Status of US-EPA Risk Evaluation and Possible Regulations on FGD-Gypsum Uses in Agriculture.

In 2008, a catastrophic spill of coal fly-ash prompted EPA to conduct an assessment of the regulation associated with handling of all coal combustion Residues (CCR) and for the management of these materials at facilities nationwide. While the concern was initiated with the spill associated with coal fly-ash storage lagoons, the evaluation included all possible uses and disposal of CCR products regulated under RCRA, which included Flue Gas Desulfurization Gypsum (FGDG). Changes in the new rules primarily focused on managing of CCR in landfills and holding ponds, but it did cover the utilization of FGDG for “beneficial use”. EPA did conclude that CCRs were not Hazardous Solid Wastes in 2016. In the rule, the encapsulated uses of FGDG are very clear because these uses are well established and risk assessments have been conducted. More problematic to EPA were the unencapsulated uses, of which FGDG use in agriculture is included. In the rule, the EPA allows for the CCR products to be exempt from the landfill rules and otherwise be utilized as a byproduct if it meets the 4 criteria defining “beneficial use”. One of the criteria requires a comprehensive risk evaluation for agricultural use of FGDG, which is still in progress. This evaluation considers all possible pathways for movement of chemical constituents in FGDG to any possible receptor where harm might occur, much like previous considerations of biosolids and other soil amendments. The rule provides guidelines for ongoing use of FGDG, but also states that “The Agency has also been working with the U.S. Department of Agriculture to address the risks associated with the agricultural use of CCR”. This risk evaluation is ongoing, and details regarding the progress will be addressed in the presentation.