Rules explainer · England
General Binding Rules for septic tanks in England
A plain-English 2026 guide to the Environment Agency rules, the 2020 changes, permits and what matters when selling a property.
What are the General Binding Rules?
They are conditions that allow qualifying small sewage discharges in England to operate without an environmental permit. If every relevant rule is met, a permit is not normally needed. If the rules cannot be met, the operator must apply to the Environment Agency for a permit.
The operator is usually the property owner, the people who share responsibility for a system, or in some cases a tenant whose written agreement makes them responsible for maintenance.
Septic tank General Binding Rules checklist
Use this as a starting point, then check the full Environment Agency guidance for your system and discharge:
- Identify whether you have a septic tank or small sewage treatment plant.
- Confirm whether the discharge goes to the ground or to surface water.
- Check that the daily discharge is within the applicable limit: normally 2 cubic metres to ground or 5 cubic metres to surface water.
- Make sure the system has enough capacity, is operated correctly and is in good working order.
- Arrange regular maintenance and remove sludge before it exceeds the system's maximum capacity.
- Use a registered waste carrier when sludge is taken away.
- Check that the discharge is not causing pollution and that any additional location rules are met.
- When selling, give the new operator the required written information and available maintenance records.
This checklist is a summary, not a compliance assessment. The rules that apply depend on the system, discharge route, location, volume and when the discharge started.
Ground and surface water are treated differently
Different thresholds and requirements can apply to mixed or non-domestic sewage and larger discharges.
Rules that commonly matter to property sellers
- The system must be correctly maintained and in good working order.
- Problems must be repaired or replaced within a reasonable timescale.
- Sludge must be removed by an authorised waste carrier.
- The discharge must not cause pollution of surface water or groundwater.
- Additional siting and installation rules apply, particularly to newer discharges.
- When the property is sold, written information about the system and discharge must be given to the new operator.
If a septic tank discharges to a watercourse
A septic tank is not allowed to discharge directly to a river, stream, ditch or other surface water. Official guidance says the operator should plan to connect to a mains sewer, replace the septic tank with a small sewage treatment plant, or install a drainage field where appropriate.
The Environment Agency says a reasonable timescale is usually within 12 months, unless pollution makes the work more urgent. If the property is being sold, buyer and seller should agree who will complete the upgrade as a condition of sale.
What changed in 2020?
The General Binding Rules were introduced in 2015. The date 1 January 2020 became important for older septic tanks that discharged directly to a watercourse, because those arrangements needed to be upgraded or replaced.
Current Environment Agency guidance says action should be taken as soon as possible where a septic tank still discharges directly to surface water. Plans should usually be in place to complete the work within 12 months, and sooner where pollution is occurring.
Do the rules apply to existing septic tanks?
Yes. Existing systems must meet the rules that apply to all discharges, including the requirements on pollution, capacity, maintenance, emptying and giving information to a new operator when the property is sold.
Additional requirements depend on when the discharge started. Different rules apply to discharges started before 1 January 2015, those started from that date to 1 October 2023, and new discharges started on or after 2 October 2023.
Can you sell a house if the septic tank does not meet the rules?
A property can still be sold, but the issue should not be ignored or described as compliant without appropriate evidence. The seller must give the new operator written information about the system and discharge.
If a septic tank discharges directly to a watercourse, the buyer and seller should agree who will carry out the necessary replacement or upgrade and record that responsibility as a condition of sale. Discuss legal wording with your conveyancer and technical questions with a competent drainage professional.
Do you need a permit?
You may need an environmental permit if your discharge is too large or cannot meet all the applicable General Binding Rules. The Environment Agency may also require a permit in an environmentally sensitive area. Check the complete official guidance or obtain professional advice for your specific system.
Frequently asked questions
Do all septic tanks need an environmental permit?
No. A permit is not normally needed when every applicable General Binding Rule is met. A permit may be required when the discharge is too large, a location restriction applies or the rules cannot otherwise be met.
Can a septic tank discharge into a ditch or stream?
No. A septic tank must not discharge directly to surface water, including a river, stream or ditch. The usual options are a suitable drainage field, connection to the public foul sewer or replacement with an appropriate sewage treatment plant.
How often should a septic tank be emptied?
Sludge must be removed before it exceeds the system's maximum capacity. Environment Agency guidance says this should normally be at least once a year or in line with the manufacturer's instructions.
What information must be given to the buyer?
The new operator must be told in writing about the system and discharge. Include a description, the location of the main parts and discharge point, changes made, maintenance instructions and available maintenance records.
Does MySepticCheck certify compliance?
No. MySepticCheck helps sellers organise the information they provide and identify gaps. It is not a compliance certificate, environmental permit, physical inspection or legal opinion.
Read the official rules
Preparing to sell?
Read our guide to selling a house with a septic tank, use the practical checklist to see what information to gather, or start a MySepticCheck to organise your property record.
Guidance reviewed 19 September 2026 against current Environment Agency guidance. This summary does not replace the full official rules. MySepticCheck is an information and readiness tool, not a compliance certificate, survey, physical inspection or legal or environmental advice.