Missouri Code of State Regulations
Title 10 - DEPARTMENT OF NATURAL RESOURCES
Division 10 - Air Conservation Commission
Chapter 6 - Air Quality Standards, Definitions, Sampling and Reference Methods and Air Pollution Control Regulations for the Entire State of Missouri
Section 10 CSR 10-6.140 - Restriction of Emissions Credit for Reduced Pollutant Concentrations From the Use of Dispersion Techniques

1. Stack heights on which construction commenced on before December 31, 1970, except where pollutants are being emitted from the stacks by source operations which were constructed, reconstructed, or on which major modifications were carried out after December 31, 1970; or

1. Began, or caused to begin, a continuous program of a actual on-site construction of the source, to be completed within reasonable time; or

2. Entered into binding agreements or contractual obligations, which cannot be canceled or modified without substantial loss to the owner or operator, to undertake a program of acconstruction of the source to be completed within a reason time.

1. Any technique designed to affect the concentration of a pollutant in the ambient air by-

2. This definition does not include: do

1. For installations seeking credit for reduced ambient pollutant concentrations from stack height exceeding that defined in paragraph (2)(E)2. of this rule, an excessive concentration is a maximum ground-level concentration due to emissions from a a stack due in whole or part to downwash, wakes, or eddy effects produced by nearby structures or nearby terrain features which a- are at least forty percent (40%) in excess of the maximum concentration experienced in the absence of the downwash, wakes, or eddy effects, and that contributes to a total concentration due to emissions from all installations that is greater than an ambient air quality standard. For installations subject to the prevention of significant deterioration program as set forth in 10 CSR 10-a 6.060(8), an excessive concentration means a maximum ground-level concentration due to emissions from a stack due to the same conditions as mentioned previously and is greater than a prevention of significant deterioration increment. The allowable emission rate to be used in making demonstrations under this definition shall be prescribed by the new source performance regulation as referenced by 10 CSR 10-6.070 for the source category unless the owner or operator demonstrates that this emission rate is infeasible. Where demonstrations are approved by the director, an alternative emission rate shall be established in consultation with the source owner or operator;

2. For installations seeking credit after October 11, 1983, for increases in stack heights up to the heights established under paragraph (2)(E)2. of this rule, an excessive concentration is either-

3. For installations seeking credit after January 12, 1979, for a stack height determined under paragraph (2)(E)2. of this rule where the director requires the use of a field study of fluid model to verify good engineering practice stack height, for installations seeking stack height credit after November 9, 1984, based on the aerodynamic influence of cooling towers, and for installations seeking stack height credit after December 31, 1970, based on the aerodynamic influence of structures not represented adequately by the equations in paragraph (2)(E)2. of this rule, a maximum groundlevel concentration due in whole or part to downwash, wakes, or eddy effects that is at least forty percent (40%) in excess of the maximum concentration experienced in the absence of downwash, wakes, or eddy effects.

1. Sixty-five meters (65 m) measured from the ground-level elevation at the base of the stack;

2. For stacks on which construction commenced on or before January 12, 1979, and for which the owner or operator had obtained all applicable permits or approvals required under 40 CFR 51 and 52, Hg = 2.5H provided the owner or operator produces evidence that this equation was actually relied on in establishing an emission limitation; and for all other stacks, Hg = H + 1.5L Where: Hg = GEP stack height, measured from the ground-level elevation at the base of the stack; H = height of nearby structure(s) measured from the ground-level elevation at the base of the stack; and L = lesser dimension, height, or projected width of the nearby structure(s). Provided that the director may require the use of a field study or fluid model to verify GEP stack height for the installation; or

3. The height demonstrated by a fluid model or field study approved by the director, which ensures that the emissions from a stack do not result in excessive concentrations of any air pollutant as a result of atmospheric downwash, wakes, or eddy effects created by the source itself, nearby structures, or nearby terrain features.

1. Routine maintenance, repair, and replacement of parts;

2. Use of an alternative fuel or raw material by reason of an order under sections 2(a) and (b) of the Energy Supply and Environmental Coordination Act of 1974, a prohibition under the Power Plant and Industrial Fuel Use Act of 1978, or by reason of a natural gas curtailment plan pursuant to the Federal Power Act;

3. Use of an alternative fuel or raw material, if prior to January 6, 1975, the source was capable of accommodating the fuel or material, unless the change would be prohibited under any enforceable permit condition which was established after January 6, 1975;

4. An increase in the hours of operation or in the production rate unless the change would be prohibited under any enforceable permit condition which was established after January 6, 1975; or

5. Use of an alternative fuel by reason of an order or rule under section 125 of the Clean Air Act.

1. For purposes of applying the formula provided in paragraph (2)(E)2. of this rule, nearby means that distance up to five (5) times the lesser of the height or the width dimension of a structure, but not greater than one-half (1/2) mile; and

2. For conducting fluid modeling or field study demonstrations under paragraph (2)(E)3. of this rule, nearby means not greater than one-half (1/2) mile, except that the portion of a terrain feature may be considered to be nearby which falls within a distance of up to ten (10) times the maximum height of the feature, not to exceed two (2) miles if feature achieves a height one-half (1/2) mile from the stack that is at least forty percent (40%) of the GEP stack height determined by the formula provided in paragraph (2)(E)2. of this rule, or twenty-six meters (26 m), whichever is greater, as measured from the ground-level elevation at the base of the stack. The height of the structure or terrain feature is measured from the ground-level elevation at the base of the stack.