SERDP and ESTCP released supplemental solicitations requesting proposals for demonstration and validation of environmentally sustainable technologies or methodologies for cleaning firefighting delivery systems in aircraft hangars or on firefighting vehicles that have contained per- and polyfluoroalkyl substances (PFAS)-based fire-fighting foams beginning in FY 2020. The due date for all proposals is November 21, 2019 by 2 p.m. ET.