Aegion Corporation Awarded Contract from City of Montreal Valued at $13.4 Million (USD)

Aegion Corporation (“Aegion” or the “Company”) (Nasdaq Global Select Market: AEGN) today announced its subsidiary, Insituform Technologies Limited (“Insituform Canada”), was awarded a $13.4 million (USD) contract from the City of Montreal, Quebec, Canada to rehabilitate pipelines up to 130 years old, located mostly in residential areas in boroughs throughout the city.

Insituform Canada will rehabilitate approximately 11 miles of egg-shaped brick pipelines and 10-inch to 42-inch diameter combined sewer system pipelines using its air inversion steam cure installation method, which reduces energy usage during installation by approximately 95 percent. In addition, Insituform Canada will internally reinstate approximately 3,400 service laterals using robotic cutters. In order to meet the demands of this project, Insituform expects to add up to three new positions at its Montreal wet out plant.

Ken Foster, President of Insituform Canada, said, “Since opening our office here in 2010, we have been awarded nine contracts from the City of Montreal with a combined value of over $33 million and have rehabilitated over 16 miles of pipelines throughout the city and its boroughs. Insituform Canada is proud to continue its partnership with the City of Montreal and remains committed to providing a superior installation with minimal disruption to this community.”

Work on the project is expected to begin immediately and be completed by May 2015.

About Aegion Corporation

Aegion Corporation is a global leader in infrastructure protection and maintenance, providing proprietary technologies and services: (i) to protect against the corrosion of industrial pipelines; (ii) to rehabilitate and strengthen water, wastewater, energy and mining piping systems and buildings, bridges, tunnels and waterfront structures; and (iii) to utilize integrated professional services in engineering, procurement, construction, maintenance and turnaround services for a broad range of energy related industries. Aegion’s business activities include manufacturing, distribution, maintenance, construction, installation, coating and insulation, cathodic protection, research and development and licensing. More information about Aegion can be found on our internet site at www.aegion.com.

About Insituform Technologies Limited

For over thirty years, Insituform Technologies Limited, a Canadian subsidiary of Aegion Corporation, has been a leader in the development and installation of proprietary technologies and services for rehabilitating sewer, water and other underground piping systems without digging or disruption. More information about Insituform Technologies can be found on its Internet site at www.insituform.com.

Forward-Looking Statements

The Private Securities Litigation Reform Act of 1995 provides a “safe harbor” for forward-looking statements. The Company makes forward-looking statements in this news release that represent the Company’s beliefs or expectations about future events or financial performance. These forward-looking statements are based on information currently available to the Company and on management’s beliefs, assumptions, estimates or projections and are not guarantees of future events or results. When used in this document, the words “anticipate,” “estimate,” “believe,” “plan,” “intend,” “may,” “will” and similar expressions are intended to identify forward-looking statements, but are not the exclusive means of identifying such statements. Such statements are subject to known and unknown risks, uncertainties and assumptions, including those referred to in the “Risk Factors” section of the Company’s Annual Report on Form 10-K for the year ended December 31, 2013, as filed with the Securities and Exchange Commission on February 28, 2014, and in the Company’s subsequent quarterly reports on Form 10-Q. In light of these risks, uncertainties and assumptions, the forward-looking events may not occur. In addition, the Company’s actual results may vary materially from those anticipated, estimated, suggested or projected. Except as required by law, the Company does not assume a duty to update forward-looking statements, whether as a result of new information, future events or otherwise. Investors should, however, review additional disclosures made by the Company from time to time in its periodic filings with the Securities and Exchange Commission. Please use caution and do not place reliance on forward-looking statements. All forward looking-statements made by the Company in this news release are qualified by these cautionary statements.

Aegion®, Insituform®and the Aegion® logo are the registered trademarks of Aegion Corporation and its affiliates.