(a) Compliance using the emissions averaging option is demonstrated on a 12-month rolling-average basis and is determined at the end of every month (12 times per year). The first 12-month rolling-average period begins on the compliance date specified in § 63.5695.

(b) At the end of the twelfth month after your compliance date and at the end of every subsequent month, use equation 1 of this section to demonstrate that the organic HAP emissions from those operations included in the average do not exceed the emission limit in § 63.5698 calculated for the same 12-month period. (Include terms in equation 1 of § 63.5698 and equation 1 of this section for only those operations and materials included in the average.)

$$ Where: HAP emissions= Organic HAP emissions calculated using MACT model point values for each operation included in the average, kilograms. PVR = Weighted-average MACT model point value for production resin used in the past 12 months, kilograms per megagram. MR = Mass of production resin used in the past 12 months, megagrams. PVPG = Weighted-average MACT model point value for pigmented gel coat used in the past 12 months, kilograms per megagram. MPG = Mass of pigmented gel coat used in the past 12 months, megagrams. PVCG = Weighted-average MACT model point value for clear gel coat used in the past 12 months, kilograms per megagram. MCG = Mass of clear gel coat used in the past 12 months, megagrams. PVTR = Weighted-average MACT model point value for tooling resin used in the past 12 months, kilograms per megagram. MTR = Mass of tooling resin used in the past 12 months, megagrams. PVTG = Weighted-average MACT model point value for tooling gel coat used in the past 12 months, kilograms per megagram. MTG = Mass of tooling gel coat used in the past 12 months, megagrams.

(c) At the end of every month, use equation 2 of this section to compute the weighted-average MACT model point value for each open molding resin and gel coat operation included in the average.

$$ Where: PVOP = weighted-average MACT model point value for each open molding operation (PVR, PVPG, PVCG, PVTR, and PVTG) included in the average, kilograms of HAP per megagram of material applied. Mi = mass of resin or gel coat i used within an operation in the past 12 months, megagrams. n = number of different open molding resins and gel coats used within an operation in the past 12 months. PVi = the MACT model point value for resin or gel coat i used within an operation in the past 12 months, kilograms of HAP per megagram of material applied.

(d) You must use the equations in Table 3 to this subpart to calculate the MACT model point value (PVi) for each resin and gel coat used in each operation in the past 12 months.

(e) If the organic HAP emissions, as calculated in paragraph (b) of this section, are less than the organic HAP limit calculated in § 63.5698(b) for the same 12-month period, then you are in compliance with the emission limit in § 63.5698 for those operations and materials included in the average.

[66 FR 44232, Aug. 22, 2001; 66 FR 50504, Oct. 3, 2001]