National Drinking Water Database
National Drinking Water Database - Chemical Contaminants
Diquat
Status: Regulated - EPA has established a maximum legal limit in tapwater for this contaminant.
Diquat is a non-selective herbicide and dessicant used extensively for control of crop and aquatic weeds; it may cause cataracts. [read more]
Detected |
Found above health guidelines |
Found above legal limit |
|
|---|---|---|---|
| States | 12 |
- |
- |
| Water utilities | 37 |
- |
- |
| People Served | 702,926 |
- |
- |
Health Concerns for Diquat:
Diquat Exposure by State
Water utilities in 12 states have reported detecting Diquat in treated tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies.
| State | Water Suppliers with Diquat contamination | |
|---|---|---|
| Systems | Population | |
| Arizona | 3 | 240,438 |
| California | 8 | 155,284 |
| Florida | 7 | 127,164 |
| Kentucky | 4 | 67,726 |
| Oregon | 5 | 58,650 |
| Alabama | 2 | 28,842 |
| Arkansas | 1 | 11,000 |
| Nebraska | 1 | 8,000 |
| Ohio | 3 | 5,271 |
| Illinois | 1 | 300 |
| Nevada | 1 | 126 |
| Indiana | 1 | 125 |
| Total | 37 | 702,926 |
The Most Polluted Communities
37 water utilities reported detecting Diquat in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies
Ranked by highest average Diquat level
| Rank | System | Population Served | Positive test results of total reported tests | Average Level (Range) |
|---|---|---|---|---|
| 1 | Wisemans Mobile Court Colfax, OR | 100 | 1 of 2 | 2.25 ppb (0 to 4.5 ppb) |
| 2 | Brewton Water Works Brewton, AL | 9,945 | 1 of 4 | 0.87 ppb (0 to 3.48 ppb) |
| 3 | Oakridge Apartments Mt Charleston, NV | 126 | 1 of 1 | 0.77 ppb (0.77 ppb) |
| 4 | Albany Water Works Albany, KY | 16,335 | 1 of 13 | 0.77 ppb (0 to 10 ppb) |
| 5 | Travel Shores Trailer Park Fort Bragg, CA | 80 | 1 of 2 | 0.65 ppb (0 to 1.3 ppb) |
| 6 | Upper Lake County Water District Upper Lake, CA | 1,100 | 1 of 2 | 0.65 ppb (0 to 1.3 ppb) |
| 7 | Village of Racine Racine, OH | 920 | 1 of 6 | 0.58 ppb (0 to 3.5 ppb) |
| 8 | Santa Cruz Water Company Phoenix, AZ | 17,005 | 1 of 3 | 0.57 ppb (0 to 1.7 ppb) |
| 9 | North Fairfield, Vlg. of North Fairfield, OH | 573 | 1 of 5 | 0.54 ppb (0 to 2.7 ppb) |
| 10 | Lake Region Mobile Home Village Haines City, FL | 565 | 1 of 1 | 0.44 ppb (0.44 ppb) |
Health Based Limits for Diquat
| Standard | Description | Level |
|---|---|---|
| California Public Health Goals | Defined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health. | 15 ppb |
| Maximum Contaminant Limit (MCL) | The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency. | 20 ppb |
| Maximum Contaminant Limit Goal (MCLG) | A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency. | 20 ppb |
| Drinking Water Equivalent Level | A lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency. | 20 ppb |
Testing Summary for Diquat
| Are tests routinely required for Diquat by federal law? | Yes |
| Water suppliers reporting tests for Diquat (2004-2009): | 10,443 of 47,576 |
| Average testing rate for water supplier reporting tests (2004-2009): | 0.4 per year |
Violation Summary for Diquat
Data from the U.S. Environmental Protection Agency includes the following violations of federal standards for Diquat since 2004
| Maximum Contaminant Level Exceedance Violations | 0 |
| Monitoring Violations | 896 |
| Reporting Violations | 0 |
Occupational hazards
| Type of concern: | Reference: |
| Allowed workplace exposures restricted to very low doses | RTECS®- TLV/BEI,2007 |
| Allowed workplace exposures restricted to low doses | RTECS®- TLV/BEI,2007 |
Cancer
| Type of concern: | Reference: |
| One or more in vitro tests non-mammalian cells show positive mutation results | RTECS®- Environment International 1984 |
Irritation (skin, eyes, or lungs)
| Type of concern: | Reference: |
| One or more animal studies show skin irritation at high doses | RTECS®- Contact Dermatitis 1987 |
Government, industry, academic studies and classifications
| government/industry list/academic study | appears on list as | classification(s) |
| RTECS®- TLV/BEI,2007 | DIPYRIDO(1,2-A:2',1'-C)PYRAZINEDIIUM, 6,7-DIHYDRO- | • occupationally related - ACGIH TLV (human TWA) |
| RTECS®- Contact Dermatitis 1987 | DIPYRIDO(1,2-A:2',1'-C)PYRAZINEDIIUM, 6,7-DIHYDRO- | • skin - Primary skin irritant ( human ) |
| RTECS®- Environment International 1984 | DIPYRIDO(1,2-A:2',1'-C)PYRAZINEDIIUM, 6,7-DIHYDRO- | • mutagenic - Positive mutation assay: Mutation in Micro-organism (other micro-organisms ) |
references
| government/industry list/academic study | reference |
| RTECS®- TLV/BEI,2007 | RTECS®- TLV/BEI,2007 |
| RTECS®- Contact Dermatitis 1987 | RTECS®- Contact Dermatitis. Environmental and Occupational Dermatitis. (Munksgaard International Pub., c/o Publications Expediting Inc., 200 Meacham Ave., Elmont, NY 11003) V.1- 17,212,1987 |
| RTECS®- Environment International 1984 | RTECS®- Environment International. (Pergamon Press Inc., Maxwell House, Fairview Park, Elmsford, NY 10523) V.1- 10,285,1984 |
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