The Safe Drinking Water Act (SDWA) authorizes the USEPA to set national health-based standards for drinking water to protect humans against both naturally occurring and man-made contaminants that may be found in drinking water. US EPA, states, and water agencies/divisions then work together to make sure that these standards are met for rivers, lakes, reservoirs, springs, and groundwater wells.
Inorganic Forms of Arsenic
Inorganic arsenic compounds are used to preserve wood
In the environment, arsenic combines with oxygen, chlorine, & sulfur to form inorganic compounds
Inorganic forms are toxic
Organic Forms of arsenic
Arsenic in animals and plants combines with carbon and hydrogen to form organic arsenic compounds
Organic arsenic compounds are used as pesticides, primarily on cotton plants
Fish & shellfish can accumulate organic forms (nontoxic)
Arsenic in the Environment
Arsenic can only change its form in the environment. It cannot be destroyed.
Arsenic in air will settle to the ground or is washed out of the air by rain.
Many Arsenic compounds are easily solubilized in water due to changes in pH and temperature.
How might I be exposed to Arsenic?Eating food, drinking water, or breathing air containing Arsenic. Breathing sawdust or burning smoke from wood treated with Arsenic. Living near uncontrolled hazardous waste sites containing Arsenic. Living in areas with unusually high levels of Arsenic in rock.
What Are the Final Drinking Water Regulatory Standards for Arsenic?
• The enforceable Maximum Contaminant Level (MCL) is
- 0.01 mg/L
-10 micrograms per liter (µg/L)
- 10 parts per billion (ppb)