Known industry-wide as engineering’s “Academy Awards”— the competition concludes with a gala celebrating U.S. engineering firms for projects demonstrating exceptional innovation, complexity, achievement, and value. Thirty-six projects were honored before an audience of industry professionals, government officials, and dignitaries at the April 17 event in Washington, D.C.
The Grand Award, one of only 16 given annually, was presented to the City of Boise and Brown and Caldwell for the Dixie Drain Phosphorus Removal Facility. Grand Awards recognize engineering accomplishments that contribute to the advancement of engineering and enhances the economic and social welfare of the public. This year’s competition yielded hundreds of entries as a distinguished panel of judges selected the nation’s best projects to receive Grand Awards.
Treating 130 million gallons of water daily, the Dixie Drain Phosphorus Removal Facility is the first of its kind in the U.S. and considered a model facility in watershed-based approaches to meeting total maximum daily load limits—the pollutant load a water body can receive without violating U.S. Clean Water Act standards.
To reduce the impact of excess phosphorous entering the Boise River, regulations required a 98% phosphorus discharge reduction from Boise’s water renewal facilities. As the city makes improvements at its facilities to remove 93% of the phosphorus, upgrades to eliminate the remaining five percent would require costly modifications. Subsequently, the city implemented a pioneering pollutant offset approach via the Dixie Drain Phosphorus Removal Facility project.
Located 34 miles downstream from Boise’s primary water renewal facilities, the Dixie Drain Phosphorus Removal Facility collects ground and surface water from agricultural operations in the lower Boise River watershed, removing 140 lbs of phosphorus per day (10 tons annually). For every pound uncollected at a Boise upstream facility, 1.5 lbs are removed downstream at the Dixie Drain Phosphorus Removal Facility, a more cost-effective solution with significantly greater environmental benefits to the Boise and Snake rivers. This non-point phosphorus removal offset is written directly into the city’s National Pollutant Discharge Elimination System permit.
The city hired Brown and Caldwell, an environmental engineering and construction firm, to conceptualize, pilot, and design the $21 million facility, which this year received two regional ACEC awards—ACEC-Idaho’s Grand Concept Award and first place in their water and stormwater category.
According to the city’s Public Works Director Steve Burgos, this groundbreaking yet commonsense approach is a model for regions facing nutrient removal challenges and budget constraints.
“This innovative solution eliminated the need to implement more capital-intensive modifications and at the same time remove 50 percent more phosphorus that would have been otherwise untouched,” Burgos said. “The Dixie Drain Phosphorus Removal Facility project is setting a national precedent for addressing water quality issues more effectively and affordably.”
Brown and Caldwell
www.brownandcaldwell.com