Project Description

Polk County North Central Landfill and SMMRL began collaborating on a way to treat the landfill’s leachate in early 2019. The result of this collaboration was to design and build a Constructed Wetland Leachate Treatment System (CWLTS). SMMRL researchers worked on the design for a full-scale system and constructed pilot-scale versions of vertical flow wetland cells to guide future construction and operations of the CWLTS. The result of this work is a completed, full-scale system that includes an aeration pond, sedimentation pond, four vertical flow wetland cells, and a free water surface wetland cell. The system began operations in February 2025 and is designed to remove ammonia, nitrate, iron, and trace metals, amongst other constituents present in leachate.

Highlights

Lead Researchers:

• Dreyton Lott, PhD – djlott@ufl.edu
• Cassandra Collins – cassandracollins@ufl.edu

Publications

• https://pubs.acs.org/doi/abs/10.1021/acsestengg.2c00269
• https://www.sciencedirect.com/science/article/pii/S004565352401302X

• https://www.sciencedirect.com/science/article/pii/S0956053X23002209

News Coverage

• https://www.youtube.com/watch?v=Y4YV8Cbl8-0https://www.polk-county.net/news/polk-county-celebrates-opening-of-constructed-wetlands-leachate-treatment-system-at-north-central-landfill/https://news.ufl.edu/2024/09/polk-county-leachate-treatment-facility/https://www.theledger.com/story/news/local/2024/09/17/polk-county-to-sell-landfill-gas-methane-and-treat-leachate-on-sitepolk-county-recycling-land-fill-m/75141486007/?gnt-cfr=1&gca-cat=p&gca-uir=true&gca-epti=undefined&gca-ft=0&gca-ds=sophi

• https://www.polk-county.net/polk-county-solid-waste-divisions-new-green-projects/

System Overview

• This is where we would put link to the page where you could click through the system and look at the photos from the PowerPoint file on the M: Drive.

Project Timeline

• 2019: Polk County Solid Waste and the University of Florida (UF) Sustainable Materials Management Research Lab (SMMRL) agree to examine alternative leachate disposal methods, with the development of a constructed wetlands-based system becoming the focus.
• 2020: Preliminary design work is undertaken by researchers at UF SMMRL to determine what the system will look like overall.
• 2021: Pilot-scale testing of vertical flow wetland cells at UF SMMRL begins, examining the treatment of landfill leachate collected on-site and transported back to the lab to determine optimal loading schedule. Design work continues and a solid waste permit modification from the Florida Department of Environmental Protection is obtained for the system.
• 2022: A second trial of pilot scale testing occurs at UF SMMRL utilizing two stages of vertical flow wetland cells and an industrial wastewater permit for the system is obtained from the Florida Department of Environmental Protection. System design continues with the assistance of Jones Edmunds until it is ready to go out to bid. The project is approved by the County and goes out to bid.
• 2023: Construction begins in June. A third trial of pilot scale testing occurs at UF SMMRL in the examination of future modifications to the system that may enhance treatment.
• 2024: Construction continues as preparations are made for the beginning of operations. The residence time within the free water surface wetland cell is measured from August to October utilizing Rhodamine WT.
• 2025: Construction is complete and the system begins operations on February 17^th. An average of 3,000 gpd of leachate are sent to the system in the beginning, and by the end of the year the average flow into the system is approximately 17,000 gpd of leachate into the aeration pond. Researchers from UF SMMRL spend the year monitoring, documenting, and studying the system’s performance as operations are underway.
  
• 2026 and beyond: Polk County Solid Waste and UF SMMRL look to increase the flow of leachate into the system and continue monitoring its performance into the future for years to come.