c) Either documentation of customer specifications requiring higher values or documentation that the desired properties of the product make necessary for RSi to exceed 6% by weight of the liquid VOC applied and that such properties cannot be achieved by other means.

NR 440.74(4)(a)3.f.f. The point at which Mr is to be measured shall be established when the compliance procedures are approved. The presumptive point of measurement shall be prior to separation/purification; a point after separation/purification may be adopted for enhanced convenience or accuracy.

NR 440.74(4)(a)4.4. Short-term liquid material balance. This method may be used as an alternative to the monthly liquid material balance described in subd. 3. The owner or operator using this method shall comply with the following procedures to determine VOC emission reduction for a 3 to 7 day period and shall continuously monitor VOC emissions as specified in sub. (5).

NR 440.74(4)(a)4.a.a. Use the procedures described in subd. 3. a. through f. to determine the overall emission reduction, R. Compliance is demonstrated if the value of R is equal to or greater than 0.90.

NR 440.74(4)(a)4.b.b. The number of days for the performance test is to be based on the affected facility’s representative performance consistent with the requirements of s. NR 440.08 (3). Data demonstrating that the chosen test period is representative shall be submitted to the department for approval.

NR 440.74(4)(b)(b) Each owner or operator of an affected coating operation subject to the standard specified in sub. (3) (b) 2. shall:

NR 440.74(4)(b)1.1. Demonstrate that a total enclosure is installed. The total enclosure shall either be approved by the department in accordance with the provisions of 40 CFR 60.746 or meet the requirements in subd. 1. a. to f. as follows:

NR 440.74(4)(b)1.a.a. The only openings in the enclosure are forced makeup air and exhaust ducts and natural draft openings such as those through which raw materials enter and exit the coating operation;

NR 440.74(4)(b)1.b.b. Total area of all natural draft openings does not exceed 5% of the total surface are of the total enclosure’s walls, floor and ceiling;

NR 440.74(4)(b)1.c.c. All access doors and windows are closed during normal operation of the enclosed coating operation, except for brief, occasional openings to accommodate process equipment adjustments. If openings are frequent or if the access door or window remains open for a significant amount of time during the process operation, it shall be considered a natural draft opening. Access doors used routinely by workers to enter and exit the enclosed area shall be equipped with automatic closure devices;

NR 440.74(4)(b)1.d.d. Average inward face velocity (FV) across all natural draft openings is a minimum of 3,600 meters per hour as determined by the following procedures:

1) Construct all forced makeup air ducts and all exhaust ducts so that the volumetric flow rate in each can be accurately determined by the test methods and procedures specified in sub. (6) (c) and (d). Volumetric flow rates shall be calculated without the adjustment normally made for moisture content; and

NR 440.74(4)(b)1.e.e. The air passing through all natural draft openings flows into the enclosure continuously. If FV is less than or equal to 9,000 meters per hour, the continuous inward airflow shall be verified by continuous observation using smoke tubes, streamers, tracer gases or other means approved by the department over the period that the volumetric flow rate tests required to determine FV are carried out. If FV is greater than 9,000 meters per hour, the direction of airflow through the natural draft openings shall be presumed to be inward at all times without verification.

NR 440.74(4)(b)1.f.f. All sources of emissions within the enclosure shall be a minimum of 4 equivalent diameters away from each natural draft opening.

NR 440.74(4)(b)2.2. Determine the control device efficiency using Equation (1) or Equations (3) and (4), as applicable and the test methods and procedures specified in sub. (6) (b) to (g).

NR 440.74(4)(b)3.3. Compliance is demonstrated if the installation of a total enclosure is demonstrated and the value of E determined from Equation (1) or the value of Hsys determined from Equations (3) and (4), as applicable, is equal to or greater than 0.95.

NR 440.74(4)(c)(c) To demonstrate compliance with sub. (3) (c) 1., standard for coating mix preparation equipment servicing a coating operation with concurrent construction of a control device that uses at least 130 Mg per year of VOC, each owner or operator of affected coating mix preparation equipment shall demonstrate that:

NR 440.74(4)(c)1.a.a. Cover shall be closed at all times except when adding ingredients, withdrawing samples, transferring the contents or making visual inspection when such activities cannot be carried out with cover in place. Activities shall be carried out through ports of the minimum practical size;

NR 440.74(4)(c)1.b.b. Cover shall extend at least 2 centimeters beyond the outer rim of the opening or shall be attached to the rim;

NR 440.74(4)(c)1.c.c. Cover shall be of such design and construction that contact is maintained between cover and rim along the entire perimeter;

NR 440.74(4)(c)1.d.d. Any breach in the cover, such as a slit for insertion of a mixer shaft or port for addition of ingredients, shall be covered consistent with subd. 1. a. to c. when not actively in use. An opening sufficient to allow safe clearance for a mixer shaft is acceptable during those periods when the shaft is in place; and

NR 440.74(4)(c)1.e.e. A polyethylene or nonpermanent cover may be used provided it meets the requirements of subd. 1. b. to d. A cover may not be reused after once being removed.

NR 440.74(4)(c)2.2. Procedures detailing the proper use of covers, as specified in subd. 1. a., have been posted in all areas where affected coatings mix preparations equipment is used;

NR 440.74(4)(c)3.3. The coating mix preparation equipment is vented to a control device while preparation of the coating is taking place within the vessel; and

NR 440.74(4)(c)4.4. The control device efficiency, E or Hsys as applicable, determined using Equation (1) or Equations (3) and (4), respectively and the test methods and procedures specified in sub. (6) (b) to (g) is equal to or greater than 0.95.