Insituform Technologies Awarded Contract Extension Valued at $6.0 Million from Scottsdale, Arizona

Insituform Technologies, Inc. (Nasdaq Global Select Market: INSU) announced today that it has received a contract extension from the City of Scottsdale, Arizona valued at approximately $6.0 million for the cured-in-place pipe rehabilitation of 75,000 feet of small- and medium-diameter wastewater pipelines. This negotiated contract is the first one-year extension of the initial three-year term contract and provides the City of Scottsdale the option to extend for a fifth year.

Ken Foster, Vice President and General Manager of Insituform Technologies, said, “Our work in Scottsdale allows us to rehabilitate valuable underground pipelines with minimal disruption to residents. Once rehabilitated, we expect this network of pipelines to last for several decades. As always, we remain focused on providing experienced project management as we partner with the City of Scottsdale.”

Insituform expects to conduct this work from September 2011 through mid-year 2012.

Earlier this year, Insituform was awarded the Project of the Year by the Arizona American Public Works Association (APWA) Chapter in the Environment Category for projects under $5 million for another project in nearby Phoenix, Arizona. The project, which utilized the InsituMain® System, a glass-reinforced cured-in-place pipe solution for pressurized pipelines, has been nominated for national recognition by the APWA in the same category.

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.

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 any 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®, InsituMain® and the Insituform® logo are the registered trademarks of Insituform Technologies, Inc. and its affiliates.