Missoula Hyrbrid Poplar Irrigation Expansion Project
Award Winner: 2015 ACEC American Council of Engineering Companies of Montana Excellence Award, Small Projects Category and 2013-2014 Sustainable Business Council’s Sustainable New Venture of the Year Award.
After a successful pilot project that began in 2009—where 1.6 acres of hybrid poplar trees were planted and fed with discharge from the Missoula Wastewater Treatment Plant—the City decided to scale up its investment and expanded the project in 2012 and again in 2013 to grow 96,000 trees a half mile west of the treatment plant. City officials, along with their team of consultants, predict that once the trees reached maturity in 2027, the treatment plant would divert an estimated 15 percent of its effluent, or 1.5 million gallons a day, to the plantation, thus significantly reducing the phosphorous and nitrogen load discharged to the Clark Fork River.
The $1.375M project is 10 to 20 times more cost-effective than installing more equipment to meet tightening environmental standards for the levels of nutrients going into the river. It also is expected to generate $2M in revenue from the 2027 harvest.
The Morrison-Maierle team worked with the stakeholders to lease tree farm property, calculate nutrient uptake and allowable irrigation flows to obtain a permit for the project from the Montana Department of Environmental Quality (DEQ), design a pumping and pipe system to deliver the effluent, and help with startup of the system.
Morrison-Maierle was the engineer of record for this project. The firm prepared calculations for submittal to DEQ documenting soil conditions, distance to groundwater, uptake rates for hybrid poplar trees, and produced a maximum watering schedule for the trees as they matured over their 20-25 year life span. Morrison-Maierle also produced bid documents for the pump station, flow meter, and piping to transport the water from the treatment plant to the poplar plantation filtration station.