Walk around the entire site to note general conditions and check for obvious signs of failure such as surface breakout or ponding. Look for signs of sewage, stains on the ground or saturated, spongy soils. The presence of sewage odors must be determined when first arriving at the site.
Check pumping records for frequency .of system pumping and verify that the system has not been pumped within two weeks prior to inspection.
Interview occupants concerning back-up or break-out or high ground water. Sewage backup into the house can be caused by:
- clogged pipes
- surcharged septic tank
- failed leaching area
It is extremely important that the inspector determine the cause of the backup or breakout. For example, if the problem is due solely to broken or obstructed pipes, this would be considered, a Conditional Pass situation; however, if the cause of the backup or breakout can be attributed to a general clogging of the leaching system by solids, then this could be grounds for failing the system.
Locate and inspect all pipes exiting the building.
Expose and remove manhole covers. If septic covers are more than a foot deep, recommend that extensions be provided to within six (6) inches of finished grade.
Determine material of construction. If the tank is a metal tank this is grounds for a conditional pass providing that no other conditions exist that would trigger a system failure. Unless the owner or operator has provided the system inspector with a copy of a Certificate of Compliance indicating that the tank was installed within the 20 year period prior to the date of inspection.
Check inlet and outlet tees or baffles for damage. Recommend repair necessary based on the requirements of 310 CMR 15.227.
Check liquid levels for evidence of leakage. If tank is discharging when there is no flow from facility there may be infiltration to the tank which would indicate that the tank may be in high ground water and is not watertight. If the liquid level is below the outlet invert then the tank is probably leaking to surrounding soils. Leaking tanks must be pumped in order to inspect them further. If further inspection shows that the tank is cracked, structurally unsound, is leaking or if ground water is infiltrating the system through a crack or seam, this condition should warrant a conditional pass which would require replacement or sealing of the tank if no other failure criteria are triggered. If the liquid level is above the outlet pipe and there is no outflow, then the outlet pipe may be clogged, or the distribution box may be surcharged. The inspector should try and determine the cause. If a surcharge in the tank is due to a broken or cracked pipe or other easily correctable circumstance, the system should merit a conditional pass if no other failure criteria are triggered.
Ensure sludge depth and thickness and record on the inspection form. Recommend pumping as part of the inspection if indicated by being within two inches of the outlet tee.
Check for evidence of backup (i.e. liquid level significantly higher than invert of outlet pipe) Outlet pipe will need to be examined as it enters distribution box to determine cause of backup. If backup is due to broken or obstructed pipe and no other failure criteria are triggered, the system may conditionally pass inspection.
Expose and remove cover.
Determine if d-box is level and if flow is equal.
Check if there is evidence of solids carryover.
Check if static water level is at or higher than invert of outlet pipe. If the liquid level is above the outlet and there is no outflow, either the outlet pipes are clogged or the leaching area is surcharged and in failure. The inspector must determine the cause. The system may qualify for a conditional pass if the high liquid level is due to broken or obstructed pipes, broken distribution box or if the distribution box is uneven or settled.
It should be noted that if the hydraulic backup is due to a soil absorption system which is clogged, the system CAN NOT be made to pass by application to the soil absorption system of physical, chemical or biological agents or treatments. Such failures can generally only be corrected by upgrading or replacing the system. The Local Approving Authority should be consulted before any effort is made to repair or upgrade a failed soil absorption system.
Check the pump function if there is a dosing chamber instead of a distribution box. Similarly, if the system includes a siphon, its condition and functionality should be determined. If the pump is not functioning properly, the system may receive a conditional pass provided that the pump is repaired or replaced. If the siphon is not functioning and cleaning the siphon cannot correct the problem, the siphon should be replaced with a pump system (unless it is part of a recirculating sand filter system or other approved alternative technology). In either case, the entire system does NOT need to be upgraded unless other conditions exist which would warrant a complete upgrade.
Soil Absorption System:
It is extremely important that the inspector locate the leaching system. However, excavation of the soil absorption system, once it is located, is typically NOT required. It may be appropriate to expose a portion of the soil absorption system (especially if the leaching system is a pit) to determine its condition if other indications of failure, such as evidence of breakout, ponding; sewage backup, condition of the distribution box, etc., suggest that a failure of the soil absorption system may have occurred. If the system is a leaching pit, it will generally make sense to open the pit and pump the liquid out of the pit to determine if ground water infiltrates back into the pit.
Approximate layout should be determined by examining the topography and noting drain arrangement from access at distribution box. Location of the leaching system can often be accomplished by running a snake down the line(s) coming from the distribution box.
Determine condition of soil (e.g. clogged, hydrogen sulfide crust, etc.).
Determine level of ponding within disposal area (visual inspection).
Determine if leaching system is below the high ground water elevation.
It should be noted that a soil absorption system that fails because it is clogged, CAN NOT be made to pass by application to the soil absorption system of physical, chemical or biological agents or treatments. Generally, these kinds of failures can only be corrected by upgrading or replacing the system. The Local Approving Authority should be consulted before any effort is made to repair or upgrade a failed soil absorption system.