7 Del. Admin. Code § 1127-3.0

Current through Register Vol. 28, No. 7, January 1, 2025

Section 1127-3.0 - Requirements for Existing and New Sources

3.1 For existing and new sources, the degree of limitation required of any source for control of any air contaminant shall not be affected by so much of any source's stack height that exceeds good engineering practice or by any other dispersion technique except as provided in 3.2.3 of this regulation. The "Guideline for Determination of Good Engineering Practice Stack Height", EPA-450/4-80-023R, June, 1985, provides guidance for determining good engineering practice heights.

3.2 Good Engineering Practice (GEP) stack height is the greater of:

3.2.1 A height of 65 meters, measured from the ground-level elevation at the base of the stack;

3.2.2

3.2.2.1 For stacks in existence on January 12, 1979, and for which the owner had obtained all applicable permits or approvals in accordance with these regulations, Hg = 2.5 H (see 3.2.2.2 for terms Hg and H), provided the owner or operator produces evidence that this equation was actually relied on in establishing an emission limitation;

3.2.2.2 For all other stacks, Hg = H + 1.5 L, where

Hg = good engineering practice 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;

L = lesser dimension (height or projected width) of nearby structure or structures,

provided that the Secretary may require the use of a field study or fluid model to verify GEP stack height for the source; or

3.2.3 The height demonstrated by a fluid model or a field study approved by the Secretary, 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, plume impactions or eddy effects created by the source itself, structures or terrain obstacles. "Guideline for Use of Fluid Modeling to Determine Good Engineering Practice Stack Height", July, 1981, EPA 450/4-81-003, and "Guideline for Fluid Modeling of Atmospheric Diffusion", April, 1981, EPA 600/8-81-009, shall be the basis for approval of fluid modeling demonstrations.

3.3 The provisions of 3.1 of this regulation shall not apply to

3.3.1 stack heights in existence or dispersion techniques implemented prior to December 31, 1970, except where pollutants are being emitted from such stacks or using such dispersion techniques by sources, as defined in 2.0 of 7 DE Admin. Code 1101, which were constructed, or reconstructed, or for which major modifications, as defined in 1.0 and 3.0 of 7 DE Admin. Code 1125, were carried out after December 31, 1970; or

3.3.2 coal-fired steam electric generating units subject to the provisions of Section 118 of the Clean Air Act, which commenced operation before July 1, 1957, and whose stacks were constructed under a construction contract awarded before February 8, 1974.

02/18/1987

7 Del. Admin. Code § 1127-3.0