Best available control technology (BACT) requirements

1. Best available control technology (BACT) requirements Candace Carraway, OAQPS Draft August 2013

2. Major Topics • When does BACT apply • Steps in the “Top Down” BACT analysis

3. Best Achievable Control Technology (BACT) Overview • Pollutant specific emissions limit, case-by-case • Takes into account energy, environmental, or economic impacts • Limit must be at least as stringent as applicable: • New Source Performance Standard (NSPS) and/or • National Emission Standard for Hazardous Air Pollutants (NESHAP) • Selected by “Top Down” BACT analysis • Identify all available control technologies • Eliminate technically infeasible control options • Rank remaining control technologies by its effectiveness (considering economic, energy and environmental impacts) • Evaluate most effective controls and document results • Select BACT

4. BACT is One of the Main PSD Program Requirements • Main requirements: • Install Best Available Control Technology (BACT) • Perform air quality analysisto assess impacts on air quality • Performclass I area analysis toassess impacts onnational parks and wilderness areas • Perform additional impacts analysis • Provide opportunities for public involvement

5. BACT Applicability • Identify emissions units that are subject to BACT • Applies to each individual new or modified affected emissions unit or activity at which a net emissions increase would occur • Perform BACT analysis at each of the applicable emissions units for each regulated pollutant subject to PSD review • Provide example to show that BACT determination must separately address each applicable unit for each regulated pollutant

6. BACT Analysis Step 1 • Identify all available air pollution control technologies, regardless of cost • Information sources: • Review RACT/BACT/LAER Clearing House http://cfpub1.epa.gov/RBLC/ • Look at BACT and LAER • Control technology vendors • Federal/state/local NSR permits • Environmental consultants • Technical journals (e.g., Journal of Air and Waste Management Association) and air pollution conferences • Other?

7. BACT Analysis Step 1 (continued) • Include technologies used outside the US • Include controls applied to similar categories and gas streams • Review applicable NSPS and NESHAP (including MACT), which define the minimal “floor” for BACT • Consider • Inherently lower-emitting processes/practices (give example) • Add on controls (e.g., scrubbers, fabric filters) • Combination of inherently lower-emitting processes/practices and add on controls (give example)

8. BACT Analysis Step 1 (continued) • EPA has not considered the BACT requirement as a means to redefine the design of a source when considering available control technology • EPA does not require coal-fired electric generators to consider gas-fired electric turbines • CO position on this issue

9. Class exercise • Instructor to present a scenario that is based on your experience, using a one paragraph description of the source similar to the example in the NSR workshop manual, page B.15. Class could be asked to go to the RBL Clearinghouse to find control options. You could finish the exercise by comparing the class’s list with the list supplied by the applicant.

10. BACT Analysis Step 2 • Eliminate technically infeasible control options • Source must demonstrate technical infeasibility, based on physical, chemical, and engineering principles • If someone has issued a permit requiring a certain technology or emission limit, it is assumed that the technology or limit is technically feasible

11. BACT Analysis Step 2 (continued) • Where control technology has not been installed and operated successfully on the type of source under review, feasibility is determined based on: • Availability (i.e., the product has reached the licensing and commercial sales stage of development) • Applicability • the control alternative has been or is soon to be deployed on the same or a similar source type, or • Could be used on the source based on the physical and chemical characteristics of the pollutant-bearing gas stream

12. BACT Analysis Step 2 (continued) • Applicant may show technical infeasibility through an unresolvable technical difficulty with applying the control (e.g., size of the unit, location of the propose site, and operating problems related to specific circumstances of the source) • Applicant may not use cost to demonstrate infeasibility, but this may be considered in the economic impacts portion of BACT analysis

13. BACT Analysis Step 2 (continued) • Present to class an example from your experience of a control alternative that the source thought was infeasible • Ask class to analyze • Discuss your agency’s analysis of the issue • Provide another couple of examples briefly where the control alternative was not feasible

14. BACT Analysis Step 3 • Rank remaining control technologies according to control effectiveness. For each pollutant, list includes: • Control efficiency (percent of pollutant removed) • Expected emissions reduction (tons/year) • Economic Impacts • Environmental Impacts (e.g., significant impact on surface water) • Energy Impacts

15. BACT Analysis Step 3 -Control Efficiency • Two key questions: • How to compare oranges to oranges (deciding the common unit to use in comparing the emissions of each option) • How to analyze control techniques that can operate over a wide range of emission performance levels • Tips on what to watch for, based on practical experience • Major issues you have seen in this area

