1-D ID 21-312 Approve the Sixth Amendment to the Consultant Services Agreement with Provost and Pritchard Consulting Group, Inc., to extend the Agreement term from March 31, 2021 to January 15, 2022 (no additional funds), for Engineering Design and Feasibility Analysis for Removal of 1,2,3-Trichloropropane from Groundwater Extraction Wells, for a previously approved contract amount of $1,020,000 (Citywide)