Septic tanks are installed when connection to a mains sewer pipe is not possible. Septic tanks are therefore mostly installed in rural locations.
A septic tank is an underground chamber usually manufactured from plastic or GRP through which domestic wastewater flows for very basic treatment. The septic tank allows the solid waste to settle and then the wastewater flows through the tank, out of the outlet and is then dispersed into a drainage field. Septic tanks are no longer allowed to discharge into surface water such as a watercourse (includes ditch or a stream) as the wastewater is now deemed to be a pollutant. If you need to discharge into surface water you need to obtain permission from the Environment Agency and then install a sewage treatment plant.
The Environment Agency introduced new regulations relating to septic tanks in January 2015, these regulations are called the General binding rules: small sewage discharge to a surface water and were introduced as a response to growing concerns over pollution of water courses. These Regulations aim to make septic tanks and sewage disposal more environmentally-friendly and help minimise the risk of pollution and associated environmental harm. If you have a septic tank installed on your property, it is important that you understand these regulations and take steps to ensure compliance.
What do the new rules mean?
The new regulations mean that your septic tank must meet new, higher standards that offer better protection for the environment. Under the new rules, if you have a septic tank that discharges into a water course (i.e. a river or stream) you must either replace or upgrade your system so that it complies with the new higher standards. This action must be taken by 1 January 2020, or before you sell your property if it is before that date. The Environment Agency can also request that the action is taken sooner if there is evidence that your septic system is causing pollution and damage to the environment.
What do I need to do?
If your septic tank currently discharges into a water course, you must take one of the following steps to ensure that you are compliant with the new regulations:
- The septic tank must be connected to a mains sewer where available.
- A drainage field must be installed so that the septic tank can discharge into the ground. A drainage field is a filtration system involving a series of perforated pipes placed over trenches. They are specially designed to remove contaminants from the liquid that emerges from a septic tank to make it safe for release into the environment.
- The tank should be replaced with a full sewage treatment plant. These produce a non-polluting effluent that can be discharged safely into water courses without the risk of environmental harm.
- You must obtain a permit from the Environment Agency allowing discharge to a water course.
- You must obtain a permit to use a septic tank conversion unit to upgrade your existing tank. However, evidence must be provided demonstrating that the upgraded tank will be the same standard as a full sewage treatment plant.
There are a number of additional responsibilities that you must be aware of if you have a septic tank installed on your property. Under the new regulations:
- Your septic tank must meet the appropriate British Standards in place at the time of installation. The standards applicable for new systems are - BS EN 12566 for small sewage treatment plants and BS 6297:2007 for drainage fields. If the septic tank was installed before 1983 then British Standards don’t apply, so the tank will not meet the required standards and will need replacing.
- Your septic tank must be the appropriate size for your household and waste needs.
- Your septic tank must be installed correctly by a qualified septic tank professional.
- Your septic tank must be properly maintained. This includes emptying the tank regularly to reduce the likelihood of leaks or spillages.
- Any repairs to your system must be carried out by competent accredited person.
If you have a septic tank installed on your property, then it is important to do your research and know what action you need to take to remain compliant once the new rules come into force. If you are unsure of your responsibilities, or whether your planned upgrades will meet the required standards, then you should contact the Environment Agency or local septic tank provider for advice and guidance.