DRAFT White Paper Asphalt (non-permitted) Strategy Evaluation Portland Air Toxics Solutions Table of Contents Introduction... 2 I. SOURCE CATEGORY: Asphalt (non-permitted)... 3 A. Source Category Description...3 A.1. Asphalt (non-permitted) in the PATS area...4 B. Modeling Results: Degree of Contribution and Emission Reductions Needed....4 C. Source Category Effect on Distribution of Emissions...4 II. SUMMARY OF EXISTING EMISSION REDUCTION STRATEGIES... 5 A. Measures...5 III. SUMMARY OF POTENTIAL NEW EMISSION REDUCTION MEASURES... 6 A. Narrative Overview of Strategies Evaluated...6 B. Summary of Strategies Evaluated...6 C. Other Measures Considered...10 IV. DETAILS FOR EACH POTENTIAL NEW EMISSION REDUCTION MEASURE... 11 A. Strategy #1: lower VOC standards for all emulsified asphalt types...11 V. ATTACHMENTS... 12 Attachment A: Considerations [To be filled out by PATSAC/DEQ]...12 Tables Table 1: 2017 modeled emissions from asphalt production and use... 4 Table 2: Blueprint and Brainstorm List Strategies... 6 Table 3: PATS Pollutants Emission Reductions from Each Strategy... 7 Table 4: Other Pollutants Reduced by Each Strategy... 8 Table 5: Summary of Strategies Evaluated: Timeframe, Technical Feasibility, and Cost... 9 Table 6: Blueprint and Brainstorm List Strategies... 12 Table 7: Effectiveness... 12 Table 8: Implementation/Feasibility Barriers... 13 Table 9: Cost Considerations... 14 Table 10: Benefits and Distribution of Benefits and Cost... 15 Page 1 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
Introduction The purpose of this document is to evaluate potential emission reduction strategies for asphalt use in the PATS study area. For the asphalt (non-permitted) source category, one strategy was evaluated. Section I describes the asphalt use source category, summarizes the modeling conclusions regarding degree of contribution of asphalt use to times above the benchmark, describes the emission reductions needed, and describes the spatial extent. Section II summarizes existing emission reduction measures. Section III provides three tables that summarize the strategy evaluation, provides an overview of emission reduction measures evaluated, and lists strategies that were considered, but not evaluated. Section IV provides a detailed narrative of the strategy and describes the strategies impact on the primary considerations as requested by the advisory committee: magnitude, timeframe, other pollutants, technical feasibility, and cost. Section V contains additional details on the full range of considerations for each strategy as requested by the advisory committee. Page 2 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
I. SOURCE CATEGORY: Asphalt (non-permitted) A. Source Category Description Asphalt area source emission inventory captures emission from solvent evaporation through nonpermitted production and use of paving and roofing asphalt. The majority of the emissions in the PATS study area come from paving asphalt therefore the white paper focuses on this activity. Asphalt is used to pave, seal, and repair surfaces such as roads, parking lots, drives, walkways, and airport runways. Asphalt concrete is grouped into three general categories: hot mix, cutback, and emulsified. Hot mix asphalt is the most commonly used paving asphalt and its use produces minimal emissions of VOCs and HAPs. Estimates for national hot mix asphalt paving emissions are about one order of magnitude lower than national estimates of cutback asphalt paving (EPA). Because emissions from hot mix asphalt are low it is excluded from the emission inventory. Cutback asphalt is used in tack and seal operations, priming roadbeds for hot-mix application, and paving operations for pavements up to several inches thick. In preparing cutback asphalt, asphalt cement is blended or cut back with a diluent. Cutback asphalt has the highest diluent content of the three asphalt categories and, as a result, emits the highest levels of VOCs per ton used. Evaporative losses are estimated at 95 percent by weight of diluent for rapid cure, 70 percent for medium cure, and 25 percent by weight of diluent for slow cure asphalt (EIIP, 2001). Emissions from asphalt paving operations occur when asphalt mixtures are applied and as they cure (see example for cutback asphalt in Figure 1). Figure 1: Percent diluent evaporated from cutback asphalt over time (EPA AP-42) Emulsified asphalt is used in most of the same applications as cutback asphalts but is a lower emitting, energy saving, and safer alternative to the cutback asphalts (Moulthrop, et al. 1997). Instead of blending asphalt cement with petroleum distillates, emulsified asphalts use a blend of asphalt cement, water and an emulsifying agent, such as soap. Since emulsified asphalt is used significantly more than cutback asphalt, emissions from emulsified asphalt account for 95% emissions from asphalt source category. Page 3 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
