Sierra Club v. Wyoming Department of Environmental Quality
251 P.3d 310
Wyo.2011Background
- DEQ issued an air quality permit for Medicine Bow's coal gasification/liquefaction plant and supplying underground mine near Medicine Bow, Wyoming.
- Sierra Club appealed to the Wyoming Environmental Quality Council, which granted DEQ and Medicine Bow summary judgment against Sierra Club.
- District Court certified the appeal to the Wyoming Supreme Court, which affirmed the Council's decision.
- Dispute centered on whether sulfur dioxide PTE should include malfunctions and cold-start emissions and whether BACT applied to flare emissions.
- Additional issues involved whether PM2.5 could be addressed via PM10 surrogate and whether fugitive PM emissions required modeling.
- Wyoming regulations require PTE and BACT analysis, and modeling or alternative approaches may be used for fugitive emissions.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether cold starts/malfunctions must be included in PTE | Sierra Club: include malfunction/cold-start emissions in PTE. | Sierra Club: emissions excluded by DEQ; PTE should be larger. | No; DEQ's exclusion proper; PTE based on normal operations. |
| Whether BACT applies to flare emissions during cold starts and malfunctions | Sierra Club: require BACT for flare emissions; SSEM plan not equivalent to BACT. | DEQ: BACT satisfied via design/work practices; SSEM plan minimizes emissions. | BACT not limited to numeric limits; plan deemed equivalent or adequate. |
| Whether PM2.5 compliance can rely on PM10 surrogate during transition period | Sierra Club: require permit-specific reasonableness for surrogacy; Trimble controls retroactivity. | DEQ/Medicine Bow: PM10 surrogate allowed during EPA transition; no permit-specific issue. | Trimble not retroactive; surrogate policy upheld for Medicine Bow. |
| Whether modeling fugitive PM emissions was required for 24-hour standards | Sierra Club: DEQ must model short-term fugitive emissions. | DEQ: modeling not required; use alternative approaches and long-term modeling. | Council/agency did not err; no requirement to model short-term fugitive emissions. |
| Whether DEQ’s overall permit decision complies with WAQSR and EPA guidance on surrogates, modeling, and SSEM | Sierra Club: agency misapplied EPA guidance and Wyoming rules. | DEQ conducted reasonable, documented determinations; relied on engineering judgment. | Wyoming Supreme Court affirmatively upheld the permit approval. |
Key Cases Cited
- Powder River Basin Resource Council v. Wyoming Dept. of Environmental Quality, 226 P.3d 809 (Wyo. 2010) (de novo review of agency summary judgments; EPA guidance persuasive)
- Alabama Power Co. v. Costle, 636 F.2d 323 (D.C. Cir. 1979) (PTE contemplates normal operation, not worst conceivable operation)
- Louisiana-Pacific Corp. v. United States, 682 F. Supp. 1141 (D. Colo. 1988) (PTE includes emissions during normal operation; not worst-case operation)