A septic tank is a buried, watertight container usually made of concrete or fiberglass. It holds wastewater until bacteria break down solid materials, which sink to the bottom, forming sludge, and grease, and lighter materials float to the top, forming scum.
The liquid wastewater (effluent) exits the tank through a piping network that links to your drain field or an advanced treatment system. Your household size, usage habits, and the size of your septic tank affect how often you need to have it pumped. Click here to Learn More.
The septic tank is the heart of the home’s wastewater treatment system. This underground tank holds waste water from toilets, kitchens, and bathtubs before it is released into the drain field.
The tanks are made of concrete, fiberglass, or polyethylene and come in various sizes to suit different homes. A septic tank is not to be confused with a sewage tank, which holds untreated sewage and is often referred to as a “holding tank.” A septic tank is a pre-treatment chamber that uses natural and mechanical processes to remove waste and organic material before the water is returned to the ground.
As the wastewater flows into a septic tank, it is divided into three layers by gravity and microorganisms: Solid waste that is heavier than water settles to the bottom of the tank, forming a layer of sludge; oil and grease float to the top, forming a layer of scum; and liquid wastewater (effluent) exits from the middle of the tank. Bacteria in the septic tank breaks down the solid waste, reducing its volume.
Septic systems are designed to operate with very little human intervention beyond regular maintenance and pumping. However, homeowners need to be careful what they flush down the drains. Items like baby wipes, cleaning products, paper towels, tampons and even paint rinses can clog pipes that lead out of the septic tank. If they are not disposed of properly, these materials can lead to septic tank failure and cause wastewater to overflow into the house or yard.
When the septic tank is full, it is pumped and the solids are left in the sludge layer while the liquid waste (effluent) exits through a T-shaped outlet into the absorption field. The effluent goes out to the drain field via pipes that are buried under the soil and run through gravel that acts as a natural biological filter.
Septic tanks can be buried anywhere that is safe, including in a deep pit under the ground or in a trench filled with gravel and soil. A septic tank can also be aboveground in a well-draining area that is away from wetlands or near lakes and rivers. These tanks are often located in suburban or rural areas where sewer systems are not available.
Maintenance
Your septic system uses natural and mechanical processes to treat wastewater before it goes back into the environment. The waste from toilets, showers, tubs, sinks, washing machines and dishwashers runs into a drain line that leads to your septic tank. Heavy materials sink to the bottom of the tank, where anaerobic bacteria break them down, forming sludge. Oils and fats float to the top of the tank, where they form a layer of scum. The clear liquid between the sludge and scum is known as effluent, which flows out of your septic tank into an absorption field or leach field.
This is a series of trenches filled with gravel where wastewater is biologically treated in the soil. The soil aerates the water as it seeps through, and the ground surface absorbs any remaining toxins from the system. It’s essential that the absorption field is properly sized and constructed to ensure it will work correctly.
A septic system that isn’t working properly can cause sewage to back up into the home and create odor problems. There are several warning signs to watch for, including:
It’s important to avoid chemical and organic additives that can disrupt the natural breakdown process of your septic system. Doing so can overwork the bacteria inside and make it harder for them to break down solids. This can lead to clogged pipes and a less efficient system.
Regularly check your septic tank for a buildup of sludge, which needs to be pumped out by a licensed professional. In addition, keep grass and other plants away from the septic system to prevent roots from entering and clogging pipes.
Have a septic system inspection and pumping done every two to three years. A septic tank that’s not properly maintained can become overflowing and cause costly damage to the surrounding environment, as well as the property’s plumbing. If you notice a foul smell coming from your toilets or that they’re not flushing easily, call for a septic tank service right away. A septic tank that is overflowing can also be dangerous to the health and safety of your family.
Repairs
If a septic tank fails, it could lead to the contamination of nearby water bodies. Untreated wastewater can harm fish, other wildlife and humans, putting their health at risk. Taking steps to prevent septic tank malfunctions and keeping up with frequent inspections and maintenance help homeowners protect the health of their families and local ecosystems.
Regular septic system maintenance can prevent the need for costly septic tank repairs and replacements. Homeowners can help by practicing mindful waste disposal habits that bar the entry of non-biodegradable materials into the septic system network. They should also refrain from using harsh drain cleaners, which can kill off the bacteria and other natural organisms that aid the septic system’s process of breaking down organic waste.
Inspecting septic tanks regularly and having them pumped out when necessary is vital for the longevity of the system. In addition to preventing waste from overflowing, these regular visits help identify potential issues that may need repair, such as cracks or a faulty lid.
One of the most common septic system problems is sewage backups. If this occurs, it is critical to call a septic tank service right away. This will ensure that the sewage is properly removed before it has the chance to leak into the absorption field and enter your home.
Another sign that it’s time to call in a professional is unpleasant odors around the septic tank or inside the home. These foul odors are caused by the buildup of solid waste within the septic tank or a failure in the drainage system. A plumber can conduct a thorough inspection and determine what the problem is.
When a septic system is failing, it can also cause raw sewage to back up into your home’s toilets, bathtubs and showers. This sewage can contain dangerous bacteria, parasites and viruses that put everyone’s health at risk.
To help prevent septic system failure, homeowners should avoid constructing any structures or parking vehicles over septic tank and absorption field components. They should also map out the location of the septic tank and other system components to avoid damaging them when conducting yard work or performing other home maintenance.
Replacement
A septic tank’s expected lifespan can vary depending on the material, but regular inspections and maintenance will help extend its life. The typical concrete tank lasts 40 years while plastic and fiberglass tanks can serve for 30 or more with proper care. If you have an older tank, it’s important to consider replacement before any problems occur.
A professional septic inspector will complete a thorough assessment of your system to determine what repairs or replacements are needed. During this process, they’ll inspect the drain field as well as the tank to make sure everything is functioning properly. They’ll also check for any signs of septic failure, such as slow draining or foul odors that linger in the home.
Improper household habits can cause clogs and inhibit the effectiveness of the bacteria that break down waste in the septic system. These include putting paper products, wipes, oils and grease, chemicals, paint, medications, and other items that shouldn’t be in the septic system down the drain. This can create a toxic mess and lead to a complete system failure.
Keeping the area around your septic tank, pipes and drain field clean is important for the longevity of your system. It’s recommended to add 8 to 12-inches of mulch, such as straw or leaves, over the soil near the septic tank and drain fields to keep it from compacting. This also helps prevent septic tank failure, which can be costly and dangerous to the health of your family.
In addition to mulch, it’s also helpful to avoid driving or parking vehicles or equipment over the septic tank or system components. It’s also a good idea to map out the location of your septic tank, distribution box and drain field with permanent stakes or markings so you can easily access them when doing yard work or other chores.
If your septic tank fails, sewage will overflow into the surrounding soil and groundwater. This can pose a health risk to you and your family as well as the environment, so if you’re concerned about the condition of your septic system, contact an expert to schedule an inspection.