Title

Missoula Wastewater Treatment Plant moves toward Zero Waste

Abstract

Since the construction of Missoula’s first waste water plant in 1962, the plant has undergone many upgrades. The primary treatment system was upgraded to secondary treatment in 1974. The plant’s capacity grew from 9 MGD in 1998 to 12 MGD by 2007. Over the past 30 years, loads to the river of nitrogen and phosphorus have been reduced by 70 and 85% respectively, even as the number of households and businesses served have increased by 14%. Surprisingly, despite the increasing number of people served by the plant, influent water to the plant has been dropping recently, thanks to water conservation efforts.

The most recent major upgrade to the Missoula WWTP involved the installation of a Biological Nutrient Removal system (using the Modified Johannesburg Process) in 2004. And starting in 2014, some of the effluent is being used to irrigate a hybrid poplar plantation. The city of Missoula is exploring using all of the effluent during the irrigation season.

A recent nutrient budget constructed for the WWTP showed that over 90% of the phosphorus entering the plant is captured as biosolids that is made into compost by Ekocompost. About 30% of the nitrogen is captured as biosolids, 20% enters the river, and almost 50% is apparently removed by denitrification.

While the plant and the nearby plantation greatly reduce nutrient loading to the river, the plant does use a lot of energy. The plant’s energy use accounted for about 36% of Missoula city government’s greenhouse gas emissions in 2008. The plant does capture about 50% on an annual basis of the methane generated by the digesters and uses it to heat digesters. The city is now studying capturing 100% of the methane to generate electricity to run pumps at the plant.

Start Date

24-4-2015 12:00 PM

End Date

24-4-2015 2:00 PM

Document Type

Poster

This document is currently not available here.

Share

COinS
 
Apr 24th, 12:00 PM Apr 24th, 2:00 PM

Missoula Wastewater Treatment Plant moves toward Zero Waste

Since the construction of Missoula’s first waste water plant in 1962, the plant has undergone many upgrades. The primary treatment system was upgraded to secondary treatment in 1974. The plant’s capacity grew from 9 MGD in 1998 to 12 MGD by 2007. Over the past 30 years, loads to the river of nitrogen and phosphorus have been reduced by 70 and 85% respectively, even as the number of households and businesses served have increased by 14%. Surprisingly, despite the increasing number of people served by the plant, influent water to the plant has been dropping recently, thanks to water conservation efforts.

The most recent major upgrade to the Missoula WWTP involved the installation of a Biological Nutrient Removal system (using the Modified Johannesburg Process) in 2004. And starting in 2014, some of the effluent is being used to irrigate a hybrid poplar plantation. The city of Missoula is exploring using all of the effluent during the irrigation season.

A recent nutrient budget constructed for the WWTP showed that over 90% of the phosphorus entering the plant is captured as biosolids that is made into compost by Ekocompost. About 30% of the nitrogen is captured as biosolids, 20% enters the river, and almost 50% is apparently removed by denitrification.

While the plant and the nearby plantation greatly reduce nutrient loading to the river, the plant does use a lot of energy. The plant’s energy use accounted for about 36% of Missoula city government’s greenhouse gas emissions in 2008. The plant does capture about 50% on an annual basis of the methane generated by the digesters and uses it to heat digesters. The city is now studying capturing 100% of the methane to generate electricity to run pumps at the plant.