Addressing the fast-rising cost of energy is rightly high on today’s agenda, so when four hefty 40HP rotors serving one’s aeration plant are also sitting at the top of your maintenance budget, finding a better means of mixing certainly concentrates the mind. In Huntsville, Arkansas, the route to achieving optimum mixing of its oxidation ditches has been a marathon, not a sprint; but this meticulously operated wastewater treatment plant is now reaping the rewards of significantly reduced horsepower and reduced repair costs. Managing oxygen levels at Huntsville has been a major, fluctuating challenge, especially with the wastewater taken in from a large-scale food manufacturer, nearby. The 160HP (total) rotors had to run 24/7 in order to sufficiently mix and add oxygen to Huntsville’s WWTP aeration basin, but when the expanding food manufacturer upgraded its own treatment plant, the problematical rotors were creating far too much oxygen; contaminating the anaerobic and anoxic zones.…