Septic Tanks: everything you need to know

What are septic tanks?

The purpose of a septic tank is to treat sewage in the location it is produced, as opposed to transporting waste to a treatment plant or moving it through a sewage system. Septic tanks are found in both residential and commercial properties and serve as an underground chamber (made of plastic, fibreglass, or concrete) in which domestic wastewater flows for basic treatment. They act as simple onsite sewage facilities.

Septic tanks are buried or constructed below ground and for this reason it is essential to know the exact location and condition of the tank, especially if you are buying a new property which houses one. Previous owners may have had an ‘out of sight, out of mind’ approach and for this reason septic tanks can easily be forgotten or neglected, resulting in a sewage backing up or surfacing near the tank. If possible, ask the previous owners for their tank maintenance log.

You are responsible for a waste system if:

  • you own the property that uses the system.
  • your property shares the system with other properties (you are jointly responsible).
  • you have an agreement with the owner of the property that you are responsible for the system, for example you’re renting and it’s in your tenancy agreement.

If you are responsible for a septic tank system, it’s vital you keep it in good working order and check that it complies with the 2020 Environment Agency General Binding Rules (GBR).

How does a septic tank work?

Septic tanks collect sewage and wastewater from properties not connected to the mains sewer. A septic tank is designed to settle and retain the waste solids produced from a property.

There are two main types of septic tank setups:

Septic tanks with a soakaway

The principle of a septic tank soakaway is to disperse septic effluent (sewage without a high concentration of solids), into the sub-soil at the site.

The process:

  • Sewage enters the tank via the inlet T pipe and discharges to the lower part of the tank.
  • Gravity separates the solids in the sewage to the base of the tank and via anaerobic biological action, a scum layer forms on the surface.
  • Effluent (liquid with very low solids content) exits via the outlet T pipe.
  • This liquid can enter a second or third chamber before moving through to a soakaway field drainage system.

The drainage field is designed to treat the waste effluent with the action of naturally occurring bacteria. For this process to work successfully, the septic tank must be efficient and the subsoil free draining. Before installing a soakaway system, it is advisable to undertake a percolation test and other measures to ensure the area is suitable.

Septic tanks with no soakaway

The regulations relating to septic tanks changed in January 2020. Under the new Environment Agency General Binding Rules (GBR), any septic tank that discharges into a watercourse must be replaced either by a sewage treatment plant installation, a below-ground drainage field system, or a connection to a public sewer. If you are responsible for the septic tank of this type, you must upgrade the system to comply with the new septic tank regulations in order to avoid contaminating the area and being fined.

How to maintain a septic tank

A poorly maintained septic tank could become a serious health or environmental hazard. For this reason, septic tanks need regular maintenance. It is advisable to learn about your system and keep a maintenance record.

Inspect your tank regularly

Regular checks of your septic tank will identify issues before they become serious problems:

  • Check the effluent to make sure that it’s clear and doesn’t contain any solids.
  • Make sure the water levels in the tank’s system aren’t too high or too low.
  • Ensure there isn’t a strong odour where the water soaks away and that the ground is not saturated.
  • Keep the area around the lid of your tank and the soakaway field free of weeds and other vegetation. Avoid driving or parking over the area.

The sewage and toxic gases held by septic tanks can be extremely dangerous to your health. If you have any doubts about your tank, it is always better to contact a professional drainage company who will be able to advise you on what to do. Never enter a septic tank or leave the lid open.

Pumping out

The septic tank system separates solids from liquids and what can’t be broken down settles as sludge the bottom of the tank. Your system will need to be pumped out, also known as de-sludging, every three to five years. Depending on the use of your tank you may need to de-sludge more or less often. It is always advisable to contact drainage experts who can advise you on pumping out and the general maintenance and state of your system.

Alternatives to septic tanks

There are three alternatives to septic tanks. The most appropriate option for your property will depend on the specifics of the plot and its location. You could:

  1. Replace the septic tank with a sewage treatment plant.
  2. Discharge into a drainage field instead of a water course, following 2020 regulations.
  3. Connect to a public sewer.

How Premier Drainage Solutions can help you

At Premier Drainage Solutions, we can support you with a range of septic tank services, including installing soakaway systems that ensure you comply with the 2020 legislation. We can also undertake a percolation test for your soakaway system.

For more information, speak to a member of our team today on 01268 950050 or e-mail us: [email protected]

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