MIRANT CORP. 's plan to build a huge new power plant at the foot of Potrero Hill has recently suffered serious blows. The San Francisco Board of Supervisors voted 10-0 – with Gavin Newsom absent – to oppose the plant expansion, and within a week of this vote Mirant filed for bankruptcy. While only the California Energy Commission has the silver bullet to officially kill Mirant's enormous white elephant, the city's actions, and basic economics, have brought the company to its knees.

But with Mirant not quite dead, San Francisco now faces the possibility that the city will build three or four smaller power plants, known as combustion turbines, in Potrero, most likely at historic Pier 70. Although a final decision has not yet been made, as part of a deal with the state, the city needs to secure sites for these plants by the end of the year or lose the valuable generators entirely.

Southeast San Francisco has suffered from excessive power plant-related polluting air emissions for decades. Mirant's Potrero plant and Pacific Gas and Electric Co.'s Hunters Point plant are old, inefficient, and environmentally unacceptable. It's time for them to close.

Current forecasts of San Francisco's energy demands, combined with in-city transmission upgrades and ongoing energy-efficiency and renewable-generation (e.g., solar) programs, indicate that the Hunters Point plant could be closed by 2005 without additional in-city generation. It's also plausible that Potrero's largest unit could be shut down by 2008 if more investments are made in transmission, demand reduction, and small-scale (one megawatt) generation.

However, neither the state nor the city sees it that way. The Independent System Operator, the agency responsible for protecting against blackouts, currently insists that all four C.T.s be sited in San Francisco before just the biggest part of the Hunters Point plant is closed. The city, in turn, is anxious both to close the plant and to find an acceptable place for the C.T.s.

Because the existing transmission system is "wired for injustice" – planned around the Potrero and Hunters Point power plants – there's only a handful of economically feasible locations for the new plants. Fifth and Jesse Streets can take one. The Embarcadero could also take one, but transmission constraints would reduce available supplies by 20 percent or more. Hunters Point works but is unacceptable because of environmental justice concerns.

And there's Potrero. But where exactly in Potrero, how many plants, and what other polluting sources will be reduced in return?

Pier 70 and the associated waterfront represents an economically valuable asset to our community and the entire city. Squandering it on a few power plants is shortsighted. Much better would be to do what it takes to gain control of the existing Potrero power plant, preferably by pushing Mirant off the property entirely. If not, Pier 80 is a possible location. And the San Francisco International Airport may be a good place for two of the C.T.s.

Decisions made over the next three months will be with us for the next three decades. We've already suffered through a round of disastrous energy policies. Let's not make more mistakes. Hunters Point needs to close today, and Potrero should shut down by 2008. Any additional generation should be sited extremely carefully, and the emissions from these plants fully mitigated.

Mostly ignored by the rest of the city, Potrero and Bayview-Hunters Point have been fighting a battle against multiple polluting nasties for decades. The time has come for other San Franciscans and our political leaders to join the fight. We may be willing to take a couple of C.T.s for the good of the city and to support public power. But we're not willing to welcome every bad thing that comes our way simply because it's easier for everyone else to look the other way.