jane reports from carlsbad california. >> bone dry california sits next to the largest source of water in the world. the pacific ocean. turning saltwater into fresh is expensive, requires a lot of energy and isn't good for nearby fish but california is running out of choices. >> we are standing in the middle of the reverse osmosis plant. >> josica jones is showing off the $1 billion plant built by poseidon and providing 70% of the water to the county. >> behind me is a feed line. >> they are financing the plant and san diego has agreed to buy the water at a fixed price for 30 years. >> water from the desallination plant is double the cost of imported water. >> that means water bills will go up an estimated $6 per month for the customer but the plants price will never change and never run out of water. it will be pushed through fine filters to reduce the sult at 900 pounds per chance of pressure. >> if that were to break, it would shoot the water into the air at 9 miles per hour. >> and they plan to use it as a turbine to reduce costs. >> the carlsbad project has been under development

it's in carlsbad, california but really for san diego county. once opened, it will deliver 50 million gallons of water a day, supplying about 10% of the county's needs but that makes a dent. they take about 100 million gallons of water leaving a power station divert it to the plant and filter it to remove sand, salt and other terse and in the last step do the osmosis under pressure with filters and physically separate the salt and water out through a sieve. for now in california, this big plant and they're looking at possibly 15 other projection over the years because of the big drought situation. >> too bad they can't sell the salt. thank you, nicole mitchell. >> five years after the worst oil spill in u.s. history the debate over the state of the gulf is far from over. cleanup from the deep water horizon disaster is complete. this week saw two conflicts reports assessing the area. >> it was the worst oil spill in u.s. history 3 billion-barrels of oil poll looted the gulf. two reports are released, one from b.p., the company that owned the well

california's water crisis? jane wells has been looking for answers. jane? >> reporter: mandy surf's up here in carlsbad. l that water off california. the problem is it's got salt in it. up next, desallination finally comes to california but it ain't cheap. we'll have that story next. >>> the city in today's powerhouse is home to the first pizzaria in america. this city has over 722 miles of subway tracks and 48 fortune 500 companies are headquartered here. can you name that city? [intercom] drivers to your marks... go! it's chaos out there. but the m-class sees in your blind spot... pulls you back into your lane... even brakes all by itself. it's almost like it couldn't crash... even if it tried. m-class. see your authorized dealer for exceptional offers through mercedes-benz financial services. here at the td ameritrade trader group, they work all the time. sup jj? working hard? working 24/7 on mobile trader, rated #1 trading app in the app store. it lets you trade stocks options, futures... even advanced orders. and it offers more charts than a lot of the other competitors do in desktop. you work so la

our first report comes from student television network correspondent sydney payne at carlsbad high school in california. as part of our series on what's changed, she and her team visited a local san diego elementary school that was the scene of a terrifying shooting in 2010. we're calling the series "the new safe." >> reporter: friday october 8 2010, began as any other day begins at this suburban san diego elementary school. it was lunchtime and the students were heading out on to the playground. at about the same time 41 -year-old brendan o'rourke pulled up to a curb outside the school. he was armed with a .357 magnum revoferler a red gasoline can and a propane tank. >> it was a typical friday. everyone was wearing their spirit ware. it was very relaxed. we heard a gunshot. we heard over the walkie talkie the custodian was yelling that somebody was shooting at the children. >> there was a loud bang and everybody thought it was like a big firework. so everybody is looking up, like up over there because that's where he was. everybody just looks up at everything, and nobody knows what's going on. and the