Donohue & Associates and the City of O'Fallon, Missouri earned a Grand Award in the 2011 ACEC Missouri Engineering Excellence competition. The award recognizes an effort to increase capacity at the City’s new reverse osmosis water softening facility, which was designed to produce 6 million gallons per day (mgd) of water but was limited to 2.9 mgd due to process deficiencies.

Donohue, with assistance from O'Fallon, conducted a root cause analysis and determined that the problem was caused by high iron content and insufficient reaction time for iron removal. Donohue developed a solution that uses spray ponds, an established but recently forgotten technology, which cost less than half of the $2.5 million capital cost of a previously recommended alternative. Following this improvement, production has increased to over 5 mgd and the facility is achieving excellent water quality.