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Intern makes an impact
Student designs a device that could save thousands
Michael Ward with the Henry County Public Service Authority and Carlisle Senior Liz Lazaro are shown at the Axton water tank with the plans she worked on for a device that potentially could save Henry County tens of thousands of dollars. They were photographed with a wide-angle lens. (Bulletin photo by Mike Wray)
Sunday, August 24, 2014
By BEN R. WILLIAMS - Bulletin Staff Writer
A new device being used in the Axton water storage tank potentially could save Henry County tens of thousands of dollars.
Perhaps more impressive: The device was designed by a local high school student.
Liz Lazaro, 17, is the daughter of Deborah and Kenneth Lazaro of Martinsville. She is a senior at Carlisle School, and she also is taking engineering classes at the New College Institute through the Academy for Engineering and Technology dual enrollment program.
In early July, Lazaro began an internship at the Henry County Public Service Authority (PSA), working with Michael Ward, PSA director of regulatory compliance and technical applications.
Before the internship began, Lazaro said, she had no idea what it would entail. She wondered if she would find herself taking inventory, stacking boxes or just sitting behind a desk killing time.
As it turns out, she said, nothing could be further from the truth.
Ward said that during the internship, Lazaro helped out at Patriot Centre at Beaver Creek industrial park during the National Guard’s lot grading project, assisting with erosion and sediment control inspections. She also worked at the water plant doing testing and disinfection studies.
Her biggest project, however, came in early August, when Ward suggested that they put their heads together to try to address trihalomethane (THM) removal from the Axton water tank.
“THMs form when you have some amount of organics in your water,” Ward said. “All surface water has some amount of organics in it. When you add the chlorine to it, it forms these THMs as a byproduct.”
In some tests, Ward said, it has been shown that THMs can increase the risk of certain negative health effects. As a result, he said, the Environmental Protection Agency (EPA) has set a limit of 80 micrograms of THMs per liter of water.
The longer the chlorine in the water is exposed to organic compounds, Ward said, the more THMs form. This particularly becomes an issue in areas such as Axton, where there is a long distance between users and the water is held for longer periods of time.
Previously, Ward said, the county has flushed the water from the system when the THM count gets too high.
But a new device — custom-designed by Lazaro — could allow the PSA to filter THMs without wasting any water.
The way the device works, Ward said, is that a well-pump is installed at the bottom of the tank. This pumps the water up a pipe, which emerges from the top of the tank, and then re-enters the tank through a central vent.
When the water reaches the end of the pipe, Ward said, it passes through a corkscrew-shaped nozzle, which sprays the water back into the tank like a shower head. Exposure to air then strips the THMs from the water.
“Liz put a lot of work and thought into the best way to run (the pipe) up out of the hatch and then back in through the vent in the very center,” Ward said, “and how to do that and still be able to keep our seals required to keep the water safe and meet the health department requirements.”
Lazaro designed the apparatus using the 3D computer modeling program AutoCAD, she said.
“And she learned (AutoCAD) quick,” Ward added, laughing. “I’m still trying to get to that point.”
Ward and Lazaro also sought help from Dr. Robin Collins, a professor of civil engineering at the University of New Hampshire, who advised them on different calculations and on the shape of the nozzle used in the device.
The device was installed in the Axton tank on Thursday. However, the version currently in the tank is a smaller pilot version, Ward said.
After data is gathered, Ward and Lazaro will study it to determine how successful it was. If it successfully removed THMs from the water, they will build and install a larger version.
Ward believes that the county can do the engineering and labor on the full-size device in-house for between $10,000 and $15,000.
“If we were to hire somebody to do this, between hiring the engineering and a company to come in and put in their system, it could cost $200,000 for a tank of this size,” Ward said.
Lazaro and Ward said that if the device works, they would be happy to help other small communities engineer similar devices.
“This is really new territory for this district,” Ward said.
Lazaro almost has completed her summer internship hours, she said, but even though school has started back, she wants to continue working with the PSA.
Ward wants Lazaro to stick around, too. When the test data comes back from the pilot device, he wants her to help him do the analysis.
Lazaro has no uncertainty regarding her future career.
“I definitely want to go into civil engineering,” she said. “That’s what I’m fully decided on. Since I was probably in sixth grade, I’ve wanted to be a civil engineer.”
She hasn’t fully decided on a college, she said, but right now, her first choice is George Mason University.
“They have an amazing engineering program up there, and it’s a beautiful campus, too,” she said. “I think it would be a good option.”
Ward described Lazaro as hard-working, focused and a quick learner.
“It was our privilege to have her work with us for the summer,” Ward said. “She’s going to make a great engineer one day.”