Insituform Technologies Awarded Coating Contracts Valued at $5.0 Million

Insituform Technologies, Inc. (Nasdaq Global Select Market: INSU) announced today that its subsidiary, The Bayou Companies, LLC (“Bayou”), has been awarded contracts totaling approximately $5.0 million to provide the corrosion coating for the export lines delivering natural gas from the Walker Ridge Gathering System, an ultra-deepwater project located in the Gulf of Mexico, and the Big Foot pipeline that connects production facilities to existing subsea pipeline infrastructure.

Bayou will provide fusion bonded epoxy coating for the Walker Ridge Gathering System and Big Foot Development projects. Upon completion, the Walker Ridge Gathering System will include approximately 190 miles of 8-inch and 10-inch diameter pipelines. The pipelines will be located at depths of 5,900 to 7,000 feet in the Gulf of Mexico.

Bayou will also provide the corrosion coating for the Big Foot Pipeline, a 40-mile, 20-inch diameter pipeline that connects 100,000 b/d of production to existing subsea pipeline infrastructure.

Dorwin Hawn, Senior Vice President of Insituform’s Energy & Mining Group, said, “Bayou is very excited to be part of the Walker Ridge and Big Foot Development projects. We believe these project awards demonstrate our customer’s confidence in Bayou’s ability to execute at a highly technical and demanding level.”

Bayou expects to begin these projects in the fourth quarter 2011.

About Insituform Technologies, Inc.

Insituform Technologies, Inc. is a global leader in pipeline protection. Insituform provides proprietary technologies and services for rehabilitating sewer, water, energy and mining piping systems and the corrosion protection of industrial pipelines. More information about the Company can be found on its internet site at www.insituform.com.

About The Bayou Companies, LLC

The Bayou Companies, LLC, a subsidiary of Insituform Technologies, Inc., is a leading provider of cost-effective solutions to onshore and offshore energy and infrastructure companies primarily in North America and the Gulf of Mexico. Bayou’s products and services include internal and external pipeline coating, lining, weighting and insulation. Bayou also provides specialty fabrication and services for offshore deepwater installations, including project management and logistics. More information about Bayou can be found on its internet site at www.bayoucompanies.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, 2010, as filed with the Securities and Exchange Commission on February 28, 2011 and in our subsequent quarterly reports on Form 10-Q. In light of these risks, uncertainties and assumptions, the forward-looking events may not occur. In addition, our actual results may vary materially from those anticipated, estimated, suggested or projected. Except as required by law, we do not assume a duty to update forward-looking statement, 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.

Insituform®, Bayou™, Global Pipeline Protection®, the Insituform® logo and the Bayou® logo are the registered and unregistered trademarks of Insituform Technologies, Inc. and its affiliates.