Appendix B to Subpart DDDD of Part 63 - Methodology and Criteria for Demonstrating That an Affected Source Is Part of the Low-Risk Subcategory of Plywood and Composite Wood Products Manufacturing Affected Sources  

This appendix provides the methodology and criteria for demonstrating that your affected source is part of the low-risk subcategory of plywood and composite wood products (PCWP) manufacturing facilities. You must demonstrate that your affected source is part of the low-risk subcategory using either a look-up table analysis (based on the look-up tables included in this appendix) or using a site-specific risk assessment performed according to the criteria specified in this appendix. This appendix also specifies how and when you must obtain approval of the low-risk demonstrations for your affected source and how to ensure that your affected source remains in the low-risk subcategory of PCWP facilities.

Each new, reconstructed, or existing affected source at a PCWP manufacturing facility may demonstrate that they are part of the low-risk subcategory of PCWP affected sources. Section 63.2232 of 40 CFR part 63, subpart DDDD, defines the affected source and explains which affected sources are new, existing, or reconstructed.

Every process unit that is part of the PCWP affected source (as defined in § 63.2292 of 40 CFR part 63, subpart DDDD) and that emits one or more hazardous air pollutant (HAP) listed in table 1 to this appendix must be included in the low-risk demonstration. You are not required to include process units outside of the affected source in the low-risk demonstration.

(a) Determine the individual HAP emission rates from each process unit emission point within the affected source using the procedures specified in section 5 of this appendix.

(b) Perform chronic and acute risk assessments using the dose-response values, as specified in paragraphs (b)(1) through (3) of this section.

(1) For a look-up table analysis or site-specific chronic inhalation risk assessment, you should use the cancer and noncancer dose-response values listed on the Environmental Protection Agency (EPA) Air Toxics Web site (http://www.epa.gov/ttn/atw/toxsource/summary.html) to estimate carcinogenic and noncarcinogenic chronic inhalation risk, respectively.

(2) For site-specific acute inhalation risk assessment, you should use the acute exposure guidance level (AEGL-1) value for acrolein and the acute reference exposure level (REL) value for formaldehyde for estimating acute inhalation risk found at http://www.epa.gov/ttn/atw/toxsource/summary.html.

(3) You may use dose-response values more health-protective than those posted on the EPA Air Toxics Web site (http://www.epa.gov/ttn/atw/toxsource/summary.html) to facilitate ongoing certification (as required in section 13 of this appendix) that your affected source remains in the low-risk subcategory.

(c) Demonstrate that your affected source is part of the low-risk subcategory by estimating the maximum impacts of your affected source using the methods described in either section 6 of this appendix (look-up table analysis) or section 7 of this appendix (site-specific risk assessment) and comparing the results to the low-risk criteria presented in the applicable section.

(a) You must determine HAP emissions for every process unit emission point within the affected source that emits one or more of the HAP listed in table 1 to this appendix as specified in table 2A to this appendix. For each process unit type, table 2A to this appendix specifies whether emissions testing is required or if emissions estimation is allowed as an alternative to emissions testing. If emissions estimation is allowed according to table 2A, you must develop your emission estimates according to the requirements in paragraph (k) of this section. You may choose to perform emissions testing instead of emissions estimation. You must conduct HAP emissions tests according to the requirements in paragraphs (b) through (j) of this section and the methods specified in table 2B to this appendix. If you conduct fuel analyses, you must follow the requirements of paragraph (m) of this section. For each of the emission points at your affected source, you must obtain the emission rates in pounds per hour (lb/hr) for each of the pollutants listed in table 1 to this appendix.

(b) Periods when emissions tests must be conducted.

(1) You must not conduct emissions tests during periods of startup, shutdown, or malfunction, as specified in 40 CFR 63.7(e)(1).

(2) You must test under worst-case operating conditions as defined in this appendix. You must describe your worst-case operating conditions in your performance test report for the process and control systems (if applicable) and explain why the conditions are worst-case.

