Natural Gas Leaks in the District of Columbia

Overview

Natural gas leaks by occurrence and type

Natural Gas Quality of Service Standards (NGQSS)

In addition to monitoring WGL gas leak data reported to PHMSA, the DCPSC adopted Natural Gas Quality of Service Standards that requires WGL to provide, among other things, quarterly detailed leak reports, known as the Leak Identification, Detection, and Repair, and Odor Complaints report (LIDAROC). This report contains, among other things, a numeric grade for each leak, the type of leak, a location of leak (including the ward), the gas pressure involved, the number of customers affected, the cause of the leak, an estimated and actual time to repair the leak, and other actions taken. Leak reporting requirements to the DCPSC are more stringent and detailed than the summarized annual gas leak reporting provided by WGL to PHMSA. The DCPSC monitors WGL’s performance quarterly and annually.
 
All leaks reported to the DCPSC in the LIDAROC process are graded 1 through 3. A Grade 1 leak refers to a hazardous leak that presents an immediate or probable hazard to persons or property and requires immediate repair or continuous action until the conditions are no longer hazardous. A Grade 2 leak refers to a leak that is recognized as being non-hazardous at the time of detection, but requires scheduled repair based on probable future hazard. Grade 2 leaks are monitored and scheduled for repair, but do not require immediate action. A Grade 3 leak refers to a leak that is non-hazardous at the time of detection and can be reasonably expected to remain non-hazardous. Grade 3 leaks are monitored to ensure they do not worsen. Grade 1 and Grade 2 leaks reported to the Commission are generally included in the leaks reported to PHMSA.

The DCPSC oversees WGL compliance with NGQSS and monitors the utility’s performance both quarterly and annually.

WGL activities

Repairs
WGL undertakes extensive gas leak repair efforts every year, including emergency repairs. WGL’s total leak repair costs in 2019 totaled $22.2 million. Annual leak repair expenses fluctuate based on the number and nature of the leaks as well as the magnitude of repairs needed.
 
WGL also has an ongoing level of normal replacement work. The company invested $88 million over a 7-year period, to include retiring about 12 miles of main and nearly 5,800 gas service lines in the District. WGL previously worked to fix vintage mechanical couplings, an approximately $75 million investment that covered 27 miles of gas main pipe, nearly 3,700 service lines, and 20,000 couplings.  
 
WGL also executes many accelerated pipe replacement programs (see below).
 
Leak survey and detection
In addition to responding to leak calls reported by the public, WGL conducts periodic leak survey activities throughout the District through six survey cycles according to the characteristics of the area and the piping systems present. Leakage surveys are systematic inspections used to locate any leaks in a gas piping system. A survey consists of testing and inspection of the area around the pipelines with gas detection equipment by a qualified technician. The entire distribution system is surveyed on a three-year cycle, exceeding the five-year minimum requirement outlined in federal regulations.

Piping description	Leak survey cycle
Business districts	Annual
Places of public assembly	Annual
High-pressure transmission systems	Six months or twice per year
Cast iron systems (above 1psig)	Annual
Gas mains on structures in commercial districts	Three months or four times per year
Gas mains on structures in non-commercial areas	Six months or twice per year

WGL has also embarked on a new $1.4 million pilot program to review, test, and deploy advanced leak detection technology equipment and practices. These include satellite-based technology and advanced vehicle-mounted sensing equipment. The DCPSC continues to monitor the evolution of this pilot program.
 

DCPSC pipeline safety, damage prevention, and service quality activity

The DCPSC Office of Compliance and Enforcement (OCE) coordinates pipeline safety and damage prevention efforts for the Commission which complement federal laws and regulations governing gas pipeline safety, damage prevention, and pipeline operations, maintenance, and construction. OCE staff include PHMSA-trained and certified inspectors whose certifications are continually updated through on-going pipeline safety courses. OCE continuously conducts pipeline safety inspections, averaging about 315 inspections per year since 2017, as well as damage prevention inspections, averaging about 750 inspections per year since 2017.

OCE also monitors gas pipeline damage incidents caused by excavation activity in the District. WGL experienced 136 gas pipeline damage incidents in 2021 in DC, representing about a 5% reduction from 2017 incidents, despite higher levels of excavation.
 
OCE may propose monetary and non-monetary compliance and enforcement actions if necessary for WGL to comply with federal and District laws and regulations. Monetary penalties serve as a deterrent to future violations and unsafe practices and are not recovered in utility rates. The DCPSC pipeline safety and damage prevention efforts are audited annually by PHMSA and the U.S. Department of Transportation. The Commission received consecutive 100% scores on PHMSA annual audits from 2014-2020.

PROJECTpipes
PROJECTpipes is WGL’s accelerated pipeline replacement program to modernize the natural gas distribution system in the District and enhance overall system safety, reliability, and resiliency for gas customers. This program helps the District meet its climate goals by reducing potential leaks and methane gas emissions on the distribution system. WGL estimates that the total reduction in greenhouse gas (GHG) emissions from 2021-2023 will be approximately 6,000 metric tons of CO2e. The DCPSC estimates that this project will help avoid more than 100 leaks in that timeframe.
 
WGL has replaced or remediated 28.6 miles of high-risk gas main and 5,188 service lines through the PROJECTpipes program as of Dec. 31, 2021.
 

Updates

Commission staff will periodically update this gas leak data and other relevant information with the latest annual information reported by WGL.