Review of Existing Regulations

Regulations Which Lack Clarity Report

Bureau of Air Quality

February 28, 1996

INTRODUCTION


The Clean Air Act Amendments of 1990, considered to be the most complex and comprehensive environmental law ever considered by any Congress, not only set more specific pollution limits than the Clean Air Act Amendments of 1977, but included a series of rapid-fire dates by which states and regulated industries were required to implement pollution control measures in order to comply with these pollution limits. To meet these deadlines, the Department had to move rapidly on drafting and enacting new regulatory language. Some of the new Pennsylvania regulations were even finalized before the final Federal guidelines were published. Circumstances such as these have resulted in some regulations which were either not drafted in concise, clear language, or are too general in nature, which in turn have resulted in uncertainty, misinterpretation, and confusion. The Bureau of Air Quality therefore, in response to the August 4, 1995 "Regulatory Basics Initiative" memorandum from Secretary Seif, has reviewed Title 25, chapters 121 through 141, to determine which regulations lack clarity.

REGULATIONS


Chapter 121 General Provisions

Section 121.1 includes definitions of terms applicable to 25 PA Code Article III (Air Resources). Although these definitions are meant to clarify the key terms used throughout the regulations, some do not meet that objective and should be amended. These definitions are addressed as applicable within the discussions of each chapter.

Chapter 123 Standards For Contaminants

Fugitive Emissions

Section 123.1 states that no person may permit the emission of a fugitive air contaminant from any source other than those specified in Subsections 123.1(a)(1)-(8). This regulation requires zero emissions. Subsection 123.1(a)(9) allows the Department to exempt other sources and classes of sources, on a case-by-case basis, from this zero emission requirement, following a determination that fugitive emissions from the source, after appropriate control, are of minor significance with respect to causing air pollution and do not prevent or interfere with the attainment or maintenance of an ambient air quality standard. The concepts of "appropriate controls" and "minor significance" are neither defined nor spelled out in the regulation. This leads to inconsistent interpretations between and within the Regions when the field staff attempt to apply this rule.

Conclusion: The terms "appropriate control" and "minor significance" are not clear. Guidance from Central Office to all of the Regions addressing this issue should be developed. In addition, thorough training of all field staff across the state should be implemented regarding what are appropriate control measures for each source or class of sources; what constitutes emissions of minor significance; and what emissions affect which ambient air quality standard; or the terms "appropriate control" and "minor significance" need to be clearly defined in the regulation.

Odor Emissions

Section 123.31(b) prohibits the emission into the outdoor atmosphere of malodorous air contaminants in a manner such that the malodors are detectable outside the property of the person on whose land the source is being operated. Enforcement of this regulation is difficult because the definition of "malodor" in Section 121.1 is unclear and subjective. Department staff typically seek compliance by requiring the source owner to either install controls (Best Available Technology - "BAT") if appropriate, or to amend a process or an exhaust system to abate odors.

Conclusion: The definition of "malodor" in Section 121.1 should be changed to clarify what constitutes a malodor, based on recent legal precedent which has established criteria for what is a malodor. Section 123.31 should be amended to clarify what the responsibility is of the source owner and limit the control to BAT. These two changes would clarify and simplify the enforcement aspects of the regulation.

Chapter 127 Construction, Modification, Reactivation and Operation of Sources

This chapter includes the requirements for permitting of air contamination sources which range from general plan approvals and operating permits through Prevention of Significant Deterioration of air quality (PSD), Emission Reduction Credits (ERCs), New Source Review (NSR), and Title V operating permits. Several inconsistencies and ambiguities exist throughout the breadth of this set of regulations, which are causing difficulties in interpreting and applying these rules. Although Chapter 127 is cumbersome, some readily apparent examples of such inconsistencies and ambiguities follow.

