Drink water from the Bay.John Branchard chronicles the drinking water in the Bay.John Branchard's Chronicles, water supply uncertainty, memory of a near-catastrophic drought, the water authority of Marin County is working on an idea as old as Arion-Beat the sea.The Marin City Water Authority, following calls from environmental activists, is working on a proposal to downplay the waters of San Pablo Bay with 5 million to 10 million gallons of drinking water per day, enough to provide up to 30,000 homes per year.It will be the first desalination plant in the Gulf region and the only desalination plant in the state to enter the closed Bay and estuary.The idea reflects an ugly reality in California.Experts say that even if there is no drought, there will soon be not enough water for the number of people pouring into the state.At the same time, the cost of dams and pipelines-Accompanying environmental mitigation-Sky shooting makes it more and more difficult to dig into existing waterways.The pressure is so great that water officials are eager to find alternatives.Many California water brokers are considering options for desalination.The problem is desalination.-Although not as fancy as when Greek philosophers thought about concentrating Ocean Steam-Still very expensive.Research shows that it may take up to $100 million to build a factory in Marin and lay pipes.Critics say even if it can be built at a lower price, it will cost more electricity than anyone can afford."I was told about two.Three of the costs of operating desalination plants are electricity costs, "said Dick Hill, one of two skeptics on five projects.Member of the MMWD board."It uses more power than the traditional way of treating water."But Jared Huffman, chairman of the board, insists that desalination is a viable alternative to pipelines and dams, especially when people consider the pace of technological progress and cost reductions."Desal provides us with a very reliable, highQuality water sources allow us to stay away from our troubled rivers and streams, "Hoffman said."I think it's also economically feasible."In fact, the same cost as in 1991, the cost of building a factory now will be roughly the same as the cost of Marin's last consideration of desalination in 1991.Although construction costs in the Bay Area rose 30% during that time.Hoffman and other supporters foresee a collaboration with the Marin central sanitation area, allowing them to combine saline extract with treated wastewater, creating a more natural by-product for the disposal of the bay.So far, only two cities in the United States have been fully built and operated.Mature desalination plant-Key West, Fla.In early 1980, Santa Barbara, 10 years later.These businesses were quickly put on hold when cheap alternatives emerged.There are only a few small, mostly private desalination plants in California.Desalination is indeed a prominent source of water, only in places like the Arabian Peninsula, where there are virtually no alternatives.But the trend is shifting.A surge in population in the state--The current population of 35 million is 10 million more than in 1977, and it is expected to exceed 50 million by 2020 ---It has attracted the second attention of water officials."We 've seen the long-awaited demand for desalination gradually shift to demand for desalination," James Berkot, an international desalination expert, wrote in a recent State of North America report."This shift will slowly accelerate."Water brokers from the coast to the coast are already rushing salty waves with a siphon.Tampa Bay is expected to power the largest municipal desal plant on Saudi Arabia's side in early 2003.But the plant is only half the size of two planned plants in Southern California ---There, water officials face the possibility of losing the current Colorado River.The city of Carlsbad in San Diego County and Huntington Beach in Orange County propose the establishment of a desal plant capable of producing 50 million gallons of fresh water per day, enough to serve 110,000 families a year.Factories that produce at least 25 million gallons a day-Almost as big as Tampa--In works near three other cities in Southern California.Santa Barbara is preparing to clean up the factory it has stored in the first sign of drought.Last month, Morro Bay launched a much smaller plant that was sealed seven years ago.The $5.4 million of the plant, which produces 430,000 gallons a day, is the only municipal desalination plant in California."I think desal will be the main source of supply in Southern California in the future," said Ken Weinberg, director of water resources at the San Diego County Water Authority.There are 5 million people."Our population is growing in California, but our water supply is not."The plant that Marin County is considering suggests that even in the relatively humid northern California, concerns about the future of the state are driving water policy, which has basically obtained all the water from natural resources.Although Marin is blessed by the virtual rainManufacturing Machines--Mount tamapawa--Instead of growing so fast in other counties, it felt the pressure.The average annual rainfall in Marin is more than double that in San Francisco, where rain enters seven reservoirs.However, as found in the region's drought in the 1970 s and early 1990 s, in the years of drought, the lakinas River, the main tributary of simalin, does not have enough resources to maintain the number of people as well as local salmon and trout.As a result, regional officials reached an agreement with the Sonoma County Water Authority to allow MMWD 184,510 customers in southern and central Marin to get 25% of the water from the Russian River.The water is delivered for a fee through a pipeline owned by the North Malin Water District, which serves Novato.This is where the problem begins.As the population of Marin County grows, the use of water is expected to exceed the pipeline capacity to supply both areas.In fact, MMWD has to pump water during the winter months, forcing the area to guess how much water is needed in the summer.In wet years, it is often wasted with excess water.The expected solution for MMWD is to build a pipeline that costs $20 million in-The basis needed by voters in 1992.However, this alternative has aroused strong opposition from environmental groups.The main argument against this pipeline is that Russian rivers and their fisheries are degraded by gravel mining and other development plans and cannot be relied upon, especially if restrictions of use and expensive mitigation measures are ordered."As a Russian river contractor, there is a lot of financial and environmental baggage, and desal is everything that the source does not have," Hoffman said ."