Funding for this research was provided by:
United States Department of the Interior, Office of Surface Mining Reclamation and Enforcement (OMB No.: 4040–0004)
Article History
Received: 1 March 2018
Accepted: 24 September 2018
First Online: 1 October 2018
Compliance with Ethical Standards
:
: The authors declare that they have no conflict of interest.