Committing a little attention to the care of your septic system can help to avoid the cost and embarrassment of a failing system. Assuming that your septic system was properly located, sized, designed and installed according to county codes, you can reasonably expect 30 years of useful life.
Septic tanks can fail. If they do it is often attributable to exposure to methane gas in the secondary tanks, deteriorating concrete caused by corrosion, or faulty mix of the concrete when constructed.
Drainfields can fail for a number of reasons. Drainfields are constructed of porous piping (laterals) laying in a bed of stone atop an absorbent soil bed. Several laterals are connected to a header pipe (think of tines of a fork), which is fed from a discharge pipe connected to your septic tank. When working normally water flows through the laterals, drops through the holes in these laterals, and is absorbed into the soil and cleansed. As these laterals or the surrounding soils start to plug from organic matter pushed from the septic tank, the wastewater has further to go along the lateral before it can drop into the soil. When the laterals and or surrounding soil are fully coated by this bio-mat, water flow from the septic tank rises filtering through the sidewalls until plugged. When the wastewater has nowhere to go it leaches upward and is pushed back into the septic tank and house.
Septic systems can fail due to infrequent cleanings and inspections, poor soil for proper drainage, improper installation of the tank or drainfield, over use, putting too much water in the system, and age.
There is no additive that eliminates the need to regularly have your tank cleaned. Additives may accelerate production of bacteria and subsequently convert much waste to liquid but there is always sludge that builds and left unchecked, it flows into the drainfield and clogs it.
Regular cleanings include an inspection, which can save a drainfield should a baffle fall off the discharge pipe. Without a baffle, scum, grease and oil, floating on the surface of every tank are driven directly into the drainfield, thereby accelerating its demise.
Is your system failing? Does it exhibit these signs?
Laundry consumes many gallons of water. Rinse cycles usually test the capacity of any drainfield. It is often laundry day that exposes the failing drainfield.
Slow flushing toilets and sinks.
Bubbling sounds coming from the toilet and drains.
Sewage backup in lower drains within the home, such as a basement or first floor drain, when other drains in the house are being used.
Excessively lush green grass over the drainfield. Fed with nutrient rich water, this grass thrives. Also, there can be a septage smell radiating from the ground, evidence of dogs or other animals digging there.
Effluent surfacing from the ground, or soft spots in the drainfield.
Remember that even a failed drainfield will dissipate water given enough rest. Some homeowners limp along by stretching laundry across several days, balance showers across the day, doing anything to minimize the water flow and extend the life of the failing drainfield.
Once failed, a drainfield takes several years without burden to regenerate. While it can take years to regenerate, expect it to handle 2/3 its original flow.
Often homeowners put in a second drainfield and install a diverter valve enabling the homeowner to switch flows from the septic tanks between fields A and B.
It is generally much less costly to install a new drainfield than it is to totally remove and lay a new drainfield in the same location as the original.