Subchapter A General

"Best available technology" is defined in Section 121.1 as "Equipment, devices, methods or techniques as determined by the Department which will prevent, reduce or control emissions of air contaminants to the maximum degree possible and which are available or may be made available." This term is used at Section 127.1 which requires new air contamination sources to "control the emission of air pollutants to the maximum extent, consistent with the best available technology as determined by the Department as of the date of issuance of the plan approval for the new source." This requirement has been in existence since July 1972. Since its promulgation, the Department has provided best available technology guidance for only a handful of the infinite number of different types of air contamination sources. This results in a vast majority of situations where best available technology determinations are made on a case-by-case basis. This, in turn, has led to inconsistencies from Region to Region and case to case.

Conclusion: Best available technology guidance documents need to be developed for more sources. These documents should include the impact of economic and social constraints. The Technical Support Section needs to be more involved in the determinations being made to ensure more consistency between the regions.

Subchapter B Plan Approval Requirements

Subsections 127.11(a) (Plan approval requirements for reactivation of sources) and 127.215 (Reactivation under Subchapter E. New Source Review) are inconsistent with each other. Subsection 127.11(a) requires a reactivation plan to be submitted at least 60 days before reactivation, while Subsection 127.215 requires a reactivation plan to be submitted 30 days before reactivation. Subsection 127.215 requires the Department to act on the reactivation plan within 30 days, while Subsection 127.11(a) does not contain any such requirement. Also, if one takes the strict interpretation of Subsection 127.215, this requirement allows a deactivated source to be reactivated only during the term of its permit. Once the permit expires, the deactivated source cannot be reactivated under the provisions of Subsection 127.215.

Conclusion: Make the requirements of Subsections 127.11(a) and 127.215 consistent.

Section 127.14 addresses types of air contamination sources which are exempt from the plan approval and operating permit requirements, including in Subsection 127.14(a)(9): "Physical changes to sources when the Department has determined the physical changes to be of minor significance." A source, however, must submit a "Request for Determination for the Need of Plan Approval" before a determination can be made whether a plan approval is needed or not. These determinations are made on a case by case basis which has resulted in inconsistencies between Regions.

Conclusion: More information is needed on what types of sources are exempt from the plan approval process. The program maintains a listing of such sources which needs to be updated and expanded to include all of the sources which have received exemptions from the Department. If this is not feasible, consideration should be given to specifying an amount in pounds per day of any single non-toxic air pollutant below which a source would be exempt. Clarification is also needed on what physical changes are considered to be of minor significance in order to promote consistent compliance and enforcement statewide. This could be done through guidance from Central Office to the Regions, or by providing a regulatory definition of the term "minor significance".

Subchapter E New Source Review

Subsection 127.202(a) states the special permit requirements in this subchapter apply to a facility submitting a complete plan approval application to the Department after January 15, 1994. New sources which are being constructed now or are in the planning stages of construction must meet a set of very stringent requirements if NSR is applicable to such installations. Meeting these requirements is not easy even for a new source. A strict interpretation of this Subsection requires that sources illegally constructed prior to January 15, 1994 which submit plan approvals after January 15, 1994, be subjected to the same standards (in this case NSR) as new sources constructed since January 15, 1994 or still in the planning stages. Is this the intent of this regulation?

Conclusion: Change Subsection 127.202(a) to clearly state that it applies only to new source construction and modification that actually occurs after January 15, 1994. Sources constructed prior to January 15, 1994 should be subject to the requirements that were in effect at the time of construction.

Clarification is needed on the interpretation in several subsections, including 127.203(b) and (c), 127.204, and 127.211, of the language "increase in the potential to emit". Increase over what? Previous potential to emit? Previous actual emissions? 1990 baseline? Major source threshold? Major source limits?

Conclusion: The phrase "increase in the potential to emit" needs to be clearly defined.

