This animation illustrates how a standard Polychem chain and flight scraper system is assembled and installed.
Water officials have approved a project designed to retain polluted water during storms, keeping it from flowing into north Dorchester Bay, the Boston Globe reported.
The long-delayed plan finally approved by the Massachusetts Water Resources Authority board is designed to eliminate combined sewer overflows that push untreated waste straight into the harbor during heavy rainfall.
The nearly $300 million project includes a 2.1-mile tunnel near the shoreline in Dorchester and South Boston to collect the mix of storm water and sewage and hold it for processing. It also includes an odor control station at Carson Beach and a 10-million-gallon-per-day pumping station to be built at Conley Terminal in South Boston, the Globe reported.
The system, designed to handle all but the most extreme storm conditions, is expected to prevent pollution from closing the beaches to swimmers.