UPDATED: EPA proposes MACT revisions

By Anna Austin | December 02, 2011

Following a reconsideration period, the U.S. EPA has proposed revisions to its Maximum Achievable Control Technology standards for certain boilers and incinerators.

Since the release of the proposed rule in April 2010 and the final rule in February 2011, the standards have seen significant push-back from multiple industries, including the biomass industry, because of significant compliance costs. The final rules were published in the Federal Register on March 21, although the standards for major source boilers and commercial and industrial solid waste incinerators are currently suspended.

The proposed changes are based on extensive analysis, review and consideration of data and input from states, environmental groups, industry, lawmakers and the public. While they cut the cost of implementation by nearly 50 percent from the original 2010 proposed rule, they still meet important requirements laid out in the 1990 Clean Air Act Amendments, according to the EPA.

The MACT rules encompass standards for four source categories—major source industrial, commercial and institutional boilers and process heaters; area source industrial, commercial and institutional boilers; commercial and industrial solid waste incinerators; and sewage sludge incinerators—as well as an updated definition of solid waste, crucial in determining which rules a technology will fall under.

The major source proposal covers approximately 14,000 boilers, which is less than 1 percent of all boilers in the U.S., located at large sources of air pollutants, including refineries, chemical plants and other industrial facilities. The new changes propose to create additional subcategories and revise emissions limits, as well as provide more flexible compliance options for meeting the particle pollution and carbon monoxide limits.

“Because of the diverse and complex nature of these sources, EPA has worked extensively with industries, states, environmental groups and other key stakeholders to develop the standards we’re outlining today,” said Gina McCarthy, assistant administrator for the EPA’s Office of Solid Waste & Emergency Response, during a press conference to outline and explain the proposed changes. “This input has helped EPA better understand the sources so we apply the right standards to the right boilers.”

For boilers located at major sources of air toxic emissions, McCarthy said the EPA set a bit more flexible standards while maintaining health benefits. “EPA is proposing to make adjustments, one of which is replacing dioxin emission limits with work practice standards, a reflection of our new, more robust analysis that shows that dioxin emissions are below those we can accurately detect.”

The EPA will continue to monitor solid waste incinerator emissions limits, according to McCarthy, but based on input and more data, they have been slightly adjusted. “We’ve revised some dioxin and mercury limits and some monitoring requirements,” she said.

Mathy Stanislaus, assistant administrator for EPA’s Office of Solid Waste and Emergency Response, discussed the changes to the Non-Hazardous Secondary Materials (NHSM) rule. One proposed change clarifies that certain biomass materials are already included within the scope of clean biomass as a traditional fuel under current regulation. “This includes ag-derived biomass, crop residue including vines, orchard trees, hulls, and other biomass crops used for the production of cellulosic biofuels, including hogged fuel, untreated wood pallets, wood pellets, and wood debris from urban areas,” he said.

Stanislaus said EPA is proposing to categorically list several NHSMs as not being solid waste when burned as a fuel in a combustion unit where EPA has sufficient information to determine that discard is not occurring when these materials are being used as fuels. “The agency recognizes that certain NHSMs may not meet the legitimacy criteria in all instances, but after balancing the legitimacy criteria with other relevant factors, the material would still generally be considered a nonwaste fuel,” he said. “In addition, EPA is seeking comment on whether pulp and paper wastewater treatment sludges and coal refuse from legacy piles should also be categorically identified as nonwastes.”

McCarthy noted that these are not official but proposed changes, and the public will have 60 days to comment on them.

As the rules were released Dec. 2, the biomass industry is still learning what the potential impacts may be. American Forest & Paper Association President and CEO Donna Harman said the MACT boiler rules are among the most complex MACT standards developed. “We are committed to thoroughly reviewing the changes put forth by EPA today to assess the affordability and achievability of the proposal,” she said.

Harman said the reconsideration is an important step toward writing a more reasonable set of regulations after being forced by the courts to finalize rules in March, which the agency itself recognized as flawed. “Our nation’s economy needs regulations that protect the environment while sustaining American manufacturing jobs,” she added. “Unfortunately, these rules remain open to challenge in the courts, which has prolonged the process by years already; this creates an atmosphere of uncertainty that prevents investment and thwarts American manufacturing competitiveness.”

"We are pleased that the EPA's revised standards look to achieve major public health benefits while further adjusting the rules to meet real world boiler operating conditions," said Joseph Seymour, executive director of the Biomass Thermal Energy Council. "Striking a balance to meet clean air standards without placing high compliance costs on the renewable energy industry can be a difficult task, and BTEC welcomes EPA's ongoing process."

Bob Cleaves, president of the Biomass Power Association, said that while the new boiler MACT rules are complicated and still under thorough review by the BPA, it’s important to note that the biomass industry appreciates the EPA having taken a step back to make what the association believes are important changes in the rules that govern its industry. "For example, emission levels that the best technology in the industry can’t even measure have now been replaced with work practice standards,” Cleaves said. “Those include emission levels that regulate dioxin, as well as mercury.”

Of equal importance, EPA listed biomass materials considered fuel and not solid waste. “The important point there is that biomass consumed in boilers is regulated very differently than material consumed in incinerators,” Cleaves said. “The biomass industry doesn’t utilize incinerators. This is an important step, and certainly recognition by the EPA of the kind of fuels that we use.”

He added that the rules are complicated and very lengthy and still being digested by the BPA, but the association’s initial take on what the EPA has done is generally positive.

To view all of the proposed changes, visit www.epa.gov/airquality/combustion.