Basic Information

In 2001, EPA announced that the final standard for arsenic in drinking water of 10 micrograms per liter (µg/L) would replace the old limit of 50 µg/L. The new rule became effective in February 2002. EPA has provided $23 million for the research and development of more cost-effective technologies, as well as training and technical assistance to operators of small systems to reduce their compliance costs.

As part of this effort, EPA’s Arsenic Research Program fills in research gaps for a number of technologies and compliance approaches, and provides information to utilities, engineering firms, regulatory officials, and others. In addition to developing training materials, software, and design manuals, EPA conducts:

Treatment technology demonstrations
Short-term performance verification studies of commercially ready arsenic treatment technologies
Research that emphasizes:

Arsenic is an element found naturally in soil, the bedrock that underlies the soil, in ground water, and in ocean water. It’s also found in trace amounts in lakes and rivers. Natural activities such as erosion of rocks, volcanic action, and forest fires can release arsenic into the environment.

Human activities can also release arsenic into the environment through animal feeding operations, using certain fertilizers, and industry practices such as mining, copper smelting, and coal burning. We use arsenic as a wood preservative, and we use it in paints, dyes, metals, drugs, soaps, and semiconductors.

Arsenic reacts with other chemicals to form compounds that can be taken up by living tissue in both plants and animals. Because it is a naturally occurring part of the environment, trace amounts of arsenic can be found in fruits and vegetables, as well as in animals that are used as food.

In areas where the environment contains high levels of arsenic, the drinking water can end up with potentially toxic levels. Higher levels of arsenic tend to be found in ground water than in surface water. Municipal drinking water systems and use of private water wells can place a high demand on ground water sources; this may cause water levels to drop and release arsenic from rock formations.

Furthermore, research has shown that arsenic can accumulate in solids found in drinking water distribution systems. Significant accumulation was even observed in solids exposed to water containing arsenic levels below the Maximum Contamination Level of 10 µg/L. Limiting arsenic releases from distribution system solids can help avoid elevated arsenic levels at our taps.

Arsenic is an essential trace element for some animals and perhaps for humans, but the necessary intake may be only 0.01 milligrams per day. Arsenic can also be a highly toxic poison. Long-term exposure to arsenic through drinking water can cause skin, lung, bladder, and kidney cancer. It can also cause thickening of the skin and pigmentation changes.

Technical Contact:

Tom Sorg (513) 569-7370

Basic Information

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