IEc Draft: May 2005 1 See " Human Health and Ecological Risk Assessment Support to the Development of Technical Standards for Emissions from Combustion Units Burning Hazardous Wastes: Background Document" November 1998.

2 We did not include an analysis to assess the potential magnitude of property value benefits caused by the MACT standards due to limitations of the benefits transfer approach and because property value benefits likely overlap with some human health and ecological benefits. As a result, including property value benefits may result in doublecounting The benefits assessment also does not examine how secondary impacts such as emissions from increased coal use at combustion sources that stop burning hazardous waste as fuel may result in human health and ecological damages.

6 1 BENEFITS ASSESSMENT CHAPTER 6 ______________________________________________________________________________

This chapter presents the benefits assessment for the HWC MACT replacement standards. To evaluate the benefits resulting from emissions reductions at hazardous waste combustion facilities, we extrapolate from results presented in EPA's 1998 multiple pathway human health and ecological risk assessment. 1 Based on the results of that risk assessment, we estimate benefits incremental to those achieved under the 2002 Interim Standards. 2 In addition, this chapter briefly discusses how the HWC MACT replacement standards may affect waste minimization activities at hazardous waste combustion facilities.

The chapter is organized into six sections:

Risk Assessment Overview: Provides a brief summary of the methodology and key results from the multiple pathway risk assessment which forms the basis for the human health and ecological benefits assessment.

Human Health Benefits Analysis: Describes the approach for characterizing human health benefits from the risk results and presents results of our health benefits analysis. Where possible, we assign monetary values to risk reductions using economic valuation techniques. We also describe IEc Draft: May 2005 6 2 benefits to sensitive sub populations in quantitative, non monetary terms.

Visibility: Describes the approach for characterizing visibility improvements and presents estimates of visibility related benefits. We assign monetary values to these improvements using economic valuation techniques.

Ecological Benefits Analysis: Explains the methodology and results from the ecological benefits assessment conducted in support of the 1999 Standards and describes the expected ecological benefits of the replacement standards.

Waste Minimization Benefits: Describes the benefits, if any, that the HWC MACT replacement standards may have on waste minimization practices.

Conclusions: Summarizes key findings from the benefits assessment.

This benefits analysis builds upon the results and discussions presented in the 1999 Assessment and the 1999 Addendum. These documents are cited as source material for the current analysis because they generally provide a reasonable approximation of the 2002 Interim Standards baseline. However, it is important to note that the 2002 Interim Standards, not the 1999 standards, represent the baseline for the HWC MACT replacement standards. This Assessment clearly indicates those instances where we use the 1999 analyses to approximate the 2002 Interim Standards baseline.

It is also important to note that the benefits analysis is based on trial burn emissions data. As explained in Chapter 3, the characteristics of waste fed during normal operations may differ significantly from the characteristics of waste fed during trial burns. Facilities often " spike" the waste feed during trial burns with high levels of metals, chlorine, and mercury. Consequently, the emissions estimates supporting the benefits analysis are likely to overestimate " typical" emissions. Therefore, we may overstate true benefits. Conversely, if several systems stop burning hazardous waste as a result of the replacement standards, we may underestimate benefits associated with such systems. IEc Draft: May 2005 3 Although we extrapolate benefits from the estimates presented in the 1999 Assessment and the 1999 Addendum, the 2002 Interim Standards serve as the baseline of our analysis. The 2002 Interim Standards are generally similar to the standards examined in the 1999 Assessment and Addendum; therefore, these 1999 analyses serve as a reasonable approximation of the 2002 Interim Standards baseline.

4 See " Human Health and Ecological Risk Assessment Support to the Development of Technical Standards for Emissions from Combustion Units Burning Hazardous Wastes: Background Document" November 1998.

6 3 BENEFITS QUANTIFICATION OVERVIEW To quantify the benefits of the HWC MACT replacement standards, we extrapolate from benefits associated with the 1999 Standards, as estimated in the 1999 Assessment. 3 This section provides an overview of the methods used to extrapolate the incremental benefits of the replacement standards from those estimated for the 1999 standards. Ideally, our analysis would reflect the risk reductions associated with the 2002 Interim Standards rather than the 1999 Standards. However, EPA did not conduct a separate risk assessment for the Interim Standards. Because the Interim Standards for incinerators, cement kilns, and lightweight aggregate kilns are nearly the same as the 1999 Standards, risk reductions resulting from the Interim Standards are likely to be similar in magnitude to those associated with the 1999 standards. Therefore, we assume that the benefits estimates in the 1999 Assessment are a reasonable proxy for benefits realized under the 2002 Interim Standards.

For the 1999 Assessment, we estimated the avoided incidence of mortality and morbidity associated with reductions in particulate matter ( PM) emissions. 4 Morbidity effects included respiratory and cardiovascular illnesses requiring hospitalization, acute and chronic bronchitis, acute upper and lower respiratory symptoms, minor restricted activity days ( MRADs), and work loss days ( WLDs). The risk assessment estimated risk reductions for each of these health endpoints for 16 spatial zones surrounding each facility, using concentration response functions derived from the epidemiological literature and population data for each spatial zone. These results were also based on estimates of ambient PM concentrations developed for the analysis.

For the current assessment we scaled the results of the 1999 Assessment to reflect current conditions and emission reductions achieved under the HWC MACT replacement standards. Since the 1999 Assessment was completed, several facilities have either closed or stopped burning hazardous waste; therefore, we incorporate such changes in the HWC MACT universe into our estimates of the benefits associated with the replacement standards. Similarly, the emissions reductions expected under the replacement standards are different than those associated with the 1999 standards, even for facilities that still burn hazardous waste. Our analysis of the replacement standards accounts for these differences. It is important to note that the benefits presented here and in the 1999 Assessment represent only a portion of the benefits associated with this rule, as inadequate information is available to measure many of the potential human health and ecological benefits of the rule. IEc Draft: May 2005 5 OMB guidance recommends that federal agencies conduct probabilistic assessments of the benefits associated with new regulation. Office of Management and Budget. Informing Regulatory Decisions: 2003 Report to Congress on the Costs and Benefits of Federal Regulations and Unfunded Mandates on State, Local, and Tribal Entities. 2003.

6 " Human Health and Ecological Risk Assessment Support to the Development of Technical Standards for Emissions from Combustion Units Burning Hazardous Wastes: Background Document  Final Report," November 1998.

7 The Agency expects that hazardous waste burning kilns that are able to use feed control to achieve emissions reductions will also generate cement kiln dust ( CKD) with a lower toxicity than prior to feed control ( in particular, lower SVM content) ( USEPA " Selection of MACT Standards and Technology," Chapter 12 of Volume 3 Technical Support Document for HWC MACT Standards, July 1999.) The risk assessment did not address the potential human health and ecological benefits associated with reduced toxicity CKD.

8 A less detailed screening level analysis was used in the 1999 Assessment to identify the potential for ecological risks.

9 For a more detailed discussion of the land use characterization, see: Zachary Pekar and Tony Marimpietri,

" Description of Methodologies and Data Sources Used in Characterizing Land Use ( including Human/ Livestock Populations), Air Modeling Impacts, and Waterbody/ Watershed Characteristics for HWC Study Areas," Memorandum, Prepared for David Layland, U. S. Environmental Protection Agency, 27 January 1998.

6 4 The benefits estimates in this assessment are presented as point estimates rather than in probabilistic terms. 5 Although probabilistic estimates would provide valuable information about the uncertainty associated with the benefits of the HWC MACT replacement standards, probabilistic analysis was not amenable to our methodology, as the 1999 Assessment did not express benefits in probabilistic terms. In certain cases, however, we present monetized estimates as a range to reflect uncertainty in the value of avoided adverse health impacts.

RISK ASSESSMENT OVERVIEW The basis for the benefits analysis in the 1999 Assessment was a multiple pathway risk assessment developed by the Economics, Methods and Risk Analysis Division in EPA's Office of Solid Waste. This risk assessment was designed to estimate baseline risks from hazardous waste combustion emissions, as well as expected risks after the 1999 MACT standards were implemented. 6 This section provides an overview of the risk assessment, which analyzed both human health and ecological risks that result from direct and indirect exposure to emissions from facilities that burn hazardous waste. 7 As part of this effort, EPA conducted a multiple pathway analysis modeling both inhalation and ingestion pathways was used to estimate human health risks. 8 The risk assessment used a statistically based stratified random sampling approach in which 76 hazardous waste combustion facilities and their site specific land uses and environmental conditions were characterized. 9 The facilities randomly selected for the study included: 43 on site incinerators, 13 IEc Draft: May 2005 10 According to the risk assessment, the random sample of 65 facilities ensures that the probability of modeling at least one high risk facility is 90 percent. The other 11 combustion facilities were selected for the risk assessment at Proposal. Because these 11 facilities were not selected at random, they are handled differently than the 65 randomly selected facilities in extrapolating risks to reflect the universe of facilities.

11 PM is not evaluated in the screening for ecological risks. Also, the national risk assessment did not include an assessment of the risk posed by non dioxin products of incomplete combustion ( PICs) due to the lack of sufficient emission measurements.

12 Includes divalent mercury ( via ingestion), elemental mercury ( via inhalation), and methylmercury ( via ingestion). We recognize that these chemicals are not all HAPs; however, the risk assessment analyzed all chemical constituents covered by the rule for which sufficient data were available. Both chromium ( III) and chromium ( VI) were evaluated in the risk assessment.

13 The methodology used to develop the eco toxicological criteria is largely a product of the ecological risk assessment work conducted to support the development of the Hazardous Waste Identification Rule for process waste.

6 5 commercial incinerators, 15 cement kilns, and five lightweight aggregate kilns. 10 The current Assessment adjusts the estimates from the 1999 Assessment to project the human health benefits of the replacement standards.

The risk assessment evaluated health impacts associated with dioxins and furans, selected metals, and PM. 11 The selected metals modeled in the risk assessment included the following: antimony, arsenic, barium, beryllium, cadmium, chromium copper, cobalt, lead, manganese, mercury, nickel, selenium, silver, and thallium. 12 The risk assessment modeled the fate and transport of the emissions of these pollutants to estimate concentrations in soils, air, surface waters, and sediments. To assess human health risks, concentrations of each pollutant were converted to estimated doses for exposed populations using exposure factors such as inhalation and ingestion rates. The risk assessment calculated cancer and non cancer risks using these doses, if the appropriate health benchmarks were available.

This Assessment compares the ecological benefits that may be associated with the replacement standards with those achieved under the 1999 Standards, largely based on differences in the emissions reductions achieved under each set of regulations. In the 1999 Assessment, soil, surface water and sediment concentrations were compared to eco toxicological criteria representing protective threshold values to assess potential ecological risks. 13 Because these criteria were based on de minimis ecological effects and thus represented conservative values, an exceedence of the ecotoxicological criteria did not necessarily indicate ecological damage; it simply suggested that potential damages could not be ruled out.

To characterize the non cancer risks to the populations listed above, the 1999 risk assessment divided the area surrounding each modeled combustion facility into 16 polar grid zones, as illustrated IEc Draft: May 2005 6 6 Exhibit 6 1 DIAGRAM OF 16 SECTOR POLAR BASED GRID USED IN THE RISK ASSESSMENT Waterbody ( lake)

One of 16 sectors U. S. Census Block Group 0 2 km ring 2 5 km ring 5 10 km ring 10 20 km ring in Exhibit 6 1. For each zone, risk estimates were developed for different age groups and receptor populations ( e. g., 0 5 year old children of subsistence fishers). This approach was used because of geographic and demographic differences across polar grid zones. Thus, individual risk results were aggregated across the 16 zones associated with each facility and weighted by the population of each zone to estimate risk for individuals in the affected area. An additional Monte Carlo analysis was conducted to incorporate variability in exposure factors such as inhalation and ingestion rates.

