Monroe County citizens have more than a passing interest in a court ruling last week that a U.S. Environmental Protection Agency lawsuit charging Vectren Energy Delivery of Indiana with violating the Clean Air Act can proceed. The outcome will have a direct impact on air quality in and around the Bloomington area.

Vectren's Culley Generating Station in Warrick County is one of several coal-fired power plants in the Midwest and South that EPA is suing for violating Clean Air Act provisions that prohibit major changes at old, polluting power plants without the installation of modern pollution-control equipment. The law anticipated that the requirement, known as New Source Review, would lead to the mothballing of dirty plants like Culley, which would be replaced by newer, less-polluting facilities.

EPA alleges that the plants it is suing, which include four in Indiana, made changes to their facilities without the sort of pollution-control improvements required by the Clean Air Act. Vectren argued that changes made at Culley in 1991 and 1992 did not increase pollution and therefore are not subject to NSR requirements. A federal judge last week ruled against Vectren and scheduled the case for trial on Oct. 16.

The EPA suits were brought in response to concerns from Northeastern states that chemical emissions from power plants in the Midwest were contributing to ground-level ozone in their states. In an effort to stave off federal action against the plants, Indiana and several states in 1995 formed the Ozone Transportation Assessment Group (OTAG), which studied the movement of ozone-causing chemicals.

Ozone, or smog, is formed when emissions from power plant smokestacks mix with summer heat and sunlight. It can cause serious breathing problems for the young, the elderly, and people with lung disease like emphysema or asthma. High ozone levels can be problematic for healthy people who work outdoors.

Bloomington citizens have no way of knowing how polluted their air is because the state of Indiana does not have the resources to monitor it. But the results of the 37-state OTAG group study, released in 1997, showed that ozone-causing chemicals from power plants can travel anywhere from 200 to 300 miles from their source.

Vectren's Warrick County plant is approximately 150 miles upwind of Bloomington.