it at full force. it's being very diluted because it's going through the water system. no real major health problems, but of course it's worrisome that people might have been exposed to this. >> elizabeth cohen, our senior medical correspondent, thank you. >> this is a major crisis in west virginia. it all began when a giant tank at freedom industries leaked a chemical used in coal processing. it spilled into the elk river contaminating a water treatment plant in charleston. gary southern says his company is working with authorities to handle the situation. >> we are very, very sorry for the disruptions in everybody's daily life this has caused. we worked through the night last night to remove all the material from our site. the material is no longer here. >> drilled down on this story, the potential health risks. with me is the mayor of charleston, danny jones, whose