Corrugated polyethylene (PE) tubing, couplings, and fittings for subsurface drainage shall meet the requirements of Section 4143.01B of the Standard Specifications of the Iowa Department of Transportation.


Acceptance of these materials will be based on approved brand name and manufacturing plant.




Application for plant approval shall be made, in writing, to the Office of Materials in Ames and shall include product technical information and a description of product quality control procedures.


Initial approval will be based on the review of the information in the application. A current report of successful NTPEP Plant Audit will be used for Plant Approval.


At the end of every calendar year, each approved manufacturer shall give a statement summarizing the quantities of their product usage by Iowa DOT to the Manufactured Materials Engineer in the Office of Materials. The statement shall contain the description, length and diameter of the tubing supplied to various Iowa DOT projects during the year.


Approved manufacturing plants for corrugated PE tubing and fittings used for subsurface drainage which have supplied more than 3 projects for Iowa DOT are listed in Appendix A.




Acceptance shall be on the basis of approved manufacturers as listed in Appendix A.



Sampling and testing at the project site will be based on requests from the Central Materials Office. Samples shall contain the date and plant code.


Monitor test sample shall consist of the same number and lengths as described in AASHTO M 254 Specification. Deficient test results or poor workmanship on any monitor sample may be considered sufficient cause for removing a plant from the list of approved suppliers.