District pilot project working to reduce phosphorus discharges to Doctors Lake watershed

Plastic pipes laying in a grid pattern

Doctors Lake Phosphorus Removal Pilot Project.

PALATKA, Fla., June 8, 2020 ― A full-scale demonstration project of the St. Johns River Water Management District to remove phosphorus from treated wastewater is now working to reduce the overabundance of nutrients that cause algal blooms in Doctors Lake in Clay County.

Plastic pipes laying in a grid pattern

Doctors Lake Phosphorus Removal Pilot Project.

After breaking ground in September 2019, the Doctors Lake Phosphorus Removal Pilot Project officially started June 5, 2020, removing dissolved phosphorus from treated wastewater from the Clay County Utility Authority’s Fleming Island Regional Wastewater Plant before it is reused for irrigation in the Doctors Lake watershed. The project will reduce the phosphorous concentration by 90% and will assist in furthering water quality improvements in Doctors Lake and the Lower St. Johns River Basin.

“Forward-thinking projects to reduce the overabundance of nutrients in Doctors Lake by reducing phosphorous in the watershed will play an important role in reducing the intensity and frequency of algal blooms,” said St. Johns River Water Management District Executive Director Dr. Ann Shortelle. “We thank Gov. DeSantis and our legislative delegation for their leadership and commitment to projects and funding to benefit the St. Johns River. We are excited to work again with CCUA and appreciate their continued willingness to partner on beneficial projects for the community.”

The one-year pilot project is funded through a 2018 $1.5 million legislative appropriation, spearheaded by Sen. Rob Bradley and Rep. Travis Cummings.

“I want to thank Dr. Shortelle, the Board of the St. Johns River Water Management District and Governor DeSantis for their commitment to this project,” said Sen. Bradley, of Fleming Island. “This project is critical to ending the dangerous toxic algae blooms we have seen in recent years in Doctors Lake. Rep. Cummings and I are pleased that the project moved forward quickly and are very proud to have been able to direct state resources to the community we love.”

“Since Sen. Bradley and I first secured the funding for this project in 2018 to combat harmful algal blooms in Doctors Lake, we have been eager to see how this new technology will improve the health of the lake,” said Rep. Cummings, also of Fleming Island. “I hope this partnership and dedicated commitment to improve water quality will continue, and our community will see real benefits from these efforts.”

“We look forward to seeing the results of this project over time,” said CCUA Executive Director Jeremy Johnston. “If successful, scaling and adapting this type of system may help reduce nutrients in many areas of the state. We greatly appreciate the partnership with SJRWMD to test new technologies in working toward sustaining our natural resources for future generations.”

The district has conducted water quality sampling on Doctors Lake since 1984. For 32 of the last 36 years, Doctors Lake has experienced repeated algal blooms. Because excessive nutrients help fuel algal blooms, the district uses water quality monitoring and science to focus its work on reducing nutrient sources before they can enter waterbodies.

In 2019, the district contracted with the Sustainable Water Investment Group (SWIG) to apply its state-of-the-art technology to the project site, where treated effluent is pumped and distributed over a vegetated filtration bed that uses engineered media to remove phosphorus. This media binds with phosphorus, removing it from the water. The phosphorus remains bound to the engineered media, so no byproduct is produced. The treated water from this innovative project is returned to the effluent stream and, ultimately, Doctors Lake and the lower St. Johns River watershed.