Date: December 7, 2004 ( Revised April 12, 2005)

Subject: Procedures for Determining Emissions from Plywood and Composite Wood Products Process Units for Low risk Demonstrations EPA Contract No. 68 D 1 079; EPA Work Assignment No. 3 04 RTI Project No. 08550.003.004 From: Katie Hanks, Kristin Parrish, and David Randall To: Mary Tom Kissell, ESD/ WCPG ( C439 03) U. S. Environmental Protection Agency Research Triangle Park, NC 27711 I. Introduction Final national emission standards for hazardous air pollutants ( NESHAP) were promulgated by the Environmental Protection Agency ( EPA) Administrator for the plywood and composite wood products ( PCWP) source category on July 30, 2004 ( 40 CFR part 63, subpart DDDD). The NESHAP applies to PCWP manufacturing facilities that are located at major sources of hazardous air pollutant ( HAP) emissions, except for facilities the EPA determines are part of the de listed low risk subcategory of PCWP manufacturing facilities. To become part of the low risk subcategory and not be subject to the requirements of subpart DDDD, facilities must submit a low risk demonstration, as specified in appendix B to subpart DDDD, for EPA approval. Following signature of the final PCWP rule, industry stakeholders raised concerns regarding the emission testing requirements specified in Appendix B to subpart DDDD. This memorandum explores the merits of the stakeholders' concerns.

Section II of this memorandum outlines the stakeholders' concerns with the Appendix B testing requirements. Section III provides an assessment of the stakeholders' concerns. Section IV describes recommended emission estimation procedures for selected process units. Section V presents a summary of the recommended procedures for determining HAP emissions for possible inclusion in an amendment of Appendix B to subpart DDDD. It is helpful to refer to the summary tables in Section V while reading this memorandum. 2 II. Stakeholders' Concerns with Appendix B Testing Requirements Prior to promulgation of the final rule, the EPA determined that the majority of the risk at PCWP affected sources is accounted for by the following 13 HAP: acetaldehyde, acrolein, benzene, arsenic, beryllium, cadmium, hexavalent chromium, lead, nickel, formaldehyde, phenol, manganese, and methylene diphenyl diisocyanate ( MDI). Therefore, Appendix B limits the list of HAP that must be included in the low risk demonstration to these 13 HAP. Table 1 summarizes the process units that must be tested for each HAP if a PCWP source seeks to become part of the low risk subcategory and the emissions test methods specified in Appendix B, as promulgated, for each HAP. 1 Table 1. Emissions test methods specified in Appendix B, as promulgated.

HAP Process units Specified test method( s)

Acetaldehyde, acrolein, formaldehyde, phenol All process unitsa  NCASI IM/ CAN/ WP 99.02  EPA M320 or ASTM D6348 03 Benzene All process unitsa  EPA M320 or ASTM D6348 03 MDI Presses that process board containing MDI resin  EPA M320  Conditional Test Method 031 Arsenic, beryllium, cadmium, chromium, lead, nickel, manganese Direct fired process unitsb  EPA M29 MDI = methylene diphenyl diisocyanate aAs promulgated, Appendix B requires emissions testing for all PCWP process units ( i. e., testing is not limited to the process units with control or work practice requirements defined in subpart DDDD). bThe potential for HAP metals emissions from direct fired process units originates from combustion.

Stakeholders have expressed concern about the number of emissions tests that are required by Appendix B ( as promulgated) if a source chooses to do a low risk demonstration and the resources associated with conducting and reviewing these emissions tests. The stakeholders stated that emissions testing is not feasible or necessary for every process unit. The stakeholders stated that many PCWP process units are not configured for emissions testing and that testing of every type of PCWP process unit ( especially those with what they claim are insignificant emissions) is not reasonable. 2,3,4 In addition, the stakeholders stated that requiring emissions testing for acrolein and benzene from all PCWP process units is not justified by the available data that show that emissions of acrolein and benzene are frequently not detected in the exhausts from many types of PCWP process units. 2,5 The stakeholders requested that the National Council of the Paper Industry for Air and Stream Improvement ( NCASI) Method IM/ CAN/ WP 99.02 be listed in Appendix B to subpart DDDD for measurement of benzene as well as for measurement of acetaldehyde, acrolein, formaldehyde, and phenol. They also requested that EPA Method 18 be allowed for benzene testing. The stakeholders also suggested that only one of multiple identical dryers at a facility would need to be tested ( e. g., only one of three identical veneer dryers) and that the emissions data from the one dryer tested could be applied to the other identical dryers. The stakeholders further suggested that only one of multiple identical process 3 units from separate facilities within the same company would need to be tested. Finally, stakeholders stated that HAP metals emissions testing is not necessary for direct fired process units using only natural gas. 21 III. Assessment of Stakeholder's Concerns A. Process Units to Be Considered in Low risk Demonstration 1. Background Information and Issues Table 1 of the preamble to the final PCWP rule ( provided in Attachment 1) lists most of the PCWP process units for which maximum achievable control technology ( MACT) determinations were made under the PCWP NESHAP. The final PCWP rule ( subpart DDDD) does not contain definitions for all of the process units listed in Table 1 of the preamble; only those process units with control or work practice requirements are defined in subpart DDDD. Even though some process units are not specifically defined in subpart DDDD, all of the process units listed in Table 1 of the preamble to the final rule are part of the PCWP affected source ( as defined in subpart DDDD), and Appendix B requires testing of all of the process units within the affected source if the source wishes to become exempt from section 112. Other ( less common) process units that are not listed in Table 1 of the preamble to the final rule are also part of the PCWP affected source ( e. g., paddle type particle dryers, bagasse fiberboard mat dryers, veneer kilns, particleboard press molds, and particleboard extruders). These processs units were considered in the MACT development process and are required to be considered in the low risk demonstration. 6 Stakeholders suggested that EPA eliminate from the Appendix B emissions testing requirements those process units that do not emit " significant quantities" of the HAP listed in Appendix B, or that generally emit them at less than 1 part per million ( ppm) ( the limit of detection that the stakeholders believe to be established by the final rule). 2 Because the low risk demonstrations are to be based on the cumulative risk from all process units within each PCWP affected source, emissions from each process unit must be considered in the low risk demonstration, regardless of how insignificant these emissions may seem. For example, inclusion of the emissions from four types of process units at a facility may bring the facility to the edge of the low risk criteria, and emissions from other types of process units ( with seemingly insignificant emissions) could render the facility non low risk. However, if the emissions from process units ( with seemingly insignificant emissions) were not considered, then the facility would be considered low risk even though emissions from all process units were not accounted for. Also, given the high exhaust flow rates characteristic of many PCWP process units, it should be noted that 1 ppm is not necessarily an insignificant amount of HAP. For example, a process unit with an exhaust flow rate of 50,000 dry standard cubic feet per minute ( dscfm) emitting 1 ppm of benzene would be emitting over 2 tons of benzene per year ( assuming the unit operates 8,000 hours per year [ hr/ yr]). 4 Furthermore, there appears to be a misconception among stakeholders regarding the 1 ppm criteria for test method detection limits ( MDL). Appendix B states that facilities may treat emissions of an individual HAP as zero if all of the test runs result in a non detect measurement and the MDL is less than or equal to 1 part per million, dry volume basis ( ppmvd) for pollutant emissions measured using EPA Method 320; NCASI Method IM/ CAN/ WP 99.02 ( NICM), or ASTM International ( ASTM) D6348 03. Otherwise, non detect data for individual HAP must be treated as one half of the method detection limit. The 1 ppm criteria for non detects is not an applicability limit below which emissions from process units are disregarded for subpart DDDD or Appendix B. Concentration based applicability cutoffs were rejected by EPA prior to promulgation ( see section 2.6.5 of the promulgation comment response document). 7 Emissions from process units may be considered to be zero only if all of the test runs result in non detect measurements and the MDL was less than 1 ppm.

2. Recommendations We recommend that emissions from each type of process unit ( that could potentially emit any of the HAP listed in Appendix B) continue to be considered in the low risk demonstration through emissions testing or estimation, depending on the technical feasibility of emission testing. Given that the purpose of the low risk demonstration is to certify that a PCWP affected source poses insignificant risk to human health and the environment, and therefore, is eligible to become exempt from MACT compliance and section 112 regulation, emissions test data are preferable to emissions estimates when emissions test data can be obtained. We also recommend that a table be included in Appendix B which lists each type of process unit and indicates whether emissions testing is required or if emissions estimation is to be allowed as an option. Suggested definitions for process units that are not defined in subpart DDDD are presented in Attachment 2.

The following sections ( a through d) explore the feasibility of emissions testing for four classes of process units: ( a) process units with control requirements under subpart DDDD, ( b) process units without control requirements, but having work practice requirements under subpart DDDD, ( c) process units without control or work practice requirements under subpart DDDD, and ( d) other process units not listed in Preamble Table 1. When determining the feasibility of emissions testing, our primary considerations were how to most accurately account for emissions and whether the process units in each group are commonly configured to allow emissions testing. Process units that are not configured for emissions testing would require reconfiguration ( if possible) before testing so that flow rates and emissions could be measured accurately. Such reconfigurations could be time consuming and costly given that multiple process units of each type are usually located at a single facility. For many process units ( i. e., those with relatively low emissions of Appendix B HAP), reconfiguring the process units and conducting emissions testing often would not result in an emission rate more significant ( for purposes of the low risk demonstration) than an emission rate that could be generated using available emission estimation techniques. We recommend that all process units be considered in the low risk demonstration; however, we acknowledge that lower emitting process units will have less impact on the risk demonstration. Although process units were evaluated based on the technical feasibility of testing and not based on their potential emissions, we note that generally the lower emitting process units 5 have not been the subject of control requirements and are less likely to be configured for emissions testing. For the most part, the process units that drive risk are configured for emissions testing and are recommended for testing in this memorandum.

a. Process units with control requirements under subpart DDDD Subpart DDDD contains emissions control requirements for the following types of process units:

fiberboard mat dryer heated zones green rotary dryers hardboard ovens press predryers pressurized refiners primary tube dryers secondary tube dryers reconstituted wood product board coolers reconstituted wood product presses softwood veneer dryer heated zones rotary strand dryers conveyor strand dryer zones one and two Emissions testing is feasible for these types of process units. Emissions testing is also feasible for the remaining zones of conveyor strand dryers and fiberboard mat dryers. However, the cooling zones of softwood ( and hardwood) veneer dryers have multiple emission points that are often not configured for emissions testing, and therefore, emission estimation is recommended for veneer dryer cooling zones in section IV. A. 13. It is also not practical to measure fugitive emissions from fiberboard mat dryers or softwood veneer dryers; estimates of fugitive emissions from these dryers are discussed in section IV. A. 13.

b. Process units without control requirements, but having work practice requirements under subpart DDDD Subpart DDDD does not require emissions tests for process units that have work practice requirements but no control requirements. There are three types of PCWP process units that have work practice requirements only under subpart DDDD: dry rotary particle dryers, veneer redryers, and hardwood veneer dryers. The primary difference in these three types of process units and their counterparts with subpart DDDD control requirements ( i. e., green rotary dryers and softwood veneer dryers) relates to how the units are operated. With the exception of radiofrequency ( RF) heated veneer redryers, emission testing is feasible for process units with work practice requirements. Therefore, we recommend that emissions testing be required in Appendix B for dry rotary dryers, veneer redryers ( heated by conventional means), and hardwood veneer dryer heated zones. By definition in subpart DDDD, veneer redryers do not include veneer redryers that are heated by RF. We recommend that emission estimation procedures ( discussed in section IV. A. 14) be allowed for RF heated veneer redryers because these units typically are not configured for emissions testing.

c. Process units without control or work practice requirements under subpart DDDD 6 A number of PCWP process units without subpart DDDD control or work practice requirements have not been the subject of organic emissions control requirements and often are not configured for emissions testing. Process units that do not have control or work practice requirements under subpart DDDD include:

softwood plywood presses sanders hardwood plywood presses saws engineered wood products presses fiber washers humidifiers chippers atmospheric refiners log vats formers lumber kilns blenders storage tanks rotary agricultural fiber dryers wastewater operations agricultural fiber board presses stand alone digesters miscellaneous coating operations ( including group 1 miscellaneous coating operations)

We believe it would be appropriate to allow emissions estimates for those process units that typically are not configured ( and often cannot be readily configured) for emissions testing, except as otherwise specified below. The feasibility of testing each type of process unit is discussed below.

Miscellaneous coating operations. Information on the types of miscellaneous coatings used at PCWP plants was collected through the MACT survey. Available information on the content of coatings applied during miscellaneous coating operations ( as defined in subpart DDDD) indicate that Appendix B HAP are not emitted from these coating operations. 6,8 Therefore, we recommend that all miscellaneous coating operations be excluded from consideration under Appendix B.

Agri board rotary dryers and presses. No emissions data are available for rotary agricultural fiber dryers and agricultural fiber board presses. However, MDI resin is commonly used to produce agriboard, so some MDI could be emitted from agricultural fiber board presses. Furthermore, if agricultural fiber dryers are direct fired ( as is common for rotary dryers), then they could possibly emit HAP metals as a result of fuel combustion. We are not aware of any unusual equipment configurations that would make testing difficult for rotary agricultural fiber dryers and agricultural fiber board presses. Therefore, we recommend that Appendix B continue to require emissions testing for rotary agricultural fiber dryers and agricultural fiber board presses.

Atmospheric refiners. Atmospheric refiners are used by medium density fiberboard ( MDF), hardboard, fiberboard, and particleboard plants. We recommend that emissions testing continue to be conducted for atmospheric refiners because these units are amenable to emissions 7 testing. Available emissions data show that all of the Appendix B organic HAP except MDI have been detected in atmospheric refining operations. We recommend that MDI and HAP metals testing not be required for atmospheric refining operations. MDI is not used in atmospheric refining operations, and there is no mechanism for HAP metals formation.

