Exhibit 99.1 FIRST AMENDMENT TO SEVENTH AMENDED AND RESTATED CREDIT AGREEMENT FIRST AMENDMENT TO SEVENTH AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”), dated as of May 27, 2022 by and among GFL ENVIRONMENTAL INC., a corporation existing under the laws of Ontario, Canada (the “Canadian Borrower”), GFL ENVIRONMENTAL USA INC., a corporation existing under the laws of Delaware (the “US Borrower”), the Guarantors party hereto, BANK OF MONTREAL, as administrative agent (in such capacity, the “Administr ...