06- 096 C.M.R. ch. 100, § 11

Current through 2024-51, December 18, 2024

Section 096-100-11 - Ambient increment

"Ambient increment" means, for new sources and modifications, the increase in ambient SO₂, PM_2.5, PM₁₀, and NO₂ concentrations of the future allowable emissions (the maximum emissions being modeled and licensed) over the baseline concentrations of these ambient air pollutants. For existing sources, "ambient increment" means the increase in ambient SO₂, PM_2.5, PM₁₀, and NO₂ concentrations of the actual current emissions over the baseline concentrations of these ambient air pollutants. To identify baseline emissions from a source for ambient increment determination, the Department shall presume actual emissions from the following calendar years to be representative of normal operation for the specified pollutants:

A. Calendar year 1977 for SO₂ and PM₁₀;

B. Calendar year 1987 for NO_2;

C. Calendar year 2010 for PM_2.5; and

D. For nonattainment areas, the calendar year the Department submits the regulation determination to EPA.

The Department may allow the use of a time period other than specified here if it is determined that the alternate time period is more representative of normal operation.

06- 096 C.M.R. ch. 100, § 11