Open covers carefully, check inlet and outlet baffles and tees, document cracks or deterioration
https://zoom-wiki.win/index.php/Selecting_a_Specialist_for_Sewage-disposal_Tank_Pumping_and_Cleaning_on_a_Spending_plan
Open lids carefully, check inlet and outlet baffles and tees, file fractures or deterioration, and repair seals to stop groundwater intrusion and exfiltration that can overload the drainfield.