About: http://webisa.webdatacommons.org/277696131

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Periodically, filter beds of this nature are backwashed to loosen up the sand, Anthrafilt or other granular material and also to flush away the solids entrapped therein.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com