Analysis - The Institute for Southern Studies

Exhibit 5A-12
Percentile of Cleanup Levels in the EPA-ORCR 2009 CCR Risk Study
Clean Up Level
UL A
LF
CL A
LF
UL C
LF
CL C
LF
UL A
SI
CL A
SI
UL C
SI
CL C
SI
1.00E-04 78% 83% 74% 85% 46% 59% 30% 43%
1.00E-05 55% 59% 42% 57% 15% 24% 12% 21%
1.00E-06 36% 35% 18% 28% 5% 7% 3% 8%
Model results equal to or above these percentiles would require a state or federal cleanup. In other words, the percentage of sites above the
cleanup level displayed in Exhibit 5A-13 can be derived by subtracting the percents in Exhibit 5A-12 above from 100%. However, while
states may require remediation of all groundwater, whether or not it is potable, they may also choose not to on a site by site basis. As discussed
in the EPA-ORCR 2009 CCR risk report, it is estimated that two-thirds of sites are located closer to a surface waterbody than to the nearest
groundwater well. Therefore, sites located on surface waterbodies may not be cleaned in some states. This 2/3 decrease is accounted for in the
second set of values in Exhibit 5A-13.
Exhibit 5A-13
Percent of Electric Utility Plants Requiring Future Groundwater Remediation
Clean Up Level
UL A
LF
CL A
LF
UL C
LF
CL C
LF
UL A
SI
CL A
SI
UL C
SI
CL C
SI
Assuming All Groundwater is Remediated
1.00E-04 22% 17% 26% 15% 54% 41% 70% 58%
1.00E-05 45% 41% 58% 43% 85% 76% 89% 79%
1.00E-06 65% 65% 82% 72% 96% 93% 97% 93%
Assuming Only Potable Groundwater is Remediated
1.00E-04 7% 6% 8% 5% 18% 13% 23% 19%
1.00E-05 15% 14% 19% 14% 28% 25% 29% 26%
1.00E-06 21% 21% 27% 24% 32% 31% 32% 31%
The number of utility plants with each type of CCR disposal, liner type, and management combination was calculated by taking the Appendix
F plant data from this RIA and combining it with the conventional versus co-managed rates.
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