<http://webisa.webdatacommons.org/168172570>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<epa.gov> .
<http://webisa.webdatacommons.org/168172570>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/prov/255843316>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/168172570> .
<http://webisa.webdatacommons.org/168172570>	<http://www.w3.org/ns/prov#value>	"Mine production remained relatively steady during this recent increase, suggesting that factors other than production, such as changes in the composition of the ore body and waste rock, have contributed to this upward trend (U.S. EPA, 2013)." .