HUMAN HEALTH BENEFITS This section describes in greater detail our approach for characterizing human health benefits associated with the HWC MACT replacement standards. Based on the results of the 1999 Assessment, we identify those pollutants for which emission reductions are expected to improve human health or the environment. We then summarize the relevant results from the risk assessment for the pollutants of concern, expressing results in terms of the avoided incidence of each health endpoint. Where possible, we assign monetary values to these benefits through benefits transfer.

Our methods for assessing the human health benefits of the HWC MACT replacement standards vary by health endpoint. To simplify this discussion, we divide our description of methods into two sections   one focusing on benefits from cancer risk reductions and another focusing on IEc Draft: May 2005 14 Cancer incidence estimates were based on direct and indirect exposure pathways for all non subsistence receptors, excluding recreational anglers. Population risks could not be calculated for recreational anglers because detailed population data were not available for this receptor population.

6 7 benefits from non cancer risk reductions. We divide the discussion in this way because the interpretation of risk reductions for carcinogenic pollutants is different than the interpretation of benefits associated with other pollutants. As explained above, for both cancer and non cancer benefits, we focus on population risks because these results form the basis for assessing the total benefits of the HWC MACT replacement standards. In general, these results encompass the entire population, although risk reductions for some pollutants, such as lead, only affect children. In these cases, we focus our analysis on individuals 19 years of age and younger.

Approach for Assessing Benefits from Cancer Risk Reductions Our approach for evaluating cancer risk reductions varies by pollutant. For dioxin, we extrapolate from results presented in the 1999 Assessment, proportionately adjusting the benefits estimate in the 1999 Assessment to reflect the emissions reduction achieved under the replacement standards. To make this proportional adjustment, we assume a constant number of avoided cancer cases per gram of reduced dioxin emissions. This adjustment can be expressed as follows:

B c, replacement=( E dioxin, replacement/ E dioxin, 1999) x B c, 1999 where B c, replacement = Cancer related benefits under the replacement standards, E dioxin, replacement = Reduction in dioxin emissions under the replacement standards, E dioxin, 1999 = Reduction in dioxin emissions under the 1999 Standards, and B c, 1999 = Cancer related benefits under the 1999 Standards.

For other carcinogenic pollutants, adequate data were not available to extrapolate from results presented in the 1999 Assessment. To characterize reductions in cancer risk for these pollutants, we review results from the 1999 Assessment and describe how cancer risk reductions for these pollutants may be different under the replacement standards.

Summary of Cancer Risk Analysis in the 1999 Assessment The 1999 Assessment used a two tiered approach for assessing benefits associated with reduced cancer risk. First, the risk assessment estimated cancer risk reductions for all non subsistence receptors in the vicinity of each combustion facility. These risk reduction estimates were derived from median individual risk values and population data for the non subsistence population. 14 Carcinogens in the risk assessment included dioxins/ furans, arsenic, beryllium, cadmium, chromium ( VI), and nickel. For the second tier of the analysis, the risk assessment estimated cancer risk IEc Draft: May 2005 15 In a December 30, 1997 benefits methodology memorandum, we noted that summing these estimates may pose the potential for double counting, considering that dioxin contaminated food ingestion is also evaluated on the local level ( Industrial Economics, Incorporated, Social Science Discussion Group. Handbook for Non Cancer Valuation: Draft. Prepared for U. S. EPA, 1997, as cited in U. S. EPA, Assessment of the Potential Costs, Benefits, and Other Impacts of the Hazardous Waste Combustion MACT Standards: Final Rule, Office of Solid Waste, July 1999). However, if we make the assumption that most of the agriculture products produced within 20 kilometers of the facility are consumed outside the local area, we then minimize the double counting potential. A follow up phone call with EPA and Research Triangle Institute, the contractor that prepared the Combustion Risk Assessment, confirmed that this in fact is a reasonable assumption.

16 The benefits discussion that follows in the rest of this paragraph is adapted from EPA, Regulatory Impact Analysis of the Final Industrial Boilers and Process Heaters NESHAP: Final Report, February 2004.

6 8 reductions associated with the ingestion of dioxin contaminated foods grown or raised near combustion facilities but distributed nationwide. The risk assessment then calculated total cancer risk reductions by summing the avoided cancer cases estimated for each tier of the analysis. 15 That is,

Total cancer risk reductions = Avoided cases in communities near combustion facilities + Avoided cases due to reduced dioxin in the national food supply.

Approach for Assessing Benefits from Non Cancer Risk Reductions Similar to our analysis of reduced cancer risk, our analysis of reduced risk for other health effects varies by pollutant. For particulate matter, we estimate benefits associated with avoided morbidity and mortality impacts based on PM emissions reductions expected under the HWC MACT replacement standards and the results of the 1999 Assessment. For lead and mercury, sufficient data was not available to extrapolate results from the 1999 Assessment. To evaluate reduced health risks associated with these pollutants, we review the results from the 1999 Assessment and describe in qualitative terms how such risks may be different under the replacement standards.

Benefits from Reduced Exposure to Particulate Matter Epidemiological studies have linked PM ( alone or in combination with other air pollutants) to a series of adverse health effects. 16 PM can accumulate in the respiratory system and aggravate health problems such as asthma, or it can penetrate deep into the lungs and lead to even more serious health problems. These health effects include premature death, respiratory symptoms and disease, diminished lung function, and weakened respiratory tract defense mechanisms. Children, the elderly, and people with cardiopulmonary disease, such as asthma, are most at risk from these health effects. IEc Draft: May 2005 17 U. S. EPA, Regulatory Impact Analysis of The Final Industrial Boilers and Process Heaters NESHAP: Final Report, February 2004.

18 U. S. EPA, Final Regulatory Impact Analysis of the Clean Air Interstate Rule, March 2005.

19 Research Triangle Institute, Human Health and Ecological Risk Assessment Support to The Development of Technical Standards for Emissions from Combustion Units Burning Hazardous Wastes: Background Document, prepared for U. S. EPA, Office of Solid Waste, July 1999.

20Pope, C. A. 3rd, M. J. Thun, M. M. Namboodiri, D. W. Dockery, J. S. Evans, F. E. Speizer, and C. W. Heath, Jr. 1995. Particulate air pollution as a predictor of mortality in a prospective study of U. S. adults. American Journal of Respiratory and Critical Care Medicine, 151: 669 674, as cited in Research Triangle Institute, op. cit.

21 Krewski D., R. T. Burnett, M. S. Goldbert, K. Hoover, J. Siemiatycki, M. Jerrett, M. Abrahamowicz, and W. H. White. 2000. Reanalysis of the Harvard Six Cities Study and the American Cancer Society Study of Particulate Air Pollution and Mortality. Special Report to the Health Effects Institute, Cambridge MA, July 2000.

22 Pope, C. A., III, R. T. Burnett, M. J. Thun, E. E. Calle, D. Krewski, K. Ito, and G. D. Thurston. 2002. " Lung Cancer, Cardiopulmonary Mortality, and Long term Exposure to Fine Particulate Air Pollution." Journal of the 6 9 Since performing the risk assessment for the 1999 Assessment, EPA has updated its methods for evaluating human health benefits to reflect recent advances in air quality modeling and human health benefits modeling. To estimate PM exposure for the 1999 risk assessment, the Agency used the Industrial Source Complex Model Short Term Version 3 ( ISCST3). More recent EPA benefits analyses have used more advanced air quality models. For example, the Agency's assessment of the industrial boilers and process heaters NESHAP used the Climatological Regional Dispersion Model ( CRDM), which uses a national source receptor matrix to estimate exposure associated with PM emissions. 17 Similarly, the Agency's analysis of the final Clean Air Interstate Rule ( CAIR) used the Community Multi Scale Air Quality Model( CMAQ), which also accounts for the long range transport of particles. 18 In contrast, ISCST3 modeled exposure only within a 20 kilometer radius of each emissions source for the 1999 risk assessment. 19 To the extent that PM is transported further than 20 km from each emissions source, the 1999 risk assessment may have underestimated PM exposure. In addition, to estimate exposure in the 1999 risk assessment, EPA used block group data from the 1990 Census. More recent studies use data from the 2000 Census.

More recent EPA benefits analyses also apply a different concentration response function for PM mortality than that used for the 1999 risk assessment. In 1999, EPA used the concentrationresponse function published by Pope, et al. in 1995.20 Since that time, health scientists have refined estimates of the concentration response relationship, and EPA has updated its methodology for estimating benefits to reflect these more recent estimates. In its regulatory impact analysis of the nonhazardous boiler MACT standards, EPA used the Krewski, et al. re analysis of the 1995 Pope study to estimate avoided premature mortality. 21 In addition, EPA's regulatory impact analysis of the Clean Air Interstate Rule applies the latest reanalysis of the cohort analyzed in the 1995 Pope study ( Pope, et al., 2002). 22 The 2002 Pope study estimates a relative risk factor ( 1.06) lower than those estimated IEc Draft: May 2005 American Medical Association. 287: 1132 1141.

23 Work loss days and minor restricted activity days do not necessarily affect a worker's income and do not generally require hospitalization. Both, however, result in lost economic productivity and consequently, a loss to society.

24 To account for the increase in population since the 1990 census was taken, we also adjusted the avoided incidence estimates by the ratio of the population at the national level ( corresponding to the concentration response function) for the year 2000 census vs. the 1990 census.

6 10 in the Krewski and 1995 Pope analyses ( 1.18 and 1.17, respectively). To the extent that the 2002 Pope study is more accurate than the two earlier studies, we may over estimate the mortality benefits of the HWC MACT replacement standards.

To assess benefits from reduced exposure to particulate matter in 1999, we first estimated the number of excess mortality and morbidity cases in the baseline and under various 1999 MACT standard scenarios. Morbidity impacts included the following:

upper respiratory symptoms,

lower respiratory symptoms,

chronic bronchitis,

acute bronchitis,

hospital admissions associated with cardiovascular disease,

hospital admissions associated with respiratory illness,

work loss days, and

minor restricted activity days ( MRAD). 23 We then subtracted the number of cases post MACT from the number of cases in the baseline to determine potential avoided deaths and morbidity impacts.

To assess the benefits of the HWC MACT replacement standards, we adjusted the avoided incidence estimates from the 1999 Assessment to reflect PM emissions reductions under the replacement standards ( incremental to the 2002 Interim Standards) and changes in the HWC MACT universe since the 1999 Assessment was completed. For cement kilns, lightweight aggregate kilns, and incinerators, we multiply the 1999 benefits estimate by two factors specific to each source category: an emissions factor and a sources factor. The emissions factor is the ratio of the emissions reductions to be achieved under the replacement standards to the emissions reductions under the 1999 Standards. Similarly, the sources factor is the ratio of the number of sources in each category ( e. g., cement kilns) in 2005 and the number of sources in each category in 1999.24 For liquid boilers, solid boilers, and hydrochloric acid production furnaces, we extrapolated from the 1999 incinerator results using a similar approach, except that we used an exposed population factor ( i. e., the ratio of the population currently exposed to boiler and HCl production furnace emissions to the population IEc Draft: May 2005 25 Based on the population estimated in the 1999 Assessment.

26 U. S. EPA, The Benefits and Costs of the Clean Air Act, 1970 to 1990, October 1997.

27 Benefits estimate was converted to 2002 dollars using the GDP Deflator.

6 11 exposed to incinerator emissions in 1999) instead of a sources factor.

We estimated the exposed populations for hazardous waste burning boilers and HCl production furnaces using the same GIS methods as the 1999 Assessment ( e. g., a 16 sector overlay). Nonetheless, the extrapolated estimates are subject to additional uncertainty, especially for solid fuelfired boilers and HCl production furnaces because they are limited in number and may be poorly represented by the incinerator facilities analyzed in the 1999 Assessment.

