|Artificial Wetlands/Remove Nitrates From Area Springs|
|Written by Marjorie Holt|
|Tuesday, March 2 2010|
Springs meeting offers solutions
By MARK SCOHIER
Dr. Robert Knight told about 32 scientists and concerned citizens attending the Fanning and Manatee Springs Working Group Thursday at Fanning Springs City Hall that artificial wetlands are great at removing pollutants from water.
“When you have lots of plants in wetlands,” he said, “you get very good removal of nitrogen, especially nitrates.”
And it’s nitrates that have become a big problem for Florida’s springs, including Manatee and Fanning. Fanning has the second highest rate in the state at about 5,000 parts per billion, according to Knight. That’s about 14 times higher than the 350 parts per billion considered safe.
Knight said artificial wetlands, consisting of a series of large cells loaded with nitrate reducing plants like cattails, could be constructed to deal with pollution from livestock and dairy farms, municipal wastewater and even private homes using septic tanks.
According to Knight, a 1,000-cow dairy farm would need a wetland that covered about 12 acres. A 1,000-person municipality wastewater treatment wetland would cover about 5 to 8 acres, and a single family home, using a septic tank, would need a small wetland taking up about 1,400 square feet.
Single family homes are not currently allowed to have their septics drain into small, privately owned wetlands, he added. But perhaps a number of homes could link up to a shared wetland.
Knight said the cost of creating a 5 to 8 acre wetland, the size a city like Fanning Springs would need, would cost about $300,000—about $300 per person.
One of the participants in the group asked Knight if any such designs had been taken on by any of the local dairies.
Knight said he talked to Alliance Dairies, the largest milk producer in the state, but said they don’t think it makes economic sense.
Alliance is meeting the standards set by the state, he said. But the state standards are not set high enough, he added.
Fanning Springs City Councilman Robert Kerr was at the meeting and told participants he was in favor of the city constructing an artificial wetland, a topic that has even more significance considering the city is now in the design phase of a new wastewater treatment facility.
Kerr said he would like to see the state contribute funds toward an artificial wetland to be used in conjunction with a wastewater facility.
“Why cant’ the state use Fanning as a pilot project?” he asked.
Knight said artificial wetlands are “less expensive to construct than traditional wastewater treatment facilities.” And they require little maintenance, often costing less than half of traditional facilities.
Existing retention ponds, which are often not very effective in Levy County due to the porous nature of the ground, could also be converted into wetlands, he said.
But Knight said nitrates aren’t the only problem. People need to find ways to reduce water consumption and minimize the use of nitrogen fertilizers, which are notorious for finding their way into the water table.
He said he has not been able to develop a wetland that can remove fertilizer.
“But it’s easy to reduce it,” he said. People can stop using it as much.
In other matters:
Manatee and Fanning Springs State Park Manager Sally Lieb was at the meeting and said the water levels at the parks are still high.
“I haven’t seen water like this in my career at these parks.”
Manatees are in the main swimming area, but the water’s dark, and it’s hard to see them, she said.
Fortunately, she added, it keeps people away from them.
Manatee Springs has also had a manatee show up around the beginning of January dragging a satellite beacon affixed to its tail, she said.
The animal was originally tagged at Wakulla Springs and has been tracked up to 30 miles off shore in the Gulf of Mexico, she said. Lieb said she spotted a second manatee, also wearing a tracking device, a few miles down river.
The park is also having a problem with Asian grass carp, according to Lieb.
“Some of these things are monsters,” she said holding her hand at about chin level to show the length of the fish.
The Florida Fish and Wildlife Conservation Commission came to the park on Feb. 3 and removed 28 of the fish, which compete with manatees for food in an environment already hit hard by the disappearance of native plants necessary for manatee survival, she said.
Some of the manatees in the park have also been seen floating on the surface, looking a bit bloated, she said.
She thought they may have been injured at first but later found out they were full of gas. Lieb said the gas is attributed to them eating too much algae, which, in recent years, has proliferated because of the water’s high nitrate levels.
Copyright www.chieflandcitizen.com. All rights reserved.
Print this article | Close this print window
|< Prev||Next >|