components and relative positions with respect to the process flow are shown in fig1 a center in tank up flow column module as illustrated in the drawing could receive piped in flow from a hydro source while setting in a natural catch basin or in a channel basic components of an exemplary embodiment are shown in fig1 a vertical tower 10 capped with a covered header 26 is seated in an open tank 11 a water inlet manifold 12 and a water overflow fitting 13 are attached to tank 11 tower 10 has bottom openings scavenger column s 14 and down flow column s 15 are spaced around the tower header 10 open tank 11 is supported over a separate drained catch basin scavenger and down flow column s 14 and 15 extending downward penetrate the tank 11 bottom and protrude into the catch basin below the basin drain level sealing glands 16 close the clearances at the tank 11 base penetrations removable tower header cover 27 seated on the top rim of header 26 and sealed using leak tight o ring or equal sealing medium is held securely in place once vacuum is applied simple latches 31 see fig2 which hold the cover 27 in position during shipment erection and start up also allow easy access to the header for maintenance internal scoop 32 mounted inside of header 26 connects to scavenger column header 22 are shown in fig2 this provides a means for removing floatable materials and debris from the tower header 26 the vacuum producing interaction between cascading.