Leading Proxy Advisory Firms Agree That Wam Control Of Insituform Is Counter To Best Interests Of Stockholders

Chesterfield, MO - May 9, 2008 - Insituform Technologies, Inc. (Nasdaq Global Select Market: INSU) today issued the following statement in response to dissident stockholder Water Asset Management's  ("WAM") misrepresentation of the conclusion of proxy advisory firm Glass Lewis & Co.:
        
This is an another example of the ever-changing strategy of misstatements, distortions and misrepresentations that Water Asset Management has employed in its effort to take control of Insituform by electing its slate of five under-qualified, hand-picked nominees. Contrary to the misleading impression that WAM seeks to foster, Glass Lewis did not endorse its bid for control of the company. In fact, Glass Lewis said in its May 2 report that it was "not swayed by the Dissident's argument that it should control a majority of the seats on the board of directors."

Insituform urged its stockholders to follow the recommendation of  leading proxy advisory firm RiskMetrics Group (formerly ISS), to vote FOR all of Insituform's directors on the Company's WHITE proxy card today and prevent Water Asset Management from taking control of Insituform at the Company's Annual Meeting of Stockholders on May 19, 2008. Both RiskMetrics and Glass Lewis agree that WAM's agenda - replacing a majority of your Board with its slate of five hand-picked nominees - is NOT in the best interests of ALL Insituform stockholders.

Stockholders with questions or who need assistance voting their shares may call the Company's proxy solicitor, Innisfree M&A Incorporated, at (888) 750-5834.

About Insituform
Insituform Technologies, Inc. is a leading worldwide provider of proprietary technologies and services for rehabilitating sewer, water and other underground piping systems without digging and disruption. More information about the Company can be found on its Internet site at www.insituform.com.       

Additional Information
Insituform has filed a definitive proxy statement with the Securities and Exchange Commission ("SEC") in connection with its 2008 Annual Meeting. Insituform's stockholders are strongly advised to read the definitive proxy statement carefully, as it contains important information.  Free copies of the definitive proxy statement, and any amendments or supplements thereto, and other materials filed by Insituform with the SEC will be available free of charge on the SEC's website at www.sec.gov, on Insituform's website at www.insituform.com under Investors/SEC or by directing requests to Insituform's proxy solicitor, Innisfree M&A Incorporated, toll free at (888) 750-5834.     

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 document 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 and 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, 2007, as filed with the Securities and Exchange Commission on March 10, 2008.  In light of these risks, uncertainties and assumptions, the forward-looking events discussed 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 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 document are qualified by these cautionary statements.

Insituform®, the Insituform® logo, Insituform Blue®, United Pipeline Systems® and Clean Water for the World® are the registered trademarks of Insituform Technologies, Inc. and its affiliates.

CONTACT:

David A. Martin
Vice President and Chief Financial Officer
Insituform Technologies, Inc.
636-530-8000

Matthew Sherman / Dan Katcher
Joele Frank, Wilkinson Brimmer Katcher
212-355-4449