Sections 127.206-209 pertain to the general requirements, generation, use, and registration of Emission Reduction Credits (ERCs). These regulations are extremely unclear on the differences between emission reductions for netting purposes, ERCs for internal credits, and ERCs for external credits. Explicit regulatory language or policy guidance for the field staff is needed to understand and implement the many nuances of ERCs. For example, Subsection 127.208(5) allows interstate ERC trades only upon approval by PA and the other state through SIP approved rules and procedures including an EPA SIP revision. Does this mean that each and every interstate ERC trade must be approved by a SIP revision? In addition, the process of registering emission reduction credits, particularly from nonmajor sources, needs to be clarified by making the procedures less burdensome and time- consuming.

Conclusion: Sections 127.206-209 need to be rewritten.

Section 121.1 does not include definitions of the terms "actual emissions" and "allowable emissions". EPA's New Source Review regulations require State Implementation Plans to include numerous definitions, including definitions of "actual emissions" and "allowable emissions". These terms are used in Subchapter E, New Source Review, at Section 127.207, which defines how ERCs are generated and created. With no definitions of these terms provided in Section 121.1, confusion results on what these terms mean, especially when attempting to apply the definitions cited at 40 CFR 51.165(a)(1)(xi) and 40 CFR 51.165(a)(1)(xii).

Conclusion: Definitions for "actual emissions" and "allowable emissions" should be included in Chapter 121 of Title 25. These definitions should be clear, concise, and simply written so that room for interpretation is minimized.

"Major modification" and "modification" as defined in Section 121.1 are inconsistent. The definition of "major modification" excludes: "...routine repairs, maintenance and a change in the hours of operation or an increase in the rate of production unless prohibited by a permit condition.", but does not specifically exclude a replacement. In contrast, the Section 121.1 definition of "modification" excludes replacement but does not exclude: "...a change in the hours of operation/increase in the rate of production unless prohibited by a permit condition." This inconsistency leads to misinterpretation about what constitutes a modification and what does not.

Conclusion: The definitions of "major modification" and "modification" are inconsistent. Revise these definitions to conform to EPA's definitions of each which are found at 40 CFR 51.165(a)(1)(v), 51.166(b)(2)(iii) and 60.14(e). All exceptions contained in the EPA definitions should be included in both the definition of "major modification" and "modification". As part of this definition, the term "replacement" must also be clearly defined so as to prevent such "replacements" as an old utility boiler being replaced by a new utility boiler without plan approval.

Another issue which needs to be addressed in the definition of "modification" is the Department's policy whereby if the cost of the changes or modifications being proposed for an existing air contamination source or process equals or exceeds 50% of the cost of a new unit, a modification will occur.

Conclusion: This clarification should be included in the definition of "modification".

A third area under this category deals with the utilities' request for an exemption from the definition of "major modification" of a "pollution control project" at an electric utility. Providing for such an exemption would exclude these projects from the New Source Review requirements. Presently, this exemption does not exist in the definition of major modification at Section 121.1 nor does Section 121.1 define a "pollution control project". Although this issue does not pose a problem of clarity, it could result in a ticklish situation. For example, a utility may undertake a "pollution control project" in order to minimize the emissions of NOx. In so doing, the project results in an increase of VOC emissions which triggers the applicability of the New Source Review regulations. The amount of NOx reductions dwarfs the VOC increase but with the definition of "major modification" as presently written, this project becomes subject to NSR.

Conclusion: Because the definition of "major modification" found at 40 CFR 51.165(a)(1)(xxv) includes far more than the example cited above, the impact of adopting EPA's definition of "pollution control project" and exempting such projects from New Source Review should be given thoughtful and thorough consideration before doing such. As far as the example cited above, such situations should be exempted from New Source Review and the regulations should be rewritten to accommodate them.

Subchapter F Operating Permit Requirements

Section 127.449 is unclear as to the type of emission that is referred to for de minimis increases. Does the de minimis emission increase refer to actual, allowable, or potential emissions?

Conclusion: Clarification is needed on which type of emission is referred to under de minimis emission increases.

