Underground Infrastructure - October 2023 - 33

ASSETMANAGEMENT
Working with Duke's 'Like Having
a Crystal Ball'
Corinna Hunt | Contributing Editor
When optimizing sewer and wastewater treatment systems, it
can be overwhelming to look at more than 100 miles of sewer
pipe funneling heavy flow during a rain event and wonder
where that excess flow is coming from.
" When somebody hands you a heat map and says, 'these
red pipes are taking on water,' it really makes it easy to go out
and determine where you need to spend your money for upgrading
the system, " said David Henson, environmental quality
superintendent for the Anniston Waterworks and Sewer
Board in Anniston, Alabama. " The value of knowing where to
look, it's like having a crystal ball. "
That map and that value are what Duke's provides. The
Illinois-based business has worked in the sewer industry for
a century, and its core service for the past several decades has
been root control, said Stuart Tillery, who has 24 years with
the company.
" Utilities hire us to treat their lines and kill the roots to prolong
the life of their assets, " he said.
Because tree roots search for nutrients in water, and sewer
pipes can develop condensation on their exterior, roots will
detect that condensation and advance along the pipe until
they can grow into a microscopic fissure.
Funnily enough, roots won't grow where there is excessive
groundwater because they'll drown there, but " it doesn't take
anything for a root to get into a pipe, " Tillery said. " Then when
they get in, they try to reach down for the water in there. It's
the ultimate nutrition for them, so they get real aggressive. "
One way to address the problem is for utilities to use a machine
to cut out the roots - a quick and easy way to ensure
removal. However, similar to cutting back a shrub, the plant
will grow back thicker and more quickly. This compounds the
necessary maintenance, Tillery said.
Herbicide
Duke's uses an herbicide, which tree roots draw up like water
until it kills them about 10 inches outside of the pipe, he
said. The company has only used two herbicides. In the early
2000s, Duke's hired an expert in pesticide herbicides to help
Duke's iTrackerTechnology.
find a product that worked better and faster, with less of an
environmental impact, than the product they'd been using.
The company has utilized this one ever since, with a two- to
three-year guarantee per treatment and a warrantied retreatment
rate of less than 1 percent.
" Our main objective was to have a very effective product
that did not harm the biology of the wastewater treatment
plant, " said Tillery. " The efficacy of the product has been more
than we could have hoped for. "
More recently, Duke's has expanded its offerings according
to the needs of the client.
" Probably in the last two to three years, we've recognized
there are other areas our clients are having issues with - most
UndergroundInfrastructure.com | OCTOBER 2023 33
http://www.UndergroundInfrastructure.com
Underground Infrastructure - October 2023

Table of Contents for the Digital Edition of Underground Infrastructure - October 2023
