Measure sludge and scum with a sludge judge to verify pumping need

https://wiki-zine.win/index.php/Septic_System_Pumping_and_Setup:_Cost-Effective_Solutions_You_Can_Trust

Step sludge and residue with a sludge judge to confirm pumping requirement, then mix contents gently to suspend solids so the vacuum truck removes both layers, preventing blockages and early refilling.