(c) Number of test runs. You must conduct three separate test runs for each test required in this section, as specified in 40 CFR 63.7(e)(3). Each test run must last at least 1 hour except for: testing of a temporary total enclosure (TTE) conducted using Methods 204A through 204F in 40 CFR part 51, appendix M, which require three separate test runs of at least 3 hours each; and testing of an enclosure conducted using the alternative tracer gas method in appendix A to 40 CFR part 63, subpart DDDD, which requires a minimum of three separate runs of at least 20 minutes each.

(d) Sampling locations. Sampling sites must be located at the emission point and prior to any releases to the atmosphere. For example, at the outlet of the control device, including wet control devices, and prior to any releases to the atmosphere.

(e) Collection of monitoring data for HAP control devices. During the emissions test, you must collect operating parameter monitoring system or continuous emissions monitoring system (CEMS) data at least every 15 minutes during the entire emissions test and establish the site-specific operating requirements (including the parameter limits or total hydrocarbon (THC) concentration limit) in table 2 to 40 CFR part 63, subpart DDDD, using data from the monitoring system and the procedures specified in paragraphs (k) through (o) of § 63.2262 of subpart DDDD of 40 CFR part 63.

(f) Nondetect data. You may treat emissions of an individual HAP as zero if all of the test runs result in a nondetect measurement and the conditions in paragraphs (1) and (2) of this section are met for the relevant test method. Otherwise, nondetect data (as defined in § 63.2292 of 40 CFR part 63, subpart DDDD) for individual HAP must be treated as one-half of the method detection limit.

(1) The method detection limit is less than or equal to 1 part per million by volume, dry (ppmvd) for pollutant emissions measured using Method 320 in appendix A to 40 CFR part 63; or Method 18 in appendix A to 40 CFR part 60; or the NCASI Method IM/CAN/WP-99.02 (incorporated by reference (IBR), see 40 CFR 63.14(f)); or NCASI Method ISS/FP-A105.01 (IBR, see 40 CFR 63.14(f); or ASTM D6348-03 (IBR, see 40 CFR 63.14(b)).

(2) For pollutants measured using Method 29 in appendix A to 40 CFR part 60, you analyze samples using atomic absorption spectroscopy (AAS) or another laboratory method specified in Method 29 in appendix A to 40 CFR part 60 with detection limits lower than or equal to AAS.

(g) For purposes of your low-risk demonstration, you must assume that 17 percent of your total chromium measured using EPA Method 29 in appendix A to 40 CFR part 60 is chromium VI. You must assume that 65 percent of your total nickel measured using EPA Method 29 in appendix A to 40 CFR part 60 is nickel subsulfide.

(h) You may use emission rates higher than your measured emission rates (e.g., emissions rates 10 times your measured emission rate) to facilitate ongoing certification (as required in section 13 of this appendix) that your affected source remains in the low-risk subcategory.

(i) Use of previous emissions tests. You may use the results of previous emissions tests provided that the following conditions are met:

(1) The previous emissions tests must have been conducted using the methods specified in table 2B to this appendix. Previous emission test results obtained using NCASI Method IM/CAN/WP-99.01 are acceptable.

(2) The previous emissions tests must meet the requirements in paragraphs (b) through (j) of this section.

(3) The subject process unit(s) must be operated in a manner (e.g., with raw material type, operating temperature, etc.) that would be expected to result in the same or lower emissions than observed during the previous emissions test(s) and the process unit(s) may not have been modified such that emissions would be expected to exceed (notwithstanding normal test-to-test variability) the results from previous emissions test(s).

(4) The previous emissions test(s) must have been conducted in 1997 or later.

(j) Use of test data for similar process units. If you have multiple similar process units at the same plant site, you may apply the test results from one of these process units to the other similar process units for purposes of your low-risk demonstration provided that the following conditions are met:

(1) You must explain how the process units are similar in terms of design, function, heating method, raw materials processed, residence time, change in material moisture content, operating temperature, resin type processed, age, and any other parameters that may affect emissions.

(2) If the process units have different throughput rates, then you must 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.

(3) If one of the process units would be expected to exhibit higher emissions due to minor differences in process parameters, then you must explain and test the process unit that would be expected to exhibit greater emissions (for example, the unit with a slightly higher temperature set point, dryer processing furnish with slightly higher inlet moisture content, press processing thicker panels, unit with the greater throughput, considerably older unit, etc.).

