A sewer truck is also called a Hydro Excavator; this truck is used to clean out sewer systems. Municipalities use sewer trucks for cleaning out sewer systems. Another difference here is that the sewer system will have debris other than septage. The tanks must be larger due to the size of the systems and the debris.
The sewer truck uses a wide pipe that is a foot or more in diameter. The suction power is intense, reaching speeds of up to 220 mph. On the suction nozzle is a collar that the user rotates to uncover the suction-release. This is important for when the suction is trying to pick up something too large for the pipe.
A sewer truck works to be efficient and that includes using a water jet to loosen and break down debris. They do the heavy work saving on manual labor costs. Because of the size of the tank and the debris, unloading time is twice as long as the septic truck.