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Center for Biological Diversity, et al., v. EPA


Center for Biological Diversity, et al., v. EPA

On July 12, 2013, a federal court ruled in the Center for Biological Diversity, et al. v EPA case that EPA failed to provide legal justification to support deferral of greenhouse gas (GHG) permitting requirements for biogenic emissions. The U.S. Court of Appeals for the District of Columbia (D.C. Circuit) vacated EPA’s three-year Deferral Rule icon-pdf thereby creating uncertainty regarding the permitting requirements for biogenic sources, which include emissions from wastewater treatment processes and the combustion of biogas and biosolids – as well as to combustion of other biomass, such as agricultural and forest products.

However, in a separate consolidated federal lawsuit - Utility Air Regulatory Group (UARG) v. EPA icon-pdf - the U.S. Supreme Court ruled on June 23, 2014 that EPA is prohibited under the Clean Air Act (CAA) from regulating stationary sources via the Title V and Prevention of Significant Deterioration (PSD) programs based solely on GHG pollutants. Publicly owned treatment works (POTWs) will benefit from this decision because the vast majority are considered non-major sources under the CAA and potentially faced future Title V and PSD permitting due to GHG emissions generated onsite by burning of biogas and/or biosolids, process emissions, or other sources of GHG emissions. The Court’s decision will keep many POTWs out of the Title V and PSD programs altogether and allow others to narrow the scope of their Title V obligations.

NACWA has long advocated to exempt POTWs from CAA permitting requirements based solely on GHG emissions, both in separate federal litigation and with EPA. NACWA is a member of the Biogenic CO2 Coalition whose objective is exclusion of short cycle carbon dioxide (CO2) emissions from CAA permitting programs. The Supreme Court ruling is consistent with NACWA’s advocacy to avoid GHG permitting for POTWs, and the Association is pleased with the outcome.

In June 2010, EPA released its GHG Tailoring Rule applying permitting regulations to large stationary sources of CO2. EPA did not exclude biogenic emissions, which occur as a result of combustion or decomposition of biological materials and are considered part of the natural carbon cycle. Without an exclusion, the CO2 emissions from wastewater treatment process, as well as combustion of biosolids and biogas, will be subject to CAA PSD and Title V permitting programs. NACWA and other industries impacted by the rule objected, emphasizing the carbon neutrality of these emissions, which led EPA in January 2011 to institute the three-year deferral while it conducts scientific analysis and develops rulemaking to specifically address these emissions. Environmental groups filed a legal challenge to the deferral via the Center for Biological Diversity case. NACWA filed an amicus brief in the case explaining why biogenic emissions from POTWs are different in nature, noting the short carbon cycle associated with human waste and the unavoidable nature of the emissions, which would occur regardless of POTW processing. The brief also emphasized the hardship that would occur if POTWs were forced to comply with the permitting requirements.

Although the D.C. Circuit struck down EPA’s biogenic exemption in its July 2013 decision in the Center for Biological Diversity decision, the ruling did not take immediate effect.   Because a number of separate legal challenges had been filed to EPA’s underlying efforts to regulate GHG emissions from stationary sources – all of which were ultimately consolidated into the UARG case -- the D.C. Circuit stayed its decision on the biogenic exemption pending resolution by the Supreme Court of the UARG case.  It is likely that, because of the Supreme Court’s ruling in UARG, the decision in Center for Biological Diversity will now be moot and there will be no further proceedings. 

In the UARG decision, the Supreme Court reviewed the Tailoring Rule and how EPA sought to regulate GHG emissions for stationary sources under the CAA. The Court affirmed EPA’s authority to regulate GHGs from stationary sources but rejected the way EPA proposed to implement that authority. The Court held that EPA cannot impose Title V or PSD permitting requirements on stationary sources based only on emissions of GHGs. At the same time, the Court ruled that sources already subject to PSD permitting requirements (so-called “anyway” sources because they are required to undergo PSD permitting “anyway” for conventional, non-GHG emissions) could be required to include greenhouse gas emissions in their best achievable control technology (BACT) analyses.

