In April 2010 the Environment Agency updated the rules relating to septic tanks. It replaced the requirement for discharge consents with a new regime of environmental permits, or otherwise an obligation to register an exemption. This was not widely advertised, largely because it was in practice unenforceable. The location of private sewage arrangements was unknown and therefore the Agency couldn’t write to the people with them! The obligation to register was therefore suspended pending further consultation (in England at least – they continued to apply in Wales). 

The Environment Agency have now issued new guidelines which maintain the permit requirements, but waive any obligation to register for an exemption, provided that the relevant criteria are satisfied. Broadly these criteria are that the septic tank (or sewage treatment plant) must be installed according to the manufacturer’s specifications and be large enough to handle the amount of sewage expected to be produced. It must meet the British Standard for septic tanks and sewage treatment plants in place at the time it was installed (currently BS EN 12566). There is an obligation to repair or replace the septic tank or treatment plant if it isn’t in good working order and empty it whenever it becomes full (it should be emptied at least once a year even if it’s not full). The company used to dispose of waste sludge must be a registered waste carrier. 

If the septic tank or treatment plant is releasing sewage into the ground (eg, back garden or adjacent land) then a drainage field (infiltration system) must be built around it. The drainage field must meet the British Standard in place at the time of installation (currently BS 6297:2007). If it is in a tidal area, then the top of the pipe that releases the sewage must be below the “low water mark”. 

A permit is still required if the sewage released isn’t domestic; sewage is domestic if it’s from a toilet, bathroom, shower or kitchen of a house, flat or businesses including pubs, hotels and offices. You must apply for a permit if you are releasing more than 2,000 litres of sewage per day into the ground or 5,000 litres per day directly into water. Similarly if you are in a groundwater source “protection zone 1” or within 50 metres of a well, spring or borehole used to supply drinking water or water for food production then you will need to apply for a permit. (It may therefore be necessary to ask neighbours if they take drinking water from a well, spring or borehole) 

From 1 January 2020, a permit will be required in order to release sewage from a septic tank directly into a watercourse. If you currently have a septic tank that releases into a watercourse, the Environment Agency advises that you contact them to discuss what you will need to do. 

The Environment Agency has also introduced further requirements for septic tanks or sewage treatment plants installed after 1 January 2015:

  • If sewage will be released into the ground in ancient woodland or within 50 metres of a special area of conservation, a special protected area, a biological site of specific interest, or a Ramsar site ( a wetland designated to be of international importance), then the Agency asks to be contacted for confirmation of whether or not a permit is needed. The Agency will also tell you if you are in or near one of the designated sensitive areas.
  • It will be necessary to apply for a permit if a new drainage system is to release sewage to water within 50 metres of a chalk river, within 200 metres of an aquatic local nature reserve or aquatic local wildlife site, to ditches or watercourses that don’t usually contain water throughout the year or to lakes or ponds where there is no flow. Likewise a permit will be needed if the discharge is within 500 metres of a freshwater pearl mussel population, designated bathing water area, protected shellfish water, a special area of conservation, a special protection area, a Ramsar site or a biological site of special scientific interest.
  • Finally, septic tanks installed after 1 January 2015 will no longer be able to release sewage directly into a watercourse – a sewage treatment plant must be used. The only exception to this is for discharge into a small number of very fast flowing sections of river. Again the Environment Agency should be contacted for confirmation of whether or not this exception