16. BACT Analysis Step 3 - Expected Emissions Reductions (tons/year) • Calculate annual emission projections for each option using standard PTE approach • Options are ranked with the top spot going to the control technology option that achieves the lowest emissions level, in descending order of emissions control effectiveness

17. BACT Analysis Step 3 – Economic and Other Impacts • Applicant prepares a chart to display the top-down ranking, and for each alternative includes data on: • Economic impacts • Environmental impacts • Energy impacts

18. BACT Analysis Step 3 – Economic Impacts • Economic impacts include • Average cost effectiveness (dollars per ton of emissions reduced) based on data from similar sources • incremental cost effectiveness • Affordability to the source is not as relevant as the average and incremental cost effectiveness • Where control technology has been successful for similar sources, applicant would need to document significant cost differences for its source in order to eliminate the control alternative

19. BACT Analysis Step 3 – Economic Impacts • Key issues for cost effectiveness • Ensure that the design parameters used in cost estimates are consistent with emissions estimates used in other portions of the PSD application (e.g., dispersion modeling inputs and permit emission limits) • Provide example • Where would a reviewer find this information for comparison • Ask for more detailed cost data if cost projections appear excessive in light of recent cost data

20. BACT Analysis Step 3 – Economic Impacts • Average cost effectiveness • Total annualized costs of control, divided by • Annual emission reductions (the difference between the baseline emission rate and the controlled emission rate) • Major issues to look for in this area

21. BACT Analysis Step 3 – Economic Impacts • Incremental cost effectiveness compares costs and emissions performance level of a control option to the next most stringent option • Calculation: • Total annualized cost of option 1 minus total annualized cost of option 2 (less stringent option), divided by • Option 2 emission rate minus option 1 emission rate • Work through an example • Identify major issues for review based on your experience

22. BACT Analysis Step 3 – Environmental Impacts • Environmental impacts should include • any significant or unusual other media impacts (e.g., water or solid waste) • Usually limited to discharges with potential for causing adverse environmental effects • Quantify mass and composition of discharges and consequences of release • Impacts on ground water and local surface water; whether applicable water quality standards will be met; availability/effectiveness of mitigation techniques • Quality and quantity of solid waste to be stored, disposed of or recycled (including permeability, water retention, leachability, hazardous characteristics, etc.) • Irreversible or irretrievable commitment of resources (e.g., scarce water resources) • Significant differences in noise levels, radiant heat, dissipated static electrical energy and greenhouse gas emissions

23. BACT Analysis Step 3 – Environmental Impacts • Environmental impacts should include the relative ability of each control alternative to control emission of HAPs and visibility impacts • Examples where environmental factors have made a difference in a BACT analysis • Environmental concerns become important when site-specific receptors exist • Application to tribal issues?

24. BACT Analysis Step 3 – Energy Impacts • Generally consider only direct energy consumption of alternative control technologies • Quantify any benefits or penalties • Typically can monetize these impacts and factor them into the economic impacts analysis

25. BACT Analysis Step 4 • Evaluate most effective controls based on all the factors in step 3 and document results

26. Review of Sample Top-Down BACT Impact Analysis Chart • Put the whole picture in front of the class via a chart using the most simple real life example you can find • Ask class to get into small groups; each group to make a recommendation on BACT • Discuss results

27. BACT Analysis Step 5 • Ultimate BACT decision is made by the permitting agency after public review • BACT is based on the most effective control option for which an adequate justification for rejection was not provided • Public gets at least 30 days to review draft permit • Discuss practical advice for reviewers • Permitting agency will consider any new information that may come to light during the comment period, including recent permit decisions

28. Implementing BACT • BACT is an emission limit that: • Is needed for each emission unit at the source that is subject to PSD for each pollutant subject to review that is emitted by the source • Must be met on a continual basis at all levels of operation (e.g., limits written in pounds/MMbtu or percent reduction achieved) • Must protect short term ambient standards (limits written in pounds/hour) • Must be enforceable as a practical matter

29. Implementing BACT • BACT can be made more stringent if BACT would result in exceedence of a NAAQS or a PSD increment

30. Summary • Major stationary sources and major modifications that are subject to PSD must conduct a BACT analysis • Each BACT analysis is case-by-case and is based on evaluation of all available control technologies • Alternatives are ranked in descending order of control effectiveness • The most stringent or top alternative is BACT unless the applicant demonstrates that technical considerations or energy, environmental or economic impacts justify the elimination of the control option