The EPA has approved the Clean Air Plan for Houston developed in 2004 by the TCEQ to address compliance with EPA's 1-hour ozone standard. By taking this action, EPA is saying that it believes that by 2007 the TCEQ's efforts will have virtually eliminated high levels of ozone smog in the Houston region.

GHASP, Environmental Defense, Sierra Club and Public Citizen opposed this approval, and filed the only set of detailed comments on the plan. Industry also filed some comments as well but these were less extensive. It took the EPA over a year to respond to these comments.

During 2004, environmental groups (see attached) and a large number of other agencies, industry groups and companies commented to the TCEQ on its plan.

Chemical plants, refineries, power plants and other industrial facilities that hold air pollution permits are subject to state rules regarding emission events. Often referred to as upsets, emission events include air pollution released during malfunctions (accidents), maintenance activities, unit startups and unit shutdowns.