COMMENTS. US Environmental Protection Agency

Transcription

1 COMMENTS US Environmental Protection Agency Hazardous and Solid Waste Management System; Identification and Listing of Special Wastes; Disposal of Coal Combustion Residuals From Electric Utilities Docket ID: EPA HQ RCRA (Federal Register / Volume 75, Number 118 / Monday, June, 21, 2010; [EPA HQ RCRA ; FRL ]; RIN 2050 AE81) Submitted by: ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue Palo Alto, CA November 18, 2010 For more information, please contact: Ken Ladwig keladwig@epri.com

2 Contributors to this document include: EPRI K. Ladwig J. Lingle URS Corporation G. Blythe S. Ferguson M. Rokoff Veritas Economic Consultants D. Santoianni J. Whaley M. Bingham Natural Resource Technology, Inc. B. Hensel Gradient A. Lewis S. Sax G. Jegadeesan

3 Contents Executive Summary... 1 Costs of RCRA Subtitle C Regulation... 1 Risk Assessments... 3 Damage Cases... 4 Leaching Environmental Analysis Framework (LEAF)... 5 Unencapsulated Uses Introduction Costs of Subtitle C Regulation Basis for Cost Estimates National Cost Estimate References Cited Risk Assessments Human and Ecological Risk Assessment Leachate Input Data Sites Used for Generating Leachate Data Input Use of High Non-Detects in Site Averages Higher Than Possible Maximum Leaching Concentrations Averaging Small Datasets Uncertainty and Sensitivity Conservative Input Data Additive Risks Relationship to Damage Cases Distance to Surface Water Risk Assessment Associated with Inhalation of CCR Particulates Non-Groundwater Pathway Risk Assessment Fugitive Dust Risk Assessment References Cited Use of Risk Information in Regulatory Impact Assessment Count of Potential Receptors Use of Risk Assessment Information to Calculate Benefits of the Regulation References Cited Damage Case Reports US EPA Damage Cases New Alleged Damage Cases References Cited EPRI Comments i November 18, 2010

4 6 Leaching Environmental Assessment Framework Protocol Use of LEAF Data Comparison to Field Data Changes to CCR Characteristics References Cited Unencapsulated Uses of CCRs Agricultural Uses of FGD Gypsum FGD Gypsum Agricultural Network Greenhouse Studies Gypsum Characterization Engineered Structural Fills Base/Subbase Applications References Cited Landfill Criteria Seismic Location Criteria Groundwater Monitoring Alternative Designs References Cited EPRI Comments ii November 18, 2010

5 Executive Summary On June 21, 2010, the US Environmental Protection Agency (US EPA) published the proposal to develop national regulations under the Resource Conservation and Recovery Act (RCRA) for coal combustion residuals (CCRs) titled Hazardous and Solid Waste Management System; Identification and Listing of Special Wastes; Disposal of Coal Combustion Residuals From Electric Utilities in the Federal Register (Fed. Reg. 75[118], ) (Proposed Rule). The preamble to the Proposed Rule raised several questions on technical issues related to CCR management, and requested additional information to address these questions. The Electric Power Research Institute (EPRI) appreciates the opportunity to provide data and information to US EPA on several of these technical issues. EPRI has been engaged in CCR research for more than 30 years and has developed a large knowledge base that is relevant to many of these issues. EPRI has developed a good working relationship with US EPA in the past on CCR research, and we look forward to continuing information sharing and collaborative research to help address technical issues raised during and after this comment period. The EPRI comments do not endorse any particular regulatory option put forth by US EPA in the June 21 proposal. The purpose of these comments is to provide technical information that can be used by US EPA and others to develop regulations based on the best data available. Attachments provide complete documentation to support our comments. Costs of RCRA Subtitle C Regulation EPRI performed a detailed assessment of the incremental capital and operational costs of RCRA Subtitle C requirements above and beyond current practice. This evaluation includes costs incurred upstream of the disposal site, in other words those costs incurred within the power plant from point of generation (POG) through loading of the trucks, as well as incremental costs at the disposal site. The assessment evaluated costs to upgrade seven subsystems of the power plant: bottom ash handling, fly ash handling, flue gas desulfurization (FGD) by-product handling, plant site runoff management, disposal site management, wastewater treatment, and administrative and operation and maintenance (O&M) activities. Cost estimates for each of the subsystems were derived for two model plant configurations: a 400 megawatt (MW) plant with two 200 MW units (small plant), and a 1600 MW plant with two 800 MW units (large plant). The cost estimates were then applied to a national model for 377 power plants (plants <100 MW were not included) containing site-specific unit-level and plant-level EPRI Comments 1 November 18, 2010

