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Rules You Must Follow If Your Septic Tank Releases Liquid To The Ground

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More than half a million homes in the UK have septic tanks. They are very common in rural properties. If your house is not connected to the mains sewer, your sewage will go to a septic tank.

This is an underground tank where the solids sink to the bottom and the liquid flows out and soaks through the ground. Or, your sewage will go to a small sewage treatment plant. Which is a part mechanical system that treats the liquid so it’s clean enough to go into a river or stream.

General Binding Rules

With this in mind, there are general binding rules in place to ensure that septic tanks are regularly emptied and maintained. These rules were first introduced in 2015. But the regulations came into force for both new and old septic tanks from 1st January 2020.

Discharges from septic tanks directly to watercourses are not allowed under the general binding rules.

Generally speaking, the rules are designed to reduce the level of pollution from sewage in British watercourses. The government wants to end the practice of septic tanks discharging directly into a local watercourse, such as a river or stream.

What Are The New Rules?

If your septic tank was built and in use after 31st December 2014, it must have an upgrade to comply with new regulations. Furthermore, if your existing septic tank empties into a watercourse, you need to ensure it has a small sewage treatment plant to treat any waste first.

As an operator of a septic tank, you must follow these rules;

Your sewage must be domestic in nature, for example, from a toilet, bathroom, shower or kitchen.

  • Your sewage must not cause pollution

  • You must use an infiltration system if releasing to the ground. For this, you must apply for a permit if you release or ‘discharge’ to a well, borehole or other deep structure.

  • You also need a permit if you discharge more than 2 cubic metres per day. Or, if you discharge in a groundwater source protection zone.

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How do I Comply With the New Regulations?

You will need to do one of two things. Either replace your tank for a sewage treatment plant. Or, install a drainage field. Any works to drainage are subject to building regulation applications.

How Can I Replace The System?

Essentially, if you need to replace your system to comply with the regulations, you can do one of the points below.

  • You can connect to a mains sewer, where available.

  • Or install a drainage field (infiltration system) so the septic tank discharges into the ground.

  • You can replace your system with a small sewage treatment plant.

  • Or, get a septic tank conversion unit, but you will need a permit for this.

What is a Drainage Field?

A drainage field is also known as an infiltration system. It’s a series of pipes with holes placed in trenches and arranged so that the effluent can go through the ground for further treatment. Do not use a soak-away, a well, or a borehole for discharging effluent.

You must either upgrade to a drainage field, or apply for a permit from the Environment Agency so they can assess the risks.

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Who Is Responsible?

The responsibility of compliance for the new regulations lies with the operator of the septic tank. As the operator, you must meet the general binding rules. You are the operator of a septic tank if the following applies to you;

  • You own the property that uses the system.

  • You have a written agreement with the property owner that says you’re responsible for the system’s maintenance. For example, you are renting the property.

  • You own a property that shares the system with other properties.

How to Maintain Your Treatment System

Your treatment system must meet the relevant British Standard in force at the time of installation. Look for the CE mark or the documentation that came with your tank. If your treatment system was put in before 1983, there is no need to do anything, however, you must meet the other general rules.

For example, your system must be large enough to handle the maximum amount of sewage it will need to treat. Additionally, you need to remove any sludge that builds up in your septic tank. As a minimum, this should happen once a year. Moreover, the company you use to get rid of your waste sludge must be a registered waste carrier.

Additional Rules for New Discharges from Systems Installed After January 2015

There are additional rules for new discharges from a septic tank or small sewage treatment plant on or after 1st January 2015. These include checking if there’s a public sewer nearby. You cannot start a new discharge if any part of the system is within 30 metres of a public sewer. Furthermore, you must have building regulation approval if you are planning to install a new septic tank or small sewage treatment plant.

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Selling Your Property and Compliance

Perhaps you are looking at selling your property with a septic tank that discharges directly to surface water. If this is the case, responsibility for the replacement or upgrade of the existing treatment system must be addressed between the buyer and owner. You will need to update your tank. Also, you need to inform the new owner in writing that you’re responsible for the septic tank discharge.

Rules for Discharge in a Groundwater Source Protection Zone 1 (SPZ1)

A groundwater source protection zone is the area around a commercial water supply. Additionally, it is any area with 50 metres of a private water supply for human consumption. You will need a permit if you have an existing discharge or you are planning to start a new discharge to the ground in an SPZ1 zone.

Enforcement and Sanctions

Finally, if there is evidence of pollution, the Environment Agency will ask you to make changes to your system. If you do not comply with the regulations, then you could face enforcement or sanctions from the Environment Agency.

You can view the .Gov website here for more information on General Binding Rules for Small Sewage Discharge to The Ground.

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