Exhibit 21

SUBSIDIARY LIST

(as of February 21, 2011)

Company Name Place of Incorporation

Bayou Coating, L.L.C.1 Bayou Perma-Pipe Canada, Ltd.2 Bayou Welding Works, L.L.C. Commercial Coating Services International, LLC Corrpro Canada Holdings, Inc. Corrpro Canada, Inc. Corrpro Companies Europe Ltd. Corrpro Companies, Inc. Corrpro Companies International, Inc. Corrpro Holdings LLC Delta Double Jointing, LLC 3 INA Acquisition Corp. Insitu Envirotech (S.E. Asia) Pte. Ltd. Insituform Asia Limited Insituform Belgium N.V. Insituform CV Insituform Cyprus Limited Insituform Environmental Techniques Ltd. 4 Insituform Europe SAS Insituform Holdings BV Insituform Holdings (UK) Limited Insituform Hong Kong Limited Insituform-Hulin Rohrsanierungstechniken S.R.O. 5 Insituform Hulin Kft.  6 Insituform Limited Partnership Insituform Linings Asia Sdn Bhd Insituform Linings Limited Insituform Pacific Pty Limited Insituform Pipeline Rehabilitation Private Limited 7 Insituform Rioolrenovatietechnieken B.V. Insituform Rohrsanierungstechniken GmbH 8 Insituform Singapore Pte. Ltd. Insituform sp. z o.o. Insituform SPML JV 9 Insituform s.r.o. 10 Insituform Technologies CV Insituform Technologies Ibérica S.A. Insituform Technologies Limited Insituform Technologies Limited Insituform Technologies Netherlands BV Insituform Technologies USA, Inc. ITI International Services, Inc. KA-TE Insituform AG Mississippi Textiles Corporation Ocean City Research Corporation The Bayou Companies, LLC United Pipeline de Mexico S.A. de C.V. 11 United Pipeline Middle East, Inc. United Pipeline Systems International, Inc. United Pipelines Inversiones Limitada United Pipelines SRL United Sistemas de Revestimento em Tubulações Ltda. United Sistema de Tuberias Limitada Video Injection – Insituform SAS Wilson Walton Anti Corrosivos Ltd. Wilson Walton Group Ltd. Louisiana Alberta, Canada Louisiana Texas Delaware Alberta, Canada United Kingdom Ohio Nevada Delaware Delaware Delaware Singapore Hong Kong Belgium The Netherlands Cyprus Northern Ireland France The Netherlands United Kingdom Hong Kong Slovakia Hungary New Brunswick, Canada Malaysia United Kingdom Australia India The Netherlands Germany Singapore Poland India Czech Republic The Netherlands Spain Alberta, Canada United Kingdom The Netherlands Delaware Delaware Switzerland Mississippi New Jersey Delaware Mexico Delaware Delaware Chile Argentina Brazil Chile France Portugal United Kingdom

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1 The Bayou Companies, LLC holds a 49% interest in Bayou Coating L.L.C.  The Bayou Companies, LLC holds a 59% interest in Delta Double Jointing, LLC and Bayou Coating L.L.C. holds the other 41% interest.

2 Insituform Technologies Limited (Alberta, Canada) holds a 51% interest.

3 See Note 1.

4 Insituform Technologies Limited (UK) holds a 50% interest.

5 Insituform Technologies Limited (UK) holds a 50% interest in Insituform Rohrsanierungstechniken GmbH.    Insituform Rohrsanierungstechniken GmbH holds a 51% interest in Instuform-Hulin Rohrsanierungstechniken S.R.O. (Slovakia).  Insituform-Hulin Rohrsanierungstechniken S.R.O. holds a 100% interest in Insituform Hulin Kft. (Hungary) and Insituform s.r.o. (Czech Republic).

6 See Note 5.

7 Insituform Technologies Netherlands BV holds a 50.5% interest.

8 See Note 5.

9 Insituform Technologies, Inc. holds a 50% interest.

10 See Note 5.

11 INA Acquisition Corp. Holds a 55% interest.