(k) If emissions estimation is allowed, you must follow the procedures in (1) through (3) of this paragraph.

(1) You must use the emission factors or other emission estimation techniques specified in table 2A to this appendix when developing emission estimates.

(2) You must base your emission estimates on the maximum process unit throughput you will incorporate into your permit according to section 11(b) of this appendix.

(3) For process units with multiple emission points, you must apportion the estimate emissions evenly across each emission point. For example, if you have a process unit with two emission points, and the process unit is estimated to emit 6 lb/hr, you would assign 3 lb/hr to each emission point.

(l) Testing of multiple stacks. You may test one of multiple stacks for a process unit provided that the following conditions are met:

(1) The emissions are produced by the same process unit.

(2) The emissions originate from the same duct.

(3) The emissions are sufficiently mixed so that the gaseous pollutant concentrations from one stack are not expected to differ from concentrations from another stack.

(m) Conducting a fuel analysis. For process units that require testing of metals according to table 2A to this appendix, you may conduct a fuel analysis in lieu of emissions tests. You must follow the procedures described in § 63.7521 (a) and (c) through (e) of subpart DDDDD; § 63.7530(d)(1), (2), and (4) of subpart DDDDD, and line 2 of table 6 to subpart DDDDD. For purposes of this appendix, the total selected metals analyzed by fuel analysis are the metals included in table 1 to this appendix.

Use the look-up tables (tables 3 and 4 to this appendix) to demonstrate that your affected source is part of the low-risk subcategory, following the procedures in paragraphs (a) through (d) of this section.

(a) Using the emission rate of each HAP required to be included in your low-risk demonstration (determined according to section 5 of this appendix), calculate your total toxicity-weighted carcinogen and noncarcinogen emission rates for each of your emission points using Equations 1 and 2 of this appendix, respectively. Calculate your carcinogen and non-carcinogen weighted stack height using Equations 3 and 4 of this appendix, respectively.

(b) Cancer risk. Calculate the total toxicity-weighted carcinogen emission rate for your affected source by summing the toxicity-weighted carcinogen emission rates for each of your emission points. Identify the appropriate maximum allowable toxicity-weighted carcinogen emission rate from table 3 to this appendix for your affected source using the carcinogen weighted stack height of your emission points and the minimum distance between any emission point at the affected source and the property boundary. If one or both of these values do not match the exact values in the look-up table, then use the next lowest table value. (Note: If your weighted stack height is less than 5 meters (m), you must use the 5 m row.) Your affected source is considered low risk for carcinogenic effects if your toxicity-weighted carcinogen emission rate, determined using the methods specified in this appendix, does not exceed the values specified in table 3 to this appendix.

(c) Noncancer risk. Calculate the total central nervous system (CNS) and respiratory target organ specific toxicity-weighted noncarcinogen emission rate for your affected source by summing the toxicity-weighted emission rates for each of your emission points. Identify the appropriate maximum allowable toxicity-weighted noncarcinogen emission rate from table 4 to this appendix for your affected source using the non-carcinogen weighted stack height of your emission points and the minimum distance between any emission point at the affected source and the property boundary. If one or both of these values do not match the exact values in the look-up table, then use the next lowest table value. (Note: If your weighted stack height is less than 5 m, you must use the 5 m row.) Your affected source is considered low risk for noncarcinogenic effects if your toxicity-weighted noncarcinogen emission rate, determined using the methods specified in this appendix, does not exceed the values specified in table 4 to this appendix.

(d) Low-risk demonstration. The EPA will approve your affected source as eligible for membership in the low-risk subcategory of PCWP affected sources if it determines that: (1) Your affected source is low risk for both carcinogenic and noncarcinogenic effects using the look-up table analysis described in this section and (2) you meet the criteria specified in section 11 of this appendix.

(a) Perform a site-specific risk assessment following the procedures specified in this section. You may use any scientifically-accepted peer-reviewed assessment methodology for your site-specific risk assessment. An example of one approach to performing a site-specific risk assessment for air toxics that may be appropriate for your affected source can be found in the “Air Toxics Risk Assessment Guidance Reference Library, Volume 2, Site-Specific Risk Assessment Technical Resource Document.” You may obtain a copy of the “Air Toxics Risk Assessment Reference Library” through EPA's air toxics Web site at http://www.epa.gov/ttn/fera/risk_atra_main.html.

