The Geysers
After overcoming legal, engineering challenges, SR project with Calpine works so well wastewater proves hot commodity

Article published Nov 29, 2004

© The Press Democrat.

A decade ago, predictions by Santa Rosa representatives that the city's wastewater would one day be a hot commodity were mocked by critics, who said officials were simply looking for someone gullible enough to take the unwanted effluent. Today, the once-scorned wastewater is being pumped to The Geysers, where Calpine Corp. uses it to generate electricity that earns the company $1 million annually.

It will be a year ago Thursday that Santa Rosa officials first flipped the switch on a novel system in which a 40-mile pipeline carries wastewater to The Geysers, where it is injected into the ground to maintain the life of the world's largest geothermal energy complex. Except for a wildfire that forced the system to shut down for three weeks in September, "Santa Rosa's system has been virtually flawless," said Dennis Gilles, vice president of geothermal for Calpine, the city's partner in the $250 million project.

Looking back, the fire was a minor inconvenience for a project that had to overcome a series of obstacles between its selection in January 1998 and its first day of operation Dec. 2, 2003.
In the end, the engineering challenge of forcing 11 million gallons of treated effluent a day 3,300 feet up the Mayacmas Mountains was secondary to resolving a dozen lawsuits and the uproar of communities infuriated by the disruption caused by construction of the project.

But the completed project continues to raise issues that threaten more controversy.
The injection of wastewater deep within the steam field that straddles the Sonoma-Lake county line has triggered a dramatic increase in low-level earthquakes at The Geysers. And projections are the four cities that are partners in the project - Santa Rosa, Rohnert Park, Cotati and Sebastopol - will eventually raise sewer rates and connection fees to finance system expansions to accommodate new growth and stricter discharge regulations.

Until that time, however, The Geysers project is expected to operate as planned, meeting both Santa Rosa's discharge requirements and Calpine's need to keep its geothermal energy operation alive.
And it is doing so without the community rancor that was a constant companion during the construction phase. Dick Hafner, whose winery and 100-acre vineyard abut the pipeline's route up Pine Flat Road, said his neighborhood's anger over the project has dissipated. "It's the construction that had us all growling. So far it (the project) has been working pretty well," he said.

Calpine officials agree, saying Santa Rosa's wastewater has breathed new life into The Geysers. By mid-2006, the company expects the effluent will allow it to produce 85 megawatts of electricity a day, enough to supply the residential energy needs of both Rohnert Park and Santa Rosa. The transfusion of wastewater deep into the 450-degree rock strata also is expected to prolong the productive life of the steam fields, which have been on a slow decline since the daily power output at The Geysers peaked at 2,000 megawatts in 1987. Today, it's less than half that.

Without wastewater to replenish the escaping steam, The Geysers would eventually dry up and die.
Gilles said the addition of Santa Rosa's wastewater should keep the steam fields economically viable for at least 30 years - the life of the contract between Santa Rosa and Calpine - and probably double that.
Bob Austin, who heads a crew of seven responsible for operating and maintaining Santa Rosa's end of the high-pressure transmission line and 16 three-story-tall pumps along the route, marvels at how well the system has worked. "For something this large and having pumped over 3 billion gallons so far, it's amazing how well it has operated," he said.

The highly automated system is so easy to operate that Austin can run the entire operation from his home with his laptop computer. Through late November, Santa Rosa had pumped almost 3.4 billion gallons of wastewater to The Geysers, a flow interrupted only by the fire and the summer reduction to assist farmers.

In fact, the system has worked so well in putting wastewater to productive use that Santa Rosa's storage ponds "are virtually bone dry," said Dan Carlson, Santa Rosa's utilities projects manager.
That's good news for the Russian River, which during most winters receives billions of gallons of the city's stored wastewater.

All of these benefits, however, have come at a price. The average Santa Rosa household will pay $6.70 a month, or more than $2,000 over 25 years, to pay off the $205 million the city spent on its portion of the project.

The cost of the pipeline has pushed the average Santa Rosa homeowner's sewer bill to $49.20 a month, the seventh highest in the state, according to a survey conducted last year by Black & Veatch Corp., an Irvine-based consulting firm.

In addition, the economic benefits for energy generation and the environmental benefits to the Russian River have come at a cost to farmers who rely on the city's effluent for irrigation. Because this year's dry spring increased farmers' irrigation needs, there was insufficient stored effluent to accommodate both farmers and Calpine. Calpine eventually agreed to reduce its summertime draw, providing an extra 3 million gallons a day to farmers, but the concession wasn't made until July and by then farmers had already suffered losses.
Kathy Reese, who owns the 500-acre Denner Ranch in western Sonoma County, said the cutback in wastewater forced her to close her dried-up pastureland to paying clients. To prevent similar emergencies in the future, Calpine and the city are nearing an agreement that would result in Calpine's taking less than 11 million gallons of wastewater a day in summer, while making up the difference in the winter when farmers have little need for supplemental water. The irony of the battle over wastewater isn't lost on Richard Dowd, chairman of Santa Rosa's Board of Public Utilities."Five years ago it would have been blasphemy to say this, but we don't have enough wastewater today to go around. We're at the point now we have to dole it out to different interests," he said. Revised growth projections for Santa Rosa and Rohnert Park indicate another 2.2 billion gallons of wastewater a year will be generated by 2020, and Santa Rosa is already researching additional disposal programs.

Dowd expects the competition for that wastewater to be stiff, particularly in light of indications from the state that it may not allow the county Water Agency to draw more fresh water from the Russian River.
The shortage could set up a water fight among Calpine, which wants more wastewater to bolster power production, farmers who have ongoing irrigation needs, and home builders who want new effluent uses that could free up potable water for new homes.

WASTEWATER TO STEAM

Monthly and average daily wastewater flows to The Geysers
(Millions of Gallons)
Monthly Daily
January 385.9 12.5
February 350.3 12.1
March 371.1 12.0
April 242.8 8.1
May 273.5 8.8
June 306.5 10.2
July 233.7 7.5
August 242.6 7.8
Sept. 99 3.3*
October 438.7 14.2
Nov. 406 14.5 (through Nov. 28)

*Pipeline was shut down for 21 days due to Geysers Fire.

SOURCE: SR Utilities Dept.

HOW IT'S DONE
The city of Santa Rosa's wastewater is stored in large holding ponds, left, which are almost a mile long.
A 40-mile pipeline carries 11 million gallons of treated effluent a day 3,300 feet up the Mayacmas Mountains to The Geysers. Tanks hold the wastewater before it is injected into the ground to maintain the life of the world's largest geothermal energy complex.