6 information. National costs were estimated for three beneficial use scenarios selected to parallel the US EPA assumptions: continued use of CCRs at current rates for encapsulated uses and mine placement, an 11% increase in use rate under the Proposed Subtitle C rule for these applications, and an 18% decrease in use rate under the Proposed Subtitle C rule for these applications. Revenue gains/losses associated from sales were not included in this analysis. The analytical model used to develop these cost estimates utilized a Monte Carlo statistical model to account for parameter uncertainty in input cost components, and uncertainty in disposal decision by individual coal-fired power plants. Ranges of costs for specific scenarios represent the 5 th to 95 th percentile of the Monte Carlo runs. The results are summarized in Table ES-1. Total costs over the 20 year period were estimated to range from $55 billion to $77 billion using a 7 percent discount rate. Beneficial use scenarios did not significantly affect the outcome; however use of a lower discount rate (3 percent) increased the estimated costs by more than 40 percent. This analysis does not represent the total cost of CCR management; it considers only the costs over baseline (i.e., current) costs that are attributable to Subtitle C regulation. Disposal site construction and operation costs are not included in this analysis because the designs for Subtitle C and Subtitle D are essentially the same. Table ES-1 Estimated Costs of Subtitle C Regulation for Three Beneficial Use Scenarios and Two Discount Rates. Costs Are Present Value (2010) in Billions of Dollars Over 20 Years. Scenario 1 Incremental Costs for Subtitle C Option 2,3 (7% discount rate) Incremental Costs for Subtitle C Option 2,3 (3% discount rate) Scenario #1: Encapsulated Use Rate Unchanged Scenario #2: Encapsulated Use Decreases 18% Scenario #3: Encapsulated Use Increases 11% $55.31 $74.53 $78.92 $ $56.45 $76.84 $80.75 $ $54.66 $73.20 $77.74 $ The beneficial use scenarios mirror the US EPA assumptions in the RIA. 2. Incremental cost of the Subtitle C regulation above baseline management costs. 3. Based on 377 power plants. Plants less than 100 MW were not included. EPRI Comments 2 November 18, 2010

7 Risk Assessments EPRI reviewed and provided specific comments on three risk assessments (RAs) that US EPA performed as part of the basis for developing national regulations: Human and Ecological RA, Nongroundwater Pathway RA, and Fugitive Dust RA. The Human and Ecological RA is a very large and complex undertaking, encompassing several types of CCR management facilities across all regions of the United States. Because of this broad application, the modeling by necessity requires considerable simplification, resulting in a high degree of variability and uncertainty in the results. As acknowledged by US EPA, a conservative approach was used in the RA where input data was uncertain, to ensure that potential risks were not underestimated. Such an analysis has value for developing qualitative comparisons (e.g., relative risks of unlined versus lined sites); however, due to the large ranges and degree of uncertainty in some of the input data, and the conservative approach used determine distributions for uncertain input data, the risk estimate results cover a relatively broad range and are not specific enough for establishing reliable quantitative risk levels (e.g., the absolute risk posed to an individual by a specific constituent). Because the proposed Subtitle C and Subtitle D disposal site designs are essentially the same, the RA does not provide a means for distinguishing risk reduction benefit between the two options. The results from the Human and Ecological RA were used by US EPA to estimate the number of potential arsenic cancer cases that might occur within one mile of the modeled CCR management sites, and subsequently to estimate the monetary benefits of the regulation with respect to cancer cases avoided in the Regulatory Impact Analysis (RIA). The number of potential receptors estimated by US EPA downgradient of CCR disposal sites is higher than our estimate of 6500 to 7800 individuals, but the estimates compare reasonably well given the scale of the analysis and the disparate methodologies used to make the estimates. In the analysis of cancer cases avoided, US EPA used two different cancer slope factors (CSF) for arsenic: the current Integrated Risk Information System (IRIS) CSF of 1.5 mg/kg-d based on skin cancer (yielding 145 potential excess cancer cases over a 75 year period), and a CSF of 26 mg/kg-d based on bladder and lung cancer developed by the National Research Council (yielding 2509 potential excess cancer cases over a 75 year period). However, only the higher CSF was used to calculate the monetary benefit of cancer cases avoided. Using the relatively conservative RA results and the higher CSF, and accounting for remediation at some of the sites, US EPA estimated a total of 726 excess cancer cases due EPRI Comments 3 November 18, 2010

8 to arsenic over the 75 year period, or about 10 per year. For perspective, the National Cancer Institute estimated that in 2009 there were 290,420 newly diagnosed bladder and lung cancers in the U.S. EPRI and others have commented extensively to US EPA on the scientific uncertainties in the more stringent CSF assessment. In other regulatory actions involving arsenic setting the arsenic Maximum Contaminant Level (MCL) and in assessments of several pesticides containing arsenic US EPA used a much lower CSF of 3.67 mg/kg-d. At a minimum, US EPA should also use the CSF of 3.67 mg/kg-d to calculate the monetary benefits associated with excess cancer cases avoided. Furthermore, US EPA assumes all of the arsenic is present as the more mobile and more toxic trivalent arsenic species to arrive at the estimate of 2509 potential excess cancer cases, despite evidence in the literature that suggests the pentavalent arsenic species is more common in coal ash. If the pentavalent species is assumed, the number of excess cancer cases over the 75 year period decreases from 2509 to 99. The screening modeling done in the Fugitive Dust RA is relatively general, and the worst case analysis posits a scenario that is not representative of CCR management sites. It does not provide much new insight to potential dusting issues at CCR landfills, or methods of dust control. Damage Cases EPRI performed a detailed assessment of the proposed and potential damage cases identified by US EPA in Our purpose in doing so was to collect and provide additional data to supplement the information available to US EPA on the nature and extent of groundwater impacts at the damage cases listed in the 2007 US EPA report, and to evaluate any common characteristics among these cases. In general, the damage cases are primarily older, unlined facilities. Remediation activities are either ongoing or completed at 26 of the 27 proven damage cases for which data are available (the status of one site is unknown), as well as most of the potential damage case sites. In most cases, off-site groundwater impacts were not documented. The damage case sites do not reflect the design of new lined CCR disposal site cells built over the last 15 years. Because the liner requirements proposed in the Subtitle D and Subtitle C options are identical, from a technical perspective the two options should perform equivalently to mitigate groundwater releases. We also performed a brief assessment of the alleged damage cases more recently published by Environmental Integrity Project, Earthjustice, and the Sierra Club. While we were not able to assess these sites in detail, we found several examples of possible errors or misinterpretations that merit further EPRI Comments 4 November 18, 2010