Hard to test process units. Except as noted above, other process units without control or work practice requirements in subpart DDDD are difficult to test. These hard to test process units include:

softwood plywood presses hardwood plywood presses engineered wood products presses humidifiers formers blenders sanders saws fiber washers chippers log vats lumber kilns storage tanks wastewater operations stand alone digesters Some of these process units are vented primarily for dust control and reclaim of process materials, and their venting systems are not designed for flow measurement or measurement of organic gases. Some of the process units are not vented ( i. e., are fugitive emissions sources) or are only partially vented. The configuration of these process units, in terms of how and if they vent to the atmosphere, varies significantly from plant to plant, and only a small number of the process units across the U. S. are configured for emissions testing. 2,9 Often, the emission points from these process units ( where discernable emission points exist) are not configured such that EPA Method 1 and/ or 2 ( 40 CFR 60, Appendix A) criteria for selection of sampling ports and measurement of gas velocity could be met. Emissions data are available from an extensive emissions testing program where testable units in several of the process unit groups were identified. These emissions data ( along with other available data collected during NESHAP development) have been used to develop emission factors. 10 We recommend that these emission factors be used to estimate emissions from the hard to test process units for purposes of the PCWP low risk demonstrations. Sections IV. A. 1 through 9 discuss recommended emission factor estimation procedures. Other emissions estimation methods are recommended for hard to test process units for which no emission factors are available ( see sections IV. B. 1 through 3).

d. Other process units not listed in Table 1 of the final preamble A MACT determination was made for several non traditional PCWP process units that were not listed in Table 1 of the preamble to the final rule, including paddle type particle dryers, bagasse fiberboard mat dryers, veneer kilns, particleboard press molds, and particleboard extruders. Of these process units, veneer kilns, particleboard press molds, and particleboard extruders are likely hard to test. Emission estimation procedures for veneer kilns, particleboard press molds, and particleboard extruders are discussed in sections IV. A. 11 through 12. 8 Paddle type particle dryers and bagasse fiberboard mat dryers are expected to emit some HAP, however, no emission factors are available for these process units. It is expected that these units could be configured for emissions testing. Therefore, we recommend that emissions testing be required for paddle type particle dryers and bagasse fiberboard mat dryers.

There may be additional ancillary PCWP processes for which no HAP data are available and MACT determinations were not made ( e. g., log storage piles, material handling operations). No information is available to conclude that there are Appendix B HAP emissions from other PCWP processes not mentioned elsewhere in this memorandum. Nevertheless, in the event that there may be an additional HAP emission source within the PCWP affected source that the facility is aware of but has not been accounted for by EPA, we recommend that a category of " other ancillary processes that may emit Appendix B HAP emissions" be added to Appendix B and that engineering estimates for all of the Appendix B HAP be required for such processes. To prevent unnecessarily broad interpretation of the " other ancillary processes that may emit Appendix B HAP emissions" category, EPA may wish to consider development of a list of insignificant activities that need not be included in the low risk demonstration. In order to develop such a list, it would be helpful to know what activities States consider to be insignificant for HAP emissions and/ or to have some data or rationale explaining why none of the Appendix B HAP would be expected from certain activities.

B. Testing for Benzene and Acrolein 1. Use of NCASI Method IM/ CAN/ WP 99.02 and EPA Method 18 for benzene testing Stakeholders requested that the NCASI Method IM/ CAN/ WP 99.02 be listed in Appendix B to subpart DDDD for measurement of benzene as well as for measurement of acetaldehyde, acrolein, formaldehyde, and phenol. Following proposal of the PCWP rule, commenters requested that EPA replace references to NCASI Method IM/ CAN/ WP 99.01 in subpart DDDD ( for measurement of acetaldehyde, acrolein, formaldehyde, methanol, phenol, and propionaldehyde) with the revised version of the same method ( NCASI Method IM/ CAN/ WP 99.02). The EPA reviewed the NCASI Method IM/ CAN/ WP 99.02 for applicability with respect to the six HAP named in subpart DDDD and concluded that NCASI Method IM/ CAN/ WP 99.02 was appropriate for measurement of these six HAP. Prior to promulgation, EPA did not review NCASI Method IM/ CAN/ WP 99.02 with respect to benzene, and therefore, EPA did not list NCASI Method IM/ CAN/ WP 99.02 in Appendix B to subpart DDDD as an applicable method for measurement of benzene. Upon receipt of additional information and further review of the method, EPA agreed that it is appropriate for measurement of benzene and plans to amend Appendix B to subpart DDDD to allow use of NCASI Method IM/ CAN/ WP 99.02 for benzene measurement. 12 Stakeholders also requested that EPA Method 18 ( 40 CFR part 60, appendix A) be included in Appendix B to subpart DDDD for benzene measurement. 21 The EPA has agreed that Method 18 is appropriate for measurement of benzene and plans to amend Appendix B to subpart DDDD accordingly. 9 2. Reducing benzene and acrolein testing requirements Appendix B allows a process unit to be excluded from the testing requirements for benzene or acrolein for purposes of the low risk demonstration when EPA determines it will not emit detectable amounts of benzene or acrolien, respectively. Elsewhere in this memorandum, we recommend that emissions estimation ( as opposed to emissions testing) be allowed for many hardto test process units. If all of the available benzene and acrolein data are non detect for these hard to test units ( as is generally the case), then consideration of benzene and acrolein is not required for these process units ( see section IV. A for details).

The discussion of benzene and acrolein testing in this section is limited to those process units for which emission testing is recommended. Also, as noted in the previous sub section, EPA has decided to propose to revise Appendix B to allow benzene measurement with NCASI Method IM/ CAN/ WP 99.02. Thus, the burden associated with benzene measurement will likely be reduced somewhat because a separate test method would no longer be required.

Table 2 lists the process unit groups with recommended Appendix B emission testing requirements and notes whether acrolein or benzene have been detected from the process unit group. Benzene and acrolein have been detected on a few occasions from most of the process unit groups. The size of the available data sets vary according to process unit type. The size of the data set should be considered when deciding if acrolein or benzene may be emitted from the entire population of each type of process unit ( including those that have not been tested previously). For example, as of April 2000, there were 303 softwood veneer dryers in the U. S.; however, acrolein and benzene data are available for the heated zones of only 22 softwood veneer dryers. 6 We recommend that emissions testing for benzene and acrolein continue to be required for all of the process units listed in Table 2 for the following reasons:

( 1) Most of the process unit groups had at least some scattered detects, and the number of process units tested was much lower than the number of existing process units. Thus, the available data do not allow one to conclude that benzene and acrolein would not be emitted for a given process unit type. Although there are no data for some process unit types, the available data for similar process units indicate that benzene and acrolein could reasonably be expected to be emitted from the process units.

( 2) Unlike the hard to test process units for which emissions estimates are recommended, the process units listed in Table 2 are amenable to emissions testing.

( 3) Requiring testing for benzene and acrolein is not likely to substantially increase the overall testing burden for these units. The process units listed in Table 2 would be tested for acetaldehyde, formaldehyde, and phenol under subpart DDDD and/ or the low risk demonstration. Benzene and acrolein can be measured with the same test method used to test these HAP ( i. e., NCASI Method IM/ CAN/ WP 99.02). 10 Table 2. Number of Process Units Tested and Number of Non detect Test Runs for Benzene and Acrolein Process unit group recommended for Appendix B testing ( No. nationwide in 2000) 6 Control ( C) or work practice ( WP) under subpart DDDD Acrolein Benzene Detected? No. Process units tested No. BDL runs/

No. total runs Detected? No. Process units tested No. BDL runs/

No. total runs Softwood veneer dryers ( heated zones)

( 303) C/ WP

22 49/ 60

22 61/ 69 Primary tube dryers ( 71) C

11 37/ 40

11 37/ 40 Secondary tube dryers ( 22) C ND 4 12/ 12

4 11/ 12 Rotary strand dryers ( 123) C

18 1/ 33

14 2/ 24 Green rotary dryers ( 84) C

10 13/ 30

9 11/ 30 Hardboard ovens ( 20) C

1 0/ 3 ND 1 3/ 3 Reconstituted wood products presses ( 166) C

15 60/ 73

15 85/ 86 Pressurized refiners ( 43) C

1 0/ 3 ND 1 3/ 3 Press predryers ( 5) C

1 0/ 6 no data Fiberboard mat dryers ( 10) C ( new only)

3 16/ 33

3 27/ 33 Reconstituted wood products board coolers ( 105) C ( new only)

2 0/ 5 ND 3 9/ 9 Dry rotary dryers ( 58) WP

6 8/ 27

6 12/ 27 Hardwood veneer dryers ( heated zones)

( 178) WP ND 4 36/ 36 ND 5 42/ 42 Atmospheric refiners ( 73)

3 6/ 9 ND 3 9/ 9 Conveyor strand dryers, all zones ( 8) C ( zones 1 2) no data no data Veneer redryers ( heated by conventional means) ( unknown) WP no data no data Rotary agricultural fiber dryers ( 3) no data no data Process unit group recommended for Appendix B testing ( No. nationwide in 2000) 6 Control ( C) or work practice ( WP) under subpart DDDD Acrolein Benzene Detected? No. Process units tested No. BDL runs/

No. total runs Detected? No. Process units tested No. BDL runs/

No. total runs 11 Agricultural fiber board presses ( 8) no data no data Paddle type particle dryers ( 2) no data no data Agricultural fiberboard mat dryers ( 1) no data no data Fiberboard mat dryer ( cooling zones) ( 10) no data no data ND = Not detected in any test runs for the process unit group BDL Below the test method detection limit 12 C. Testing only one of multiple dryers Stakeholders suggested that only one of multiple identical dryers at a facility would need to be tested ( e. g., only one of three identical veneer dryers) and that the emissions data from the one dryer tested could be applied to the other identical dryers. This change would decrease the number of emissions tests required without significantly affecting the quality of the emissions determination. To evaluate this request, emissions data gathered at nearly the same time from multiple similar PCWP process units at a plant site were reviewed ( see Attachment 3). The process units were considered to be nearly identical if they were similar in terms of function, firing method, raw materials processed, operating temperature, inlet/ outlet furnish moisture content, and resin type processed. Based on the data in Attachment 3, there appears to be little variation in the test data for similar process units at the same plant site tested at nearly the same time. Most of the data for similar process units varied by a factor of two or less. The greatest variation in the data for similar process units was by a factor of six. Therefore, we recommend that application of test results from one process unit to other similar process units at the same plant site be allowed provided that certain conditions are met. To help evaluate whether process units are " similar," facilities could be required to explain in their test reports or low risk demonstrations how the process units are similar in terms of design, function, heating method, raw materials processed, operating temperature, residence time, resin type processed, and any other parameters that may affect emissions. There are likely to be some slight variations in operating parameters ( e. g., a 5 10% difference in temperature set point, small difference in furnish moisture content between core and face dryers, panel thickness, etc). To account for slight variations in parameters, EPA could require facilities to explain and test the process unit that would be expected to have the greatest emissions ( e. g., the unit with a slightly higher temperature set point, dryer processing higher moisture furnish, press processing thicker panels, etc.) Also, if the process units have different throughput rates, then facilities would need to convert the emission test results to terms of pounds of HAP per unit throughput prior to applying the emissions test data to other similar process units.

The stakeholders also suggested that only one of multiple identical process units from separate facilities within the same company would need to be tested. Unlike for identical process units at the same plant, we have not identified or evaluated any emissions data for identical process units at multiple plants. Due to uncontrollable variations in raw material, the variability in emissions data for identical process units is likely to be greater if the process units are located at different sites than if they are located on the same plant site. For instance, at any given time, identical dryers located on the same plant site generally process wood from the same source ( e. g., same stand of trees, or same sources of planer shavings) that has been handled in the same manner ( e. g., same amount of time in the log yard), but the same may not be true for dryers on multiple sites. Also, if EPA were to allow, for instance, only one of three identical veneer dryers at a plant site to be tested, and then also allow the emissions data for this dryer to be applied to identical dryers at two other sites with three veneer dryers each, then it is possible that the emissions data from this one dryer could be used to represent emissions from eight additional dryers that were not tested. Given that the process units recommended for emissions testing are not hard to test and the potential for increased variability in emissions from plant to plant, we recommend that 13 application of data from one process unit at one plant not be allowed for multiple identical process units at other plants.

D. HAP metals testing for gas fired process units Stakeholders stated that HAP metals emissions testing is not necessary for direct fired process units using only natural gas. The vast majority of PCWP direct fired process units are fired with either wood or natural gas. A small number of PCWP direct fired process units are fired with other fuels ( e. g., residual or distillate oil, propane). Natural gas, or less commonly, propane, is often used as a backup or auxiliary fuel. 14 Although it is possible that HAP metals emissions could originate from combustion in direct wood fired process units, measurable emissions of HAP metals would not be expected from process units fired with natural gas or propane. Therefore, it is reasonable to exclude process units direct fired with only natural gas or propane from the HAP metals testing requirements. However, it is possible that HAP metals could be emitted from process units direct fired using wood, other fuels, or a combination of natural gas ( or propane) and wood or other fuels, and therefore, HAP metals emissions testing is recommended for these units. For clarity, the definitions of " natural gas" ( from the final Oil and Natural Gas Production and Natural Gas Transmission and Storage NESHAP, 64 FR 32610) and " propane" ( from the final Stationary Reciprocating Internal Combustion Engines NESHAP, 69 FR 33474) are recommended for inclusion in Appendix B to subpart DDDD.

