GBR Information

The definitive guide…

Lancs Tanks’ guide to the Environment Agency’s General Binding Rules for Small Sewage Discharges in England

Listed and explained one by one below are the

Your legal obligations in respect of off-mains sewage and wastewater treatment are explained on numerous pages of the website:

The Environment Agency (EA) is part of the Department for Environment, Farming and Rural Affairs (DEFRA). The EA operates only in England, where its main responsibilities are:

• regulating major industry and waste
• treatment of contaminated land
• water quality and resources
• fisheries
• inland river, estuary and harbour navigations
• conservation and ecology

Regarding water quality and resources, the EA work to reduce or prevent water pollution, preferably before there’s a pollution incident but also as soon as possible after one. If you cause water pollution, knowingly or unknowingly, the EA will act – as its mandate requires it to do – to stop and prevent further pollution. EA staff will try to work with you in the first instance and then against you if you fail to react or cooperate – whether that’s as an individual, as a group of individuals, or as a business.

The EA has jurisdiction over all water resources in England:

• fresh surface waters, e.g. lakes, tarns, streams, rivers and ponds, wherever they are
• marine surface waters, e.g. estuaries and coastal waters to 3 miles out
• groundwater, i.e. all water underground (even if it’s 1mm below the surface)

in order to protect and improve them in line with legislation.

The EA uses General Binding Rules to protect water resources from pollution caused by Small Sewage Discharges as a quid pro quo for not having to apply for a permit. In making a Small Sewage Discharge without a permit, by the very fact of making the discharge you agree to be bound by the General Binding Rules. Ignorance of the General Binding Rules is not a defence for not complying with their requirements, in the same way as not knowing the speed limit is 50mph is not a defence against breaking that limit.


1. Where can I discharge my treated sewage to?

  • Under the General Binding Rules, Small Sewage Discharges can be made without a permit to 3 types of “receptor”
    • fresh surface waters, e.g. most commonly streams and rivers, but also inland lakes, tarns, ponds, etc. provided that they’re not enclosed or, if they are enclosed, provided that the discharge was “existing”, i.e. being made, before 2015. For “new” discharges, i.e. that commenced in 2015 or later, to enclosed lakes, tarns, ponds, etc. a permit is needed, see GBR 21 below
    • marine surface waters, e.g. estuaries and coastal waters, to 3 miles out
    • groundwater, i.e. any and all water underground (even if it’s 1mm below the surface), through a drainage field, infiltration field, leachfield, call it what you will, but what it’s most often called, incorrectly, is a “soakaway” (see question 4 below)

2. How much treated sewage effluent can I discharge under the General Binding Rules to one of these receptors?

  • Discharges totalling less than 2000 litres of wastewater per day can be made from a septic tank or from a package sewage treatment plant “to ground”, and therefore sooner or later to groundwater
  • Discharges totalling less than 5000 litres of wastewater per day can be made “to surface waters” from a package sewage treatment plant
  • Calculate how much wastewater your domestic property or group of domestic properties produces (see below for commercial properties)

3. What does 2000 and 5000 litres represent in terms of people’s daily wastewater production?

  • Wastewater production is accepted by the EA to be 150 litres/person/day in a domestic situation
    • 2000 litres equals 13 people’s domestic wastewater production per day
    • 5000 litres equals 33 people’s domestic wastewater production per day


The General Binding Rules explained, in order, one by one. Rules 1-14 apply to ALL discharges, regardless of when they started, rules 15-21 to discharges that started in 2015 or later.


1.The discharge must be 2 cubic metres or less per day in volume [to ground]

  • Wastewater production is accepted by the EA to be 150 litres/person/day in a domestic situation
    • 2000 litres equals 13 people’s domestic wastewater production per day
    • A three-bedroomed is taken to be 5 people; a 4 bedroom house 6 people; a 5 bedroom house 7 people, i.e. the number of people is the number of bedrooms plus 2
    • There aren’t many eleven-bedroomed houses, so a four- and a five-bedroomed house together could drain to a septic tank or a package sewage treatment plant followed by a drainage field
    • For groups of houses that total between 13 and 25 people, you can reduce the number of people by 10%, so you could in fact have, for example, two five-bedroomed houses draining to a septic tank or a package sewage treatment plant followed by a drainage field. SeeBritish Water’s Code of Practice: Flows and Loads – 4: Sizing Criteria, Treatment Capacity for Sewage Treatment Systems for details or call us to find out more.

2.The discharge must be 5 cubic metres or less per day in volume [to surface water]

    • Wastewater production is accepted by the EA to be 150 litres/person/day in a domestic situation
      • 5000 litres equals 33 people’s domestic wastewater production per day
      • Since domestic houses with 33 occupants are rare, a more realistic scenario is 4 three-bedroom houses, classed as 5 people, or P, or PE, each = 20 people, and 1 four-bedroom house, classed as 6 people, and 1 five-bedroom house, classed as 7 people, to total 33 people with a small leeway to account for not all dwellings being 100% occupied all at once.

