Ribbon Cutting Takes Place for Memorial Beach Water Treatment Plant
Tighe & Bond engineers gathered with State and local officials for the ribbon-cutting ceremony for the Memorial Beach Water Treatment Plant (WTP) in Webster, Massachusetts. The WTP is an approximate 5,000 square foot block building with brick veneer constructed on the Water Department’s Pump Station No. 2 site near Memorial Beach. The WTP was constructed to filter iron and manganese from the groundwater of Pump Station No. 1 and Pump Station No. 2, which includes a total of six groundwater wells with a withdrawal capacity of 2,750,000 gallons per day. This project connected these two pump stations by repurposing an existing 1,000 linear foot water main.
Raw water from the six wells is initially conveyed to the top of a packed aeration tower for carbon dioxide removal, a natural way to increase raw water pH. Water is then discharged to a tank located within the corrosion control building referred to as the Aerated Water Clearwell. Aerated Water Pumps then convey this water to the adjacent WTP.
Water is then pretreated with chemicals for oxidation and pH control and then is conveyed to the GreensandPlus™ pressure filters. Water then enters a tank underneath the floor of the WTP referred to as the Backwash Supply/Finished Water Clearwell. When the water distribution system has a need for water the finished water pumps turn on and convey water from the finished water clearwell to the distribution system. This water receives post-filtration chemical adjustment for additional pH control, disinfection, and alkalinity adjustment if needed.
Periodically the GreensandPlus™ pressure filters become effectively clogged with filtered iron and manganese and received backwash. A filter is taken offline, drained and backwash Supply Pumps convey water from the Backwash Supply/Finished Water Clearwell backward through the filter. The backwash wastewater which contains concentrated iron and manganese particles is discharged to the Backwash Waste / Recycle Tank. Once settled the water at the top of this tank is clear enough to bring to the beginning of the water treatment plant again. Recycle Pumps are sued to convey this water to the aeration tower. The water at the bottom of the Backwash Waste / Recycle Tank contains the further concentrated iron and manganese water. This water is conveyed to the Town sewer collection system by backwash waste pumps.