IV. Emission Estimation Procedures for Hard to Test Process Units Emission factors for PCWP process units were developed using available emissions test data from nearly 100 test reports collected through EPA's MACT survey, data from EPA's Compilation of Air Pollutant Emission Factors, Volume I: Stationary Point and Area Sources ( commonly referred to as AP 42), and extensive data from the industry sponsored test program performed by NCASI. A separate memorandum discusses in detail how the emission factors were developed. 10 Following development, these emission factors were incorporated into EPA's AP 42, Chapter 10. These emission factors could be used to estimate emissions from most hard totest process units for purposes of completing the PCWP low risk demonstrations. Attachment 4 presents the available emission factors for the Appendix B organic HAP for each process unit group. Other emission estimation methods are needed for hard to test process units for which no emission factors exist. Section IV. A discusses application of emission factors and section IV. B discusses application of other emission estimation procedures for the hard to test process units. Because some types of process units have multiple emission points, we recommend that the estimated emissions be divided evenly across the number of emission points for purposes of the low risk demonstration.

A. Emission factor estimates To apply emission factors, facilities will need the emission factor ( in terms of pounds of HAP per process unit throughput) and the process unit throughput. None of the hard to test 14 process units are equipped with HAP control devices; therefore, control efficiency is not a variable that needs to be considered for the hard to test PCWP process units. 6 We recommend that an amendment to Appendix B to subpart DDDD clearly identify the emission factors that are to be used in low risk demonstrations to streamline completion and review of the low risk demonstrations. Alternatively, if facilities are required to choose their own emission factors ( from AP 42 or elsewhere) for each process unit, then additional time will be required for EPA to verify the emission factor selected for each process unit. It is also recommended that, where multiple emission factors are available for a process unit group, that the maximum emission factor ( i. e., the emission factor resulting from the highest emission test) be used for purposes of the low risk demonstration. Use of the maximum emission factor builds conservatism into the emission estimates to help account for unit to unit variability and ensure protection of public health. Furthermore, the maximum emission factor more closely represents the maximum detected emissions at any process unit and is less likely to have been lowered by use of values equal to ½ of the MDL for non detect measurements. [ For example, if the process unit data set used to develop an average emission factor contains 6 units, 5 of which had no detects during their 3 run tests while the 6th unit had all 3 runs detectable, then the average emission factor would be based on 15 values of ½ MDL and 3 detected values. However, the maximum emission factor would be based on the test where all runs were detected, and therefore, would better represent the maximum detected emissions at any process unit in the group.] As shown in Attachment 5, the maximum emission factor is no more than three times the average emission factor for any of the hard to test process unit groups. Facilities approaching the limits of the lowrisk criteria could be given the option to refine their analysis of HAP emitted by reconfiguring their process unit ( if possible) and conducting emissions testing. Finally, if a HAP was not detected in any emissions test run conducted for a process unit group, then we recommend that emissions for the particular HAP be excluded from the emission estimation requirements because the available emission factors are based on values equal to ½ of the MDL and are not meaningful. Engineering estimates are recommended in some cases where all of the data are non detect, but the available data sets are small and it is reasonable to believe that a particular HAP could be emitted.

Process unit throughput could be based on process unit capacity or actual throughput. Section 11 of Appendix B to subpart DDDD requires facilities to incorporate parameters that defined the affected source as part of the low risk subcategory ( including production rate) as federally enforceable limits in their title V permits. Furthermore, according to section 13( a) of Appendix B to subpart DDDD, facilities must certify with their ongoing title V certification that the basis for their low risk demonstration has not changed ( including process change that would increase HAP emissions such as a production rate increase). Given these requirements, we recommend that facilities be allowed to use the process unit throughput that they wish to incorporate into their title V permit in their emissions estimates for the low risk demonstration ( as opposed to process unit capacity).

The following sections ( 1 through 14) discuss the emission factors available for each of the hard to test process unit groups. With the exception of lumber kilns ( addressed in section 15 IV. B. 1), all of the hard to test process units described below are heated by means other than direct firing ( if heated at all), so estimation of metals emissions is not necessary. [ Note: Table 6 in Section V displays the numeric emission factors selected.]

1. Softwood plywood presses Emissions factors covering the relevant Appendix B HAP ( acetaldehyde, acrolein, formaldehyde, phenol, and benzene) are available for softwood plywood presses. Softwood plywood is not made using MDI resin; therefore, estimation of MDI emissions is not necessary. All of the emission test runs were below the test method detection limit ( BDL) for acrolein and benzene. Since there are no meaningful emission factors for acrolein and benzene, we recommend that these HAP be excluded from the emission estimation requirements. The maximum emission factor for acetaldehyde, formaldehyde, and phenol was selected.

2. Hardwood plywood presses Emissions factors are available for hardwood plywood presses. Hardwood plywood is not made using MDI resin; therefore estimation of MDI emissions is not necessary. All of the emission test runs were BDL for acetaldehyde, acrolein and benzene, and therefore, no meaningful emission factors are available. The maximum emission factors for formaldehyde and phenol were selected.

3. Engineered wood products ( EWP) presses Plants manufacturing engineered wood products such as laminated veneer lumber ( LVL), parallel strand lumber ( PSL), and laminated strand lumber ( LSL) use microwave or RF presses to press billets, which are much thicker than panel products. Glulam plants use clamps to press laminated beams at room temperature. I joist plants do not use presses, but use curing chambers to cure the adhesive in the I joists. 6 The type of resin used by EWP plants varies according to the product manufactured. In some cases, more than one type of resin may be used to manufacture the same product. Phenol formaldehyde ( PF) resins are generally used in manufacture of LVL and PSL. Laminated strand lumber is manufactured with MDI resin. A phenol resorcinolformaldehyde ( PRF) resin is typically used to manufacture glulam and I joists. 11 Emission factors are available for LVL presses. The maximum LVL press emission factors were also applied to PSL presses because no emission factors are available for PSL presses. Both PSL and LVL presses use PF resin to press a veneer based billet. The heating methods and operating temperatures of both types of presses are also similar. Of the Appendix B organic HAP, only acetaldehyde and formaldehyde were detected. MDI is not used to manufacture LVL and PSL.

Emission factors are also available for I joist curing chambers. The emission factors are based on an I joist curing oven used to cure PRF resin. Only formaldehyde was detected at the I joist curing chamber tested. Therefore, the maximum emission factor for formaldehyde was 16 selected for I joist curing chambers. Because no data are available for potential MDI emissions from I joist curing chambers; we recommend that engineering estimates of MDI emissions be generated when MDI is used to produce I joists.

Acrolein, MDI, and formaldehyde emission factors are available for LSL presses. Acrolein was tested, but was not detected in LSL press emissions. Oriented strand board ( OSB) press emission factors were reviewed in order to determine if the other Appendix B organic HAP ( phenol, benzene, and acetaldehyde) could be emitted from LSL presses. The OSB and LSL presses operate at similar temperatures. Benzene was not detected in emissions from other engineered wood products presses or OSB presses, and therefore, benzene is not expected to be emitted from LSL presses. The emission factors for OSB presses using MDI or a combination of PF and MDI resin indicate that acetaldehyde and phenol are emitted in detectable quantities from OSB presses. Therefore, it is reasonable to expect that acetaldehyde and phenol could be emitted from LSL presses. We recommend that engineering estimates be used to estimate acetaldehyde and phenol emissions form LSL presses.

4. Humidifiers Hardboard plants operate humidifiers to stabilize the moisture content of board as it exits from the hardboard ovens. One set of emission factors is available for a hardboard humidifier. The maximum emission factor was selected for the Appendix B organic HAP, all of which were detected during emissions testing. Estimation of MDI emissions is unnecessary because MDI is not used in hardboard manufacture.

5. Blending and forming operations Rotary blenders are used to manufacture particleboard, OSB, and MDF ( at MDF plants with non blow line blend tube dryers). Blenders are used to mix resin, wax, and other additives with dried wood material prior to forming of the loose wood mat. Formers are used in the production of reconstituted wood products. Wet forming is required to manufacture fiberboard, wet/ dry process hardboard, and wet/ wet process hardboard. In the wet forming process, the slurry of water and fiber is metered onto a wire screen where the water drains away. Dry forming is used to manufacture particleboard, MDF, dry/ dry process hardboard, and OSB. In dry forming, material from the blenders is usually transferred to the former via conveyor belt, which may or may not be fully enclosed. Blenders and formers can share emission points to collect material from pneumatic pick up points along the length of blender conveyors and former. Dust collection from the former occurs as reject material is drawn from the sides of the formed wood mat or from hoses on flying cutoff saws. Formers are not enclosed. Available emission factors for blenders and formers are divided according to product type, resin type, and whether blowline blending is used ( for MDF plants). Emission factors are not available for all types of blending and forming operations; however, some of the available emission factors can be applied for different products.

No emission factors specific to particleboard blenders and formers are available. However, emission factors for MDF blenders and formers are applicable to particleboard plants 17 because urea formaldehyde ( UF) resin is used for both particleboard ( conventional and molded) and MDF manufacture. Emission factors are available for an MDF blender, a blender/ former combination, and a former. The blender/ former emission factors are representative of plants that do not perform blowline blending. The former emission factors are representative of plants that perform blowline blending. The blender emission factors are representative of plants that use rotary blenders. Acetaldehyde, acrolein, phenol, and benzene were not detected during any of the tests used to develop these emission factors. Therefore, we recommend that acetaldehyde, acrolein, phenol, and benzene be excluded from the emission estimation requirements. The maximum formaldehyde emission factor from these sets of factors was selected for purposes of estimating emissions from particleboard and MDF blending and forming operations. Particleboard ( e. g., agriboard) and MDF plants sometimes use MDI resin. Because there are no available MDI emission factors for blending and forming operations, we recommend that engineering estimates be used to estimate MDI emissions for those plants that use MDI.

Emission factors are available from one OSB blender and former baghouse system tested at a plant using a combination of PF and MDI resin. The emission factors are based on press throughput. Acetaldehyde, acrolein, phenol, and benzene were not detected at the one blender aspiration system tested. Given that PF resin is used in OSB manufacture, and there are phenol emissions from other PCWP sources ( e. g., MDF and particleboard sanders; PF not used in these products), we believe that phenol emission could reasonably be expected to be emitted from OSB blenders, even though none was detected from the one OSB blender tested. Some facilities manufacture OSB using only PF resin, so the potential for phenol emissions from their blending and forming operations may be even greater than for the one OSB blender tested that used a blend of PF and MDI. Thus, we recommend that engineering estimates of phenol emissions be required for OSB blending and forming operations. The OSB blender/ former emission factors do not include an MDI emission factor. Because there is a possibility that MDI may be emitted from blending and forming operations, we recommend that engineering estimates be required for OSB blending an forming operations involving MDI use.

Wet formers are employed by fiberboard, wet/ wet hardboard, and wet/ dry hardboard plants. Emission factors are available for a fiberboard former ( asphalt additive) and for a wet/ wet hardboard former ( PF resin). The emission factors for the fiberboard former can also be applied to wet/ dry hardboard former because the fiberboard and wet/ dry hardboard processes are similar prior to the pressing step in the wet/ dry hardboard process. The additives used in the wet/ dry hardboard process ( linseed oil, asphalt, and wax) more closely resemble the additives used to produce fiberboard ( alum, starch, asphalt, and wax) than the additives used to produce wet/ wet hardboard ( i. e., PF resin, alum, and wax). Emissions of acetaldehyde and formaldehyde were detected at the fiberboard former tested, so the emission factors resulting from these tests may be used. The other Appendix B HAP were not detected. MDI is not used in producing fiberboard or hardboard. Therefore, emissions estimates for fiberboard and wet/ dry hardboard formers need to be developed for acetaldehyde and formaldehyde only. Emissions of acetaldehyde, formaldehyde, and phenol were detected at the wet/ wet hardboard former tested; therefore, emissions of these three HAP need to be estimated. 18 No emission factors are available to estimate emissions from dry/ dry process hardboard forming operations. Estimation of MDI emissions is not necessary because MDI is not used to manufacture hardboard. Benzene and acrolein emissions have not been detected in tests performed on blending and forming operations used to produce other PCWP. Therefore, benzene and acrolein emissions also are not expected from dry/ dry hardboard formers. We recommend that engineering estimates of acetaldehyde, formaldehyde, and phenol be performed for dry/ dry hardboard formers because these HAP have been detected from forming operations used to produce other PCWP. With one exception, all dry/ dry hardboard plants use blow line blending instead of blenders. Thus, consideration of dry/ dry process hardboard blender emissions is not necessary. One dry/ dry hardboard plant has rotary blenders followed by rotary dryers. This plant was named as part of the PCWP low risk subcategory in the preamble to the final PCWP rule. Should this plant choose to submit a low risk demonstration, it could use engineering estimates of its blender emissions.

6. Sanders and saws Sanders are used to finish all types of PCWP panels. Saws are used throughout PCWP plants to cut logs, cut formed mats before they enter the press, and to trim and cut to size pressed PCWP. Sawdust from saws that cut unpressed mats is collected pneumatically along the former and is included in the former emission points. No HAP test data are available for saws used to cut logs ( e. g., at plywood plants where logs are cut to 8 foot lengths prior to preconditioning in log vats). Sawing of logs is usually performed outside. Appendix B HAP emissions from log sawing are expected to be negligible based on the fact that no Appendix B HAP were detected in log chipping operations.

