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General Binding Rules for Small Sewage Discharges

In January 2015 DEFRA implemented the general binding rules for small sewage discharges.  This helped remove ambiguity from the existing permitting system and exempted many small sewage discharges from the need to be permitted provided the rules were met.


The general binding rules apply to both existing and new small discharges.  The following link takes you to the official DEFRA documents;


From the 2nd October 2023 there are new rules coming into effect, further details of which can be found;


Septic tank ban?  There has been confusion, scaremongering and misunderstanding about the implications of the general binding rules but if your system meets the rules you don't need to worry.  The following are some of the key requirements that need to be met in order to be compliant to the rules;


  • Septic tank with a discharge to drainage field (i.e. constructed of peforated pipes, also known as a soak-away) of less than 2m3/day (typical volume from 4 persons in a house is 0.6m3/day)
  • Treatment plant with a discharge to surface water of less than 5m3/day
  • Discharges to ground must be at least 50m away from a drinking water source
  • The system must be maintained in accordance to the manufacturers' recommendations; for a septic tank this is normally annual emptying, for a treatment plant this is also annual desludging and servicing
  • The removal of solids from the tank must be done by an authorised person and disposed of at an authorised facility
  • If the property is sold the operation of the sewage system must be provided to the new owner
  • The system must not cause pollution.


The above link does provide more detail, including further conditions needed for new discharges but in many situations most people will have little to be concerned about - DEFRA are not banning septic tanks!


However, DEFRA have made it clear that septic tanks that have a direct discharge to water course are illegal from 2020 onwards and it will become illegal to sell a property with this arrangement;


Big fine?  Probably not.  In the first instance if you have a septic tank discharging to surface water it is unlikely that the Environment Agency will turn-up on your doorstep and fine you. In the event that they find out you have a direct discharge they will ask you to stop the activity, and normally in agreement with you, set a date to do so.  If you exceeded this date they might then serve formal notice.  If you exceeded the date set on the formal notice (and were generally being uncooperative) you might then reasonably expect to be fined.  We have extensive dealings with the Environment Agency for non-compliant sites and have only ever found their approach to be measured and considerate.


I've got a septic tank discharging to watercourse, do I have to install a sewage treatment plant, are there any other options?   Not necessarily, there are several other options. These may include a gravity drainage field or perhaps a pumped drainage-field (depending on site suitability and compliance to general binding rules).


Case Environmental can provide further consultancy advice regarding general binding rules and your obligations.  As a consultant we offer completely unbiased, confidential and educated advice.  We are based in the south but cover the whole of the UK.  Our clients range from private home owners and prospective purchasers to  the biggest landowners in the UK.

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