Installing an off-mains drainage system may seem overwhelming when considering the various legal requirements involved. Regulations cover everything from the appropriate tank type for a property to allowable discharge locations and acceptable ground conditions.
Below, you can find a summary guide to the General Binding Rules that pertain to Septic Tanks and Sewage Treatment Plants. Alternatively, click the link to review the relevant Government Regulations.
The new septic tank regulations were introduced by DEFRA and the Environment Agency on January 1st, 2015. Known as 'The General Binding Rules', these new rules simplify the regulations for septic tanks and small sewage treatment plants. The General Binding Rules specify the conditions that must be met to use these systems without an Environmental Permit. Failure to comply with these rules requires the system owner to apply for a Permit or upgrade/replace the existing system to meet the required standards."
From January 1st, 2020, it is now mandatory to replace any septic tank that releases grey (waste) water into the surface water system. Septic tanks that discharge directly into a watercourse or lack proper drainage fields or infiltration systems are deemed non-compliant with the General Binding Rules and will require replacement.
If your septic tank discharges directly to a watercourse, as soon as possible you must either:
If you sell your property, you must tell the new operator (the owner or person responsible for the sewage treatment plant) in writing that a sewage discharge is in place. Include:
You should agree with the buyer or seller who will be responsible for replacing or upgrading the treatment system. You should agree this as a condition of sale.
Your system must meet the relevant British Standard that was in place at the time it was installed. The current standards for new systems are:
If you plan to expand your property or connect another property, it is crucial to ensure that your septic tank or treatment system can handle the increased capacity. Recalculate the maximum daily volume of discharge to determine if the system is adequate. If your discharge exceeds 5 cubic metres (5,000 litres) per day to the surface water, it is mandatory to connect to the public foul sewer, where feasible. Otherwise, you will have to apply for a permit.
You should have your treatment system regularly maintained in line with the manufacturer’s instructions. If these are not available, ask your local maintenance company for advice. You must have your treatment system repaired or replaced if it is not in good working order. For example, this could be if it has:
To prevent your sewage treatment plant from exceeding its maximum capacity, it's essential to get rid of the sludge buildup through regular desludging. As per the manufacturer's instructions, or at least once annually, you should schedule a desludging for your treatment system. It's vital to engage a registered waste carrier company to handle the disposal of your waste sludge.
Any discharge that results in pollution may constitute an offence. The Environment Agency can offer help and guidance to resolve the issue, however, if the discharge persists and continues to cause pollution, the Environment Agency may take enforcement action against the responsible party.