Appendix B HAP emission factors are available for sanding and sawing operations used in the finishing end of some PCWP plants. Emission factors are available for an: ° MDF sander ° Particleboard sander ° MDF reclaim saw ( emission factors in terms of lb HAP per MSF of reclaimed/ trimmed material; MSF reclaim = MSF from press x 3%) ° Hardwood plywood combined dust baghouse ( trim saw, composer, core saw, dry hog, hammermill, and sander) ° Softwood plywood sander ( 8 drum sander, 1 drum sander, & specialty saw) ° Softwood plywood skinner & equalizer saws ( 3 saws, hog, and sander)

Data were also available for two OSB fuel holding bins that contain wood residue from sanders and saws; these emission factors were lower than the other emission factors available for sanders and saws. Of the Appendix B organic HAP, only acetaldehyde, formaldehyde, and phenol were detected at some of the sander and saw emission points. The configuration of finishing, sanding, and sawing operations emission points at PCWP plants varies widely from plant to plant. The applicability of the available emission factors to other plants is questionable. 19 Panel thickness does not need to be specified for sander throughput since only the panel surface area is sanded. In the absence of more applicable data, the maximum of the sander and saw emission factors for each detected HAP was selected for all PCWP sanding and sawing operations. The acetaldehyde and formaldehyde emission factors for sanders were based on the softwood plywood sander ( 8 drum sander, 1 drum sander, & specialty saw). The phenol emission factor for sanders was based on the particleboard sander. Both the softwood plywood and particleboard sanders sand the top and bottom of the board. The acetaldehyde and formaldehyde emission factors for saws were based on the softwood plywood skinner & equalizer saws ( 3 saws, hog, and sander). Although the softwood plywood sander and saw factors each include both some sander and saw emission points, there is no double counting because the emission factors were derived from tests on separate emission points at one plant ( NCASI mill code 170).

The phenol emission factor for finishing saws was based on the MDF reclaim saw emission factor, which was in terms of pounds per thousand square feet ( lb/ MSF) of material shaved off of the boards by the saw. This material is called " reclaim." At the plant tested, reclaim was measured as the difference in the surface area of the board enterinig and exiting the saw. On average, there was a three percent difference in the board surface area. The MDF reclaim saw phenol emission factor was adjusted by 3% ( 0.19 lb/ MSF x 0.03 = 0.0057 lb/ MSF) to account for the difference in reclaimed ( trimmed) material and press throughput. The MDF saw emission factor is in terms of lb phenol per MSF press throughput. No thickness is provided for the MDF saw emission factor.

No data are available for potential MDI emissions from sanding and sawing operations. We recommend that engineering estimates be used for MDI emissions from sanding and sawing operations.

7. Fiber washers Fiber washers were present at some fiberboard and wet/ dry hardboard plants. Emission factors are available for a fiber washer at a fiberboard plant. The maximum emission factor was selected for acetaldehyde and formaldehyde. Estimation of MDI emissions is unnecessary because MDI is not used in hardboard manufacture. None of the other Appendix B organic HAP were detected during emissions testing.

8. Chippers Log chippers may be used by facilities that begin their manufacturing process with wood chips ( e. g., hardboard, fiberboard, or MDF facilities). Emission factors are available for a hardboard log chipper. None of the relevant Appendix B organic HAP were detected at the log chipper. Therefore, we recommend that no emissions estimates be required for log chipping operations.

Panel trim may also be processed through a chipper. Emission factors are available for a softwood veneer dry trim chipper that processes trimmed veneer from the layup line and for a 20 softwood plywood dry trim chipper that processes dry trim from the panel saws. These emission factors are in terms of pounds of HAP per thousand square feet, 3/ 8" basis, of finished board production. We recommend that the maximum of the veneer trim and panel trim chipper emission factors be applied to all PCWP trim chipper operations. The maximum emission factor was selected for acetaldehyde, formaldehyde, and phenol. Acrolein and benzene were not detected from the chippers, so we recommend that no estimates of acrolein and benzene emissions be developed. Phenol emissions were detected from chipping of dry veneer even though it did not contain phenolic resin, however, no phenol emissions were detected from chipping of the softwood plywood trim, which did contain phenolic resin. Also, MDF and particleboard sanders and an MDF saw exhibited phenol emissions even though phenolic resins are not used in manufacture of MDF. Thus, it appears that phenol emissions may result from some PCWP process equipment even if phenolic resin is not used. Although MDI is not used in veneer or plywood manufacture, it can be used to produce other PCWP. We recommend that engineering estimates of MDI emissions from panel trim chippers be performed by facilities using MDI resin.

9. Log vats Plywood plants typically use log vats to heat logs before they are peeled or sliced into veneer. These log vats use hot water or steam to heat the logs. Hot water vats are often open to the atmosphere, whereas log steaming vats are enclosed. Emission factors are available for log steaming vats. The log steaming vat emission factors are expected to be representative of hot water log vats because both types of vats are used to heat the log cores to the same temperature range. These emission factors are in terms of pounds of HAP per volume of wood ( in MSF 3/ 8") removed from the vat per hour. Of the relevant Appendix B organic HAP, only acetaldehyde was detected in the log vat emissions. Thus, the maximum emission factor for acetaldehyde was selected for log vats.

10. Stand alone digesters Digesting and refining operations are performed at hardboard, fiberboard, and MDF plants. Digesting is the process of steaming or water soaking wood chips so that the chips may be more easily rubbed apart or ground into fibers in the refiners. There are varying methods for digesting and refining wood chips. Some plants operate pressurized refiners that perform both digesting and refining in one process unit while maintaining continuous internal pressure. Other plants operate stand alone digesters that feed into one or more atmospheric refiners. Most standalone digesters and atmospheric refiners have separate emission points ( i. e., each digester and refiner has an emission point). Pressurized refiners have only one emission point at the refiner outlet. Pressurized refiners typically operate as continuous process units ( i. e., with continuous infeed and outfeed of wood material), while stand alone digesters are either batch or continuous units. 6 No emission factors are available for stand alone digesters. However, a set of emission factors is available for a pressurized refiner at a hardboard plant. Therefore the maximum emission factors for the pressurized refiner were selected for acetaldehyde, acrolein, 21 formaldehyde, and phenol. Benzene was not detected from the pressurized refiner, and MDI is not used in these systems. Because pressurized refiners incorporate both the digesting and refining process, it is likely that application of the pressurized refiner emission factors to standalone digesters would reasonably approximate emissions from stand alone digesters.

11. Veneer kilns A small number of softwood and hardwood plywood plants operate veneer kilns instead of veneer dryers. No emission factors are available for veneer kilns. However, emissions for veneer kilns may be estimated by applying emission factors for softwood or hardwood veneer dryers. The maximum available emission factors for softwood veneer dryer heated zones, cooling sections, and fugitive emissions were summed to arrive at an emission factor for softwood veneer kilns. Likewise, the maximum available emission factors for hardwood veneer dryer heated zones and cooling sections were summed to arrive at an emission factor for hardwood veneer kilns. Attachment 6 presents the summation of emission factors for veneer kilns. Since MDI resin is not used in veneer production, estimation of MDI emissions is not necessary. Based on responses to the MACT survey, all of the veneer kilns in the U. S. are indirect fired, so estimation of HAP metals emissions is not necessary.

12. Particleboard press molds and extruders Unlike conventional particleboard plants that operate platen presses to manufacture panels, molded particleboard plants operate either extruders for forming panels or single opening press molds for forming shaped particleboard ( e. g., paper roll cores, pallets). No emission factors are available for particleboard press molds or extruders. However, emission factors are available for conventional particleboard presses that use UF resin. Conventional particleboard presses, press molds, and extruders operate at similar temperatures and process particleboard containing UF resin. The maximum conventional particleboard press emission factors can be used to approximate emissions for extruders and press molds. The emission factors may not be directly applicable to extruders and press molds, but it is the only information available to use in estimating emissions from these sources. It will be necessary for press mold throughput ( which is usually reported in tons instead of MSF 3/ 4") to be converted to volume ( i. e., MSF 3/ 4") using the product density. 11,13,14 13. Fiberboard mat dryer fugitive emissions, softwood veneer dryer fugitive emissions, and veneer dryer cooling zones Emission factors are available for fiberboard mat dryer fugitive emissions. The maximum emission factors may be applied for acetaldehyde and formaldehyde. Estimation of MDI emissions is unnecessary because MDI is not used in fiberboard manufacture. None of the other Appendix B organic HAP were detected during emissions testing.

Similarly, emission factors are available for softwood veneer dryer fugitive emissions. The emission factors for acetaldehyde, formaldehyde, and phenol may be applied. None of the other 22 Appendix B organic HAP were detected during emissions testing. Estimation of MDI emissions is unnecessary.

Emission factors are also available for hardwood and softwood veneer dryer cooling zones. Of the Appendix B organic HAP, acetaldehyde and formaldehyde were detected in the exhaust from hardwood veneer dryer cooling zones. Acetaldehyde, formaldehyde, and phenol were detected in the exhaust from softwood veneer dryer cooling zones. Estimation of HAP metals and MDI emissions is unnecessary from veneer dryer cooling zones because the cooling zones circulate ambient air over the hot veneer ( i. e., no combustion exhaust is involved) and MDI is not used to manufacture veneer.

14. Radio frequency veneer redryers Acetaldehyde and formaldehyde have been detected from RF veneer redryers. None of the other Appendix B organic HAP have been detected, and MDI is not applied to veneer. Emission factors are available to use in estimating acetaldehyde and formaldehyde emissions from RF veneer redryers.

B. Other Emission Estimation Techniques There are some common types of hard to test PCWP processing equipment for which no emission factors are available, including resin storage tanks, lumber kilns, and wastewater/ process water operations. This section describes emission estimation procedures that may be used for PCWP processes that currently have no applicable emission factors.

1. Lumber kilns Lumber kilns are batch units. Lumber is loaded into the kiln, the kiln runs through the drying cycle, and the dried lumber is removed from the kiln when the drying cycle is complete. Softwood lumber kiln drying cycles typically last around 24 hours, while hardwood kiln drying cycles can last from several days to weeks. The emissions profile from lumber kilns depends on kiln drying time, moisture content of the wood, kiln temperature, and air flow through the kiln. The amount and direction of air that is vented from the kiln changes in response to kiln process parameters such as relative humidity, dry bulb temperature, and wet bulb temperature. Lumber kilns have multiple vents, which alternate in function. During any given time, one set of vents allows moisture to exhaust from the kiln while the other set of vents brings in dry air. After some time, the direction of air circulation within the kiln is changed, and the kiln vents exchange functions. Because of these changes in air flow patterns, lumber kiln emission streams vary in flow rate, concentration, and mass emission rate throughout the kiln drying cycle. In addition to emissions from lumber kiln vents, considerable amounts of fugitive emissions may be emitted from lumber kilns through crevices in the kiln wall and around doors.

It is difficult to measure emissions from lumber kilns due to the kiln air flow design and fugitive emissions. Therefore, little emissions test data is available for use in developing HAP 23 emission factors for lumber kilns. Methods for quantifying lumber kiln flow rates vary from test to test. Most of the emissions test data that is available contains calculated flow rates or other assumptions that bring the validity of the data into question. Most of the available emissions data for lumber kilns is for total hydrocarbon ( THC) emissions from softwood lumber kilns. A few tests have been conducted on both small and large scale lumber kilns to determine emissions of HAP ( generally formaldehyde and methanol) from softwood lumber kilns.

Emission factors for lumber kilns were not included in EPA's emission factor data base developed for MACT. 10 However, a discussion of available data ( as of June 2000) for lumber kilns was presented in Appendix D of the baseline emission memo. 11 Additional literature was reviewed, including NCASI Technical Bulletin ( TB) 845 and two technical papers. 15,16,17 For purposes of conservatively estimating lumber kilns emissions, the maximum emission factors for the Appendix B HAP presented in the literature reviewed may be used. Table 3 lists each emission factor, the process unit tested, and the reference. No HAP metals data are available for direct fired lumber kilns. We recommend that engineering estimates of HAP metals emission be developed for direct fired lumber kilns.

Another approach to determining emissions from lumber kilns may be through use of small scale kilns. While emissions testing of full scale lumber kilns has proven to be very difficult, studies have shown that testing of small scale lumber kilns can be used to reasonably approximate emissions from full scale lumber kilns if representative lumber samples are dried and the venting characteristics of the small scale kiln mimic those of the full scale kiln. 15,18 Several U. S. universities and private laboratories operate small scale kilns. To approximate emissions from full scale kilns, a representative sample of lumber is taken from the full scale kiln facility, packaged to prevent moisture loss, and shipped to the location of the small scale kiln where the full scale kiln's drying cycle ( e. g., time and temperatures) is mirrored during emissions testing. Small scale kilns are designed for more accurate air flow measurement and are less costly to test. In order to allow a small scale kiln approach, it may be necessary to develop regulatory text ( or incorporate by reference appropriate material) to provide standard procedures for selecting a representative small scale kiln, submitting lumber samples, and conducting small scale kiln emissions testing. A separate memorandum provides examples of factors that need to be considered when developing a small scale kiln emission testing program. 19 24 Table 3. Maximum available lumber kiln emission factors.

