CLOSE Act Mandates EPA to List Hydrogen Sulfide as Hazardous Pollutant, Ends Oil and Gas Emissions Loophole

The newly proposed Closing Loopholes for Oil and other Sources of Emissions Act, or the CLOSE Act, is straightforward: it tightens up how the oil and gas industry is regulated under the Clean Air Act. This legislation targets two specific areas: an existing exemption that allowed emissions to be grouped together and the classification of a highly toxic gas called hydrogen sulfide.

Closing the Emissions Aggregation Loophole

First, the bill repeals a specific exemption within the Clean Air Act (Section 112(n)). This exemption previously allowed emissions from multiple oil and gas sources—like various wells or processing facilities—to be aggregated, or counted together, for regulatory purposes. By removing this aggregation allowance, the bill essentially requires facilities to be considered individually for certain air quality rules. For the industry, this means that individual sites that previously flew under the regulatory radar because their emissions were counted as part of a larger, aggregated group might now face stricter requirements if their standalone emissions exceed federal thresholds. For communities near these operations, this change means potentially better air quality monitoring and regulation at a site-by-site level.

Hitting the Hazard List: Hydrogen Sulfide

The second, and arguably more significant, part of the CLOSE Act deals with hydrogen sulfide (H2S). If you’ve ever smelled rotten eggs near an oil or gas site, you’ve likely encountered this gas. It’s highly toxic, even deadly at high concentrations, and is often a byproduct of drilling and extraction. The bill mandates the Environmental Protection Agency (EPA) to officially list H2S as a hazardous air pollutant (HAP) within 180 days of the bill becoming law. This is a big deal because once a substance is listed as a HAP, the EPA is required to set national emission standards for it.

After listing H2S as a HAP, the EPA must then spend the next year (365 days) revising its source lists to specifically include oil and gas wells as major sources of this pollutant. This means that after these deadlines pass, oil and gas companies will have to comply with new, stricter emission controls specifically designed to reduce H2S releases. For people living and working near drilling sites, this mandatory regulation could lead to a tangible improvement in air quality and reduced health risks associated with H2S exposure.

The Real-World Impact on Your Community

If the CLOSE Act passes, the biggest change won't be immediate, but it will be mandatory and time-bound. The industry will face increased compliance costs as they invest in new technology to capture or control H2S emissions and meet stricter site-specific regulations. For example, a small production facility that previously didn't have to report or control its H2S emissions might now need to install specialized equipment to meet the new federal standards. While this means higher operating costs for the companies, it translates directly into better public health protection for nearby residents. It’s a classic trade-off: increased regulatory scrutiny and cost for the industry in exchange for cleaner air and fewer associated health risks for the public.