A.1. Asphalt (non-permitted) in the PATS area In 1999, DEQ conducted a survey of asphalt use in Oregon. Emulsified and cutback tonnage by county was obtained from the Chevron Corporation along with solvent percentages within their product, comprising most of the emulsified asphalt use in Oregon. Asphalt roofing sales data was obtained from the Asphalt Roofing Manufacturers Association. Roofing asphalt tonnage was allocated to counties using NAICS employee data. A data quality analysis was performed for all source categories. The data quality rating for other area sources, that includes asphalt use, was determined to be a D rating (acceptable). B. Modeling Results: Degree of Contribution and Emission Reductions Needed. Asphalt use is a source of volatile organic carbohydrate (VOC) emissions. One of the VOC toxics is naphthalene, which is the only PATS air toxic of concern for non-permitted asphalt category. Table 2 shows the reduction target for naphthalene in the PATS domain and contribution from the asphalt source category in 2017. The targets represent the reductions needed to meet ambient benchmark concentrations (excluding background concentrations). The reduction targets were developed based on commensurate reductions from all source sectors point, area, and mobile at top 20% receptors. Table 1: 2017 modeled emissions from asphalt production and use Times Above Benchmark More than 10 times above benchmark Pollutant Reduction Targets Percent Projected 2017 asphalt production and emissions (tons) use Naphthalene 88% 22.5 20 Contribution to 2017 total emissions by this category (%) Deleted: 4 Naphthalene emissions from use of cutback asphalt are minimal because the applications of this asphalt type are negligible. Naphthalene emissions from use of emulsified asphalt comprise 95% emissions from this category. In order to achieve the reduction targets, emission reduction strategies need to be focused on reductions from this activity. C. Source Category Effect on Distribution of Emissions Emissions from area source sectors were assigned based on the land use category that closely corresponds to the activity locations. Paving occurs in commercial, residential, and industrial land use areas. Emissions from this source category contribute (by 20%) to area wide naphthalene concentrations, although the exceedances may be even higher in localized impact areas near the asphalt paving activities. Page 4 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
II. SUMMARY OF EXISTING EMISSION REDUCTION STRATEGIES This section describes in general the controls in place based on applicable regulations, what process they affect, what pollutants are reduced and generally how effective they are. Deleted: A. Measures Federal Asphalt Processing and Asphalt Roofing Manufacture NSPS (40 CFR 60, subpart UU). This standard established limits for particulate matter that applies to saturators and mineral handling and storage processes at asphalt roofing plants that commence construction or modifications after November 18, 1980. There are no identified facilities that perform asphalt processing in the PATS area. Asphalt Processing and Asphalt Roofing Manufacture NESHAP (40 CFR 63, subpart LLLLL). This standard established limits for total hydrocarbon emissions and PM from asphalt roofing manufacturing lines. The strategy consists of capturing emissions and routing them to a combustion device, such as a thermal oxidizer, flare, boiler, or process heater to control hydrocarbon emissions. Particulate control strategies include high-efficiency air filter, fabric filter baghouses, and electrostatic precipitators. The rule applies only to major sources (none in the PATS area). Area Source Asphalt Processing and Asphalt Roofing Manufacture (40 CFR 63, subpart AAAAAAA). This regulation establishes limits for PAH (or alternatively for PM) for asphalt processing operations and roofing product manufacturing. The control strategy consists of routing roofing line vents (saturators, wet loopers, coaters, and coating mixers) to PM control devices, typically high-efficiency fiber bed filter control devices. There are three identified facilities in the PATS area that are included in the asphalt roofing manufacturing source category. The EPA published a Control Technique Guideline for the use of cutback asphalt in December 1977. The Control Technique Guideline recommended replacing cutback asphalt binders with emulsified asphalt during the ozone season. In 1979, EPA added a specification for emulsified asphalt to the Control Technique Guideline recommendations to limit the content of oil distillate in emulsified asphalt to no higher than 7 percent oil distillate. State of Oregon Division 232 (Emission Standards for VOC Point Sources). Prohibits use of medium and slow curing cutback asphalt during ozone season (April October), and prohibits use of rapid curing asphalt at any time. The rule restricts the use of emulsified asphalt as follows: the maximum solvent content by weight in the emulsified asphalt has to be between 3 and 12% depending on the grade of asphalt. The rule applies to Portland Air Quality Management Area. Division 236 (Emission Standards for Specific Industries). Requires hot-mix asphalt plants, stationary or mobile, to have collection efficiency for all dusts and gaseous effluents generated by the plant of at least 80 percent by weight. Also, particulate emissions have to be limited, and the limits are set based on the production. Deleted: Page 5 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