Benefits from Reduced Exposure to Lead The primary health effect associated with chronic exposure to lead is damage to the central nervous system. Children are particularly sensitive to the effects of lead and excess exposure can affect a child's nervous system and cognitive development. The HWC MACT replacement standards will reduce lead emissions by approximately 2.5 tons per year under the Agency Preferred Approach, or less than 0.01 pounds per person, based on the population included in the 1998 risk assessment. 25 The 1999 standards were expected to reduce lead emissions by 89 tons per year, or 0.17 pounds per person, and were expected to annually reduce cumulative lead exposures for two to seven children age 0 5 from above to below 10 µ g/ dL. The annual benefits associated with the replacement standards are expected to be more modest, reducing cumulative lead exposures from above to below 10 µ g/ dL for fewer than two to seven children age 0 5 per year.

EPA's retrospective analysis of the Clean Air Act, Benefits and Costs of the Clean Air Act, 1970 to 1990, monetizes the benefits of reduced lead emissions by relating high blood lead levels with adverse IQ impacts. 26 The analysis estimates annual benefits of approximately $ 41 billion associated with reduced lead emissions of 234,000 tons per year. 27 However, the relationship between reduced lead emissions and IQ improvements is not linear, so we cannot extrapolate from these results to estimate benefits associated with reduced lead emissions under the HWC MACT replacement standards. IEc Draft: May 2005 28 The benefits discussion that follows in the rest of this paragraph is adapted from EPA, Regulatory Impact Analysis of the Final Industrial Boilers and Process Heaters NESHAP: Final Report, February 2004. Additional information related to the health effects associated with mercury are provided in chapter 9 of this report.

29 EPA, Regulatory Impact Analysis of the Final Industrial Boilers and Process Heaters NESHAP: Final Report, February 2004.

30U. S. EPA, Regulatory Impact Analysis of the Clean Air Mercury Rule: Final Report, March 2005.

6 12 Benefits from Reduced Exposure to Mercury Reduced mercury emissions under the HWC MACT replacement standards may generate a range of human health benefits. 28 A reduction in mercury emissions is likely to reduce the deposition of mercury in lakes, rivers, and streams, which will subsequently reduce bioaccumulation of methylmercury in fish. Since consumption of fish containing methylmercury may cause adverse health effects, reductions in the bioaccumulation of methylmercury in fish could lead to human health benefits.

When humans consume fish containing methylmercury, the ingested methylmercury is absorbed into the blood and distributed to tissue throughout the body. In pregnant women, methylmercury can be passed on to developing fetuses and lead to a number of neurological disorders for these unborn children. These disorders may lead to learning disabilities and developmental problems likely to adversely affect children's future earnings potential. These effects can occur at doses that do not affect the mother. In addition, children who consume fish containing methylmercury may develop neurological disorders as well. A more detailed description of the benefits associated with reduced mercury exposure is presented in EPA's regulatory impact analysis of the non hazardous boiler MACT standards and in the Agency's regulatory impact analysis of the Clean Air Mercury Rule. 29,30 Since the numerical relationship between mercury exposure and the health effects described above is highly uncertain, we do not quantify the benefits associated with reduced mercury emissions under the HWC MACT replacement standards. Instead, we present a qualitative discussion of the benefits that might result from the replacement standards for mercury.

Benefits from Reduced Exposure to Chlorine This analysis does not quantify the benefits associated with reductions in chlorine emissions. The HWC MACT replacement standards are expected to reduce total chlorine emissions, a combination of hydrogen chloride ( HCl) and chlorine gas ( Cl 2) emissions, by approximately 107 to 127 tons per year for the Floor options and 107 tons per year for the Agency Preferred Approach ( Exhibit 6 3). Hydrogen chloride is corrosive to the eyes, skin, and mucous membranes. Acute IEc Draft: May 2005 6 13 inhalation can cause eye, nose, and respiratory tract irritation and inflamation, and pulmonary edema. Chronic occupational inhalation has been reported to cause gastritis, bronchitis, and dermatitis in workers. Long term exposure can also cause dental discoloration and erosion. No information is available on the reproductive or developmental effects in humans. Chlorine gas inhalation can cause bronchitis, asthma, swelling of the lungs, headaches, heart disease, and meningitis. Acute exposure causes more severe respiratory and lung effects and can result in fatalities. No information is available on the reproductive or developmental effects in humans. The HWC MACT replacement standards are expected to reduce chlorine exposure for people in close proximity to hazardous waste combustion facilities, and are therefore likely to reduce the risk of all of these health effects among those populations. However, without detailed exposure modeling it is not possible to quantify the benefits of reduced chlorine emissions under the HWC MACT replacement standards.

Valuation of Human Health Benefits To measure the value of the human health benefits associated with the HWC MACT replacement standards, we assign a monetary value to avoided cases of each health endpoint included in the risk assessment. In general, two types of estimates can be used to characterize the value of avoiding an adverse health impact: willingness to pay ( WTP) estimates and cost of illness ( COI) estimates. Willingness to pay estimates reflect the amount a person is willing to pay to avoid an adverse health effect, while cost of illness estimates reflect the average medical costs associated with the effect ( e. g., hospitalization costs, pharmaceutical expenditures, etc.). Although the two are based on different concepts, they overlap with each other, as a person's willingness to pay to avoid an adverse health effect is likely to include avoided medical costs. For the purposes of estimating the benefits to society of reducing the incidence of negative health impacts, WTP estimates are more appropriate than COI estimates because they reflect factors such as pain and suffering not captured by cost of illness estimates. For some health effects, however, a willingness to pay estimate is not available, in which case a cost of illness estimate may be used.

It is important to note that WTP is likely to vary with changes in income. As real income rises, individuals are generally willing to pay more to avoid adverse health effects. Similarly, if income falls, WTP is also likely to decline. Therefore, when using WTP estimates to assess the value of avoided health impacts, it is important to ensure that the WTP estimates used in the analysis are consistent with the study's income assumptions. IEc Draft: May 2005 31 Mrozek, J. R., and L. O. Taylor. 2002. " What Determines the Value of Life? A Meta Analysis." Journal of Policy Analysis and Management 21( 2): 253 270 and Viscusi, V. K., and J. E. Aldy. 2003. " The Value of a Statistical Life: A Critical Review of Market Estimates Throughout the World." Journal of Risk and Uncertainty 27( 1): 5 76.

32 U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005, Table 4 11.

33 The regulatory impact analysis for the Clean Air Interstate Rule presents central VSL estimates consistent with 1990 income ($ 5.5 million, in 1999 dollars) and 2010 income ($ 6.0 million, in 1999 dollars). To estimate a central VSL value that reflects income in 2005, we interpolate between these two values, which yields a VSL estimate of $ 5.9 million ( in 1999 dollars). Adjusting for inflation with the GDP deflator, this estimate is $ 6.2 million in year 2002 dollars. The CAIR RIA provides low and high VSL values consistent with income in 1990 but does not provide low and high VSL values reflecting income projections for 2010. We estimated these values by assuming that the proportional relationship between the central, low, and high VSL values remains constant as income changes.

34 Physician charges for hospital admissions come from Abt Associates, Incorporated, The Medical Costs of Five Illnesses Related to Exposure to Pollutants, Prepared for U. S. EPA, Office of Pollution Prevention and Toxics, Washington, DC, 1992, as cited in U. S. EPA, Assessment of the Potential Costs, Benefits, and Other Impacts of the Hazardous Waste Combustion MACT Standards: Final Rule, Office of Solid Waste, July 1999. Hospital charge estimates for these illnesses are from A. Elixhauser, R. M. Andrews, and S. Fox, Agency for Health Care Policy and Research ( AHCPR), Center for General Health Services Intramural Research, U. S. Department of Health and Human Services, Clinical Classifications for Health Policy Research: Discharge Statistics by Principal Diagnosis and Procedure, 1993, as cited in U. S. EPA, Assessment of the Potential Costs, Benefits, and Other Impacts of the Hazardous Waste Combustion MACT Standards: Final Rule, Office of Solid Waste, July 1999. Estimates of the opportunity cost of time spent in the hospital is from U. S. Environmental Protection Agency, The Benefits and Costs of the Clean Air Act, 1970 to 1990, October 1997, I11 I12.

6 14 To estimate the value of avoided cases of premature mortality under the replacement standards, we apply central, low, and high WTP estimates of the value of a statistical life ( VSL) derived from two meta analyses of the wage risk VSL literature. 31 As indicated in the regulatory impact analysis for the Clean Air Interstate Rule ( CAIR), these studies support a 95 percent confidence interval ranging from $ 1 million to $ 10 million, with a mean value of $ 5.5 million ( all values expressed in 1999 dollars and assume 1990 income levels). 32 To express mortality benefits in 2002 dollars, consistent with the cost estimates presented in Chapter 5, we adjust these values to year 2002 dollars using the GDP deflator. In addition, because these values reflect per capita income in 1990, we adjust them upward to reflect income in 2005. These adjustments yield a central VSL value of $ 6.2 million ( in year 2002 dollars) and low and high values of $ 1.1 million and $ 11.4 million respectively. 33 To value the mortality risk reductions, we multiply the expected number of avoided mortality cases by these central, low, and high VSL values.

We apply a similar approach to estimating the value of avoided morbidity impacts. For each of these health effects, we multiply the expected number of avoided cases by the corresponding WTP or COI value. For six of the nine morbidity effects included in the risk assessment, we use WTP estimates derived from various sources. For acute bronchitis and hospital admissions related to cardiovascular disease or respiratory illness, however, we use COI estimates. For hospital admissions, these estimates reflect hospital charges, the costs of associated physician care, and the opportunity cost of time spent in the hospital. 34 Because COI estimates do not reflect the pain and suffering of the afflicted individuals, these estimates may understate benefits associated with avoided IEc Draft: May 2005 6 15 hospital admissions. Exhibit 6 2 summarizes the values associated with each health endpoint.

Exhibit 6 2 AVOIDED COST OF CASES ASSOCIATED WITH PM Illness Estimated Cost Per Incidence ( 2002 $)

Premature mortality1 Low: $ 1.1 million Central: $ 6.2 million High: $ 11.4 million Respiratory illness hospital admissions2 $ 9,011 Upper respiratory symptoms3 $ 27 Lower respiratory symptoms3 $ 18 Chronic bronchitis4 $ 393,530 Acute bronchitis3 $ 419 Cardiovascular disease hospital admissions2 $ 15,018 Work loss days ( cost per day) 5 $ 137 Minor restricted activity days ( cost per day) 4 $ 56 Sources: 1 Mrozek, J. R., and L. O. Taylor. 2002. " What Determines the Value of Life? A Meta Analysis." Journal of Policy Analysis and Management 21( 2): 253 270 and Viscusi, V. K., and J. E. Aldy. 2003. " The Value of a Statistical Life: A Critical Review of Market Estimates Throughout the World." Journal of Risk and Uncertainty 27( 1): 5 76 as cited in U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005. Estimate adjusted to reflect 2005 income. 2 U. S. Environmental Protection Agency, The Benefits and Costs of the Clean Air Act, 1970 to 1990, October 1997, I11 I12; Abt Associates, Incorporated, The Medical Costs of Five Illnesses Related to Exposure to Pollutants, Prepared for U. S. EPA, Office of Pollution Prevention and Toxics, Washington, DC, 1992, as cited in U. S. EPA, Assessment of the Potential Costs, Benefits, and Other Impacts of the Hazardous Waste Combustion MACT Standards: Final Rule, Office of Solid Waste, July 1999; A. Elixhauser, R. M. Andrews, and S. Fox, Agency for Health Care Policy and Research ( AHCPR), Center for General Health Services Intramural Research, U. S. Department of Health and Human Services, Clinical Classifications for Health Policy Research: Discharge Statistics by Principal Diagnosis and Procedure, 1993, as cited in U. S. EPA, Assessment of the Potential Costs, Benefits, and Other Impacts of the Hazardous Waste Combustion MACT Standards: Final Rule, Office of Solid Waste, July 1999.. 3 Neumann, J. E., M. T. Dickie, and R. E. Unsworth. 1994. Industrial Economics, Incorporated. Memorandum to Jim DeMocker, U. S. EPA, Office of Air and Radiation. Linkage Between Health Effects Estimation and Morbidity Valuation in the Section 812 Analysis  Draft Valuation Document. March 31, as cited in U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005. Estimate adjusted to reflect 2005 income. 4 Derived from Viscusi, W. K., W. A. Magat, and J. Huber. 1991. " Pricing Environmental Health Risks: Survey Assessments of Risk Risk and Risk Dollar Trade Offs for Chronic Bronchitis." Journal of Environmental Economics and Management 21: 32 51 as cited in U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005. Estimate adjusted to reflect 2005 income. 5 Estimated from results of U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005, which estimated $ 180 million ( 1999$) in benefits associated with 1.4 million avoided work loss days in 2010. Note: Cardiovascular disease is assumed to be Ischemic heart disease. IEc Draft: May 2005 35 U. S. Environmental Protection Agency Science Advisory Board, EPA SAB COUNCIL ADV 04 004, Review of The Revised Analytical Plan for EPA's Second Prospective Analysis Benefits and Costs of The Clean Air Act 1990 2020, May 2004.

