SR 06:147 - Laserfiche WebLink

storage and is in the process of acquiring more drought-related water supplies than planned for in the late 1990s. As a result, this 2013 date is a conservative estimate of the sustainability of current Zone 7 supplies in relationship to projected demand. Zone 7 has sufficient water and storage to maintain full water deliveries through General Plan build-out of its customers - including PIeasanton. To maintain water supply sustainabiIity, Zone 7 is currently exploring other sources of imported surface water and out-of-basin groundwater storage . s projects. In the short-term Zone 7 can use both local and out-of-basin groundwater storage projects to offset any demand deficits through the use of these groundwater storage assets. The local groundwater basin that Zone 7 manages currently holds approximately 202,000 acre-feet. The groundwater basin is considered full at about 240,000 acre-feet, and Zone 7 estimates that approximately half of this amount is available by well pumping. Zone 7 plans to install a well network capable of producing 75 percent of its maximum day municipal demand. With this capacity, Zone 7 could supply its users with an acceptable volume of water during droughts or emergencies (such as when any major facilities - the State Water Project, the South Bay Aqueduct, etc. - are out of service). Zone 7 has recently installed two new wells capable of producing 6 million gallons per day (mgd) each of water (Mocho Wells No.3 and No.4). With these wells in place, Zone 7 can pump enough water from the groundwater table to meet approximately 60 percent of current demand. It has just approved a contract to begin drilling two new quarry-area wells to increase groundwater pumping closer to the 75 percent current water demand level. As growth continues in its service area, Zone 7 will continue drilling new groundwater wells to increase its pumping capacity to the 75 percent- demand level. Besides the quantity of water supply, PIeasanton residents are concerned about their water quality. Some citizens complain of earthy-musty taste and odor (caused by decomposing algae in surface water sources), water hardness (caused by minerals such as calcium and magnesium in the groundwater basin), and the taste of chlorine in the water. In 2003, Zone 7 Water Agency established a Water Quality Management Program to help define the issues and causes of taste, odor and hardness, and to identify methods to meet anticipated future water quality standards.6 Currently, Zone 7 has two projects that are either under design or are being implemented in the short-term (next five years) to improve water quality (i.e., taste, odor, and hardness). The first is the Mocho WellfieId Demineralization Project (which will reduce the hardness of the local groundwater delivered by Zone 7). The second is the temporary introduction of powdered activated carbon at its Del Valle Water Treatment Plant. Zone 7 currently has water treatment plants at Del Valle and Patterson Pass for processing surface water before its distribution. (See Figure VI-3, above, for the location of these two plants.) For a longer term improvement to , Zone 7 Alameda County Flood Control and Water Conservation Distriet, "Annual Review of the Sustainable Water Supply," May 19, 2004. 6 Zone 7 prepared a biannual Water Quality Management Program Report Card and Status Update, 2003-2004, to sunnnarize data and update the Water Quality Management Program. VI-12