(72) Essential Services: The erection, construction, alteration or maintenance by public utilities or municipal or other governmental agencies, of underground gas, electrical, steam or water transmission or distribution systems, collection, communications, supply or disposal systems, or sites, including poles, wires, mains, drains, sewers, pipes, traffic signals, hydrants, or similar equipment and accessories in connection therewith, which are reasonably necessary for the furnishing of adequate service by such public utilities or municipal or other governmental agencies or for the public health, safety or general welfare, but not including buildings.