SEPTIC TANK AT RIVERDALE. At Riverdale, a suburb of Toronto, Ont., a septic tank is being built on the Kew beach. A powerful centrifugal pump, with a capacity of 120 gallons a minute, has been installed to obviate the difficulty from water, and this has been found of sufficient capacity to keep the soakage from the lake and marsh in check. Two pipe-lines will parallel the lake, one on Queen street and the other along the beach, with a pumping station at the foot of Kenilworth, and the main filtering beds immediately south of the Woodbine race course. With the successful completion of the system, the residents of Ward one of East Toronto will make a strong effort to obtain permission to connect a local system with that of the city.