Iowa Department of Transportation
INDEX  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Access Management

Utility Policy

Utility Policy
back

Pipeline Crossings


Overview
The following standard specifications are considered to be minimum design standards for pipeline facilities that cross the Iowa Department of Transportation right-of-way.  In general, a pipeline crossing should maintain the minimal standards of the latest version as published by the American National Standards Institute (ANSI) and the latest version of the utility policy (Iowa Administrative Code 761, Chapter 115 (306A)).  The department shall deny the issuance of a permit if it determines there is insufficient room for additional utility facilities with the right-of-way.

Accordingly, the applicant should consider the following during the design process and prior to the submission of an application. In general, there are two types of pipeline crossings – Flammable/Volatile or Non-Flammable.

Flammable/Volatile Pipeline Crossings
  • All pipelines shall be cased from right-of-way to right-of-way on existing highways.
  • Casing shall be at least 10% larger that the outside diameter of the carrier pipe but no less than 2 inches greater than the largest outside diameter of the carrier pipe.
  • Maintain a minimum depth of pipeline crossing is 48”as measured from the top of pavement at the edge of the roadway.
  • All underground crossings shall cross as near perpendicular to the roadway as possible.  In any event, the crossing should be no less than a 60 degree angle relative to the roadway.
  •  
  • The casing shall be cathodically protected.
  • The casing shall be coated in accordance to ANSI and other generally accepted industry standards.
  • The pipeline crossing shall be vented and marked at the outer limits of the right-of-way.
Non-Flammable Pipeline Crossings
  • All pipelines shall be cased from right-of-way to right-of-way on existing highways.
  • Casing shall be at least 10% larger that the outside diameter of the carrier pipe but no less than 2 inches greater than the largest outside diameter of the carrier pipe.
  • Maintain a minimum depth of pipeline crossing is 48”as measured from the top of pavement at the edge of the roadway.
  • All underground crossings shall cross as near perpendicular to the roadway as possible.  In any event, the crossing should be no less than a 60 degree angle relative to the roadway.