Subchapter G Title V Operating Permits

If a Title V source names its acid rain designated representative as the "responsible official", the Department's definition of "responsible official" allows the designated representative of an acid rain affected source to serve as the responsible official for other purposes under the regulatory requirements for the Title V program. However, a designated representative is not allowed to serve as the responsible official for the Department's state only plan approval and operating permit program.

Conclusion: The definition of "responsible official" should be changed to allow the designated representative to serve as the responsible official for state only requirements.
Overall Chapter Conclusion: Chapter 127 as a whole needs a complete rewrite. Subchapter E (NSR) in particular is poorly written and difficult to understand and interpret; Subchapter E is, however, closely based on the EPA regulations found at 40 CFR 51.165, and the interpretive ruling found at 40 CFR Part 51, Appendix S. The EPA is currently revising the Federal NSR rules. When the Federal rules are finalized, the Department should review and amend Pennsylvania's NSR regulations as necessary and appropriate.. The other comments above should also be addressed when revisions to Chapter 127 are crafted. Concise and explicit language should be used.

Chapter 129 Standards for Sources

Miscellaneous Sources

Different programs within the Department address or impact open burning operations. The requirements differ between the programs, which creates confusion about whether open burning is allowed or not.

The Air Quality regulations at 25 PA Code Section 129.14 prohibit open burning in Air Basins (129.14(a)). Open burning is allowed in areas outside of the Air Basins provided that the smoke and odors from the burning are not detectable outside of the property on which the burning is occurring (129.14(b)). Enforcement of the property line provision is extremely difficult in rural areas. A list of exceptions to the property line limitation contained in Subsection 129.14(b) are provided at Subsection 129.14(c). All of the exceptions have been used at one time or another by the regulated community to escape prosecution under Subsection 129.14(b). These exceptions add to the confusion as to what can be burned and where. Subsections 129.14(c)(4) pertaining to fires set in conjunction with the production of agricultural commodities; - (5) fires set for the purpose of burning domestic refuse; and - (6) fires set for recreational and ceremonial purposes are the exceptions most often misinterpreted, resulting in numerous fires about which the Air Quality Program receives complaints. Upon investigation, it is found that the person doing the burning is burning items which should not be burned but because the situation may fall under an exception, the field inspector exercises enforcement discretion and dismisses the event. Staff time, in turn, is wasted, the burning continues, and public dissatisfaction continues.

Conversely, the Solid Waste Management Act (Act 97) prohibits the burning of waste without a permit from the Department (35 P.S. Section 6018.610(3)). The Department does not issue permits for open burning operations; open burning therefore is banned under the Solid Waste Management Act.

The Bureau of Mining and Reclamation's regulation at 25 PA Code Section 211.61(cc) impacts open burning issues also. This regulation requires that the wood, paper, and fiber materials used to wrap explosives shall be burned in an isolated area after the blast has been fired. This situation is not addressed in the Air Resources regulations, thereby creating confusion.

