Aquifer Recharge at Flatford Swamp

This project will investigate the recharging of excess surface water, treated to primary drinking water standards, into the Upper Floridan aquifer more than 1,000 feet below the land’s surface. The recharged water will help improve groundwater levels and reduce the rate of saltwater intrusion from the Gulf of Mexico in the SWUCA’s Most Impacted Area.

SWUCA Recovery and Natural System Improvement

In 2017, the District conducted a feasibility study at Flatford Swamp in Manatee County that evaluated an aquifer recharge project using up to two million gallons per day (mgd) of excess surface water draining into Flatford Swamp.

The fully operational Flatford Swamp project (future build-out of 3 to 4 wells) may help recover groundwater levels by recharging up to 10 mgd in the Most Impacted Area of the SWUCA and could reduce the rate of saltwater intrusion. Another benefit of removing excess water from the swamp is that it has the potential to help trend the swamp back toward its historic, natural hydrologic period and vegetation patterns.

Staff plans to implement a step-by-step analysis conducting additional data collection, monitoring, and integrated modeling to ensure the project concept is thoroughly evaluated.

The first test well site will provide the District with operational testing data and insight into the potential future benefit of additional well sites at Flatford Swamp. The data we obtain will be analyzed and presented to our Governing Board for their authorization to apply for an operational permit.

Implementation and continuation of the recharge project is contingent upon assuring that it is safe for the water resources and beneficial for groundwater levels.

Project Details

In January 2017, the District held a public meeting prior to FDEP’s issuance of a permit. In April 2017, the District’s Governing Board unanimously approved the project. During late 2017 and early 2018, staff worked on sampling the source water as well as retaining a consultant engineer and a driller.

During the stakeholder engagement process, the District received inquiries from the agricultural community about water quality. In coordination with the UF/IFAS Plant Diagnostic Center, District staff confirmed that there was no presence of Phytophthora, a mold that could impact certain agricultural crops, in the surface water. Testing continued twice a year for approximately four years. Considering continuous negative results, phytophthora sampling stopped at the end of 2021.  

Rowe Drilling conducted drilling on all four wells at the Flatford site. Drilling of the final well was completed in April of 2019. Jones Edmonds completed the design of the diversion infrastructure and TLC Diversified began construction in August 2020

The majority of the construction of the diversion infrastructure was completed in September 2021. This included the installation of the borehole control valve, and construction of the intake structure, recharge building, recharge pump, and chemical feed shed. Development of the FDEP UIC permit renewal request is underway. Following May 2021 permitting discussions with FDEP, staff is implementing a new treatment concept that includes the use of chloramines for disinfection and Sodium Bisulfite (SBS) for dissolved oxygen removal. Construction of this new system is completed.

The operational testing phase will begin in the fall of 2022. Testing will begin when the site is operational and will include close observation of water quality at the monitoring wells.

A wetland monitoring project is also being conducted by District staff to track any changes in hydrology and vegetation that may be caused by the recharge well operation.   

The District will continue to work with key stakeholders and other interested parties. Please contact the project manager with any questions.

Project Schedule

Step 1: Desktop and modeling evaluation. Permit test well. – Complete

Step 2: Drill test and monitor wells. Collect aquifer characteristics and water quality. – Complete

Step 3: Conduct pilot study and construct diversion infrastructure. – Complete

Step 4: Construct disinfection system. – Complete

Step 5: Begin recharge surface water test. Continue appropriate testing. – Late 2022

Step 6: Evaluate all testing results. – 2023

Project Updates

August

  • Finish equipment testing- Borehole control valve testing scheduled for August 16-17.
  • Complete requisite testing for FDEP.

 

September

  • Maintaining and preparing site for operation.
  • Completed final baseline wetland monitoring and will begin finalizing comprehensive report.
  • Continue staff development on data collection.

Projected October

  • Finalize equipment repairs.
  • Finalize procurement of disinfection chemicals.
  • Obtain approval from DEP to begin operation.
  • Begin operational testing.
  • Monitor site, equipment, and water quality.