Perchlorate
Status: No national drinking water standard exists
Perchlorate, a component of rocket fuel, occurs both naturally and as a synthetic chemical. Ingested perchlorate interferes with thyroid function. Exposure to perchlorate during pregnancy and childhood can impair cognitive development. Read More.
According to the EPA, perchlorate likely contaminates the water of more than 16 million Americans. Perchlorate interferes with iodine uptake in the thyroid, which can result in reduced thyroid hormones and an impact on metabolism, physical development and cognitive development. Children and developing fetuses are the most at risk from perchlorate contamination.
Perchlorate is the only unregulated contaminant for which the EPA has attempted to set a federal drinking water standard since 1996. However, the agency has yet to propose a draft limit for this contaminant. Perchlorate in drinking water is regulated in Arizona, California, Massachusetts, New Jersey, New York and Texas. California set a public health goal of 1 part per billion for perchlorate in 2015.
2015:
4
states detected
206
utilities detected
8.3 million
people served
3
states over health guideline
39
utilities over health guideline
924,000
people served over health guideline
Health concerns for perchlorate
Hormone disruption
Harm to fetal growth and child development
State and national drinking water standards and health guidelines
Health Guideline 1 ppb
The health guideline of 1 ppb for perchlorate 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 hormone disruption.
ppb = parts per billion.
States reporting perchlorate in drinking water
| UTILITIES REPORTING ABOVE HEALTH GUIDELINES | UTILITIES WITH CONTAMINATION | ||||||
|---|---|---|---|---|---|---|---|
| State | Utilities | People Served | Utilities | People Served | |||
| California | 21 | 363,028 | 44 | 2,425,308 | |||
| Massachusetts | 2 | 4,617 | 129 | 2,037,267 | |||
| New York | 16 | 556,670 | 28 | 1,964,291 | |||
| Virginia | 0 | 0 | 2 | 1,269,000 | |||
| District Of Columbia | 0 | 0 | 3 | 644,822 | |||
Utilities with the highest amounts of perchlorate, 2015
| Utility | Location | Tests | Average level | People served |
|---|---|---|---|---|
| Locust Valley Water District | Locust Valley, NY | 2 of 2 | 8.55 ppb | 7,500 |
| Riverhead WD* | Riverhead, NY | 1 of 1 | 6.75 ppb | 37,050 |
| La Verne WD | La Verne, CA | 57 of 73 | 5.85 ppb | 32,230 |
| Marygold Mutual Water Company | Bloomington, CA | 2 of 2 | 4.90 ppb | 3,449 |
| Castaic Lake Water Agency* | Santa Clarita, CA | 231 of 865 | 4.64 ppb | 0 |
| Fairview Water Company LLC | Tehachapi, CA | 10 of 18 | 3.79 ppb | 240 |
| Tierra Buena Mobile Home Park #1 | Marysville, CA | 3 of 4 | 3.58 ppb | 50 |
| Plainview WD | Plainview, NY | 94 of 124 | 3.26 ppb | 35,000 |
| Town of Hempstead Water Department | East Meadow, NY | 15 of 23 | 2.92 ppb | 110,000 |
| Westbury WD | Westbury, NY | 6 of 12 | 2.88 ppb | 20,500 |
| Boe Del Heights Mutual Water | Indio, CA | 4 of 8 | 2.53 ppb | 325 |
| Bethpage WD | Bethpage, NY | 96 of 155 | 2.44 ppb | 33,000 |
| City of Chino | Chino, CA | 47 of 237 | 2.40 ppb | 18,907 |
| Stallion Springs Community Services District | Tehachapi, CA | 18 of 48 | 2.40 ppb | 2,488 |
| Ontario Municipal Utilities Company | Ontario, CA | 14 of 14 | 2.29 ppb | 167,382 |
| Glen Cove City | Glen Cove, NY | 11 of 11 | 2.18 ppb | 28,000 |
| Roslyn WD* | Roslyn, NY | 2 of 2 | 2.15 ppb | 18,000 |
| Hicksville WD | Hicksville, NY | 88 of 98 | 2.12 ppb | 47,810 |
| Herring Cove Condominiums Trust | Plymouth, MA | 18 of 19 | 2.10 ppb | 25 |
| Loma Linda Power Plant | Loma Linda, CA | 7 of 12 | 1.97 ppb | 10,500 |
| Las Flores Water Company | Altadena, CA | 44 of 108 | 1.94 ppb | 4,500 |
| South Huntington Water Department | South Huntington, NY | 1 of 1 | 1.90 ppb | 81,760 |
| Jericho Water District | Syosset, NY | 17 of 35 | 1.50 ppb | 58,000 |
| Carpinteria Valley Water District | Carpinteria, CA | 1 of 2 | 1.50 ppb | 16,050 |
| Sturbridge Water Department | Sturbridge, MA | 41 of 42 | 1.40 ppb | 4,592 |
| Valencia Heights Water Company | West Covina, CA | 21 of 86 | 1.34 ppb | 5,500 |
| Page Avenue Mutual Water Company | Fullerton, CA | 1 of 4 | 1.28 ppb | 115 |
| San Martin County Water District | Morgan Hill, CA | 7 of 23 | 1.27 ppb | 614 |
| Valley Water Company | La Canada Flintridge, CA | 16 of 56 | 1.26 ppb | 9,900 |
| Redlands City | Redlands, CA | 139 of 304 | 1.25 ppb | 80,000 |
* 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 Perchlorate, but it likely has the contaminant in its water supply.