Conclusion: The scope of this regulation and staff enforcement time should be restricted to those activities which have significant air quality impacts, such as industrial wastes, tires, demolition wastes, and other large scale activities. Two different ways to address the inconsistencies between the Solid Waste Management Act (35 P.S. 6018.610(3)) and 25 PA Code Section 129 are: a) rewrite one to coincide with the other, preferably rewriting or even deleting 129.14 to coincide with the Solid Waste Management Act; or b) Subsections 129.14(c)(4), -(5), -(6), and -(7) could be deleted from the Air Resources Rules and Regulations. The emissions and odors from open burning of domestic refuse and agricultural wastes, ceremonial fires, cookout fires, and other such activities are more of a local nuisance problem than an air pollution problem. Subsection 129.14(b) could be amended to: 1) restrict open burning to these categories only (domestic refuse, agricultural wastes, ceremonial fires, and cookout fires), within the limits which currently exist at Subsections 129.(b)(1)-(5); and 2) delegate the regulation of such open burning operations to the municipality in which the burning is taking place, under the authority of Section 12 of the Air Pollution Control Act (35 P.S. 4012). The local municipalities could then address these situations in accordance with the restrictions set at 129.14(b(1)-(5). Subsections 129.14(c)(1), -(2), and -(3) may remain as currently stated. Subsection 129.14(d), which addresses clearing and grubbing wastes, should be amended to require that such wastes be composted or chipped and spread for mulch, rather than burned. Section 121.1 should be amended to include definitions for domestic refuse and clearing and grubbing wastes, and to incorporate the various waste definitions which are defined in the hazardous waste, municipal waste, and residual waste regulations of Title 25. Including these definitions will clarify and simplify the enforcement of open burning regulations. Section 129.14 should also be amended to provide an exemption for the burning of explosive wastes in accordance with mining regulation Subsection 211.61(cc). The Solid Waste Management Act could be amended to coincide with these provisions of the Air Resources regulations. Due to the impact and scope of such changes, a careful review and evaluation of any proposed changes is needed before making a final decision on how to resolve this problem.

SOURCES OF VOCs

Subsection 129.52(a) applies to all surface coating processes, regardless of the size of the facility, which emit or have emitted VOCs into the outdoor atmosphere in quantities greater than 3 pounds per hour, 15 pounds per day or 2.7 tons per year during any calendar year since January 1, 1987. With such a low applicability trigger, the regulations have been extended to a number of operators which, as a group, emit a very small percentage of the total overall VOC emissions, which in turn has little impact on the environment relative to ozone. Also, if an operator triggers the applicability level any time after January 1, 1987, he must continue to use compliant coatings even if subsequent emissions drop under these thresholds. Is it necessary to concern ourselves with such small sources?

NB In the document pertaining to regulations with significant noncompliance, the statement is made that "Our permitting guidelines generally exempt VOC sources below 10 tons per year". This is somewhat misleading. If the new source of VOCs is one which: a) is not covered by Table I of Section 129.52, b) is part of a facility whose total VOC emissions are less than 25 tons per year, and c) has emissions of less than 10 tons per year, then the new source is exempt from the plan approval requirements. If the new VOC source is one which is covered by Table I of Section 129.52, then the plan approval requirements apply if the new source's VOC emissions are greater than 3 pounds per hour, 15 pounds per day, or 2.7 tons per year.

Conclusion: The applicability threshold of 3 pounds per hour, 15 pounds per day, or 2.7 tons per year should be rethought. While this requirement is a direct result of Federal requirements, consideration should be given to reinstating the 50 ton per year threshold for attainment areas, or other ways of satisfying the Federal requirements should be explored in order to make an appropriate change to the regulation.

Subsection 129.52(b)(1) creates confusion about what constitutes compliance. To evaluate compliance, a coating user must compare the weight of VOCs per gallon of coating (minus water) of the coating being used to the applicable limit contained in Table I of Subsection 129.52(b)(1), after adjustment to a standard solvent density of 7.36 pounds per gallon and to a solids basis. Program staff do not fully understand the application of these requirements, let alone the coating user. How does one account for water? What use does one make of the standard solvent density of 7.36 pounds per gallon? The solvent density adjustment and solids basis requirements have complicated the procedure for determining compliance. Furthermore, Section 129.52 makes no mention of exempt solvents, but EPA guidance discusses both water and exempt solvents. Can the field staff account for exempt solvents within the scope of Section 129.52 as currently written? Last but not least, independent evaluation of compliance is difficult, if not impossible, to achieve since EPA Reference Method 24 (found at 40 CFR 60 Appendix A) does not include an independent analytical test to determine the volume percent of solids in the coating, which piece of data is required in order to evaluate compliance of a coating on a pounds of VOC per gallon of solids basis.

