subject: Maintaining Your Septic System [print this page] How Septic Systems Work How Septic Systems Work
Let's cover the basics of how a septic system operates before we jump into the maintenance tips. The average person goes through 100 gallons of water per day. The septic tank and absorption field are the 2 main components of your septic system. As you operate your plumbing fixtures throughout your home, the solids and liquids from the toilet, gray water from your sinks, dishwasher, tub, washer, and water softener etc run down your sewer line and empty into your septic tank. The solids sink to the bottom while the liquids drain into the absorption field through the laterals. The anaerobic bacteria found in the the solids from human waste breaks down the solids in the tank. Aerobic bacteria found in the laterals help break down the liquids as they pass through the absorption field. If the tank is kept at equilibrium, the bacteria should constantly be breaking down most of the solids allowing the tank to almost be self-sufficient. Septic systems should last a very long time if properly maintained.
The Location of Your Septic System
Here are some general rules for the proper location of your septic system: minimum 15' from the foundation, minimum 10' from surface water, minimum 10' from property lines, and minimum 50' from your well. The absorption field must be a minimum 50' from surface water, minimum 100' from your well, minimum 30' from the foundation. The absorption field consists of a trench that is typically 4'-5' deep by 100' long.
Sizing Your Tank
If you have a 2 bedroom home or smaller, the general rule of thumb is your septic tank should be 1,000 gallons. If you have a 3 bedroom home, your tank should be 1,500 gallons.
What NOT To Put Down the Drain
Using a garbage disposal that's connected up to a septic system is not a good idea. Most people mistakenly assume that when you shove lettuce, noodles, rice, green beans, potatoes...stuff high in starch or stringy greens...the garbage disposal grinds them up into small pieces that the septic system can take on. In reality, no matter how small those foods are ground up, they float and tend to stick together. When that food reaches the septic tank, it will clog the laterals. You also should avoid flushing condoms, sanitary wipes, and diapers. Chemical cleaners that are not labeled 'septic safe' can negatively impact the bacteria levels in your tank leading to sludge and solid buildup. If allowed to continue, this can clog the laterals too. When you choose your toilet paper, it too should be labeled 'septic safe'. If it's not, the paper may take too long to biodegrade and clog the laterals.
Maintaining Your Absorption Field
In the summer, the absorption field evaporates approximately 60% of the water off. This is why it's crucial to never impede the field's surface drainage. Do not pour concrete or asphalt over the absorption field. Do not plant trees or shrubs in the absorption field as their roots can clog the laterals. Do not drive your truck, car, or heavy equipment over the field as this can crush or break the laterals. You also want to limit the volume of water discharging into the tank at any given time. If you have too much water discharging into your septic system too fast, this hydraulic overload can lead to solids and sludge churning, in turn, clogging your laterals also. Space your laundry out and turn your water softener off if you have one. When the water softener is discharging the brine, it dumps a large volume of water into the septic tank which can lead to issues.
Septic Tank Pumping
You want to regularly have your septic tank pumped. Solids and sludge will build up over time. The more you misuse it, the more frequently you'll want to have it pumped. Under normal conditions, you'll want to have your tank pumped every 2-5 years. If you have lots of family members or ignore the above mentioned tips, you'll want to have it pumped more often to try to avoid have your laterals become clogged. If the laterals become clogged, the only solution is to dig up your absorption field and install a new one.
Septic System Inspections
In Iowa and Nebraska, a state licensed septic inspector has to inspect your system. When you hire them, they should perform the following: Check the water level in the septic tank. Then push 100 gallons of water into the system and watch the tank level. An indicator of a clogged or partially clogged later is if the water level rises. They should also judge the sludge thickness, check for cracks in the sidewalls, make sure the inlet and outlet baffles are in good condition, make sure the access port is in tact, and use a 'T'-bar to probe the absorption field. If moisture is found with the 'T'-bar, that indicates the absorption field is partially saturated. They also use the 'T'-bar to determine the size of the tank.
I would like to personally thank Jim Sandvold from S&S Pumping in Blair, Nebraska for taking the time out of his busy day to share with our home inspector chapter his wealth of knowledge on the subject. His company pumps the tanks, performs the inspections, and installs the septic systems in the Blair and Omaha area.