9 investigation. Prior to accepting these as either proven or potential damage cases, it is critical that each case be fully vetted by US EPA with at least the level of technical review as the previous alleged damage cases, and that the results be made available for public input. Leaching Environmental Analysis Framework (LEAF) The suite of procedures included in LEAF represents a comprehensive and sound laboratory protocol for evaluating leaching under a variety of conditions. Our primary concerns with the LEAF protocol are inappropriate use of the large volume of data generated, and the lack of field validation to help guide application of the data. Simply picking the highest concentration from the large dataset generated using the LEAF protocol and comparing it to a regulatory limit without considering the characteristics of the material or the application is not technically valid. For example, the LEAF protocol includes batch testing from ph 2 to ph 12, and the results presented in Table 4 of the Proposed Rule show ranges for fly ash leaching from ph 5.4 to While the range for all fly ashes is typically between 5 and 12, individual fly ash types are unlikely to span that ph range in typical disposal settings. Research by EPRI and others has shown that the ph of alkaline fly ash exposed to rainfall infiltration may stay above 10 for a relatively long period of time, and slowly evolve to a ph between 8 and 9 due to carbonation reactions. The appropriate ph range at which to evaluate these materials is between 8 and 12 for typical disposal environments. Similarly, an acidic ash exposed to rainfall infiltration is expected to slowly evolve to a ph between 7 and 8, so the appropriate ph test range may be between 4 and 8 in typical disposal settings. In addition, while the laboratory protocol is well developed, controlled field experiments are necessary to understand how the results from the LEAF protocol compare to actual field conditions. Such tests would allow calibration of the wide range of data generated using the LEAF protocol to the important variables that control field leachate generation. EPRI maintains an active research area dedicated to assessing CCR composition and leaching characteristics. We work closely with our environmental controls group to assess the potential impact that new and emerging air emission control technologies may have on both CCR environmental behavior and CCR use, and possible mitigation measures. We have also recently begun using the LEAF protocol in some of our characterization work, with a particular focus on how to interpret and use the data. EPRI Comments 5 November 18, 2010

10 Unencapsulated Uses Agricultural applications offer a well-demonstrated alternative beneficial use where FGD gypsum can be used to supplement or replace mined gypsum products. EPRI is engaged in a large, multi-year research effort to better define the soils and crops that benefit from FGD gypsum application, to determine the appropriate agronomic application rates, and to evaluate the occurrence and environmental fate of trace constituents in the gypsum. This research includes a network of field sites in seven states, greenhouse studies, and gypsum characterization. The United States Department of Agriculture (USDA) and US EPA are working on a risk assessment to develop risk-based concentration limits for FGD gypsum used in agriculture. We have been working to coordinate the EPRI research with USDA and US EPA and provide them with information as it becomes available. Most of this research will culminate in 2011, and will be available to help to inform the regulatory decision. EPRI has researched engineered structural fills and road applications since the late 1970s. This research contributes to a large body of literature in the United States documenting the successful engineering of structural fills and road applications using fly ash, bottom ash, and stabilized FGD materials over the last 20 to 30 years. Because of their lower cost and the environmental benefits of using by-products in place of virgin materials, the use of CCRs is well accepted by the construction industry. Ongoing research is evaluating factors controlling the potential for environmental impacts. EPRI has been working with utilities to develop a tool for use in evaluating the environmental feasibility of proposed fill projects, that incorporates environmental setting, leaching characterization, release potential, and potential receptors. Such an approach can serve as a starting point for a standardized procedure to be more fully developed among the many stakeholders with interests in the continued use of CCRs as a geotechnical material in engineered structural fills. EPRI Comments 6 November 18, 2010

11 1 Introduction On June 21, 2010, the US Environmental Protection Agency (US EPA) published the proposal to develop national regulations for coal combustion residuals (CCRs) titled Hazardous and Solid Waste Management System; Identification and Listing of Special Wastes; Disposal of Coal Combustion Residuals From Electric Utilities in the Federal Register (Fed. Reg. 75[118], ) (Proposed Rule). The Proposed Rule offered three basic approaches to CCR regulation under the Resource Conservation and Recovery Act (RCRA): a listed special waste under Subtitle C of RCRA; a solid waste under Subtitle D of RCRA; and a D Prime option which allows continued use of surface impoundments for their design life. The preamble to the Proposed Rule raised several questions on technical issues related to CCR management, and requested additional information to address these questions. The Electric Power Research Institute (EPRI) appreciates the opportunity to provide data and information to US EPA on several of these technical issues. EPRI has been engaged in CCR research for more than 30 years and has developed a large knowledge base that is relevant to many of these issues. EPRI has developed a good working relationship with US EPA in the past on CCR research, and we look forward to continuing information sharing and collaborative research to help address technical issues raised during and after this comment period. The specific information requests addressed in this comment package are related to the following seven items. Section 2 Section 3 Section 4 Section 5 Costs of Subtitle C regulation related to collection, storage, transportation and disposal of CCRs. In particular, costs related to power plant operations upstream of the disposal site. Risk assessments included as supporting information on the docket. - Human and Ecological Risk Assessment - Non-Groundwater Pathway Risk Assessment - Fugitive Dust Risk Assessment Use of risk information in the regulatory impact assessment. Damage case assessments provided by US EPA, EPRI, and Earth Justice/Environmental Integrity Project. EPRI Comments 7 November 18, 2010