(b) At a minimum, your site-specific risk assessment must:

(1) Estimate the long-term inhalation exposures through the estimation of annual or multi-year average ambient concentrations for the chronic portion of the assessment.

(2) Estimate the acute exposures for formaldehyde and acrolein through the estimation of maximum 1-hour average ambient concentrations for the acute portion of the assessment.

(3) Estimate the inhalation exposure of the individual most exposed to the affected source's emissions.

(4) Estimate the individual risks over a 70-year lifetime for the chronic cancer risk assessment.

(5) Use site-specific, quality-assured data wherever possible.

(6) Use health-protective default assumptions wherever site-specific data are not available.

(7) Contain adequate documentation of the data and methods used for the assessment so that it is transparent and can be reproduced by an experienced risk assessor and emission measurement expert.

(c) Your site-specific risk assessment need not:

(1) Assume any attenuation of exposure concentrations due to the penetration of outdoor pollutants into indoor exposure areas.

(2) Assume any reaction or deposition of the emitted pollutants during transport from the emission point to the point of exposure.

(d) Your affected source is considered low risk for carcinogenic chronic inhalation effects if your site-specific risk assessment demonstrates that maximum off-site individual lifetime cancer risk at a location where people live or congregate (e.g., school or day care center) is less than 1 in 1 million.

(e) Your affected source is considered low risk for noncarcinogenic chronic inhalation effects if your site-specific risk assessment demonstrates that every maximum off-site target-organ specific hazard index (TOSHI), or appropriate set of site-specific hazard indices based on similar or complementary mechanisms of action that are reasonably likely to be additive at low dose or dose-response data for mixtures, at a location where people live is less than or equal to 1.0.

(f) Your affected source is considered low risk for noncarcinogenic acute inhalation effects if your site-specific risk assessment demonstrates that the maximum off-site acute hazard quotients for both acrolein and formaldehyde are less than or equal to 1.0.

(g) The EPA will approve your affected source as eligible for membership in the low-risk subcategory of PCWP affected sources if it determines that: (1) your affected source is low risk for all of the applicable effects listed in paragraphs (d) through (f) of this section and (2) you meet the criteria specified in section 11 of this appendix.

(a) Your low-risk demonstration must include at a minimum the information specified in paragraphs (a)(1) through (5) of this section and the information specified in either paragraph (b) or (c) of this section.

(1) Identification of each process unit at the affected source.

(2) Stack parameters for each emission point including, but not limited to, the parameters listed in paragraphs (a)(2)(i) through (iv) below:

(i) Emission release type.

(ii) Stack height, stack area, stack gas temperature, and stack gas exit velocity.

(iii) Plot plan showing all emission points, nearby residences, and fenceline.

(iv) Identification of any HAP control devices used to reduce emissions from each process unit.

(3) Emission test reports for each pollutant and process unit based on the testing requirements and methods specified in tables 2A and 2B to this appendix, including a description of the process parameters identified as being worst case. You must submit your emissions calculations for each pollutant and process unit for which emissions estimates are developed. You must submit fuel analyses for each fuel and emission point which has been conducted, including collection and analytical methods used.

(4) Identification of the dose-response values used in your risk analysis (look-up table analysis or site-specific risk assessment), according to section 4(b) of this appendix.

(5) Identification of the controlling process factors (including, but not limited to, production rate, emission rate, type of control devices, process parameters documented as worst-case conditions during the emissions testing used for your low-risk demonstration) that will become Federally enforceable permit conditions used to show that your affected source remains in the low-risk subcategory.

(b) If you use the look-up table analysis in section 6 of this appendix to demonstrate that your affected source is low risk, your low-risk demonstration must contain at a minimum the information in paragraphs (a) and (b)(1) through (4) of this section.

(1) Identification of the stack heights for each emission point included in the calculations of weighted stack height.

(2) Identification of the emission point with the minimum distance to the property boundary.