36 Ibid.

6 16 Many of the values in Exhibit 6 2 are derived from estimates presented in the 1999 Assessment or in EPA's regulatory impact analysis of the Clean Air Interstate Rule. We also considered several alternative values available through the Environmental Evaluation Research Inventory ( EVRI), an online database designed by Environment Canada in conjunction with EPA to assist policy analysts in benefits transfer applications. EVRI summarizes the findings of numerous studies examining the benefits of specific improvements in environmental quality. The summaries of several studies in EVRI provide alternative estimates for some of the endpoints presented in Exhibit 6 2. None of these alternative values, however, were more appropriate than the values listed in Exhibit 6 2.

Valuing Lagged Benefits Most of the mortality benefits associated with the HWC MACT replacement standards may not be realized immediately because of a time lag between changes in PM and dioxin exposure and the resulting change in the mortality rate. This lag is important in our assessment of the value of the health benefits associated with the replacement standards because society generally values benefits realized at present more than benefits realized in the future. To account for society's preference for current benefits over future benefits, we discount benefits realized in the future, expressing all benefits estimates in consistent, present value terms. The selection of a discount rate for estimating the present value of future benefits, however, is a complex issue, as the economic literature points to two different approaches for measuring the social discount rate. Under the " demand side" approach, the social discount rate reflects " the sum of a pure social rate of time preference and an adjustment term reflecting future changes in the marginal utility of consumption ( future goods may be worth less at the margin as people get richer)." 35 Most estimates of the social discount rate under the demand side approach fall within a range of 1 to 4 percent. In contrast, the " cost side" approach to estimating the discount rate defines the social discount rate in terms of the shadow price of capital, which reflects the " real world tradeoff between present and future consumption implied by the marginal productivity of capital." 36 Estimated values of the shadow price of capital vary but generally fall within the range of 4 to 10 percent. To reflect benefits under both of these approaches, we present two estimates of discounted benefits, one based on a 3 percent discount rate and another based on a 7 percent discount rate.

Another important issue is estimating the value of lagged mortality benefits is identifying the duration of the lag associated with each pollutant. For PM induced mortality, this lag is highly uncertain. For PM 2.5 the Health Effects Subcommittee of EPA's Science Advisory Board has recommended that until additional research has been completed, EPA should assume a segmented lag structure according to which 30 percent of mortality reductions occur during the first year after the reduction in PM 2.5 emissions, 50 percent occur evenly from the second through fifth years, and 20 percent occur evenly from the sixth through twentieth years after the initial reduction in PM 2.5 IEc Draft: May 2005 37 U. S. EPA, Regulatory Impact Analysis for the Final Interstate Air Quality Rule, March 2005.

38 Jim Neumann and Bob Unsworth, Addenda to Mortality Valuation Methodology, internal memorandum submitted to Jim DeMocker, September 28, 1993.

39 Because the dioxin related benefits expected under the replacement standards are relatively small, the benefits associated with each end of this range round to the same value.

6 17 emissions. 37 The SAB's recommendation applies only to PM 2.5 ( i. e., particles with a diameter of less than 2.5 microns), but for the purposes of this analysis, we apply the same lag structure to particles larger than 10 microns in diameter.

The lag associated with cancer deaths resulting from dioxin exposure is also highly uncertain. Based on data presented in the epidemiological literature, we assume a 21 to 34 year lag between reduced dioxin emissions and avoided cancer related mortality. 38 We estimate dioxin related benefit values consistent each end of this range. 39 Human Health Benefit Results This section presents the results of our analysis of the human health benefits associated with HWC MACT replacement standards. We present results for the Option A Floor, the Option C Floor, and the Option D Floor, as well as for the Agency Preferred Approach, which represents a beyondthe floor extension of the Option A Floor. We quantify benefits resulting from reduced PM and dioxin emissions, but inadequate information was available to measure benefits associated with other pollutants. For lead and mercury, however, we discuss how the benefits of the HWC MACT replacement standards are likely to differ from the benefits estimates presented in the 1999 Assessment. We also discuss the potential benefits associated with reduced emissions of hydrogen chloride and chlorine gas.

In general, the 1999 standards resulted in greater emissions reductions than those expected under the HWC MACT replacement standards ( Exhibit 6 3). This finding is not surprising because most of the emissions reductions that would have been achieved under the 1999 Standards are achieved under the 2002 Interim Standards, which define the baseline of our analysis. Notably, PM emissions reductions under the Option D Floor are greater than the PM emissions reductions associated with the 1999 standards. Among the HWC MACT replacement options, the Option D Floor would yield the most significant emissions reductions and human health benefits. The Agency Preferred Approach would generate more significant emissions reductions and human health benefits than the Option A Floor and the Option C Floor. IEc Draft: May 2005 6 18 Exhibit 6 3 ANNUAL EMISSIONS REDUCTIONS FOR THE FINAL HWC MACT REPLACEMENT STANDARDS Standard Particulate Matter ( tons/ yr) Mercury ( tons/ yr) SVM/ LVM ( tons/ yr) Dioxins/ Furans ( grams/ yr) Chlorine ( tons/ yr) Agency Preferred Approach 2,138 0.2 12.3 0.4 107 Option A Floor 1,669 0.2 11.5 0.3 107 Option C Floor 1,669 0.2 12.0 0.3 107 Option D Floor 3,005 0.6 18.6 0.3 127 1999 Standards 2,449 3.9 97.1 28.7 5,132 Source: EERGC, Inc., April 29, 2005.

A summary of the quantified benefits for the Agency Preferred Approach is presented in Exhibit 6 4. Exhibits 6 5 and 6 6 summarize benefits under the Option A Floor, the Option C Floor, and the Option D Floor. We describe the results in more detail below. IEc Draft: May 2005 6 19 Exhibit 6 4 HUMAN HEALTH BENEFITS SUMMARY: BASELINE TO AGENCY PREFERRED APPROACH Type of Benefit Avoided Cases per Year Annual Nondiscounted Value ( millions of 2002 dollars) Annual Discounted Value  3 Percent Discount Rate ( millions of 2002 dollars) Annual Discounted Value  7 Percent Discount Rate ( millions of 2002 dollars) PM related Health Benefits Premature mortalitya 0.46 $ 2.87 $ 2.52 $ 2.19 ($ 0.52$ 5.21) ($ 0.46$ 4.58) ($ 0.40$ 3.97)

Respiratory Illness Hospital Admissions 1.21 $ 0.01 $ 0.01 $ 0.01 Cardiovascular Disease Hospital Admissions 0.53 $ 0.01 $ 0.01 $ 0.01 Chronic Bronchitis 7.70 $ 3.03 $ 3.03 $ 3.03 Acute Bronchitis 5.86 $ 0.00 $ 0.00 $ 0.00 Lower Respiratory Symptoms 51.95 $ 0.00 $ 0.00 $ 0.00 Upper Respiratory Symptoms 6.02 $ 0.00 $ 0.00 $ 0.00 Minor Restricted Activity Days 5,142 $ 0.29 $ 0.29 $ 0.29 Work Loss Days 617 $ 0.08 $ 0.08 $ 0.08 Total PM Health Benefits $ 6.29 $ 5.95 $ 5.61 Dioxin related Health Benefits Total dioxin related cancer deathsb 0.005 $ 0.03 $ 0.01$ 0.02c $ 0.00$ 0.01c ($ 0.01$ 0.06) a ($ 0.00$ 0.03) d ($ 0.00$ 0.01) d TOTAL HUMAN HEALTH BENEFITS $ 6.32 $ 5.96 $ 5.62 Notes: a. Avoided premature mortality benefit estimates reflect a VSL range of $ 1.1 million to $ 11.4 million, with a central VSL estimate of $ 6.2 million. These values are derived from willingness to pay based VSL estimates presented in U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005. VSL estimates reflect income in 2005 were adjusted to 2002 dollars using the GDP deflator. b. The primary estimate of dioxin benefits presented here reflects EPA's current guidance on the cancer risk ( 1.5 x 105 [ mg/ kg/ day] 1) associated with dioxin/ furans. The Agency has been conducting a reassessment of the human health risks associated with dioxin and dioxin like compounds. This reassessment is currently under review at the National Academy of Sciences ( NAS). Evidence compiled from this draft reassessment indicates that the carcinogenic effects of dioxin/ furans may be six times greater than estimated in the 1985 analysis with an upper bound cancer risk slope factor of 1 x 106 [ mg/ kg/ day] 1 for some individuals. c. This range of monetized benefits reflects a 21 34 year between dioxin exposure and death ( Jim Neumann and Bob Unsworth, Addenda to Mortality Valuation Methodology, internal memorandum submitted to Jim DeMocker, U. S. EPA Office of Air and Radiation, September 28, 1993) and a central VSL value of $ 6.2 million derived from U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005. This value reflects income in 2005 and was converted to 2002 dollars using the GDP deflator. d. This range reflects the 21 34 year period between dioxin exposure and death ( Jim Neumann and Bob Unsworth, Addenda to Mortality Valuation Methodology, internal memorandum submitted to Jim DeMocker, September 28, 1993) and VSL values ranging from $ 1.1 million to $ 11.4 million ( U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005). VSL estimates reflect income in 2005 and are adjusted to 2002 dollars using the GDP deflator. IEc Draft: May 2005 6 20 Exhibit 6 5 HUMAN HEALTH BENEFITS SUMMARY: REDUCED INCIDENCE OF ADVERSE HEALTH EFFECTS Type of Benefit Agency Preferred Approach Option A Floor Option C Floora Option D Floor PM related Health Benefits Premature mortality 0.46 0.455 0.45 0.75 Respiratory Illness Hospital Admissions 1.21 1.20 1.20 1.97 Cardiovascular Disease Hospital Admissions 0.53 0.52 0.52 0.87 Chronic Bronchitis 7.70 7.65 7.65 12.54 Acute Bronchitis 5.86 5.81 5.81 9.60 Lower Respiratory Symptoms 51.95 51.53 51.53 85.15 Upper Respiratory Symptoms 6.02 5.98 5.98 9.88 Minor Restricted Activity Days 5,142 5,103 5,103 8,391 Work Loss Days 617 613 613 1,007 Dioxin related Health Benefits Dioxin related cancer deaths 0.005 0.004 0.004 0.004 Notes: a. In developing the HWC MACT replacement standards, EPA also considered an Option B Floor. IEc Draft: May 2005 6 21 Exhibit 6 6 HUMAN HEALTH BENEFITS SUMMARY: BASELINE TO AGENCY PREFERRED APPROACH ( millions of 2002 dollars)

Option Option A Floor Option C Floor Option D Floor Type of Benefit Annual Nondiscounted Value Annual Discounted Value  3 Percent Discount Rate Annual Discounted Value  7 Percent Discount Rate Annual Nondiscounted Value Annual Discounted Value  3 Percent Discount Rate Annual Discounted Value  7 Percent Discount Rate Annual Nondiscounted Value Annual Discounted Value  3 Percent Discount Rate Annual Discounted Value  7 Percent Discount Rate PM related Health Benefits Premature mortalitya $ 2.84 $ 2.50 $ 2.17 $ 2.84 $ 2.50 $ 2.17 $ 4.66 $ 4.10 $ 3.55 ($ 0.52$ 5.17) ($ 0.45$ 4.55) ($ 0.39$ 3.94) ($ 0.52$ 5.17) ($ 0.45$ 4.55) ($ 0.39$ 3.94) ($ 0.85$ 8.47) ($ 0.74$ 7.45) ($ 0.65$ 6.46)

