HomeMy WebLinkAboutItem 03 Metropolitan Wastewater Management Commission Project RecognitionApril 15, 2013
Springfield Upbeat
EWEB/MWMC presentation before the Springfield City Council
At the regional Water Pollution Control Facility (wastewater treatment plant) the secondary
treatment process is the highest consumer of energy – more than half of the total used at the
plant. That’s because huge blowers are needed to provide air to eight aeration basins. Thirty
years ago, the treatment plant installed six 1,000-horsepower constant-speed turbo blowers that
throttle inlet air to reduce output, making them inefficient unless they are running at full capacity.
Over the years, major process improvements such as fine bubble diffusers have resulted in a
significant reduction in air demand in the secondary treatment process. As a result, one of the
original blowers recently was replaced with a new high efficiency, single-stage blower. This
blower uses frictionless air bearings and water cooled high-speed variable frequency drives that
significantly reduce the amount of energy required for operation. In addition to being more
efficient, it provides a broader turn-down range of operation to better match actual process
requirements.
The design and construction of the new blower project was originally estimated to cost $1.4
million; however, staff performed the majority of the work internally and was able to reduce the
initial capital cost by 35%. Annual operating energy savings are estimated to be 2 million
kilowatt hours, which is enough energy to power 100 homes for a year.
The MWMC partnered with Bonneville Power Authority and Eugene Water and Electric
Board on this project. The project exemplifies how a single investment can provide both
energy efficiency and demand response flexibility. The demand-response goal was to
demonstrate that the treatment plant can adjust its energy demands to increase load when there
is extra capacity on the grid, and decrease load during peak periods, capacity constraints,
grid emergencies, or during periods when renewable resources experience intermittency.
Despite a tight timeline that required a lot of work to be done in December, the installation of the
new blower, inlet and discharge piping, transformer, switchboard, and active harmonic filter
were completed as planned. Startup of the blower took place on January 14, 2013.