12 Section 6 Section 7 Section 8 The new leaching protocol, Leaching Environmental Assessment Framework. Research on unencapsulated CCR uses. - FGD gypsum in agriculture - Structural fills - Road base/subbase Information related to selected landfill criteria. - Seismic impact zones - Groundwater monitoring - Alternative designs The EPRI comments do not endorse any particular regulatory option put forth by US EPA in the June 21 proposal. The purpose of these comments is to provide technical information that can be used by US EPA and others to develop sound regulations based on the best technical information available. This document includes the attachments listed below. In addition, any EPRI report referenced in this document is available to the public free of charge at epri.com. Attachment A Engineering and Cost Assessment of Listed Special Waste Designation of Coal Combustion Residuals Under Subtitle C of the Resource Conservation and Recovery Act, EPRI Report Attachment B Cost Analysis of Proposed National Regulation of Coal Combustion Residuals from the Electric Generating Industry, EPRI Report Attachment C Characterization of Field Leachates at Coal Combustion Product Management Sites, EPRI Report Attachment D CD-MUSIC Reaction Database for Modeling Adsorption of Oxyanions on Iron Oxyhydroxides, EPRI Report Attachment E Attachment F Evaluation of Potential Groundwater Receptors Downgradient of CCR Management Facilities at Coal-Fired Power Plants, Memorandum dated November 5, The Use of Risk Assessment Results in the Regulatory Impact Analysis, Memorandum dated November 9, Attachment G Evaluation of Coal Combustion Product Damage Cases: Volume 1 Data Summary and Conclusions, EPRI Report Attachment H Evaluation of Coal Combustion Product Damage Cases: Volume 2 Case Summaries, EPRI Report EPRI Comments 8 November 18, 2010

13 Attachment I Geochemical Evolution of Fly Ash Leachate ph, White Paper dated November 14, Attachment J A Review of Agricultural and Other Land Application Uses of Flue Gas Desulfurization Products, EPRI Report Attachment K Summary of Demonstration Projects Using Coal Combustion Residuals as Engineered Structural Fill, EPRI Report Attachment L Environmental Evaluation for Utilization of Ash in Soil Stabilization, EPRI Report Attachment M Seismic Site Classification, Memorandum dated October 26, EPRI Comments 9 November 18, 2010

14 2 Costs of Subtitle C Regulation At several points in the Proposed Rule and Regulatory Impact Analysis (RIA), US EPA requests data and information on the costs associated with the proposed regulations (e.g., Fed. Reg. 75[118], 35159). In particular, cost information is requested on impacts at the power plant itself, as a result of Subtitle C rules. This section provides a summary of data on the engineering costs associated with Subtitle C rules developed for two model power plants, and an estimate of the national cost of Subtitle C regulations. Details of all assumptions and calculations are contained in Attachments A and B to this document (EPRI 2010a,b). 2.1 Basis for Cost Estimates The initial step in developing estimated costs was to identify modifications that power plants would need to make to comply with the Subtitle C regulations under the Proposed Rule, and to develop engineering cost estimates for those modifications. The estimates address only the incremental capital and operational costs of Subtitle C requirements above and beyond current practice. This evaluation includes costs incurred upstream of the disposal site, in other words those costs incurred within the power plant from point of generation (POG) through loading of the trucks, as well as incremental costs at the disposal site. Attachment A contains all of the assumptions and detailed cost data for individual components considered in this analysis. The data under this phase of the project contribute to the development of the national cost estimate described in Section 2.2 below. The assessment consisted of the following four steps: 1. Site visits to five power plants by the project team to identify the various systems that would be subject to the Subtitle C compliance. The project team consisted of an experienced power plant engineer, a hazardous waste compliance expert, and a CCR disposal site engineer. An important consideration in the site visits was evaluating the POG, discussed in further detail below. EPRI Comments 10 November 18, 2010

