Analysis - The Institute for Southern Studies

controls like surface-impoundment phase-out, or reduced because releases are caught earlier. These benefits, and how they relate, are described
in the section below.
First, even in the absence of federal regulations, CCR disposal units will not leach and cause cancers in all cases estimated through the
evaluation above. Even without federal regulation, there will be facilities that discover contamination and clean the contamination up before
cancers occur, either due to state regulations or good practice. Where exposures are identified, this RIA assumed that the pathway will be cut
off (e.g., through provision of alternative water sources). Even facilities that fail to prevent contamination may detect that contamination and
clean it up at a later time, although after exposure has occurred. This Step of the estimation attempted to account for these practices.
To estimate the different speed and cost of groundwater remediation likely under the baseline and under the three regulatory scenarios (i.e.,
Subtitle C, Subtitle D and Subtitle D Prime), this RIA began by examining the differences across states in groundwater monitoring
requirements pertaining to CCR disposal units, and focused on groundwater monitoring requirements because adequate monitoring is needed to
determine whether a release has occurred. This RIA assumes that, where releases of concern have been identified, and particularly where
people may be at risk, drinking water pathways will be cut off and alternative drinking water will be provided. Then calculated the percentage
of CCR disposed by each state, and noted which of three levels of groundwater monitoring were required:
1. No monitoring requirements
2. Monitoring requirements for only future newly constructed CCR disposal units
3. Monitoring requirements for both future new and existing CCR disposal units
Then EPA tracked the percentage of total waste that was discarded by facilities in states requiring each of these three monitoring scenarios.
Exhibit 5A-9 below presents these percentages for states requiring at least some monitoring (categories 2 and 3 above) and states requiring
monitoring at exiting facilities (category 3 above). The first value in the table, 91%, is the percentage of CCR discarded in landfills that impose
some form of monitoring requirements, whether for new landfills only, or for both new and existing landfills. 62% is the percent of CCR
discarded in landfills that impose monitoring requirements on both new and existing CCR disposal units (a subset of the 91%). 127 Percentages
are also provided for CCR that are managed in surface impoundments. Appendix K9 provides these data for each individual state.
127 Some states may require monitoring only for off-site units; however, in the absence of a specific breakdown, EPA made the assumption that on-site units would be
monitored in all states that require monitoring.
123