A subsurface investigation at Area G (metal sludge) and O (explosives) ponds located in the Lone Star Ammunition Plant, Texarkana, Texas, was initiated. The study included review of existing data, site drilling, and sampling and analysis of soil and water.

Results indicate that the ponds are underlain by massive clay beds (aquiclude), and the potential for contamination of the usable ground water supply appears to be remote. No significant migration of hazardous contaminants through subsurface soils was observed.

Groundwater quality is poor due to high total dissolved solids (TDS) and soluble salt content. However, it is relatively free of trace metals, trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX), and trace organics.

It is recommended that these ponds be closed and that appropriate post-closure maintenance and monitoring, as mandated under the Resource Conservation and Recovery Act, be implemented.