Water quality standards are important because they help to protect and restore the quality of the Nation's surface waters, consistent with the requirements of the Clean Water Act. Standards help to identify water quality problems caused by, for example, improperly treated wastewater discharges, runoff or discharges from active or abandoned mining sites, sediment, fertilizers, and chemicals from agricultural areas, and erosion of stream banks caused by improper grazing practices. Standards also support efforts to achieve and maintain protective water quality conditions, including: