Distribution Integrity Management Program (DIMP)


Distribution Integrity Management Program (DIMP)


The Pipeline Inspection, Protection, Enforcement and Safety Act of 2006 required the U.S. Department of Transportation (DOT) to establish a regulation prescribing standards for integrity management programs for distribution pipeline operators. DOT formally proposed the Distribution Integrity Management Program (DIMP) rule in June 2008.

Much of the proposed rule is consistent with the themes and conclusions drawn by the DIMP Phase 1 Report, Integrity Management for Gas Distribution Pipelines, issued by DOT in December 2005. The level of documentation required in the proposed rule placed an undue burden on industry, as the documentation required did not account for the diverse nature of distribution systems. AGA proposed that operators be required to document significant changes made to their DIMP programs, not all changes. The proposed rule stipulated that operators submit plastic pipe data to a mandatory PHMSA database. AGA stated that the existing Plastic Pipe Database Committee (PPDC), which consists of members from industry and the regulatory community, adequately addresses DOT s concerns. In addition, the proposed rule included prescriptive language to address human factors and risk mitigation. Congress only mandated DOT to address human factors as it applies to control room management. AGA stated that programs and regulations are already in place to address human factors on distribution system operations and there is no basis for fatigue management under DIMP. The proposed rule included language for operators to use technology and data analysis to support alternate inspection intervals. AGA is supportive of the alternate inspection intervals concept proposed by the DOT.

A task group of the Gas Piping Technology Committee (GPTC), with participation by many AGA member companies, developed a guidance document that will help clarify the requirements of the DIMP rule. The GPTC guidance document has been drafted and will be revised, as necessary, to conform to the final rule.

AGA held a workshop in August 2008 for industry to voice concerns regarding the DIMP proposed rule. DOT and the National Association of Pipeline Safety Representatives participated in the workshop. AGA submitted its comments on the proposed rule in October 2008. DOT's Technical Pipeline Safety Standards Committee (TPSSC) met in December 2008 to discuss the proposed rule. During the December meeting, the TPSSC voted to support a DIMP final rule that addresses the concerns raised by AGA. The final rule is expected to be promulgated in late 2009.

AGA Contacts: Christina Sames, 202-824-7214, csames@aga.org; Kyle Rogers, (202) 824-7218, krogers@aga.org


Assessing the Fitness for Service of Distribution Pipelines

Natural gas is a clean burning and abundant energy source that cleanly fuels the life of 177 million Americans nationwide. Natural gas is delivered through pipeline systems of varying size and material type to customers for residential, commercial and industrial use. Natural gas pipelines, which transport approximately one-fourth of the energy consumed in the United States, are an essential part of the nation s infrastructure.
Managing the Nation's Cast Iron Inventory

The AGA Board of Directors has designated Pipeline Safety as the number one priority of its member companies. It encompasses the repair, replacement and reconditioning of pipelines and related facilities and is a primary focus of natural gas utilities as they maintain safe and reliable operations.
Gas Distribution Annual Report Form & Mechanical Fitting Failure Report Form

DOT has issued its new distribution annual reporting form, mechanical fitting failure reporting form and instructions.  The Gas Distribution System Annual Report form was revised in 2010 to incorporate new data elements related to DIMP.  Operators are expected to report 2010 data using the revised Gas Distribution Annual Report form included below.  Operators should also note that the new Mechanical Fitting Failure Report form is now a separate form from the distribution annual form and is also included below.  Operators are not required to report mechanical fitting fail
Management of Vintage Distribution Pipelines Workshop (Sept 2011)

The "Management of Vintage Pipelines Under DIMP" workshop focused on strategies taken by gas distribution operators under DIMP in management of vintage pipelines such as cast iron, bare steel, copper, and plastic pipe subject to brittle-like cracking. Strategies addressed included identification & prioritization, monitoring practices, and implementation of replacement plans.There were also discussions and presentations on:
PHMSA Guidance for Pipeline Safety Evaluation & Metrics (Oct 15, 2014)

On October 15, PHMSA published in the Federal Register an Advisory Bulletin informing operators of “elements and characteristics of a mature Integrity Management program evaluation process using meaningful metrics” through a document titled “Guidance for Strengthening Pipeline Safety Through Rigorous Program Evaluation and Meaningful Metrics.” (also attached).PHMSA states that the guidance document:… should be used when operators develop and perform IM program evaluations.