Septic tanks are large, buried containers made of concrete or plastic. They hold wastewater while undergoing natural and mechanical treatment. Heavy solids sink to the bottom and form sludge, while oils and fats float to the top and form scum.
Bacteria break down these materials. Wastewater exits the tank as effluent through a pipe into a drain field. Click Here to learn more.
A drain field is a crucial component of a home’s septic system. It filters wastewater before it is dispersed into the soil, and helps keep odors at bay. It also helps keep bacteria and viruses from entering the groundwater supply.
Also known as a leach field, the drain field is a series of perforated pipes buried in the soil. When wastewater leaves the septic tank, solid waste sinks to the bottom and undergoes bacterial digestion. Fats, oils and grease float to the top and form a scum layer. The liquid wastewater, known as effluent, flows out into the drainage field through a pipe. From there, it seeps through the soil and into the water table. The soil acts as a natural filter, removing harmful bacteria and viruses from the wastewater and absorbing nutrient minerals like nitrogen and phosphorus.
While a properly functioning drain field is a vital part of your home’s septic system, it can be damaged by improper care. Never park vehicles or dig trenches over your drain field, as this can cause the soil to compact, reducing its ability to absorb wastewater. Do not plant trees or shrubs too close to the drain field either, as their roots can grow into and clog your drain field.
If you notice sewage backing up into your drains, it is a sign that the drain field is oversaturated. Contact a professional to inspect and repair your septic system as soon as possible.
To avoid oversaturating your septic system, never pour solids down your drains or flush them down the toilet. These include diapers, sanitary products, cat litter, cigarette butts, paper towels, pharmaceuticals, cleaning chemicals and other non-biodegradable materials. If you do have to dispose of these items, put the waste in a container and let it harden before throwing it in the trash. It’s also important to limit how much water you use at one time. If you wash your clothes, dishwasher or run the toilet at the same time, the septic system has to work overtime to deal with the excess waste. This can reduce the lifespan of your drain field and lead to costly repairs down the road.
Inlet and Outlet Tees
The septic tank inlet and outlet tees or baffles are a key part of your home septic system. A baffle is a partial wall that sits in front of the tee and directs wastewater flow in the septic tank. The inlet baffle slows the incoming waste, which reduces disturbance of the settled sludge layer and helps prevent solids from entering the drain field. The outlet baffle reduces turbulence that could carry floating scum and grease into the drainfield, where they would quickly clog it.
The inlet tee of your septic tank should be at least four inches wide, the same size as the septic tank lid opening. The tee should be sloped downward at a rate that is equal to the inlet pipe’s discharge slope. The inlet tee should be connected to the sewer line with a 22 degree elbow that is not longer than the distance from the top of the septic tank’s inlet opening to the bottom of the sludge layer. Using a straight connection on this tee would allow ground water or surface runoff to enter the septic tank through the inlet pipe or at the septic tank cover and flood it, causing a backup in the drainfield.
At the septic tank’s outlet end there is a PVC “T”-shaped fitting, called a sanitary tee, that is open at both ends. This is also a baffle, but it is designed to keep solids, gas bubbles, and floating scum from exiting the tank through the sewage effluent pipe into the drainfield. A sanitary tee works the same way as a concrete baffle but is more durable in a plastic septic tank, which can last much longer than a concrete one.
A septic tank with two compartments does a better job of settling solids. New septic tanks that have this design are required by some local governments. Regardless of the number of compartments, you should have an inlet and outlet baffle at each end to control wastewater flow and protect the drainfield.
You should check your septic tank inlet and outlet baffles regularly to make sure they are still functioning properly. If they aren’t, you will need to replace them.
Vents
When waste and water enters the septic tank, it pushes air along with it. This air needs a way to escape the tank and plumbing system, or it will build up pressure that can stop or reverse the flow of waste in your home. That’s where a set of vents comes in handy. Vents let out gases (like hydrogen sulfide that smells like rotten eggs) and prevent waste from building up too quickly in your pipes.
The septic system vents also help the bacteria in your septic system break down the waste contaminants. The bacteria produce gases as they do this, and these gases need a place to go as well. The vents allow these gases to escape so they don’t create a vacuum that could suck the waste back up into toilets and sinks.
In addition to keeping the septic system working properly, the vents can also help keep your septic tank and septic system maintenance costs down. Without proper ventilation, your septic tank and pipes can suffer from excessive wear and tear, which can lead to costly repairs. By having the vents in the right place, you can avoid these problems and keep your septic system running smoothly for years to come.
If you can’t find a good spot for your septic tank vent, consider talking with your neighbors. If they complain about the odor, you may need to move it somewhere else. Also, be sure to keep the vents clean and clear of any blockages, as this can cause the septic system to work improperly.
You can keep your vents in top shape by getting on a regular upkeep schedule. Check for any obstructions often, and clean out any debris that piles up around the vents or in your yard from time to time. You can even put a charcoal vent filter on the top of your vent pipe to help reduce odors. This is a simple, inexpensive way to make your vents more effective at doing what they’re supposed to do. This will help you stay on good terms with your neighbors, and show them that you care about your community.
Pumping
The septic tank is a large, underground container usually made from concrete or fiberglass. Its job is to hold household wastewater long enough for solid waste to sink to the bottom forming sludge and oil and grease to float to the top forming scum. Compartments and a T-shaped outlet prevent the sludge and scum from leaving the tank traveling to the drainfield area where they can clog and reduce the efficiency of the system. A septic tank should be regularly pumped to remove the accumulated waste and ensure the liquid wastewater (effluent) is free of debris and solids before it exits into the soil absorption field.
If the septic tank is not pumped at regular intervals, the sludge layer will grow until it eventually blocks the inlet and outlet tees. When this happens, the septic system becomes ineffective and will begin to fail. A septic tank should be pumped every 3-4 years depending on the size of the system, the number of people in your home and the use of garbage disposals.
When the septic tank is pumped, the solid waste in the sludge layer is removed and pumped into a truck that disposes of it off-site. The liquid wastewater in the septic tank is then pumped into the septic drainfield where it filters through soil and gravel for final treatment. Keeping the septic tank clean prevents sewage from leaking into the environment, contaminating groundwater and endangering the health of humans and pets.
It is also a good time to inspect the septic system for leaks. This is typically done with a special dye that can show any leaking areas in the system such as a failing baffle or an inlet or outlet pipe. It is a good idea to have the baffles replaced when having your tank pumped to avoid costly repairs in the future.
It is important that the septic tank is easy to access for cleaning and inspection. To facilitate the process be sure to clear out a pathway to the septic tank, the inlet and outlet ports, the drainfield and any other components of the septic system. It may also be helpful to have a map of the location of your septic tank, drainfield and other features of your property.
