Insights
If your home is not connected to the mains sewer and you use a septic tank or package treatment plant, the General Binding Rules (GBR) are the legal standards you need to follow. These rules help protect rivers, groundwater, and the wider environment. Understanding and following these rules does not need to be difficult. Here is our simple, straightforward guide.
For further information, click here.
What are the General Binding Rules?
The GBRs are environmental rules set by the Environment Agency to make sure small sewage systems do not pollute local waterways and groundwater. They apply to all small domestic sewage discharges across England.
The rules exist to prevent pollution, protect rivers and groundwater, ensure systems are installed and maintained, and keep homeowners accountable for their wastewater.
If you do not need an environmental permit, you must follow the GBRs instead.
Who do the GBRs Apply to?
The rules apply to you if:
Your property uses a septic tank.
Your property uses a package treatment plant.
Your system discharges to the ground through a drainage field.
Your system discharges to surface water through a treatment plant.
They apply whether your system is old or new, and they also matter when you are selling a property, replacing a failing tank, upgrading or moving a system, or building a property away from mains sewerage.
Which GBRs Apply to me?
The GBRs have changed over time, meaning the year your system was installed affects which standards apply. The first national GBRs took effect in 2015, with further tightening of requirements since. Before 2015, there were no consistent national rules for small sewage discharges, so older systems were built to a range of local or outdated standards.
As a result:
Tanks installed before 2015 were not designed to meet today’s expectations for treatment performance
Systems installed from 1st January 2015 onwards must comply with the original set of GBRs
Any installation from 2nd October 2023 onwards must meet the updated, stricter rules
These changes reflect the growing need to reduce pollution, improve river health, and ensure that all new or upgraded systems meet modern environmental standards. It also means that knowing when your tank was installed is important, as this determines which set of GBRs you are legally required to follow.
What do the Rules Say?
The details below describe the GBRs for existing discharges that were installed before 2015.
Rules that apply to all discharges
The sewage must only be domestic.
The discharge must not cause pollution of surface water or groundwater.
All works and equipment used for the treatment of sewage effluent and its discharge must comply with the relevant design and manufacturing standards, meaning the British Standard that was in force at the time of the installation, and guidance issued by the appropriate authority on the capacity and installation of the equipment.
The system must be installed and operated in accordance with the manufacturer’s specifications.
Maintenance must be undertaken by someone who is competent.
Waste sludge from the system must be safely disposed of by an authorised person.
If a property is sold, the operator must give the new operator a written notice stating that a small sewage discharge is being carried out, and giving a description of the wastewater system and its maintenance requirements.
The operator must ensure the system is appropriately decommissioned where it ceases to be in operation so that there is no risk of pollutants or polluting matter entering groundwater, inland fresh waters or coastal waters.
Rules that apply only to groundwater discharges
The discharge must be 2 cubic metres or less per day in volume.
The sewage must receive treatment from a septic tank and infiltration system (drainage field) or sewage treatment plant and infiltration system.
The discharge must not be within a groundwater source protection zone 1 or within 50 metres from any well, spring or borehole that is used to supply water for domestic or food production purposes.
Rules that apply only to surface water discharges
The discharge must be 5 cubic metres or less per day in volume.
The sewage must receive treatment from a sewage treatment plant.
For discharges in tidal waters, the discharge outlet must be below the mean spring low water mark.
Additional rules for discharges started on or after 1 January 2015
Rules that apply to all discharges
Discharges must not be within 30 metres of a public foul sewer.
For discharges, the operator must ensure that the necessary planning and building control approvals for the treatment system are in place.
Discharges must not be in, or within 50 metres of, a Special Area of Conservation (SAC), Special Protection Area (SPA), Ramsar site, or biological Site of Special Scientific Interest (SSSI), and must not be in an Ancient Woodland.
Rules that apply only to surface water discharges
Discharges must not be in or within: 500 metres of a Special Area of Conservation (SAC), Special Protection Area (SPA), Ramsar site, biological Site of Special Scientific Interest (SSSI), freshwater pearl mussel population, designated bathing water, or protected shellfish water; 200 metres of an aquatic local nature reserve; 50 metres of a chalk river or aquatic local wildlife site.
Discharges must be made to a watercourse that normally has flow throughout the year.
For discharges, any partial drainage field must be installed within 10 metres of the bank side of the watercourse.
Discharges must not be made to an enclosed lake or pond.
Additional rules for new discharges started on or after 2 October 2023
Rules that apply to all discharges
A new discharge shall not use the same outlet as any other discharge if the combined volume of those discharges would exceed the volumetric general binding rules thresholds for groundwater or surface water.
A new discharge shall not be made to a discharge point within 50 metres of any other exempt groundwater activity or water discharge activity.
For more information on the GBRs if your septic tank discharges to the ground, click here.
For more information on the GBRs if your septic tank discharges to surface water, click here.
How to Follow the GBRs
Following the GBRs does not need to be complicated. Below is a detailed, easy-to-understand guide to help homeowners stay compliant.
Know what system you have.
Do you have a septic tank or a package treatment plant (PTP)? A septic tank only provides basic settlement, whereas a PTP gives a higher level of treatment before discharging. Different systems have different requirements under the GBRs; knowing the type of system you have is a great starting point.
2. Check where it discharges.
Does your system discharge to groundwater? If so, the discharge must go into a properly designed drainage field. Alternatively, does your system discharge to surface water, such as a river or stream? In this case, you must have a PTP as septic tanks are no longer allowed to discharge to surface water. Discharging to the wrong place or using the wrong type of system is one of the most common causes of non-compliance and pollution.
3. Book regular maintenance.
Regular emptying and servicing are mandatory under the GBRs. Empty the tank once a year, or according to the manufacturer’s guidance. This removes sludge that would otherwise overflow into the drainage field or watercourse. A poorly maintained system is a significant risk for pollution, and pollution is a direct beach of the GBRs.
4. Look for signs of problems.
Recognising issues early can save money and prevent environmental damage. Inspect the system manually for cracked lids or pipes, blocked outlets and any signs of failure. Failures can present themselves as wet or soggy patches of land near the drainage field, strong smells, slow-running drains, overflow from inspection chambers and the tank filling more quickly than usual.
5. Keep your paperwork.
Good record-keeping is part of demonstrating compliance. Keep a record of your desludging receipts, service reports from engineers, proof of British Standards compliance, details of your drainage field design and records of repairs or upgrades. This documentation is important when you sell your property, show compliance to the Environment Agency and manage long-term maintenance.
6. Upgrade if necessary.
Many older septic tanks will eventually require upgrading as they age and stop performing properly. Some systems automatically need upgrading, especially older septic tanks. You may need to upgrade if your septic tank discharges to a watercourse or soakaway, your system no longer meets British Standards, or there are signs of system failure.
7. Ask for help if unsure.
Wastewater systems can be complex, but qualified engineers can carry out compliance checks if you are uncertain whether your system complies.
Why the GBRs Matter
These rules are not just legal requirements, but they also help stop pollution from reaching our rivers. Failing or outdated systems can leak untreated sewage directly into the ground or waterways, harming wildlife and affecting water quality.
Following the GBRs helps to protect the environment, prevent enforcement action, help keep rivers clean and increase property value and saleability.