Appendix B HAP Emission factor lb/ MBF Kiln tested Test method Reference Acetaldehyde 0.065 Oregon State University ( OSU) small scale indirect fired kiln, southern pine NICM NCASI TB 845 Acrolein 0.009 OSU small scale indirect fired kiln, southern pine NICM NCASI TB 845 Formaldehyde 0.034 Direct fired softwood kiln ( fullscale TO 5 NCASI data base Phenol 0.010 Direct fired softwood kiln ( fullscale TO 8 NCASI data base Benzene not detected  North Carolina State University, indirect fired, southern pine  Indirect fired, southern pine, fullscale kiln  OSU small scale indirect fired kiln, southern pine NICM NCASI TB 845 MDI NA ( MDI not used to produce kilndried lumber)

HAP metals for direct fired kilns no data OSU= Oregon State University, NCSU = North Carolina State University NCASI  National Council for Air and Stream Improvement, TB = Technical Bulletin NICM = NCASI Impinger/ Cannister Method MDI = methylene diphenyl diisocyanate 2. Resin tanks Resin storage tanks are located at most PCWP plants. The tanks contain UF, PF, MDI, or other types of resins or additives ( e. g., wax, scavenger). These resins exhibit low vapor pressures and low volatility. Specific information on storage tanks was collected through EPA's general MACT survey, but was not requested for hardwood plywood or engineered wood products plants. The MACT survey also requested information on potential HAP emissions from resin tanks. Only about 35 percent of survey respondents provided information on HAP emissions from resin tanks, and these estimates varied by four orders of magnitude ( e. g., 1.3E 5 to 7.6E 1 tpy for formaldehyde). The maximum emissions reported for any single tank are summarized in Table 4. The tank emission estimates reported in the survey responses were likely generated using TANKS software. 14 One conservative approach to estimating resin tank emissions for purposes of the low risk demonstration would be to multiply the maximum emission estimates from Table 4 below by the 25 number of tanks at the facility. This approach may be ideal for facilities who do not have the necessary data readily available to use TANKS software. Application of the values in Table 4 would depend on tank content ( e. g., MDI would only be estimated for MDI containing tanks, formaldehyde for UF and PF tanks, and phenol for PF tanks). Facilities who wish to refine their analysis of tank emissions could obtain the necessary inputs for the TANKS software and run the software to generate more site specific estimates. The TANKS software may be obtained from EPA's Technology Transfer Network ( ttn).

Table 4. Worst case Appendix B HAP emissions from resin storage tanks Pollutant Emissionsa ( tpy per tank) Emissionsb ( lb/ hr per tank) c Formaldehyde 0.76 0.19 Phenol 0.70 0.18 MDI 0.005 0.0013 a Maximum reported uncontrolled emissions for each HAP from any individual storage tank. 14 b Emissions ( tpy) divided by typical plant operating hours ( 8,000 hr/ yr). 11 b lb/ hr = pounds per hour 3. Wastewater/ process water operations Wastewater operations ( e. g., lagoons, clarifiers, settling ponds, tanks, etc.) are used for handling process waters or wastewaters, which may contain traces of HAP. Water is used for many purposes at PCWP plants, including hardboard process operations, equipment washing ( e. g., the glue line, blender, dryers, regenerative thermal oxidizers, etc.), and in control devices ( i. e., wet ESP's and scrubbers). After use, the water is generally conveyed to a holding pond or tank where some of the water evaporates, and some may be recirculated for reuse in the process or a control device. Some water may also be discharged to a wastewater treatment system, including onsite land application via spraying. An attempt was made to gather information on potential emissions from PCWP water operations with the MACT survey. However, HAP concentration data were provided for only 23 of the 241 wastewater operations for which flow rates were provided. It is not known how the potential emissions from PCWP water operations could vary from facility to facility because there are various sources of water, and there is a wide range of water flow rates and handling methods. Although potential HAP emissions from PCWP water operations are believed to be low, the available data do not provide sufficient information for specifying an emission factor that could be applied to all PCWP facilities. More site specific information is needed for the low risk demonstration. Air emissions of HAP metals from PCWP wastewater operations are not expected given the low volatility of metals at typical wastewater temperatures.

The following subsections ( a through d) discuss three methods for estimating emissions wastewater/ process water operations and other considerations. All three of the methods for estimating emissions necessitate sampling of the wastewater/ process water to determine the concentration of Appendix B HAP. The worst case Appendix B HAP concentration in the 26 wastewater/ process water is of interest for purposes of the low risk demonstration. Potential methods for analyzing water samples are listed in Attachment 7. Potential regulatory language that specifies procedures for identifying sample locations, collecting and handling samples, using non detect measurements, and validating methods that differ from approved EPA methods is also presented in Attachment 7. As for air samples, we recommend that the concentration of HAP in the water sample be assumed to be zero if all of the water samples in a test result in a non detect reading, and the MDL is less than or equal to 1 ppmw. Otherwise, we recommend that nondetect data be treated as one half of the MDL. This would deter facilities from attempting to measure water concentrations using methods or equipment with low sensitivity in order to purposely obtain non detect measurements, and would also prevent facilities from having to assume the MDL for HAP that are not present ( or are present in very low concentrations) in water stream.

a. Option 1: WATER9 modeling One method for estimating wastewater/ process water emissions would be through the application of EPA's WATER9 model ( available at http:// www. epa. gov/ ttn/ chief/ software/ index. html). WATER9 uses analytical expressions and a data base of organic compounds to provide separate emission estimates for each individual compound that is identified as a constituent of the wastewater/ process water. The emission estimates are based upon the properties of the compound and its concentration. To obtain these emission estimates, the facility would have to collect and analyze water samples from inlet streams to provide their concentrations of Appendix B HAP. WATER9 may be used to estimate air emissions from common wastewater management and treatment units including: drains, sumps, weirs, open drains, j traps, manhole covers, trenches, buried conduits ( sewers), junction boxes, pump stations, clarifiers, trickling filters, aerated impoundments, quiescent impoundments, cooling towers, activated sludge units, storage tanks, wastewater separators, and settling ponds. Impoundments ( e. g., settling ponds) and wastewater storage tanks are most commonly found at PCWP facilities.

b. Option 2: Mass transfer calculations ( similar to those in WATER9)

Another approach for estimating HAP emissions from water operations would be to have the rule specify both the appropriate mass transfer relationships to use and the specific water operations for which emissions must be estimated. If the collection and conveyance system consists of hard piping, then emissions only need to be estimated for open water tanks and ponds, including those that are part of zero discharge systems as well as those that precede discharge to a treatment unit. The applicable equations to estimate emission from open ponds and tanks are presented in Attachment 8 and summarized below. In Appendix B to subpart DDDD, the ponds and tanks could be classified as " water management units" with the following definition:

" water management unit means each uncovered tank or pond that receives water from process operations including but not limited to hardboard operations, washing of process or control equipment, or as discharge from a wet control device. The tank or pond may be a final disposal unit, an equalization basin or holding unit in a once through system 27 E KACL = ( Eq. 1)

1 1 K k RT k H L G = + ( Eq. 2) prior to wastewater treatment, or a holding unit for water that is recirculated for process uses or in a control device. A water management unit is a process unit."

The appropriate mass transfer relationships for estimating emissions from water management units are the same as those used in the WATER9 model. The basic relationship describing mass transfer of a volatile constituent from an open liquid surface to the air is:

where: E = air emissions from the liquid surface, g/ s K = overall mass transfer coefficient, m/ s A = liquid surface area, m2 C L = concentration of individual HAP in the water, g/ m3 The overall mass transfer coefficient ( K) is estimated from a two phase resistance model that is based on the liquid phase mass transfer coefficient ( k L in m/ s), the gas phase mass transfer coefficient ( k G in m/ s), and Henry's law constant. The two resistances act in series, and the overall resistance is expressed as:

where:

K = overall mass transfer coefficient, m/ s k L = liquid phase mass transfer coefficient, m/ s k G = gas phase mass transfer coefficient, m/ s R = universal gas constant ( 8.21 x 10 5 atm° m3/ gmol° K) T = temperature of the air, K H = Henry's law constant for the HAP, atm° m3/ gmol Several empirical models that are used in WATER9 to estimate the gas phase and liquidphase mass transfer coefficients are presented in Attachment 8.20 An identical model is codified in Appendix C to 40 CFR Part 63, in Forms VII and VIII. The models are functions of numerous pond or tank characteristics and properties of the HAP that are present in the water. The appropriate model also depends on whether the water in the pond or tank is agitated, the wind speed, and the fetch to depth ratio for the pond or tank ( fetch is the linear distance across the liquid surface in the direction of wind flow). This discussion assumes that biological activity in the pond or tank is negligible. This is a worst case assumption because a pond or tank in which biodegradation is occurring will have lower emissions ( although it may not make much difference 28 over the short, one hour, periods that are of interest for the risk demonstration). For an aerated pond or tank, note that separate overall mass transfer coefficients must be developed using Equation 2 for both the aerated and quiescent zones in the tank or pond. These overall mass transfer coefficients for each zone are calculated using the appropriate equations for the gas phase and liquid phase mass transfer coefficients provided in Attachment 8. A single overall coefficient for use in Equation 1 is calculated by determining a weighted average of the overall coefficients for the two zones based on the relative surface areas of the two zones in the tank or pond. Additional information regarding the development of these models can be found in the companion document for WATER9.20 Attachment 8 provides an example calculation based on the equations presented in Attachment 8 ( which are essentially identical to those contained in Forms VII and VIII of Appendix C to 40 CFR Part 63).

Both the WATER9 modeling approach discussed in subsection " a" above, and the mass transfer calculation approach discussed in this subsection require the Henry's law constant ( H) and diffusivities in water ( D w) and air ( D a) of each HAP at the appropriate temperature. WATER9 contains a database with the values for these parameters at 25

C, and it automatically calculates the correct values to use when the user specifies a different temperature. The same data and adjustment procedures can be used in the equations that are presented in Attachment 8, or the appropriate values can be obtained from chemical reference manuals. Attachment 8 tabulates the WATER9 values for H, D w, and D a at 25

C for each of the six organic HAP in Appendix B to subpart DDDD. Attachment 8 also presents the equations that WATER9 uses to make the temperature corrections. Other variables in the equations are parameters that must be determined for each plant on a site specific basis. The values for these parameters also would need to be established at the " worst case" levels that result in the maximum hourly emissions for the water management unit. Other site specific parameters needed in the calculations include the air and water temperatures, wind speed, dimensions of the pond or tank, power to aerators, impeller diameter, and impeller rotational speed.

c. Option 3: Assume evaporation and discharge rate are equivalent A third approach for estimating HAP emissions from water operations would be to assume that the HAP evaporation rate equals the rate at which it is discharged to the water management unit. Under this approach, the flow rates and HAP concentrations would need to be determined for all of the streams that discharge to the water management unit. The worst case would be if all of the streams could discharge simultaneously. If this is not physically possible due to some type of processing or water collection system constraint, then the worst case would be for the combination of streams with the highest hourly discharge rate of each HAP that could realistically occur. If the collection system is not hard piped, then the concentration measurements should be made at the inlet to the collection system; if the collection system is hard piped, then the samples could be taken anywhere in the collection system. This approach would also be applicable for estimating emissions from the spraying associated with treatment by land application ( i. e., the worst case estimate would be to determine the maximum hourly HAP load to the spray head( s), and assume all of it volatilizes). 29 d. Other considerations MDI. It is possible that MDI emissions from water management units are so low that the risk from such emissions will be infinitesimal at all facilities in the industry. As shown in Attachment 8, the Henry's law constant and diffusivities in air and water are all extremely low. In addition, the MDI concentration in the water management unit is likely to be low because there may be few ways in which MDI would be expected to enter the water stream. Potential sources of MDI in water streams could include MDI blender wash water or wash water from RTO's on presses that process board containing MDI resin ( although it is likely that most of the MDI is combusted rather than residing in the RTO). As a result, it might be productive to conduct a preliminary risk assessment using conservative assumptions to determine the maximum risk that might be expected for MDI emissions from water management units. However, in the absence of information on potential MDI concentrations in water streams and a study documenting that MDI is likely to pose no risk from any facility, each facility with MDI in water streams should include MDI emissions from water management units in their low risk determinations.

Sampling location. If water streams are not hard piped from the process discharge point to the pond or tank, then depending on HAP concentrations and system characteristics, emissions from the collection and conveyance system could be significant relative to the emissions from the pond or tank. This is especially true for more volatile HAP such as acetaldehyde, acrolein, and benzene, all of which have much higher Henry's law constants than formaldehyde, phenol, and MDI. Thus, for acetaldehyde, acrolein, and benzene, option 1 or 3 should be used instead of option 2 to estimate emissions from both the collection system and the holding pond or tank unless the collection system is constructed of hard piping. If the only Appendix B HAP in the pond or tank are formaldehyde, phenol, and/ or MDI, then emissions from the collection system can be ignored, and only the emissions from the holding pond or tank need to be estimated using any of the options.

As mentioned previously, the worst case Appendix B HAP concentration in the wastewater/ process water is of interest for purposes of the low risk demonstration. One way to determine the worst case HAP concentration for option 2 would be to collect and analyze water samples from all of the inlet streams and very conservatively assume that the maximum concentration in any individual inlet stream represents the maximum concentration in the wastewater/ process water operation. Because this approach would clearly overstate the maximum emissions, Appendix B to Subpart DDDD could also allow facilities to develop their own site specific approach to selecting appropriate sampling locations. Facilities selecting their own sampling locations would need to identify the number of locations at which samples would be collected, indicate what fraction of the surface area is represented by each sample, and provide supporting rationale. Part of the supporting rationale would include a description of the design and operation of the water management unit including, but not limited to, the dimensions of the unit, inlet and outlet locations, and mixing methods. Potential regulatory language regarding selection of sampling location is included in Attachment 7. 30 V. Summary of Recommended Procedures for Determining HAP Emissions In section III. A. 2, we recommended that emissions from each type of process unit ( that could potentially emit any of the HAP listed in Appendix B) be considered in the low risk demonstration through emissions testing or estimation, as appropriate, depending of the feasibility of emission testing. We recommended emissions testing for process units that are feasible to test. Emissions estimation is recommended for process units that are hard to test ( i. e., generally are not configured and cannot readily be configured from emissions testing). Table 5 presents a summary of process units according to feasibility of emissions testing and recommended approach to determining emissions for purposes of the low risk demonstration.

Section III. B addressed issues related to benzene and acrolein emission testing. The EPA has decided that it is appropriate to allow use of NCASI Method IM/ CAN/ WP 99.02 and EPA Method 18 for measurement of benzene. We recommended that benzene and acrolein testing be required for all of the process units that must be tested for the other Appendix B organic HAP ( i. e., process units that can feasibly be tested) for the following reasons: ( 1) the available data do not allow one to conclude that benzene and acrolein would not be emitted for a given process unit type; ( 2) the process units are not hard to test; and ( 3) testing for benzene and acrolein would not substantially increase the overall testing burden.

