, NY1 of 40.168 ppb360
Fredonia Village*Fredonia, NY1 of 40.168 ppb10,984
Far Horizons SubdivisionSwisher, IA1 of 50.160 ppb80
Pinewood Springs Water DistrictLyons, CO2 of 170.159 ppb745
Elbert Creek Water Co.Durango, CO1 of 20.150 ppb525
Lafourche Water District 1Lockport, LA10 of 460.149 ppb78,760
Langdon, City ofLangdon, ND2 of 30.142 ppb1,878
Apple Creek Water Co-opWaverly, IL1 of 120.142 ppb949
Waverly*Waverly, IL1 of 120.142 ppb1,307
LenzburgBelleville, IL1 of 100.140 ppb620
Kaskaskia Water District*New Athens, IL1 of 100.140 ppb1
MarissaFreeburg, IL1 of 100.140 ppb2,200
New AthensNew Athens, IL1 of 100.140 ppb2,225
TildenTilden, IL1 of 100.140 ppb934
GreenfieldGreenfield, IL1 of 80.138 ppb1,200

* 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 2,4-D, but it likely has the contaminant in its water supply.

UtilityLocationTestsAverage levelPeople served
Sidney City PWSSidney, OH1 of 61.35 ppb21,229
City of Martinsburg*Martinsburg, WV1 of 80.350 ppb15,652
Breezy Hill WDGraniteville, SC3 of 390.244 ppb15,282
Fredonia Village*Fredonia, NY1 of 40.168 ppb10,984
Lafourche Water District 1Lockport, LA10 of 460.149 ppb78,760
Spring Hill Water Department*Spring Hill, TN1 of 30.133 ppb45,130
RosevilleRoseville, MN2 of 50.120 ppb36,314
Saint Paul Regional Water Services*St. Paul, MN2 of 50.120 ppb395,131
City of Cullman Water Works*Cullman, AL2 of 40.1000 ppb35,922
Rockwood Water System*Rockwood, TN1 of 20.1000 ppb11,594
City of FriendswoodFriendswood, TX2 of 100.1000 ppb37,921
New Haven Water DepartmentNew Haven, IN6 of 250.0840 ppb15,700
Fort Wayne - 3 Rivers Filtration Plant*Fort Wayne, IN6 of 250.0840 ppb266,000
Bedford City Utilities*Bedford, IN1 of 40.0750 ppb14,000
CentralWinter Haven, FL1 of 200.0750 ppb13,595
Holyoke Water WorksHolyoke, MA1 of 60.0732 ppb40,124
Miramar (East & West) PlantsMiramar, FL2 of 230.0731 ppb127,700
Port Washington WDPort Washington, NY1 of 360.0722 ppb34,000
Portland Water SystemPortland, TN2 of 70.0714 ppb21,516
Holliston Water DepartmentHolliston, MA4 of 220.0670 ppb14,946
Indiana American Water - MuncieGreenwood, IN2 of 30.0667 ppb65,618
City of Port St. JoePort St. Joe, FL3 of 90.0656 ppb13,836
Elk RiverElk River, MN1 of 40.0625 ppb16,914
Cleveland Utilities*Cleveland, TN1 of 80.0625 ppb87,960
Citizens Water - Indianapolis*Indianapolis, IN9 of 760.0583 ppb825,173
Tri-County Water Distbr District*Russelville, AR1 of 80.0538 ppb16,671
City of Taylor*Taylor, TX1 of 20.0500 ppb18,252
Consolidated Mutual Maple Grove*Lakewood, CO1 of 40.0473 ppb24,135
Aqua Pennsylvania Main System*Bryn Mawr, PA1 of 320.0469 ppb747,460
Philadelphia Water Department*Philadelphia, PA2 of 280.0464 ppb1,600,000
Clinton, City of*Clinton, SC2 of 140.0443 ppb10,109
Missouri American Jefferson City DistrictJefferson City, MO3 of 120.0417 ppb27,117
Texarkana Water Utilities*Texarkana, AR1 of 70.0414 ppb30,015
Thibodaux WaterworksThibodaux, LA2 of 220.0409 ppb15,810
Chester Metro*Chester, SC1 of 180.0394 ppb12,719
Amsterdam*Amsterdam, NY1 of 60.0393 ppb22,132
City of CleburneCleburne, TX3 of 260.0380 ppb30,573
Johnstown Water Works*Johnstown, NY1 of 100.0353 ppb10,851
Jefferson County PWSD 3*Arnold, MO11 of 650.0338 ppb17,000
Missouri American St. Louis County & St. Charles County*Chesterfield, MO11 of 650.0338 ppb1,100,000
Jefferson County PWSD1*Arnold, MO11 of 650.0338 ppb20,000
KirkwoodKirkwood, MO11 of 650.0338 ppb28,000
Jefferson County PWSD 10Arnonld, MO11 of 650.0338 ppb10,000
Jefferson County Cons. PWSD C 1*Barnhart, MO11 of 650.0338 ppb35,000
Murphysboro*Murphysboro, IL3 of 150.0333 ppb10,941
Winchester Water SystemWinchester, TN1 of 90.0333 ppb20,180
Evansville Water Utility*Evansville, IN3 of 230.0304 ppb173,000
German Township Water District Inc.*Evansville, IN3 of 230.0304 ppb12,110
Glens Falls CityGlens Falls, NY1 of 130.0292 ppb14,000
Hardin County Water District #2Elizabethtown, KY1 of 70.0286 ppb76,326

* 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 2,4-D, but it likely has the contaminant in its water supply.