VT College of Science Magazine Annual 2014 | Page 22

Science, Engineering

Collaboration Helps To
Provide Safe Drinking Water

E

ach day, the Western Virginia Water Authority provides
water service to more than 158,000 people through a
system of reservoirs and treatment facilities.
Each day for more than 10 years, Virginia Tech scientists and students have used an environmentally friendly approach to help to
make sure the water is safe.
Cayelan Carey is an assistant professor of biological sciences whose
research interests reside in freshwater and ecosystem ecology. Carey,
who received her bachelor’s degree from Dartmouth and her doctoral degree from Cornell, joined the biological sciences faculty in 2013
largely because of the strength of freshwater research at Virginia
Tech, including a project at the Falling Creek Reservoir in Roanoke,
Virginia.
In winter 2012, John Little, the Charles E. Via Jr. Professor of Civil
and Environmental Engineering, invited Carey to collaborate on a
project to improve Falling Creek’s water quality. At that time, much
of the project’s expertise was focused on the engineering necessary to install and operate of a new system to reduce algae. Carey
said her research in controlling algae and the opportunity to use
a cutting-edge engineering system made joining the Falling Creek
research team an easy decision, a year before she arrived at Virginia
Tech.
Working with a team of students at the smallest of the Western Virginia Water Authority’s reservoirs, the group’s goal was to test the
new system to keep algae out of the drinking water supply.
The location of the reservoir, while picturesque, presents a number
of issues that make it an ideal candidate for algae blooms.
“The reservoir is small and shallow, it’s in a valley, and it has to contend with the effects of wind,” said Jamie Morris, water production
manager with the water authority.
In short, it’s not the best place to be.
It’s also at the end of the line. Falling Creek is fed by streams from
much larger reservoirs that bring with them phosphorus. This phos-

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phorus can be stored in the lake sediments and is largely responsible for creating algae blooms.
To help with the issue, the team installed the new water oxygenation system in 2012. Carey and her team have been testing and
modifying it throughout 2013. The side-stream saturation system
was developed to maintain oxygen at the sediment level by removing water to a small, land-based facility and injecting it with oxygen
under pressure before returning it to the same depth in the reservoir. The oxygen helps keep phosphorus locked in the sediments,
preventing algal blooms.
The system has never been deployed successfully in a shallow lake,
so the researchers are gathering water-quality data while testing
new equipment that could provide major improvements to water
quality in other lakes.
“The testing we did in 2013 went very well,” Carey said. “When we
completed our analysis in the fall it confirmed the oxygenation
system in Falling Creek was successful in preventing iron (Fe) and
manganese (Mn) release from the lake sediments into the water
column. Our 2013 testing also showed that iron and manganese

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COLLEGE OF SCIENCE ANNUAL