During our 2013 water supply drill in Ottawa, Kansas, we had the opportunity to see a 400 gpm grass rig support a dump site operation by running a jet siphon. As we have noted several times before, jet siphons use pump capacity. How much? It is tough to quantify...but they do effect the total output of a dump site pumper. At the Ottawa drill, the dump site pumper was a 1,000 gpm pumper that was trying to draft and pump as much water as possible to an attack pumper. About 45-minutes into the drill, Cutler Grass 3571 (400 gpm) was placed into service to support a jet siphon. The grass rig drafted and supplied the jet siphon which in turn allowed the dump site pumper to increase its supply to the attack pumper. A good demonstration of using a smaller pump to support dump site operations by taking over some of the jet siphon support.