Colorado air pollution regulators are advancing what’s been called one of the most stringent landfill methane rules in the country.

Dubbed Regulation 31, the proposed new regulation would establish earlier and lower triggers for mandatory methane gas collection systems at smaller landfills than are currently required by federal regulations.

Critics are concerned that rural landfills in smaller counties will be forced to close due to the high costs of installing such systems and that it’s a one-size-fits-all regulation that needs more flexibility.

The Air Quality Control Commission is expected to approve Regulation 31 later this month.

Written public comments on it must be submitted by 5 p.m. mountain time on Tuesday, August 5, at cdphe.aqcc@state.co.us. Registration for the Zoom meeting on August 20-22 to make public comment can be found at cdphe.colorado.gov/aqcc.

Under the proposed rule, landfills containing more than about 408,000 metric tons must report their waste-in-place volume by March 31, 2026, and sites generating more than 664 metric tons of methane per year must install gas collection and control systems.

Federal law requires methane gas control and collection systems for large landfills that contain more than 2.5 metric tons of waste or exceed 500 parts per million of methane in the air at the surface.

In advance of the AQCC meeting, methane detection and measurement technologies developed in Colorado for use at municipal solid waste landfills were showcased at an online webinar on Thursday, hosted by the Rocky Mountain Institute and the Colorado School of Mines Payne Institute for Public Policy.

Grand Valley Instrumentation, TrelliSense, LongPath Technologies, Project Canary, and ChampionX Aviation, as well as experts from the Colorado School of Mines and RMI discussed the need for measurement and quantification of landfill methane and presented descriptions of their products and how they can be used effectively to monitor and measure landfill emissions.

ChampionX

Mackensie Smith, director of airborne operations at Boulder-based ChampionX Aviation highlighted the company’s specially modified fixed-wing aircraft that can fly over landfills or other potential methane emission sources to quantify leakage. Smith also presented information on the company’s use of drone-based monitoring, which saves time and expense for operators who ordinarily have to do walking measurements on a regular basis.

LongPath Technologies

Greg Reiker, co-founder and chief technology officer of LongPath Technologies of Boulder, explained the frequency comb laser system LongPath is installing over 24,000 square miles in the nation’s most active oil and gas fields in Texas, Oklahoma, Kansas, Colorado, North Dakota, and New Mexico. The company is installing 1,000 systems as part of a $163.3 million loan from the U.S. Department of Energy.

The LongPath technology uses precisely-tuned laser frequencies that are only absorbed by methane molecules to both detect leaks and quantify them by measuring how much infrared light is sent out and how much returns from a reflector. The quantum laser technology was developed at the University of Colorado’s Department of Mechanical Engineering.

Grand Valley Instrumentation

Rikky Cook, co-founder of Grand Valley Instrumentation in Grand Junction, highlighted the company’s Meerkat Monitoring System that autonomously samples and adjusts landfill wellhead systems to keep complex methane gathering systems operating optimally under varying atmospheric and underground conditions.

The Meerkat continuous monitoring and adjustment system replaces time-consuming and hazardous manual monitoring, Cook said, providing reliable data for automated compliance reporting.

TrelliSense

Boulder-based TrelliSense provides ground-based systems for wide-area methane leak monitoring and quantification. CEO Ben Silton presented the company’s two-part, ground-mounted system that uses proprietary quantum spectroscopy technology and solar power to provide portable monitoring for landfills.

The TrelliBeam system bounces an invisible laser off a retroreflector to detect point-source methane leaks up to 300 meters away and an accuracy of about 30 meters.

The TreliiSun system uses the sun as a light source to measure methane using an auto-tracking solar sensor that follows the sun’s path and known position to localize methane plumes using a mesh array of sensors to quantify methane over large areas.

Project Canary

Denver’s Project Canary Senior Scientist Ali Lashgari presented the company’s data quantification platform that can accept and analyze data from almost any detection and measuring system and output information to help operators better understand landfill emissions through continuous monitoring and analysis.

The system is intended to provide operators with “defensible data to come up with a data-driven mitigation action.”

The webinar is available for viewing online.