Donohue & Associates and the City of Indianapolis, Indiana, received an Honor Award in the 2006 ACEC Indiana Engineering Excellence competition. The award recognizes the design and construction of White River CSO Outfall 039, a 3-million-gallon underground storage and primary treatment structure. The project, which was also a national finalist, was built to significantly reduce combined sewage overflows into the White River. The aesthetically-pleasing facilities capture, treat, and store wastewater and storm water until flows can be sent to the wastewater treatment facility.

The project is located in a high profile downtown area, near the IUPUI-Indianapolis stadium and baseball field, White River State Park, City Zoo, and a heavily used river walk. The cast-in-place concrete structure was constructed completely below grade in the White River floodplain and covered with topsoil and grass. Cleverly tucked into the embankment, the structure's electrical and automated control building provides an overlook for individuals enjoying the scenic river walk.

Innovative engineering practices were utilized to meet the challenging and unique needs of this project, including automated flushing gates to clean out the structure and minimize odors, and thickened and heavily reinforced floor slab to prevent the structure from rising during flooding.