"FIPR’s tax money has been well spent on this research, but more needs to be done to show the long-term impact of treating soils with phosphate to fix lead. There is a great interest in the work, but for the method to be accepted by regulators long-term data are necessary.

Lena Q. Ma, Professor
Soil and Water Science Department
Institute of Food and Agricultural Sciences
University of Florida

Lead that makes its way into ground and surface water from contaminated sites is a heavy metal of great environmental concern to the U.S. Environmental Protection Agency (EPA) and the Florida Department of Environmental Protection (DEP). There are hundreds of sites in Florida that are contaminated with lead. Lead contamination from abandoned shooting ranges, for instance, has become a concern in the state. Cleaning up such sites is not easy. High costs and lack of effective remediation technology increase the probability that these contaminated sites will remain contaminated and continue to pose environmental and health concerns. A FIPR study shows that phosphate could provide a cost-effective way to remediate soils contaminated with lead.

Phosphate effectively immobilizes lead in soil, according to a recently completed FIPR-funded study. This means that the lead does not leach into the ground or surface water and plants cannot take it up through their roots. The study was conducted in Jacksonville on a site that during the past several decades had been polluted by activities such as a gas station, a salvage yard, an auto body shop as well as disposal of batteries, waste oil and various other contaminants. Lead was identified as the main contaminant at this site and was found in the upper soil as well as groundwater. Phosphate amendments (e.g., ground phosphate rock and phosphoric acid) were applied to the site and the groundwater was monitored to judge the impact of the phosphate on the lead.

"In this study we were trying to come up with a simple, inexpensive remedy to fix lead in the soil and found phosphate is a very efficient way to bind lead,” said Dr. Lena Ma, a professor with the Soil and Water Department at the University of Florida. The FIPR studies that have been done have provided lab data and short-term testing. While there is interest in this as a potential remediation technique, there is a need for the longer-term field testing for regulators to consider using it.

Results of the pilot-field study is one of the first field experiments to assess the in situ stabilization technology of phosphate-induced lead immobilization. Dr. Ma has presented her work in conferences and published her findings in refereed-journals. She is recognized nationally and internationally as an expert on using phosphate to immobilize lead in soils.