The current phenol concentration levels are above the allowable phenol concentration in the river fixed by local regulations at 0.005 mg/L. Assuming Fuzzy Chemicals implements a 70% reduction of phenol concentration in their outflow. What percent reduction in phenol does Super Agra need to achieve in order to keep the downstream phenol concentration never above 0.005 mg/L? 80% 90% 70% 99%