."It's very reliable, and the potential environmental footprint is much smaller, which makes us ourselvessufficient.Bob Cassell, water quality manager at Marin Water, said it would cost an estimated $34 to build a plant that produces 5 million gallons a day.5 million.A 10 million-The gallon factory is about $60.5 million, he said.Depending on the size of the plant, it will cost $20 million to $35 million to upgrade the distribution system.The castle believes that the main environmental problem of Marin al, if a waste water treatment plant is used-salt water treatment will not be a problem for Marin.But the toughest obstacle is reverse osmosis.-The process of forcing water through a halfMembrane blocking salt molecules-It's still expensive.It takes a lot of power to get water through the membrane, which is why most desalination projects are built with power plants.The Carlsbad plant, for example, will be built by Poseidon Resources.In collaboration with Capello, the oak power station is located at the same location.The Desal plant will have off-the-shelf power supply and will use the existing sea water inlet and cooling water outlet of the power plant."Partnerships like this are critical to the success of seawater desalination," said Mr. Winberg .".One advantage of Marin is that the bay water is warmer and more salty than the ocean, thus reducing the energy of desalination.-However, the option to pair with the power plant does not exist.Desalination has been a concept since the 4 th century.C.When he suggested concentrating seawater steamThe first crude oil plant was installed in Key West, Florida, on 1862.Military personnel supporting Fort Zachary TaylorIn 1977, California began serious discussions about collecting seawater, the worst drought in California's history.Another six-A year of drought that ended in 1993 prompted several counties, including Marin, to start studying desalination.Ultimately, however, because of the high cost, most communities avoid it, often many times higher than traditional sources such as underground reservoirs, lakes, rivers, streams and reservoirs.Marin waters are in the early stages of planning, but an engineering study suggests there is reason for optimism.Found a 10 million-A gallon plant per day will meet all the imaginable future needs of the region, if it is combined with the current distribution of the Russian River.A 5 million-gallon-a-The day Factory is combined with the river water in the pipeline, except for 1977-According to the engineer, it's like a condition.Even though California's electricity is not cheap now, it is not enough.-Its cost has doubled since 1991-He did not hesitate to call the desal plant a future investment.For those who care about the taste, he said 95 of the 100 people who built a pilot desalination plant in 1990 liked saltWater from the bay is free.The evidence in support of desal was convincing enough that earlier this month, the water district commission agreed to hire a consultant to conduct a public opinion poll on whether a plant should be built.This was the first action in the process, eventually putting the county at the forefront of the national movement."If we don't take action, it will be irresistible to push the pipeline forward," Hoffman said ."."Desal is the only option."The cost of seawater desalination: between 1980 and 2000, the cost of the anti-permeable membrane fell by 86%.At the same time, productivity increased by 94%.Environmental issues: the salty extract, known as brine, is a concern for environmental activists because such a high salt concentration can disrupt natural processes if dumped undiluted into the ocean or the Bay.Desalination plants also produce a small amount of solid waste or sludge that must be transported by truck to the landfill.The cost of building the plant: building a 100 million gallon desal plant per day in Marin County, including the construction of new pipelines, up to $10 million, the same cost as in 1991.Factories that produce 5 million gallons a day are estimated to cost $34.To build 5 millionA 10 million-The gallon factory costs $60.5 million.An additional $20 million for 5 mgd plants and $35 million for 10 mgd plants must be used to upgrade the distribution system.In 1991, it will cost $55 million to build a 5 mgd plant and upgrade the distribution system, almost the same as today.This is because the cost of the anti-permeable film has dropped since 1991, similar to the increase in construction costs.Once running, California's high power costs must also be taken into account.Capacity calculated in gallons per day: 5 mgd, 10 mgd, or.Where residents of Marin are taking water now: The Marin City Water Authority operates seven reservoirs that supply 184,500 customers within 147 square miles.The area, through a contract with the Sonoma County Water Authority, covers an additional 8,300 acres.25% of the water comes from Russian rivers each year, accounting for about the total supply.Where they propose to build it: on the land owned by MMWD at the end of Pelican Road on the north side of the San Quentin Peninsula, about a mile west of Richmond/San Rafael Bridge.More information about: www.poseidonhb.Com/media/OC_Proj_Brief_2002_08.