In July 2008, a number of environmental groups filed suit against the Virginia Air Pollution Control Board over air permits issued for a coal-fired power plant, alleging, among other things, that state regulators improperly failed to conduct a pollution control analysis for carbon dioxide emissions at the Virginia City Hybrid Energy Center before issuing the permits. Earlier this week, Judge Margaret Spencer, a circuit court judge in Richmond, Virginia, ruled in favor of state regulators on the issue, upholding the board’s issuance of the facility's Prevention of Significant Deterioration (PSD) permit despite the absence of a CO2 emissions analysis. The ruling was not all bad news for the environmental groups, however, as the judge tossed out the plant’s maximum achievable control technology (MACT) permit due to an “escape hatch” provision based on mercury emission levels.