Business groups have asked Colorado regulators to postpone an April hearing regarding new toxic-air-contaminant rules, arguing that adopting reporting rules before knowing how the information will be used could create a risk of setting unrealistic standards.
Legislators in 2022 mandated the state to identify at least five air toxic contaminants that posed elevated risks to state residents’ health and adopt regulations that go beyond federal rules to limit emissions of them. In February, the Colorado Air Quality Control Commission selected the first five contaminants — picking toxics emitted by sources ranging from combustion engines to manufacturing facilities to wastewater-treatment plants — and in April is scheduled to approve reporting standards for them.
After that, the Air Pollution Control Division is scheduled to take the crucial step of proposing health-based standards for the contaminants by May and getting them approved by the AQCC in September. Business leaders and several members of a working group that advised the APCD have cautioned that adopting such standards without knowing how they will be used — such as whether chosen standards will be the cap under which emitters must lower their output of the toxic — is problematic at best and dangerous at worst.
Chamber files delay request
To try to slow that process, the Colorado Chamber of Commerce submitted a request that the AQCC postpone establishing rules for reporting of toxic air contaminants, or TACs, until it can address uncertainties on how the health-based standards will be used. The reason: the Chamber and other business groups fear the de minimis reporting thresholds that will be proposed — thresholds “based on overly conservative modeling,” it argues — will become the health-based standards, an option that the APCD has discussed.
That in turn could make it near impossible to operate everything from oil and gas wells to glass-making factories to sewage-treatment plants by establishing standards that are technically or economically infeasible, the groups argue. Thus, the motion for dismissal of a portion of the April hearing reads, officials shouldn’t create reporting standards until it’s developed other key rules for TACs and can explain how each standard will be used, enforced and reported.
“A TAC reporting rule should not be adopted until there is a better understanding of how the reporting component will relate to the other components of the air toxics program,” wrote Christy Woodward, regulatory affairs advisor for the Chamber. “There is potential to misinform the public as well as risk that de minimis thresholds will ultimately be adopted as health-based standards or considered a metric for when risks are likely to occur.”
Joining with the Chamber in its request for a delay are Metro Water Recovery, the Joint Industry Working Group of the oil-and-gas sector, the Western & Rural Local Government Coalition, the Colorado Petroleum Association, Suncor and GCC Pueblo. Only the APCD and Local Government Coalition, made up largely of Front Range cities and counties, opposed the motion.
Why three hearings on toxic air contaminants are linked
AQCC members also are scheduled to approve new fees on emissions and emissions reporting at the April meeting, but the business groups have not opposed that effort. Instead, leaders in impacted industries have asked that the money being raised by fee increases that reach as 67% be put toward resources aimed at making the permitting system quicker and more efficient.
The rulemakings around TACs are trickier, however, because of the uncertainty surrounding how some of the toxics can be limited or controlled. And, as such, the creation of both health-based standards and emission control regulations must be done carefully — and should be done together rather than separately, as is now proposed with the standards hearing set for September and the regulations due for approval by April 2026.
Metro Water Recovery’s request to postpone the hearing to establish TAC-reporting rules may best illustrate the conundrums that business leaders say they face. AQCC members chose hydrogen sulfide, a toxic gas emitted in sewage treatment, as one of the five priority TACs, leaving the largest wastewater treatment facility between Chicago and Los Angeles unsure of what to do. Adding covers to extensive wastewater flow areas will at best require enormous infrastructure costs that will be reflect in hikes on customers’ bills and at worst is impossible, officials said.
Working group members split on how to proceed
The de minimis levels above which all emissions of the TACs must be reported include the value of a risk of one in 1 million cases for cancer risk and low hazard quotients for TACs that present non-cancer risks. Those non-cancer risks are any effects from the toxics that can touch on vital organs, ranging from cardiovascular to reproductive issues and more, and are meant to be low so that their impacts can be added to risks from other toxics to assess cumulative impacts, said Michelle Mason, a senior staff scientist at Earthjustice and member of the working group.
The U.S. Environmental Protection Agency and other states set these health quotients well below the point at which health effects are observed so that they can account for unknown factors, said Tami McMullen, a senior toxicologist for environment-consulting firm CTEH who also served on the working group. Because of that, these numbers are intended as guideline values for the state to watch, not hard standards that are meant to go into law as caps on how much businesses can emit, McMullen said.
“That’s why many of us on the committee felt it was a challenging thing to say what numbers would be used (for health-based standards and reporting) until you understand how it would be used,” McMullen said at a Feb. 21 presentation to the AQCC.
Commissioners, who don’t meet as a body in March, must decide soon whether to postpone the hearing to set reporting standards or to continue with it in April. The decision is likely to set the tone for how the even more rancorous debates about health-based standards and emission-control regulations will proceed.