They may not be glamorous, but projects that enhance wastewater treatment are essential to the health and well-being of every community. These four award winners employed innovative technologies and project delivery methods to complete the work on schedule and on budget.

1. The Dale Mabry Diversion Project - Tampa, Florida

Florida Chapter American Public Works Association, 2017 Environment Project of the Year ($25 - $75 million category)

Two of the wastewater treatment plants in Hillsborough County, Florida, are more than 40 years old and costing the county millions of dollars a year to operate and repair. The $250 million Northwest Hillsborough Wastewater Consolidation Program will shut them down and consolidate wastewater treatment at the centralized Northwest Regional Water Reclamation Facility.

The first part of the project to be completed was the Dale Mabry Diversion Project. Westra Construction and the engineering firm of McKim and Creed worked together on this design/build project, which involved the construction of more than 12 miles of large-diameter force main pipe in a congested, multi-lane roadway corridor.

The project team used trenchless technology to install the pipe, employing 16 horizontal directional drills. The approach enabled the construction team to minimize traffic disruptions and avoid negative impacts to the surrounding environment.

2. Metro Denver Wastewater Reclamation District Northern Treatment Plant - Denver, Colorado

Design-Build Institute of America, 2017 Natonal Award of Merit, Water/Wastewater

Denver’s Metro Wastewater Reclamation District went the design-build route when letting this $475 million project. Work included construction of a treatment plant that can handle 24-million gallons of wastewater per day, of a 7-mile gravity interceptor and of an 11-mile pressurized force main.

Using BIM modeling software, the project team shared information about the design with all the disciplines and crafts involved in the project: architectural, structural, building mechanical, electrical, civil, process mechanical, piping and instrumentation. By using the design-build process, the project team was able to shorten the construction schedule and ensure that the project stayed within budget.

3. Ala Moana Wastewater Pump Station Force Mains #3 and #4 - Honolulu Hawaii

American Society of Civil Engineers, 2017 Outstanding Civil Engineering Achievement, Grand Award Winner/ Best Water/Wastewater Environmental Project

To comply with the terms of an EPA consent decree, the City of Honolulu added two parallel 7,500-foot-long sewer force mains to increase its capacity for carrying raw sewage from the Ala Moana Wastewater Pump Station to the Sand Island Treatment Plant.

The pipes had to be installed at 85 feet below sea level in order to cross under the only entrance to Honolulu Harbor, which could not be blocked at any time. Challenging soil conditions and the position of piers at the harbor entrance further complicated pipe placement. The project team used 3-D, state-of-the art, finite elemental model analysis to evaluate various microtuneling and jacking alternatives. They completed the project on time and under budget.

4. Liberty Utilities and Wastewater Treatment Facilities - Liberty, Missouri

Design-Build Institute of America, 2017 National Award of Merit, Water/Wastewater

Rising rates for outsourcing wastewater treatment to Kansas City plus a desire to have sufficient capacity for future development spurred the city of Liberty to build its own wastewater treatment plant.

The City awarded Goodwin Brothers Construction a $78 million design-build contract that shortened what would have been a four-year building schedule under traditional design-bid-build into just 30 months. The work included construction of a treatment plant, force main, trunk sewers, pump stations and administration and maintenance facilities. It was the largest treatment plant in the state to use the design-build delivery system.

Freelance writer Mary Lou Jay writes about business and technical developments in a variety of industries. She has been covering residential and commercial construction for more than 25 years.

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