Septic tank regulations have changed – do you need to replace yours?

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. This is to reduce the pollution that has been flowing into our waterways from private properties – mostly in rural areas, where septic tanks are quite common.

If you are the ‘operator’ of the septic tank (either the homeowner, or a tenant/leaseholder where there is a written agreement that sets out your septic tank maintenance responsibilities), then you must upgrade the system in order to comply with the new septic tank regulations – and it’s necessary to do so as soon as possible, to avoid being fined. It’s not enough to wait until you next sell your property (and having a non-compliant septic tank will certainly impact on any potential sale).

There are three alternatives to septic tanks, though which is most appropriate to your property will depend on the specifics of the plot and its location:

Replace the septic tank with a sewage treatment plant

A sewage treatment plant installation is the way to go if the plot isn’t big enough or suitable for a drainage field, and there isn’t a public sewer nearby. It processes the effluent from a property (or properties, if shared), by separating the solids and liquid, while aeration helps the bacteria to digest the organic material, purifying the effluent that is eventually released.

The resulting effluent is about 95% clean, typically, and may be discharged into a watercourse, ditch or soakaway, with the right Environment Agency permit. Sewage treatment plants do require periodic maintenance and emptying, although the latter is often less frequent than might be the case for an equivalent sized septic tank.

You must have Building Regulations approval for a sewage treatment plant installation, and you may need Planning Permission – check with your local council. It’s also important to make sure that your sewage treatment plant is correctly sized. Of course, design and specification is all part of the sewage treatment plant installation service we offer at Premier Drainage Solutions.

Discharge into a drainage field instead of a water course

If you have sufficient land, then the drainage field option might be the right choice for your property. However, there are three tests that must be done in order to ascertain suitability. Firstly, you need to do a search to find out whether your property is in a Groundwater Protection Zone, in which case you’ll not be able to install a drainage field system.

Secondly, you will need to dig a Trial Site Assessment Hole (TSAH) to find out the position of the groundwater table, so that the drainage field specification can be assured of meeting Building Regulations. Section H2 dictates that the groundwater table should not rise to above 1m of the invert level of the proposed effluent drainage pipes – in other words, it must not be less than 1m below the soakaway pipes, even during the wet season.

Thirdly, there is the percolation test – this will give you the data you need to ensure the specification of the drainage field is of the correct area and so functions correctly. It’s worth bearing in mind that you can’t construct drainage fields close to buildings, trees, watercourses and boreholes, or under driveways or parking area.

Connect to a public sewer

If it’s at all possible, this is the best option – and often the most affordable, provided there is a public sewer within reach. The majority are to be found under public highways, so it’s important to find a company that’s able to do Section 50 works. There are a few different ways to find your nearest public sewer, you can read more about them in our blog ‘How to find the nearest public sewer’.

The next step is to produce a drainage drawing, and submit your Section 106 application, to apply to the water authority for permission to connect to the public sewer, and a Section 50 application to be able to do works within the public highway – this is something we take care of for all our clients. It’s a good idea to choose a contractor who will look after all the compliance paperwork for you, as they’re experienced in ensuring the process goes smoothly and permission is granted first time. Once the works are successfully completed, it’s necessary to provide documentary evidence that the connection is compliant – again, something we do as a matter of course – and once the completion certificate has been issued, the sewer connection is adopted by the local water company.

To find out more about septic tank regulations, as well as our sewer connection, drainage field, and sewage treatment plant installation services – including free advice on your project – call 01268 950050 or send us an email to [email protected].

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