This year, we added the federal government’s environmental liability to our High Risk List—our biennial report highlighting areas particularly susceptible to fraud, waste, abuse, mismanagement, or needing a fundamental transformation.

When federal government activities contaminate the environment, the government’s on the hook for the cleaning bill. In 2016, this bill was estimated to be $447 billion, and the actual costs may be more.

Watch David Trimble, a director in our Natural Resources and Environment team, explain why we added the government’s environmental liability to our latest High Risk List.

• Comments on GAO’s WatchBlog? Contact blog@gao.gov.