JEROME -- Sempra Generation's quest to build a coal-fired power plant near Jerome ran into its first snag on Tuesday.

Local environmentalist Lee Halper filed an appeal of Jerome County Planning and Zoning Commission's decision to allow Sempra to build a meteorological tower -- an initial step in the permitting process for a coal-fired plant.

San Diego-based Sempra, acting under the subsidiary Idaho Valley LLC, would use the weather station to collect information about precipitation, wind speed and temperature in the area. The company also would monitor the level of existing air pollutants such as sulfur dioxide, nitrogen oxide, particulate matter and ozone -- pollutants linked to respiratory illness and environmental damage. This data will be considered when Sempra applies for its state air quality permit for the 600-megawatt coal-fired power plant.

During the May 23 public hearing on Sempra's permit, several residents requested that the commission require Sempra to monitor additional air pollutants such as mercury and ammonia. The commissioners did not stipulate additional monitoring but did require Sempra to pay for an independent agent to verify collected data.

Halper has appealed the planning and zoning commission's decision to the county commissioners. Halper alleges that the planning and zoning commission held an illegal executive session June 6 when the commission rendered its decision on Sempra's permit request. Halper also claims the commission failed to review adequately the 24-page document he presented -- a document the commission originally decided not to allow during the May 23 public hearing.

Phone calls to Jerome County commissioners were not returned before press time.

Times-News reporter Michelle Dunlop can be reached at 735-3237 or by e-mail at mdunlop@magicvalley.com.