Sulfate, dissolved

Overview

Sulfate contributes to the dissolved solids in water and can be added to a stream through irrigation return flow, which could cause sulfate concentrations to be increase because of evapotranspiration. Sulfate originates from evaporate deposits such as gypsum and the oxidation of sulfide minerals such as pyrite. High sulfate concentrations are undesirable because the water would be less useable as a drinking-water source.

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.