Hexachlorocyclopentadiene
Status: National drinking water standard exists
Hexachlorocyclopentadiene was historically used for the manufacture of currently banned pesticides, such as endrin, dieldrin and chlordane. It’s still used for production of flame retardants, resins and plastics.
2017-2019:
24
states detected
241
utilities detected
5.9 million
people served
0
states over health guideline
0
utilities over health guideline
0
people served over health guideline
0
states over legal limit
0
utilities over legal limit
0
people served over legal limit
Health concerns for hexachlorocyclopentadiene
Harm to the stomach and intestines
Change to the liver
Change to the kidney
Irritation of the lungs
State and national drinking water standards and health guidelines
EWG Health Guideline 2 ppb
The EWG Health Guideline of 2 ppb for hexachlorocyclopentadiene 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 the stomach and intestines.
EPA Maximum Contaminant
Level (MCL) 50 ppb
The legal limit for hexachlorocyclopentadiene, established in 1992, was based on a toxicity study in laboratory animals conducted in the 1980s.
ppb = parts per billion
States reporting hexachlorocyclopentadiene in drinking water
UTILITIES WITH CONTAMINATION | |||
---|---|---|---|
State | Utilities | People Served | |
Missouri | 7 | 1,210,240 | |
Oregon | 9 | 699,062 | |
New York | 17 | 680,004 | |
Louisiana | 28 | 675,329 | |
Colorado | 27 | 654,019 | |
Florida | 44 | 480,934 | |
Nevada | 4 | 393,732 | |
Pennsylvania | 8 | 236,160 | |
Texas | 12 | 173,505 | |
Indiana | 14 | 162,206 | |
Massachusetts | 4 | 107,542 | |
Kentucky | 9 | 89,474 | |
North Carolina | 17 | 82,703 | |
Wisconsin | 6 | 80,685 | |
New Mexico | 16 | 44,959 | |
Oklahoma | 6 | 35,071 | |
Hawaii | 1 | 29,868 | |
Maryland | 2 | 12,000 | |
Arkansas | 2 | 4,828 | |
West Virginia | 2 | 1,267 | |
Vermont | 2 | 936 | |
Alaska | 1 | 225 | |
Arizona | 1 | 150 | |
Delaware | 2 | 109 |
Filtering technologies that reduce hexachlorocyclopentadiene

Activated Carbon

Reverse Osmosis
Utilities with the highest amounts of hexachlorocyclopentadiene, 2017-2019
Utility | Location | Tests | Average level | People served |
---|---|---|---|---|
City of Pocomoke City | Pocomoke City, MD | 1 of 1 | 0.830 ppb | 4,100 |
Vallenar View Mobile Home Park | Ketchikan, AK | 4 of 5 | 0.200 ppb | 225 |
Osage County Rural Water District # 20 (hulah) | Bartlesville, OK | 1 of 1 | 0.140 ppb | 350 |
Lumberton Mutual Domestic Water Consumers Association | Lumberton, NM | 2 of 2 | 0.130 ppb | 223 |
Mcindoe Falls Fire District 3 | Mcindoe Falls, VT | 7 of 11 | 0.119 ppb | 176 |
West Hammond Mutual Domestic Water Consumers Association | Bloomfield, NM | 4 of 4 | 0.118 ppb | 3,739 |
Lee Acres Water Users Association | Farmington, NM | 4 of 4 | 0.118 ppb | 5,078 |
Lee/hammond Water Treatment Plant Co-op* | Farmington, NM | 4 of 4 | 0.118 ppb | 0 |
Apple Orchard Mdwca | Bloomfield, NM | 12 of 12 | 0.109 ppb | 460 |
Bloomfield Water Supply System* | Bloomfield, NM | 12 of 12 | 0.109 ppb | 7,090 |
