Open covers thoroughly, check inlet and outlet baffles and tees, file cracks or corrosion

https://star-wiki.win/index.php/Reputable_Sewage-disposal_Tank_Emptying:_What_to_Expect_from_Expert_Crews

Open lids thoroughly, check inlet and outlet baffles and tees, document cracks or corrosion, and repair seals to stop groundwater intrusion and exfiltration that can overload the drainfield.