15 2. Site visit to a steel plant that generates electric arc furnace (EAF) dust, a K061 listed hazardous waste. The EAF dust is collected in a baghouse and is physically similar to fly ash. 3. Identification of operational/physical changes needed to comply with Subtitle C regulations, based on the site visits and knowledge of the Subtitle C regulations. 4. Estimation of costs for the required modifications. The POG for CCRs under Subtitle C is not specified in the Proposed Rule. It is stated in the Proposed Rule that CCRs destined for disposal are subject to Subtitle C, while CCRs destined for beneficial use are exempt. For fly ash, one possible POG would be the storage silo where the ash is loaded onto trucks and transported for either disposal or use applications. However, under RCRA, disposal may be an active decision (e.g., placing materials in a landfill for disposal) or passive (e.g., discharge, spilling, leaking solid waste or constituents of solid waste into the environment, air or water). 1 By this definition, passive disposal can occur in the plant area, for example, due to inadvertent releases from the ESP or baghouse or associated equipment, spillage from the boiler bottom into the bottom ash sump area, and tracking of FGD product near the doors of the processing/storage facility. Any CCR that is subsequently cleaned up in these areas is disposed. Therefore, for this analysis we interpret the POG at a power plant to be anywhere the potential exists for release of CCRs (intentional or inadvertent) that will eventually be discarded. This interpretation of the POG is consistent with the observations at the EAF dust facility visited by the project team. For example, the fabric filter compartment hoppers and EAF dust transport systems are totally enclosed in a building that meets RCRA standards. Windows and doors can be closed and sealed, and the building has a ventilating fan with a bag filter to maintain negative pressure, thus preventing losses of EAF dust from the building. Concrete floors are curbed, joints are sealed, and the floor is coated with an epoxy paint, tinted to make visible to the operations and maintenance (O&M) staff any dust that may escape the filters. The railcar loading area is completely enclosed, and facility doors are closed while the railcar is in the loading facility to minimize the potential for any dust releases CFR Definitions, Disposal means the discharge, deposit, injection, dumping, spilling, leaking, or placing of any solid waste or hazardous waste into or on any land or water so that such solid waste or hazardous waste or any constituent thereof may enter the environment or be emitted into the air or discharged into any waters, including ground waters. EPRI Comments 11 November 18, 2010

16 Due to size and space constraints, it would be extremely difficult and costly to modify a power plant to completely eliminate any releases of CCRs within the plant area. The approach priced in this analysis was to modify existing equipment and structures to serve as secondary containment, and to increase maintenance activities to respond to and correct inadvertent releases within the plant in a timely manner to meet compliance requirements under Subtitle C. It was assumed that costly modifications to the boiler itself would be prohibitive and unwarranted, and therefore were not considered in this analysis. For the cost analysis, the plant was divided into the seven subsystems summarized below (refer to Figure 2-1). The assumptions and costs for each of these areas are described in detail in Attachment A. Figure 2-1 Model 1600 MW Plant with Two 800 MW Units. EPRI Comments 12 November 18, 2010

17 Bottom Ash Handling. Upgrading the area below the boiler to serve as secondary containment. Enclosing the bottom ash truck loading area and providing negative pressure to prevent releases. Fly Ash and Economizer Ash Handling. Upgrading the ESP/FF building to serve as secondary containment. Enclosing the fly ash truck loading area. FGD Product Handling. Upgrading the dewatering, storage, and loading buildings to serve as secondary containment. Converting open conveyors to closed conveyors. Plant Site Runoff. This item was eventually eliminated as a consideration due to controls instituted in the other areas to minimize ash contact runoff. Disposal Site. Disposal site construction and operations costs were not included in this analysis; Subtitle C design requirements in the Proposed Rule are essentially the same as those proposed for Subtitle D and the designs currently used for new disposal cells, so the analysis assumed no incremental cost difference. Additional costs for Subtitle C at the disposal site that were included in this analysis were a RCRA waste pad as a staging area prior to disposal or use, extra security measures, additional leachate treatment, and increased operations costs. Wastewater Treatment. Consistent with the US EPA assumption under Subtitle C, it is assumed all CCR ponds will be eliminated under the Subtitle C option (Fed. Reg. 75[118], 35177). Costs under this area include: incremental costs of closing active CCR ponds to Subtitle C standards compared to Subtitle D, the cost of closing inactive CCR ponds that were not closed to Subtitle C standards 2, and wastewater treatment facilities to replace the function currently served by pond management of CCRs and CCR-contact water. Wastewater treatment was assumed to consist of standard physical/chemical treatment systems; no advanced treatment systems (e.g., biological) were considered. Operations and Administration (not shown on Figure 2-1). Includes all of the permitting and paperwork associated with Subtitle C compliance, groundwater monitoring, RCRA facility-wide investigation costs (but not corrective action costs), and increased maintenance activities. 2 The preamble states that inactive ponds will be required to meet Subtitle C closure standards if they do not currently meet those standards (Fed. Reg. 75[118], 35177). EPRI Comments 13 November 18, 2010

18 As noted above, corrective action costs resulting from the facility-wide investigation requirement under Subtitle C were not included. The need for corrective action will be site specific, and could vary significantly among plants. This is a potentially large additional compliance cost for some plants. The per-unit costs for conversion from wet to dry handling at plants that currently handle CCRs wet was estimated separately by the Utility Solid Waste Activities Group (USWAG, 2010). The USWAG estimates are used in the national cost estimate described in the next section. Cost estimates for each of the subsystems were derived for two model plant configurations: a 400 megawatt (MW) plant with two 200 MW units (small plant), and a 1600 MW plant with two 800 MW units (large plant). The cost estimates for each component of the subsystems were applied in the national cost estimate as presented in the next section. 2.2 National Cost Estimate This section presents the general methodology and data sources used to estimate the costs to the electric utility industry under the proposed Subtitle C regulatory option. Several data sources were used to construct a database with generating unit level and power plant level data for all of the potentially affected utilities in the U.S. with a generating capacity greater than 100 MW. Estimated costs, including those previously described in Section 2.1 and Attachment A, were then applied as appropriate based on specific unit and power plant configurations. This analysis does not represent the total cost of CCR management; it considers only the costs over baseline (i.e., current) costs that are attributable to Subtitle C regulation. Attachment B contains all of the assumptions and methodology used in developing the national cost estimate (EPRI, 2010b). The analysis assumes a 2012 final rule promulgation, with a five-year impoundment phase out. Under Subtitle C, states are expected to adopt the rules within 2 years, so an impoundment phase out date of 2019 is assumed. The analysis further assumes that capital expenditures on wet-to-dry conversion, wastewater treatment systems, and engineering upgrades would need to commence prior to the date when impoundments must stop receiving CCRs, to allow plants time to complete the retrofits. There is considerable concern among utilities with respect to the ability to complete all of the necessary permitting and capital modifications within the prescribed time horizon. For this analysis, to be consistent with the Proposed Rule, we assumed that all activities could be completed within the timeframe, and that no additional costs would be incurred due to permitting difficulties, accelerated EPRI Comments 14 November 18, 2010