Blanco Mutual Domestic Water Consumers Association | Blanco, NM | 12 of 12 | 0.109 ppb | 1,140 |
Navajo Dam Domestic Water Consumers Inc. | Navajo Dam, NM | 3 of 3 | 0.104 ppb | 538 |
Upper La Plata Water Users Association | La Plata, NM | 2 of 2 | 0.0855 ppb | 2,265 |
Willsboro Water District | Willsboro, NY | 1 of 2 | 0.0855 ppb | 1,571 |
Lower Valley Water Users Association* | Kirtland, NM | 2 of 2 | 0.0855 ppb | 8,647 |
City of Rose City | Vidor, TX | 2 of 6 | 0.0800 ppb | 550 |
Pine River Mdca | Ignacio, NM | 1 of 1 | 0.0800 ppb | 44 |
City of Evanston* | Evanston, WY | 2 of 3 | 0.0767 ppb | 12,000 |
Bear River Regional Joint Powers | Bear River, WY | 2 of 3 | 0.0767 ppb | 1,200 |
Harlem, City of | Harlem, MT | 2 of 4 | 0.0700 ppb | 820 |
Valley View Center For Nursing Care & Rehab | Goshen, NY | 8 of 21 | 0.0667 ppb | 850 |
O.c. Correctional Facility | Goshen, NY | 8 of 21 | 0.0667 ppb | 750 |
Hearthstone Manor | Chapaqua, NY | 8 of 21 | 0.0667 ppb | 110 |
Florida Village* | Florida, NY | 8 of 21 | 0.0667 ppb | 4,585 |
Bard College | , NY | 1 of 2 | 0.0650 ppb | 1,400 |
South Hero Fire District 4 | South Hero, VT | 9 of 23 | 0.0626 ppb | 760 |
Crested Butte, Town of | Crested Butte, CO | 3 of 8 | 0.0625 ppb | 2,452 |
Beaver Valley Water Company | Payson, AZ | 2 of 7 | 0.0571 ppb | 150 |
Newport Ridge Mobile Home Park | Newport, NC | 4 of 11 | 0.0527 ppb | 71 |
Sopris Village Homeowners Association | Carbondale, CO | 1 of 6 | 0.0517 ppb | 425 |
Carthage, Town of | Carthage, NC | 2 of 7 | 0.0509 ppb | 4,216 |
St. Lucie Mobile Village | Indiantown, FL | 1 of 2 | 0.0500 ppb | 750 |
Kemmerer-diamondville Jpb | Kemmerer, WY | 3 of 6 | 0.0500 ppb | 3,367 |
Camelot III | Derry, NH | 1 of 9 | 0.0467 ppb | 30 |
City of Nome | Nome, TX | 2 of 9 | 0.0433 ppb | 602 |
Newport Municipal Utility District | Houston, TX | 4 of 12 | 0.0425 ppb | 10,374 |
West Wise Special Utility District* | Bridgeport, TX | 1 of 9 | 0.0411 ppb | 3,354 |
Oak Creek, Town of | Oak Creek, CO | 1 of 2 | 0.0400 ppb | 950 |
Swanton Village Water | Swanton, VT | 1 of 5 | 0.0400 ppb | 2,986 |
Coweta | Coweta, OK | 1 of 1 | 0.0400 ppb | 9,450 |
Naval Base Kitsap At Bremerton | Bremerton, WA | 2 of 2 | 0.0400 ppb | 2,078 |
Rocky Point Water District 12 | Bremerton, WA | 2 of 2 | 0.0400 ppb | 1,777 |
Jackson Park Naval Hospital | Bremerton, WA | 2 of 2 | 0.0400 ppb | 1,121 |
City of Bremerton* | Bremerton, WA | 2 of 2 | 0.0400 ppb | 56,565 |
Holiday Estates | Millsboro, DE | 2 of 2 | 0.0395 ppb | 37 |
Wisconsin Rapids Water Works & Lighting Comm. | Wisconsin Rapids, WI | 1 of 1 | 0.0390 ppb | 20,000 |
City of Paradise | Paradise, TX | 1 of 6 | 0.0383 ppb | 459 |
Walnut Creek SUD* | Springtown, TX | 1 of 6 | 0.0383 ppb | 23,118 |
City of Port Neches | Port Neches, TX | 3 of 9 | 0.0367 ppb | 13,040 |
Oneonta City | Oneonta, NY | 1 of 5 | 0.0360 ppb | 15,779 |
* 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 Hexachlorocyclopentadiene, but it likely has the contaminant in its water supply.