(3) Calculations used to determine the toxicity-weighted carcinogen and noncarcinogen emission rates and weighted stack heights according to section 6(a) of this appendix.

(4) Comparison of the values in the look-up tables (tables 3 and 4 to this appendix) to your toxicity-weighted emission rates for carcinogenic and noncarcinogenic HAP.

(c) If you use a site-specific risk assessment as described in section 7 of this appendix to demonstrate that your affected source is low risk (for carcinogenic and noncarcinogenic chronic inhalation and acute inhalation risks), your low-risk demonstration must contain at a minimum the information in paragraphs (a) and (c)(1) through (8) of this section.

(1) Identification of the risk assessment methodology used.

(2) Documentation of the fate and transport model used.

(3) Documentation of the fate and transport model inputs, including the information described in paragraphs (a)(1) through (4) of this section converted to the dimensions required for the model and all of the following that apply: meteorological data; building, land use, and terrain data; receptor locations and population data; and other facility-specific parameters input into the model.

(4) Documentation of the fate and transport model outputs.

(5) Documentation of exposure assessment and risk characterization calculations.

(6) Comparison of the maximum off-site individual lifetime cancer risk at a location where people live to 1 in 1 million, as required in section 7(d) of this appendix for carcinogenic chronic inhalation risk.

(7) Comparison of the maximum off-site TOSHI for respiratory effects and CNS effects at a location where people live to the limit of 1.0, as required in section 7(e) of this appendix for noncarcinogenic chronic inhalation risk.

(8) Comparison of the maximum off-site acute inhalation hazard quotient (HQ) for both acrolein and formaldehyde to the limit of 1.0, as required in section 7(f) of this appendix for noncancinogenic acute inhalation effects.

(d) The EPA may request any additional information it determines is necessary or appropriate to evaluate an affected source's low-risk demonstration.

You must submit your low-risk demonstration to the EPA for review and approval. Send your low-risk demonstration either by e-mail to REAG@EPA.GOV or by U.S. mail or other mail delivery service to U.S. EPA, Risk and Exposure Assessment Group, Emission Standards Division (C404-01), Attn: Group Leader, Research Triangle Park, NC 27711, and send a copy to your permitting authority. Your affected source is not part of the low-risk subcategory of PCWP facilities unless and until EPA notifies you that it has determined that you meet the requirements of section 11 of this appendix.

(a) Existing affected sources. If you have an existing affected source, you may complete and submit for approval your low-risk demonstration (including the emission test results, fuel analyses, and emission estimates required in this appendix) any time. Existing affected sources that are not approved by EPA as being part of the low-risk subcategory by October 1, 2008, must comply with the requirements of 40 CFR part 63, subpart DDDD from October 1, 2008, unless and until EPA approves them as part of the low-risk subcategory.

(b) Sources in compliance with 40 CFR part 63, subpart DDDD. If you operate an affected source that is already in compliance with 40 CFR part 63, subpart DDDD (including, but not limited to, an existing source, a new or reconstructed affected source starting up before September 28, 2004, or a new source starting up after September 28, 2004, but before February 16, 2006) and wish to become part of the low-risk subcategory, then you may complete and submit for approval your low-risk demonstration (including the emission test results, fuel analyses, and emission estimates required in this appendix) any time. Your affected source will become part of the low-risk subcategory when EPA determines that the requirements in section 11 of this appendix are met.

(c) New or reconstructed affected sources wanting to be part of the low-risk subcategory at startup must comply with the requirements of paragraphs (c)(1) through (c)(3) of this section.

(1)(i) You must complete and submit for review and approval a pre-startup low-risk demonstration no later than nine months prior to initial startup. The pre-startup low-risk demonstration must be based on the information (e.g., equipment types, estimated emission rates, etc.) that you will likely use to obtain your title V permit. You must base your pre-startup low-risk demonstration on the maximum emissions that will likely be allowed when you obtain your title V permit.

(ii) You must request that your affected source become part of the low-risk subcategory based on your pre-startup low-risk demonstration.

