Notably, profitability depends largely upon rate relief at regular intervals for its different service areas. Consequently, Duke Energy continues to bear huge expenses related to the Dan River incident. On Sept 23, 2016, Duke Energy Carolinas entered into an agreement with the North Carolina Department of Environmental Quality (NCDEQ), under which the former agreed to pay $6 million. The agreement was aimed at resolving allegations underlying the asserted civil penalty related to the Dan River coal ash release and alleging unpermitted discharges at the facility. Moreover, potential volatility in market prices of fuel, electricity and other renewable energy commodities might create operational risks for Duke Energy. In addition, unfavorable supply costs for providing full energy and capacity requirement services may have an undesirable impact on the company's earnings.