Respiratory Illness Hospital Admissions $ 0.01 $ 0.01 $ 0.01 $ 0.01 $ 0.01 $ 0.01 $ 0.02 $ 0.02 $ 0.02 Cardiovascular Disease Hospital Admissions $ 0.01 $ 0.01 $ 0.01 $ 0.01 $ 0.01 $ 0.01 $ 0.01 $ 0.01 $ 0.01 Chronic Bronchitis $ 3.01 $ 3.01 $ 3.01 $ 3.01 $ 3.01 $ 3.01 $ 4.93 $ 4.93 $ 4.93 Acute Bronchitis $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 Lower Respiratory Symptoms $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 Upper Respiratory Symptoms $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 Minor Restricted Activity Days $ 0.29 $ 0.29 $ 0.29 $ 0.29 $ 0.29 $ 0.29 $ 0.47 $ 0.47 $ 0.47 Work Loss Days $ 0.08 $ 0.08 $ 0.08 $ 0.08 $ 0.08 $ 0.08 $ 0.14 $ 0.14 $ 0.14 Total PM Health Benefitsa $ 6.24 $ 5.90 $ 5.57 $ 6.24 $ 5.90 $ 5.57 $ 10.23 $ 9.67 $ 9.13 ($ 3.92$ 8.57) ($ 3.86$ 7.95) ($ 3.79$ 7.34) ($ 3.92$ 8.57) ($ 3.86$ 7.95) ($ 3.79$ 7.34) ($ 6.42$ 14.04) ($ 6.32$ 13.03) ($ 6.22$ 12.03) IEc Draft: May 2005 Exhibit 6 6 HUMAN HEALTH BENEFITS SUMMARY: BASELINE TO AGENCY PREFERRED APPROACH ( millions of 2002 dollars)

Option Option A Floor Option C Floor Option D Floor Type of Benefit Annual Nondiscounted Value Annual Discounted Value  3 Percent Discount Rate Annual Discounted Value  7 Percent Discount Rate Annual Nondiscounted Value Annual Discounted Value  3 Percent Discount Rate Annual Discounted Value  7 Percent Discount Rate Annual Nondiscounted Value Annual Discounted Value  3 Percent Discount Rate Annual Discounted Value  7 Percent Discount Rate 6 22 Dioxin related Health Benefits Dioxin related cancer deathsb $ 0.03 $ 0.01 $ 0.00$ 0.01c $ 0.03 $ 0.01 $ 0.00$ 0.01c $ 0.03 $ 0.01 $ 0.00$ 0.01c ($ 0.00$ 0.05) d ($ 0.00$ 0.03) d ($ 0.00$ 0.01) d ($ 0.00$ 0.05) d ($ 0.00$ 0.03) d ($ 0.00$ 0.01) d ($ 0.00$ 0.05) d ($ 0.00$ 0.03) d ($ 0.00$ 0.01) d TOTAL HUMAN HEALTH BENEFITS  MONETIZED $ 6.27 $ 5.92 $ 5.57 $ 6.27 $ 5.92 $ 5.57 $ 10.26 $ 9.69 $ 9.14 Notes:

e. Avoided premature mortality benefit estimates reflect a VSL range of $ 1.1 million to $ 11.4 million, with a central VSL estimate of $ 6.2 million. These values are derived from willingness to pay based VSL estimates presented in U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005. VSL estimates reflect income in 2005 and were adjusted to 2002 dollars using the GDP deflator.

f. The primary estimate of dioxin benefits presented here reflects EPA's current guidance on the cancer risk ( 1.5 x 105 [ mg/ kg/ day] 1) associated with dioxin/ furans. The Agency has been conducting a reassessment of the human health risks associated with dioxin and dioxin like compounds. This reassessment will is currently under review at the National Academy of Sciences ( NAS). Evidence compiled from this draft reassessment indicates that the carcinogenic effects of dioxin/ furans may be as much as six times as great as believed in 1985, reflecting an upper bound cancer risk slope factor of 1 x 106 [ mg/ kg/ day] 1 for some individuals.

g. This range of monetized benefits reflects a 21 34 year between dioxin exposure and death ( Jim Neumann and Bob Unsworth, Addenda to Mortality Valuation Methodology, internal memorandum submitted to Jim DeMocker, U. S. EPA Office of Air and Radiation, September 28, 1993) and a central VSL value of $ 6.2 million derived from U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005. This VSL value reflects income in 2005 and was converted to 2002 dollars with the GDP deflator.

h. Range in parentheses reflects the 21 34 year period between dioxin exposure and death ( Jim Neumann and Bob Unsworth, Addenda to Mortality Valuation Methodology, internal memorandum submitted to Jim DeMocker, September 28, 1993) and VSL values ranging from $ 1.1 million to $ 11.4 million ( U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005). VSL estimates reflect income levels in 2005 and were adjusted to 2002 dollars using the GDP deflator. IEc Draft: May 2005 40 U. S. EPA, 1985. Health Assessment Document for Polychlorinated Dibenzo p Dioxins. EPA/ 600/ 8 84/ 014F. Final Report. Office of Health and Environmental Assessment. Washington, DC. September, 1985.

41 We assume that this lag period is approximately 21 to 34 years, consistent with estimates presented in Jim Neumann and Bob Unsworth, Addenda to Mortality Valuation Methodology, internal memorandum submitted to Jim DeMocker, U. S. EPA Office of Air and Radiation, September 28, 1993.

42 U. S. EPA, Exposure and Human Health Reassessment of 2,3,7,8 Tetrachlorodibenzo p Dioxin ( TCDD) and Related Compounds: NAS Review Draft, December 2003. Note: Toxicity risk factors presented in this document should not be considered EPA's official estimate of dioxin toxicity, but rather reflect EPA's ongoing effort to reevaluate dioxin toxicity.

6 23 Benefits from Cancer Risk Reductions Dioxin  Approximately 0.005 cancer related deaths per year are expected to be avoided under the Agency Preferred Approach. The three floor options included in this analysis would reduce the incidence of cancer related mortality by approximately 0.004 cases per year. These estimates reflect a cancer risk slope factor of 1.56 x 105 [ mg/ kg/ day] 1. This cancer slope factor is derived from the Agency's 1985 health assessment document for polychlorinated dibenzo p dioxins and represents an upper bound 95th percentile confidence limit of the excess cancer risk from lifetime exposure. 40 The total value of the avoided cancer deaths under the Agency Preferred Approach ranges from less than $ 10,000 per year to approximately $ 60,000 per year, depending on assumptions about the lag between dioxin exposure and the time of avoided mortality. 41 For the past several years EPA has been conducting a reassessment of the human health risks associated with dioxin and dioxin like compounds. In October of 2004, the Agency submitted its reassessment of dioxin risk to the National Academy of Sciences ( NAS) for review. 42 Evidence compiled from this draft reassessment indicates that the cancer risk associated with dioxin/ furans may be six times greater than the risk estimate EPA developed in 1985, with an upper bound cancer risk slope factor of 1 x 106 [ mg/ kg/ day] 1 for some individuals. Agency scientists' more likely ( central tendency) estimates suggest slope factors and risk factors approximately 2 3 times higher than the 1985 estimate ( i. e., between 3 x 105 [ mg/ kg/ day] 1 and 5 x 105 [ mg/ kg/ day] 1), based on the available epidemiological and animal cancer data. Risks could be as low as zero for some individuals. The alternative upper bound cancer risk slope factor suggests that 0.03 premature cancer deaths will be avoided under the Agency Preferred Approach because of reduced dioxin emissions. This estimate does not reflect Agency policy, as EPA is currently awaiting feedback on the alternative slope factor from the National Academy of Sciences. The dioxin standards for the Final Rule are based on the 1.56 x 105 [ mg/ kg/ day] 1 slope factor developed in 1985, not the alternative slope factor currently under consideration. IEc Draft: May 2005 43 Other pollutants were found to pose negligible individual risks and are not included in the results.

44 Grandjean, P., K. Murata, E. Budtz Jorgensen, and P. Weihe. 2004. " Autonomic Activity in Methylmercury Neurotoxicity: 14 Year Follow Up of a Faroese Birth Cohort." Journal of Pediatrics. 144: 169 76; Kjellstrom, T., P.

6 24 Benefits from Non Cancer Risk Reductions Most of the human health benefits resulting from the HWC MACT replacement standards are associated with reduced emissions of particulate matter. Additional non cancer benefits are also likely to result from reduced emissions of lead, mercury, and chlorine, although such benefits are not quantified in this analysis. 43 Annual non discounted, non cancer health benefits are valued at approximately $ 6.24 million under the Option A Floor and Option C Floor, $ 10.23 million under the Option D Floor, and $ 6.29 under the Agency Preferred Approach.

Particulate Matter. The HWC MACT replacement standards are expected to reduce premature mortality by less than one case per year for all four regulatory options included in this analysis. In addition, the Agency Preferred Approach is expected to reduce the incidence of chronic bronchitis by 7.7 cases per year and hospital admissions associated with cardiovascular disease or respiratory illness by 1.74 cases per year. These and other human health benefits related to reduced PM exposure are valued at $ 5.61 million to $ 6.29 million per year under the Agency Preferred Approach, depending on discounting assumptions. The mortality benefits reflected in these estimates are uncertain, as the value of a statistical life may be as low as $ 1.1 million or as high as $ 11.4 million. Under these alternative VSL values, benefits associated with avoided mortality range from $ 0.40 million ($ 1.1 million VSL, 7 percent discount rate) to $ 5.21 million ($ 11.4 million VSL, benefits not discounted).

Mercury. The HWC MACT replacement standards are expected to reduce mercury emissions by approximately 0.25 tons per year, approximately 93 percent less than the four ton reduction expected under the 1999 Standards. We do not attempt to quantify the mercury related benefits associated with the replacement standards. However, because the reduction in mercury emissions resulting from the replacement standards represents a fraction of the reduction expected under the 1999 Standards, the mercury related benefits of the replacement standards are likely to be less than the corresponding benefits under the 1999 Standards.

To characterize the benefits associated with reduced mercury emissions, the 1999 Assessment measured changes in hazard quotients for populations living near hazardous waste combustion facilities. For any given population, the hazard quotient is the ratio of the actual level of exposure to a safe level of exposure. A hazard quotient greater than one implies that a population is potentially at risk. The exposure quotient analysis in the 1999 Assessment found that the measurable benefits of reduced mercury emissions under the 1999 Standards were likely to be small because baseline exposures were relatively low. In addition, many of the studies examining the adverse health effects of mercury are inconclusive, although three large scale epidemiological studies indicate that children of women exposed to unsafe levels of mercury during their pregnancies may experience hindered neuro development. 44 EPA's recent regulatory impact analysis of the Clean Air Mercury Rule IEc Draft: May 2005 Kennedy, S. Wallis, A. Stewart, L. Friberg, B. Lind, P. Witherspoon, and C. Mantell. 1989. Physical and mental development of children with prenatal exposure to mercury from fish. Stage 2: Interviews and psychological tests at age 6. National Swedish Environmental Protection Board Report No. 3642; Crump, K. S., T. Kjellstrom, A. M. Shipp, A. Silvers, and A. Stewart. 1998. " Influence of prenatal mercury exposure upon scholastic and psychological test performance: benchmark analysis of a New Zealand cohort." Risk Analysis. 18( 6): 701 713; Davidson, P. W., G. J. Myers, C. Cox, C. Axtell, C. Shamlaye, J. Sloane Reeves, E. Cernichiari, L. Needham, A. Choi, Y. Wang, M. Berlin, and T. W. Clarkson. 1998. " Effects of prenatal and postnatal methylmercury exposure from fish consumption on neurodevelopment: outcomes at 66 months of age in the Seychelles Child Development Study." Journal of the American Medical Association. 280( 8): 701 707; and Myers, G. J., P. W. Davidson, C. Cox, C. F. Shamlaye, D. Palumbo, E. Cernichiari, J. Sloane Reeves, G. E. Wilding, J. Kost, L. S. Huang, and T. W. Clarkson. 2003. " Prenatal methylmercury exposure from ocean fish consumption in the Seychelles child development study." Lancet. 361( 9370): 1686 92.

