Buying a property with a septic tank can be a daunting prospect, especially if you have never come across one before. Will there be a smell? How do I maintain the system? Does the tank need to be emptied and how often? What are the regulations? These are all questions frequently asked by nervous buyers. This article will discuss these issues and aim to reassure those contemplating life with a septic tank and illustrate that a well-maintained system is an efficient, cost effective and environmentally sound method of waste disposal.

What is a septic tank and how does it work?

The septic tank system has been around for a while. Its invention is attributed to the Frenchman Jean Louis Mouras in 1860 and modern tanks still operate using the same principles of nature and technology. A septic tank is a buried container designed to collect sewage and waste water from households that are not connected to mains drainage. Modern tanks are often constructed of fibreglass or polythene although older versions can be concrete or brick and work just as well. Once in the tank, bacterial action breaks down the waste into three layers, solids, effluent and scum. The solids settle at the bottom where microorganisms decompose them. The middle layer of effluent flows out of the tank into the soakaway or drain field and the scum, mostly oils and fats, are retained on the surface forming a crust.

A soakaway or drain field is connected to the septic tank and put simply, is a hole dug in the ground and filled with rubble, stones and gravel which allow water to drain through and percolate back into the earth. Aerobic bacteria thrive in the soakaway and these complete the decomposition of any remaining waste leaving water sufficiently clean to re-enter the water table.

Rules and Regulations

There are some rules and regulations surrounding septic tanks and their operation. These are overseen and administered by the Environment Agency. New regulations called General Binding Rules came into force on January 1st 2020. https://www.gov.uk/guidance/general-binding-rules-small-sewage-discharge...

  It is no longer legal to discharge waste into any kind of surface water. An appropriate drain field must be constructed to minimise environmental impact.

 If you are considering purchasing a property with a septic tank the seller must now provide all details of the septic tank system in writing. These include a full description of the location, the type of system and any changes made to it, together with maintenance details. As part of the changes there are higher standards for new septic tanks and drainage fields and updated rules about the appropriate size of a tank. New rules also cover location and access. Older systems, providing that they discharge into an appropriate soakaway do not need to be replaced, but should a system fail, the replacement must be compliant with the new binding rules. This can all sound rather alarming and potentially expensive. After all, if you are the prospective owner of a property with a septic tank, how do you know what is going on under the garden? A drainage survey using fibre optic camera technology will quickly reveal the condition of pipework and indicate whether you are likely to inherit any potentially expensive problems.

Maintaining a Septic Tank System

A well maintained septic tank, providing that it has been properly installed will give many years of trouble free service.

Bacteria are what make any septic tank system work and these need to be treated with respect. Try to choose chemical free cleaning products and go easy on the bleach. Don’t flush anything other than toilet paper down the loo.
Regular but not frequent emptying of the tank itself, perhaps once per year, will prevent build up of effluent. The formation of a crust on top of the liquid effluent should be encouraged as this helps to control odour.
Pipework will benefit from high pressure water jetting once every five years or so to remove any build up of sludge and ensure that all waste reaches the septic tank.
Consider introducing a bacteria additive. These are live organic bacteria that help to break down the solids formed by the surfactants in modern soaps and detergents.

Domestic septic tanks can be seen as an environmentally friendly waste water treatment option because the process relies on natural bacteria and soakaways or drain fields to break down and filter the sewage. While you may have to be careful with what you put down the drains, the use of a septic tank can increase awareness of your household water usage and encourage more water efficient habits. Careful water usage can reduce bills and with your own independent sewage treatment you will not pay a water company for the disposal of waste water, making septic tanks a cost effective option.

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