Arsenic, dissolved

Overview

Arsenic is a nonmetallic element that commonly is found at small concentrations in surface waters, but larger concentrations can be found in ground water because of increased solubility in the absence of oxygen. Arsenic is found included in sulfide minerals, such as pyrite, in association with iron hydroxides, associated with burning of coals, and as a pesticide or pesticide additive.

Water-quality standards and criteria are developed by the States, approved by the U.S. Environmental Protection Agency (USEPA), and then promulgated (passed into law) as standards by each State. Graphs on this website allow comparison of measured and computed data to these standards and criteria by plotting them as straight lines. When evaluating data to decide whether water quality is suitable for the intended use, viewers are cautioned to consider the uncertainty associated with these computed data.