Do I need an Environment Agency permit to install a sewage treatment plant?
In most instances, you will not require a permit to discharge waste from a domestic sewage treatment plant. However, the following criteria must be adhered to. To make it easier, we have broken down the criteria into:
- Criteria relevant to all discharges (both watercourse and ground)
- Specific criteria for discharges to a watercourse (river, stream or ditch)
- Specific criteria for discharges to ground (a drainage field).
Criteria relevant to both discharges to watercourse and ground:
These criteria must be adhered to regardless of where you discharge your sewage waste to
- Sewage must be domestic in nature. The term “domestic in nature” means that the waste must be toilet, bath, shower, washing up, dishwasher and washing machine water. It can be toilet water from a commercial premise (this would still be classed as domestic in nature) but it cannot be waste water from manufacturing processes.
- The discharge must not cause pollution of surface water or groundwater. You may be adhering to all the rules but if you pollute the land, you can be fined. An example here would be a restaurant, adhering to the general binding rules but not managing the fat and oil from the kitchen, which would overload the treatment plant and cause pollution.
- All works and equipment used for the treatment of sewage effluent and its discharge must comply with the relevant design and manufacturing standards i.e. 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 specification. Each manufacturer produces installation guidelines; these must be adhered to when installing a treatment plant.
- Maintenance must be undertaken by someone who is competent. We would suggest using a British Water qualified engineer to service your sewage treatment system
- Waste sludge from the system must be safely disposed of by an authorised person: the company you use must have the correct waste carriers licence to carry and dispose of septic tank or treatment plant sludge.
- 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 waste water system and its maintenance requirements. It is a good idea to ask your service company to give you a log book and report when servicing your treatment plant. Also, keep all receipts of empties to prove it has been correctly looked after.
- 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.
- New discharges must not be within 30 metres of a public foul sewer. The Environment Agency would prefer all discharges to go to a sewer and treated at a municipal treatment plant. Therefore, there would have to be a very good reason for not doing this if you are within 30 metres of a public foul sewer.
- For new discharges, the operator must ensure that the necessary planning and building control approvals for the treatment system are in place.
Additional criteria for discharges to a watercourse (river, stream or ditch)
- Must be less than 5000L a day – Each person produces 150L per day in a domestic household. You must calculate your max discharge using the number of bedrooms (not how many people are in the property now). 1-3 bedrooms = 5 people (900L), 4 bedrooms = 6 people (1050L) 5 bedrooms = 7 people (1200L). If the discharge is over 5000L you must apply for a permit.
- Sewage must receive treatment from a treatment plant. Anything other than a treatment plant will require a permit. It is unlikely you would be granted a permit if you installed a septic tank, but you may be granted one if you were planning on installing a reed bed or some other form of treatment.
- For discharges in tidal waters, the discharge outlet must be below the mean spring low water mark.
- Discharge must not be within 500m of: a biological site of special scientific interest (SSSI), Special Area of Conservation (SAC), Special Protection Area (SPA), Ramsar site, freshwater pearl mussel population, designated bathing water, or protected shellfish water – keep in mind this doesn’t mean you cannot discharge water, it just means you automatically aren’t adhering to the general binding rules and need to apply for a permit to discharge your waste.
- New discharges must not be within 200 metres of an aquatic local nature reserve or within 50 metres of a chalk river or aquatic local wildlife site. As above, you will need to apply for a permit if you fall into this category. The Environment Agency will then decide whether or not to grant you a permit and what the special conditions are (if there are any).
- Discharges should be to a watercourse that has water flowing throughout the year. If it is a dry ditch, you should install a “seasonal drainage field” to allow the water to percolate into the ground prior to the ditch.
- For new discharges, any partial drainage field must be installed within 10 metres of the bank side of the watercourse. This is to prevent water entering a dry ditch when it should be percolating down through the ground.
- New discharges must not be made to an enclosed lake or pond.
Additional Criteria for discharging to a drainage field:
- Discharge must be less than 2000L per day – This equates to 13 domestic people or less.
- The sewage must receive treatment from a septic tank and infiltration system (drainage field) or a sewage treatment plant and infiltration system. Unlike discharges to a watercourse discharging to the ground can be done via a septic tank.
- 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. If you are not adhering to this condition you will have to apply for a permit, and it is highly likely you will be asked to use a treatment plant or even store water in a cesspit to avoid contamination of groundwater supplies.
- Discharge must not be within 50m of: a biological site of special scientific interest (SSSI), Special Area of Conservation (SAC), Special Protection Area (SPA), Ramsar site, and must not be in an Ancient Woodland.
If you’re considering getting a sewage treatment plant installed, Owls Hall Environmental has a range of products and services to help get you up and running.
Last Update: September 6, 2019