State OKs PGW gas-main replacement plan, including nearly 1,000 miles of pipes installed before WWII

You may have noticed quite a few street closures in Philadelphia in recent years to dig up and replace aging gas mains. The work is not going to let up.

State regulators on Thursday approved a plan for city-owned Philadelphia Gas Works to continue an accelerated pace of refurbishing its aging and leaky natural gas distribution system, including more than 950 miles of gas mains that were installed before World War II.

The Pennsylvania Public Utility Commission voted 3-0 to approve the municipal utility’s five-year infrastructure improvement plan, which includes a surcharge of up to 7.5% on customer bills to pay for the additional gas-main replacement.

In its filing with the state, PGW said the accelerated gas main replacement plan will make its system safer, reduce leaks of methane that contribute to greenhouse gas emissions, and reduce the frequency and need to repair leaky gas mains. The utility last year reported about 1,798 “hazardous” leaks of gas mains and service lines connected to customers, or about five hazardous leaks a day.

» READ MORE: What to know about Philly’s old, brittle gas mains

“PGW’s Long-Term Infrastructure Improvement Plan continues the acceleration of PGW’s efforts to respond to climate change by significantly eliminating methane emissions, modernize Philadelphia’s energy infrastructure, and maintain the safety and reliability of its system at a minimal cost to ratepayers,” the company said in a statement on Thursday.

In the last 17 years, the company said its improvements had reduced over 78,000 metric tons of “carbon dioxide equivalent,” or about 3,100 metric tons of natural gas or methane, which is a far more potent greenhouse gas than carbon dioxide.

Even at an accelerated pace, the PGW gas-main replacement program may be moving too slowly to satisfy climate advocates such as the Clean Air Council, which says that 1-2% of natural gas leaks directly into the atmosphere from older urban gas utilities like PGW. The Clean Air Council has argued that the city should transition PGW away from gas distribution.

PGW plans to replace about 31 miles a year of its 3,046-mile gas distribution system, or 155 miles over the five years covered by the plan. That’s about 2% per year of the 1,715 miles of the system’s “at risk” gas mains made from cast iron or “unprotected coated steel.”

The plan also includes the replacement of 4,271 bare-steel gas service lines, connecting customers to the new gas mains. PGW replaces its gas mains and service lines with plastic PVC pipes.

PGW had been replacing about 18 miles of gas main a year before the state in 2013 first gave the company the authority to use the infrastructure surcharge, called a distribution system improvement charge. That fee generates about $38.6 million a year from customers to pay for the additional 16 miles of gas main replacement.

Even under the accelerated program, PGW estimates it will take 40 years to replace 1,246 miles of cast iron mains, which are the oldest pipes on its system. Nearly 1,000 miles of gas mains were installed before 1940. Cast iron becomes embrittled with age and is at greater risk of breakage from underground earth subsidence.

The PUC pressed PGW to accelerate its gas-main replacement plan after a Tacony gas leak in 2011 killed a utility worker and injured five others. The state complained that the city, trying to keep its gas rates in check, had not maintained an adequate pace of gas-main replacement.

After City Council in 2014 declined a $1.9 billion offer to sell PGW to a private utility that promised to ramp up infrastructure spending, the PUC put even more pressure on PGW to speed up the gas-main replacement program, increasing the infrastructure surcharge from 5% to 7.5%.

You can find PGW’s current pipe replacement projects here.