Analysis - The Institute for Southern Studies

More documents

Recommendations

Info

This RIA extracted only those results from the EPA 2009 risk assessment to either represent (a) conventional CCR (i.e., fly ash, bottom ash, boiler slag, and flue gas desulphurization waste managed in the landfill or impoundment without mixing with other materials), or (b) CCR comanaged with coal refuse. 113 Of these results, only those for trivalent arsenic were used. 114 For the primary analysis, it was assumed that all arsenic was speciated in this manner. As noted in the EPA source data, arsenic III and arsenic V cancer risk results for unlined surface impoundments that co-dispose CCR with coal refuse were not statistically different at the 90 th percentile, and these risks are likely to drive the population risk estimates. A sensitivity analysis was conducted where all arsenic was assumed to be speciated in the arsenic V state. This analysis is presented in Appendix K5. Finally, risks for both adult and child receptors were included so that each group would be accurately represented. Once all of these data were collected they were sorted by CCR disposal unit and liner type. This analysis reflects possible groundwater and surface water interactions that could affect the population risk estimates. In situations in which the modeled distance to a surface water body was less than the modeled distance to a drinking water well EPA assumed that the groundwater plume is fully intercepted by a surface waterbody. 115 To this end, EPA extracted the model inputs for the distance to groundwater wells and the distance to surface waterbodies used in the EPA source, randomly selected from input distributions. 116 These two were then compared using a logical test in Microsoft Excel. This test returned a 0 if the surface waterbody was closer than the drinking water well and 1 if it was not. Thus, a 1 was a positive indication that the contaminant plume in that model run reached the groundwater well. Finally, EPA extracted the exposure durations used in each model run from the EPA-ORCR 2009 CCR risk report to capture the fraction of the individual’s lifetime risk that was experienced in a one-year period. EPA accomplished this by matching the probabilistic exposure duration inputs, to their corresponding age category. Then, each probabilistic run was sorted to return the exposure duration of the adult and child age category. These Monte Carlo data constituted a weighted approach for estimating individual human cancer risks. Population risk is typically calculated by multiplying risk results by the affected population. Since there were thousands of equally valid model iterations, this RIA assigned each of these risks an equal weight in its final population risks by using the average of these individual risks. Individual risk estimation took into account the fact that the contaminant plumes might be intercepted by surface waterbodies by multiplying by either 0 or 1 as identified above. Each of these risks was then divided by exposure duration to estimate the yearly cancer risk. 117 Once all of these risks were calculated for a given WMU/liner type they were summed and divided by the number of iterations to give the average one year increment of risk for that WMU/liner type at the peak risk. Thus, the final equation that was used for calculating average risks can be stated as: 113 Fluidized Bed Combustion waste results were not deemed appropriate for use for the reasons discussed in EPA “Human and Ecological Risk Assessment of Coal Combustion Wastes,” Office of Resource Conservation & Recovery, August 2009. 114 A 1981 Oak Ridge National Laboratory study states “As (III) is likely to be the predominant arsenic species in ash pore water and groundwater.” Source: Turner, Ralph R. “Oxidation State of Arsenic in Coal Ash Leachate,” Environmental Science & Technology, Vol.15, Number 9, September 2001. 115 Full interception will not occur in instances where the waterbody is shallow, the waterbody is man-made, or the facility is oriented perpendicular to the waterbody. This simplifying assumption serves to minimize the influence of the model runs in which interception may have occurred, but was not reflected in EPA “Human and Ecological Risk Assessment of Coal Combustion Wastes,” Office of Resource Conservation & Recovery, August 2009. 116 For further discussion of how these distributions were developed, see Appendix C of EPA “Human and Ecological Risk Assessment of Coal Combustion Wastes“ Office of Resource Conservation and Recovery, Washington, DC, August 2009. 117 For further discussion of cancer risks and exposure durations, see Appendix K4 of this RIA. 116
