Page 13 - Nov-Dec18

One of the largest energy-consuming operations in most cities daily lives to making sure we have clean
is often a missed opportunity: drinking water and wastewater water, but the operators and managers
in this program dedicate themselves
treatment systems. Nationally, three to four percent of all to finding new ways to save their
electricity produced is used for treating wastewater and communities money, while improving
their environmental outcomes.”
distributing drinking water.
The success of TDEC’s Wastewater
second digester from constant operation the maximum savings we can during Optimization Program has inspired
to only six hours per day. Beginning operation.” similar programs in Alabama and
in April 2017, the plant staff started Kentucky, while other states are
manually adjusting the aerator operation Another WWTP invited to participate exploring doing the same. One of the
schedule as a part of routine duties. This was the Lawrenceburg WWTP, which key lessons learned is the need for
single change reduced electricity use by was running two 40-HP blowers for continuing engagement by TDEC with
14 percent, and saved over 7,000 kWh 16 hours a day. Instead, the team the participating wastewater systems. To
per month despite a 15-percent increase recommended only running one 40- foster success, TDEC and the Partnership
in wastewater loading. Staff expects to HP blower for six to eight hours a encourage implementation and how
use some of the savings to purchase and day. In August 2018, Lawrenceburg to maintain optimization measures,
install timers in the near future. The replaced their fine bubble diffusers in provide technical assistance in process
timers will automate this change and the sequencing batch reactors, which optimization and data tracking, all the
manage further reductions. needed changing. These no-to-low-cost while encouraging support from the
measures account for an average decrease town leaders and management for the
Through these operational changes, in electricity consumption of 29,000 kWh treatment plant staff. TDEC is exploring
the Carthage WWTP has seen cost monthly (or ~348,000 kWh annually) how to integrate these efforts into
savings in their electric bill as well. “We and an estimated $1,700 reduction wastewater operator and field inspector
have averaged saving $401 a month in monthly electricity bills (about training through the development of
(on a $4,181 monthly bill),” says Ricky $20,000 annually), all while absorbing electronic training resources. Meanwhile,
Brown with Carthage WWTP. “This a 14-percent increase in flow and water and wastewater systems may
was accomplished by reducing the biochemical oxygen demand removal. still receive assistance through Brett
amount of time we run our blowers on Ben Bolton, TDEC Energy Programs Ward at MTAS or through Dr. Glenn
the final digester. We are in the process Administrator, has managed the DOE- Cunningham, Director of the DOE-
of reducing the time even more. We funded project since starting with funded Industrial Assessment Center at
will continue to monitor odor control TDEC in 2015 and commented, “These Tennessee Technological University.
and permit levels until we achieve wastewater operators dedicate their
NOTICE: This material is based upon work
supported by the U.S. Department of Energy,
Office of Energy Efficiency and Renewable Energy
(EERE), under Award Number DE-EE0007226.

ABOVE: The day after the project team’s site visit, Carthage Wastewater
Treatment Plant operators Steve Key (left) and Ricky Brown (right) began
implementing the recommendations. Their dedication led to a 19-percent
cost savings ($$/MG treated) with no capital investment. TOP LEFT: During a
typical site visit, Bob Freeman, P.E., Softpath Environmental and retired from
EPA Region 4 (left), will take real time water quality measurements while Larry
Moore, P.E. Ph.D., Professor Emeritus, Civil Engineering, University of Memphis
(right) will discuss operations with plant staff (center). BOTTOM LEFT: Dr. Larry
Moore, University of Memphis, (center) and Brett Ward, MTAS (right), discuss
optimization opportunities with wastewater staff in Columbia, TN.

View online at tnpublicworks.com 13