19 implementation activities, and shortage in supply of materials and contractors. This approach is not intended to either confirm or refute the ability of the industry to comply with the specified schedule. The analytical model used to develop these cost estimates utilizes a Monte Carlo statistical model to account for parameter uncertainty in input cost components, and uncertainty in disposal decision by individual coal-fired power plants. Generating unit- and plant-specific compliance costs and disposal costs are calculated for each of the potentially regulated facilities. The analysis includes 377 plants; plants under 100 MW were not included because the EIA database does not maintain data for those plants. Cost assignments are based on unit and plant characteristics and configurations, ascertained from publicly available data and supplemented with plant-specific data derived from utility surveys. The plant compliance estimates are then aggregated to develop the total cost to the industry. Ranges of costs for specific scenarios represent the 5 th to 95 th percentile of the Monte Carlo runs. The primary data sources used to develop the generating unit and plant level data and estimated cost inputs include: Energy Information Agency (EIA) data, specifically Forms 860 and 923. Engineering cost estimates described in Section 2.1 and contained in Attachment A (EPRI, 2010a). Estimated costs for unit conversion to dry handling prepared by USWAG (2010). EPA coal ash surface impoundment survey data (EPA 2009b). EPRI survey data. This survey was conducted to gather specific information pertinent to the national cost estimate (Table 2-1); details are included in Attachment B (EPRI, 2010b). Table 2-2 contains the costs that were included and excluded from this analysis. It is important to note that landfill construction and operation costs were not included in the analysis. This was based on the assumption that even in the absence of the Proposed Rule, new disposal facilities would be built to standards similar to the Subtitle C/D design standard when the capacity of a current facility is exhausted. However, the Proposed Rule will require accelerated closure of some current facilities, and stranded costs related to lost capacity were included. Other potentially significant costs that were excluded from this analysis were state hazardous waste generator fees, the costs of remediation resulting from the required RCRA facility-wide investigation, and the cost of replacement power to compensate for outages and early retirement. EPRI Comments 15 November 18, 2010

20 Table 2-1 Overview of CCR Survey Questions. CCR Handling CCR Disposal Plant Facilities Number of units with wet (dry) bottom ash handling Number of units with wet (dry) fly ash handling Wet FGD solids separation Temporary storage of CCRs (buildings, sheds, stacker pads) Current disposal in on-site ponds and landfills Current use of commercial landfills Land availability for additional landfill capacity Subtitle C landfill siting restrictions (seismic, fault, floodplain, wetlands, state-level restrictions) Disposal choice under Subtitle C (on-site, off-site company owned or commercial) Wastewater treatment for FGD blowdown/purge Wastewater treatment for CCR contact water Buildings and enclosures for ESPs/baghouses and FGD dewatering equipment CCR solids conveyance to storage Table 2-2 Costs Included and Excluded in the National Cost Analysis. Included Capital Costs Included O&M Costs Excluded Costs Conversion to dry fly ash and bottom ash handling FGD solids dewatering for allponded systems Install tank-based wastewater treatment system (to replace impoundment function) Facility engineering to meet Subtitle C requirements (e.g., secondary containment, truck loading facilities with dust control, CCR storage buildings) RCRA Facility Investigation costs Financial assurance costs for closure and post-closure Financial assurance for third party liability coverage Incremental impoundment closure costs under Subtitle C regulation RCRA C closure of legacy impoundments Stranded costs associated with early pond closure Incremental costs for dry CCR handling O&M costs for wastewater treatment system RCRA reporting Personnel training General waste analysis and plan Groundwater monitoring and sampling Maintenance, spill prevention, and response Off-site disposal costs transportation costs and tipping fees for commercial disposal Power plants less than 100 MW Landfill construction costs Land acquisition costs RCRA remediation costs extremely facility-specific and would be dependent on RCRA Facility Investigation findings Cost of replacement power during outages or to compensate for early retirements Changes in revenue due to impacts to beneficial use markets State generator fees EPRI Comments 16 November 18, 2010