3.The sewage must only be domestic [to ground and to surface waters]

      • Domestic sewage can be broadly summarised as sewage produced in activities that would normally be expected to occur in a domestic environment, e.g. bathing/showering/washing and personal hygiene, food preparation and cooking, washing up (by hand or with a dishwasher), going to the toilet, cleaning, laundry, etc. provided that the activities remain in proportion to the domestic scale. For example; a hotel, campsite or BnB, although commercial enterprises, produces domestic sewage, as does a campsite, since the same activities occur in both of these as they do in the home and in more or less the same proportions as in the home. People still eat, wash up, shower, go to the toilet, etc. when they’re camping, or when they stay in a hotel.
      • Where the characteristics of the wastewater differ in volume, strength, composition, etc. from domestic sewage, usually in the pursuit of a single industrial purpose, e.g. a printworks or a chemical plant, it becomes an industrial or trade effluent.

4.The discharge must not cause pollution of surface water or groundwater [to ground and to surface waters]

      • This is the Environment Agency’s catch-all clause – if you pollute any water, anywhere, you’re breaking not only the General Binding Rules (which themselves are part of the Environmental Permitting (England and Wales) (Amendment) (England) Regulations 2014) but a whole host of laws and regulations, the result of which is that you, as either the property owner and/or the plant operator, can be prosecuted. A well-designed, properly constructed, regularly maintained and “respected” treatment system will not pollute.

5.The sewage must receive treatment from a septic tank and infiltration system (drainage field) or a sewage treatment plant and infiltration system [to ground]

      • When you discharge “to ground” through a drainage field, the upstream septic tank or package sewage treatment plant is only part of the whole treatment system; the other part is the drainage field itself.
      • A septic tank separates 20-40% of the pollutants contained in sewage by settlement and flotation; it retains these solids for later removal and disposal elsewhere (see GBR 12). This separation process is called primary treatment. The resulting primary-treated partially clarified liquid flows on into the constructed drainage field where the remaining 60-80% of the pollutants are removed by secondary biological treatment before it reaches any groundwater.
      • The mechanics of this are achieved firstly by distributing the partially clarified liquid from the septic tank as evenly as possible by gravity over an area of ground large enough to accept the flow/volume concerned and secondly by controlling the rate of infiltration of the partially clarified liquid into that ground. Just how quickly or how slowly liquid will soak away into the ground – the ground’s porosity – is a critical factor in working this out. The ground’s porosity is established by carrying out percolation tests.
          • Adequate treatment is assured by carrying out the percolation tests accurately and then constructing the drainage field correctly, using the right materials.
          • Treatment plants offer primary and secondary biological treatment in a single tank. They are far more effective than septic tanks: under test conditions they remove – or, more accurately, convert – broadly speaking, between 80 and 95% of the pollutants in sewage into simpler, less polluting chemical compounds when operating correctly. This is recognised by allowing them a 20% smaller drainage field than a septic tank serving the equivalent number of people. You might think that, given their effectiveness, it should be a greater saving but treatment plants themselves generate organic solids, in the form of dead bacterial husks. These bacterial husks need to be filtered out of the discharge in a drainage field. (It does beg the question why bother with a treatment plant in the first place if you’re discharging to the ground, to which there are a number of responses.)

6.The sewage must receive treatment from a sewage treatment plant [to surface waters]

          • Only the secondary, biologically treated effluent from a package sewage treatment plant is of a high enough quality to be discharged to surface waters (and only then if the plant is regularly maintained and not abused).
          • New septic tank installations are not allowed to discharge to surface waters (and have not been allowed to do so in England for many years).
          • All septic tanks in England that do discharge to a beck, a stream, a river, a pond, a lake or any other form of surface waters, must be upgraded to package sewage treatment plants. The cut-off date for the grace period following the introduction of the legislation in 2010 was thethe beginning of 2020. Specifically, the webpage read:

Discharges from septic tanks directly to watercourses are not allowed under the general binding rules.”

          • If your septic tank discharges to a land- or field drain that discharges to surface waters – and many do, this is classed as a direct connection to a watercourse therefore the septic tank should be replaced.

