Emergency Discharge Permit for Discharge of Treated Effluent from the Grass Valley Wastewater Treatment Plant to Grass Valley Creek

Emergency Discharge Permit for Discharge of Treated Effluent from the Grass Valley Wastewater Treatment Plant to Grass Valley Creek

The proposed action being considered is the continued discharge of excess treated effluent from the Grass Valley WWTP to Grass Valley Creek during emergency conditions caused by excess precipitation and snow melt. Such emergency conditions are random, intermittent events dictated by natural rainfall events, but the District believes it is in the best interests of both the District and the Regional Board to convert these current unauthorized discharges to authorized discharges based on the data assembled to support this proposed Negative Declaration. The only proposal to modify the Grass Valley WWTP facilities or normal operations in conjunction with these emergency discharges is to replace the existing chlorination system with an ultraviolet (UV) disinfection system or a dechlorination system which would be added and utilized prior to discharge to the creek under an authorized permit. Since there is no existing approved stream flow/volume measuring gauge, the District proposes to install such a stream gauge on Grass Valley Creek. The stream gauge would be installed on the existing concrete spillway at Grass Valley Lake, with no disturbance to the natural channel of Grass Valley Creek. The only other activity proposed in conjunction with this emergency discharge is to collect samples of the treated effluent in accordance with a sample analysis plan to verify that the effluent does not contain any pollutants that could significantly degrade the water quality of Grass Valley Creek.

San Bernardino