45 U. S. EPA. Regulatory Impact Analysis of the Clean Air Mercury Rule: Final Report. March 2005.

46 The primary form of lead exposure to children is via ingestion of contaminated soil.

6 25 summarizes several other adverse health effects that may be linked to mercury and reviews the epidemiological literature examining the link between these effects and exposure to mercury. 45 Lead. The HWC MACT replacement standards will reduce lead emissions by approximately 2.5 tons per year under the Agency Preferred Approach. By comparison, the 1999 Standards would have reduced lead emissions by 89 tons per year, causing cumulative lead exposures to decline to less than 10 µ g/ dL for seven children younger than the age of six. 46 Given the relatively modest emissions reductions associated with the replacement standards, the Final Rule is likely to reduce cumulative lead exposure from above to below 10 µ g/ dL for fewer than two to seven children per year. The HWC MACT replacement standards will also result in reduced lead levels for children in subpopulations with especially high levels of exposure. For instance, children of subsistence fishermen, commercial beef farmers, and commercial dairy farmers who face the greatest levels of cumulative lead exposure are likely to experience the most significant reductions in overall exposure as a result of the replacement standards. The small number of cases identified in the 1999 Assessment suggests that these benefits will be small.

Human Health Benefits Summary As indicated in Exhibit 6 5, the annual human health benefits associated with the Agency Preferred Approach for the HWC MACT replacement standards include less than one avoided premature mortality, 7.7 avoided cases of chronic bronchitis, 1.7 fewer hospital admissions, nearly 58 avoided cases of lower or upper respiratory symptoms, and approximately 5,760 avoided work loss or minor restricted activity days. Nearly all of these estimated benefits result from reduced PM emissions, although a small fraction are associated with reduced dioxin emissions. The estimated non discounted value for these benefits is approximately $ 6.32 million per year. The Agency Preferred Approach is also likely to generate additional health benefits that are not quantified, including benefits associated with reduced emissions of chlorine, mercury, semi volatile metals, and IEc Draft: May 2005 6 26 low volatile metals. This analysis quantifies only the human health benefits associated with reduced PM and dioxin emissions.

Human health benefits under the Option A Floor and Option C Floor are similar to those achieved under the Agency Preferred Approach. Both options reduce premature mortality by less than one case per year, result in 1.7 fewer hospital admissions on an annual basis, and reduce the incidence of new chronic bronchitis cases by nearly 7.7 cases per year. The number of avoided work loss and minor restricted activity days under these two options   5,716 days   is slightly lower than under the Agency Preferred Approach. In monetary terms, the human health benefits of the Option A and C Floors, $ 6.27 million in non discounted benefits, are slightly less than the benefits associated with the Agency Preferred Approach.

Human health benefits associated with the Option D Floor are more significant than the benefits under the other three options. Benefits achieved under this option include 0.75 avoided premature mortality cases per year ( compared to 0.46 cases under the Agency Preferred Approach), approximately 2.8 fewer hospital admissions, more than 12.5 avoided cases of chronic bronchitis, approximately 95 avoided cases of lower or upper respiratory symptoms, and approximately 9,400 avoided work loss or minor restricted activity days. The total nondiscounted value of these human health benefits is approximately $ 10.26 million, which is approximately 62 percent greater than the benefits associated with the Agency Preferred Approach. This difference largely reflects the more significant reduction in PM emissions achieved under the Option D Floor relative to the Agency Preferred Approach. As indicated in Exhibit 6 3, PM emissions would decline by more than 3,000 tons per year under the Option D Floor, while the Agency Preferred Approach would reduce PM emissions by 2,140 tons per year.

Exhibit 6 7 summarizes the quanitifiable human health benefits across combustion source categories for the Agency Preferred Approach and the three Floor options. Overall, most of the human health benefits associated with the replacement standards result from reduced PM emissions from liquid boilers. This concentration of benefits among liquid boilers reflects the fact that nearly 40 percent of the combustion systems regulated by the HWC MACT replacement standards are liquid boilers. The second most numerous source category, on site incinerators, represent approximately 35 percent of the HWC MACT universe. Unlike on site incinerators, however, liquid boilers are not regulated under the 2002 Interim Standards. Implementing new emissions controls at liquid boilers is therefore more likely to yield significant health benefits than additional control measures at on site incinerators. IEc DRAFT: May 2005 6 27 Exhibit 6 7 SUMMARY OF BENEFITS BY SOURCE CATEGORY Type of Benefit Agency Preferred Approach Option A Floor Option C Floor Option D Floor Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions)

Cement Kilns/ Human Health Benefits Dioxin related mortalitya 0.000 $ 0.00 0.000 $ 0.00 0.000 $ 0.00 0.000 $ 0.00 PM related mortalitya 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Respiratory Illness Hospital Admissions 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.01 $ 0.00 Cardiovascular Disease Hospital Adm. 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.01 $ 0.00 Chronic Bronchitis 0.01 $ 0.00 0.01 $ 0.00 0.01 $ 0.00 0.07 $ 0.03 Acute Bronchitis 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.06 $ 0.00 Lower Respiratory Symptoms 0.04 $ 0.00 0.04 $ 0.00 0.04 $ 0.00 0.53 $ 0.00 Upper Respiratory Symptoms 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.06 $ 0.00 Minor Restricted Activity Days 2.25 $ 0.00 2.25 $ 0.00 2.25 $ 0.00 28.08 $ 0.00 Work Loss Days 0.27 $ 0.00 0.27 $ 0.00 0.27 $ 0.00 3.37 $ 0.00 Subtotal  $ 0.00  $ 0.00  $ 0.00  $ 0.03 LWAK/ Human Health Benefits Dioxin related mortalitya 0.000 $ 0.00 0.000 $ 0.00 0.000 $ 0.00 0.000 $ 0.00 PM related mortalitya 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Respiratory Illness Hospital Admissions 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Cardiovascular Disease Hospital Adm. 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Chronic Bronchitis 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Acute Bronchitis 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Lower Respiratory Symptoms 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Upper Respiratory Symptoms 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Minor Restricted Activity Days 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Work Loss Days 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Subtotal  $ 0.00  $ 0.00  $ 0.00  $ 0.00 IEc DRAFT: May 2005 Exhibit 6 7 SUMMARY OF BENEFITS BY SOURCE CATEGORY Type of Benefit Agency Preferred Approach Option A Floor Option C Floor Option D Floor Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions)

6 28 Incinerator/ Human Health Benefits Dioxin related mortalitya 0.003 $ 0.02 0.003 $ 0.02 0.003 $ 0.02 0.003 $ 0.02 PM related mortalitya 0.01 $ 0.04 0.01 $ 0.04 0.01 $ 0.04 0.08 $ 0.48 Respiratory Illness Hospital Admissions 0.02 $ 0.00 0.02 $ 0.00 0.02 $ 0.00 0.19 $ 0.00 Cardiovascular Disease Hospital Adm. 0.01 $ 0.00 0.01 $ 0.00 0.01 $ 0.00 0.09 $ 0.00 Chronic Bronchitis 0.10 $ 0.04 0.10 $ 0.04 0.10 $ 0.04 1.23 $ 0.49 Acute Bronchitis 0.08 $ 0.00 0.08 $ 0.00 0.08 $ 0.00 1.01 $ 0.00 Lower Respiratory Symptoms 0.74 $ 0.00 0.74 $ 0.00 0.74 $ 0.00 9.00 $ 0.00 Upper Respiratory Symptoms 0.09 $ 0.00 0.09 $ 0.00 0.09 $ 0.00 1.04 $ 0.00 Minor Restricted Activity Days 71.19 $ 0.00 71.19 $ 0.00 71.19 $ 0.00 867.32 $ 0.05 Work Loss Days 8.55 $ 0.00 8.55 $ 0.00 8.55 $ 0.00 104.11 $ 0.01 Subtotal  $ 0.10  $ 0.10  $ 0.10  $ 1.05 Coal Boiler/ Human Health Benefits Dioxin related mortalitya 0.000 $ 0.00 0.000 $ 0.00 0.000 $ 0.00 0.000 $ 0.00 PM related mortalitya 0.00 $ 0.03 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Respiratory Illness Hospital Admissions 0.01 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Cardiovascular Disease Hospital Adm. 0.01 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Chronic Bronchitis 0.06 $ 0.02 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Acute Bronchitis 0.05 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Lower Respiratory Symptoms 0.46 $ 0.00 0.03 $ 0.00 0.03 $ 0.00 0.03 $ 0.00 Upper Respiratory Symptoms 0.05 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Minor Restricted Activity Days 41.62 $ 0.00 3.17 $ 0.00 3.17 $ 0.00 3.17 $ 0.00 Work Loss Days 5.00 $ 0.00 0.38 $ 0.00 0.38 $ 0.00 0.38 $ 0.00 Subtotal  $ 0.05  $ 0.00  $ 0.00  $ 0.00 IEc DRAFT: May 2005 Exhibit 6 7 SUMMARY OF BENEFITS BY SOURCE CATEGORY Type of Benefit Agency Preferred Approach Option A Floor Option C Floor Option D Floor Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions)

6 29 HCl Production Furnace/ Human Health Benefits Dioxin related mortalitya 0.000 $ 0.00 0.000 $ 0.00 0.000 $ 0.00 0.000 $ 0.00 PM related mortalitya 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Respiratory Illness Hospital Admissions 0.00 $ 0.00 0.00 $ 0.00 0.01 $ 0.00 0.00 $ 0.00 Cardiovascular Disease Hospital Adm. 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Chronic Bronchitis 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Acute Bronchitis 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Lower Respiratory Symptoms 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Upper Respiratory Symptoms 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Minor Restricted Activity Days 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Work Loss Days 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 0.00 $ 0.00 Subtotal  $ 0.00  $ 0.00  $ 0.00  $ 0.00 Liquid Boiler/ Human Health Benefits Dioxin related mortalitya 0.002 $ 0.02 0.002 $ 0.01 0.002 $ 0.01 0.002 $ 0.01 PM related mortalitya 0.45 $ 2.80 0.45 $ 2.80 0.45 $ 2.80 0.67 $ 4.18 Respiratory Illness Hospital Admissions 1.19 $ 0.01 1.19 $ 0.01 1.19 $ 0.01 1.77 $ 0.02 Cardiovascular Disease Hospital Adm. 0.52 $ 0.01 0.52 $ 0.01 0.52 $ 0.01 0.77 $ 0.01 Chronic Bronchitis 7.54 $ 2.97 7.54 $ 2.97 7.54 $ 2.97 11.23 $ 4.42 Acute Bronchitis 5.72 $ 0.00 5.72 $ 0.00 5.72 $ 0.00 8.52 $ 0.00 Lower Respiratory Symptoms 50.71 $ 0.00 50.71 $ 0.00 50.71 $ 0.00 75.59 $ 0.00 Upper Respiratory Symptoms 5.88 $ 0.00 5.88 $ 0.00 5.88 $ 0.00 8.77 $ 0.00 Minor Restricted Activity Days 5,026.73 $ 0.28 5,026.73 $ 0.28 5,026.73 $ 0.28 7,492.79 $ 0.42 Work Loss Days 603.40 $ 0.08 603.40 $ 0.08 603.40 $ 0.08 899.43 $ 0.12 Subtotal  $ 6.17  $ 6.16  $ 6.16  $ 9.18 TOTAL HEAlTH BENEFITS  $ 6.32  $ 6.27  $ 6.27  $ 10.26 IEc DRAFT: May 2005 Exhibit 6 7 SUMMARY OF BENEFITS BY SOURCE CATEGORY Type of Benefit Agency Preferred Approach Option A Floor Option C Floor Option D Floor Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions) Annual Reduction in Number of Cases Annual Nondiscounted Value ( 2002$

millions)

6 30 Notes:

a. Avoided premature mortality benefit estimates reflect a central VSL value of $ 6.2 million. This value is derived from willingness to pay based VSL estimates presented in U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005. Our VSL estimate reflects income in 2005 and was converted to 2002 dollars using the GDP deflator. IEc DRAFT: May 2005 47 Chestnut, L. and R. Rowe. 1989. " Economic Valuation of Changes in Visibility: A State of the Science Assessment for NAPAP," as cited in National Acid Preparation Assessment Program, Methods for Valuing Acidic Deposition and Air Pollution Effects. NAPAP State of Science and State of Technology Report No. 27, Part B. December, as cited in Industrial Economics, Incorporated, " Initial Review of Potential Benefits Associated with Hazardous Waste Combustion MACT Standards," Memorandum, prepared for U. S. EPA, 30 April, 2002. ..

