Analysis - The Institute for Southern Studies

3D. Size of CCR Disposal Units
The size of CCR disposal units ranges from modest to very large, with some impoundments covering 1,500 acres or more. Sizing of the units
is based on the annual tonnage of CCR placed in the unit. CCR disposal unit size assumptions for this RIA are adopted from Section 4.4.1 of
the 2005 DPRA Report:
Landfills sizes:
Designed as “combination fill landfills”
•
3.8 million cubic yards capacity
•
50% of the capacity excavated below grade
•
40-year capacity (i.e., operating lifespan) 44
•
Per-unit surface area size ranges from 12 acres for 10,000 tons per year to over 2,000 acres for 2,000,000 tons per year.
Designed as “pile fill landfills”
•
3.4 million cubic yards capacity
•
5% of the capacity excavated below grade
•
40-year capacity (i.e., operating lifespan)
•
Per-unit surface area ranges from 16 acres for 10,000 tons per year to over 3,000 acres for 2,000,000 tons per year.
Surface impoundment sizes:
o
100% of capacity below grade
o
40-year capacity
o
Per-unit surface area ranges from 30 acres for 10,000 tons per year, 140 acres for 50,000 tons per year, 500 acres for 200,000 tons per
year, 1,400 acres for 500,000 tons per year, and 5,500 acres for 2,000,000 tons per year.
44 For the 30 Nov 2005 DPRA report (“Estimation of Costs for Regulating Fossil Fuel Combustion Ash Management at Large Electric Utilities Under Part 258”, docket
document ID nr. EPA-HQ-RCRA-2006-0796-0469), the EPA asked utility industry representatives for the typical lifespan years of CCR landfills and impoundments.
Industry representatives provided a 40-year estimate for both. This estimate is supported by data provided by industry in the 1995 EPRI Comanagement Survey. In the
EPRI Survey, data describing six CCR landfills noted the year the unit was opened and the estimated date of closure. The average life expectancy is 34 years and the
median life expectancy is 38 years. Similarly, data provided for 18 CCR impoundments indicate an average life expectancy of 45 years and a median life expectancy of 46
years. Therefore, this RIA assumes a 40-year lifespan for both landfills and impoundments.
41