In section III. C, we recommended that application of test results from one process unit to other similar process units at the same plant site be allowed provided that facilities explain in their test reports or low risk demonstrations how the process units are similar in terms of design, function, heating method, raw materials processed, operating temperature, residence time, resin type processed, and any other parameters that may affect emissions. To account for slight variations in parameters, EPA could require facilities to explain and test the process unit that would be expected to exhibit greater emissions. We also recommended that application of data from one process unit at one plant not be allowed for multiple identical process units at other plants.

In section III. D, we recommended that process units direct fired with only natural gas or propane be excluded from the HAP metals testing requirements for direct fired units. However, we recommended that EPA continue to require HAP metals testing for process units direct fired using wood, other fuels, or a combination of natural gas ( or propane) and wood or other fuels.

In section IV, we discussed emission estimation procedures that may be used to estimate emissions from hard to test process units. In section IV. A, we recommended that the estimated emissions be divided evenly across the number of emission points for purposes of the low risk demonstration. Emission factor estimates were recommended for process units with available emission factors. The maximum available emission factor was selected for each process unit and pollutant combination. With a few exceptions, we recommended that emissions of a particular HAP be excluded from the low risk demonstration for hard to test process units if all of the available emission factors were based on values ½ of the MDL ( i. e., if all of the test data for a HAP was non detect for a certain process unit group). Engineering estimates were recommended 31 if no emission factors are available for HAP that could reasonably be expected to be emitted from a given process unit. In section IV. B, emission techniques were specified for hard to test process units with no available emission factors ( i. e., lumber kilns, resin tanks, and wastewater/ process water operations).

In summary, Table 6 lists each process unit and Appendix B pollutant and presents the procedures recommended in this memorandum for determining Appendix B HAP emissions from each type of PCWP process unit for purposes of the low risk demonstration. A table similar to Table 6 could be incorporated into Appendix B to subpart DDDD through an amendment. 32 Table 5. Overview of Appendix B requirements for determining emissions from PCWP process units Type of process unit Feasibility of emissions testing Appendix B requirement for emissions determination Agricultural fiber board presses Agricultural fiberboard mat dryers Atmospheric refiners Conveyor strand dryers ( all zones) Dry rotary dryers Fiberboard mat dryers ( heated and cooling zones) Green rotary dryers Hardboard ovens Hardwood veneer dryers ( heated zones) Paddle type particle dryers Press predryers Pressurized refiners Primary tube dryers Reconstituted wood product presses Reconstituted wood product board coolers Rotary strand dryers Rotary agricultural fiber dryers Secondary tube dryers Softwood veneer dryers ( heated zones) Veneer redryers ( heated by conventional means) Feasible to test Emissions testing is required for the following organic HAP: acetaldehyde, acrolein, formaldehyde, phenol, and benzene. In addition, MDI testing is required for process units processing material containing MDI resin. Testing for HAP metals ( arsenic, beryllium, cadmium, chromium, lead, manganese, and nickel) is required for direct fired process units ( except for units directfired with only natural gas or propane).

Blending and forming operations Engineered wood products presses Fiber washers Fiberboard mat dryers ( fugitive emissions) Finishing sanders Finishing saws Hardwood plywood presses Hardwood veneer dryers ( cooling zones) Humidifiers Log vats Lumber kilns Panel trim chippers Particleboard press molds Particleboard extruders Radio frequency veneer redryers Resin tanks Softwood veneer dryers ( cooling zones) Softwood plywood presses Stand alone digesters Veneer kilns Wastewater/ process water operations Hard to test Emissions estimates according to method specified in Appendix B Log chipping Miscellaneous coating operations Softwood veneer dryer ( fugitive emissions) Hard to test Not applicable ( Appendix B HAP not emitted)

Other ancillary processes that emit Appendix B HAP emissions Hard to test Emissions estimates ( engineering estimate)

Note: Different terms for some of the process unit types may be incorporated into Appendix B. For example, engineered wood products presses had to be subdivided for application of emission factors. Attachment 2 supplies sugested process unit definitions. 33 Table 6. Summary of recommended testing or emissions estimation procedures for process units to be included in Appendix B to subpart DDDD.

Process unit type Subpart DDDD control ( C) or work practice ( WP) Acetaldehyde Acrolein Formaldehyde Phenol Benzene MDI HAP metals from direct fired process unitsb Agricultural fiber board presses none test test test test test test if board contains MDI resin NA Agricultural fiberboard mat dryers none test test test test test NA test Atmospheric refiners none test test test test test NA NA Blending and forming operations  OSB none NA NA 0.0036 lb/ MSF 3/ 8" press throughput engineering estimate NA engineering estimate if MDI resin used NA Blending and forming operations  particleboard and MDF none NA NA 0.060 lb/ ODT NA NA engineering estimate if MDI resin used NA Conveyor strand dryers C test test test test test NA NA Dry forming

hardboard none engineering estimate NA engineering estimate engineering estimate NA NA NA Dry rotary dryers WP test test test test test NA test Fiber washers none 0.015 lb/ ODT NA 0.0026 lb/ ODT NA NA NA NA Fiberboard mat dryer ( fugitive emissions) none 0.0055 lb/ MSF ½ " NA 0.031 lb/ MSF ½ " NA NA NA NA Table 6, continued Process unit type Subpart DDDD control ( C) or work practice ( WP) Acetaldehyde Acrolein Formaldehyde Phenol Benzene MDI HAP metals from direct fired process unitsb 34 Fiberboard mat dryer ( heated zones) C ( new) test test test test test NA test Finishing saws none 0.00092 lb/ MSF 3/ 8" NA 0.00034 lb/ MSF 3/ 8" 0.0057 lb/ MSF NA engineering estimate if MDI resin used NA Finishing sanders none 0.0028 lb/ MSF 3/ 8" NA 0.0042 lb/ MSF 0.015 lb/ MSF NA engineering estimate if MDI resin used NA Green rotary dryers C test test test test test NA test Hardboard ovens C test test test test test NA test Hardwood veneer dryers ( heated zones) WP test test test test test NA test Hardwood veneer dryer, cooling zones none 0.058 lb/ MSF 3/ 8" NA 0.013 lb/ MSF 3/ 8" NA NA NA NA Hardwood plywood presses none NA NA 0.0088 lb/ MSF 3/ 8" 0.016 lb/ MSF 3/ 8" NA NA NA Hardwood veneer kilns none 0.067 lb/ MSF 3/ 8" NA 0.016 lb/ MSF 3/ 8" 0.0053 lb/ MSF 3/ 8" NA NA NA Humidifiers none 0.0018 lb/ MSF 1/ 8" 0.0087 lb/ MSF 1/ 8" 0.0010 lb/ MSF 1/ 8" 0.00057 lb/ MSF 1/ 8" 0.0000062 lb/ MSF 1/ 8" NA NA Table 6, continued Process unit type Subpart DDDD control ( C) or work practice ( WP) Acetaldehyde Acrolein Formaldehyde Phenol Benzene MDI HAP metals from direct fired process unitsb 35 I joist curing chambers none NA NA 0.00018 lb/ MLF NA NA engineering estimate if MDI resin used NA Log steaming vats none 0.0047 lb/ MSF 3/ 8" removed from vat per hour NA NA NA NA NA NA LSL presses none engineering estimate NA 0.029 lb/ 1000 ft3 engineering estimate NA 0.18 lb/ 1000 ft3 NA Lumber kilns none 0.065 lb/ MBF 0.009 lb/ MBF 0.034 lb/ MBF 0.010 lb/ MBF NA NA Engineering estimate LVL presses none 0.29 lb/ 1000 ft3 NA 0.79 lb/ 1000 ft3 NA NA NA NA Paddle type particleboard dryers none test test test test test NA test Panel trim chippers none 0.00081 lb/ MSF 3/ 8"

finished board production NA 0.00034 lb/ MSF 3/ 8"

finished board production 0.0019 lb/ MSF 3/ 8" finished board production NA NA NA Particleboard press molds and particleboard extruders none 0.034 lb/ MSF 3/ 4" 0.0087 lb/ MSF 3/ 4" 0.64 lb/ MSF 3/ 4" 0.024 lb/ MSF 3/ 4" 0.0073 lb/ MSF 3/ 4" NA NA Table 6, continued Process unit type Subpart DDDD control ( C) or work practice ( WP) Acetaldehyde Acrolein Formaldehyde Phenol Benzene MDI HAP metals from direct fired process unitsb 36 Press predryers C test test test test test NA test Pressurized refiners C test test test test test NA NA Primary tube dryers C test test test test test test if processing furnish with MDI resin added prior to drying test Radio frequency veneer redryers none 0.0029 lb/ MSF 3/ 8" NA 0.00065 lb/ MSF 3/ 8" NA NA NA NA Reconstituted wood products presses C test test test test test test if board contains MDI resin NA Reconstituted wood product board coolers C ( new) test test test test test test if board contains MDI resin NA Resin storage tanks none NA NA 0.19 lb/ hr per tank for tanks with resin containing formaldehyde OR model using TANKS softwarea 0.18 lb/ hr per tank for tanks with resin containing phenol OR model using TANKS softwarea NA 0.0013 lb/ hr per tank for tanks with MDI resin OR model using TANKS softwarea NA Table 6, continued Process unit type Subpart DDDD control ( C) or work practice ( WP) Acetaldehyde Acrolein Formaldehyde Phenol Benzene MDI HAP metals from direct fired process unitsb 37 Rotary strand dryers C test test test test test NA test Rotary agricultural fiber dryers none test test test test test NA test Secondary tube dryers C test test test test test test if processing furnish with MDI resin added prior to drying test Softwood plywood presses none 0.012 lb/ MSF 3/ 8" NA 0.0054 lb/ MSF 3/ 8" 0.0022 lb/ MSF 3/ 8" NA NA NA Softwood veneer dryers ( heated zones) C/ WP test test test test test NA test Softwood veneer dryers ( cooling zones) none 0.012 lb/ MSF 3/ 8" NA 0.0028 lb/ MSF 3/ 8" 0.011 lb/ MSF 3/ 8" NA NA NA Softwood veneer kilns none 0.097 lb/ MSF 3/ 8" 0.012 lb/ MSF 3/ 8" 0.10 lb/ MSF 3/ 8" 0.020 lb/ MSF 3/ 8" 0.0078 lb/ MSF 3/ 8" NA NA Stand alone digesters none 0.030 lb/ ODT 0.0024 lb/ ODT 0.0045 lb/ ODT 0.0012 lb/ ODT NA NA NA Veneer redryers ( heated by conventional means) WP test test test test test NA test Table 6, continued Process unit type Subpart DDDD control ( C) or work practice ( WP) Acetaldehyde Acrolein Formaldehyde Phenol Benzene MDI HAP metals from direct fired process unitsb 38 Wastewater/ process water operations none engineering estimate ( such as WATER9a or other method) engineering estimate ( such as WATER9a or other method) engineering estimate ( such as WATER9a or other method) engineering estimate ( such as WATER9a or other method) engineering estimate ( such as WATER9a or other method) engineering estimate ( such as WATER9a or other method) if MDI resin used NA Wet forming

fiberboard and hardboard ( without PF resin) none 0.0075 lb/ MSF ½ " NA 0.0036 lb/ MSF ½ " NA NA NA NA Wet forming

hardboard ( PF resin) none 0.0067 lb/ ODT NA 0.00039 lb/ ODT 0.00075 lb/ ODT NA NA NA Miscellaneous coating operations, log chipping, and softwood veneer dryer fugitive emissions none NA NA NA NA NA NA NA Other ancillary processes ( not listed elsewhere in this table)

that may emit HAP listed in this table none engineering estimate engineering estimate engineering estimate engineering estimate engineering estimate engineering estimate engineering estimate test: Emissions testing must be conducted for the process unit and pollutant according to the test methods specified in Table 2B to Appendix B to subpart DDDD.

NA: Not applicable. No emission estimates or emissions testing is required for purposes of the low risk demonstration. Table 6, continued 39 lb/ MSF: Pounds of HAP per thousand square feet of board of the inches thickness specified ( e. g., lb/ MSF 3/ 4 = pounds of HAP per thousand square feet of 3/ 4 inch board). See equation in § 63.2262( j) of subpart DDDD to convert from one thickness basis to another.

lb/ ODT: Pounds of HAP per oven dried ton of wood material a TANKS and WATER9 software is available at http:// www. epa. gov/ ttn/ chief/ software/ index. html b Excludes direct fired process units fired with only natural gas or propane. 40 References:

1. National Emission Standards for Hazardous Air Pollutants: Plywood and Composite Wood Products; Effluent Limitations Guidelines and Standards for the Timber Products Point Source Category; List of Hazardous Air Pollutants, Lesser Quantity Designations, Source Category List. 69 FR 45944. July 30, 2004.

2. T. Hunt, AF& PA, to M. Kissell, K. Hustvedt, S. Jenkins, and D. Guinnup, EPA/ ESD. June 3, 2004. E mail transmitting white paper containing the industry's recommendations regarding process unit testing and alternatives to demonstrate eligibility for the low risk subcategory.

3. Memorandum from K. Hanks, RTI, to M. Kissell, EPA/ ESD. April 27, 2004. Meeting Minutes for the March 29, 2004 Conference Call Between the U. S. Environmental Protection Agency ( EPA), the American Forest and Paper Association ( AF& PA), and Representatives of the PCWP Industry.

