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Arsenic is a naturally occurring element in the earth's crust. It is widely distributed throughout rocks and soil. It can also be released into the environment from agricultural and industrial activities, such as copper and lead smelting, and wood treatments.

In our environment, it can enter the air and water, and can concentrate in some foods we eat. Inorganic arsenic in both drinking water and dietary sources are the primary concerns and sources of environmental exposure for the general population. Organic arsenic compounds, which are abundant in seafood, are less harmful to health.

Possible health concerns from excessive exposure to arsenic typically are associated with long-term exposure to high levels of inorganic arsenic. Long term exposure may cause urinary bladder, lung, and skin cancers.

Learn more about Arsenic and Health.

Levels of various naturally-occurring and man-made contaminants in New Mexico groundwater including arsenic, might be elevated above the Environmental Protection Agency (EPA) Safe Drinking Water standards. Ongoing drought conditions and aquifer mining have raised further concern that increases in contaminants may occur in the absence of significant ground water recharge events. To assure that the water is safe for human consumption, well owners should periodically test their wells.

The information available on this page, including the maps, demonstrates arsenic found in tested private wells in New Mexico based on the data available from various sources.

To know the arsenic concentration in your water from your own well, you need to test. Learn about testing.

Wells Sampled 1973-2018

Arsenic levels in water samples from private wells vary between New Mexico counties and even within the same county.
There appears to be higher arsenic levels in central New Mexico counties based on the data that are available.
The groundwater system in New Mexico is very complex. This complexity can lead to large arsenic concentration variability even among neighboring wells. Therefore, to know the arsenic concentration in your water from your own well, you need totest.

The safe drinking water concentration for arsenic is 10 mcg/L and some of the water samples from wells in counties (with greater than 20 samples) appear to exceed this this Environmental Protection Agency (EPA) Safe Drinking Water standard. Based on data available, counties without water samples that exceed the EPA drinking water standard include: Curry, Chaves, Mora, and Quay counties.

People who drink water containing arsenic in excess of EPA's standard and over many years could experience health problems.
Learn more about Arsenic and Health.Arsenic Distribution in NM private wells 1973-2018

Arsenic Distribution in New Mexico Private Wells (Wells Sampled Nov 1973 - Oct 2018
Arsenic Distribution in New Mexico Private Wells (Wells Sampled Nov 1973 - Oct 2018
New Mexico Private Wells Inventory (Arsenic Test Results Summary Nov 1973 - Oct 2018