Why inspect a septic system?
A septic system works out of sight, and problems often develop slowly before they show up as a backup or a soggy yard. Regular inspections catch issues while they're still repairable: a broken baffle, a cracked tank, roots in pipes, a failing pump or alarm in systems that have one, or early signs of drain field stress. Inspections are also standard when buying or selling a home with a septic system, and some counties require them at sale or on a schedule.
Warning signs between inspections
- Slow drains or gurgling sounds throughout the house.
- Sewage backing up into toilets, tubs or floor drains.
- Sewage odors indoors or outside near the tank or drain field.
- Soggy ground, standing water or unusually lush, green grass over the drain field.
- An alarm sounding on a system with a pump.
- High nitrate or bacteria levels in a nearby well.
If you notice these, reduce water use and call for an inspection promptly.
What a thorough inspection covers
1. Records and history: the system's permit and design, its age, previous pumping and repairs, and how many people live in the house. 2. Locating components: tank, distribution box, drain field and any pump chamber. 3. The tank: sludge and scum levels, the condition of the tank walls and lids, inlet and outlet baffles, effluent filter, and signs of leaks or groundwater intrusion. Pumping is usually done as part of a thorough inspection so the tank can be examined. 4. Distribution and drain field: the distribution box, signs of uneven flow, surface wetness, odors and vegetation patterns. Some inspections include probing the soil or a hydraulic load test, where water is added to see how the system responds. 5. Pumps and alarms on systems that have them: float switches, pump operation and alarm function. 6. Camera inspection of lines when there's a concern about blockages, roots or breaks.
Real estate inspections
If you're buying a home on septic, ask for the system's records and arrange an inspection by a contractor who will open and pump the tank. A visual walk-over alone can miss problems. Find out what your county requires at the time of sale. If problems are found, the report can guide negotiations or repairs before closing.
Reading the report
A useful report includes a diagram or description of where components are located, the condition of each part, sludge and scum measurements, any defects found, and recommendations with urgency. Ask the inspector to explain anything you don't understand, and keep the report with your house records.
Questions to ask
- Will you pump the tank so you can inspect it fully?
- Will you inspect the drain field, and how?
- Do you check the distribution box, baffles and effluent filter?
- Does my county require inspections at sale or on a schedule?
- What do you recommend, and how soon?
How often to inspect
EPA guidance is that household septic systems should be inspected regularly, typically at least every three years by a service professional, with pumping as needed. Systems with pumps, alarms or advanced treatment units need more frequent attention. Your county may have its own requirements.
Risers and access
If the tank lids are buried, an inspection includes digging to find them. Installing risers during the inspection makes every future visit faster and cheaper.