During pumping, maintain steady vacuum, prevent tank wall damage, separate heavy solids with agitation
https://zulu-wiki.win/index.php/Septic_System_Pumping_and_Setup:_Cost-efficient_Solutions_You_Can_Trust
During pumping, maintain constant vacuum, prevent tank wall damage, break up heavy solids with agitation, and never enter the tank; fatal gases require strict confined-space security procedures.