Yes, hazardous chemicals present at rail yards are subject to EPCRA Sections 311 and 312, if they are NOT stored incident to transportation and they are present at the rail yard in amounts equal to or in excess of the minimum thresholds in 40 CFR 370.10(a).
As explained in the answer to the question “are hazardous chemicals in transportation subject to EPCRA 311/312,” the Section 327 exemption for substances stored “incidental to transportation” does not apply when substances are not under active shipping papers. The legislative history of EPCRA makes clear that the exemption for storage under Section 327 “is limited to the storage of materials which are still moving under active shipping papers and which have not reached the ultimate consignee.” House Report No. 99-962 (Committee of Conference), October 3, 1986, 99 Cong. Conf. H. Report 962, at 311. Thus, if a rail yard is identified as the ultimate consignee on the shipping papers, or the chemicals are not under active shipping papers, the hazardous chemicals present at the rail yard are no longer in transportation or stored incident to transportation.