12 Dec A Decade into DIMP, Pipe Replacement Still Keeps Workforce Busy
Article by Michael Reed in Pipeline & Gas Journal
While systematic evaluation of natural gas pipelines has been going on for decades, the impetus for much of the work that is currently underway comes from the Distribution Integrity Management Program (DIMP), a federal regulation that went into effect in December 2009.
Under the Pipeline and Hazardous Materials Safety Administration (PHMSA) guideline, identification of threats, along with prioritization and mitigation of risks, must be reported by companies.
Chief among the concerns that ushered in the era of DIMP was that cast-iron and uncoated steel pipelines, and the early vintage polymer (Aldyl-A) pipes, which were widely used in the 1970s and early 1980s, were aging and prone to cracks.
As a result, operators were given 18 months from the date of the guideline’s issuance to develop and implement a written plan.
With so many companies involved in natural gas distribution (P&GJ reported on 200 of such companies, ranging in size from nearly 6 million to 6,400 customers in the Annual 500 Report in November), this summary of ongoing infrastructure replacement projects is intended as overview of current activity and is not an all-inclusive summary.
A decade after the advent of DIMP, much progress has been. Among the companies at the forefront of the effort is CenterPoint company Vectren, which has replaced more than 700 miles of pipe since its program began in 2008.
“To ensure the continued reliability of our natural gas pipeline systems and service, Vectren continues our program to replace essentially all of our bare steel and cast-iron pipeline infrastructure in Indiana and Ohio,” said Richard Leger, vice president of Natural Gas Distribution, Indiana and Ohio. “These infrastructure enhancements are vital to meeting federal requirements and ensuring safe delivery of natural gas service to our customers for decades to come.”
In addition, Vectren has replaced more than 430 miles of pipe in Ohio and has about 720 miles of bare steel and cast iron pipe left to address in its system. The company plans to be completed in 2024.
The company expects to replace 140 miles of pipe in 2019 at a total investment of $108 million in 47 cities, according to data from the Business Social Compliance Initiative (BSCI).
Washington Gas is another company that has made great strides in its replacement efforts. As of Dec. 31, 2018, the company had replaced 227 miles of mains and 56,000 services, of which 113 miles was mechanically coupled pipe, 63 miles was unprotected steel pipe, and 38 miles was cast iron pipe.
Washington Gas estimates there are 394 miles of unprotected steel, 681 miles of targeted mechanically coupled, and 478 miles of cast iron pipe remaining in its system.