Septic Tank Regulations: The 2020 Deadline and the 2023 Update

Septic tank regulations. It’s not an opening phrase that would make many people read on, but if your property has a septic tank, or if you are buying a property with a septic tank, I’m afraid you might need to.

Given what goes into a septic tank, it’s understandable why the Environment Agency is keen to make sure that it stays in the tank, instead of floating down the local stream. So, there are a lot of rules and regulations surrounding septic tanks, from where you can put them, to where the water that leaves the tank can go. Some are best practice guidelines, but others are legislation, and you could find yourself in the equivalent of the contents of your septic tank if you ignore them.

The latest regulations came out in 2015, and are called ‘General binding rules: small sewage discharge to a surface water’. It doesn’t exactly trip off the tongue, but it’s a very important document for many property owners.

Once upon a time, you could ‘discharge’ the separated waste water from within the septic tank through one of two ways:

1. To a drainage field or soakaway system: here, the waste water percolates through holes or slots into the pipework, into the surrounding sub-soils. This provides a form of treatment of the water, and it allows the waste water to disperse safely without causing pollution.
2. To a watercourse: the waste water would flow through a sealed pipe straight to a local watercourse such as a stream or a river.

You are no longer allowed to discharge from a septic tank to a watercourse, or to any other type of soakaway system other than a drainage field. The reason for this is because the ‘quality’ of the waste water is no longer considered clean enough to flow straight into local watercourses or soakaway systems without causing pollution.

Now, this isn’t an entirely new rule. For some years now, property owners have not been allowed to install a new septic tank which discharges to a watercourse. The legislation previously stated that any non compliant drainage systems would need to be upgraded or replaced by 1st January 2020. However, as that date passed, the guidance within the legislation also changed. Here is what the guidance for the General Binding Rules now states:

‘If your septic tank discharges directly to a watercourse, you need to do one of the following as soon as possible:

• connect to a mains sewer
• install a drainage field (also known as an infiltration system) so the septic tank can discharge to ground instead
• replace your septic tank with a small sewage treatment plant

You must have plans in place to carry out this work within a reasonable timescale, typically 12 months’.

You can view the full guidance for the General Binding Rules here.

It is very important to know exactly what type of drainage system exists at a property, and what condition it is in, prior to any purchase. The guidance on the General Binding Rules states:

‘If you are buying or selling a property with a septic tank that discharges directly to a watercourse, you should agree with the buyer or seller who will be responsible for the replacement or upgrade of the existing treatment system. You should agree this as a condition of sale.’

In order to help simplify things for our lovely customers, we have produced a Quick Guide to Septic Tank, Sewage Treatment Plant and Cesspit Regulations.

If you are buying a property with a septic tank, be sure to get a UKDP homebuyer survey undertaken which will make sure that you know exactly what you’re taking on.

If you're unsure whether your system still complies, a compliance survey confirms it and gives you a report.