III. SUMMARY OF POTENTIAL NEW EMISSION REDUCTION MEASURES DEQ has evaluated one strategy for reducing emissions from asphalt use. The strategy and results of the evaluation are summarized in this section. Detailed strategy description and evaluation can be found in sections IV and V. A. Narrative Overview of Strategies Evaluated The evaluated strategy considers lowering the VOC standards for all emulsified asphalt types. The reduction targets for naphthalene emissions from asphalt paving could be closely approached if the use of emulsified asphalt is limited to that which contains 0.5 ml or less of oil distillate from a 200 ml sample (as determined using American Society for Testing and Materials (ASTM) Method D244 Test Methods for Emulsified Asphalts) regardless of application. This is equivalent to a VOC content of 0.25 percent (reduced from average 6% allowable VOC content). Similar strategy has been proposed by Ozone Transportation Commission 1 ; for details see section IV. B. Summary of Strategies Evaluated The strategy under consideration at the blueprint and brainstorm list levels is listed in Table 2. Table 3 lists the expected emission reductions for each HAP species due to the strategy. Table 4 identifies the potential benefits to reduction of ozone precursors, fine particulate, and greenhouse gas emissions. Table 5 summarizes the time frame for the emission reductions, the technical feasibility, and total cost summary. Table 2: Blueprint and Brainstorm List Strategies Blueprint Level Strategy Substitute lower emitting components Brainstorm List Strategy #1 lower VOC standards for all emulsified asphalt types to 0.25% 1 The Ozone Transport Commission (OTC) is a multi-state organization created under the Clean Air Act (CAA). The OTC is responsible for advising the Environmental Protection Agency on transport issues and for developing and implementing regional solutions to the ground-level ozone problem Page 6 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
15-PAH Acetaldehyde Acrolein Arsenic Benzene 1,3-Butadiene Cadmium Chromium VI 1,4-Dichlorobenzene Diesel PM2.5 Ethylbenzene Formaldehyde Lead Manganese Methylene Chloride Naphthalene Nickel Perchloroethylene Trichloroethylene Table 3: PATS Pollutants Emission Reductions from Each Strategy Emissions Reduced from Each Strategy In tons and (percent) Strategy #1 lower VOC standards for all emulsified asphalt types 18.6 (77) Page 7 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
Volatile Organic Compounds Ozone Precursors Fine Particulate (PM2.5) Greenhouse Gases Nitrogen Oxides Sulfur Dioxide Table 4: Other Pollutants Reduced by Each Strategy Other Pollutants Emissions Reduced Percent Strategy #1 - lower VOC standards for 77% decrease all emulsified asphalt types Notes Page 8 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
Table 5: Summary of Strategies Evaluated: Timeframe, Technical Feasibility, and Cost Blueprint level Substitute lower emitting components Strategy #1 lower VOC standards for all emulsified asphalt types Timeframe to Reduce Emissions Time needed to write and implement the rule. Technical Feasibility Low VOC alternatives are currently available. Cost Summary No additional cost to asphalt pavers. For DEQ: cost of regulation development, implementation, and enforcement. Page 9 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
C. Other Measures Considered The following measures were considered but not evaluated as a new reduction strategy. Emission standards and work practices lower applicability thresholds to include smaller sources. Emission standards and work practices use warm asphalt. This strategy was not evaluated because this is a new technology and DEQ does not have enough information to evaluate. Reduce use permeable/porous pavement, concrete roads, and use of recycled asphalt. This strategy has a potential to reduce pollution. However, at this point, we are not able to quantify the potential emission reductions with these measures. Reduced studded tire use to help decrease the frequency of paving operations. Require the same VOC limit on seal coats as for asphalt paving. Page 10 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
IV. DETAILS FOR EACH POTENTIAL NEW EMISSION REDUCTION MEASURE The five primary considerations below are from the PATSAC Considerations List. (reference: http://www.deq.state.or.us/aq/toxics/docs/pats/3_2_11regroupedconsideraton.pdf) A. Strategy #1: lower VOC standards for all emulsified asphalt types Narrative Overview The strategy limits the VOC content of emulsified asphalt to 0.5 ml of oil distillate from a 200 ml sample (as determined using American Society for Testing and Materials (ASTM) Method D244 Test Methods for Emulsified Asphalts). This is equivalent to a VOC content of 0.25 percent (OTC, 2007). Limits on VOC content for emulsified asphalt vary by state. For example, California limits VOC content to 3% (R4-26) while Delaware bans the use of emulsified asphalt that contains any VOC (Reg. No. 24, Section 34). This strategy recommendation is based on technical analysis done by Ozone Transport Commission (OTC, 2007). Primary Considerations a. Magnitude of Reductions. Emission reductions are calculated based on 2017 emission inventory assuming the average VOC content of emulsified asphalt is 6%. Assuming VOC limit of 0.25% the resulting reductions would be 96%. EPA default rule penetration of 80% when applied to this estimate gives reduction of 77%. b. Timeframe to Implement. Rule adoption 1-2 years after which the emission reductions would be measured immediately. c. Other pollutants reduced. VOC reduction has potential to reduce ozone precursors. d. Technical feasibility. Low VOC alternatives are currently available. e. Cost. No additional cost is expected for asphalt pavers from the use of low VOC alternatives. For DEQ, there would be the cost of regulation development, implementation, and enforcement. Page 11 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
