What is a Septic Tank?
A septic tank holds wastewater for some time to allow solid waste to settle down and decompose. The heavier solids (sludge) sink to the bottom, and lighter materials like oils and grease float to the top.
Septic Tank compartments and an outlet baffle wall prevent sludge and scum from leaving the tank and traveling into the drain field area. It’s important to pump the septic tank on schedule, as overuse can cause failure of the soil absorption field. Check out Septic Tank Services for more information.
All water running into your home from sinks, toilets, and appliances goes through one main drainage pipe to the septic tank underground. The septic tank holds the wastewater long enough so that the solid waste in the water (sludge) can be separated from the liquids, oil, and other floating materials. This is done by using natural bacteria to break down the solids in the tank. Then, the liquid wastewater is pumped out of the septic tank into the drain field or absorption system.
The septic tank’s outlet is a PVC “T”-shaped fitting that extends above the bottom of the inlet tee opening. When the tank is full, it is normal, not too low or too high. The septic tank must be emptied regularly as part of routine maintenance.
When the tank is pumped, the liquid effluent leaves the septic tank through the inlet tee opening and enters the distribution box or absorption area, where it’s dispersed into the soil. The water must be treated as much as possible to reduce the amount of sewage seepage into groundwater and surface water. The affluent also needs to be treated to reduce pathogens that can cause disease and infection in people and animals.
If your septic system isn’t pumped often enough, the sludge layer in the tank can build up, and the septic tank may overflow. This can lead to problems, including clogged drains, backups in toilets and showers, or septic tank leaks.
Planting grass and other shallow-rooted plants around the septic tank and drain field is a good way to keep your septic tank and pipes in good condition. Avoid planting trees or shrubs that will grow into the septic tank, lines, and pipes. Keep kids and pets away from the septic tank, pipes, and drain field.
If your yard looks a little greener than usual, you might have a problem with the septic system. That’s because the grass is getting fertilizer from the sewage. If you need to check if your septic system is working correctly, get it inspected by a professional.
The septic tank is a concrete or fiberglass underground chamber through which domestic wastewater (sewage) flows for basic sewage treatment. It holds wastewater for at least 36 hours under anaerobic conditions and performs some settling and organic matter reduction. It is a simple, onsite wastewater treatment system that can be used in rural areas. The liquid portion of the sewage, called effluent, is disposed of in a septic drain field where natural filtering occurs in soil.
Sediment is the fine particulate waste left in the septic tank after sludge and scum have separated. The sediment is not dissolved in the wastewater and may contain pathogens. Biological treatment can occur in the drain field, but it requires much more bacterial action that can take place in the septic tank.
If the septic tank is not pumped in a timely manner, this sludge layer can clog the inlet and outlet tee openings. This can prevent wastewater from entering the septic tank and causing a septic tank backup.
A septic tank that overflows or leaks is a serious health and safety problem. The sewage in the tank contains disease-causing bacteria and other contaminants that can enter soil and surface water. It is also a fire hazard and can cause injuries to household members if they come into contact with it.
Overflows and leaks can be caused by a number of factors, including:
One way to keep your septic tank functioning properly is to prevent excessive water usage. This means not putting too many people through the bathroom at once, using low-flow toilets and showerheads, washing clothes in batches rather than back-to-back, and avoiding putting anything down drains that aren’t supposed to go there, such as fats, oils, and greases.
Another important factor is to make sure the tank is pumped every 3 to 5 years. If you last had your septic tank pumped a long time ago, a professional can help. They can also install an automatic septic tank monitor to alert you when it’s time for pumping.
Septic tank systems must be able to break down and treat the inorganic waste that enters them. This process relies on a host of microscopic bacteria to perform its job. Anything that interferes with or disrupts these microorganisms impacts septic tank performance and increases the rate at which inorganic material builds up inside the septic system.
The heavier solids settle to the bottom of the septic tank and form sludge, while the lighter fats and oils float to the top and form a layer of scum. The sludge and scum layers take up a certain percentage of the liquid volume in the septic tank. The liquid between the sludge and scum is called effluent, and it exits the septic tank through the outlet pipe and flows into the drainfield area, where it will be absorbed into the soil.
In order to prevent the sludge from building up to excessive levels in the tank, the septic tank needs to be pumped on a regular basis. A homeowner can get a good idea of when his or her septic tank should be pumped by observing the level of sludge in the septic tank. It should never be allowed to build up to the point where the sludge rises above the inlet tee opening.
If the sludge level is allowed to rise above this level, the septic tank will not be able to release the clarified wastewater that is effluent into the drainfield area. In addition, when the sludge level gets too high in the tank, it can start to flow out of the tank and back up into the household plumbing fixtures.
Keeping the sludge level in a septic tank at or below this 30% threshold greatly extends the life of a septic system. This can be accomplished by regularly having the septic tank pumped and by not flushing anything other than the three Ps (pee, paper, and poo) down the toilet.
Another way to keep sludge levels low in a septic tank is to use the new, cutting-edge technology that uses methane, the gas produced by the breakdown of sewage, as a source of power in home generators. Using the power of methane is an environmentally friendly alternative to generating electricity with coal or oil.
Septic tank systems are designed to remove disease-causing organisms, organic matter, and most nutrients (except nitrogen and some salts) from wastewater. The bacteria and other microorganisms in the septic tank do this anaerobic digestion for a minimum of 36 hours. Once the solids are dissolved, the liquid wastewater is pumped into the drain field. The soil there is a natural filter, purifying the water as it seeps through and absorbs into the groundwater.
The septic system pipes are made from durable cast iron, plastic, or PVC. They have a diameter of 4 to 6 inches and are buried in the ground. They connect to a distribution box that feeds into the perforated pipe in the drain field. The distribution box has baffles or sanitary tees to ensure floating scum is prevented from plugging the inlet and outlet pipes. The inlet and outlet pipes also have inspection openings to check for clogs.
When the drain field becomes overloaded, it cannot handle the wastewater flow. This overload can be caused by many things. For example, if you have a new septic tank and have yet to have it tested, or your septic system needs to be properly sized for your home’s population, you might experience overloading. Overloading can also happen when more wastewater is sent to the septic tank than normal, such as when you do multiple loads of laundry on the same day or when everyone takes a shower at once.
If you’re experiencing sewage backups in your home, contact your plumber immediately. This is a sign that the drain field or septic tank has failed or is near failure. A failing or clogged septic system isn’t just hazardous to humans and pets but can contaminate nearby drinking water wells. A wet, soggy area in or around the septic tank or drain field with bright green, spongy grass indicates that the drain field has become saturated with water and may need to be replaced. This can be expensive but is the only way to protect your home from sewage contamination.