Members of the Peace River Basin Board and District staff recently set out on a fact-finding mission to the Orlando Wetlands Park. The group is exploring options on how to improve the water quality leaving Lake Hancock. The Wetlands Park is an example of one option under consideration.
Lake Hancock is in the headwaters of the Peace River watershed that extends 120 miles downriver to Charlotte Harbor, an estuary of national significance and a Surface Water Improvement and Management (SWIM) priority water body. Water quality leaving the 4,500-acre lake has been documented as a major source of poor water quality in the upper Peace River.
The water quality project is being completed in addition to the Lake Hancock Lake Level Modification Project. The Lake Hancock Projects are a critical part of the District’s recovery strategy for meeting the minimum flows in the upper Peace River, improving water quality in the Peace River and protecting Charlotte Harbor.
Treatment methods being considered include constructed wetlands, managed aquatic plant systems and chemical treatment followed by particle removal technologies such as sedimentation, filtration and dissolved air flotation.
“Although constructed wetlands are the most land-intensive technology being considered, they offer other benefits such as wildlife habitat and recreational opportunities,” said Janie Hagberg, senior professional engineer. “It’s hard to quantify those benefits, so we made the visit to the Orlando Wetlands Park to see them firsthand.”
If the District does choose to construct a wetlands treatment system similar to the Orlando Wetlands Park, the project will be located on part of the parcel of land formerly known as Old Florida Plantation. The District purchased the 3,500-acre parcel, which was planned for development, knowing it may serve as the site for the water quality improvement project.
The 1,220-acre Orlando Wetlands Park was built in the late 1980s and is one of the first large-scale wetlands built for wastewater treatment. Its primary purpose is to further treat wastewater discharged from Orlando’s Iron Bridge wastewater treatment plant, but it also serves as a public recreational site for bird watching, hiking and more.
“One of the striking differences between the various technologies is the beneficial value of creating wetlands,” said Mark Hammond, resource management director. “Other technologies don’t have that.”
“Do wetlands ever get to a point of saturation and cannot filter any more water?” asked Peace River Basin Board member Jim Hageman during the tour.
The answer is yes. As Hagberg explained to the group, that is why a wetlands treatment system for Lake Hancock would have to be large. That is also why the Orlando Wetlands Park was built to contain 17 separate wetland cells. Managers can close off one cell at a time to remove muck if it gets to the point of saturation.
While a wetlands system used to treat Lake Hancock would not be treating wastewater like the Orlando Wetlands Park, the treatment process would be the same. Cattails and bulrush would be the primary plants used to filter water.
“Cattails are the workhorse of wastewater treatment,” said Dr. Robert Knight of Wetlands Solutions, a consultant working with the District on the project. “They are very effective in removing nutrients.”
After District staff has explored all the treatment options, they will bring their findings back to the Peace River Basin Board and Governing Board so members can decide which treatment methods should be evaluated further. The next step in the evaluation is to construct actual pilot-scale demonstration projects of the top-ranked treatment methods. Staff hopes to recommend a pilot testing plan to the Boards in October. Pilot testing will be conducted for at least one year so that performance data is obtained during all seasons. Following the completion of the pilot phase, final recommendations will be made for the full-scale project. Construction is targeted for 2009 and 2010.