Groundwater flow directions indicated by
.
Groundwater flow out of the ash basins is primarily east toward the river. In the northern portions of the site, flow is north toward the discharge canal.
At this site, boron and sulfate are considered the best constituents to indicate the maximum physical extent of the ash basins’ impact on groundwater, though sulfate is also observed in background wells. The
show physically where boron and sulfate are estimated to be greater than the North
Carolina 2L groundwater quality standard.*
Duke Energy
Property Boundary
Ash Basin Boundary
*EPA has identified boron, calcium, chloride, fluoride, pH, sulfate and total dissolved solids (TDS) as leading indicators to detect coal combustion residuals in its federal regulations.
This illustration is a simplified version of Figure ES-1 in the HDR Comprehensive
Site Assessment Executive Summary for Allen Steam Station.