X0306 4 2019-04-24 0000353020 Aegion Corp AEGN 0001216708 WRIGHT PHILLIP D 17988 EDISON AVE. CHESTERFIELD MO 63005 1 Common Stock 2019-04-24 4 A 0 5100 0 A 54094 D Common Stock 2019-04-24 4 A 0 63 0 A 54157 D Common Stock 10000 I Individual Retirement Account Historically, the reporting person has reported deferred stock unit ("DSU") grants as a separate line item. Going forward, the reporting person will combine both DSUs and Class A common stock, $0.01 par value per share ("Common Stock"), on one line, as has been done on this Form 4. Annual award of DSUs. Each DSU represents the issuer's obligation to transfer one share of Common Stock in accordance with the terms of the deferred stock unit agreement pursuant to which the DSUs were granted. The DSUs were granted under the issuer's Non-Employee Director Equity Plan, and are subject to a one-year vesting period from the date of grant. Once the DSUs vest, shares of Common Stock equal to the number of DSUs reflected in the reporting person's account will be distributed to the reporting person either promptly following termination of the reporting person's service on the issuer's Board of Directors or, at the reporting person's election of a specified distribution date. Grant of DSUs in lieu of increase in cash retainer for board service during the second quarter 2019 as a result of becoming chair of the Compensation Committee. Each DSU represents the issuer's obligation to transfer one share of Common Stock in accordance with the terms of the deferred stock unit agreement pursuant to which the DSUs were granted. The DSUs were granted under the issuer's Non-Employee Director Equity Plan, and are immediately vested upon grant. Promptly following termination of the undersigned's service on the issuer's Board of Directors or, at the undersigned's election, a specified distribution date, the issuer will distribute to the undersigned shares of Common Stock equal to the number of DSUs reflected in the undersigned's account at such time. /s/ Mark A. Menghini, as Attorney-in-Fact for Phillip D. Wright 2019-04-26