Utility | Location | Tests | Average level | People served |
---|---|---|---|---|
City of Evanston* | Evanston, WY | 2 of 3 | 0.0767 ppb | 12,000 |
Newport Municipal Utility District | Houston, TX | 4 of 12 | 0.0425 ppb | 10,374 |
City of Bremerton* | Bremerton, WA | 2 of 2 | 0.0400 ppb | 56,565 |
Wisconsin Rapids Water Works & Lighting Comm. | Wisconsin Rapids, WI | 1 of 1 | 0.0390 ppb | 20,000 |
Walnut Creek SUD* | Springtown, TX | 1 of 6 | 0.0383 ppb | 23,118 |
City of Port Neches | Port Neches, TX | 3 of 9 | 0.0367 ppb | 13,040 |
Oneonta City | Oneonta, NY | 1 of 5 | 0.0360 ppb | 15,779 |
Craven County Water System* | New Bern, NC | 1 of 34 | 0.0344 ppb | 32,500 |
City of Albemarle* | Albemarle, NC | 2 of 23 | 0.0339 ppb | 17,874 |
Holyoke Water Works | Holyoke, MA | 2 of 6 | 0.0315 ppb | 40,124 |
City of Montrose* | Montrose, CO | 4 of 9 | 0.0309 ppb | 19,305 |
Tri County WCD | Montrose, CO | 4 of 9 | 0.0309 ppb | 18,200 |
Lebanon Water Authority* | Lebanon, PA | 1 of 9 | 0.0289 ppb | 57,000 |
City of Great Falls* | Great Falls, MT | 2 of 8 | 0.0288 ppb | 60,000 |
Prestonsburg City Utilities* | Prestonsburg, KY | 1 of 4 | 0.0275 ppb | 20,368 |
Town of Estes Park* | Estes Park, CO | 4 of 13 | 0.0272 ppb | 16,722 |
Gretna Waterworks | Gretna, LA | 14 of 22 | 0.0263 ppb | 17,802 |
United Water Pa Mechanicsburg | Harrisburg, PA | 1 of 12 | 0.0250 ppb | 32,336 |
White Plains City* | White Plains, NY | 1 of 6 | 0.0250 ppb | 59,353 |
Southern Pines* | Pinebluff, NC | 2 of 11 | 0.0240 ppb | 21,121 |
North Tonawanda City | North Tonawanda, NY | 1 of 4 | 0.0238 ppb | 31,568 |
Ellettsville Water Works | Ellettsville, IN | 6 of 26 | 0.0231 ppb | 12,800 |
City of Bloomington Utilities* | Bloomington, IN | 6 of 26 | 0.0231 ppb | 83,000 |
Upper Eagle Regional WA* | Vail, CO | 10 of 37 | 0.0227 ppb | 31,581 |
Grayson Utility Commission* | Grayson, KY | 1 of 4 | 0.0203 ppb | 10,950 |
Sheboygan Water Utilities* | Sheboygan, WI | 1 of 1 | 0.0200 ppb | 49,288 |
Harris County FWSD 51* | Houston, TX | 1 of 12 | 0.0192 ppb | 10,401 |
Amherst DPW Water Division | Amherst, MA | 1 of 6 | 0.0177 ppb | 37,819 |
Greenup Water System* | Greenup, KY | 1 of 5 | 0.0174 ppb | 12,193 |
Lower Bucks County Joint Municipal Authority* | Levittown, PA | 1 of 11 | 0.0173 ppb | 63,007 |
Havelock Water System* | Havelock, NC | 1 of 9 | 0.0167 ppb | 14,246 |
Westchester County Water District #1* | New Rochelle, NY | 1 of 10 | 0.0150 ppb | 340,839 |
Lakeshore Swartz Water System | West Monroe, LA | 6 of 24 | 0.0143 ppb | 11,330 |
Monroe Water System* | Monroe, LA | 6 of 24 | 0.0143 ppb | 52,572 |
North Monroe Et Al Water System | West Monroe, LA | 6 of 24 | 0.0143 ppb | 10,866 |
Fredonia Village* | Fredonia, NY | 1 of 4 | 0.0138 ppb | 10,984 |
Scarsdale Water Department | Scarsdale, NY | 1 of 11 | 0.0136 ppb | 20,608 |
City of Frederick* | Frederick, MD | 2 of 40 | 0.0133 ppb | 54,000 |
Bedford City Utilities* | Bedford, IN | 3 of 23 | 0.0130 ppb | 14,000 |
Aqua Pa Bristol* | Bryn Mawr, PA | 1 of 17 | 0.0129 ppb | 28,728 |
City of League City | League City, TX | 3 of 27 | 0.0126 ppb | 104,857 |
Yonkers City | Yonkers, NY | 1 of 13 | 0.0115 ppb | 196,086 |
Neenah Waterworks | Neenah, WI | 1 of 4 | 0.0115 ppb | 25,892 |
Assumption Parish Waterworks District 1* | Napoleonville, LA | 6 of 24 | 0.0114 ppb | 22,862 |
Belle Chasse Water District | Belle Chasse, LA | 8 of 22 | 0.0111 ppb | 17,391 |
Superior Water Light & Power Company | Superior, WI | 1 of 4 | 0.0110 ppb | 29,571 |
Fort Carson Army Base | Fort Carson, CO | 8 of 40 | 0.0109 ppb | 42,000 |
US Air Force Academy | Usaf Academy, CO | 8 of 40 | 0.0109 ppb | 16,876 |
Colorado Springs Utilities* | Colorado Springs, CO | 8 of 40 | 0.0109 ppb | 450,461 |
Walpole Water Department | Walpole, MA | 1 of 14 | 0.0107 ppb | 23,989 |
* 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 Hexachlorocyclopentadiene, but it likely has the contaminant in its water supply.