48 Chestnut, L. and R. Dennis. 1997. " Economic Benefits of Improvements in Visibility: Acid Rain Provisions of the 1990 Clean Air Act Amendments" Journal of Air and Waste Management Association 47: 395 402, as cited in Industrial Economics, Incorporated, " Initial Review of Potential Benefits Associated with Hazardous Waste Combustion MACT Standards," Memorandum, prepared for U. S. EPA, 30 April, 2002.

49 McClelland, G. et al. 1991. Valuing Eastern Visibility: A field test of the Contingent Valuation Method. Prepared for Office of Policy, Planning and Evaluation, USEPA, June, as cited in Industrial Economics, Incorporated, " Initial Review of Potential Benefits Associated with Hazardous Waste Combustion MACT Standards," Memorandum, prepared for U. S. EPA, 30 April, 2002.

50 U. S. EPA, The Benefits and Costs of the Clean Air Act 1990 to 2010, November 1999.

51 Estimates presented in The Benefits and Costs of the Clean Air Act 1990 to 2010 were expressed in year 1990 dollars. We convert to 2002 dollars using the GDP Deflator.

6 31 VISIBILITY BENEFITS Reductions in ambient PM concentrations associated with reduced PM emissions under the HWC MACT replacement standards will improve visibility in some parts of the U. S. Research has shown that individuals value visibility in the places they live and work and in places where they travel for recreational purposes. To estimate the value of recreational visibility, Chestnut and Row ( 1989) examined WTP for improved visibility in recreational settings. 47 In addition, Chestnut and Dennis ( 1997) used data representative of the Eastern United States from McClelland et al. ( 1991) to measure WTP for visibility in residential areas. 48,49 We generate high end and low end estimates of visibility benefits associated with the HWC MACT replacement standards using two different methodologies, each based on results presented in The Benefits and Costs of the Clean Air Act 1990 to 2010 ( the CAA Prospective Analysis). For the first approach, we calculated the average visibility benefits per ton of reduced PM emissions using estimates of reduced PM emissions ( 823,000 tons in 2000) and visibility improvements ($ 2.55 billion, in 2002 dollars) presented in the CAA Prospective Analysis. 50,51 Assuming that the relationship between visibility benefits and PM emissions reductions is constant, we estimated visibility benefits of $ 3,100 per ton of reduced PM emissions. We then multiplied this value by the emissions reductions expected under the HWC MACT replacement standards to generate a high end estimate of the visibility benefits associated with the replacement standards. Following this approach, we IEc DRAFT: May 2005 52 Although no quantified analysis of the proximity of facilities to Class 1 areas has been performed, facilities are distributed over a wide area including Gulf of Mexico Coast, Great Lakes, and the Mississippi which include numerous recreation areas. Also, the WTP of households for increases in residential visibility is higher than their WTP for recreational visibility. The EPA, in The Benefits and Costs of the Clean Air Act 1990 to 2010, estimated the WTP per household for residential visibility changes to be $ 141, and $ 65 to $ 137 for recreational visibility changes in National Parks ( depending on household and park location). Thus, visibility benefits are likely.

53 U. S. EPA, The Benefits and Costs of the Clean Air Act 1990 to 2010, November 1999.

6 32 estimated visibility benefits of $ 6.6 million under the Agency Preferred Approach, $ 5.2 million under the Option A and C Floors, and $ 9.3 million under the Option D Floor.

This approach has several limitations. First, the CAA Prospective Analysis values recreational visibility ( e. g., visibility for Class 1 areas, most of which are National Parks). 52 In this Assessment no quantified analysis of the proximity of facilities to Class I areas has been performed. Second, this approach assumes that visibility improvements are related to direct PM emissions only. The CAA Prospective Analysis evaluated visibility improvements associated with direct PM emissions and emissions of PM precursors ( e. g., NO x, and SO 2). Because some of the visibility improvements included in the CAA Prospective Analysis result from reduced emissions of PM precursors rather than direct PM emissions, we more than likely overestimate the visibility improvements associated with a one ton reduction in direct PM emissions. Therefore, this approach may overestimate the visibility benefits of the HWC MACT replacement standards.

Our second approach is based on the relationship between the health benefits and visibility benefits associated with reduced concentrations of ambient PM. EPA's CAA Prospective Study estimates roughly $ 87 billion to $ 137 billion ( 2002 dollars) in annual human health benefits resulting from reduced concentrations of ambient PM under the Clean Air Act. 53 Similarly, the study also estimates that the same air quality improvements would yield annual visibility benefits ranging from $ 2.6 to $ 3.7 billion. Based on these figures, we estimate a ratio of PM related visibility benefits to PM related health benefits of 0.028. Applying this ratio to the estimated health benefits associated with the HWC MACT replacement standards, we estimate that the replacement standards would generate $ 176,000 in visibility benefits under the Option A and C Floors, $ 288,000 in visibility benefits under the Option D Floor, and $ 177,000 in visibility benefits under the Agency Preferred Approach. These figures represent our low end estimates of visibility benefits associated with the replacement standards. Similar to our first approach, this approach only reflects visibility improvements in Class I areas, and it also does not distinguish between benefits associated with reduced PM emissions and benefits resulting from reduced emissions of PM precursors. IEc DRAFT: May 2005 54 Threatened and endangered species and/ or habitats were not included in the analysis.

55 A description of the eco toxicological criteria developed can be found in " Description of the SERA Methodology," Memorandum Prepared by Research Triangle Institute, Prepared for the U. S. EPA, 20 February 1998.

6 33 ECOLOGICAL BENEFITS This section compares the ecological benefits presented in the 1999 Assessment with the potential benefits associated with the HWC MACT replacement standards. Ecological benefits derived in the 1999 Assessment were based on a screening analysis for ecological risks that compared soil, surface water, and sediment concentrations with de minimis eco toxicological thresholds for adverse ecological effects. Because these thresholds represent conservative criteria for ecological risk, concentrations in excess of the eco toxicological thresholds indicate the potential for adverse ecological effects and are not necessarily indicative of ecological damages. For this reason, the 1999 Assessment discussed ecological benefits in qualitative terms.

The risk assessment's basic approach for determining whether ecosystems and/ or biota were potentially at risk consisted of five steps:

First, the risk assessment identified susceptible ecological receptors. Because combustion facilities are located in several states across the country, ecological receptors for the screening analysis were chosen to represent relatively common species and communities of wildlife. 54

Second, the risk assessment developed receptor specific eco toxicological criteria that represent acceptable pollutant concentrations ( e. g., at these levels, there is a low potential for adverse ecological effects). 55

Third, the risk assessment estimated baseline and post MACT pollutant concentrations in sediments, soils, and surface water in the areas studied.

Fourth, for each land area or water body modeled, the risk assessment compared the modeled media concentrations with ecologically protective levels to estimate eco toxicological hazard quotients.

Finally, to estimate the potential for adverse ecological effects in the study areas, the risk assessment totaled the number of polar grid zones ( for terrestrial ecosystems) and water bodies ( from aquatic ecosystems) with hazard quotients exceeding one. Exhibit 6 1 illustrates how the polar grid zones surrounding each facility are defined. IEc DRAFT: May 2005 56 The low end estimate assumed the same waterbodies or land areas are affected by different pollutants. That is, under the six square kilometers of land nearby incinerators that experienced ecological improvements associated with lead emission reductions are captured in the 87 square kilometers of land nearby incinerators associated with mercury reductions.

6 34 To assess potential ecological benefits, the risk assessment compared the surface area of land or water bodies potentially at risk in the baseline to the area of potentially at risk land and water bodies under the 1999 Standards. The difference between these numbers indicated the potential for ecological benefits under the 1999 Standards. The 1999 Assessment did not assign monetary values to these potential benefits because the data supporting the 1999 Assessment identified no clear link between hazardous quotients in excess of eco toxicological thresholds and specific benefit measures, such as increased fish populations, for which benefits transfer could assign monetary values.

Ecological Benefit Results The ecological benefit results presented in the 1999 Assessment reflect the decline in dioxin and metals emissions expected under the 1999 Standards. Lead was the only pollutant of concern for aquatic ecosystems, while mercury, dioxin, and lead were of concern for terrestrial ecosystems. The 1999 Assessment estimated dioxin emissions would fall by 29 grams per year under the 1999 Standards and that annual metals emissions would decline by approximately 100 tons. Based on these emissions reductions, the 1999 Assessment estimated that eco toxicological hazard quotients would fall below levels of concern for 38 square kilometers of water surface area under the 1999 Standards. For terrestrial ecosystems, the 1999 Assessment estimated that hazardous quotients would fall below levels of concern for 115 to 147 square kilometers of land under the 1999 standards. 56 Under the Agency Preferred Approach for the HWC MACT replacement standards, EPA anticipates a 0.40 gram reduction in dioxin emissions and a 12.5 ton reduction in metals emissions. Because these reductions are less than those associated with the 1999 Standards, ecological benefits under the replacement standards are likely to be smaller than those resulting from the 1999 Standards. However, the 1999 Assessment did not estimate the ecological benefits associated with reduced emissions from boilers and industrial furnaces. These systems were not included in the regulatory universe in 1999 but are among those facilities regulated under the HWC MACT replacement standards. Because the replacement standards represent the Agency's first attempt to limit emissions of hazardous air pollutants from boilers, ecological benefits associated with the replacement standards may be concentrated around these facilities. IEc DRAFT: May 2005 57 Although the primary pollutants which are detrimental to vegetation aesthetics and growth are tropospheric ozone, sulfur dioxide, and hydrogen fluoride, three pollutants which are not regulated in the MACT standards, some literature exists on the relationship between metal deposition and vegetation health ( Studies cited in U. S. EPA. Mercury Study Report to Congress, Volume VI: An Ecological Assessment for Anthropogenic Mercury Emissions in the United States. December 1997).

58 See, for example, Brown, T. C. et al. 1989, Scenic Beauty and Recreation Value: Assessing the Relationship, In J. Vining, ed., Social Science and Natural Resources Recreation Management, Westview Press, Boulder, Colorado, as cited in Industrial Economics, Incorporated, " Initial Review of Potential Benefits Associated with Hazardous Waste Combustion MACT Standards," Memorandum, prepared for U. S. EPA, 30 April, 2002; this work studies the relationship between forest characteristics and the value of recreational participation. For estimates of the WTP of visitors and residents to avoid forest damage, also see Peterson, D. G. et al. 1987, Improving Accuracy and Reducing Cost of Environmental Benefit Assessments. Draft Report to the US EPA, by Energy and Resource Consultants, Boulder, Colorado, as cited in Industrial Economics, Incorporated, " Initial Review of Potential Benefits Associated with Hazardous Waste Combustion MACT Standards," Memorandum, prepared for U. S. EPA, 30 April, 2002; Walsh et al. 1990, Estimating the public benefits of protecting forest quality, Journal of Forest Management, 30: 175 189, as cited in Industrial Economics, Incorporated, " Initial Review of Potential Benefits Associated with Hazardous Waste Combustion MACT Standards," Memorandum, prepared for U. S. EPA, 30 April, 2002; and Homes et al. 1992, Economic Valuation of Spruce Fir Decline in the Southern Appalachian Mountains: A comparison of Value Elicitation Methods. Presented at the Forestry and the Environment: Economic Perspectives Conference, March 9 1, 1992 Jasper, Alberta, Canada, as cited in Industrial Economics, Incorporated, " Initial Review of Potential Benefits Associated with Hazardous Waste Combustion MACT Standards," Memorandum, prepared for U. S. EPA, 30 April, 2002.

