Oregon Air Toxics Rules: Final Proposal Adopted
By J. Mark Morford, Thomas R. Wood
11/1/2003

On October 9th, 2003, the Oregon Environmental Quality Commission (EQC) adopted the air toxics rules the Oregon Department of Environmental Quality (DEQ) has been developing over the past five years. The final rules maintain the fundamental structure and concepts that have appeared in prior drafts of the rules. However, DEQ has incorporated important changes in response to public comment. The most important of these changes are: clarification of the risk assessment criteria; an assurance that any new requirements will be proportionate to a source's contribution to ambient levels; and clearer prioritization of geographic areas that will require local planning efforts.

As discussed in previous Insider Articles (Wood, Insiders #302, #311, & #320; and Morford/Wood, Insider #316), the rules create three new subprograms. The primary subprogram is called the geographic subprogram because it is intended to focus on discrete geographic areas (e.g., Portland metropolitan area) and resolve specific air toxics concerns within those areas. If a source located outside one of the designated areas is clearly the sole cause of an air toxics concern, DEQ also has the "safety net" portion of the air toxics rules. The safety net subprogram authorizes DEQ to establish source specific controls where specific criteria are met. The third subprogram, referred to as the "source category" subprogram, authorizes DEQ to promulgate statewide categorical rules based upon standards it develops as part of the geographic subprogram and/or the safety net subprogram. Each of the three subprograms will involve additional public processes before new requirements can be imposed on sources.

The starting point for all three subprograms is the ambient benchmark. For any of the three subprograms to be triggered, DEQ must have documented ambient levels of air toxics that are unsafe. A prerequisite to implementing the program, therefore, will be determining what ambient concentration levels will be considered safe. The term used in the air toxics rules to define what level is safe is "ambient benchmark."

Determining what is a safe ambient concentration will not be a straightforward task. The US Environmental Protection Agency (EPA) has not set safe ambient levels except for a few hazardous air pollutants. In order to fill this gap, the new rules provide that DEQ will appoint a volunteer scientific advisory committee to help develop the ambient benchmarks-the Air Toxics Scientific Advisory Committee (ATSAC). DEQ is tasked by rule with developing proposed ambient benchmarks. To spearhead the development of the proposed benchmarks, DEQ has transferred toxicologist Bruce Hope from its Land Quality Division to the Air Quality Division. Once DEQ has developed the proposed benchmarks, it will present them to the ATSAC for a maximum of 12 months review. After the ATSAC finishes its review, DEQ must go through the rulemaking process, complete with public comment, in order to finalize the benchmarks.

The new rules provide that the benchmarks are to be set at ambient air concentrations that would equate to an excess cancer risk of one-in-one million (for carcinogens) or a hazard quotient of one (for non-carcinogens). The final rules include new language taken from the Oregon Cleanup Law that provides guidance for the risk assessment process. In particular, the rules state that the benchmarks at to be set "based upon a protocol that uses reasonable estimates of plausible upper-bound exposures that neither grossly underestimate nor grossly overestimate risks."

Just which pollutants will be the first candidates for benchmark development is not yet determined. According to Greg Lande of DEQ, the agency is likely to focus first on the pollutants identified as potential problems in the1996 National Air Toxics Assessment, but DEQ is anticipating an updated assessment from EPA that could change the focus somewhat. Pollutants expected to be addressed initially include: formaldehyde; benzene; acrolein; polycyclic organic matter; chloroform; diesel particulate; 1-3 butadiene; perchloroethylene; acetaldehyde; nickel; chromium; lead; and arsenic. Many of these are produced by fossil fuel combustion, especially from mobile sources.

The cornerstone of the new air toxics program is the Geographic Program. The new rules require DEQ to identify one or more areas in the state that exceed the ambient benchmarks. The rules require DEQ to start with high priority areas with ambient pollutant levels significantly above the benchmarks (e.g., levels ten times a benchmark for a carcinogen or levels above a hazard quotient of one with the potential for serious adverse health effects).

Of significant importance, the revised final rule language clearly requires DEQ to base selection of geographic areas on "representative monitoring" in public areas. Prior versions of the rule had suggested that DEQ could rely on modeling or emission inventories to select geographic areas. The requirement for monitoring data assures that geographic areas will not be selected without clear evidence that an actual air toxics problem exists--as opposed to a more hypothetical risk suggested by modeling. The shortage of resources to conduct monitoring, however, will require that DEQ focus its monitoring efforts on a limited number of areas.

DEQ currently has monitoring data for several areas in Portland that identifies some pollutants at levels above what are likely to be the new ambient benchmarks, particularly pollutants associated with mobile source emissions. According to Mr. Lande, DEQ intends to identify the Portland area as its first geographic area. Because ambient benchmarks first must be set, the formal selection of Portland is not likely to occur for another two years.

Based on EPA's National Air Toxics Assessment, DEQ has identified the following cities as potentially having an air toxics problem: Portland; Medford; Salem; LaGrande; McMinnville; Baker City; Eugene/Springfield; Albany/Millersburg; and Klamath Falls. DEQ currently is seeking legislative approval to accept EPA funding for monitoring in La Grande as a representative rural community in the National Air Toxics Trends Network. DEQ also has recently collected limited air toxics data in the Albany area in the course of testing monitoring equipment for possible purchase. That data is not yet publicly available. Limited monitoring data also has been collected in the Eugene/Springfield area, where the Lane Regional Air Pollution Authority (LRAPA) will administer the new rules.

