Summary: <p>A chemical spill left 300,000 West Virginians without safe tap water. Now, weeks later, officials say they've identified a second chemical. An update on the spill and safeguarding Americans' water supply.</p>
Summary: <p>A chemical spill left 300,000 West Virginians without safe tap water. Now, weeks later, officials say they've identified a second chemical. An update on the spill and safeguarding Americans' water supply.</p>