6 35 It is important to note that reducing ecological risk below levels of concern indicates the potential for ecological improvements. It is not clear that the HWC MACT replacement standards would necessarily yield ecological benefits in areas surrounding combustion facilities.

Forest Health and Aesthetics A limited number of ecological studies indicate that emissions of mercury, lead, and chlorides may damage the health and visual appearance of plants, suggesting that forest health might be adversely affected by emissions of these pollutants. 57 Although it is difficult to estimate the total value of forest health, several studies have examined its recreational value. 58 However, additional research is necessary to fully understand the effects of HAPs on forest ecosystems. Therefore, we do not quantify the forest health benefits associated with HWC MACT replacement standards in this analysis.

Productivity to Agricultural Land IEc DRAFT: May 2005 59 Vijayan, R. and S. J. Bedi. 1989. " Effect of chlorine pollution on three fruit tree species at Ranoli near Baroda, India." Environmental Pollution. 57( 2): 97 102.

60 U. S. Environmental Protection Agency, Addendum to the Assessment of the Potential Costs, Benefits, and Other Impacts of the Hazardous Waste Combustion MACT Standards: Final Rule, July 23, 1999.

61 In the long term, waste minimization may take place as companies upgrade manufacturing processes. However, increased waste management costs are only one factor in these larger decisions. We therefore do not anticipate that the replacement standards would cause a significant change in the quantity of waste combusted.

6 36 Hazardous air pollutant emissions that cause structural and aesthetic damage to vegetation may affect vegetation's growth potential. Very few studies, however, have examined the adverse agricultural productivity impacts of emissions. 59 Therefore, the potential for the HWC MACT replacement standards to enhance agricultural productivity is highly uncertain.

WASTE MINIMIZATION BENEFITS As discussed in Chapter 5, commercial combustion facilities will experience increased costs under the replacement standards. To protect their profits, these facilities will have an incentive to pass their additional costs on to customers in the form of higher combustion prices. In response to higher prices, waste generators will then have an incentive to reduce the quantity of hazardous waste that they generate. In 1999 EPA conducted a waste minimization analysis to assess the potential waste minimization impacts of the 1999 Standards. Based on the results of this analysis, we estimated that as much as 240,000 tons of waste might be reallocated to waste minimization alternatives in response to higher combustion prices. 60 In addition, this study indicated that short term waste minimization activity is not sensitive to changes in combustion pricing when prices exceed $ 165 per ton. Because current pricing is well above this threshold, we do not expect the short term waste minimization impacts of the HWC MACT replacement standards to be significant. 61 Nevertheless, short term options for waste minimization may be limited, it is likely that over the longer term ( e. g., as production systems are updated) companies will continue to seek alternatives to expensive waste management ( e. g., source reduction). To the extent that increases in combustion prices provide additional incentives to develop and adopt more efficient processes, the HWC MACT replacement standards may contribute to long term waste minimization efforts. However, we are not able to isolate and quantify the specific impact of the HWC MACT replacement standards on source reduction decisions. Moreover, an increase in waste minimization over the long run may result in other benefits not captured in this Assessment. For example, waste generators that engage in waste minimization will experience a reduction in their waste handling costs and could also reduce the risk related to waste spills and waste management. The cost of implementing waste minimization IEc DRAFT: May 2005 6 37 technology has not been assessed in this analysis. These costs are likely to at least partially offset corresponding benefits.

Exhibit 6 8 SUMMARY OF ANNUAL BENEFITS RESULTING FROM THE HWC MACT REPLACEMENT STANDARDS Benefit Category and Pollutant Monetary Value ( millions of year 2002 dollars)

Non discounted Three Percent Discount Rate Seven Percent Discount Rate Human Health Benefits Dioxin/ Furansa, b: Baseline to Option A Floor $ 0.03 $ 0.01 $ 0.00$ 0.01 Option A Floor to Agency Preferred Approach ( Option A Beyond the Floor) c $ 0.00 $ 0.00$ 0.00 $ 0.00$ 0.00 Baseline to Agency Preferred Approach ( Option A Beyond the Floor) c $ 0.03 $ 0.01$ 0.02 $ 0.00$ 0.01 Particulate Matter  Avoided Mortalityb, d Baseline to Option A Floor $ 2.84 $ 2.50 $ 2.17 Option A Floor to Agency Preferred Approach ( Option A Beyond the Floor) c $ 0.02 $ 0.02 $ 0.02 Baseline to Agency Preferred Approach ( Option A Beyond the Floor) c $ 2.87 $ 2.52 $ 2.19 Particulate Matter  Avoided Morbidity Baseline to Option A Floor $ 3.40 $ 3.40 $ 3.40 Option A Floor to Agency Preferred Approach ( Option A Beyond the Floor) c $ 0.02 $ 0.02 $ 0.02 Baseline to Agency Preferred Approach ( Option A Beyond the Floor) c $ 3.43 $ 3.43 $ 3.43 Human Health Subtotal  Agency Preferred Approach Incremental to the Baseline $ 6.32 $ 5.96d $ 5.62 Visibility Benefits:

PM related Visibility Improvements Baseline to Option A Floor $ 0.18  $ 5.18 $ 0.18  $ 5.18 $ 0.18  $ 5.18 Option A Floor to Agency Preferred Approach ( Option A Beyond the Floor) c $ 0.00$ 1.45 $ 0.00$ 1.45 $ 0.00$ 1.45 IEc DRAFT: May 2005 Exhibit 6 8 SUMMARY OF ANNUAL BENEFITS RESULTING FROM THE HWC MACT REPLACEMENT STANDARDS Benefit Category and Pollutant Monetary Value ( millions of year 2002 dollars)

Non discounted Three Percent Discount Rate Seven Percent Discount Rate 6 38 Baseline to Agency Preferred Approach ( Option A Beyond the Floor) c $ 0.18  $ 6.63 $ 0.18  $ 6.63 $ 0.18  $ 6.63 IEc DRAFT: May 2005 Exhibit 6 8 SUMMARY OF ANNUAL BENEFITS RESULTING FROM THE HWC MACT REPLACEMENT STANDARDS Benefit Category and Pollutant Monetary Value ( millions of year 2002 dollars)

Non discounted Three Percent Discount Rate Seven Percent Discount Rate 6 39 Visibility Subtotal  Agency Preferred Approach Incremental to the Baseline $ 0.18  $ 6.63 $ 0.18  $ 6.63 $ 0.18  $ 6.63 TOTAL BENEFITSd $ 6.50  $ 12.95 $ 6.14  $ 12.59 $ 5.79  $ 12.25 Notes:

a. The range of dioxin benefits reflects a lag of 21 34 years between exposure to dioxin and avoided mortality. In addition, the primary estimate of dioxin benefits presented here reflects EPA'' s current guidance on the cancer risk ( 1.5 x 105 [ mg/ kg/ day] 1) associated with dioxin/ furans. The Agency has been conducting a reassessment of the human health risks associated with dioxin and dioxin like compounds. This reassessment is currently under review at the National Academy of Sciences ( NAS). Evidence compiled from this draft reassessment indicates that the carcinogenic effects of dioxin/ furans may be as much as six times as great as believed in 1985, reflecting an upper bound cancer risk slope factor of 1 x 106 [ mg/ kg/ day] 1 for some individuals. b. The mortality related benefits presented in this exhibit reflect a mean VSL value of $ 6.2 million. This value is consistent with the VSL value used in U. S. EPA, Regulatory Impact Analysis for the Final Clean Air Interstate Rule, March 2005, adjusted for inflation and real income in 2005. c. The Agency Preferred Approach represents a beyond the floor version of the Option A Floor. d. Totals may not add due to rounding.

CONCLUSIONS As indicated in Exhibit 6 8, the Agency Preferred Approach for the HWC MACT replacement standards is expected to result in approximately $ 6.32 million in annual human health benefits and $ 177,000 to $ 6.63 million in annual visibility benefits. Specific benefits associated with the replacement standards include the following:

Avoided premature mortality. The Agency Preferred Approach is expected to reduce premature mortality by approximately 0.46 cases per year, largely because of reduced particulate matter emissions. A small fraction of these benefits result from reduced cancer risk associated with dioxin emissions.

Avoided Morbidity. Reduced PM emissions under the Agency Preferred Approach are expected to result in 7.7 avoided cases of chronic bronchitis, IEc DRAFT: May 2005 6 40 1.7 avoided hospital visits, and approximately 5,760 work loss and minor restricted activity days avoided.

Reduced risk for mercury. Reduced mercury emissions under the HWC MACT replacement standards may reduce the risk of developmental disorders in children. When humans consume fish containing methylmercury, the ingested methylmercury is absorbed into the blood and distributed to tissue throughout the body. In pregnant women, methylmercury can be passed on to the developing fetus, adversely affecting its neurological development. Children who directly consume fish with high concentrations of methylmercury may also develop neurological disorders. Therefore, to the extent that the HWC MACT replacement standards reduce methylmercury concentrations in fish, they will also reduce developmental risks for children. Because the expected reduction in mercury emissions associated with the replacement standards is small relative to total mercury emissions in the U. S., we do not expect these benefits to be significant.

Reduced lead exposure in children. The Agency Preferred Approach is expected to reduce lead exposure in children, including children of subpopulations with especially high levels of exposure ( children of subsistence fishermen, commercial beef farmers, and commercial dairy farmers). However, the small number of cases identified in the 1999 Assessment suggests that these benefits may be modest.

Potential improvement in visibility. The visibility benefits of the HWC MACT replacement standards are highly uncertain. Based on our high end and low end analyses, we estimate visibility benefits under the Agency Preferred Approach ranging from $ 177,000 to $ 6.6 million.

Potential ecological improvements. Compared to the 1999 Standards, the replacement standards are likely to produce less significant ecological benefits. That is, fewer than 38 square kilometers of water, and 147 square kilometers of terrestrial areas are expected to experience a reduction in potential ecosystem risk.

Increased forest health and aesthetics. Reduced emissions of mercury, lead, and chlorides under the HWC MACT replacement standards may improve forest health. Because additional research is necessary to fully understand the effects of these HAPs on forest ecosystems, we do not quantify the forest health benefits associated with the replacement standards. IEc DRAFT: May 2005 6 41

Increased productivity of agricultural land. Hazardous air pollutant emissions that cause structural and aesthetic damage to vegetation may also affect vegetation's growth potential. Very few studies, however, have examined the adverse agricultural productivity impacts of HAP emissions. Therefore, the potential for improvements in agricultural productivity under the replacement standards is highly uncertain.

Waste minimization benefits. The Agency Preferred Approach is unlikely to result in a significant increase in waste minimization in the short run. Over time, however, facilities may develop and adopt production technologies that reduce the generation of waste. Because of uncertainty associated with the cost and efficiency of future technologies, we do not quantify these long term impacts.

It is important to emphasize that the monetized benefits presented in this chapter represent just a portion of the total benefits associated with the HWC MACT replacement standards. We do not assign a monetary value to the ecological benefits of the rule, and in some locations these benefits may be significant. In addition, specific sub populations near combustion facilities, including children and minority populations, may be disproportionately affected by environmental risks and may therefore enjoy more significant benefits. Chapter 7 provides a more detail discussion of the environmental justice and children's health implications of the final rule.