Posted on July 10, 2013 by Charles Nestrud
In April of 2013 the Arkansas legislature put an end to the ad hoc policy of implementing the NAAQS through stationary source permitting based upon source specific NAAQS modeling. The Arkansas legislature did not need a crystal ball to predict the chaos that was about to occur when the new NAAQS (PM2.5, one hour SO2 and one hour NO2) were swept into the existing Arkansas regulatory program. Arkansas’ environmental agency, the Arkansas Department of Environmental Quality (ADEQ) has relied upon its stationary source permitting program to implement the NAAQS for years, as opposed to relying upon state implementation plan (SIP) development. ADEQ has required every permit applicant to submit air dispersion modeling, and thereby demonstrate that the source will not cause a NAAQS violation. By comparison, EPA generally requires only PSD permit applicants to submit NAAQS dispersion modeling, and requires the states to otherwise address NAAQS compliance through their SIPs.
When Arkansas’ SIP permit procedures were last updated in 2000, minor (non-Title V) sources, and “minor modifications” at major sources were not required to undertake NAAQS modeling. Arkansas’ policies regarding NAAQS modeling were generally in sync with the Clean Air Act and most other states. Over the ensuing years regulatory creep expanded Arkansas’ NAAQS modeling program to the point that nearly every stationary source permit application was involved. ADEQ permit engineers required NAAQS dispersion modeling for minor sources, for minor mods at major sources, and then for any permit renewal—even no change renewals, “just to make sure that the source is still OK.” For example, a facility that had operated in full permit compliance for decades, without any modifications, could face permit renewal problems for no reason other than background conditions or recent meteorological data changed the NAAQS modeling results. Suffice to say this development was unpopular, making permitting expensive, time consuming, and uncertain.
The uncertainty was predicted to become chaos in September of 2012 when ADEQ proposed to drop the new NAAQS into its existing SIP. ADEQ’s “plan” was that the new NAAQS would also be implemented through stationary source permitting, including ADEQ’s expansive NAAQS modeling policies. Of particular concern is the PM2.5 standard, which, at 12 ug/cm3, is already near or exceeded by the background levels measured at the majority of the ambient monitoring stations throughout the state—background that is rarely, if ever, the result of any stationary source activity, but more likely the result of rural road dust and other non-stationary sources.
It became apparent to the regulated community that each permit review following adoption of the new NAAQS would generate ad hoc findings of modeled exceedances of the new NAAQS. By implementing the NAAQS through stationary source permitting rather than SIP planning, ADEQ eliminated any evaluation of regional cause and effect, and precluded any consideration of comprehensive solutions that involve all contributing sources. Under ADEQ’s “plan,” the unwitting permit applicant is forced to stand alone and face the consequences of a failed NAAQS modeling exercise. Concerns raised by the regulated community fell on deaf ears.
The Arkansas legislature stepped in, and in April of 2013 it enacted Act 1302, which required ADEQ to stop “protecting the NAAQS” by requiring stationary source permit applicants to undertake dispersion modeling, except in enumerated circumstances. Act 1302 prohibits ADEQ from using modeling for stationary source permit decisions or requiring retrofit pollution control technology. With the exception of PSD and other limited situations, dispersion modeling can only be used when there is a source or pollutant-specific SIP requirement. The Clean Air Act requires states to develop a SIP “for maintenance and protection of the NAAQS,” and Act 1302 requires ADEQ to implement the NAAQS as required by the Clean Air Act. The legislature did not neuter the agency’s efforts to protect clean air (which was the agency’s unsuccessful lobbying position). The legislature just said quit implementing the NAAQS through ad hoc permit decisions based on source specific air dispersion modeling. The legislature told ADEQ to use its ambient monitoring network, area modeling, and other tools to evaluate NAAQS compliance, and where non-attainment occurs, do the comprehensive planning that is required by the Clean Air Act to address it. Act 1302 was carefully drafted to compliment the Clean Air Act, and serves as a good model for any state facing similar NAAQS implementation issues.
During the two months since Act 1302 has been the law in Arkansas the agency has gone through some needed growing pains. The proposed rulemaking to enact the new NAAQS in Arkansas is being re-evaluated in light of the requirements of Act 1302. Much of the regulatory creep that occurred over the past decade has been curtailed, such that minor sources, minor modifications and no change permit renewals are no longer being required to submit dispersion modeling or demonstrate NAAQS compliance.
There is nothing like the heavy hand of the legislature to bring reason back into agency decision making. It appears that ADEQ now recognizes (much like most other states) that modeling has its limitations, and these minor stationary source projects are not causing, nor are they likely to cause any NAAQS problems. There is still a lot of work to be done as the new NAAQS are adopted, and real SIP planning commences. But sometimes it takes a pre-emptive strike to get the process started on the right track.