Mirant plants attract attention in Delta crisis

By Mike Taugher
Wednesday, March 15, 2006

A pair of Contra Costa County power plants that at one time killed tens of millions of fish a year are being scrutinized by researchers investigating potential causes of the ecological crash in the Delta.

The plants in Antioch and Pittsburg are cooled with water from Suisun Bay, which is an important habitat for rearing fish and the place where scientists think some of the main problems leading to the crisis might be found.

Although a consultant reported in 1979 that as many as 86 million smelt and smelt larvae were sucked into the two power plants each year, that was at a time when the now-aged plants were run much harder and there were more fish in the water. Those numbers included both Delta smelt, which are protected under the Endangered Species Act, and longfin smelt.

But what has happened since then is unknown because the plants' owner, Mirant Corp., has not provided information about the effects of the plants' operations. Scientists want to know how much water is drawn into the cooling systems, how many fish are in that water and how much the discharges are warming the bay's water.

"I want to get some data to really give me a sense of what's going on out there," said Chuck Armor, operations manager of the state Department of Fish and Game's Central Valley/Bay-Delta branch.

Despite delays in providing information, the company is now cooperating more with regulators as its Endangered Species Act permits expire, according to officials.

Officials say the company did not meet the conditions of the permits issued in 2002. Those conditions included a requirement for Mirant to install a screen to keep fish out of one of the power plants. If the screen worked, Mirant was expected to do the same at the other plant.

The conditions also required Mirant to monitor the number of fish being killed at the plants.

But Mirant never installed a screen and the U.S. Fish and Wildlife Service says that it appears the company never monitored fish killed at the intake pipes, either.

"As far as we know, that hasn't been done," said Fish and Wildlife Service spokesman Jim Nickles. "There is nothing happening that will reduce the impacts. We're definitely concerned about that."

Nickles said his agency is working with Mirant to draft another permit, but he could not comment on any possible enforcement actions in connection with the company's failure to meet the permit conditions.

In response to a series of specific questions asked by the Times, including queries about the lack of a fish screen and monitoring data about the number of fish killed at the plants, the company e-mailed a two-sentence response.

"Mirant Delta is committed to doing its part to protect the environment, while maintaining power system reliability for residents of the San Francisco Bay area. Mirant Delta is also working directly with all associated agencies to ensure the safety of wildlife habitats in the Bay," the company said.

The recent decline in populations of open-water Delta fish began in about 2001 or 2002 and represents a steep drop in what was already a decades-long general decline among Delta fish populations. Delta smelt, longfin smelt, threadfin shad and young-of-year striped bass all are at or near record lows.

Scientists say the cause of the problem is likely a combination of toxic pollution, invasive species that are competing for resources with native fish, and water pumping operations. One leading theory holds that invasive clams now carpeting the bottom of Suisun Bay are consuming the food needed by young fish. The clams, which arrived about 20 years ago in ship ballast from Asia, might be taking advantage of increased salinity in the fall when less water flows into the Delta.

Scientists say it is possible that, if the root of the problem is in Suisun Bay, the power plants could be adding to the problem.

Environmentalists and anglers, meanwhile, are especially focused on the massive pumping stations at Byron and Tracy that deliver water to the San Joaquin Valley and Southern California.

Jerry Johns, deputy director for the state Department of Water Resources, which operates the pumps at Byron, said the state and federal pumps are heavily scrutinized. But he notes that the Mirant pumps are almost completely ignored, even though the power plants take water out of more sensitive habitat.

"It seems that we have fish counts four times a day (at the state pumps), but we have zero information about how many fish are being entrained (sucked up) right in the heart of Delta smelt area," Johns said.

Combined, the two power plants' pumps can draw 3,240 cubic feet per second, or about 75 percent as much as federal pumps in Tracy that irrigate the San Joaquin Valley. It is unknown how much power those plants are generating and how much water they are using to cool them.

Mirant, based in Atlanta, bought the power plants from Pacific Gas and Electric in 1999. It reaped a windfall during California's deregulation experiment, but is now in bankruptcy.