Analysis - The Institute for Southern Studies

memorandum to George Garland, EPA, 30 April 1995. Additional supporting information obtained from EPA “Estimating Costs for the
Economic Benefits of RCRA Noncompliance,” September 1997.
7. Baseline disposal unit location restrictions
Baseline cost not estimated in this RIA.
8. Baseline closure capping to cover unit
The cost estimate for this engineering control does not include the closure plan cost or closure certification costs. Capping costs are a large
capital expense. So, if a unit is expected to close in one year the total capping cost is assigned to the last year in the life of the unit. However,
businesses are likely to borrow money from a bank for these large capital costs and annualize them over a set period of time, for example, 10 or
20 years. Incremental cost estimates in the cost model are overestimated for large capital expenditures applied to existing units that have been
added over short time periods. In addition, owners are likely to close these units prior to the proposed rule coming into effect if promulgated as
a final rule. This RIA assumes the same requirements for both landfills and impoundments:
• Synthetic cap with drainage layer is comprised of a 60 mil HDPE synthetic liner, 1 foot sand, filter fabric, 1.5 foot slope and earth fill, 0.5
foot topsoil, and vegetation. It includes a perforated pipe for drainage collection.
• Synthetic cap without drainage layer is comprised of a 60 mil HDPE synthetic liner, 1.5 foot slope and earth fill, 0.5 foot topsoil, and
vegetation.
• Clay cap is comprised of 2 feet of off-site clay, 0.5 foot topsoil, and vegetation. Cover costs would be lower if on-site clay is available.
• Soil/clay cover is comprised of 0.5 foot clay, 0.5 foot earthfill, and 0.5 foot topsoil, and vegetation. Cover costs would be lower if on-site
clay is available.
• Soil cap is comprised of a 1.5 foot slope and earth fill, 0.5 foot topsoil, and vegetation. The slope of the cap is assumed to be 0.02:1 (rise:run)
with a cover toe slope of 4:1 (run:rise).
9. Baseline post-closure groundwater monitoring requirements
• Same requirements for both landfills and impoundments
• Baseline post-closure monitoring is assumed to comprise 30 years of groundwater monitoring and surface water monitoring on a semi-annual
basis. The physical parameters (i.e., point of compliance, number of wells, sets of chemical indicators and sets of chemical constituents
monitored, and semi-annual frequency) and unit cost are assumed identical as defined in the baseline groundwater monitoring cost item 1
above in this section of the RIA.
• However, post-closure monitoring costs are estimated in this RIA assuming an annual sum is placed in a fund by affected entities (i.e., electric
utility owners) during the assumed average 40-year operating life of the CCR disposal unit. At the time of closure sufficient monies will be
available in the fund to cover post-closure monitoring for the next 30 years beyond end-of-lifespan, assuming an annual interest rate of 7%.
10. Baseline storage tank/container design and operating standards
Baseline cost not estimated in this RIA
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