Insituform Technologies, Inc. Files Lawsuit Against Former Executives.

CHESTERFIELD, Mo. -- Insituform Technologies, Inc. (Nasdaq/National Market: INSU) announced today that it filed a lawsuit against three former executives (primarily from its Affholder tunneling subsidiary), Jerome Shaw, Robert Affholder and Thomas Kalishman, as well as the recently formed Missouri companies SAK Construction, LLC, SAK Construction of CA, LP and SAK Construction of California, Inc.

The lawsuit, filed in St. Louis County Circuit Court, alleges violation of employment, non-compete and independent contractor agreements. The suit also alleges that the three former executives misappropriated Insituform's confidential information in order to compete unfairly with the Company. In addition, the lawsuit charges that the defendants wrongfully interfered with the Company's contracts with at least two current employees of the Company.

In its suit, Insituform seeks preliminary and permanent injunctive relief against the defendants; damages in excess of $25,000, including punitive damages; an award for damages against Mr. Shaw for profits he realized through the exercise of stock options over the last three years; and the assessment of costs and attorney's fees.

Separately, Insituform announced that recently it had sent a cease-and-desist letter to William Elmore, who had sold Elmore Pipe Jacking to the Company in 2002, advising him he had breached his non-compete agreement. Mr. Elmore's attorney acknowledged the breach and has advised Insituform that Mr. Elmore will comply fully with the non-compete agreement, which expires in May 2007.

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 Insituform can be found on its Internet site at www.insituform.com.