4. Memorandum from K. Hanks, RTI, to M. Kissell, EPA/ ESD. April 12, 2004. Meeting Minutes for the April 1, 2004 Conference Call Between the U. S. Environmental Protection Agency ( EPA), the American Forest and Paper Association ( AF& PA), and Representatives of the PCWP Industry 5. T. Hunt, AF& PA, to M. Kissell, K. Hustvedt, and D. Guinnup, EPA/ ESD. February 19, 2004. E mail transmitting white paper containing industry's suggestions regarding testing of process units for benzene and acrolein process when demonstrating eligibility for the low risk subcategory.

6. Memorandum from K. Hanks, B. Nicholson, and K. Parrish, RTI, to M. Kissell, EPA/ ESD. December 15, 2003. Determination of MACT floors and MACT for the Final Plywood and Composite Wood Products Industry NESHAP.

7. U. S. EPA, National Emission Standards for Hazardous Air Pollutants for Plywood and Composite Wood Products, Background Information for Final Standard, Summary of Public Comments and Responses. February 2004.

8. Memorandum from K. Hanks, RTI, to M. Kissell, EPA/ ESD. November 7, 2003. Estimates of Ancillary Plywood and Composite Wood Products Process Emissions for Use in Risk Modeling.

9. National Council for Air and Stream Improvement. An Evaluation of Credit Generating Emission Sources for Use in the Emissions Averaging Compliance Option Under the Wood Products NESHAP. Technical Bulletin No. 869. December 2003. 41 10. Memorandum from D. Bullock and K. Hanks, MRI, to M. Kissell, EPA/ ESD. April 27, 2000. Documentation of Emission Factor Development for the Plywood and Composite Wood Products Manufacturing NESHAP.

11. Memorandum from K. Hanks and D. Bullock, MRI, to M. Kissell, EPA/ ESD. June 9, 2000. Baseline Emission Estimates for the Plywood and Composite Wood Products Industry.

12. D. Word to G. McAlister, EPA/ ESD. June 22, 2004. Email transmitting information related to quality assurance data benzene measured using NCASI IM/ CAN/ WP 99.02.

13. U. S. EPA. Background Information Document for Plywood and Composite Wood Products NESHAP. Office of Air Quality Planning and Standards, Research Triangle Park, NC 27711, EPA 453/ R 01 004, September, 2000.

14. Memorandum from D. Bullock, K. Hanks, and B. Nicholson, MRI to M. Kissell, EPA/ ESD. April 28, 2000. Summary of Responses to the 1998 EPA Information Collection Request ( MACT Survey)  General Survey.

15. National Council for Air and Stream Improvement. A Comparative Study of VOC Emissions from Small scale and Full scale Lumber Kilns Drying Southern Pine. Technical Bulletin No. 845. May 2002.

16. Milota, M., Oregon State University. Drying Emissions and Environmental Regulations. Presented at the Forest Products Society Conference Quality Drying: The Key to Profitable Manufacturing, September 23 25, 2002, Montreal, Quebec, Canada.

17. Milota, M., Oregon State University. HAP and VOC Emissions From White Fir Lumber Dried at High and Conventional Temperatures. Forest Products Journal, March 2003.

18. M. Lavery and M. Milota, Oregon State University. VOC Emissions from Douglas Fir: Comparing a Commercial and a Laboratory Kiln. Forest Products Journal, Vol 50, No. 7/ 8. March 1999.

19. Memorandum from K. Hanks, RTI to M. Kissell, EPA/ ESD. February 21, 2005. Considerations for a Small scale Kiln Emission Testing Program.

20. U. S. EPA, Air Emissions Models for Waste and Wastewater. EPA 453/ R 94 080A. November 1994.

21. Memorandum from R. Nicholson and K. Hanks, RTI to M. Kissell, EPA/ ESD. November 8, 2004. Meeting Minutes for the October 29, 2004 Meeting Between the U. S. Environmental Protection Agency ( EPA), the American Forest and Paper Association ( AF& PA), and Representatives of the PCWP Industry. ATTACHMENT 1 Table 1 of the Preamble to the Final Rule TABLE 1 OF THE PREAMBLE TO THE FINAL PCWP RULE TABLE 1. PROCESS UNITS THAT ARE SUBJECT TO THE FINAL CONTROL REQUIREMENTS For the following process units... Does today's final rule include control requirements for...

Existing affected sources? New affected sources?

Softwood veneer dryersa; primary tube dryers; secondary tube dryers; rotary strand dryers; conveyor strand dryers; green rotary dryers; hardboard ovens; reconstituted wood product presses; and pressurized refiners Yes Yes Press predryers; fiberboard mat dryers; and board coolers No Yes Dry rotary dryersa; veneer redryersa; softwood plywood presses; hardwood plywood presses; engineered wood products presses; hardwood veneer dryersa; humidifiers; atmospheric refiners; formers; blenders; rotary agricultural fiber dryers; agricultural fiber board presses; sanders; saws; fiber washers; chippers; log vats; lumber kilns; storage tanks; wastewater operations; miscellaneous coating operations ( including group 1 miscellaneous coating operationsa); and stand alone digesters No No aThese process units have work practice requirements in today's final rule in addition to or instead of control requirements. Group 1 miscellaneous coating operations include application of edge seals, nail lines, logo ( or other information) paint, shelving edge fillers, trademark/ grade stamp inks, and wood putty patches to PCWP ( except kiln dried lumber) on the same site where the PCWP are manufactured. Group 1 miscellaneous coating operations also include application of synthetic patches to plywood at new affected sources. ATTACHMENT 2 Suggested Process Unit Definitions Agricultural fiber board press means a press used in the production of an agricultural fiber based composite wood product. An agricultural fiber board press is a process unit.

Agricultural fiberboard mat dryer means a dryer used to reduce the moisture of wet formed agricultural fiber mats by operation at elevated temperature. An agricultural fiberboard mat dryer is a process unit.

Atmospheric refiner means a piece of equipment operated under atmospheric pressure for refining ( rubbing or grinding) the wood material into fibers or particles. Atmospheric refiners are operated with continuous infeed and outfeed of wood material and atmospheric pressures throughout the refining process. An atmospheric refiner is a process unit.

Blending and forming operations means the process of mixing adhesive and other additives with the ( wood) furnish of the composite panel and making a mat of resinated fiber, particles, or strands to be compressed into a reconstituted wood product such as particleboard, oriented strandboard, or medium density fiberboard. Blending and forming operations are process units.

Fiber washer means a unit in which water soluble components of wood ( hemicellulose and sugars) that have been produced during digesting and refining are removed from the wood fiber. Typically wet fiber leaving a refiner is further diluted with water and then passed over a filter, leaving the cleaned fiber on the surface. A fiber washer is a process unit.

Finishing sander means a piece of equipment that uses an abrasive drum, belt, or pad to impart smoothness to the surface of a plywood or composite wood product panel and to reduce the panel to the prescribed thickness. A finishing sander is a process unit.

Finishing saw means a piece of equipment used to trim or cut finished plywood and composite wood products panels to a certain size. A finishing saw is a process unit.

Hardwood plywood press means a hot press which, through heat and pressure, bonds assembled hardwood veneers ( including multiple plies of veneer and/ or a substrate) and resin into a hardwood plywood panel. A hardwood plywood press is a process unit.

Hardwood veneer kiln means an enclosed dryer operated in batch cycles at elevated temperature to reduce the moisture content from stacked hardwood veneer. A hardwood veneer kiln is a process unit.

Humidifier means a process unit used to increase the moisture content of hardboard following pressing or after post baking. Typically, water vapor saturated air is blown over the hardboard surfaces in a closed cabinet. A humidifier is a process unit.

I joist curing chamber means an oven or a room surrounded by a solid wall or heavy plastic flaps that uses heat, infrared, or radio frequency techniques to cure the adhesive. An I joist curing chamber is a process unit. Log chipping means the production of wood chips from logs.

Log vat means a process unit that raises the temperature of the logs inside by applying a heated substance, usually hot water and steam, to the outside of the logs by spraying or soaking. A log vat is a process unit.

LSL press means a composite wood product press that presses a loose mat of resinated strands into a billet by simultaneous application of heat and pressure and forms laminated strand lumber. An LSL press is a process unit.

LVL press means a composite wood product press that presses resinated stacks of veneers into a solid billet by simultaneous application of heat and pressure and forms laminated veneer lumber or parallel strand lumber. An LVL press is a process unit.

Natural gas means a naturally occurring mixture of hydrocarbon and non hydrocarbon gases found in geologic formations beneath the earth's surface. The principal hydrocarbon constituent is methane.

Paddle type particleboard dryer means a dryer that uses elevated temperature to remove moisture from particles and paddles to advance materials through the dryer. This type of dryer removes moisture absorbed by particles due to high ambient temperature. A paddle type particleboard dryer is a process unit.

Panel trim chipper means a piece of equipment that accepts the discarded pieces of veneer or pressed plywood and composite wood products panels that are removed by finishing saws and reduces these pieces to small elements. A panel trim chipper is a process unit.

Particleboard extruder means a heated die oriented either horizontally or vertically through which resinated particles are continuously forced to form extruded particleboard products. A particleboard extruder is a process unit.

Particleboard press mold means a press that consists of molds that apply heat and pressure to form molded or shaped particleboard products. A particleboard press mold is a process unit.

Propane means a colorless gas derived from petroleum and natural gas, with the molecular structure C3H8.

Radio frequency veneer redryer means a dryer heated by radio frequency waves that is used to redry veneer that has been previously dried. A radio frequency veneer redryer is a process unit.

Resin storage tank means any storage tank, container, or vessel connected to plywood and composite wood product production that contains resin additives. A resin storage tank is a process unit. Rotary agricultural fiber dryer means a rotary dryer operated at elevated temperature and used to reduce the moisture of agricultural fiber. A rotary agricultural fiber dryer is a process unit.

Softwood plywood press means a hot press which, through heat and pressure, bonds assembled softwood veneer plies and resin into a softwood plywood panel. A softwood plywood press is a process unit.

Softwood veneer kiln means an enclosed dryer operated in batch cycles at elevated temperature to reduce the moisture content from stacked softwood veneer. A softwood veneer kiln is a process unit.

Stand alone digester means a pressure vessel used to heat and soften wood chips ( usually by steaming) before the chips are sent to a separate process unit for refining into fiber. A stand alone digester is a process unit.

Wastewater/ process water operation means equipment that stores, transfer, or processes water in plywood or composite wood product facilities for reuse or disposal. Wastewater/ process water operations includes but is not limited to pumps, holding ponds and tanks, cooling and heating operations, settling systems, filtration systems, aeration systems, clarifiers, pH adjustment systems, log storage ponds, pollution control device water ( including wash water), vacuum distillation systems, sludge drying and disposal systems, spray irrigation fields, and connections to POTW facilities. Wastewater/ process water operations are process units. ATTACHMENT 3 Comparison of Selected HAP Data from Similar Process Units on the Same Site Shaded rows indicate that one or both of the units had all non detect measurements for the pollutant. Therefore, a comparison between the two units could not be made.

Softwood Plywood Softwood Plywood Hot Board Press, Unpowered Vent Above No. 1 Board Press Softwood Plywood Hot Board Press, Powered Vent Above No. 2 Board Press Difference is a factor of...

Unit code Compound Name No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ MSF 3/ 8" Unit code Compound Name No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ MSF 3/ 8" lb/ hr EF 194 1PB1 acetaldehyde 1 0.46448581 0.012153016 0.00082734 194 2PB1 acetaldehyde 1 0.472162201 0.0712776 0.005080149 6 6 194 1PB1 acrolein 3 0.14440155 0.004835673 0.000375947 194 2PB1 acrolein 3 0.134470272 0.026037815 0.001940698 5 5 194 1PB1 benzene 3 0.044935273 0.002097932 0.000166345 194 2PB1 benzene 3 0.038813141 0.010472174 0.000776091 5 5 194 1PB1 formaldehyde 3 0.06452301 0.001158353 9.01062E 05 194 2PB1 formaldehyde 0 0.748626676 0.077121794 0.005433552 194 1PB1 methanol 0 42.21742058 0.805872903 0.060465713 194 2PB1 methanol 0 29.2907602 3.237752642 0.245075359 4 4 194 1PB1 phenol 3 0.173311705 0.009742617 0.000756299 194 2PB1 phenol 3 0.162273289 0.052748018 0.003933065 5 5 194 1PB1 propionaldehyde 3 0.156943298 0.005444923 0.000423008 194 2PB1 propionaldehyde 3 0.146531724 0.029395615 0.002191383 5 5 194 1PB1 THC as carbon 0 213.8162995 1.529139198 0.108983943 194 2PB1 THC as carbon 0 121.6809338 5.038749275 0.371976595 3 3 Note: The two presses are similar in design and operation; however, the press vent fan was not operating during testing of the No. 1 press. It is common for plywood plants to turn off press vent fans during winter months.

Softwood Veneer Dryer, No. 2 Combined Vent Softwood Veneer Dryer, No. 3 Combined Vent Difference is a factor of...

Unit code Compound Name No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ MSF 3/ 8" Unit code Compound Name No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ MSF 3/ 8" lb/ hr EF 170 2DV3 acetaldehyde 0 4.986850046 0.207141187 0.014777546 170 3DV3 acetaldehyde 0 4.594664188 0.217047936 0.020057348 1 1 170 2DV3 acrolein 3 0.145967739 0.007730051 0.000555108 170 3DV3 acrolein 3 0.137141817 0.008252651 0.000746565 1 1 170 2DV3 benzene 3 0.043713345 0.003234073 0.000230178 170 3DV3 benzene 3 0.038217993 0.003205574 0.000289046 1 1 170 2DV3 formaldehyde 0 3.307519969 0.094966505 0.00662101 170 3DV3 formaldehyde 0 2.149834815 0.06880423 0.006847769 1 1 170 2DV3 methanol 0 11.72177747 0.357249181 0.024774387 170 3DV3 methanol 0 16.50106713 0.563826277 0.053555672 2 2 170 2DV3 phenol 3 0.17568827 0.015615904 0.001122127 170 3DV3 phenol 2 0.245063977 0.024819513 0.002100491 170 2DV3 propionaldehyde 3 0.158861043 0.008715177 0.000626045 170 3DV3 propionaldehyde 3 0.149615168 0.009327549 0.000843892 1 1 170 2DV3 THC as carbon 0 170 3DV3 THC as carbon 0 NA NA Shaded rows indicate that one or both of the units had all non detect measurements for the pollutant. Therefore, a comparison between the two units could not be made.

