Septic tanks can be a source of bacteria that can contaminate groundwater or household wells. This bacteria can pose a serious health risk, especially to infants and older people.
Whenever you use the toilet or a sink, wastewater flows to your septic tank. The waste materials settle in three layers: heavy solids sink to the bottom and form sludge, oils float to the top and form a scum layer, and the clear liquid between is known as effluent. Click Here to learn more.
A septic tank is an underground tank through which wastewater flows for basic sewage treatment. It is typically used in rural settings that aren’t connected to a municipal sewer system. The septic tank separates solid materials from the wastewater and uses anaerobic digestion to reduce organic waste. The resulting liquid, called effluent, is deposited into the drain field.
Wastewater from toilets, tubs, showers, sinks, washing machines, and dishwashers flows into the main drainage pipe that slopes toward your septic tank. Once inside the tank, wastewater splits into three layers. Fats, oils, and grease float to the top and form the scum layer. Organic wastewater pollutants sink to the bottom and form sludge. A layer of clear water lies between these two. Microorganisms in the septic tank feed on these solids and other contaminants to break them down. This anaerobic process produces gases, such as hydrogen sulfide, which can be odoriferous. The gasses pass through a vent that usually has a mushroom shape and is fitted with a charcoal filter to reduce odors further.
Once the liquid passes through an effluent filter near the septic tank outlet, it’s deposited into the drain field. Gravel and soil in the drain field naturally get rid of bacteria, viruses, and other harmful substances in the wastewater. Keeping the drain field in good condition is essential, as failing to do so can lead to wastewater seepage into groundwater and cause contamination.
The septic tank-soil absorption system is the most common type of onsite sewage treatment. The septic tank removes solids from the wastewater, and the soil absorbs and treats the remaining liquid. Adding a septic tank to a home is often less expensive than installing a municipal sewer system, and it can save on property taxes.
If you’re considering buying a home with a septic system, make your offer contingent on a thorough inspection by a certified septic inspector. They will look for a variety of issues, including proper ventilation and draining. They will also assess the state of the septic tank and drain field to ensure they are functioning properly and not leaking or clogging.
How Does a Septic Tank Work?
A septic tank is a water-tight container made of concrete, fiberglass or polyethylene that holds household waste long enough for solids to sink and float. Heavy solids settle to the bottom of the tank and form sludge, while floatable waste, such as oils and grease, rises to the top of the septic tank and forms a layer of scum. Compartments and a T-shaped outlet prevent sludge and scum from leaving the septic tank and traveling into the drainfield area, where they could clog pipes and contaminate soil. The liquid wastewater (known as effluent) exits the septic tank into a series of perforated pipes buried in your drainage field or soil absorption system.
Wastewater is absorbed through the ground by microbes, which naturally filter and digest contaminants. The septic tank serves as a holding chamber to allow the bacterial digestion process to work before the wastewater is discharged into the drainfield.
When waste leaves your home, it flows into the septic tank through household plumbing connections. The septic tank contains three compartments separated by half walls, with the heaviest solids settling to the bottom and lighter, more volatile substances floating on top. The bacteria in the tank break these wastes down, creating a thick, odorless sludge known as sludge. Oils and grease, which are lighter than water, decompose into a layer of scum at the top of the septic tank.
The middle layer of liquid, known as effluent, exits the septic tank and enters the drainfield via a perforated pipe. A distribution box evenly distributes the effluent among trenches in your drainfield, allowing the gravel and soil to serve as biological filters for untreated wastewater.
Bacteria generate gases as they break down wastewater contaminants, including hydrogen sulfide. These gases must be vented to avoid building pressure that could cause a septic tank to overflow or back up into your house. The gases are released through a vent that usually has a mushroom shape and can be fitted with a charcoal filter to reduce odors.
Proper septic system maintenance is crucial to ensuring your drainage field works properly. Keep children and pets away from the drainage field to avoid injury, and maintain a grassy area over the drainfield to encourage the growth of healthy bacteria that naturally filter the effluent. Also, don’t flush anything that should not go into your septic tank, such as chemicals, disposable wipes or kitty litter.
How Do I Pump My Septic Tank?
Pumping your septic tank is one of the most important tasks to keep up with in your home. Septic tanks need to be pumped about every two to five years. Frequency depends on how many people live in your home and the type of waste that goes into your septic system. If septic tanks aren’t pumped regularly, solid waste can build up in the tank and drainfield. This can cause a clog and backups in your plumbing.
Once septic tank solids settle in the tank, they form three layers: sludge, scum, and water. The sludge layer sinks to the bottom of the tank, the scum layer floats on top, and the water (AKA effluent) layer flows into the drainfield. Occasionally, the sludge layer can grow so large that it overtakes the scum and water layer and spills into your drainage field. This can damage your septic system and soil treatment area. Pumping your septic tank eliminates the sludge, preventing solid waste from entering your drainage field and reducing the need for costly repairs.
A professional will use a truck and special equipment to empty your septic tank. First, the pro will hook a large hose up to your septic tank. Once the hose is hooked up, the professional will start pumping. During the pumping process, the technician will also listen to your tank to assess its health and check the condition of the drainfield.
During the pumping process, you will hear a loud, gurgling sound as the solids are removed from the septic tank. To help break down the sludge faster, the technician may also use a muckrake or other tool to break up solid waste clumps and speed up the removal process.
Once the septic tank is emptied, the professional will clean the inlet and outlet baffles. They will also clean any septic tank filters in your home. It is important to have these filter cleaned often because they can become clogged with debris and allow solids to enter the wastewater stream and the drainfield.
The frequency of having your septic tank pumped can be reduced by limiting what is put into the drain system. Avoid flushing paper towels, non-biodegradable cleaning products, and toxic chemicals down your drains. These things can clog your septic tank and the drainfield, reducing its lifespan and function.
Why Do I Need to Pump My Septic Tank?
Septic systems work as an onsite sewage treatment facility, treating and disposing of household waste. Wastewater goes into the septic tank, where heavier solids sink to the bottom and undergo bacterial digestion. Lighter solids and liquid waste float to the top of the septic tank as scum. Over time, the septic tank will need to be pumped out periodically.
Getting the septic tank pumped will prevent solid waste from flowing out into the absorption field and potentially clogging it up. The septic tank is also a safety measure in case the septic system’s drain line or baffles become completely clogged by solid waste.
It is also a good idea to have your septic tank pumped prior to holding a large party or event that will generate a lot of wastewater. This will prevent the massive volume of waste from overwhelming your septic system and possibly leading to pre-mature field malfunction or worse sewage back up into your home.
While bacteria break down most of the solid waste in your septic tank, there will always be some sludge that accumulates over time. Ideally, homeowners should have the septic tank pumped when there is about 1 foot (12 inches) of sludge in the tank.
Some things you can do to help reduce the need to have your septic tank pumped include using less water (spreading out laundry sessions throughout the week instead of all at once) and limiting the use of toxic chemicals in the house, such as paint thinner, polyurethane, antifreeze, some dyes, pesticides, bleach, and disinfectants.
It is also a good idea to map out your septic system, or at least mark the location of the tank and the system’s components with permanent stakes. This will allow you to avoid accidentally damaging the septic system when doing yard work or performing maintenance on your home. It will also make it easier for septic service technicians to locate the septic tank and access the observation ports. This will minimize the cost of having to locate and uncover your septic tank for pumping.