The final rules include new language to further clarify that any mandatory requirements of the local plan must be commensurate with source contributions. DEQ's Summary of Public Comment and Agency Response includes a clear statement of intent that the local plans will equitably allocate any new requirements. This change is particularly important to the industrial stationary sources that are typically small contributors of air toxics but potentially the easiest regulatory target. This language will require the local plans to tackle mobile sources and consumer behavior--notoriously difficult areas to regulate.

The Safety Net Program is intended to be used in the rare circumstance where a source lying outside a selected geographic area is clearly shown to be single-handedly causing the ambient air to exceed the benchmarks for one-or-more air toxic(s). This exceedance must occur outside the source's property. If such a source is identified, the Safety Net Program allows DEQ to require that source to perform a risk assessment. If the source-specific risk assessment demonstrates that the source is not causing off-site exposures in excess of the acceptable risk level (again, excess cancer risk of one-in-one million and hazard quotient of one), then the source is excused from further action. If, however, the risk assessment confirms that the source is causing exposures in excess of the acceptable risk level, the source must assess its alternatives for decreasing ambient impacts below the benchmarks. The source then must either implement measures to decrease impacts below the acceptable risk level or determine and implement Toxics Best Available Retrofit Technology (TBART). If implementing TBART is insufficient to decrease impacts below the acceptable risk level, the TBART determination must be reassessed every five years (when the source's air permit is renewed).

The final rules include only minor changes to the Safety Net program in comparison to the proposed rule. In response to comments, DEQ broadened slightly the exemption for sources subject to a National Emissions Standard for Hazardous Air Pollutants (NESHAP) based on Maximum Available Control Technology (MACT). The proposed rule exempted these sources only if the NESHAP specifically address the air toxic for which a benchmark exceedance is identified. Because EPA has announced that it intends for the residual risk assessments for these source categories to include all the hazardous air pollutants they emit, DEQ eliminated this limitation. This change assures that NESHAP/MACT sources (except possibly areas sources that are not subject to residual risk assessments) will not be subjected to potentially redundant or contradictory Safety Net program requirements. Some commenters urged DEQ to expand this exemption to the Geographic Program, but DEQ rejected that concept.

The final rule also includes other exemptions for sources that are already subject to an emissions limit or control requirement as a result of modeling or risk assessment previously conducted under DEQ's old interim air toxics policy. Another exemption covers sources that are located in an area selected as a geographic area. Because DEQ lacks resources to select more than a few geographic areas, this latter exemption will apply in fairly few areas (such as the cities listed above). It will not apply at all until DEQ formally designates selected geographic areas, which is likely to take two years or more.

The source category subprogram has changed minimally since DEQ first proposed it in 2002. The source category subprogram allows DEQ to take emission standards developed as part of the geographic subprogram or the Safety Net subprogram and apply them to areas outside where an identified problem has been documented. This portion of the rules gives DEQ somewhat greater discretion in determining whether or not to propose new requirements. Although the rules do not firmly limit when DEQ can propose Source Category rules, they do require DEQ to consider: 1) whether the source category will be addressed by the other subprograms; 2) whether voluntary strategies would be effective; and 3) whether the category of source contribute to benchmark exceedances in multiple areas. In order to actually create new requirements in this subprogram, DEQ must go through the full rulemaking process, complete with public notice and comment and EQC adoption.

Probably the most immediate implications of this new program are that we are likely to see more air toxics monitoring around the state. As these monitoring results are published, we can expect an upwelling of public concerns and for the public to identify industrial facilities as the obvious scapegoats. This reaction may be exacerbated by the amount of time it will take for geographic plans to be developed, to be implemented, and to make a difference.

We also can expect wrangling as DEQ works to develop the new benchmarks. DEQ will likely find it hard to develop a broad based Air Toxics Science Advisory Committee that can afford to devote the time necessary to have meaningful input into these issues. Once that group begins its work, the benchmark setting process will create opportunities for various interest groups to lobby for generous or conservative benchmarks for their pollutants-of-concern and perhaps test DEQ's commitment to stick to sound science and moderate public policy.

The real struggle, however, will occur when DEQ appoints the local advisory committee for Portland and the committee grapples with the difficulties of controlling mobile sources and behavior of 'the masses'-of which we are all part. The local planning effort will resurrect timeworn proposals such as congestion pricing and other concepts to limit vehicle miles and will collide with the automobile lobby and aspects of the Oregon Constitution. The geographic scope and diversity of the Portland area also will create perplexing challenges. In the meantime, the public is likely to escalate its concern about air toxics generally and about specific sources, particularly given the amount of time before the program is likely to produce local plans that can start encouraging changes.

DEQ has taken a bold step in developing an air toxics program that will be built on documented (rather than theoretical) air toxic risks. This approach differs from many state and federal programs that give little, if any, consideration for risk. More importantly, the emphasis on development of local plans to address the full range of sources goes beyond what any other state or federal program has attempted. How well the program, DEQ, and the public can respond to these challenges remains to be seen.

FOR ADDITIONAL INFORMATION, CONTACT: Mark Morford, Stoel Rives LLP, 503/ 294-9259; Tom Wood, Stoel Rives LLP, 503/ 294-9396

DEQ CONTACT: Sarah Armitage, DEQ/AC,503/ 229-5186

Originally published in Oregon Insider, Issue #331, November 1, 2003.