. >> >> desal nation removes salt and minerals from brackish water. it is often very energy jump tensive. here they've built a desal nation plant that works on solar energy. >> we can use the sun to reduce the amount of fuel or electricity. that's very, very important from an overall solution. >> the most prominent feature is this 377-foot long array of mirrors. >> we're using this large mirror to capture the heat. the sun light is right field here. >> mineral oil travels do you know central tube and heated by the sun to 248 degrees. the heat is then piped into evaporators and steam generated. fresh water is condensed from the steam and salt and other minerals removed in the process. >> what percentage of the water is purified? >> we can go to 93% water recovery. >> is 93% a typical amount of recovery? >> no, it's very high. that's what makes this process different from traditional sea water desalination which operates at 50% recovery. >> wow. >> this recovered water is safe enough to drink. >> i hope it's not that i to have try. >> no, this is the sa

santa clara will consider desal nation to help find a water source during the terrible drought we're in. today the county board of supervisors approved a proposal to explore water-generating technologies. desal nation is effective, but it's extremely expensive and can cause environmental problems and there are at least 15 plant across the state with three already in operation. >>> a lot of folks in the bay area are trying to make a difference in the drought by saving their shower water. some are calling it the bucket challenge. abc 7 news reporter joins us from oakland to explain. it's a new one wayne. >> good evening, cheryl. that challenge may be taken on by every single person behind me. take a look. that is oak lasched behind us on east bay mud has asked consumers to cut water consumption to 2013 levels and each then customers will be paying more no matter what due to a drought surcharge. you might want to take a close look at that water bill and you might even want to buy a bucket. >> open the mail hold your breath. in that regard every californian has much in common with pamela

. >> he estimates a desal nation plant could provide water for one in ten people in the county.lant could generate enough water for roughly 180,000 people. >> it is the quintessential answer to water water everywhere. >> it also raises questions. remember, there is california. the plants use huge amounts of electricity. it has to come from somewhere and that increases carbon dioxide which in turn increases global warming and there is fear of impact what this may have on sea life in the area. >> we have to pay a price somewhere. >> speaking of price, they figure it will knock off the average bill by five bucks. >>> damage control after being culled out the worst airport in the country for security breaches. >> but airport officials are blaming its neighbors. one of the 37 breaches at sfo in the last decade, six were boaters and wind surfers passing the 200-yard buffer zone around the runways in the san francisco bay. other breaches were along fence lines but an air force suppose -- airport spokesperson says -- [ inaudible ] >> we have a homeless shelter near the perimeter. we've

right behind me is the largest desal nation plant ever constructed in the western hem fear. we're starting with big farma with an f. california farmers feed the world. there is a huge fight between them and residents because city dwellers have to cut back their water, farmers don't. people are going nuts over almonds. it takes one gallon of water to make one almond. what do the farmers say, especially sips most of those nuts are exported. >> if city residents have to cut 25%, why don't you have to cut 25%. >> unfortunately, we're in the federal irrigation district. i know we've taken criticism in the last couple of weeks that the farmers aren't doing their fair share. i will tell you two years ago we got 40% of our water allocation. -- three years ago. two years ago we got 20%. last year we got zero. >> reporter: could some of your groundwater be pumped to go to cities? in other words, take it away from these trees and send it to people who need to drink water? >> well ultimately people will always have the first call on water and in an extreme situation i'm sure that up and