POTW Title V Permit Determinations
The Supreme Court’s decision will affect the number and scope of Title V permits required for POTWs. For the vast majority of POTWs that are not already considered major source emitters under Title V, this ruling prohibits EPA from using GHG emissions alone to require that a POTW obtain a federal operating permit. Whether the GHGs are biogenic is now irrelevant because all GHGs are excluded from the major source determination for Title V purposes. The decision will not affect the small number of POTWs that are required to obtain Title V permits because they are currently major sources for non-GHG pollutants.

The Court’s decision may also affect the scope of Title V permitting for the POTWs required to obtain a Title V permit due to the Sewage Sludge Incinerator (SSI) rule. POTWs that operate incinerators for biosolids management have been required to apply for a Title V permit as one of their new obligations under the SSI rule. For POTWs that did not previously have a Title V permit, the SSI rule allows the permitting authority to issue a Title V permit that covers only the SSI unit. Prior to the UARG decision, GHG emissions in excess of the major source threshold would have been a justification for issuing a facility-wide Title V permit. After the Court’s decision, these POTWs would be justified in asking the permit authority to limit the scope of the Title V permit to their SSI units as allowed under the SSI rule. Note, however, that some states may choose to proceed with facility-wide Title V permitting on the basis that they have the discretion to be more stringent than what federal rules require.

POTW Prevention of Significant Deterioration (PSD) Permitting
The Supreme Court decision also narrows the circumstances when POTWs will trigger major source PSD permitting obligations. PSD applies only to major stationary sources. Under the UARG decision, POTWs can no longer be considered major PSD sources based on their GHG emissions alone. The Court determined that the PSD program will only regulate GHG emissions at existing sources that are major for a non-GHG pollutant and for which PSD is triggered by a modification causing a significant net emission increase of non-GHG pollutants.

Very few POTWs in the country are major PSD sources based on non-GHG emissions. Fewer still will undergo modifications that trigger PSD based on a significant net emission increase of non-GHG pollutants. However, to the extent a POTW triggers PSD anyway based on its non-GHG emissions, the Court found that EPA could require the source to apply BACT to GHG emissions resulting from the PSD project. But the Court also affirmed EPA’s discretion to set a de minimis level for GHGs below which a project would not be required to apply GHG BACT. More agency rulemaking on this issue is expected in the future to establish this necessary justification. NACWA will work closely with EPA to set a de minimis level that would further exclude POTWs from PSD requirements for GHGs.

State Regulations May Be More Stringent
The Supreme Court decision did not address whether states could be more stringent in their treatment of GHGs.  Thus, the decision may not be self-executing in states that have adopted the Tailoring Rule into their state rules.  States may need to act to remove their Tailoring Rule provisions to implement this decision.  States may also need to consider how biogenic GHGs are treated in their regulations.  POTWs should consult with their state regulators to determine the status of permitting requirements in their state.

POTWs benefit from the U. S. Supreme Court’s UARG v. EPA decision in the following material ways:

  1. The Court decision eliminates the risk that GHGs will increase the number of POTWs subject to Title V and PSD permitting, without further debate over whether biogenic sources should be exempt or not. Unless POTWs are already considered CAA major sources subject to Title V and PSD for conventional, non-GHG emission, they do not have to worry about new permitting requirements based solely on GHG emissions from onsite processes such as burning of biogas and/or biosolids, process emissions, or other sources of GHG emissions.
  2. By eliminating GHGs as a trigger for Title V permitting, POTWs obtaining new Title V Permits under the SSI rule for their incinerators are better able to avoid facility-wide Title V permits and limit their federal operating permit burden to their SSI units only.
  3. While the Court affirmed EPA’s authority to impose GHG BACT on the major sources that trigger PSD based on non-GHG emissions anyway, POTWs will rarely trigger PSD permitting when GHGs are excluded from the applicability determination.

POTWs should check with their state regulators to determine how their state is implementing the decision and if their state is imposing more stringent requirements related to GHGs. NACWA will continue to track developments on this issue and report to the membership as appropriate. Members with any questions about the decision and its impact should contact Nathan Gardner-Andrews at  This e-mail address is being protected from spambots. You need JavaScript enabled to view it  or Cynthia Finley at  This e-mail address is being protected from spambots. You need JavaScript enabled to view it .



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