At 0708hrs, Station 31 was dispatched to cover North Brunswick while the operated on a Hazmat Call on Rt. 1. Engine 31 responded to Company 3 on Cozzens Ln. While En-route Engine 31 got dispatched to a call in North Brunswick for a Gas Leak. Engine 31 covered North Brunswick for 6 1/2 hours and took 4 cover assignment calls.