Abstract: A piping and flow control system for a wastewater reactor having a reaction vessel includes an influent distribution and sludge withdrawl conduit located near the bottom of the reactor, and aeration device located within the reactor, a treated effluent decanting system and an automatic control mechanism including a liquid level sensor. The influent distribution and sludge withdrawl conduit along with the aeration device are selectively flow connected with a pumping mechanism by a piping manifold which is also selectively connected to a source for influent wastewater to be treated by the reactor and sludge disposal.