Serco Inc., Herndon, Virginia, has been awarded a maximum $19,783,501 modification (P00030) exercising the fourth one-year option period of a one-year base contract (SP3300-17-C-5003) with four one-year option periods for chemical management services. This is a firm-fixed-price with cost-reimbursement and cost-plus-fixed-fee contract. Locations of performance are Virginia, North Carolina, Florida and California, with a May 15, 2022, performance completion date. Using customer is Defense Logistics Agency Aviation. Type of appropriation is fiscal 2021 through 2022 defense working capital funds. The contracting activity is the Defense Logistics Agency Distribution, New Cumberland, Pennsylvania.