Septic tanks allow wastewater from a house, apartment building, rural school, or public toilet to be collected and treated before it enters the environment. Without this treatment, septic tank waste can pollute nearby water wells and waterways with bacterial germs and chemical pollutants.
Septic tanks collect gray and black wastewater from toilets, sinks, and garbage disposals. Bacteria decompose the content, with heavy solids settling to the bottom of the tank in a sludge layer and liquid wastewater flowing out through a buried drain field or leach field. Visit Our Website
A septic tank needs to be pumped out regularly to prevent it from filling up. When this happens, wastewater cannot pass through the absorption field without entering the home and becoming a health hazard. Foul, rotten odors coming from drains are often the first sign that the tank is overflowing and needs to be pumped. Lush plant growth in the area of the septic system is another clear indication that it’s time to call in a pro for this messy job.
A typical septic tank is designed with an outlet filter to prevent sludge and scum from entering the soil absorption field. However, if the tank is not pumped out as often as recommended by professional services, the solids can build up and flow into the absorption field. Once in the soil absorption field, the solids can clog and block the flow of wastewater into the soil. This can lead to sewage back up into the home or the failure of the entire septic system.
During the pumping process, professionals remove the floating sludge and scum from the top layer of waste. They then empty the contents of the tank into a truck that pumps them out to the waste management facility. The liquid that remains is known as effluent and is distributed to the soil absorption field by a series of subsurface pipes that are usually bedded in gravel. Once in the soil, the effluent is filtered by soil microbes before it exits into water bodies.
Before the septic service company arrives, be sure that you know where the septic tank is located and what its dimensions are. It’s also a good idea to be familiar with when the last maintenance was done on your system and when the next pumping will be scheduled. This will help you avoid any surprises when the service company comes to perform the work.
If you can, prepare the area by trimming bushes and clearing away any weeds that are growing near your septic tank and drain lines. This can make it easier for septic service workers to locate the septic tank and observation ports. You may even want to draw a map or diagram of your property and mark the locations of these features. This will help the professional quickly determine the location of the septic tank and its components when it is time to have it pumped.
Absorption Fields
After the sewage leaves your plumbing system and flows into your septic tank, it goes to the absorption field, which is made of a network of perforated pipes buried in trenches filled with sand and gravel. It is here that the natural processes of soil and microorganisms treat and break down any remaining pathogens and excessive nutrients in the wastewater before it returns to groundwater.
Once the liquid effluent exits the septic tank, it passes through a distribution device that ensures equal amounts of it go to each pipe in the absorption field. This is usually done with a grid pattern, though some systems use a row of porous rocks. The distribution device can also include a filter that keeps solids out of the absorption field.
The septic tank’s inlet and outlet pipes are designed to prevent the scum layer from plugging the tank inlet or absorption field outlet. These are usually 4-inch-diameter Schedule 40 PVC or cast-iron pipe with baffles or sanitary tees. Six-inch-diameter inspection pipes should be located above these to allow for checking solids levels and clogs. The inlet and outlet pipes should be at least 4 feet from any structures such as the house, fence or landscaping.
Any solids that don’t make it into the septic tank, or sludge and scum layers that build up in the tank can enter the drainfield and cause clogs. This exposes people and pets to disease-causing organisms in sewage. In addition, solids that clog the absorption field can run off into water sources such as lakes, rivers and streams.
The absorption field is the final stage of sewage treatment and must be properly maintained to ensure it works as intended. If you have a conventional absorption field, the soil should be at least 2 feet away from any limiting layer, such as a buried rock, fragipan or creviced bedrock, to accept the sewage. In some areas, the soil’s seasonal high water table may saturate the absorption field and limit its ability to accept wastewater.
If the soil’s high water table is a problem, install interceptor drains to lower or divert the water. In addition, fix any water leaks and reduce household water usage. Also, if possible, divert dripline and downspout water to avoid absorption field.
Inlet/Outlet Tees
Ideally, the tank outlet should be a little lower than the inlet so that wastewater flows through the sludge and scum layers without disturbing them. This helps maximize the tank’s treatment capacity and prevents solids from flowing out into your absorption field. The outlet usually has a T or an elbow with a screen that keeps large floating debris from passing downstream.
The inlet baffle is designed to guide house sewer down a longer path across the septic tank, giving it more time to separate into sludge and effluent. It also prevents toilet tissue and other solids from piling up on the floating scum layer. Without an inlet baffle, these solids could block the inlet pipe and redirect sewage back into the house.
If the inlet tee is clogged by a thick scum layer, a replacement tee is required. In some cases, it might be necessary to install a new septic tank as well.
Likewise, the outlet baffle is designed to stop grease and solids from flowing into the distribution box and leaching field beyond. If this baffle is plugged by floating grease or solids, the system will quickly clog and overflow. This can cause your leaching field to fail.
In order to determine if a septic tank needs to be cleaned, the scum depth and sludge depth must be measured. The best way to do this is to have a professional contractor clean the tank. The contractor will use a high-powered truck-mounted vacuum system to break up the sludge and floatable scum. The resulting liquid will then be removed from the tank and disposed of according to EPA regulations.
If you’re unsure whether or not your septic tank is in need of cleaning, try this simple test: Take a stick and push it down through the manhole opening to reach the bottom of the scum mat. If the stick is more than half of the maximum liquid depth, it’s time for a cleaning. A professional contractor will remove the sludge and floatable solids, then pump out the rest of the septic tank contents.
Tanks with Pumps
Some systems may use a septic tank pump to pressurize the wastewater flow between components. This helps the system work even when waste isn’t being deposited regularly, especially in winter. It also helps keep wastewater in perpetual circulation, reducing the risk of freezing and thawing which can damage septic tanks, plumbing, and drainfields.
A septic tank is a buried water-tight container made of concrete, fiberglass, or polyethylene. It’s designed to hold the wastewater long enough for solids to settle down and form sludge, while oil and grease float to the top and form scum. Compartments and a T-shaped outlet prevent sludge and scum from leaving the tank and traveling to the drainfield area. The liquid wastewater (effluent) then exits the tank through the outlet.
The most important thing you can do to prevent septic tank problems is practice responsible waste disposal. This includes never flushing anything other than toilet paper, human waste, and kitchen and bathroom garbage into your septic system. Items that don’t decompose quickly, such as coffee grounds and tea bags, cigarette butts, diapers, make-up removal wipes, cat litter, and lint from synthetic fibers, can cause septic system problems. And, pouring household chemicals like disinfecting cleaners and antibacterial soaps can kill bacteria that naturally help your septic system function.
Regular septic tank pumping can also help your system last longer. It is recommended that you have your septic tank pumped every three years or sooner, depending on your home’s size and usage. It is also important to have your septic system inspected by a qualified professional at least once a year.
It’s also recommended that you mark the location of your septic tank. This is helpful when it comes time to have your septic tank pumped, so you know where the outlet is. And, don’t plant grass or build structures over the septic tank site. These can inhibit proper wastewater absorption and create costly problems in your yard. Also, you should never enter your septic tank. This is extremely dangerous because of the toxic gasses that can build up inside.