This is an overview of the area of the pipeline relocation. Some of the pumps, manifolds and temporary above ground lines can be seen. The pumps and plumbing were set up and ran 24 hours a day for several days while a section of the underground pipeline was moved.

Focusing a little closer, there are 12 pumps in 2 groups of 6. Each set of 6 draws the sewage from a single manhole. In the foreground, you can see the suction lines from the pumps  converge and go down into one of the manholes.

Closer still, you can see one of the 2 upstream manholes. They are about 5 feet in diameter and go down about 15 feet to the main line, itself a 5 foot inside diameter concrete pipe. A section of new concrete pipe can be see on the right.

The pumps are Godwin Dri Prime model DPC300. Each pump is driven by a 140HP diesel engine and can pump 5,000 gallons per minute. The pumps autostart from a float mechanism in the manhole and prime themselves. The pumps come online and shut down automatically to match the sewage flow rate. Only the number of pumps necessary to match the flow rate are running at any given time.

The pump and engine are mounted on a skid base which also serves as a fuel tank. For extended continuous running, the engines draw diesel fuel from an external tank at the left. 12" PVC (1" wall) connects to the pump inlet and discharge.

Each pump feeds a 12" line. The lines converge to 2 manifolds that feed 3 18" lines each. Each of the 12 pump lines connect to a manifold through a one way flap valve. The valves prevent the unpressurized lines connected to inactive pumps from being back fed from the pressurized lines of running pumps. The 12 valves are bolted to the left side of the manifolds. Thanks to the pumps and valves, contrary to a popular saying, "things" always flow uphill in this job!

The 6 18" lines on their way to the discharge manhole. Except at the pump and manifold interfaces, there are no bolted joints. high density polyethylene (HDPE) pipe sections are joined into a continuous length by a fusion machine that trims the sections, heats the ends and then presses  them together until they cool, forming a fused joint as strong as the original pipe. The elbow sections are fabricated as needed by cutting and joining multiple short sections at an angle. When the job is complete, the lines are simply sawed up into 40 foot truckable lengths to be reused on another job.