Be careful with your septic tank. Ask me how I know.
Things to avoid:
- Putting anything solid in your toilets that hasn't already been digested. This stuff takes too long to decompose -- even if it's food waste -- and builds up in the sludge layer at the bottom of the tank. Eventually, the sludge layer builds up to the point where it starts going out with the effluent, which will plug up the holes in the drainfield, causing system failure and necessitating the digging of a new drainfield (upwards of $10K).
- Parking -- or even driving -- your car over the drainfield. This can crush the drain lines, causing beaucoup problems.
- Digging near the sides of an older tank. Here's my personal story about this one. While having some construction done, to build a roof over my patio, the contractors had to excavate down the side of my tank, which is over 20 years old. It turns out that the interior had eroded, and when the backpressure provided by the soil was removed, the pressure caused by the weight of a thousand gallons of wastewater in the tank blew out the side. Thus, I got a new septic tank at great expense, when I could have just let it be and it would have taken 5 to 10 more years to fail on its own.
- Driving a backhoe over the tank. This will collapse the tank and force removal of the backhoe by winch.
- Not having the tank pumped regularly. Your county health department can give you the recommendation on how often to do so, based on the size of the tank and the number of people in the dwelling. The results of doing this are identical to those of the first bullet.
Most people with septic systems tend to forget they even exist. This is a bad long-term strategy, leading to expensive repairs down the line. A septic system (technically called an onsite wastewater treatment system) is an actual, working appliance which needs regular maintenance in order to function properly and not surprise you when you least expect -- or can afford -- it.