National Drinking Water Database
National Drinking Water Database - Chemical Contaminants
Bromate
Status: Regulated - EPA has established a maximum legal limit in tapwater for this contaminant.
Bromate is a carcinogenic disinfection byproduct of ozonation formed when source waters contain high levels of natural bromide; it can also form following water treatment with chlorine dioxide or hypochlorite. [read more]
Detected |
Found above health guidelines |
Found above legal limit |
|
|---|---|---|---|
| States | 18 |
18 |
11 |
| Water utilities | 83 |
83 |
19 |
| People Served | 9,925,574 |
9,925,574 |
1,444,937 |
Bromate Exposure by State
Water utilities in 18 states have reported detecting Bromate in treated tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies.
| State | Water Suppliers with Bromate contamination | Water suppliers reporting Bromate above health-based limits | ||
|---|---|---|---|---|
| Systems | Population | Systems | Population | |
| California | 20 | 5,081,839 | 20 | 5,081,839 |
| Florida | 7 | 1,729,710 | 7 | 1,729,710 |
| Nevada | 8 | 1,493,990 | 8 | 1,493,990 |
| Wisconsin | 5 | 762,567 | 5 | 762,567 |
| Massachusetts | 8 | 245,662 | 8 | 245,662 |
| Arizona | 2 | 186,000 | 2 | 186,000 |
| North Dakota | 1 | 90,599 | 1 | 90,599 |
| Oregon | 3 | 89,489 | 3 | 89,489 |
| Wyoming | 3 | 86,207 | 3 | 86,207 |
| North Carolina | 1 | 83,210 | 1 | 83,210 |
| Minnesota | 1 | 34,500 | 1 | 34,500 |
| New Mexico | 2 | 9,631 | 2 | 9,631 |
| Arkansas | 1 | 9,055 | 1 | 9,055 |
| Virginia | 1 | 8,300 | 1 | 8,300 |
| Iowa | 1 | 5,557 | 1 | 5,557 |
| Indiana | 4 | 5,539 | 4 | 5,539 |
| Washington | 13 | 2,918 | 13 | 2,918 |
| Illinois | 2 | 801 | 2 | 801 |
| Total | 83 | 9,925,574 | 83 | 9,925,574 |
The Most Polluted Communities
83 water utilities reported detecting Bromate in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies
Ranked by highest average Bromate level
| Rank | System | Population Served | Positive test results of total reported tests | Average Level (Range) |
|---|---|---|---|---|
| 1 | Bassi Ranch Mutual Water Co. San Luis Obispo, CA | 85 | 4 of 4 | 18.28 ppb (5.1 to 29 ppb) |
| 2 | Golden State Water Company - Bay Point Rancho Cordova, CA | 16,715 | 2 of 2 | 9.15 ppb (6.3 to 12 ppb) |
| 3 | City of Fargo Fargo, ND | 90,599 | 7 of 7 | 6.89 ppb (5 to 9.3 ppb) |
| 4 | Findlay Findlay, IL | 800 | 36 of 55 | 6.63 ppb (0 to 24 ppb) |
| 5 | Blacksburg-Christiansburg-Vpi Water Auth Blacksburg, VA | 8,300 | 1 of 1 | 6.57 ppb (6.57 ppb) |
| 6 | City of North Las Vegas Utilities Department N Las Vegas, NV | 282,600 | 1 of 1 | 6.35 ppb (6.35 ppb) |
| 7 | Las Vegas Valley Water District Las Vegas, NV | 1,181,263 | 1 of 1 | 6.35 ppb (6.35 ppb) |
| 8 | Big Bend Water District Laughlin, NV | 8,300 | 17 of 24 | 5.58 ppb (0 to 15 ppb) |
| 9 | Windmill Water Edgewood, NM | 1,539 | 10 of 10 | 5.11 ppb (5 to 6.1 ppb) |
| 10 | Indian Hills Gid Carson City, NV | 5,800 | 2 of 2 | 5 ppb (4 to 6 ppb) |
Health Based Limits for Bromate
| Standard | Description | Level |
|---|---|---|
| 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. | 0 ppb |
| One in one million (10-6) Cancer Risk | The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 1,000,000. Source: U.S. Environmental Protection Agency. | 0.05 ppb |
| One in ten thousand (10-4) Cancer Risk | The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 10,000. Source: U.S. Environmental Protection Agency. | 5 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. | 10 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. | 140 ppb |
| Children's health-based limit for 1-day exposure | Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency. | 200 ppb |
Testing Summary for Bromate
| Are tests routinely required for Bromate by federal law? | Yes |
| Water suppliers reporting tests for Bromate (2004-2009): | 235 of 47,576 |
| Average testing rate for water supplier reporting tests (2004-2009): | 4.2 per year |
Violation Summary for Bromate
Data from the U.S. Environmental Protection Agency includes the following violations of federal standards for Bromate since 2004
| Maximum Contaminant Level Exceedance Violations | 12 |
| Monitoring Violations | 0 |
| Reporting Violations | 0 |