In this new 12.5 million-gallon circular covered storage tank, the inlet and outlet are located on diametrically opposite sides of the tank. While there were no specific T10 requirements, the Massachusetts Water Authority desired a tank with relatively small recirculation zones and good flow characteristics.Several alternate configurations were evaluated. The chosen configuration, which involved the use of a vertical inlet and a 4 percent porous baffle placed a short distance downstream of the inlet, provided a compromise between cost, ease of construction, and water quality.