The main contractor was also responsible for furnishing and installing all electrical, control, detection and instrumentation work, cranes, hoists and miscellaneous metals. The company was also responsible for architectural work and interior structures, which include aluminium stairways, fibreglass gratings and concrete decks. Concrete beams, masonry and earthtone brick columns, and architectural arches were used to ensure the plant blended in with existing structures. The new Deer Island treatment plant has been designed to meet the environmental protection mandates of the Federal Clean Water Act. Today it is more than 800 million gallons per day.
Primary treatment does it through gravity settling.
Because space is in demand on Deer Island, the new plant was designed with stacked settling tanks for the removal of solids. These two story tanks provide twice the area for settling, achieving a higher rate of solids removal in the same space. Solids removed by gravity settling eventually go to one of the plant's 12 new egg-shaped sludge digesters. Digestion readies sludge for conversion to fertiliser. Microorganisms in the digesters grow by consuming sludge and breaking down the organic matter while producing methane gas.