(iii) If EPA approves your pre-startup low-risk demonstration, then your affected source will be part of the low-risk subcategory upon approval of the pre-startup low-risk demonstration and you may start up your affected source without complying with the compliance options, operating requirements, and work practice requirements in 40 CFR part 63, subpart DDDD, provided that you operate your affected source consistently with the pre-startup low-risk demonstration until you meet the criteria in section 11 of this appendix based on your verification low-risk demonstration developed according to paragraph (c)(2) of this section. Failure to so operate will render approval of your pre-startup low-risk demonstration null and void from the date you startup your affected source.

(2)(i) You must complete and submit your verification low-risk demonstration, including the results from emission tests (or fuel analyses) required in this appendix, within 240 days following initial startup. The verification low-risk demonstration must demonstrate to EPA's satisfaction that the affected source is low risk. The verification low-risk demonstration may be used to change operating parameters ensuring low-risk status.

(ii) If you do not submit the verification low-risk demonstration as required, or the verification low-risk demonstration does not verify that the affected source is low risk, then approval of your pre-startup low-risk demonstration is null and void from the date you startup your affected source and you must comply immediately with subpart DDDD of 40 CFR part 63.

(3) To incorporate the low-risk parameters from your verification low-risk demonstration into your title V permit, you must submit your application for a significant modification to your title V permit within 1 year following initial startup, or earlier if so required under your State's permit program approved under 40 CFR part 70. The parameters that defined your affected source as part of the low-risk subcategory (including, but not limited to, production rate, emission rate, type of control devices, process parameters reflecting the emissions rates used for your low-risk demonstration, and stack height) must be submitted for incorporation as federally enforceable terms and conditions into your title V permit. You must provide written certification to the permitting authority that your affected source is operating consistently with its EPA-approved pre-startup low-risk demonstration and verification low-risk demonstration, as applicable, from startup until your title V permit revision is issued.

(d) New or reconstructed affected sources that want to operate consistently with a pre-startup low-risk demonstration at startup and become part of the low-risk subcategory based on EPA approval of their verification low-risk demonstration (rather than based on their pre-startup low-risk demonstration), must comply with the requirements in paragraphs (d)(1) through (d)(3) of this section.

(1)(i) You must complete and submit for review a pre-startup low-risk demonstration no later than nine months prior to initial startup. The pre-startup low-risk demonstration must be based on the information (e.g., equipment types, estimated emission rates, etc.) that you will likely use to obtain your title V permit. You must base your pre-startup low-risk demonstration on the maximum emissions that will likely be allowed when you obtain your title V permit.

(ii) If EPA concludes that your pre-startup low-risk demonstration is complete and sufficiently shows that your affected source appears to be eligible for inclusion in the low-risk subcategory, then you must operate your affected source consistently with the pre-startup low-risk demonstration until EPA determines that you meet the criteria in section 11 of this appendix based on your verification low-risk demonstration developed according to paragraph (d)(2) of this section.

(2)(i) You must complete and submit for EPA review and approval your verification low-risk demonstration, including the results from emission tests (or fuel analyses) required in this appendix, within 240 days following initial startup. The verification low-risk demonstration must demonstrate to EPA's satisfaction that the affected source is low risk.

(ii) You will become part of the low-risk subcategory when EPA determines that you meet the criteria in section 11 of this appendix based upon your verification low-risk demonstration. If you do not submit the verification low-risk demonstration as required, or the verification low-risk demonstration does not verify that the affected source is low risk, then EPA will not approve your low-risk demonstration and you will remain subject to subpart DDDD of 40 CFR part 63.

(3) To incorporate the low-risk parameters from your verification low-risk demonstration into your title V permit, you must submit your application for a significant modification to your title V permit within 1 year following initial startup, or earlier if so required by your State's permit program approved by EPA under 40 CFR part 70. The parameters that defined your affected source as part of the low-risk subcategory (including, but not limited to, production rate, emission rate, type of control devices, process parameters reflecting the emissions rates used for your low-risk demonstration, and stack height) must be submitted for incorporation as federally enforceable terms and conditions into your title V permit. You must provide written certification to the permitting authority that your affected source is operating consistently with its pre-startup LRD and your verification LRD, as applicable, from startup until your title V permit revision is issued.

