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Last Updated: 03/25/2005
The Rockbridge Report is produced
under the supervision of the Dept. of Journalism and Mass Communications
at Washington and Lee University.
Reporting supervisors: Prof. Doug Cumming
Technical supervisor:
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Boxerwood waste treatment
system provides educational and environmental value
By Michael Patterson The stewards at Boxerwood Gardens, a 31-acre nature center and arboretum located outside Lexington, have discovered an unusual tool to teach local students about “ecosystem interaction” and “environmental stewardship.” Human waste. The Nature-Emulating Waste Treatment System (NEWTS) breaks down wastewater from Boxerwood’s toilets, showers and sinks using an ecologically friendly and aesthetically pleasing variety of micro-organisms, plants and animals. “NEWTS cleans waste in a way that lets everything in nature do what it likes to do,” said Hunter Mohring, Boxerwood’s executive steward. The $48,000 NEWTS system is modeled after the “Living Machine,” an innovative wastewater treatment system designed by John Todd, an ecology professor at the University of Vermont. Instead of filtering wastewater through underground layers of sand and clay like typical septic systems, Living Machines employ living organisms to snatch up excess nutrients and bacteria. The result is a completely enclosed treatment system that supports its own mini-ecosystem. NEWTS was designed specifically for Boxerwood Gardens, to serve as an educational tool and as a much-needed wastewater treatment system. Until last August, when NEWTS was plugged in, Boxerwood relied on an outdated septic system that, like many in Rockbridge County, was probably polluting the nearby groundwater. The unique underground rock structure in much of the valley, called karst geology, makes it easy for septic water to reach groundwater reserves largely unfiltered. The karst structure was created by acidic rainwater, which has eaten holes through the county’s soft limestone bedrock over millions of years. When underground septic tanks distribute wastewater near these holes, it can flow unfiltered into groundwater reserves and contaminate drinking water in a matter of minutes. “In some areas, you’ve got a septic field, and another hundred feet away, you’ve got your neighbor’s well, so it can be a problem,” said Washington and Lee geology professor Elizabeth Knapp. Instead of releasing wastewater directly into the ground from its septic tank, NEWTS pumps Boxerwood’s excess water through a series of re-circulating sand filters. The above ground filters provide an ideal home for aerobic bacteria, which cling to the sediment and feed on the water’s excess nutrients and other waste. “They love it,” said Mohring, referring to the bacteria, which she and Garden Steward Karen Bailey nurture like microscopic pets. Each drop of wastewater is pumped through the filters several times before it flows into a “constructed wetland” enclosed in a large greenhouse. The wetland supports a variety of plants--cat-tails, ginger, reeds, banana trees, algae, mosses, garden impatiens--that grow exclusively from nutrients gathered from the wastewater. Any excess water that the plants don’t absorb feeds a miniature pond in the greenhouse, which is home to several fish, frogs and of course, newts. The system is highly efficient, uses less electricity than it takes to power a 100-watt light bulb. And according to Mohring, maintenance costs are almost non-existent. “Once it’s up and running, it’s very easy to manage,” she said. NEWTS is a cost-effective solution to Boxerwood’s wastewater problems, but for Mohring, the system is even more valuable for its educational benefits. Elementary and middle school students from Lexington, Rockbridge County and Buena Vista learn about human roles in the ecosystem, and the importance of watershed management through the NEWTS system. NEWTS has even attracted the attention of W&L faculty. Carrie Reinhardt, an environmental studies professor, recently took her class on a field trip to Boxerwood to learn about NEWTS. “NEWTS shows us that there are alternatives to the way we deal with our waste, and to the way we go about our daily lives,” said Reinhardt. Could Living Machines like NEWTS be used by individual homeowners? By an entire municipality? It depends. Mohring estimates that the average homeowner could install a NEWTS-like system in two months, at a cost of around $10,000-assuming he has enough room on his land. The average septic system in Rockbridge County costs between $4,000 to $6,500, according to Tom Beebe from Beebe Construction Inc. in Lexington. Reinhardt thinks that space and restraints and the lack of adequate infrastructure would prevent many homeowners in Lexington from installing their own NEWTS, but she said they could be applicable to rural areas. When asked about Living Machines, Joe Milo, manager of the wastewater treatment plant in Lexington, said he was unfamiliar with the method. “I’m the wrong guy to ask about that,” he said. Mohring said that most public wastewater treatment providers either don’t know about the relatively new technology or are reluctant to adopt it. She said that the learning curve can be high for both engineers and water service officials. “We’re on the cutting edge as far as NEWTS is concerned, kind of like the computer before all the bugs were worked out,” said Mohring. The NEWTS system is only large enough to process 1,000 gallons of wastewater per day (enough to accommodate four to five households), but larger Living Machine systems are starting to appear around the United States. At Ethel M Chocolates Co. in Las Vegas, a Living Machine cleans 32,000 gallons of highly concentrated wastewater every day. A Living Machine in Burlington, Vt. treats 80,000 gallons of municipal wastewater per day, and Bayer Chemical Co. uses Living Machines to clean wastewater from five of their chemical labs in Beaumont, Texas. Jim Laurie, the chemist and engineer who designed the treatment systems in Texas and Vermont, thinks rising energy prices will eventually force municipalities to take a closer look at Living Machines. “I think it can work [on a larger scale]," he said. "I just don’t know where or when.” |
How does NEWTS work?
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