Lots of pipes run under our streets. Storm drains safely take water to the river with out causing erosion damage to the road or soil around town. Other pipes include sanitary sewer lines, Public water supply, Natural gas supply, Electrical supply, and communication wires.
The Vactor Truck uses air suction along with water to remove blockages from sewer and storm catch basins. Blockages can be from dirt and gravel in the storm system to grease and rags in the sewer system.   
The garbage truck serves a necessary purpose. Don't get stuck behind one in the summer or you may smell something unplesant.    
The Water Truck washes the streets and transports water where needed.
The Chipper Truck cleans up brush and tree limbs by grinding them up. they get transported to the Waste Water Treatment Plant for use.
The Salt Barn houses salt for use on the roads in the winter.