| Utility | Location | Tests | Average level | People served |
|---|---|---|---|---|
| Riverhead WD* | Riverhead, NY | 1 of 1 | 6.75 ppb | 37,050 |
| La Verne WD | La Verne, CA | 57 of 73 | 5.85 ppb | 32,230 |
| Plainview WD | Plainview, NY | 94 of 124 | 3.26 ppb | 35,000 |
| Town of Hempstead Water Department | East Meadow, NY | 15 of 23 | 2.92 ppb | 110,000 |
| Westbury WD | Westbury, NY | 6 of 12 | 2.88 ppb | 20,500 |
| Bethpage WD | Bethpage, NY | 96 of 155 | 2.44 ppb | 33,000 |
| City of Chino | Chino, CA | 47 of 237 | 2.40 ppb | 18,907 |
| Ontario Municipal Utilities Company | Ontario, CA | 14 of 14 | 2.29 ppb | 167,382 |
| Glen Cove City | Glen Cove, NY | 11 of 11 | 2.18 ppb | 28,000 |
| Roslyn WD* | Roslyn, NY | 2 of 2 | 2.15 ppb | 18,000 |
| Hicksville WD | Hicksville, NY | 88 of 98 | 2.12 ppb | 47,810 |
| Loma Linda Power Plant | Loma Linda, CA | 7 of 12 | 1.97 ppb | 10,500 |
| South Huntington Water Department | South Huntington, NY | 1 of 1 | 1.90 ppb | 81,760 |
| Jericho Water District | Syosset, NY | 17 of 35 | 1.50 ppb | 58,000 |
| Carpinteria Valley Water District | Carpinteria, CA | 1 of 2 | 1.50 ppb | 16,050 |
| Redlands City | Redlands, CA | 139 of 304 | 1.25 ppb | 80,000 |
| Mineola | Mineola, NY | 12 of 18 | 1.25 ppb | 20,600 |
| Garden City | Garden City, NY | 6 of 16 | 1.18 ppb | 25,000 |
| WA of Great Neck North | Great Neck, NY | 4 of 12 | 1.12 ppb | 31,400 |
| City of Upland* | Upland, CA | 3 of 16 | 0.969 ppb | 78,791 |
| Water Authority of Western Nassau | Floral Park, NY | 4 of 6 | 0.950 ppb | 120,000 |
| San Bernardino City* | San Bernardino, CA | 212 of 277 | 0.932 ppb | 188,931 |
| Monte Vista Water District* | Montclair, CA | 8 of 47 | 0.898 ppb | 54,460 |
| Azusa Light and Water | Azusa, CA | 16 of 136 | 0.826 ppb | 110,000 |
| Monrovia Water Department | Monrovia, CA | 16 of 120 | 0.814 ppb | 36,590 |
| West Valley Water District* | Rialto, CA | 37 of 232 | 0.801 ppb | 72,647 |
| Golden State Water Company - West Orange | Anaheim, CA | 3 of 19 | 0.705 ppb | 114,016 |
| Rubidoux Community SD* | Rubidoux, CA | 5 of 36 | 0.664 ppb | 26,150 |
| Hempstead | Hempstead, NY | 1 of 4 | 0.650 ppb | 56,000 |
| Falmouth Water Department | Falmouth, MA | 4 of 7 | 0.643 ppb | 77,500 |
* 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 Perchlorate, but it likely has the contaminant in its water supply.