Septic Tank Maintenance and Inspection. A septic system is the most common method of sewage treatment for homes that are not on a public sewer line. A septic system consists of a septic tank, where solids settle and decompose, and a drain field where liquid discharged from the tank is treated by bacteria living in the soil. The septic tank settles out and decomposes solid sewage. The resulting liquid discharge from the tank slowly seeps into the drain field where it receives final treatment from bacteria living in the soil. Properly functioning septic systems treat sewage to prevent ground and surface water pollution. A malfunctioning system is a health hazard to your family and your neighbors, and will harm natural resources.
The solid-liquid separation is usually accomplished in what is called a treatment tank. The treatment tank is a relatively large structure typically made of concrete. The approximate size for a residence is 1000 to 1500 gallons. The solid material and liquid material enter the treatment tank by means of the drain pipe from the house. In addition to separating the liquid material from the solid material, the treatment tank also provides partial treatment of the septic waste through biological action within the tank. The solid-liquid separation is accomplished by the use of baffles within the tank. The inlet pipe is usually located at one end of the treatment tank and the outlet pipe at the other end. The normal liquid level in the treatment tank is at the level of the outlet pipe. The solid material that is heavier than water sinks to the bottom of the tank where biological breakdown occurs. Any solid matter that floats is prevented from going out the outlet pipe by means of an outlet baffle which extends just below the surface of the water.
While the treatment tank provides some treatment of the septic waste, it does not get rid of harmful bacteria and viruses, so further treatment of the waste is necessary. If soil conditions are adequate, this further treatment of the septic waste can be accomplished in the absorption area by biological action which takes place in the presence of air. Such microorganisms are known as aerobic.
Some of the common signs your home’s septic system might be malfunctioning? A clogged or overflowing septic tank might result in soggy, wet soil near the site. Also keep an eye out for pooling “gray water” that might be visible in the yard or grass above or around the tank area or leach field. Homeowners often report a strong waste odor outside. You might also find clues inside, such as clogging or backed up drains, which might be the result of a clogged sewage line, a full septic tank, or similar issue.
You pump out your septic tank to get rid of the solid sludge that accumulates at the bottom of the tank and the grease that accumulates as scum floating near the top. Both sludge and grease can foul the leaching field. How often to pump out depends on your tank size, family size, and how much of your wastewater is solid waste. For example: suppose your tank is 1,500 gallons, you’ve got four people in the family, and your solid waste is the average amount. Then you should pump your tank every 4 years. The volume of solids in the wastewater varies with such things as garbage disposals, dirty clothes, where you live. A family with a garbage disposal (compared with one that scrapes the dishes into a trash can) dumps up to 50 % more solid wastes down the drain, and, therefore, needs to pump the septic tank twice as often. Additives don’t do any good-or, at least, no controlled scientific study has shown them to be effective. So, save your money.
A non-invasive inspection of a septic system is often a good starting point for helping to determine the condition of an existing septic system. The following procedure is used by some inspection companies. Not all inspection companies will follow this same procedure, and since there are many variations in septic system design and function, each inspection is likely to be unique in its own way. Non-invasive inspections leave the soil virtually undisturbed and do not alter the system in any appreciable way. Any available, readily accessible access caps are removed and the liquid level inside is observed. The water inside the home is run for a minimum of thirty minutes. During this time the liquid levels in the access pipes (if any) are observed and the absorption area is examined for seepage or lush growth. The technician relies on visual signs for detecting any defects in the system. Since the soil is undisturbed this kind of inspection can be performed without damaging the lawn or risking the damage caused by digging up parts of the system.