reasonable grounds to dispute the results obtained by an alternative method, he may require the use of a reference method. If the results of the reference and alternative methods do not agree, the results obtained by the reference method prevail, and the Administrator may notify the owner or operator that approval of the method previously considered to be alternative is withdrawn. Whenever Method 107 is specified, and the conditions in Section 1.2, "Applicability" of Method 107A are met, Method 107A may be used. (1) Method 106 is to be used to determine the vinyl chloride emissions from any source for which an emission limit is prescribed in § 61.62(a) or (b), § 61.63(a), or §61.64(a)(1), (b), (c), or (d), or from any control system to which reactor emissions are required to be ducted in §61.64(a)(2) or to which fugitive emissions are required to be ducted in §61.65(b)(1)(ii), (b)(2), (b)(5), (b)(6)(ii), or (b)(9)(ii). (i) For each run, one sample is to be collected. The sampling site is to be at least two stack or duct diameters downstream and one half diameter upstream from any flow disturbance such as a bend, expansion, contraction, or visible flame. For a rectangular cross section, an equivalent diameter is to be determined from the following equation: 2(length)(width)/(length + width) The sampling point in the duct is to be at the centroid of the cross section. The sample is to be extracted at a rate proportional to the gas velocity at the sampling point. The sample is to contain a minimum volume of 50 liters (1.8 ft3) corrected to standard conditions and is to be taken over a period as close to 1 hour as practicable. (ii) Each emission test is to consist of three runs. For the purpose of determining emissions, the average of results of all runs is to apply. The average is to be computed on a time weighted basis. (iii) For gas streams containing more that 10 percent oxygen, the concentration of vinyl chloride as determined by Method 106 is to be corrected to 10 percent oxygen (dry basis) for determina tion of emissions by using the following equation: Cb(corrected)=Cb (10.9)/(20.9-percent O2) Where: Cb(corrected) The concentration of vinyl chloride in the exhaust gases, corrected to 10 percent oxygen. Cb The concentration of vinyl chloride as measured by Method 106. 20.9 Percent oxygen in the ambient air at standard conditions. 10.9 Percent oxygen in the ambient air at standard conditions, minus the 10.0 percent oxygen to which the correction is being made. Percent O2 = Percent oxygen in the exhaust gas as measured by Method 3 of appendix A of part 60 of this chapter. (iv) For those emission sources where the emission limit is prescribed in terms of mass rather than concentration, mass emissions are to be determined using the following equation: = Concentration of vinyl chloride as measured by Test Method 106, ppmv. Dvc Density of vinyl chloride at standard conditions, 2.60 kg/m3 (0.162 lb/ft3). Q = = Volumetric flow rate as determined by Method 2 of appendix A to part 60 of this chapter, m3/hr (ft3/hr). K = Unit conversion factor, 1,000 g/kg (1 lb/ lb). 10-6 = Conversion factor for ppm. Z Production rate, kg/hr (lb/hr). (2) Method 107 or Method 601 (incorporated by reference as specified in § 61.18) is to be used to determine the concentration of vinyl chloride in each inprocess wastewater stream for which an emission limit is prescribed in § 61.65(b)(9)(i). (3) When a stripping operation is used to attain the emission limits in § 61.64(e) and (f), emissions are to be determined using Method 107 as follows: (i) The number of strippers (or reactors used as strippers) and samples and the types and grades of resin to be sampled are to be determined by the Administrator for each individual plant at the time of the test based on the plant's operation. (ii) Each sample is to be taken immediately following the stripping operation. (iii) The corresponding quantity of material processed by each stripper (or reactor used as a stripper) is to be determined on a dry solids basis and by a method submitted to and approved by the Administrator. (iv) At the prior request of the Administrator, the owner or operator shall provide duplicates of the samples required in paragraph (g)(3)(i) of this section. (4) Where control technology other than or in addition to a stripping operation is used to attain the emission limit in §61.64(e), emissions are to be determined as follows: (i) Method 106 is to be used to determine atmospheric emissions from all of the process equipment simultaneously. The requirements of paragraph (g)(1) of this section are to be met. (ii) Method 107 is to be used to determine the concentration of vinyl chloride in each inprocess wastewater stream subject to the emission limit prescribed in §61.64(e). Vinyl chloride mass emissions are to be determined using the following equation: Crvc Qwater Dwater QK (10−6) Where: Ꮓ CBX Vinyl chloride emissions, g/kg (lb/lb) product in each inprocess wastewater stream. Crvc Concentration of vinyl chloride in wastewater, as measured by Method 107, ppmw. Dwater = Density of wastewater, 1.0 kg/m3 (0.0624 lb/ft3). Qwater Wastewater flow rate, determined in accordance with a method which has been submitted to and approved by the Administrator, m3/hr (ft3/hr). K = Unit conversion factor, 1,000 g/kg (1 lb/ lb). 10-6 Conversion factor for ppm. Z = Production rate, kg/hr (1b/hr), determined in accordance with a method which has been submitted to and approved by the Administrator. (5) The reactor opening loss for which an emission limit is prescribed in §61.64(a)(2) is to be determined. The number of reactors for which the determination is to be made is to be specified by the Administrator for each indi Ꮓ = Production rate, kg/hr (lb/hr). (A) If Method 106 is used to determine the concentration of vinyl chloride (C), the sample is to be withdrawn at a constant rate with a probe of sufficient length to reach the vessel bottom from the manhole. Samples are to be taken for 5 minutes within 6 inches of the vessel bottom, 5 minutes near the vessel center, and 5 minutes near the vessel top. (B) If a portable hydrocarbon detector is used to determine the concentration of vinyl chloride (Cы), a probe of sufficient length to reach the vessel bottom from the manhole is to be used to make the measurements. One measurement will be made within 6 inches of the vessel bottom, one near the vessel center and one near the vessel top. Measurements are to be made at each location until the reading is stabilized. All hydrocarbons measured are to be assumed to be vinyl chloride. (C) The production rate of polyvinyl chloride (Z), which is the product of the average batch weight and the number of batches produced since the reactor was last opened to the atmosphere, is to be determined by a method submitted to and approved by the Administrator. (ii) A calculation based on the number of evacuations, the vacuum involved, and the volume of gas in the reactor is hereby approved by the Administrator as an alternative method for determining reactor opening loss for postpolymerization reactors in the manufacture of bulk resins. Calculation methods based on techniques other than repeated evacuation of the reactor may be approved by the Administrator for determining reactor opening loss for postpolymerization reactors in the manufacture of bulk resins. (6) For a reactor that is used as a stripper, the emissions of vinyl chloride from reactor opening loss and all sources following the reactor used as a stripper for which an emission limit is prescribed in § 61.64(f) are to be determined. The number of reactors for which the determination is to be made is to be specified by the Administrator for each individual plant at the time of the determination based on the plant's operation. (i) For each batch stripped in the reactor, the following measurements are to be made: (A) The concentration of vinyl chloride in resin after stripping, measured according to paragraph (g)(3) of this section; (B) The reactor vacuum at end of strip from plant instrument; and (C) The reactor temperature at the end of strip from plant instrument. (ii) For each batch stripped in the reactor, the following information is to be determined: (A) The vapor pressure of water in the reactor at the end of strip from the following table: Where: VRVS = = VRVS = VR - VW WPVC DPVC Reactor vapor space volume, m3 (ft3) VR Reactor capacity, m3 (ft3) Vw = Volume of water in reactor from recipe, m3 (ft3) WPVC Dry weight of polyvinyl chloride in reactor from recipe, kg (lb) DPVC Typical density of polyvinyl chloride, 1,400 kg/m3 (87.4 lb/ft3) (iii) For each batch stripped in the reactor, the combined reactor opening loss and emissions from all sources following the reactor used as a stripper is to be determined using the following equation: CBX = K1 (PPMVC) + (PPVC)(VRVS) (Rvc) (Mvc) (TR+ KT) Where: Mpvc Dry weight of polyvinyl chloride in reactor from recipe, kg (lb) TR = KT = Reactor temperature, °C (°F) Temperature conversion factor for °C to °K, 273 (°F to °R, 460) (h)(1) Each piece of equipment within a process unit that can reasonably contain