(e) Area sources that become affected sources. If you have an affected source that is an area source that increases its emissions or its potential to emit such that it becomes a major source of HAP before September 28, 2004, then you must complete and submit for approval your low-risk demonstration as specified in paragraph (a) of this section. If you have an affected source that is an area source that increases its emissions or its potential to emit such that it becomes a major source of HAP after September 28, 2004, then you must complete and submit for approval your low-risk demonstration as specified in paragraphs (b), (c) or (d) of this section, whichever applies.

For existing sources to be included in the low-risk subcategory, EPA must find that you meet the criteria in paragraphs (a) and (b) of this section. For new sources to be included in the low-risk subcategory, EPA must find that you meet the criteria in paragraph (a) of this section. Unless and until EPA finds that you meet these criteria, your affected source is subject to the applicable compliance options, operating requirements, and work practice requirements in 40 CFR part 63, subpart DDDD.

(a) Your demonstration of low risk must be approved by EPA.

(b) Following EPA approval, the parameters that defined your affected source as part of the low-risk subcategory (including, but not limited to, production rate, emission rate, type of control devices, process parameters reflecting the emissions rates used for your low-risk demonstration, and stack height) must be submitted for incorporation as federally enforceable terms and conditions into your title V permit. You must submit an application for a significant permit modification to reopen your title V permit to incorporate such terms and conditions according to the procedures and schedules of 40 CFR part 71 or the EPA-approved program in effect under 40 CFR part 70, as applicable.

You must meet the requirements in table 2 to 40 CFR part 63, subpart DDDD, for each HAP control device used at the time when you completed your low-risk demonstration. You must monitor and collect data according to § 63.2270 of subpart DDDD to show continuous compliance with your control device operating requirements. You must demonstrate continuous compliance with the control device operating requirements that apply to you by collecting and recording the monitoring system data listed in table 2 to 40 CFR part 63, subpart DDDD for the process unit according to §§ 63.2269(a), (b), and (d) of subpart DDDD; and reducing the monitoring system data to the specified averages in units of the applicable requirement according to calculations in § 63.2270 of subpart DDDD; and maintaining the average operating parameter at or above the minimum, at or below the maximum, or within the range (whichever applies) established according to section 5(e) of this appendix.

(a) You must certify with each annual title V permit compliance certification that the basis for your affected source's low-risk determination has not changed. You must submit this certification to the permitting authority. You must consider the changes in paragraphs (a)(1) through (5) of this section.

(1) Process changes that increase HAP emissions, including, but not limited to, a production rate increase, an emission rate increase, a change in type of control device, changes in process parameters reflecting emissions rates used for your approved low-risk demonstration.

(2) Population shifts, such as if people move to a different location such that their risks from the affected source increase.

(3) Unit risk estimate increases posted on the EPA Web site (http://www.epa.gov/ttn/atw/toxsource/summary.html) for the pollutants included in table 1 to this appendix.

(4) Reference concentration changes posted on the EPA Web site (http://www.epa.gov/ttn/atw/toxsource/summary.html) for the pollutants included in table 1 to this appendix.

(5) Acute dose-response value for formaldehyde or acrolein changes.

(b) If your affected source commences operating outside of the low-risk subcategory, it is no longer part of the low-risk subcategory. You must be in compliance with 40 CFR part 63, subpart DDDD as specified in paragraphs (b)(1) through (3) of this section. Operating outside of the low-risk subcategory means that one of the changes listed in paragraphs (a)(1) through (5) of this section has occurred and that the change is inconsistent with your affected source's title V permit terms and conditions reflecting EPA's approval of the parameters used in your low-risk demonstration.

(1) You must notify the permitting authority as soon as you know, or could have reasonably known, that your affected source is or will be operating outside of the low-risk subcategory.

(2) You must be in compliance with the requirements of 40 CFR part 63, subpart DDDD as specified in paragraph (b)(2)(i) or (ii) of this section, whichever applies.

(i) If you are operating outside of the low-risk subcategory due to a change described in paragraph (a)(1) of this section, then you must comply with 40 CFR part 63, subpart DDDD beginning on the date when your affected source commences operating outside the low-risk subcategory.

