This action involves a continued approval of an alternative monitoring method to the Portland cement industry direct final rule which was originally intended as a short term solution to a timing issue relative to compliance demonstrations. In July 2016, when this alternative monitoring method was first published (via a direct final rulemaking), it was believed that hydrogen chloride (HCl) calibration gases would become available within a period of 1 year (i.e., the rule provides for the use of this alternative monitoring method until July 25, 2017). The calibration gases are needed for compliance demonstrations relative to the HCl continuous monitoring requirements of the portland cement industry final rule. However, as the 1-year deadline approached, it became apparent that the calibration gases would not be widely available for operators, and the date when the calibration gases would become readily available was uncertain. For this reason, we developed a direct final rule/parallel proposal to extend the alternative monitoring method until such time when the calibration gases became available. (Note that this change will affect only kilns that do not have HCl controls, which are required to continuously monitor for HCl.) The direct final rule/parallel proposal included an alternative method for HCl compliance that requires a yearly stack test along with the HCl monitors performing as parametric monitors instead of direct continuous monitoring. The direct final rule/parallel proposal was published on June 23, 2017, and the EPA received adverse comment on June 29, 2017, from EarthJustice. The Agency withdrew the direct final rulemaking, and re-proposed the alternative to allow time for the public to submit comments. We are currently reviewing the comments submitted on the proposed rule, and intend to finalize this alternative monitoring method as proposed, allowing sufficient time for the Portland cement manufacturing industry to acquire the necessary HCl calibration gases as required by the Portland Cement Manufacturing NESHAP. This action is being subsumed into the Portland Cement Risk and Technology Review, RIN: 2060-AS92.