Last week, more than a dozen college students, walked slowly back and forth in huge sunken sand pits at the Bradford Sanitary Authority planting reeds.
The new reed beds will help the authority process sewage with less energy and money. In an adjacent sand pit, reeds that had been planted by the environmental studies students from the University of Pittsburgh at Bradford last month, already stood a couple of feet high.
Until recently, the sand pits had been part of the sewage treatment plant’s system for reducing ammonia in its treated wastewater before it is returned to the Tunungwant Creek. As part of major upgrades at the plant, new processes are able to do the same thing more quickly and replace sand pit ammonia-removal system.
Jack Rae, the authority’s consulting engineer from Gannett Fleming, said that he realized the pits might work for the construction of a reed bed and contacted Scott Davis of the Constructed Wetlands Group.
Davis explained that reed beds dry out the sludge produced by the wastewater treatment process more efficiently than mechanical means. The sludge will be sprayed over the four acres of reed beds. Nourished by the sludge, the reeds will grow quickly to 10 to 12 feet high. The reeds’ roots will absorb water, and the plants will release the moisture into the atmosphere through small pores in a process called evapotranspiration.
Additionally, the reeds support an active microflora (“bugs”) within their dense root system that continually break down the sludge, resulting in a well-degraded soil like compost at the end of the 8-to-10 year cycle.
The reeds should reach maturity by November. “This will look like a corn field on steroids,” said Rick Brocius, executive director of the authority.
The reeds will remove so much of the water from the sludge that just a thin, crusty layer will remain. In the winter, the reeds will die back and be burned away, but the sludge can continue to be applied during the freeze-thaw cycle. In the spring, the reeds return and the cycle continues.
The beds essentially eliminate the need to truck sludge to the landfill, Davis explained. The authority can keep applying layers of sludge to the four acres of reed beds at Bradford for what Davis estimates will be 10 years. At that point, one bed can be emptied each year and reeds replanted.
In addition to removing water from the sludge, the reeds are also able to eliminate some harmful substances, such as heavy metals. It is possible, Davis said, that the remaining solids might even have a further beneficial use, such as being applied as topsoil to mine drainage or farming.
Davis suggested using college students with an interest in the environment to plant the reeds.
Emily Reams, an environmental studies major from Bradford, was one of them. Reed bed planting is just one of the environmental projects she is working on this summer. She is also the sustainability coordinator intern for Pitt-Bradford.
Reams said she was concerned that the genus of reed being used, phragmites, is an invasive species in Pennsylvania. She said that Constructed Wetlands sent pamphlets explaining that phragmites spreads through rhizomes, lateral growing stems that put out roots underground. Because it does not spread through seed easily, there is little risk that the reeds would take root outside the constructed reed bed.
Davis said his group would continue to monitor the beds and the creek for signs that the reeds are spreading.
Satisfied with the answers, Reams supports the project. “Here we’re treating the bio solids, and it’s a low-energy system for a high-value return.”
Lester Perry was a sociology major from Philadelphia planting reeds. He was interested in the project because he has taken some classes in plants and sociology. Perry grew up in Liberia, where he said natural methods are preferred. “We don’t use a lot of chemicals and pesticides to grow,” he said.
“I thought this was a cool idea, and I’m happy to help the process.”
Dr. Stephen Robar, director of the environmental studies program, was pleased that students had a chance to take part in the installation of a green industrial system and make a little money, too.
“It’s invaluable for students to see how an environmental management project like this works,” he said.
Brocius said he would welcome Pitt-Bradford professors and students back to study the reed beds as well since they are known to attract certain insects, such as aphids, and nesting water birds.