equipment in vinyl chloride service is presumed to be in vinyl chloride service unless an owner or operator demonstrates that the piece of equipment is not in vinyl chloride service. For a piece of equipment to be considered not in vinyl chloride service, it must be determined that the percent vinyl chloride content can be reasonably expected not to exceed 10 percent by weight for liquid streams or contained liquid volumes and 10 percent by volume for gas streams or contained gas volumes, which also includes gas volumes above liquid streams or contained liquid volumes. For purposes of determining the percent vinyl chloride content of the process fluid that is contained in or contacts equipment, procedures that conform to the methods described in ASTM D2267-68, 78, or 88 or D4420-94 (incorporated by reference as specified in § 61.18) shall be used. (2)(i) An owner or operator may use engineering judgment rather than the procedures in paragraph (h)(1) of this section to demonstrate that the percent vinyl chloride content does not exceed 10 percent by weight for liquid streams and 10 percent by volume for gas streams, provided that the engineering judgment demonstrates that the vinyl chloride content clearly does not exceed 10 percent. When an owner or operator and the Administrator do not agree on whether a piece of equipment is not in vinyl chloride service, however, the procedures in paragraph (h)(1) of this section shall be used to resolve the disagreement. (ii) If an owner or operator determines that a piece of equipment is in vinyl chloride service, the determination can be revised only after following the procedures in paragraph (h)(1) of this section. (3) Samples used in determining the percent vinyl chloride content shall be representative of the process fluid that is contained in or contacts the equipment. [41 FR 46564, Oct. 21, 1976, as amended at 42 FR 29007, June 7, 1977; 47 FR 39486, Sept. 8, 1982; 50 FR 46295, Nov. 7, 1985; 51 FR 34912, Sept. 30, 1986; 65 FR 62152, Oct. 17, 2000] § 61.68 Emission monitoring. (a) A vinyl chloride monitoring system is to be used to monitor on a continuous basis the emissions from the sources for which emission limits are prescribed in §§ 61.62 (a) and (b), 61.63(a), and 61.64 (a)(1), (b), (c), and (d), and for any control system to which reactor emissions are required to be ducted in § 61.64(a)(2) or to which fugitive emissions are required to be ducted in § 61.65 (b)(1)(ii), and (b)(2), (b)(5), (b)(6) (ii), and (b)(9)(ii). (b) The vinyl chloride monitoring system(s) used to meet the requirement in paragraph (a) of this section is to be a device which obtains representative samples from one or more applicable emission points on a continuous sequential basis and analyzes the samples with gas chromatography or, if the owner or operator assumes that all hydrocarbons measured are vinyl chloride, with infrared spectrophotometry, flame ion detection, or an alternative method. The vinyl chloride monitoring system used to meet the requirements in §61.65(b)(8)(i) may be used to meet the requirements of this section. (c) A daily span check is to be conducted for each vinyl chloride monitoring system used. For all of the emission sources listed in paragraph (a) of this section, except the one for which an emission limit is prescribed in § 61.62(b), the daily span check is to be conducted with a concentration of vinyl chloride equal to 10 ppm. For the emission source for which an emission limit is prescribed in §61.62(b), the daily span check is to be conducted with a concentration of vinyl chloride which is determined to be equivalent to the emission limit for that source based on the emission test required by § 61.67. The calibration is to be done with either: (1) A calibration gas mixture prepared from the gases specified in Sections 7.2.1 and 7.2.2 of Method 106 and in accordance with Section 10.1 of Method 106, or (2) A calibration gas cylinder standard containing the appropriate concentration of vinyl chloride. The gas composition of the calibration gas cylinder standard is to have been certified by the manufacturer. The manufacturer must have recommended a maximum shelf life for each cylinder so that the concentration does not change greater than ±5 percent from the certified value. The date of gas cylinder preparation, certified vinyl chloride concentration and recommended maximum shelf life must have been affixed to the cylinder before shipment from the manufacturer to the buyer. If a gas chromatograph is used as the vinyl chloride monitoring system, these gas |