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CREATIVE SOLUTIONS Limitations on the options for disposing treated water also can produce creative water recycling solutions. Oftentimes, disposing of Ireated water can be problematic, particularly for inland areas. Two regions, Lake County and Santa Rosa, have devised innovative schemes to address the problem. ~-- Landscape irrigation (above) and car washes (belmv) are two examples of recycled wafer uses in the Irvine Ranch Water District. In the early 1980s, Lake County Sanitation District realized that a new dis- posal method was needed to handle the increasing treated water discharges from growing communities. At the same time, the dis- trict was facing a second problem: the nearby reser- voir which supplied water to the electricity-producing, 6,000 feet to 10,000 feet deep, Geysers geothermal steamfield, was drying up. A public-private partner- ship of Geysers operators and the county sanitation district developed a plan to recharge the Geysers with the surplus treated effluent. In October 1997, the first recycled water-la-electric- ity system in the world began operation. The $45 million project sends nearly 8 mgd of treated water through a 26-mile pipeline and injects the waler into the steam reservoir that feeds the Geysers. The effluent-derived steam is estimated to generate about 70 megawatts of electricity a year - enough to supply 70,000 homes. 16 Like Lake County, the city of Santa Rosa (located north of San Francisco) is developing a project to send treated water to the Geysers steamfieid. The tertiary treatment facility in Santa Rosa treats 19 mgd of wastewater with plans to expand their capacity to 27 mgd in 20 years. During the summer, about half of the treated water produced annually is used to irrigate 5,900 acres of farmland. Conversely, during the rainy season, the demand for recycled water drops oft, creating surplus treated water. Unlortu- nately, reclaimed water storage is limited and there are restrictions on Ihe amount of treated effluent that can be discharged to the Russian River, the treatment facilily has been unable to meet the water disposal requirements assigned by the regional water quality control board. The city investigated several possible solutions to the problem including increasing allowable discharges into the Russian River (Santa Rosa is currentty limited to 1 percent of the river's flow); expanding the amount of land irrigated; or pumping treated water to the depleted Geysers geothermal steamfield. Increasing the amount of irrigation with reclaimed water would have required additional storage reservoirs on farmland. This option was eventually dropped because of few willing sellers of farmland and limited interest in irrigating with reclaimed water. (In a show of support for the project, several farmers interested in using recycled water surrounded City Hall with tractors to protest export of the recycled water to Ihe Geysers.) Santa Rosa opted 10 proceed with a plan to send its treated water to recharge the electricity- producing Geysers. Under the proposed $132 million dollar project, approved by the city counsel in January 1998, 11 mgd of treated water would be sent through a 34-mile pipeline to the Geysers steamfield. Provided the project meets environ~ mental requirements, completion is expected by the year 2002. One idenlified potential problem with the Lake County and Santa Rosa effluent-to-electricity projects is the seismic activity caused by injecting treated water into steamfields. Lake County initiated a seismic monitoring program and convened an advisory committee to review the collected data. According to the committee, the results indicated thaI several months alter the project began, operating seismic activity had not increased.