23 Counties With the Most Contaminated Water

Source: Wesley Fryer / Flickr

8. Jackson County, Oklahoma
> Water system: Altus
> Number of max. contaminant level violations since 1980: 84
> Population served by water system: 21,477
> Most recent violation: March 24, 2017

The EPA has cited the Altus municipal water system for 84 water quality violations since 1987, mostly for high levels of trihalomethanes, which at high concentrations can increase the risk of cancer and certain birth defects. One main site of contamination in the district is the Altus Air Force Base, which tested positive for high levels of trihalomethanes in early 2015. The number of violations in Altus spiked in 2014 and 2015, several years after the city had to close its water treatment facility due to filtration difficulties. Altus completed a new facility in April 2016 and has not received a violation since March 2017.

Source: Thomas & Dianne Jones / Flickr

7. Okmulgee County, Oklahoma
> Water system: Okmulgee
> Number of max. contaminant level violations since 1980: 89
> Population served by water system: 13,495
> Most recent violation: June 30, 2017

An estimated 20.8% of Okmulgee residents live in poverty, far more than the 15.5% national poverty rate. While poor communities often have fewer resources to prevent industrial polluters from encroaching on their land and are more likely to be victims of pollution, most of the violations issued to the Okmulgee water system can be traced back to the water system itself. Of the 89 water quality violations the EPA issued to Okmulgee since 1991, 87 were for total trihalomethanes and haloacetic acids, byproducts of the water disinfection process. At high levels, total trihalomethanes and haloacetic acids can increase the risk of cancer and certain birth defects.

Source: Gregg Tavares / Flickr

6. Kings County, California
> Water system: City of Hanford
> Number of max. contaminant level violations since 1980: 109
> Population served by water system: 59,338
> Most recent violation: February 16, 2015

Poor communities are often at the greatest risk of pollution and water contamination. In Kings County, 22.6% of residents live in poverty, a far higher poverty rate than the 15.5% national rate and among the most of any county nationwide. In addition to the 109 water quality violations the City of Hanford water district has received for arsenic and coliform over the last four decades, Hanford has some of the worst air pollution of any U.S. city.

Source: Melissa / Flickr

5. St. Francois County, Missouri
> Water system: Farmington
> Number of max. contaminant level violations since 1980: 118
> Population served by water system: 19,351
> Most recent violation: February 29, 2016

The EPA issued a whopping 118 violations to the Farmington water system, 98 of which were for various kinds of radionuclides. Radionuclides occur naturally in soil as a result of radioactive decay. As radioactive materials decay they emit radiation, and the ones that have longer half-lives and emit radiation over a longer time cause the most damage to human health. The known harmful variations of radiation are called alpha, beta, gamma, and neutron. There may be traces of the alpha variety in St. Francois County’s water supply.

Source: Nicolas Henderson / Flickr

4. Andrews County, Texas
> Water system: City of Andrews
> Number of max. contaminant level violations since 1980: 132
> Population served by water system: 11,088
> Most recent violation: January 4, 2017

The City of Andrews water system has received 132 water violations from the EPA since 1982, the fourth most of any municipal water system. All of these violations are for having excess fluoride and arsenic in the water supply, except for one incident of excess coliform in 1991. Excessive consumption of both fluoride and arsenic can cause adverse health issues over time. Fluorosis is a condition that develops due to drinking water with too much fluoride. Long-term complications include severe skeletal problems and damaged tooth enamel. In an attempt to improve water quality, the City of Andrews introduced a new water treatment technology in the past decade, which is supposed to lower the water’s exposure to fluoride and arsenic.