Conclusion: Subsections 129.52(b)(1) and -(2) should be amended to clearly explain how to account for both water and exempt solvents contained in coatings. The calculations which must be used to account for the water and exempt solvents should be spelled out in the regulation or provided in guidance to the field staff. The standard solvent density adjustment and solids basis requirements should be deleted, if possible, from the regulation. If it is not possible to delete these two requirements, then: 1) the calculations needed to convert coatings to a "solids" basis should be spelled out in the regulation or in guidance; 2) Table I should be amended to include the solids-based limits (pounds of VOC per gallon of solids), using the standard solvent density of 7.36 pounds of VOC per gallon of VOC required by EPA; and 3) an analytical method should be found for the DEP laboratory to use to independently determine the volume solids of a coating sample. Doing 1 and 2 would eliminate much of the confusion now shared by field staff and regulated industry; doing 3 would eliminate reliance on company-supplied data and provide independent evaluation of coating compliance.

Although Section 129.52 is legally applicable to all types of surface coating application techniques, the regulations make no provision for the differences in transfer efficiencies inherent in the different techniques. Field staff therefore do not know how to apply this section to situations where transfer efficiency should be included as part of the compliance evaluation. As a result, enforcement of the current regulations discriminates against the more efficient application methods. Dip coating, for example, is more efficient than spray coating and usually generates lower VOC emissions, even if additional thinner must be added to the diptank to maintain proper viscosity of the coating. For example, a metal furniture operation could purchase and use a coating that has 3.00 pounds of VOC per gallon of coating (minus water). This coating, as purchased, meets the Table I limit of 3.00 pounds of VOC per gallon of coating (minus water). One hundred gallons of this coating could then be put into a diptank. To bring this coating up to the proper dipping viscosity, however, one must add some thinner, and fifty gallons of a typical thinner are added to the diptank. The addition of the thinner now brings the coating in the diptank (as applied) to a value of 4.42 pounds of VOC per gallon of coating (minus water), which exceeds the Table I limit of 3.00 pounds of VOC per gallon of coating (minus water). The coating therefore is now considered to be out of compliance. The amount of coating solids transferred to the metal furniture from this coating mixture is 47.7 gallons and the total VOC emissions from using this 150 gallons of coating and thinner are 662.5 pounds of VOC. Alternatively, this coating could be applied, as purchased, to the metal furniture using a spray coating technique. Because spray coating is a less efficient method than dip coating, one must use more coating to achieve the same amount of solids applied. To apply 47.7 pounds of solids when spraying this coating, one must use 360 gallons of the coating. The total VOC emissions arising from the spray application of this amount of coating is 1080 pounds of VOC. So although the coating in the diptank is technically out of compliance when compared to the appropriate Table I limit (because of the additional thinner), the VOC emissions from the dip operation are almost half the VOC emissions from the spray operation using the same coating, because the spray application method is much less efficient. The spray operation is considered to be in compliance with Table I, however, because the coating is used in the "as purchased" state, which complies with Table I. Therefore the company which fulfills the overall intent of the Department's goal of reducing atmospheric emissions of VOC is penalized because of the inadequacies of the regulation with respect to transfer efficiency, while the company which complies with the regulation is actually creating more emissions.

Conclusion: Section 129.52 should be amended to account for differences in transfer efficiency between different coating application methods. New Jersey provides in the New Jersey Administrative Code, Title 7, Chapter 27, Subchapter 16, at Section 7:27-16.7(f) and Table 7C, for alternative compliance by automobile and light duty truck surface coaters (who use a variety of spray coating methods) based on the differences in transfer efficiency. This language could perhaps serve as a example for Pennsylvania in creating an amendment which allows for alternative compliance due to the differences in transfer efficiency between different coating application methods.

Table I of Subsection 129.52(b)(1) includes automobile and light duty truck coating. Item 6(c) of Table I provides an emissions limit for repair coatings used in automobile and light duty truck coating operations. It is possible to construe that refinishing, repair coating, and customized top coating of vehicles at small facilities such as autobody shops is covered by this requirement. The definition of "miscellaneous metal parts" at 25 PA Code Section 121.1, however, specifically exempts refinishing and customized top coating of automobiles and trucks if production does not exceed 34 vehicles per day.

