Nov 07, 2014 · b. Phosphoric Acid Manufacturing NSPS Emission Regulations. The EPA promulgated 40 CFR part 60, subpart T for WetProcess Phosphoric Acid Plants on August 6, 1975 (40 FR 33154). The NSPS established standards to control total F emissions from WPPA plants, including reactors, filters, evaporators and hot wells.