ENVIRONMENTAL IMPACTS OF PHOSPHOGYPSUM VS. BORROW PITS IN ROADFILL CONSTRUCTION

Abstract

A comparison was performed of the environmental impacts of using phosphogypsum versus conventional fill materials (e.g., from borrow pits) for road construction. The study compared a hypothetical roadway with an actual roadway in Florida; the two facilities differed only in that phosphogypsum was employed as fill material instead of conventional materials. The effect of the two construction approaches on the plant and animal communities was considered, as was the impact on the surface and ground water. A summary was made of the comparative impacts, and a comparison matrix was constructed using integral numbers to depict impacts ranging from – 5 (most impact) to 0 (none) to + 5, showing most benefit of the part of the project on a given resource. Values were subjective, based upon investigators' experience. Four categories (plant and animal communities, water quality, water resources, and air quality) were considered. The cumulative total was +12 for phosphogypsum and – 6 for conventional fill material.

Keywords:

• Phosphogypsum
• Road fill
• Borrow pits

ACKNOWLEDGMENTS

We gratefully acknowledge the support of the Florida Institute of Phosphate Research (through contract 96-01-139R), project coordination and helpful comments by Mr. G. Michael Lloyd of FIPR, and the inspiration of Dr. Scott Emery.