Most people don’t know where their water goes with the flush of the toilet. Not so with the kids at Tyner elementary school in Jackson County. That is because in cooperation with the environmental group Eastern Kentucky PRIDE, the U.S. Army Corp of Engineers, Jackson County Schools, and CDP Engineers, a natural wetlands system was constructed to treat the school’s wastewater. These systems, which utilize a series of shallow 2-12 inch-deep ponds and variety of carefully selected native riparian plants, utilize nature’s physical, chemical, and biological processes to treat wastewater. The vegetation obstructs the flow of water, allowing a lot of suspended and dissolved material to settle out. Bacteria, which aid in filtration, cling to the plants, help to absorb and transform the wastewater particulate, and naturally oxygenate the water.
Acorus Calumus, commonly known as Sweet Flag, is the same plant that calamine lotion is made out of. Its sweet cinnamon-like fragrance comes from the leaves and roots of this tall sedge, prized for its antimicrobial and insecticidal activities. Sweetflag is just one of the many aquatic plants gracing each of the three ponds of the water treatment system. The plants are staggered to provide a variety of heights and colors when plants like the Blue Flag Iris, Rose Mallow, Cardinal Flower, and Joe Pie weed bloom.
Designed to handle 10,000 gallons per day, Tyner Elementary School’s previous treatment system was overstressed, sometimes treating up to 13,000 gallons at a time. For the Laurel Fork of Rockcastle River, where the schools waste water is released, this was bad news, as frequently the discharged water tested high in fecal coliform counts, an environmental disaster that results in large algae blooms which use up all the oxygen in the water and make it difficult for stream-life to flourish (this is also a huge problem with agricultural fertilizer run-off).
Typically the construction costs for these systems range anywhere from one-tenth to one half the cost of conventional treatment, often produce cleaner water than conventional systems, and require very little maintenance. For Tyner Elementary, the surrounding soil’s high clay content provided the perfect natural barrier for the system. With far fewer mechanical parts, as well as reduced maintenance time, costs savings of between $12,875 to $13,250 dollars per year are expected. It will also result in decreased energy use.
But the benefits of Tyner’s new wastewater treatment system aren’t purely logistical or financial. To understand the system’s environmental contribution, we must revisit the landscape of Kentucky’s past. In the 1600s more than 220 million acres of wetlands are thought to have existed in the lower 48 states. By the mid-1980′s, the number of wetland acres nation-wide had dropped by nearly half that, to 103 million acres. The reasons range from increased numbers of levees, which prevent regular flooding along rivers such as the Mississippi, to increased development. In Kentucky, most wetland loss has resulted from the development of agricultural fields; the years of sediment accumulation these ecosystems provide contributing a rich source of nutrients for supporting agriculture. Kentucky stands out as one of seven states that has experienced an even higher loss in wetlands – according to a report by the Environmental Protection Agency, over 80% of our wetland acres are gone.
According to the EPA, wetlands are second only to the ocean in the number of organisms inhabiting them. A third of the United States’ threatened and endangered species are found in wetlands, and at least half inhabit wetlands at some point in their lifecycles. One thing is clear, protecting these unique habitats is crucial if we want ensure biodiversity.
In addition to habitat, wetlands also provide a means for recharging our aquifers, those deposits deep underground where we draw our well water, a fast disappearing resource. In Kentucky, a state with a relatively high percentage of ground-water recharge due to the large prevalence of caves and disappearing streams, the problem is making sure that the surface water isn’t contaminated.
The problem becomes where to re-install these wetlands, and the answer is almost always going to be on private land. US Forest Service wildlife biologist Tom Biebighauser notes that schools offer a unique opportunity for these projects. Not only do schools often have large parcels of land, but the installation of wetlands offers great outdoor classrooms for studying ecology and science concepts. Biebighauser has traveled the states overseeing several wetland installation projects, including at Kirksville Elementary, EKU, and one at Glen Marshall elementary school.
“It works” says Biebighauser, speaking of the multiple benefits of school ground wetland ecosystems. “Teachers know that if you can get students outside, into a restored stream or wetland, they are going to remember what they are taught.” Not only that, but the systems create habitat for reptiles and amphibians, water fowl, and fish, right there where students can study them.