21 Three disposal options were considered under Subtitle C. The first was construction of an on-site (or near site, defined as within 5 miles of the power plant) Subtitle C landfill. The second scenario was an off-site utility-owned landfill, either at another plant or at a regional landfill serving multiple plants. The third scenario was disposal at a commercial hazardous waste landfill. EPRI survey data were used to identify the volume of CCRs that would be disposed for each of these options based on current projections by utilities: 67% of CCRs would be disposed in on-site landfills, 21% in off-site companyowned landfills, and 12% in commercial facilities. Those opting for off-site company-owned landfills were primarily larger utilities with multiple plants, while those opting for commercial facilities were primarily smaller and municipal plants, at least some of which currently use off-site non-hazardous commercial facilities. The analysis also considered three beneficial use scenarios that parallel the assumptions used by US EPA in the RIA: continued use of CCRs at current rates for encapsulated uses and mine placement, an 11% increase in use rate under the Proposed Subtitle C rule for these applications, and an 18% decrease in use rate for these applications under Subtitle C. Due to regulatory barriers imposed by the definition of beneficial use in the Proposed Rule as well as potential liabilities, we assume that unencapsulated uses would not continue at any significant level under the Subtitle C option. Mine placement was assumed to continue because the Proposed Rule does not address mine placement either from a disposal or beneficial use perspective. The assumed change in beneficial use was used to calculate the amount of CCRs that would need to be disposed under each scenario. Impacts to plant revenue from changes in beneficial use were not included in the analysis. It should be noted that there is considerable debate concerning the potential stigma effect of a Subtitle C listing on encapsulated uses. Because we have no independent data on the impact that Subtitle C would have on use rates, this approach is not intended to either confirm or refute the US EPA assumption regarding stigma, but simply to parallel their assumptions for easier comparison. The analysis also considered two points of generation: one at the truck loading facilities for the various CCRs, and one farther back in the plant at the points where the CCRs are initially collected. In addition, two discount rates were used, 7 percent and 3 percent. The analysis results are summarized in Table 2-3. The incremental costs associated with Subtitle C regulation ranged from $55 billion to $77 billion (present value over a 20-year period using a 7% discount rate). These costs do not reflect the total compliance costs, but rather the incremental costs above current and expected practice. The most significant incremental costs in the Subtitle C analysis EPRI Comments 17 November 18, 2010

22 were: conversion to dry handling at all facilities that currently have CCR ponds, plant upgrades (including additional operations and maintenance requirements), disposal costs (including off-site disposal), and replacement wastewater treatment costs. Table 2-3 Estimated Costs of Subtitle C Regulation for Three Beneficial Use Scenarios and Two Discount Rates. All Costs are Present Value (2010) in Billions of Dollars Over a 20-Year Period. Scenario 1 Incremental Costs for Subtitle C Option 2,3 (7% discount rate) Incremental Costs for Subtitle C Option 2,3 (3% discount rate) Scenario #1: Encapsulated Use Rate Unchanged Scenario #2: Encapsulated Use Decreases 18% Scenario #3: Encapsulated Use Increases 11% $55.31 $74.53 $78.92 $ $56.45 $76.84 $80.75 $ $54.66 $73.20 $77.74 $ The beneficial use scenarios mirror the US EPA assumptions in the Regulatory Impact Analysis. 2. Incremental cost of the Subtitle C regulation above baseline management costs. Landfill construction, operation, and closure are not included, except those costs unique to Subtitle C. 3. Based on 377 power plants. Plants less than 100 MW were not included. In this analysis, the beneficial use rate did not make a substantial difference in the outcome. Similarly, the choice of POG did not make a significant difference in the results (about a 5% difference), primarily because many of the designated upgrades designed for maintenance, spill prevention, and response in the plant would still be required even with a point of generation at the truck loading facility. A comparison of the costs under the alternate POG assumption is provided in Attachment B. The selection of discount rate does make a significant difference. The data the use of a 7% discount rate is consistent with US EPA and guidance by the Office of Management and Budget (OMB, 2003). However, OMB guidance also notes that in some circumstances a lower discount rate is warranted, and that regulatory costs should be reported for both discount rates. If a discount rate of 3% is EPRI Comments 18 November 18, 2010

23 used, the present value of the incremental cost range for the Subtitle C option increases to $78 billion to $114 billion (Table 2-3). 2.3 References Cited Note: All EPRI reports listed below are publicly available at no cost at EPRI, 2010a. Engineering and Cost Assessment of Listed Special Waste Designation of Coal Combustion Residuals Under Subtitle C of the Resource Conservation and Recovery Act. EPRI, Palo Alto, CA: EPRI, 2010b. Cost Analysis of Proposed National Regulation of Coal Combustion Residuals from the Electric Generating Industry. EPRI, Palo Alto, CA: Office of Management and Budget (OMB), Circular A-4: Regulatory Analysis. September 17. Available at Retrieved on November 5, US EPA, Information Request Responses from Electric Utilities. Available at Retrieved on December 3, USWAG, Cost Estimate for the Mandatory Closure of Surface Impoundments Used for the Management of Coal Combustion Byproducts at Coal-Fired Utilities. November 11, EPRI Comments 19 November 18, 2010