7.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 [to ground]

8.For discharges in tidal waters, the discharge outlet must be below the mean spring low water mark [to surface waters]

9.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 [to ground and to surface waters]

          • Installing a new septic tank to replace an existing septic tank, installing a package sewage treatment plant to replace a septic tank, installing a package sewage treatment plant to replace another package sewage treatment plant, or constructing a new drainage field to replace a failed drainage field, all require Building Control approval because all are material alterations to controlled services. It should ensure that the work is carried out to a minimum acceptable technical standard and is fit for purpose.
          • When you come to sell your house, you are now asked if you’ve done any work to it. If you have, you need to be able to prove it was done to the regulations in force at the time. If you can’t prove it, you will either have to prove it retrospectively, which is expensive because Building Control may want you to dig things up to see for themselves what’s been done, or you could accept a lower offer price on your property, to the value of proving the works comply, plus perhaps a little for inconvenience. Note that the works will have to comply with current standards and regulations, not the standards and regulations in force at the time the work was carried out. You could, of course, tell “ a little white lie, no harm done” – although if you’re selling your property you’re probably buying another, so you’d have to hope that your vendor hasn’t done the same…
          • As these very words were being written, we were called by someone selling their house. Their replacement drainage field, installed 11 years ago and serving a septic tank, has been built too close to a stream. Their prospective purchaser’s solicitor has noticed this. The vendor wanted to know what to do. All that can be done is to replace the septic tank with a package sewage treatment plant, or build a new drainage field that’s more than 10m from the stream. Approximate cost? From experience, £8,000-10,000 plus VAT. If the caller’s installer had read and followed the requirements in the British Standard BS 6297:2007+A1:2008 Code of practice for the design and installation of drainage fields for use in wastewater treatment it would have saved the caller (and probably himself now) a lot of time, expense and frustration.
          • Most septic tanks are designed, manufactured, tested and approved to BS EN 12566-1:2000
          • Most package sewage treatment plants are designed, manufactured, tested and approved to BS EN 12566-3:2005+A2:2013 Small wastewater treatment systems for up to 50 (persons equivalent), however larger systems are available for caravan sites, schools, office blocks etc. Any treatment plant that is rated at being able to discharge waste for more than 25 people would require a permit application made to the EA and if granted an annual discharge fee is applicable.
          • It is in the home/business owners interests tp ensure your contractor/installer/supplier is both aware and adheres to these standards. Often going for the “cheapest option” results in incorrectly sized/non EA/BW compliant systems that would have to be removed and replaced in order to sell the property.

10.The system must be installed and operated in accordance with the manufacturer’s specification [to ground and to surface waters]

          • Manufacturers produce simple installation guidelines and operation and maintenance (O&M) manuals, all of which need to be observed to maintain warranties offered.

11.Maintenance must be undertaken by someone who is competent [to ground and to surface waters]

          • “Competence” in off-mains wastewater treatment field can be defined as someone who has been trained in and/or has practical experience of, and understands, the mechanical, electrical and, most importantly, the biological processes involved in the treatment of sewage, rather than someone who’s “willing to have a go”, even with the best intentions.

12.Waste sludge from the system must be safely disposed of by an authorised person [to ground and to surface waters]

          • Authorised in this case means having a waste carrier’s licence to transport controlled waste between its source and its legal place of disposal, in this case and for the most part the local municipal wastewater treatment plant. A farmer’s field, via the slurry pit or by immediate application to land, is not considered a legal place of disposal, and makes a mockery of all the measures put in place so far.
          • Desludging the septic tank or treatment plant ensures not only its effective continued operation, it also prevents solids from entering the watercourse and polluting it or from entering the drainage field and blocking it up, causing the partially treated sewage to appear on the ground surface, as tar-like puddles.

13.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 [to ground and to surface waters]

14.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 [to ground and to surface waters]

          • This basically means disconnect and desludge the system if it is to be abandoned so that it cannot be used inadvertently without maintenance in the future. Fill it in with inert material so that it isn’t left as a void in the ground, with no indication at surface level of the dark unpleasant hole below.

15.New discharges must not be within 30 metres of a public foul sewer [to ground and to surface waters]

          • Self-explanatory: always connect to a mains sewer if possible, even way over 30m away.

16.For new discharges, the operator must ensure that the necessary planning and building control approvals for the treatment system are in place [to ground and to surface waters]

