Septic Tank Discharge Regulations
What Is a Septic tank?
Septic tanks provide an effective wastewater treatment solution for properties not connected to the mains sewer network. These self-contained units break down household waste through biological decomposition before releasing the treated waste into the environment. As septic sewage is discharged into ground or surface water, all systems must comply with Environment Agency regulations to prevent pollution and safeguard public health.
Understanding the General Binding Rules
The General Binding Rules were introduced on 1 January 2015 to simplify the regulation of small sewage discharges from septic tanks and treatment plants. These rules set out the conditions under which operators can discharge wastewater without needing an environmental permit. The operator is the person responsible for the system, whether the property owner, tenant, or another individual with written responsibility for maintenance. Although registration is no longer necessary, operators must ensure their systems comply with all relevant rules to stay lawful.
Discharge to Ground & Surface Water
Septic tank discharge methods are classified into two categories. Systems releasing treated waste into the ground do so via a drainage field, also called an infiltration system or soakaway, where it naturally filters through the soil. Under the General Binding Rules, properties may discharge up to 2 cubic metres per day into the ground using either a septic tank or a small sewage treatment plant.
Systems discharging to surface waters, such as rivers, streams, or ditches, are subject to stricter requirements. Properties can discharge up to 5 cubic metres per day to surface waters, but only using a small sewage treatment plant, not a septic tank. Existing septic tanks that discharged to surface waters were required to be replaced or upgraded by 1 January 2020. If you are selling a property with such a system, replacement or upgrade must occur before completion of the sale.
Compliance Requirements for Septic Tank Systems
All septic tank systems must comply with the relevant British Standard current at the time of installation and operate according to the manufacturer’s specifications. Maintenance should be performed by a competent person, and waste sludge must be removed by an authorised waste carrier. Sealed septic tank systems, such as cesspits, do not discharge to the environment and therefore do not need to comply with the General Binding Rules, although they must be emptied regularly.
For discharges starting on or after 1 January 2015, both planning permission and building regulations approval are required. New discharges are not allowed if any part of the building is within 30 metres of a public sewer, or if connecting to the foul sewer is reasonably feasible. Discharges in or near designated sensitive areas, including groundwater source protection zones, require an environmental permit from the Environment Agency.
Property Sales & Septic Tank Compliance
When selling a property with a septic tank or treatment plant, the operator must provide written notice to the buyer confirming that a small sewage discharge system is in place. This notice should include a description of the system and its maintenance requirements. Buyers should ensure that the system is in good working order and does not cause pollution. Professional inspections and surveys are recommended to assess the system’s condition and ensure compliance with current regulations.
If a septic tank discharges to surface water, the property sale triggers the requirement to replace or upgrade the system to a compliant sewage treatment plant or installing a drainage field for ground discharge. Systems must also meet capacity requirements, so extensions or additional connections may require recalculating discharge volumes and potential upgrades.
Septic Tank Services & Compliance Support
Exjet provides septic tank emptying, inspections, and maintenance throughout Devon, Cornwall, Somerset, and Dorset. Our skilled engineers help property owners understand compliance requirements and evaluate system conditions. For properties needing upgrades or new installations, we provide professional advice and solutions customised to each site. CCTV drainage surveys can detect potential problems with existing systems, while our civil engineering expertise supports larger projects, including septic tank to sewer connections where feasible.
If a small sewage discharge does not comply with the General Binding Rules, the Environment Agency will usually offer guidance to address the issue. Failure to comply may lead to enforcement action. For more information on the General Binding Rules, visit the Environment Agency guidance.