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IDEM Releases Interim Recreational Closure Levels for Direct Contact to Soil Exposure Scenario

04.01.2010

On February 11, 2010, the U.S. EPA proposed to end U.S. EPA’s longstanding policy that allows sources to demonstrate compliance with the prevention of significant deterioration (“PSD”) requirements for PM2.5 by using PM10 as a surrogate.

The policy began shortly after the U.S. EPA established a national ambient air quality standard (“NAAQS”) for PM2.5 in 1997. After promulgation of the new NAAQS standard, the U.S. EPA recognized that there were “significant technical difficulties” that existed with respect to PM2.5 implementation and that due to these difficulties the U.S. EPA would allow PM10 to be used as a surrogate for PM2.5 in meeting PSD requirements until the difficulties could be resolved. See, Interim Implementation for the New Source Review Requirements for PM2.5. (John S. Seitz, U.S. EPA, October 23, 1997). The U.S. EPA has since promulgated its PM2.5 implementation rules in a piecemeal fashion.

The first PM2.5 implementation rule, promulgated on April 25, 2007, contained the requirements for attainment dates, SIP submittals, and reasonable further progress, but did not include any NSR implementation provisions. On May 16, 2008, the U.S. EPA issued its rule entitled “Implementation of the New Source Review (NSR) Program for Particulate Matter Less Than 2.5 Micrometers (PM2.5)”, which finalized some of the elements needed for implementation of the NSR program for PM2.5, such as the major source threshold, significant emissions rate and offset ratios. This rule did not, however, include some of the elements needed to fully implement the NSR program such as PSD increments, significant impact levels (“SILs”) and significant monitoring concentrations. These omitted elements were set out in a proposed rule on September 21, 2007, but have not yet been finalized.

The preamble to the May 16, 2008 rule provides that PM10 may be used as a surrogate until the U.S. EPA has finalized all elements of the implementation rule. Further, the 2008 rulemaking contained two provisions relating to the transition to the use of PM2.5. First, it contained a “grandfathering provision” under the Federal PSD program which allowed PM10 to be used as a surrogate for PM2.5 for permit applications submitted before the July 15, 2008 effective date of the rule. Second it contained a provision allowing states three years from the date of publication of the rule to submit revised state implementation plans (“SIPs”) for regulating PM2.5 and, during the transition period, allowed states to continue to use U.S. EPA’s 1997 guidance by which a PSD analysis based on PM10 can be used as a surrogate for analysis based on PM2.5.

On February 11, 2010, acting on a petition for reconsideration, the U.S. EPA proposed to repeal the "grandfathering" provision and to end the use of the PM10 surrogacy policy in SIP-approved states. 75 Fed. Reg. 6827 (February 11, 2010). The U.S. EPA states that this proposal will affect new or major modified sources in SIP-approved states that have not yet received a final and effective permit authorizing the source to commence construction and that, if the proposal is finalized, new or major modified sources would thereafter be required to conduct permit-related analysis on PM2.5 rather than PM10. U.S. EPA states that it is not proposing that the repeal of the surrogacy policy apply retroactively to sources that have already obtained their PSD permits. Id. at 6628. 

The U.S. EPA justifies its proposed repeal of the surrogacy policy by citing to various court decisions which have held that a surrogate may only be used when it has been found reasonable to do so. The U.S. EPA states that the permitting record for any permits that continue to use the surrogacy policy must fully support the use of PM10 as a surrogate for PM2.5 and would need to address the differences between PM10 and PM2.5 and “demonstrate that PM10 is nonetheless an adequate surrogate for PM2.5.” Additionally, the U.S. EPA states that "a source or permitting authority seeking to rely on the PM10 surrogacy policy should identify any technical difficulties that exist to justify the application of the policy in each specific case." Id. at 6831-6832. However, the U.S. EPA states that the technical difficulties in the application of the PM2.5 standard have been "largely resolved to a degree sufficient for the owners and operators of sources and permitting authorities to conduct meaningful permit-related PM2.5 analyses." 

Finally, the U.S. EPA addresses the impact of ending the surrogacy policy in SIP-approved states. The U.S. EPA recognized that the use of the surrogacy policy in SIP-approved states was intended to allow states time to update their state laws and make their SIP submissions. In the proposed rule, the U.S. EPA states that this additional time may not be necessary as many states already have the legal authority in their existing SIPs to address PM2.5. For example, the U.S. EPA states that most states have adopted U.S. EPA's definition of "regulated NSR pollutant" allowing PM2.5 to be regulated because it is a pollutant for which a NAAQS has been established. Id. at 6834. Additionally, the U.S. EPA states that the lack of a significant emission rate for PM2.5 should not preclude states from implementing a full PM2.5 program as most states, including Indiana, have adopted U.S. EPA's definition of "significant emissions rate" which states that, for pollutants in which a significant emission rate has not been established, any increase is deemed significant. Id.

The U.S. EPA argues that these provisions should provide states the legal authority needed to implement the PM2.5 program. The U.S. EPA recognized that the “most significant implication of [the use of these existing provisions] may be that some sources making modifications that increase PM2.5 emissions in amounts less than 10 tons per year may have to undertake additional PSD review that would not be required” if the state's SIP were amended to include the significant emission rate established in the May 2008 final rule. Id. However, the U.S. EPA did not address the impact of the other regulatory elements missing from the 2008 rule needed to fully implement the NSR program such as PSD increments, SILs and significant monitoring concentrations.

Any Indiana sources wishing to take advantage of the PM10 surrogacy policy will need to act quickly in order to get the project permitted before the rule takes effect and should be prepared to fully justify its continued use of the surrogacy policy.

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