Septic Tanks: Some of your common questions answered

As an Irish-owned company, we're proud of being able to install the very best septic tanks and wastewater recycling systems all over Ireland. Due to our expertise, our customers often have questions, particularly regarding septic tanks. To make this information more accessible to our clients, we have included the most common questions below. If you have any more questions, then please get in touch with us today.

How do septic tanks work?

Septic tanks are an essential sewage system component for homes and buildings not connected to a centralised sewer system. They are designed to treat and dispose of wastewater on-site. Here's how septic tanks work:

Collection of wastewater: All the wastewater generated in the building, including water from toilets, showers, sinks, and laundry, flows into the septic tank through a series of underground pipes. The tank is typically made of concrete, fibreglass, or plastic and is buried in the ground.
Separation of solids and liquids: Once inside the septic tank, the wastewater undergoes a natural separation process. The solid waste and heavier particles settle at the bottom of the tank, forming a layer of sludge, while lighter substances like oil and grease float to the top, creating a scum layer. The remaining liquid, effluent, is located in the middle layer.

Anaerobic digestion: In the septic tank, anaerobic bacteria thrive and break down the organic matter in the sludge and scum layers. This biological process, called anaerobic digestion, converts solid waste into simpler substances, including gases (such as methane), liquids, and a small amount of residual solid material.

Effluent treatment: The liquid effluent, which is relatively straightforward and free of solids, exits the septic tank and enters the drain or leach fields. The drain field comprises a network of perforated pipes buried in gravel-filled trenches or beds. The effluent is evenly distributed over the drain field, percolating through the gravel and surrounding soil.

Soil filtration and treatment: As the effluent seeps into the soil, it undergoes further treatment through a natural process called soil filtration. The soil acts as a biological filter, removing harmful bacteria, viruses, and other contaminants from the effluent. The treated water gradually recharges the groundwater or may be absorbed by plant roots.

How are septic tanks emptied?

Septic tanks must be emptied or pumped out periodically to remove the accumulated sludge and scum layers. The pumping frequency depends on factors such as the tank size, the number of occupants in the building, water usage, and local regulations. Generally, septic tanks require pumping every 3 to 5 years, but it can vary.

Here's an overview of the process involved in emptying a septic tank:

Hire a professional: It is recommended to hire a licensed septic tank service provider for pumping and emptying the tank. These professionals have the equipment and expertise to perform the task safely and efficiently.

Locate the tank: The service provider will locate the access points to the septic tank. In some cases, there may be multiple access points, such as manholes or inspection ports, depending on the tank's design.

Inspect the tank: Before pumping, the technician may inspect the tank to assess its condition, check for any signs of damage, and ensure proper functioning.

Pumping process: The service provider will use a vacuum truck or a pump truck equipped with a large hose to remove the septic tank's contents. The hose is inserted through the access point into the tank.

Sludge and scum removal: The pump creates suction, pulling out the sludge from the bottom and the scum from the top of the tank. The solid waste (sludge) and the floating debris (scum) are sucked into the truck for disposal.

Thorough cleaning: Once most of the waste is removed, the technician may use water to rinse the tank and eliminate all the remaining debris.

Proper disposal: The waste collected from the septic tank is transported by the service provider to a designated treatment facility or disposal site. The disposal methods comply with local regulations and environmental standards.

How deep are septic tanks buried?

Septic tanks are typically buried at a depth that allows for proper functioning and protection from external factors. The depth at which septic tanks are buried can vary depending on several factors, including local regulations, soil conditions, groundwater levels, and frost lines in colder regions. However, a standard guideline suggests that septic tanks are buried at a depth ranging from 2 to 4 feet (0.6 to 1.2 meters) below the ground surface.

In Ireland, how much does installing septic tanks cost?

The cost of installing a septic tank in Ireland can vary depending on several factors, including the size and type of the septic tank, site conditions, accessibility, and any additional components or systems required. Please reach out to our offices today to discuss a septic tank installation quote on your property. 

If you have any more questions on septic tank installations, please get in touch with our offices today.