CHULA VISTA -- The California Energy Commission has kicked off a yearlong public review of a plan to replace the South Bay Power Plant with a smaller, more efficient -- and, by some standards, cleaner -- facility.

If the plans are approved, the new plant could be up and running by 2010.

In June, LSP South Bay, which holds the lease on the plant, submitted a proposal for rebuilding the power plant. The company wants to replace the bulky plant, which sits on 115 acres of San Diego Port District land, with a facility built with lower smokestacks on a 13-acre site south of the existing plant. The removal of the old plant would free up valuable bayfront land for redevelopment, a priority for Chula Vista.

The new plant would have nearly as much power generation capacity as the 46-year-old facility but would generate power more efficiently with less pollution, the company said.

The state commission hosted a public hearing and bus tour of the new site yesterday. About 50 people went on the tour and more than 100 attended a hearing in the Chula Vista library.

Yesterday's hearing was the first of several public forums that will be held in the coming year to take comments on the power plant replacement project. The California Energy Commission could vote on the project as early as August.

Discussions at the hearing centered on how the new plant will affect air quality. Power plant smokestacks release particulate matter into the air. The tiny particles lodge deep in the lungs and are linked to asthma, bronchitis and other health problems.

Andrew Trump, a project director for LSP, displayed charts showing annual air emissions from the existing power plant.

Trump said the South Bay Power Plant's emissions, which create particulates, have dropped from about 5,800 tons in 1981 to 200 tons in 2005. The plant switched from fuel oil to natural gas and made technology improvements to cut emissions. The plant also now operates well below capacity.

LSP's proposal says the new plant would keep air pollution at or below the current emissions level of "a few hundred tons" while producing more than twice the energy currently generated at the South Bay Power Plant.

"We think in total that's a very positive approach on air quality," Trump said.

Laura Hunter, director of the Environmental Health Coalition, testified at the hearing that the proposal doesn't do enough to reduce air emissions. She criticized the plan to generate as much pollution as the existing plant. "We're not just trying to keep the status quo," Hunter said. "We're going to try to get some improvement here."

Hunter noted that while more power would be produced, the air pollution would continue to be concentrated in the neighboring community, which is disproportionately poor.

"When does this community get clean air if we don't require new power plants to be cleaner than existing ones?" she said.

The Environmental Health Coalition is suggesting alternatives, including off-site power production instead of a new power plant, or a smaller plant that doesn't use duct-firing.

The group also wants to see sustainable power production, such as solar power, incorporated into the project.

Hunter praised one aspect of LSP's power plant proposal, which would no longer require the use of San Diego Bay water for cooling. Environmentalists say that the South Bay Power Plant is damaging marine life by sucking in seawater, heating it and then spewing it back into the bay. The new plant would be air-cooled.

Also yesterday, LSP South Bay's parent company, LS Power Group, announced an agreement with Dynegy of Houston, Texas, to combine assets. The companies are forming a joint venture to pursue development projects such as the replacement power plant.