SR plan to boost pumping to Geysers
New deal with Calpine for more wastewater for steamfields could save city $200 million
Published: Monday, July 30, 2007 at 3:41 a.m.
Last Modified: Monday, July 30, 2007 at 2:25 a.m.
Santa Rosa and Calpine have reached a tentative agreement to substantially increase the volume of wastewater pumped to The Geysers, potentially saving the city $200 million and eliminating discharges into the Laguna de Santa Rosa in some years.
Details will be outlined to the city Board of Public Utilities on Thursday. The board will be asked to recommend approval of the deal, which goes before the City Council on Aug. 14.
The city would provide 50 percent more wastewater for the steam-to-energy project and collect $300,000 a year toward pumping costs. No expansion of the pipeline would be required.
Carol Dean, a utilities board member, said it sounds like a "win-win situation" for the city, Calpine, Russian River residents and ratepayers in Santa Rosa, Rohnert Park, Cotati and Sebastopol, who use a regional sewage treatment system.
"We're all keeping our fingers crossed," Dean said. "It could save us a tremendous amount of money and it could be very good for the environment."
Calpine spokeswoman Katherine Potter said the plan fits with company plans to invest $200 million to stabilize and expand power production at The Geysers, the world's largest geothermal energy facility.
"Our hope is to enhance our production at The Geysers and this will allow us to do that," she said.
For the city, the deal could mean continuing to discharge excess wastewater into the Laguna de Santa Rosa rather than shifting its major discharge point to the Russian River to comply with strict new state water quality standards.
Pumping more effluent to The Geysers would reduce the amount discharged into the laguna by 60 to 70 percent on average per year, Deputy City Manager Greg Scoles said. In some years, he said, there would virtually be no discharge.
"This is pretty exciting stuff," Scoles said. "It could be really beneficial."
The city has estimated the costs of switching its discharge location and building storage reservoirs for wastewater at $120 million. A related wastewater storage plan is expected to cost as much as $100 million.
For Calpine, one of the nation's major energy-generating companies, the deal could boost revenue as it tries to emerge from bankruptcy proceedings it entered in 2005.
The Geysers is one of Calpine's most profitable assets and would become even more profitable if wastewater flows to the steamfields are increased by 50 percent, or nearly 2 billion gallons a year.
The city's current contract with Calpine calls for the city to supply it with 11 million gallons of wastewater a day, the equivalent of 4 billion gallons a year.
The wastewater is delivered by a 40-mile pipeline, built at a cost of $250 million. Calpine injects the water nearly 1.5 miles underground where it converts into steam and is pumped out to run electrical generators.
The project, intended to breathe new life into the declining steamfields while reducing wastewater discharges, began operating in December 2003.
In addition to eliminating the need for a new discharge point, Scoles said the ability to ship more effluent to The Geysers could eliminate the need to build storage ponds in the southwest and southeast quadrants of Santa Rosa.
"It's a high likelihood we could avoid adding more storage altogether," he said.
The reservoirs, at a construction cost of $38 million to $50 million each, have been proposed as part of a program to store winter wastewater for use during the summer for urban irrigation in areas that now rely on potable water.
Scoles said plans will go forward for expanding the city's urban wastewater irrigation system, at a cost of $119 million for a network of pipelines into the two quadrants. However, those plans are far from being solidified.
"It's a very expensive way to deal with effluent," he said. "But it's a conservation measure because you don't have to get (potable) water from somewhere else."
The Calpine deal would establish criteria by which the city would increase the amount of effluent it pumps to The Geysers over the next 15 to 30 years. In the outer years it could pump up to 5.5 billion gallons a year, an average of more than 15 million gallons a day.
The 30-inch pipeline that runs from the treatment plant can handle up to 20 million gallons a day, Scoles said.
The deal would require Calpine to pay Santa Rosa $300,000 a year, he said. That's about half of what it now costs the city annually to pump the wastewater from its regional treatment plant off Llano Road to the bottom of the Mayacmas Mountains 35 miles away.
Calpine pays the energy costs to pump it up the 3,300-foot slope to the steamfields.
How quickly the deal can be completed, however, remains the central question.
"We don't know how far or how fast negotiations can go because Calpine is still in bankruptcy," Dean said.
Calpine officials already have signed off on the deal, said Dennis Gilles, the company's senior vice president. Pending Santa Rosa's OK, final approval will be sought from the bankruptcy court on Sept. 11, he said.
Gilles said the wastewater deal is good for both sides.
"It will allow the city to send it to the Geysers rather than dumping it in the river and it provides predictability of delivery to us," he said.
You can reach Staff Writer Mike McCoy at 521-5276 or mike.mccoy@pressdemocrat.com.
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