Analysis - The Institute for Southern Studies

Aggregate benefits from cancer risk reductions and avoided remediation costs are summarized in Exhibit 5A-18 below. These benefits are
calculated by subtracting the costs resulting under that option from the costs resulting under the baseline (i.e., cost avoided).
Exhibit 5A-18
Present Value of Future Avoided Human Cancer Risks
& Avoided Groundwater Remediation Cost Benefits
($millions present value over 50-years)
Subtitle C Subtitle D Subtitle D’
@ 3% discount
Groundwater Remediation Costs Avoided* $1,491 $571 $286
Human Cancer Risks Avoided $1,825 $750 $375
Total $3,316 $1,321 $661
@ 7% discount
Groundwater Remediation Costs Avoided* $466 $168 $84
Human Cancer Risks Avoided $504 $207 $104
Total $970 $375 $188
Note:
* Calculated by subtracting the present value future groundwater remediation cost estimated in Exhibit
5A-17 for each regulatory option, from the estimated baseline present value in that same Exhibit.
Step 8. Characterize Cancer Risk Estimation Uncertainties
There are a number of uncertainties associated with the annualized cancer estimates calculated in this RIA which are likely to under-estimate
groundwater protection benefits:
Estimates do not account for historic releases at operating plants. These releases could lead to further migration and future cancer risks
without proper regulatory actions like groundwater monitoring.
A linear slope for individual cancer risk was used to approximate the increase in cancer risks instead of the parabolic curve.
Approximately 18% of plants dispose of CCR off-site only. Since these facilities were not accounted for, additional populations would be
exposed to arsenic cancer risks from disposal as recently illustrated by the Gambrills, MD and Chesapeake, VA damage cases.
Three new research studies 131 (2006, 2008, 2009) from EPA’s Office of Research and Development, indicates that landfills may leach toxic
metals much faster than originally believed. The damage cases at Gambrills MD and Chesapeake VA resulted in groundwater
contamination much more quickly than would be expected, and are therefore consistent with this research.
131 The three new EPA studies are:
1. “Characterization of Mercury-Enriched Coal Combustion Residues from Electric Utilities Using Enhanced Sorbents for Mercury Control,” EPA 600/R-06/008.
Office of Research and Development. Research Triangle Park, NC. January 2006.
130