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25 3 Risk Assessments US EPA has published several supporting documents on the Federal Register docket [EPA-HQ- RCRA ] for the CCR Proposed Rule. Three of the reports listed on the docket provide information on the potential human and ecological risks associated with various coal ash disposal practices. US EPA requested comments on the risk assessments, and how the assessments should be used to inform the regulatory options (e.g., Fed. Reg. 75[118], & 35156). The Agency stated that results from these risk assessments, in part, are intended to support the selection of the appropriate regulatory option in the Proposed Rule. Specifically, we reviewed the following documents to respond to EPA s request for comments on these risk assessments and their potential use in selecting the appropriate regulatory option: Human and Ecological Risk Assessment of Coal Combustion Wastes (Health/Eco RA; US EPA, 2010) Draft Final Report: Non-Groundwater Pathways, Human Health and Ecological Risk Analysis for Fossil Fuel Combustion Phase 2 (NGP RA; US EPA, 1998) Inhalation of Fugitive Dust: A Screening Assessment of the Risks Posed by Coal Combustion Waste Landfills (Fugitive Dust RA, US EPA, 2009a) 3.1 Human and Ecological Risk Assessment EPRI provided detailed technical comments on the draft Health/Eco RA published by US EPA (US EPA, 2007a). The 2007 draft was also reviewed by a formal Peer Review Panel. We were pleased to see that US EPA responded to some of the comments provided by EPRI and the Peer Review Panel. However, despite the incorporation of the additional discussions, the modeling assumptions and results of the 2010 final RA do not differ in a substantive way from the previous draft. Therefore, many of the detailed comments EPRI made on the 2007 draft risk assessment are still applicable and are included by reference (EPRI, 2008). The following summarizes our overall comments on the 2010 Health/Eco RA; further details on specific issues are provided in the subsequent subsections. The Health/Eco RA is a very large and complex undertaking, encompassing several types of CCR management facilities across all regions of the United States. It broadly addresses a wide range of EPRI Comments 21 November 18, 2010

26 geologic, geographic, and climatic settings, as well as CCR types and management methods. The probabilistic approach used in this risk assessment is a scientifically sound approach, given the large number of variables and range in values that need to be considered for a national assessment. However, because of this broad application, the modeling by necessity requires considerable simplification, resulting in a high degree of variability and uncertainty in the results. The value of a broad analysis such as this lies in its application for qualitative comparisons. The Human/Eco RA provides information that can be used to qualitatively describe relative risks under different waste management scenarios; for example, results showing that composite lined sites pose less risk than unlined sites and the relative magnitude of the difference. However, due to the widely varying input data and large amount of uncertainty in some of the input data, the risk estimates cover a relatively broad range and the results are not specific enough for establishing reliable quantitative risk levels. Important factors adding significantly to the uncertainty are leachate input, groundwater transport (flow rates, soil types, and attenuation characteristics), location of receptors, likelihood and period of exposure, possible intervention (mitigation), and constituent toxicity. RA. The sections below provide additional specific comments on certain aspects of the Human/Eco Leachate Input Data Leachate input distributions to the groundwater transport model are critical in defining the groundwater concentrations and therefore risk at receptor locations. US EPA used a tiered methodology to establish leachate input distributions: field leachate/porewater was considered the best data source, and the Synthetic Precipitation Leaching Procedure (SPLP) and Toxicity Characteristic Leaching Procedure (TCLP) were the lowest tier choices (Table A-4 in the 2010 Health/Eco RA). However, SPLP and/or TCLP data were available for the highest percentage of sites in the US EPA database. Where multiple results were available for the same tier for a site, the one yielding the higher concentration was selected as the preferred data source. We agree that field leachate/porewater is the most reliable indicator of actual leachate concentrations. As noted in Table A-4 referenced above, US EPA only had field leachate/porewater for a few sites, and in the Proposed Rule US EPA requested additional leachate data to enhance their database (Fed. Reg. 75[118], and 35222). EPRI, with support from the Department of Energy, completed a large field scale leachate characterization project in Eighty-one field leachate samples were EPRI Comments 22 November 18, 2010

27 collected from 29 power plant sites using standardized procedures. The samples were analyzed for over 30 constituents, including speciation for arsenic, selenium, chromium, and mercury. Attachment C is the final report containing the leachate sampling results (EPRI, 2006a). We believe these data represent the largest single source of CCR field leachate data assembled using standardized sampling and analysis procedures. These data were provided to US EPA, although our study was likely completed too late to be included in the risk assessment, which was largely completed in In addition to providing the attached data, we are willing to work with US EPA to expand and enhance the field leachate database to better characterize actual source concentrations at these sites. In reviewing the leachate database on the docket that was used for the Human/Eco RA, we found several potential issues that merit attention, given the importance of leachate data input to the RA modeling. These are summarized below Sites Used for Generating Leachate Data Input In reviewing the database used to develop leachate data inputs, we found potential issues with some of the sites referenced. Of the 152 site averages used, 28 (18%) were listed as being from coal mine sites. There are several potential technical issues associated with use of these data for the CCR RA. First, CCR management in mines was not modeled and is not covered in the proposed rule. If these were field samples collected from mine sites, then they should not be used in this analysis because mines present much different field leaching conditions than the CCR landfills and impoundments modeled. Second, there are potential data issues related to the sources of ash managed in the mines, and how representative they are of the utility CCR managed in landfills and impoundments. If they were fresh CCR samples (e.g., collected before placement in the mine), then they may be from the same plants as other samples identified in the database and should have been included in those averages. Finally, US EPA noted that some of the mine samples (from Freeman United Mining) came from sources other than power plants and that these samples had elevated lead concentrations (Fed. Reg. 75[118], 35146). Our review of the Freeman United samples also indicated relatively high concentrations of cadmium and cobalt in these samples (the median of the Freeman samples was a factor of 2 or more higher than the median of the entire RA dataset). Detailed information on the boilers and ash collection systems in place at these ash sources is needed to EPRI Comments 23 November 18, 2010