RISKn WELLREACH iRISK EDn N Where: iRISK = Average increment of lifetime cancer risk from a 1-year exposure RISKn = Risk result for the nth model run WELLREACH = 0 if plume is intercepted by a surface water body, 1 otherwise EDn = Exposure duration for the nth model run n = Iteration number N = Number of iterations The results are presented in Exhibit 5A-3 below. For each, the results are presented for both adults and children under each of the WMU/liner scenarios. For full distributions of individual risks before averaging, see Appendix K6 – Distributions. Exhibit 5A-3 Peak One Year Risks For CCR Cancer Conventional CCR CCR Co-managed With Coal Refuse Liner - Receptor Landfills Impoundments Landfills Impoundments Unlined - Adult 6E-06 4E-05 5E-06 2E-04 Unlined - Child 1E-05 1E-04 1E-05 4E-04 Clay-Lined - Adult 3E-06 3E-05 2E-06 1E-04 Clay-Lined - Child 7E-06 6E-05 4E-06 2E-04 Step 4. Extrapolate Annual Cancer Risks from Peak Cancer Risks The peak risks that were calculated occur well after cancers can first materialize. Thus, constraining the benefits to only the peak population risks significantly underestimates total cancers avoided. To compensate for this shortfall, this RIA formulated an approach illustrated in Exhibit 5A-4 below. The blue parabolic curve for population risk is based on the well concentrations over time in the results. While EPA cannot reconstruct the exact curve due to data availability issues, a parabolic curve represents groundwater contamination. From this shape it is clear that the peak population risks only capture a fraction of total population risks. Using an assumption of linear increases to the peak and linear decreases from the peak, produced the simplified risk profile seen as a red line in Exhibit 5A-4. 117
Page 1 and 2:
Regulatory Impact Analysis For EPA
Page 3 and 4:
Table of Contents Executive Summary
Page 5 and 6:
Executive Summary This RIA evaluate
Page 7 and 8:
impoundments, the relative number t
Page 9 and 10:
Summary Exhibit 3 Induced Effect of
Page 11 and 12:
Summary Exhibit 6 Comparison of Reg
Page 13 and 14:
Chapter 1 Problem Statement: The Ne
Page 15 and 16:
Bevill Amendments 10 which exempted
Page 17 and 18:
Just three weeks after the TVA’s
Page 19 and 20:
2. Waste & Environmental Management
Page 21 and 22:
This RIA did not discover similar d
Page 23 and 24:
Exhibit 2A Identity of Other Indust
Page 25 and 26:
Require review of surface impoundme
Page 27 and 28:
Chapter 3 Baseline CCR Management i
Page 29 and 30:
Exhibit 3C below, these 495 coal-fi
Page 31 and 32:
Exhibit 3C State-by-State Electric
Page 33 and 34:
3B. Types of CCR Disposal Units Es
Page 35 and 36:
92 plants Offsite landfill fly ash
Page 37 and 38:
electric utility plants in the data
Page 39 and 40:
Exhibit 3E Annual CCR Disposition f
Page 41 and 42:
3D. Size of CCR Disposal Units The
Page 43 and 44:
costs for each type of disposal (no
Page 45 and 46:
annual sampling for surface impound
Page 47 and 48:
o Of the 25 state regulations revie
Page 49 and 50:
Exhibit 3I Baseline Compliance with
Page 51 and 52:
Baseline CCR Disposal Cost Estimati
Page 53 and 54:
Before-tax costs: 50-year period:
Page 55 and 56:
Baseline “Engineering Control”
Page 57 and 58:
assume that the same water trucks w
Page 59 and 60:
memorandum to George Garland, EPA,
Page 61 and 62:
Exhibit 3K Summary of Industry & St
Page 63 and 64:
($80,000 per year average Subtitle
Page 65 and 66: Validity Check of Baseline Cost Est
Page 67 and 68: Chapter 4 Estimated Cost for RCRA R
Page 69 and 70: B. Ancillary costs for CCR disposal
Page 71 and 72: location restriction mitigation inv
Page 73 and 74: o Impoundment berms: The average su
Page 75 and 76: State government average cost per w
Page 77 and 78: corrective action remedies usually
Page 79 and 80: Exhibit 4A Two Case Studies: Possib
Page 81 and 82: Biennial Report”). According to E
Page 83 and 84: 4B.3 Land Disposal Restriction Cost
