The septic tank is the first step in your home’s wastewater treatment. Heavy masses of solids sink to the bottom, forming sludge, while oil and grease float to the top as scum. Contact Septic Tank Armadale now!
Bacteria in the septic tank break down these materials. Then liquid wastewater (effluent) flows out through perforated pipes into the drain field, where it soaks into the soil, naturally filtering and treating the water.
A septic tank is an underground and watertight container made of concrete, polyethylene, fiberglass or steel. It provides primary wastewater treatment by allowing bacteria to break down organic waste. The tank pipes partially clarified wastewater to a drain field for further treatment and dispersal into the soil.
All sewage from toilets and other household plumbing runs into a main drainage pipe that leads to the septic tank. It is a large concrete box that attaches to the outgoing plumbing pipes from the home. The septic tank has a lid and a vent that are covered by a mushroom-shaped filter to reduce odor.
Septic tanks come in different designs, but most work the same way. They have one or more compartments where the waste is stored for a period of time while the bacteria and yeast break it down. The tank may have a partition wall that separates the liquid and solid materials. The fats, oils and grease float to the top and form a scum layer while the solid materials sink to the bottom and become sludge. Helpful bacteria in the septic tank break down these materials and the liquid waste, called effluent, exits the tank through a pipe to the drain field.
In the drain field, septic tank effluent trickles into a trench of gravel and soil where natural filtering takes place. In sandy and limestone soil areas, the septic tank can be used to treat sewage in lieu of sewer systems.
It is important that only human waste and toilet paper enter the septic system. Putting other wastes in the system can cause clogs and damage the biological process that breaks down waste. Never flush baby wipes, kitty litter, chemicals, medicines or cigarette butts into the system.
If you are considering buying a house with a septic system, ask the owner to schedule an inspection of the tank. The septic tank should be inspected before the purchase is final to ensure it is in good working condition and is safe for a new homeowner. When working on a septic tank, always wear protective clothing and a self-contained breathing apparatus. The gases produced by the septic tank can be dangerous, and lack of oxygen can kill someone within minutes.
Inlet Pipes
The inlet pipe carries household wastewater from the plumbing drains into the septic tank, allowing it to separate into solid and liquid waste. The inlet pipe typically has a small baffle to direct the flow into the tank in a single direction. This allows the solids and oils to settle and be separated from the wastewater so that the wastewater that leaves the septic tank is fully treated. The inlet pipe should be watertight, 4-inch-diameter schedule 40 PVC or other approved pipe and have a slope of 1/4 inch per foot (or 1/8 inch per 100 feet) toward the tank. It should have a 6-inch-diameter inspection opening to allow for cleaning and monitoring of the tank.
The septic tank stores the sewage and provides an environment for anaerobic digestion. During this process, the solids sink to the bottom of the tank, forming sludge. The oils and grease float to the top, forming a layer of scum. Bacteria break down the solids and sludge, producing a clear liquid that exits the tank, known as effluent.
Since the septic tank is the first line of defense against groundwater contamination, the tank should be installed on a permeable site with sandy or loamy soil. The soil should not contain gravel or other rocks that could damage the tank or its components. Fiberglass or composite plastic tanks are less prone to corrosion than metal, but they cost more. A concrete tank is a better choice for sites that are rocky or wet, as it offers a more solid base and requires less digging to install.
It is important to maintain a septic tank that is not overflowing by pumping it once a year. In addition, the inlet and outlet pipes should be checked at least twice a year. If a problem occurs, it should be repaired promptly to avoid costly sewer backups.
The best way to prevent clogs is to keep toxic materials out of the septic system, including coffee grounds, bones, paper towels and facial tissues. These and other non-organic substances can interfere with bacterial action and pollute groundwater. It is also important to never add yeast, enzymes, or other additives to the septic system in hopes of improving its performance. They often don’t work and can actually cause damage to the septic system and pollute groundwater.
Outlet Pipes
Once the solids have settled in the septic tank and anaerobic digestion has occurred, the liquid effluent exits the septic tank through the outlet pipe. This effluent then seeps through the drain field and into the soil, where natural processes further treat the sewage before it re-enters groundwater. It’s important that the outlet pipe be free from clogs and that it is properly connected to the tank to ensure this process occurs as intended.
The inlet baffle prevents toilet tissue and other solids from entering the septic tank, where they can pile up on the floating scum layer and block the flow of wastewater into the tank. The inlet baffle also guides the wastewater to a longer path across the septic tank, giving it more time for separation into sludge and scum.
Without an inlet baffle, septic tank solids would likely exit the septic tank directly into the drainfield without undergoing proper bacterial digestion. This could result in a massive septic tank clog and system failure.
As a safety measure, you should never enter the septic tank without first ensuring it’s empty and that the inlet baffle is working correctly. To check this, simply place a wooden stick into the inlet septic tank opening and push it all the way to the bottom of the sludge layer. Mark the stick where it meets resistance and then insert it again into the inlet opening. The distance between the two marks is the sludge depth.
The outlet pipe, which connects the septic tank to the absorption field, is another vital component of your septic system. The outlet pipe should be free of clogs and directing fully treated effluent into the drain field. The drain field is a network of perforated pipes or trenches buried in the soil that further treat the sewage before it re-enters the water supply.
The outlet pipe should be carefully routed to avoid clogs from nearby trees and other sources of obstruction. If you suspect your septic tank outlet line isn’t functioning as it should, consult a septic tank expert to evaluate the situation and perform any necessary repairs.
Drain Field
A septic tank and drain field work together to store and treat all of the wastewater produced by your household. Wastewater from your toilets (called blackwater) and drains in your kitchen, bathroom, laundry room, sinks, bathtub, and washing machine (called greywater) runs into a main drainage pipe that leads to your septic tank. Solid materials—such as feces, food scraps, and toilet paper—sink to the bottom of your septic tank forming sludge. Oils and grease float to the top, forming scum. Aerobic bacteria in your septic tank break down these solids and turn them into liquid wastewater or effluent. The liquid wastewater is then pumped out of the septic tank into your drain field.
The drain field is a series of trenches filled with gravel or stone that’s designed to filter and disperse your sewage into the surrounding soil. It’s important that the soil in your drain field is non-acidic because acidic soil can corrode metal pipes, shortening the lifespan of your septic system.
In addition to soil type, the drainage field is also dependent on the water table in your area. The water table must be low enough to allow the effluent in your septic drain field to percolate into the ground and into your local water supply.
If your septic system is located in an area with high water tables, you’ll likely experience frequent problems with clogged field lines. This can lead to backups into your home and eventually cause your septic system to overflow.
If you suspect that your drain field is clogged, a professional can clear it using a process called jetting, which involves spraying a high-pressure blast of water through the drain field pipes. Keeping your drain fields clean and free of obstructions will help you avoid a costly septic system replacement or repairs in the future. To help prevent blockages, never pour fats, oils, and grease down the drain or into your toilets. You should also avoid putting large amounts of organic waste such as tree stumps and leaves into your drain field. These solids can clog your drain field pipes and overflow your septic tank.