About: http://webisa.webdatacommons.org/270443717

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	For the pond or lake, where algae or scum is a problem, there are valves that have scrubbers that literally scrape the inside of the valve as it is operating, so that the algae cannot build up there, gumming up the works.
http://www.w3.org/ns/prov#wasQuotedFrom	igin.com