THE CORPORATE LIBRARY

Related Party Transactions and Outside Related Director Information

Insituform Technologies, Inc. (INSU)

3/10/2006 Proxy Information

Affholder, Inc., our wholly-owned subsidiary that comprises the tunneling segment, owns, or leases under long term operating leases with third-party leasing companies, several pieces of tunneling equipment, including cranes and tunnel boring machines. From time to time for specific projects, Affholder, Inc. will lease additional equipment from a variety of sources. During 2005, Affholder, Inc. leased four cranes and two tunnel boring machines from A-Y-K-E Partnership. A-Y-K-E is a partnership that is controlled by Robert W. Affholder, a former member of our board of directors who retired effective with our 2005 annual meeting of stockholders. During 2005, Affholder, Inc. paid A-Y-K-E approximately $0.7 million pursuant to equipment leases. This amount represents approximately 14.8% of all lease payments made by Affholder, Inc. during 2005 and 3.5% of all lease payments made by us in 2005. The cranes and tunnel boring machines that were leased to Affholder, Inc. during 2005 were leased under separate lease agreements on terms that were substantially similar to, or better than, those otherwise available to Affholder, Inc. in the market. The leases were terminable upon 30 daysŐ prior notice by either party. Affholder, Inc. also was entitled under the leases to sublease the equipment to third parties and retain any profit generated from the sublease.

Brett Affholder, the son of Robert W. Affholder, is employed by Affholder, Inc. as Regional Equipment Manager. For fiscal year 2005, Brett Affholder received total compensation of $104,221 from Affholder, Inc.

3/24/2005 Proxy Information

Affholder, Inc., our wholly-owned subsidiary that comprises the tunneling segment, owns, or leases under long term operating leases with third-party leasing companies, several pieces of tunneling equipment, including cranes and tunnel boring machines. From time to time for specific projects, Affholder, Inc. will lease additional equipment from a variety of sources. During 2004, Affholder, Inc. leased four cranes and two tunnel boring machines from A-Y-K-E Partnership. A-Y-K-E is a partnership that is controlled by Robert W. Affholder, our former Senior Executive Vice President and a member of our board of directors. During 2004, Affholder, Inc. paid A-Y-K-E approximately $460,000 pursuant to equipment leases. This amount represents 8.6% of all lease payments made by Affholder during 2004 and 2.1% of all lease payments made by us in 2004. The cranes and tunnel boring machine that are currently under lease are leased under separate lease agreements on terms that are substantially similar to, or better than, those otherwise available to Affholder, Inc. in the market. The leases are terminable upon 30 days' prior notice by either party. During 2004, A-Y-K-E leased equipment only to Affholder, Inc. Affholder, Inc. may sublease the equipment to third parties and retain any profit generated from the sublease.

Brett Affholder, the son of Robert W. Affholder, is employed by Affholder, Inc. as Position Project Manager. For fiscal year 2004, Brett Affholder received total salary and incentives of $76,256 from Affholder, Inc.

3/31/2004 Proxy Information

Affholder, Inc., our wholly-owned subsidiary that comprises the tunneling segment, owns, or leases under long term operating leases with third-party leasing companies, several pieces of tunneling equipment, including cranes and tunnel boring machines. From time to time for specific projects, Affholder, Inc. will lease additional equipment from a variety of sources. During 2003, Affholder, Inc. leased four cranes and one tunnel boring machine from A-Y-K-E Partnership. A-Y-K-E is a partnership that is controlled by Robert W. Affholder, our Senior Executive Vice President and a member of the board of directors. During 2003, Affholder, Inc. paid A-Y-K-E approximately $510,000 pursuant to equipment leases. This amount represents 7.5% of all lease payments made by Affholder during 2003 and 2.9% of all lease payments made by us in 2003. The cranes and tunnel boring machine that are currently under lease are leased under separate lease agreements on terms that are substantially similar to, or better than, those otherwise available to Affholder, Inc. in the market. The leases are terminable upon 30 days' prior notice by either party. During 2003, A-Y-K-E leased equipment only to Affholder, Inc. Affholder, Inc. may sublease the equipment to third parties and retain any profit generated from the sublease.

4/16/2003 Proxy Information

Affholder, Inc., our wholly-owned subsidiary that comprises the tunneling segment, owns, or leases under long term operating leases with third-party leasing companies, several pieces of tunneling equipment, including cranes and tunnel boring machines. From time to time for specific projects, Affholder, Inc. will lease additional equipment from a variety of sources. During 2002, Affholder, Inc. leased five cranes from A-Y-K-E Partnership. A-Y-K-E is a partnership that is controlled by Robert W. Affholder, our Executive Vice President and a member of the board of directors. During 2002, Affholder, Inc. paid A-Y-K-E approximately $600,000 pursuant to crane equipment leases. This amount represents 10.4% of all lease payments made by Affholder during 2002 and 4.4% of all lease payments made by us in 2002. The cranes that are currently under lease are leased under separate lease agreements on terms that are substantially similar to, or better than, those otherwise available to Affholder, Inc. in the market. The leases are terminable upon 30 days' prior notice by either party. During 2002, A-Y-K-E leased equipment only to Affholder, Inc. Affholder, Inc. may sublease the cranes to third parties and retain any profit generated from the sublease.