Conclusion: Section 129.52 should be amended to provide an exemption for low-usage facilities such as autobody shops. The states of Michigan and New Jersey provide such exemptions in their air program regulations, which could serve as guides for amending Pennsylvania's regulation.

Subsection 129.52(c) pertains to record keeping. The existing regulations are vague and foster inconsistency between permits because the permit writers define the record keeping requirements on a case by case basis.

Conclusion: The record keeping requirements need to be simplified and revised so that only the minimum amount of data needed to demonstrate compliance is required.

"Miscellaneous metal parts and products" is defined broadly at Section 121.1, which leads to a variety of interpretations. As written, the definition has been interpreted to include everything constructed of metal except for those metal parts listed separately in Table I of Section 129.52 (those categories in Table I separate from miscellaneous metal parts). A more appropriate definition would include only those items listed in the current definition, including those found under the SIC Codes cited.

Conclusion: As written, the definition of "miscellaneous metal parts" is overly broad. An easy correction would be to delete the phrase "but not limited to" from line 2 of the definition.

"Semitransparent wiping and glazing stains" and "semitransparent spray stains" are included in the definitions of Section 121.1. However, these wood furniture and cabinet coatings are no longer regulated under Section 129.52, having been deleted from Table I several years ago. Such coatings contain no solids, so compliance is undefined. If the history of these stains is not known, it is possible that their use as either wipe, spray, spatter, or pad stains may be lumped in with "all other coatings" which are regulated under Table I, item 11, of Section 129.52. When stains and toners were deleted from item 11 of Table I, however, this was done for the purpose of deregulating them.

Conclusion: The Department's intent is not to regulate stains and toners. A statement explaining that "semitransparent wiping and glazing stains" and "semitransparent spray stains" are not regulated should be added to the regulations.

The Chapter 121.1 definitions that address wood cabinet and furniture coatings (clear coat, wash coat, final repair coat, opaque ground coats and enamels, and clear sealers) need clarification and revision. Presently, as defined, these coatings are subject to different interpretations. For example, a wood furniture manufacturer uses several coatings that the company considers "stains", the coating manufacturer considers "clear tone enamels", and the Department considers "opaque ground coats and enamels" because the coating completely hides the color of the substrate in a single coat, whereas a "stain" does not. By calling the coatings "stains", however, the wood furniture manufacturer escapes regulation since stains are no longer regulated under Table I, item 11, of Section 129.52.

Conclusion: The definitions alluded to above should contain parameters such as minimum percent solids by weight to clarify the regulation. The definitions of all wood cabinet and furniture coatings should conform to the definitions advocated by the Wood Cabinet and Furniture Manufacturers Association.

Chapter 139 Sampling and Testing

Subchapter C Requirements For Continuous In-Stack Monitoring For Stationary Sources

The General Requirements, Section 139.101, addresses data availability for Continuous Emission Monitoring Systems (CEMS). Subsection 139.101(12) states in part "...For purposes of calculating data availability, "process down" time, as specified in the manual referenced in Subsection 139.102(3), shall be considered valid time." Subsection 139.101(12)(ii) states "In each calendar quarter, at least 95% of the hours during which the monitored source is operating shall be valid as set forth in the quality assurance section of the manual referenced in Subsection 139.102(3)." This subsection can be misconstrued to mean that if a source only operates two hours during a quarter and has invalid data for one hour, the source is in violation of Subsection 139.101(12)(ii).

Conclusion: Subsection 139.101(12)(ii) should be rewritten to read "In each calendar quarter at least 95% of the hours during which a source is monitored, including "process down" time, shall be valid as set forth in the quality assurance section of the manual referenced in Subsection 139.102(3)."