The San Diego County Air Pollution Control Board moved on Wednesday (June 17) to allow the controversial new Pio Pico gas-fired power plant in Otay Mesa to increase periodic sulfur oxide emissions by as much as 10 percent.
The amendment to the county's preliminary approval was made "to increase the allowable maximum hourly heat input and power output of each combustion turbine by approximately 10%, to account for design changes to the turbines made by the manufacturer."
The Pio Pico plant, with its 300-megawatt generation capacity will also bring more pollution to an area that already hosts the 590-megawatt Otay Mesa Energy Center. The new plant is being built as a replacement for the aging Encina plant in Carlsbad, where another battle is being waged against a new gas plant.
The county says that while emissions could increase up to 10 percent while the plant is operating, there is no overall change in pollution because, as a "peaker" plant, Pio Pico only runs when there is demand on the grid. The plant has a maximum allowable emissions level per year, and as long as the plant runs less than it would have under the approved guidelines, net emissions don't change.
Environmentalists and neighborhood opponents have already argued that actual emissions will likely be higher than the cap set, noting that federal Environmental Protection Agency guidelines allow for a 41-minute window during startup and shutdown where total allowable pollution is as much as five times higher than the baseline measurement. With a gas peaker plant, the facility could be switched on and off up to 500 times per year.