Bacteria already in the ground could clean drinking water in the Inland Empire. According to Janet Zimmerman at the Press-Enterprise, water districts are developing system whereby water is pulled from well, run past these bacteria, which eat perchlorate and nitrate and VOCs, volatile organic compounds (well, digest them), producing nitrogen gas which can get released to the atmosphere with oxygen. Then they zap out the waste bacteria, chlorinate the mess and bam! Drinking water.
Though biological treatment is more expensive up front, about $4.2 million vs. $3.8 million for ion exchange, it saves money in the long run because it can treat high levels of contaminants and treats multiple chemicals in a single process. Biological treatment is about $238 per acre-foot of water, compared to $254 for ion exchange, according to a 2009 study by the Department of Defense.
Western Muni and West Valley (in Rialto) water districts are getting these projects underway now - with state and federal funds in hand, en route, or applied for to build the plants. The chemical-munching bacteria already do their business on water that's injected back into wells. I'll be interested to see how well these projects work for drinking water: if in the future our water treatment systems could be cheaper and create less waste, this is an idea that might grow like...bacteria that are fed vinegar and sand like these bacteria are. Mmm, sand.