An Assessment of Aquifer Storage and Recovery and Mercury Methylation in the South Florida Everglades Ecosystem

Project Investigator: David P. Krabbenhoft Project Start Date: 2003 End Date: 2005 Scope of Work Publications

Summary

The objective of this project is to develop a hydrogeochemical framework of mercury and methylmercury in the hydrogeologic system in which ASR will be developed in the Upper Floridan Aquifer.

There are many uncertainties regarding the use of large-scale aquifer storage and recovery (ASR) technology in south Florida, including suitability of proposed ASR source waters, water quality concerns and the potential for mercury bioaccumulation (NRC 2002). The type of source waters used for aquifer recharge in south Florida includes treated drinking water, untreated ground or surface water, and reclaimed water. The source water planned for the Comprehensive Everglades Restoration Plan ASR program is untreated or partially treated groundwater or surface water (Reese 2002).

The objectives of this scope of work are to determine: (1) background levels of mercury, methylmercury and other chemical species in selected aquifers or subaquifers; (2) the distribution of mercury and methylmercury in the aquifer system in South Florida; (3) the conditions under which methylation of mercury may occur in aquifer materials, and (4) potential changes in water chemistry that could enhance methylmercury production (eg., sulfate and carbon additions) as a result of injecting water for storage in, or post recovery from, the Floridan aquifer system in south Florida.