Document O3kKQXm8jQQyd9oOQNO9ky4mL

a. Method 17, which is central to the test methods specified, cannot practicably or safely be employed at the smelter roofline vents, in conjunction with the other test methods that are specified, to determine roofline PM emissions rates in pounds per hour. b. Satisfying the requirement, at 63.1450(e)(v), to "waive" isokinetic calculations will inevitably cause the roofline PM emissions rates that are calculated using the methods specified to be unrepresentative of actual PM emissions rates at the roofline. 2. The PM emissions-rate limit in 40 C.F.R. 63.1444(h), on the grounds that, absent a test method that can practicably and safely be implemented or result in calculated PM emissions rates that are representative of actual PM emissions rate at the roofline, a roofline PM emissions-rate limit, such as that specified in 63.1444(h), should not be imposed. Rather, the comprehensive design and work practice standards that are separately imposed in the Copper Rules specifically to control process-fugitive PM emissions should constitute the extent of the Copper Rules' provisions that are geared to limit PM emissions at the roofline. 3. The test methods specified at 40 C.F.R. 63.1450(g) for determining compliance with the smelter roofline Pb emissions-rate limit in 40 C.F.R. 63.1444(p)(1), on the grounds that: a. Method 17, which is central to the test methods specified, cannot practicably or safely be employed at the smelter roofline vents, in conjunction with the other test methods that are specified, to determine roofline Pb emissions rates in pounds per hour; and, b. Satisfying the requirement, at 63.1450(e)(v), to 'waive" isokinetic calculations will inevitably cause the roofline Pb emissions rates that are calculated using the methods specified to be unrepresentative of actual Pb emissions rates at the roofline. 4. The Pb emissions-rate limit in 40 C.F.R. 63.1444(p)(1), on the grounds that, absent a test method that can practicably and safely be implemented or result in calculated Pb emissions rates that are representative of actual Pb emissions rate at the roofline, a roofline Pb emissions-rate limit, such as that specified in 63.1444(p)(1), should not be imposed. Rather, the comprehensive design and work practice standards that are separately imposed in the Copper Rules specifically to control process-fugitive Pb emissions should constitute the extent of the Copper Rules' provisions that are geared to limit Pb emissions at the roofline. Asarco's concerns regarding the Copper Rules' imposition of Method 17 and "waiver" of isokinetic calculations, in 40 C.F.R. 63.1450(e) and 63.1450(g), are amplified as follows: A. It is basically impossible to accomplish Method 17 sampling across and within the large ventopenings of the smelter building. Those vent-openings are situated along the roofline of the smelter building in conditions of extreme heat that arise from the smelting, converting and anode-refining operations below--which are further exacerbated during the hot Arizona summers. The temperatures at the roofline often exceed 150 degrees Fahrenheit. We are justifiably reluctant to require an Asarco employee or contractor to stand at the vent-openings and maneuver the sampling probe, across and within the vent-openings, in that environment, to the degree and for the duration needed to collect a robust set of samples according to the procedures specified in 40 C.F.R. 63.1450(e) and 63.1450(g). B. The purpose of isokinetic sampling, which is a standard feature of Method 17, is amply stated in the administrative record, as to in-stack sampling to determine compliance with process stack emissions. That purpose is to ensure a representative collection by drawing the sample from the stack at the same velocity as the gas stream, which is crucial for accurate emissions measurements Sierra Club FOIA 2025-EPA-04883 ED_018388_00000318-00002 SC_EVERSPLIT0006295