Response Protocol for Large Underground Methane Emissions



Colorado State University and the University of Texas at Arlington were recently awarded a major project to better understand gas migration from moderate-to-large underground leaks, validating models to understand those leaks, and developing methods to assess and respond to these leaks.  Underground natural gas pipeline leakage, especially at moderate to high flow rates, can result in gas migration and buildup, producing explosive concentrations within nearby substructures. A critical knowledge gap is knowing how environmental conditions affect gas migration behavior in these scenarios, and how emergency first responders can factor them into decision making. As part of the project, we review historical incident reports from PHMSA and identify if conclusions drawn from our field measurements could have prevented the incident. This project addresses PHMSA’s request for high resolution field tests for model validation by using novel above/below ground sensors to characterize gas migration speed and distance at high leakage rates and concentrations above explosive limits. This work will:

  • Advance methods to characterize significant natural gas leaks from buried pipelines,
  • Advance leak detection and repair methods for pipeline leaks, especially large leak scenarios,
  • Deliver an empirical understanding of large leak behavior that can be incorporated into first responder and leak detection protocols.

Colorado State University and the University of Texas at Arlington will collaborate with industry and first responder partners, who will be members on a technical advisory panel, provide access to their response protocols, and, in some cases, participate in field testing. Controlled field testing will be performed at CSU’s Methane Emission Technology Evaluation Center and, potentially, at DOT’s Transportation Technology Center in Pueblo, Colorado. 


The project will focus on underground natural gas (NG) leaks with moderate to high flow rates (>100 scfh) that can produce explosive concentrations nearby.  Proposed work will advance the understanding of gas migration behavior and provide decision guidance for stakeholders by:

  1. Making direct measurements of gas migration speed and extent at the surface, and in the subsurface, in a range of environmental conditions.
  2. Pairing measurements with models to extend knowledge beyond measurable scenarios.
  3. Linking gas concentration measurements with observations of environmental conditions to estimate extent and speed of gas migration.

Opportunities to Participate:

Interested in participating?  There are several ways to get engaged in this project:

  • Industry advisory Board (IAB) – The IAB is an opportunity for stakeholders of all types to be included in planning and steering the focus of controlled experiments.
  • Controlled testing – Controlled testing at METEC will be performed following the protocol developed in this project. Contact us for information on how to participate.
  • Field test sites – Operators may partner with us to test flow rates in different soils during the field testing. Contact us for information on how to participate.

View the project award here. Contract ID: 693JK32010011POTA. Proposal title is: Validating Models for Predicting Gas Migration and Mitigating its Occurrence/Consequence


  • University of Texas – Arlington
  • Fort Lewis College
  • White Plains Fire Department
  • Poudre Fire Authority
  • Western Metro Fire Department
  • Western Midstream
  • Con Edison
  • Southern California Gas company
  • Pacific Gas and Electric Company
  • Pipeline and Hazardous Materials Safety Administration
  • Colorado Oil & Gas Conservation Commission