All wastewater from your home drains to a septic tank. Weighty wastes sink and form a layer of sludge, while fats and oils float to the top and form a layer of scum. Bacteria in the septic tank break down these solids so liquid waste can flow out of the tank.
A septic tank contains household plumbing wastewater that runs through a sewer line. When a toilet is flushed, showers are used, or dishes are washed, wastewater flows into the sewer line. The line slopes downward toward the septic tank, and each drain in your home connects to a fitting. All these connections make up the septic system. Visit Website to learn more.
Wastewater enters the septic tank, and the bacterial decomposition process begins. Heavy solids, such as bones and twigs, sink to the bottom of the tank where they are broken down by bacteria into sludge. Lighter masses, such as grease and oils, float to the top of the tank and form a scum layer. Bacteria break down the scum and sludge, leaving behind partially treated wastewater or effluent that seeps through to the drain field.
Once inside the tank, the wastewater travels through a distribution box and into perforated pipes set in trenches of gravel in the absorption field. These pipes allow the water to slowly seep through soil layers, where natural filtering processes remove disease-causing organisms and organic matter from the liquid waste. The purified wastewater then seeps into groundwater or evaporates from the soil.
The tank is usually made of concrete or lined with pre-fabricated plastic rings. A baffle divides the tank into two chambers, so that scum and solids remain in the first chamber and the liquid wastewater flows out through the second. This reduces the need to pump the septic tank as frequently.
In some cases, a septic tank has three or more chambers. This can be useful if your household produces a lot of solid waste or if you don’t have the space for a large absorption field.
The septic tank is vented, or allowed to release gases, to prevent a build-up of pressure that could stop the flow of wastewater from your house or push it back into the pipes. The most common gas produced is hydrogen sulfide, which smells like rotten eggs. The ventilation system consists of a pipe through the lid of the tank, which can be fitted with a charcoal filter to reduce odors.
The sewage from your bathroom and laundry rooms passes through your plumbing into the septic tank, where solids sink to the bottom and liquid waste floats to the top. Heavy solids are absorbed into the sludge layer at the bottom of the tank, while bacteria break down light solids and liquid waste. When the liquid waste is ready to be dispersed, it leaves the septic tank through a pipe into an absorption area known as a drain field or leach field.
When a septic system is working correctly, the buried perforated pipes in the drain field allow wastewater to seep into the soil at a controlled rate, resulting in natural purification of the liquid waste. The bacterial and microbial action in the soil filter the effluent further, eliminating disease-causing germs and organic matter. The filtered water eventually moves to groundwater or evaporates from the surface of the soil.
Over time, a well-functioning drain field can treat up to 40,000 gallons of sewage a day. But problems can arise that prevent the drain field from functioning properly, causing sewage to back up into the home.
Many things can clog the drain field pipes, including tree roots and other plants that are growing around or near the septic tank and pipes. Foreign objects that are flushed down the toilet or sink, such as paper towels, feminine hygiene products and cleaning products can also clog the pipes. Too much rain or snow can flood the drain field, preventing it from accepting sewage waste.
Often, if there are problems with a septic tank or drain field, it means that proper maintenance is not being performed on the system. This includes regularly scheduling an inspection and having the septic tank pumped. If you cover the drain field with a driveway, parking lot or storage building, the weight of these structures will crush the perforated pipes underneath and interfere with the natural absorption process.
In some cases, a septic system may be designed with multiple drain fields to accommodate different capacities of the household. If one of these areas is overloaded, the others will “rest” while the excess sewage goes to another area. During this period, the nematode community in the resting drain fields continues feeding on accumulated fats and sludge, improving the drainage capacity of the resting drain field to approach the percolation rate of the original clean drainfield.
Sewer gases, including hydrogen sulfide, ammonia and methane, can be unpleasant and unhealthy to breathe in high concentrations. These chemicals are produced by bacteria breaking down waste, and can lead to eye irritation, breathing problems, coughing, loss of consciousness or even death if inhaled for extended periods of time. Septic tank odors are the result of these gases and can often be smelled inside the home, or in areas near the septic system like the leach field. If you smell a foul odor in your home or near your septic tank or leach field, this is usually a sign of an issue that needs to be addressed.
Bad septic tank odors can be caused by many different things, but the most common cause is a clogged drain line. If your drains are clogged with hair, grease or solid waste, they can no longer efficiently vent away the bad septic tank odors. It’s important to clean your drain lines regularly to prevent them from getting clogged.
Another common source of septic tank odors is when the plumbing traps dry up. These are u-shaped bends in the plumbing, with one end connected to the drainage pipe and the other to the septic tank vent pipe. These traps hold a small amount of water and help keep septic gasses from traveling back up into the house. If these traps dry out, they can allow the odors to travel all the way up the plumbing.
If your home is in a low-lying area or surrounded by lots of trees, there may not be enough wind to disperse the septic tank odors away from the house. This is an issue that can be easily fixed by having a plumber extend the plumbing vent pipe to increase airflow.
It’s also possible that the septic tank vent is clogged. The vent stack sends all of the septic tank gases to the outside of the house, so they need to be free of obstructions. If you suspect that your septic tank vent is clogged, contact a wastewater technician or plumber right away. If you don’t address the problem soon, it could lead to a dangerous buildup of toxic gases in your home.
A septic system requires regular maintenance to function properly. You should get your septic tank pumped every 3 to 5 years. This removes the sludge that accumulates within the tank. If the sludge doesn’t get pumped out, it can build up and cause your drain field to fail. This isn’t something you want to happen!
All plumbing in a home with a septic tank converges at the septic tank. The septic tank is a large, water-tight container made of concrete, fiberglass or polyethylene. It’s buried underground and has compartments for solid waste to settle to the bottom in a sludge form and oil and grease to float to the top as scum. Liquid wastewater from the home flows through a tee outlet into the drain field area. This waste is treated by bacteria in the soil before reaching groundwater.
Biological additives sold by septic tank companies claim to balance the bacterial levels in your septic system. This may help the septic tank to operate normally, but these products do not replace the need for regular pumping and periodic septic cleanings.
If a septic tank is not functioning normally, sewage can back up into the toilets in your home and overflow into the absorption field. This can contaminate nearby drinking water wells and waterways with disease-causing organisms. It also creates excess nutrients that can lead to toxic algal blooms in local waterbodies.
The best way to avoid these problems is to have your septic system regularly inspected and pumped. Also, don’t build structures or plant anything over the septic tank, drain field or distribution box. Also, keep kids and pets away from the septic system, as this can damage it or cause a septic tank leak.
It’s important to only flush septic-safe items down the drain and toilet. This includes paper, biodegradable products and septic-safe toilet tissue. Items that don’t break down, such as wipes and cat litter, can cause blockages in septic tanks and drain fields and should be disposed of with the trash. Water detection technology can be helpful to alert you of septic tank problems before they become costly and messy.