V. ATTACHMENTS Attachment A: Considerations [To be filled out by PATSAC/DEQ] This list of considerations will be used by PATSAC as an informal tool to understand toxics reduction strategies. If the committee chooses, it may also use these considerations to shape its recommended package of strategies or implementation steps. The tables below are cross-walked to the Committee s Considerations reference (DEQ web link below). For example, in Table 7, consideration 1.c. Effect on Exposure, refers to consideration 1.c in the Committee s full considerations list. Considerations (reference: http://www.deq.state.or.us/aq/toxics/docs/pats/3_2_11regroupedconsideraton.pdf) Table 6: Blueprint and Brainstorm List Strategies Blueprint Level Strategy Brainstorm List Strategy #1 [write full description from list] Table 7: Effectiveness Strategy 1.c. Effect on Exposure 2 1.d. Pollution Prevention 3 #1 2 Effect on exposure: How well does the measure target spatial extent of the emissions? Some reductions may have more pronounced effects on localized concentrations; others may do more to reduce pollutants area-wide. (OAR 340-246-0170 4(g)). Ability to address short term or acute exposures if relevant. 3 Pollution prevention: Where does the strategy fit in the pollution prevention hierarchy? 1. Modify the process, raw materials, or product to reduce the quantity and toxicity of air contaminants generated. 2. Capture and reuse air contaminants. 3. Treat to reduce the quantity and toxicity of air contaminants released. (OAR 340-246-0050) Page 12 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
Table 8: Implementation/Feasibility Barriers Strategy 2.a. Legal Authority 4 2.c. Funding 5 Implementation 6 2.e. Acceptance 7 Approaches 8 2.d. 2.f. Non-regulatory #1 4 Legal authority: Does the measure fall under existing regulations or are new laws/ rules required? Does federal pre-emption preclude new laws/rules? Is/will the proposed measure be addressed through other planned Federal, state, or local rulemaking or other processes? 5 Funding: What is the cost to DEQ or other agency to implement the measure? How could the agency cost be funded? How certain is the funding mechanism? 6 Implementation: Is there a ready structure for implementation or ability to coordinate with existing programs? 7 Acceptance: Is there public and stakeholder support for the measure? 8 Non-regulatory approaches: Could the measure be implemented through incentives or education? Is there an opportunity to implement the measure through a community-based multi-stakeholder collaborative process? Could the measure begin as voluntary and later become mandatory as necessary in a contingency plan? Page 13 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
Table 9: Cost Considerations Strategy #1 3.b. Cost Effectiveness 9 3.c. Other Environmental Impacts 10 3.d. Energy 11 3.e. Public Safety 12 3.f. Indirect Economic Costs 13 9 Cost effectiveness: What is the cost per unit of air toxics reduced? 10 Other environmental impacts: Potential for the emission reduction measure to transfer pollutants to soil or water, or cause harm to human health or the ecosystem. 11 Energy: Effect of measure on energy use. 12 Public safety: What is the affect of the measure on public safety? For example, would emission reductions restrict activities related to adequate lighting, heat, ventilation, signage or access to emergency services? 13 Indirect economic costs: What are the potential indirect costs to communities, the local economy or business sectors? Page 14 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions
Table 10: Benefits and Distribution of Benefits and Cost Benefits Distribution of Benefits and Cost Strategy 4.a. Health 14 4.b. Livability 15 Economic Benefits 16 Distribution 17 Distribution 18 4.c. Indirect 5.a. Risk 5.b. Cost #1 14 Health: What are the health benefits of meeting the benchmarks? This could be measured as the number of cancer cases avoided and/or value of statistical life and medical costs avoided. 15 Livability: Improved quality of life associated with improved nuisance conditions such as odor or noise. 16 Indirect economic benefits: What are the potential benefits to communities, the local economy or business sectors? 17 Risk distribution: Could the measure change the social distribution of risk in the PATS area, i.e. sensitive populations and environmental justice communities? 18 Cost distribution: Could the measure impose disproportionate costs or economic impacts to environmental justice communities in the PATS study area? Page 15 of 15 DRAFT Asphalt non-permitted White Paper Portland Air Toxics Solutions