Page 85 and 86: The TVA cost study did not estimate
Page 87 and 88: Using the EPA ORCR 2009$ updated un
Page 89 and 90: Exhibit 4D Comparison of Annual O&M
Page 91 and 92: Exhibit 4E Summary of Wet Conversio
Page 93 and 94: o Recent Trend in CCR Impoundment P
Page 95 and 96: from coal to other fuels such as na
Page 97 and 98: o Result of Dry Conversion Cost Upd
Page 99 and 100: As summarized below in comparison t
Page 101 and 102: 17% phase-out trend suggest the fut
Page 103 and 104: RIA 50- ye ar period Actual company
Page 105 and 106: 4C. State-by-State Distribution of
Page 107 and 108: 4D. Cost Estimation Uncertainty Thi
Page 109 and 110: Exhibit 4N Cost Estimation Uncertai
Page 111 and 112: In contrast to the Exhibit 5A list
Page 113 and 114: Step 2. Determine Potentially Affec
Page 115: Step 3. Apply EPA-ORCR 2009 Arsenic
Page 119 and 120: The constant slope allowed estimati
Page 121 and 122: Step 6. Monetize Future Avoided Can
Page 123 and 124: controls like surface-impoundment p
Page 125 and 126: Finally, for Subtitle C, there woul
Page 127 and 128: Exhibit 5A-12 Percentile of Cleanup
Page 129 and 130: Exhibit 5A-16 Per-Site Groundwater
Page 131 and 132: Multiple CCR disposal units at a si
Page 133 and 134: 5B. Benefit of Preventing Future CC
Page 135 and 136: As displayed below in Exhibit 5B-2,
Page 137 and 138: Where: = Observed arrival rate (0.
Page 139 and 140: Step 3. Calculate Future Impoundmen
Page 141 and 142: some surface impoundment regulation
Page 143 and 144: Exhibit 5B-8 Poisson Distribution (
Page 145 and 146: With these new distributions, EPA p
Page 147 and 148: Exhibit 5B-12 Scenario #2: Cleanup
Page 149 and 150: 5C. Induced Effect of RCRA Regulati
Page 151 and 152: Exhibit 5C-1 Estimate of Annual Mat
Page 153 and 154: Exhibit 5C-3 below presents a 2004
Page 155 and 156: To avoid double-counting of economi
Page 157 and 158: 5C2. Potential Effect of RCRA Regul
Page 159 and 160: Others take a different view on how
Page 161 and 162: Exhibit 5C-7 EPA Extrapolation of E
Page 163 and 164: Based on the most recent CCR benefi
Page 165 and 166: Beneficial uses of CCR have been co
Page 167 and 168:
Exhibit 5C-12 Beneficial Use Trend
Page 169 and 170:
Increases due to increased disposal
Page 171 and 172:
“Using [coal] fly ash in building
Page 173 and 174:
Exhibit 5C-14 Historical Annual Per
Page 175 and 176:
Hypothetical expansion of CCR custo
Page 177 and 178:
Step 6: Apply Estimated Induced Eff
Page 179 and 180:
Exhibit 5C-16 Scenario #1: Increase
Page 181 and 182:
Exhibit 5C-17 Scenario #2: Decrease
Page 183 and 184:
Exhibit 5C-18 Beneficial Use Trends
Page 185 and 186:
Exhibit 5C-19 Scenario #1: Benefit
Page 187 and 188:
Exhibit 5C-21 Scenario #2: Cost of
Page 189 and 190:
Step 10: Quantify Potential Capacit
Page 191 and 192:
Chapter 6 Comparison of Regulatory
Page 193 and 194:
Exhibit 6B Comparison of Regulatory
Page 195 and 196:
Exhibit 6D Comparison of Regulatory
Page 197 and 198:
Exhibit 6F Comparison of Regulatory
Page 199 and 200:
Exhibit 6F Scaling Factors (Extrapo
Page 201 and 202:
Exhibit 6G Estimate of Subtitle D (
Page 203 and 204:
detect contamination early and thus
Page 205 and 206:
Step 1: Downloaded the annual milli
Page 207 and 208:
Exhibit 7A State by State Breakout
Page 209 and 210:
Small government: Based on the RFA/
Page 211 and 212:
Step 3 & Step 4: Determine and docu
Page 213 and 214:
Factor #2 of 2: The small business
Page 215 and 216:
how much they use or indeed how muc
Page 217 and 218:
Collection of Minority & Low-Income
Page 219 and 220:
Comparison of Minority & Low-Income
Page 221 and 222:
Exhibit 7G Minority and Low-Income
Page 223 and 224:
Exhibit 7H Comparison of Minority a
Page 225 and 226:
o The state-by-state range of minor
Page 227 and 228:
CCR fraction #3: CCR fraction #4:
Page 229 and 230:
7D. Child Population Statistics (Ex
Page 231 and 232:
Comparison of Child Populations Liv
Page 233 and 234:
Count of plant unique ZCTAds Exhibi
Page 235 and 236:
Exhibit 7K Comparison of Child Popu
Page 237 and 238:
7E. Unfunded Mandates (UMRA) & Fede
Page 239 and 240:
Findings for UMRA Impact and Federa
Page 241 and 242:
Exhibit 7M List of 74 Coal-Fired El
show all

Analysis - The Institute for Southern Studies

Create successful ePaper yourself

Delete template?

Save as template?