During pumping, maintain constant vacuum, prevent tank wall damage, break up heavy solids with agitation
https://shed-wiki.win/index.php/Partnering_with_a_Grease_Trap_Company:_Daily_Readiness_and_Regulatory_Compliance_for_Food_Services_36395
During pumping, maintain constant vacuum, prevent tank wall damage, break up heavy solids with agitation, and never ever go into the tank; fatal gases need strict confined-space safety protocols.