Client:
City of Santa Rosa, California

Project Value:
$187 million

Project Duration:
1993–2003

Parsons Services:
Preliminary design for all alternatives; Environmental Impact Report (EIR) and Environmental Impact Statement (EIS) preparation

Geysers Project Map

The Mayacamas Mountain range is a rugged area in Sonoma County, California. It saw little human intrusion before the 1850s when a hunter in pursuit of a grizzly bear discovered a menacing collection of hissing fumaroles and bubbling hot springs. In a misnomer that remains to this day, he called the area The Geysers.

The Geysers were first tapped for steam production in the 1920s and reached peak electrical production in 1987, when it produced enough electricity to serve the daily needs of 1.8 million people. At that time, the steam from the field began a gradual decline as it was mined for electricity generation. Today, The Geysers remains the world’s largest geothermal steam field, producing 850 megawatts of electricity.

Seeing The Geysers steam field decline, the Santa Rosa Subregional Reclamation System needed a new “weather independent” disposal system for recycled water that would meet the requirements of the Regional Water Quality Control Board, protect the Russian River and other local waterways, and work in tandem with the successful use of recycled water for irrigation.

After wastewater spills in 1985, Santa Rosa leaders and the Board of Public Utilities began the search for a long-term solution. After two Environmental Impact Reports/Statements (EIR/EIS) failed between 1986 and 1991, the city hired Parsons and initiated a completely new planning and environmental process to identify and weigh all solutions through extensive public involvement. The new environmental process began in 1993.

Parsons began by conducting an extensive public involvement program throughout Sonoma County. Thousands of interested parties received project information and details about alternative plans and water quality issues. A project database enabled over 4,000 property owners, residents, public officials, emergency services, schools, hospitals, and affected agencies to stay up to date on project progress. Moreover, a website dedicated to the project EIR, design, and construction informed people of events and important public meetings and made key reports and studies available.

Cooling towers from geothermal plant

By 1997, Parsons had looked at as many as 134 alternatives, provided preliminary designs for 13 alternatives, and completed the primary EIR/EIS. One attractive alternative was the Geysers Recharge Project, which would pump tertiary treated water from the Subregional Reclamation Plant 40 miles to The Geysers steam field to recharge the field and generate electricity. The city’s selection of the Geysers Recharge Project in 1998 led to a further two years of pipeline alignment studies, four supplemental EIRs, 16 addenda, and many lawsuits, all of which were decided in the city’s favor.

The chosen project involves constructing 48-inch and 30-inch diameter underground pipes for 40 miles, beginning at Santa Rosa’s Laguna Treatment Plant and continuing to the base of the Mayacamas Mountains. The pipeline runs beneath city streets, county roads, city farms, and private properties, and it makes two passes under the Russian River with tunnels up to 90 feet deep and 900 feet long. It traverses the difficult terrain of the steep and winding Pine Flat Road, where the water is boosted uphill over 3,000 vertical feet by three large pump stations, transporting it to a terminal storage tank on a ridge of the Mayacamas Mountains. From there, Calpine, owner of the geothermal generating facilities, built another 18 miles of pipe, a pump station, and tank to feed the recycled water to eight injection wells having depths of 4,000 to 11,000 feet. At this depth, the water is heated naturally and produces a clean dry steam that drives turbines in nearby electrical power plants—an environmentally friendly, reliable, and renewable energy source.

Construction to terminal tank	Pipe laid through Audubon Sanctuary

Planning, construction, and post-construction all placed great emphasis on protecting the environment. Parsons evaluated all project aspects for construction methods and pipeline alignments that would minimize property and environmental impacts. Special design concerns involved protecting water quality, trees, and sensitive plants along the pipeline route; the potential effects on wetlands and wildlife; and the effect of a five-mile-long segment of pipeline through an Audubon Wildlife Sanctuary. Once construction began, a field team of environmental inspectors helped ensure compliance with EIR and regulatory agency conditions imposed on the project.

In November 2003, the Geysers Recharge Project began pumping 11 million gallons of highly treated wastewater per day to The Geysers steam fields. In an era calling for multiple wastewater reuse and disposal options combined with environmental stewardship, the project balances user needs and environmental responsibility. The value of the project becomes even more evident as today’s state and federal environmental regulations become tougher, and the future holds the prospect of even stricter standards.

This project has received praise as a public works project that benefits the community and the environment. Its added economic benefit is the extended life of the steam field, which continues to be a major source of property taxes, employment, and economic activity in Sonoma County. Partnering with Calpine allows the city to share capital and operating costs. By injecting recycled water to replenish underground steam wells, the city of Santa Rosa has established a safe, clean, and environmentally advanced way to reuse recycled water.

Piping for steam transport to the generating plant

The Geysers Recharge Project offers many ongoing benefits to the community and the environment including:

• Reduces annual discharges of recycled water into the Russian River by about 60% or 1.5 billion gallons, protecting the river from excess discharges during winter months.

• Partially replenishes the steam field and increases electrical output by about 85 megawatts, enough to meet the energy needs of 85,000 households.

• Produces renewable green power from geothermal steam, one of the most environmentally friendly forms of energy production. At its anticipated additional output of 85 megawatts, carbon dioxide is reduced by 570 million pounds and nitrous oxides by 253,000 pounds annually over that of natural gas-fired power plants.

• Provides expanded long-term water reuse opportunities that include agricultural needs in the future, thus possibly conserving the Russian River’s limited water.

The Geysers Recharge Project provides one-third of the alternative energy being generated in California. Since the heat source is virtually unlimited, the introduction of additional water can recharge the steam field and extend its life for more than 20 years. Thus, the Geysers Recharge Project solves two significant problems—one of insufficient water, the other of too much.

The Geysers Recharge Project will accommodate growth in Santa Rosa through about 2010. Parsons is now providing environmental review services to the city to accommodate the growth of its wastewater reclamation system through 2020 while responding to strict new water quality regulations.

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