Particleboard Face Dryer, Face Dryer Exhaust Core Dryer, Core Dryer Exhaust Difference is a factor of...

Unit code Compound Name No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ ODT Unit code Compound Name No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ ODT lb/ hr EF 010 1DR1 acetaldehyde 3 0.245693 0.034367 0.00346968 010 3DR1 acetaldehyde 1 0.339660414 0.063538179 0.00597121 010 1DR1 acrolein 3 0.168769 0.030043 0.00303345 010 3DR1 acrolein 3 0.138595029 0.032929559 0.003041719 1 1 010 1DR1 benzene 3 0.038567 0.009566 0.00096683 010 3DR1 benzene 3 0.036373043 0.012040173 0.001114467 1 1 010 1DR1 formaldehyde 1 0.730361 0.066318 0.00698802 010 3DR1 formaldehyde 1 0.201909989 0.025797667 0.002440519 3 3 010 1DR1 methanol 1 0.953652 0.095366 0.00980276 010 3DR1 methanol 0 0.731112968 0.099331013 0.009148015 1 1 010 1DR1 phenol 3 0.206613 0.061744 0.0062339 010 3DR1 phenol 3 0.168306139 0.067131034 0.006200116 1 1 010 1DR1 propionaldehyde 3 0.185186 0.034154 0.00344838 010 3DR1 propionaldehyde 3 0.151484246 0.037288973 0.003444183 1 1 010 1DR1 THC as carbon 0 303.2183 11.24008 1.14800631 010 3DR1 THC as carbon 0 369.8208801 18.8026253 1.717294871 2 1 Single Pass Rotary Dryer, No. 1 Dryer Exhaust at Inlet to Sand Filter Single Pass Rotary Dryer, No. 2 Dryer Exhaust at Inlet to Sand Filter Difference is a factor of...

Unit code Compound Name No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ ODT Unit code Compound Name No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ ODT lb/ hr EF 156 1DR2 acetaldehyde 0 6.298317 0.266576 0.03846574 156 2DR2 acetaldehyde 0 3.644912777 0.123389764 0.017715837 2 2 156 1DR2 acrolein 0 1.148655 0.060765 0.0085498 156 2DR2 acrolein 0 0.675011417 0.031308427 0.004597277 2 2 156 1DR2 benzene 0 0.266292 0.020069 0.00291395 156 2DR2 benzene 0 0.283215933 0.018086038 0.002619596 1 1 156 1DR2 formaldehyde 0 28.6228 0.831995 0.1211222 156 2DR2 formaldehyde 0 39.69079318 0.905533725 0.128615158 1 1 156 1DR2 methanol 0 13.93286 0.437496 0.06483169 156 2DR2 methanol 0 6.240498153 0.154039528 0.022075515 3 3 156 1DR2 phenol 2 0.325332 0.029131 0.00417624 156 2DR2 phenol 2 2.204286224 0.140484013 0.019465307 5 5 156 1DR2 propionaldehyde 1 0.444226 0.024437 0.00345657 156 2DR2 propionaldehyde 2 0.269174036 0.011915715 0.001705231 2 2 156 1DR2 THC as carbon NA 156 2DR2 THC as carbon 0 681.7146792 6.892782535 1.003151632 NA NA Shaded rows indicate that one or both of the units had all non detect measurements for the pollutant. Therefore, a comparison between the two units could not be made.

MDF Mill 132, Core Primary Tube Dryer, Cyclone No. 1 Exhaust Mill 132, Core Primary Tube Dryer, Cyclone No. 2 Exhaust Difference is a factor of...

Unit Code Pollutant No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ ODT Unit Code Pollutant No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ ODT lb/ hr EF 132 3DT2 acetaldehyde 1 0.6901488 0.20420389 0.01318659 132 4DT2 acetaldehyde 3 0.405977268 0.123873621 0.00799863 132 3DT2 acrolein 3 0.2865889 0.10814606 0.00698264 132 4DT2 acrolein 3 0.282530507 0.109713022 0.007084261 1 1 132 3DT2 benzene 3 0.0810327 0.04259064 0.00275002 132 4DT2 benzene 3 0.073584126 0.039820816 0.002571239 1 1 132 3DT2 HCHO 0 67.497084 13.605031 0.87874812 132 4DT2 HCHO 0 69.03227911 14.39266599 0.928902276 1 1 132 3DT2 methanol 0 16.810945 3.61984076 0.2337382 132 4DT2 methanol 0 19.85027718 4.398330743 0.283980461 1 1 132 3DT2 phenol 2 0.3765141 0.23862014 0.01540593 132 4DT2 phenol 3 0.343261366 0.223766707 0.01444881 132 3DT2 propionaldehyde 3 0.3125076 0.12217724 0.00788858 132 4DT2 propionaldehyde 3 0.308876653 0.124265059 0.0080239 1 1 132 3DT2 THC as Carbon 0 554.36610 44.7336775 2.88857857 132 4DT2 THC as Carbon 0 551.631776 45.85477023 2.960983019 1 1 Mill 132, Face Primary Tube Dryer, Cyclone No. 1 Exhaust Mill 132, Face Primary Tube Dryer, Cyclone No. 2 Exhaust Difference is a factor of...

Unit Code Pollutant No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ ODT Unit Code Pollutant No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ ODT lb/ hr EF 132 1DT2 acetaldehyde 0 0.6218759 0.20244813 0.01300321 132 2DT2 acetaldehyde 1 0.455371432 0.144821482 0.009289757 1 1 132 1DT2 acrolein 3 0.2805112 0.11527821 0.00736218 132 2DT2 acrolein 3 0.285060456 0.115723838 0.007385353 1 1 132 1DT2 benzene 3 0.0784615 0.0451317 0.00288426 132 2DT2 benzene 3 0.075501674 0.042656442 0.00272596 1 1 132 1DT2 HCHO 0 51.674414 11.3204262 0.72010307 132 2DT2 HCHO 0 53.9323635 11.69498515 0.742915164 1 1 132 1DT2 methanol 0 12.950132 3.04499093 0.1949183 132 2DT2 methanol 0 11.88362891 2.75839531 0.175613018 1 1 132 1DT2 phenol 3 0.3392376 0.2339648 0.01494136 132 2DT2 phenol 1 0.367392989 0.250827118 0.015976969 132 1DT2 propionaldehyde 3 0.3059878 0.13025985 0.0083188 132 2DT2 propionaldehyde 3 0.31148382 0.131011819 0.008360668 1 1 132 1DT2 THC as Carbon 0 555.17772 49.0744696 3.13485248 132 2DT2 THC as Carbon 0 565.4347952 49.14980447 3.133594959 1 1 Shaded rows indicate that one or both of the units had all non detect measurements for the pollutant. Therefore, a comparison between the two units could not be made.

LVL Mill 411, LVL Line, LVL Hot Press No. 1 Mill 411, LVL Line, LVL Hot Press No. 2 Difference is a factor of...

Unit Code Pollutant No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ MCF Unit Code Pollutant No.

ND Avg, ppm Avg, lb/ hr Avg, lb/ MCF lb/ hr EF 411 1PB1 acetaldehyde 3 3.8E 01 0.15028807 1.11324493 411 2PB1 acetaldehyde 3 4.1E 01 0.137131383 1.015788024 1 1 411 1PB1 acrolein 3 2.7E 01 0.13419039 0.99400292 411 2PB1 acrolein 3 2.9E 01 0.122281785 0.905790997 1 1 411 1PB1 benzene 3 7.6E 02 0.05237325 0.38795002 411 2PB1 benzene 3 7.9E 02 0.047183691 0.349508821 1 1 411 1PB1 HCHO 3 1.2E 01 0.03312057 0.24533756 411 2PB1 HCHO 2 1.5E 01 0.034446123 0.255156466 411 1PB1 methanol 0 1.5E+ 00 0.42582331 3.15424673 411 2PB1 methanol 0 1.9E+ 00 0.47469556 3.516263404 1 1 411 1PB1 phenol 3 3.3E 01 0.27240528 2.01781687 411 2PB1 phenol 3 3.5E 01 0.248420623 1.840152765 1 1 411 1PB1 propionaldehyde 3 2.9E 01 0.15164512 1.12329718 411 2PB1 propionaldehyde 3 3.1E 01 0.138238298 1.02398739 1 1 411 1PB1 THC as Carbon 0 1.4E+ 01 1.5070702 11.1634829 411 2PB1 THC as Carbon 0 2.1E+ 01 1.949153907 14.43817709 1 1 ATTACHMENT 4 Available Appendix B HAP Emission Factors for Process Unit Groups Sort EF for App B amendment. xls Acetaldehyde 8/ 24/ 2004 Em. Fact. Process Unit Description Pollutant No. of tests No. of process units No. of runs No. of BDL runs APCD Emission factor EF units MACT floor process unit group Min Max Avg FB, atmospheric refiner and dump chest, softwood Acetaldehyde 1 1 3 0 NONE 2.7E 03 lb/ ODT atmospheric refiner PB flaker/ refiner/ hammermill Acetaldehyde 2 2 6 6 NONE BDL lb/ ODT atmospheric refiner, etc MDF paddle blender, UF resin Acetaldehyde 1 1 3 3 NONE BDL lb/ ODT blender OSB blender ( PF & MDI resin) Acetaldehyde 1 1 3 3 NONE BDL lb/ MSF 3/ 8 blender HB log chipper, hardwood Acetaldehyde 1 1 2 2 NONE BDL lb/ ODT chipper SPW dry trim chipper ( chips dry trim from SPW panel saws; process rate = finished board production) Acetaldehyde 1 1 3 3 NONE BDL lb/ MSF 3/ 8 chipper SV dry trim chipper ( chips trimmed veneer from layup line; process rate =

finished board production) Acetaldehyde 1 1 3 2 NONE 8.1E 04 lb/ MSF 3/ 8 chipper I Joist curing chamber Acetaldehyde 1 1 3 3 NONE BDL lb/ MLF engineered wood products press LVL, press, PF resin Acetaldehyde 1 1 6 5 NONE 2.9E 01 lb/ 1000 ft3 engineered wood products press FB, washer, softwood Acetaldehyde 1 1 3 0 NONE 1.5E 02 lb/ ODT fiber washer FB, board dryer, indirect heated, softwood, 6 12% asphalt binder ( heated zones) Acetaldehyde 2 1 18 8 NONE 1.4E 03 4.4E 03 2.9E 03 lb/ MSF 1/ 2 fiberboard mat dryer FB, board dryer, indirect heated, softwood, starch binder ( heated zones) Acetaldehyde 1 1 9 6 NONE 9.7E 04 lb/ MSF 1/ 2 fiberboard mat dryer HB, board dryer, direct natural gas fired, softwood, linseed oil binder ( heated zones) Acetaldehyde 1 1 6 0 NONE 5.3E 02 lb/ MSF 1/ 2 fiberboard mat dryer FB, board dryer fugitive emissions, indirect heated, softwood, 6 12%

asphalt binder Acetaldehyde 2 1 12 11 NONE 5.0E 03 5.5E 03 5.2E 03 lb/ MSF 1/ 2 fiberboard mat dryer ( fugitive)

FB, former, wet, 6 12% asphalt Acetaldehyde 1 1 9 5 NONE 7.5E 03 lb/ MSF 1/ 2 former HB former, wet, PF resin Acetaldehyde 3 1 9 0 NONE 4.4E 03 6.7E 03 5.8E 03 lb/ ODT former MDF former with blowline blend, UF resin Acetaldehyde 2 2 6 6 NONE BDL lb/ ODT former MDF former without blowline blend, UF resin ( includes blender emissions) Acetaldehyde 1 1 3 3 NONE BDL lb/ ODT former, blender MDF, green dryer, rotary, direct natural gas fired, softwood Acetaldehyde 2 1 6 6 NONE BDL lb/ ODT green rotary dryer PB, green dryer, rotary, direct wood fired, mixed wood species ( 40 60%

softwood, 40 60% hardwood) Acetaldehyde 6 8 18 0 NONE 5.2E 03 1.2E 01 5.9E 02 lb/ ODT green rotary dryer PB, green dryer, rotary, direct wood fired, softwood Acetaldehyde 4 2 15 0 NONE 7.0E 02 8.1E 02 7.5E 02 lb/ ODT green rotary dryer PB, rotary, direct wood fired, softwood Acetaldehyde 6 4 21 4 NONE 3.5E 03 3.2E 02 1.3E 02 lb/ ODT dry rotary dryer HB, tempering oven, direct natural gas fired Acetaldehyde 1 1 3 0 NONE 7.6E 02 lb/ MSF 1/ 8 hardboard oven HPW, veneer, indirect heated, hardwood ( cooling section) Acetaldehyde 7 4 21 12 NONE 1.7E 02 5.8E 02 3.2E 02 lb/ MSF 3/ 8 hardwood veneer dryer ( cooling)

HPW, veneer, direct wood fired, hardwood ( cooling section) Acetaldehyde 1 1 3 3 NONE BDL lb/ MSF 3/ 8 hardwood veneer dryer ( cooling)