NOTICE OF SCITUATE WASTE WATER TREATMENT PLANT DISCHARGE
On Wednesday April 27, 2016 at 6:45 P.M. there was a power fluctuation at the Scituate Waste Water Treatment Plant (WWTP). This power fluctuation caused a surge in the power system which shutdown a Programmable Logic Controller or “Brain” (PLC) for the secondary treatment process. The shutdown of the PLC caused the clarifiers to discharge 930,000 gallons of grey water to the storm drains in the North River. At this time, the Town is still investigating what caused this power fluctuation.
Grey water is effluent that has been treated thru the primary process in the plant and as a result has higher nitrogen and bacteria count then typical outflow. Although the risks to exposure are believed to be low the clam flats were shut down as a precaution by the Shellfish Warden and the Division of Marine Fisheries. The clam flats will be shut down for a minimum of seven days and potentially up to 21 days. The river will have regular water sampling tests during this period.
At no time was there any danger to the public drinking water supply.
The power fluctuation was discovered by personnel on Thursday, April 28, 2016 at 6:45 A.M. and fully corrected by 7:30 A.M. On Friday, and over the weekend, all operational systems were reviewed to ensure the facility was functioning properly and that there was no risk of further discharges.
The Town notified the Department of Environmental Protection, the Environmental Protection Agency, the Division of Marine Fisheries, Board of Health, Shellfish Warden, Harbormaster, and Board of Selectmen of the issues as soon as it was discovered.
The Town was also in contact with the North and South Rivers Watershed Association.
The Town remained in contact with each agency during the response.
New SCADA (Secondary Control and Data Acquisition Controls) logic has been added to the plant to prevent this type of failure in the future.