Sulfate can be naturally occurring in Iowa water bodies, or the result of municipal and industrial discharges. When naturally occurring, they are often the result of the breakdown of plant litter. Runoff from fertilized agricultural lands also contributes to the Upper Wapsipinicon River Watershed. Sulfur is an essential plant nutrient, too much or too little can be detrimental to aquatic organisms. Too much sulfate is detrimental due to its effect on the pH of waters in the UWRW. The Iowa DNR released, Water Quality Standards Review: Chloride, Sulfate and Total Dissolved Solids a study examining the effects of sulfate and chloride on aquatic ecosystems in Iowa.