(ii) If you are operating outside of the low-risk subcategory due to a change described in paragraphs (a)(2) through (5) of this section, then you must comply with 40 CFR part 63, subpart DDDD no later than 3 years from the date your affected source commences operating outside the low-risk subcategory.

(3)(i) You must conduct performance tests no later than 180 calendar days after the applicable date specified in paragraph (b)(2) of this section.

(ii) You must conduct initial compliance demonstrations that do not require performance tests 30 calendar days after the applicable date specified in paragraph (b)(2) of this section.

(iii) For the purposes of affected sources affected by this section, you must refer to the requirements in paragraph (b) of this section instead of the requirements of § 63.2233 when complying with 40 CFR part 63, subpart DDDD.

(a) You must keep records of the information used in developing the low-risk demonstration for your affected source, including all of the information specified in section 8 of this appendix.

(b) You must keep records demonstrating continuous compliance with the operating requirements for control devices.

(c) For each THC CEMS, you must keep the records specified in § 63.2282(c) of 40 CFR part 63, subpart DDDD.

The definitions in § 63.2292 of 40 CFR part 63, subpart DDDD, apply to this appendix. Additional definitions applicable for this appendix are as follows:

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 applying heat. An agricultural fiberboard mat dryer is a process unit.

Ancillary processes mean equipment and process units that are part of the PCWP affected source that are not defined elsewhere in this section or in section 63.2292 of subpart DDDD. Ancillary processes at a specific facility do not include the equipment and process units identified as insignificant sources of HAP emissions by that facility, and they do not include equipment and process units subject to another standard under 40 CFR part 63. Ancillary processes may be or may not be HAP emissions sources.

Ancillary processes are process units.

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.

Emission point means an individual stack or vent from a process unit that emits HAP required for inclusion in the low-risk demonstration specified in this appendix. Process units may have multiple emission points.

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 by applying heat to reduce the moisture content from stacked hardwood veneer. A hardwood veneer kiln is a process unit.

Hazard Index (HI) means the sum of more than one hazard quotient for multiple substances and/or multiple exposure pathways.

Hazard Quotient (HQ) means the ratio of the predicted media concentration of a pollutant to the media concentration at which no adverse effects are expected. For inhalation exposures, the HQ is calculated as the air concentration divided by the reference concentration (RfC).

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.

Look-up table analysis means a risk screening analysis based on comparing the toxicity-weighted HAP emission rate from the affected source to the maximum allowable toxicity-weighted HAP emission rates specified in tables 3 and 4 to this appendix.

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. The billet is cut into laminated strand lumber after exiting the press. An LSL press is a process unit.

LVL or PSL press means a composite wood product press that presses resinated stacks of veneers into a solid billet by application of heat and/or pressure. The billet is cut into laminated veneer lumber or parallel strand lumber after exiting the press. An LVL or PSL 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 to which heat is applied 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.

Reference Concentration (RfC) means an estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime. It can be derived from various types of human or animal data, with uncertainty factors generally applied to reflect limitations of the data used.

Resin storage tank means any storage tank, container, or vessel connected to plywood and composite wood product production that holds resin additives (in liquid form) containing any of the HAP listed in table 2A to this appendix. A resin storage tank is a process unit.

Rotary agricultural fiber dryer means a rotary dryer operated by applying heat 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 by applying heat 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.

Target organ specific hazard index (TOSHI) means the sum of hazard quotients for individual chemicals that affect the same organ or organ system (e.g., respiratory system, central nervous system).

Unit Risk Estimate (URE) means the upper-bound excess lifetime cancer risk estimated to result from continuous exposure to an agent at a concentration of 1 microgram per cubic meter (µgm/m3) in air.

Wastewater/process water operation means equipment that 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.

Worst-case operating conditions means operation of a process unit during emissions testing under the conditions that result in the highest HAP emissions or that result in the emissions stream composition (including HAP and non-HAP) that is most challenging for the control device if a control device is used. For example, worst case conditions could include operation of the process unit at maximum throughput, at its highest temperature, with the wood species mix likely to produce the most HAP, and/or with the resin formulation containing the greatest HAP.