Procedures
(i) Procedures. The procedures specified in paragraphs (c)(2)(i)(A) through (C) of this section are considered acceptable procedures for determining the mass flow rate. They may be used in combination, and no one procedure shall take precedence over another. (A) Knowledge of the wastewater. You may use knowledge of the wastewater stream and/or the process to determine the annual average mass flow rate. You shall use the maximum expected annual average production capacity of the dyeing/finishing operation(s), knowledge of the process, and/or mass balance information to either estimate directly the average wastewater mass flow rate for the compliance period or estimate the total wastewater mass flow for the compliance period and then factor the total mass by the percentage of time in the compliance period the operating scenario is expected to represent. Where you use knowledge to determine the annual average mass flow rate, you shall provide sufficient information to document the mass flow rate. (B) Historical records. You may use historical records to determine the average annual mass flow rate. Derive the highest annual average mass flow rate of wastewater from historical records representing the most recent 5 years of operation, or if the dyeing/finishing operation(s) has(have) been in service for less than 5 years but at least 1 year, from historical records representing the total operating life of the process unit. Where historical records are used to determine the annual average mass flow rate, you shall provide sufficient information to document the mass flow rate. (C) Measurement of mass flow rate. If you elect to measure mass flow rate, you shall comply with the requirements of this paragraph. Measurements shall be made at the point of determination, or at a location downstream of the point of determination with adjustments for mass flow rate changes made according to paragraph (c)(2)(ii) of this section. Where measurement data are used to determine the annual average mass flow rate, you shall provide sufficient information to document the mass flow rate. (ii) Adjustment for flow rates determined downstream of the point of determination. You shall make corrections to the average annual mass flow rate of a wastewater stream when it is determined downstream of the point of determination at a location where either wastewater streams from outside of the affected dyeing/finishing operation or group of dyeing/finishing operations have been mixed with the affected wastewater stream or one or more wastewater streams have been treated. You shall make corrections for such changes in the annual average mass flow rate. (3) Wastewater treatment. You shall document that the wastewater is either discharged to a POTW or onsite secondary wastewater treatment. (4) Determine the mass of organic HAP in the affected wastewater. Determine the total mass of organic HAP, WW, contained in the wastewater streams characterized by the procedures in paragraphs (c)(1) and (2) of this section, using Equation 7 of this section: