State Report

Montana

Total Water Systems

753

Total Contaminants

65

Montana

's Water

Montana relies on pristine snowmelt-fed rivers, glacial lakes, and extensive groundwater aquifers as its primary water sources. While much of the state's water boasts exceptional natural purity, concerns arise from mining activities, agricultural runoff, and localized issues with arsenic in groundwater. These challenges highlight the need for vigilant water quality monitoring.

Montana

Total Water Systems

753

Total Contaminants

65

Montana relies on pristine snowmelt-fed rivers, glacial lakes, and extensive groundwater aquifers as its primary water sources. While much of the state's water boasts exceptional natural purity, concerns arise from mining activities, agricultural runoff, and localized issues with arsenic in groundwater. These challenges highlight the need for vigilant water quality monitoring.

Largest Contaminants

Nitrate and nitrite

Water Systems Affected

689

People Impacted

718,202

Risk Level

45

/100

Learn more

Total trihalomethanes

Water Systems Affected

273

People Impacted

595,529

Risk Level

75

/100

Learn more

Bromodichloromethane

Water Systems Affected

230

People Impacted

580,007

Risk Level

70

/100

Learn more

Haloacetic acids

Water Systems Affected

237

People Impacted

577,920

Risk Level

45

/100

Learn more

Chloroform

Water Systems Affected

235

People Impacted

569,491

Risk Level

78

/100

Learn more

Bromochloroacetic acid

Water Systems Affected

191

People Impacted

533,281

Risk Level

65

/100

Learn more
Montana's Water Quality Analysis

Montana's Water Quality: An Urgent Review of Contaminants and Public Health Impacts

Overall Health Analysis

Montana’s water systems are a vital resource serving over a million people, yet they face significant challenges. Recent data shows a concerning presence of 65 different contaminants across the state’s 753 water systems. Alarmingly, the top six contaminants—Nitrate and nitrite, Total trihalomethanes, Haloacetic acids, Bromodichloromethane, Chloroform, and Bromochloroacetic acid—impact hundreds of thousands of residents. The presence of these pollutants stems from a combination of industrial, agricultural, and natural sources, posing serious health risks to the population. Addressing these contaminants is crucial to securing Montana's water safety and public health for future generations.

Top Six Contaminants

1. Nitrate and Nitrite

Water Systems Affected: 689

Population Impacted: 718,202

Nitrates and nitrites often enter water sources through agricultural fertilizers, septic systems, and animal waste. These compounds pose severe health risks, particularly to infants and pregnant women, as they can interfere with oxygen transport in the blood, leading to a potentially fatal condition called methemoglobinemia or "blue baby syndrome."

2. Total Trihalomethanes (TTHMs)

Water Systems Affected: 273

Population Impacted: 595,529

Total Trihalomethanes form as byproducts of disinfection processes when chlorine reacts with organic matter in water. Prolonged exposure to TTHMs has been linked to elevated cancer risks, particularly bladder cancer. These compounds also affect liver and kidney function, raising significant concerns for chronic exposure.

3. Haloacetic Acids (HAAs)

Water Systems Affected: 230

Population Impacted: 580,007

Haloacetic acids are another class of disinfection byproducts. Like TTHMs, they form when disinfectants used in water treatment react with organic material. These compounds are associated with cancer risks, as well as developmental and reproductive effects, making them particularly dangerous for pregnant women and young children.

4. Bromodichloromethane

Water Systems Affected: 237

Population Impacted: 577,920

Bromodichloromethane is a specific type of trihalomethane that arises during chlorination processes in water treatment. This contaminant is especially alarming due to its carcinogenic properties and potential to harm the central nervous system, liver, and kidneys over long-term exposure.

5. Chloroform

Water Systems Affected: 235

Population Impacted: 569,491

Chloroform, another disinfection byproduct, is commonly found in chlorinated water supplies. It has been linked to increased cancer risk, particularly cancer of the liver and kidneys. Additionally, chloroform exposure may lead to neurological effects, including dizziness and fatigue.

6. Bromochloroacetic Acid

Water Systems Affected: 191

Population Impacted: 533,281

Bromochloroacetic acid is a lesser-known but equally concerning contaminant formed during disinfection. Emerging research suggests this acid may contribute to cancer development and impact cellular DNA, posing long-term risks to public health.

Most Significant Health Impacts

The top contaminants in Montana’s water carry significant health repercussions, including a heightened risk of various cancers, organ damage, and developmental and reproductive issues. Vulnerable populations such as infants, pregnant women, and the elderly face even more severe consequences. Infants are particularly at risk from nitrates, while TTHMs and HAAs pose risks for chronic diseases like cancer and lifelong organ damage. Poor water quality can exacerbate existing health conditions, making access to clean, safe water an urgent necessity for all Montanans.

Conclusion

Montana’s water health paints a troubling picture, with widespread contamination affecting both urban and rural communities. While disinfection processes improve microbial safety, they also introduce hazardous byproducts like TTHMs and HAAs, creating complex trade-offs. Addressing this issue requires community action, updated regulations, and investment in advanced filtration technologies. Public awareness of the contaminants and their impacts is essential to safeguarding the health of Montana’s residents. By taking proactive steps to understand water quality issues, communities can work together for a healthier, cleaner future.

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