          • A new discharge is, as you might expect, one to where a discharge has not been made before. That means an extension to an existing failing drainage field, a new drainage field adjacent to an existing failed drainage field, a drainage field discharge to ground converted to a discharge to surface waters because the drains are backing up (in which case if you have a septic tank then you need to upgrade it to a package sewage treatment plant), moving an existing discharge by more than 10m, increasing the volume of a discharge, e.g, by building an extension with extra bedrooms.
          • Note that it’s the operator’s responsibility to fulfil this rule, not the supplier’s or the installer’s. Good customer service and commercial responsibility dictates that a responsible provider makes the client aware, of course. The EA has a long definition of what an operator is under the GBRs (it’s a little different for larger discharges):
            • “Where general binding rules apply, the person who is responsible for complying with them is called an “operator”. To help make it clear who this person is, the Regulations describe an operator as a person who has control over the operation of a septic tank or sewage treatment system. An “operator” may be (a) an owner of the system, (b) someone who uses it even though the system itself or part of it may be located on neighbouring land or (c) another person e.g. a tenant or leaseholder who agrees to be responsible for the operation and maintenance of the system, through a written agreement with the owner of the land or part of the land. Any written agreement should explain what maintenance means in practice for the facility.
              The new description of where responsibility for compliance lies no longer refers to the occupier of a property. Nor is it dependent upon the physical location of the actual discharge. Instead it places responsibility on the owner of the property or land where the septic tank or treatment plant is located or being used, as being the person in control of a discharge. The onus is on the owner to either operate and maintain the system themselves or have a written agreement with another person for them to be responsible for the operation and maintenance instead.
              The description also accommodates situations where there is more than one operator e.g. where several properties share the same septic tank or treatment plant. The premise is that they all benefit from using the system, so its maintenance is a shared responsibility.”
          • Building Regulations have been covered under General Binding Rule 9, and the guidance there is clear. Planning is a different matter altogether. What follows is more a summary of our experience rather than specific advice and is more to prepare you for what you might have to face.
          • The following is the content of an email received from a Local Planning Authority. It explains the situation very well, hence its reproduction in full. The question was, “Is planning permission necessary to replace a septic tank with a package sewage treatment plant when the only visual change is the type and location of one, possibly two, manhole covers?”
            • “You are correct in that planning permission assesses visual impact where development of or change to buildings is proposed however, there is also a requirement under planning legislation for the Local Planning Authority (LPA) to assess any proposed development. The text below is an extract from the Planning Practice Guidance webpage which clarifies the definition of ‘development’ and includes Engineering Operation (groundworks) within that definition. The installation of a septic tank/sewage treatment plant would fall under this category and as such, would require planning approval.
            • The LPA are responsible for managing the use and development of land and buildings. The overall aim of the system is to ensure a balance between enabling development to take place and conserving and protecting the environment and local amenities. There are a number of different sorts of assessment required but unfortunately, due to the complexities of the legislation and the various kinds of development, it is not possible to give a short summary of these.
            • Extract from ‘Planning Practice Guidance:
            • Planning permission is only needed if the work being carried out meets the statutory definition of ‘development’ which is set out in Section 55 of the Town and Country Planning Act 1990.
            • Development’ includes:
            • building operations (e.g. structural alterations, construction, rebuilding, most demolition);
            • material changes of use of land and buildings;
            • engineering operations (e.g. groundworks);
            • mining operations;
            • other operations normally undertaken by a person carrying on a business as a builder;
            • subdivision of a building (including any part it) used as a dwellinghouse for use as two or more separate dwellinghouses
            • The categories of work that do not amount to ‘development’ are set out in Section 55(2) of the Town and Country Planning Act 1990. These include, but are not limited to the following:
            • interior alterations (except mezzanine floors which increase the floorspace of retail premises by more than 200 square metres)
            • building operations which do not materially affect the external appearance of a building. The term ‘materially affect’ has no statutory definition, but is linked to the significance of the change which is made to a building’s external appearance.
            • a change in the primary use of land or buildings, where the before and after use falls within the same use class.”
          • Another Local Planning Authority was asked to refer us to the source of the following statement made in a guidance document they published, and if the guidance is still valid. No response was ever received but we have since been told that within a property’s curtilage is a factor in favouring a “permission not required” opinion:
            • “Provision of a new or replacement septic tank or packaged sewage treatment plant may require Planning Permission, unless it is to serve a single dwelling, within the property boundary and not located between the house and the highway.”
          • The same authority, when consulted previously, informally and verbally, on the requirement for planning permission to replace a septic tank with a package sewage treatment plant, said that it wasn’t necessary because it couldn’t really be seen from the very minor adjacent road.
          • It’s quite easy to find planning applications on Local Planning Authority websites solely, and most commonly, for the replacement of a septic tank with a package sewage treatment plant, but the number of planning applications falls far, far short of the number of treatment plants and septic tanks sold in England.
          • The planning process does perform another function: the engagement of “statutory consultees” whose responsibilities to the general public may be impacted.
          • Amongst the statutory consultees relevant to the prevention of water pollution which may be detrimental to human health, wildlife and the environment generally are Environmental Health, the Environment Agency and Natural England.
          • Our best advice is to call your Local Authority Planning Department in your local council, ask for the Duty Planner, explain what you’re intending to do (one could almost say “planning”?) and ask what they think. Failing that, if you go ahead without Planning Permission and it transpires later on that you should have applied for it you can apply for it retrospectively. You might not be granted it, though.

17.New discharges must not be in or within: 500 metres of a Special Area of Conservation (SAC), Special Protection Area (SPA), Ramsar site, biological Site of Special Scientific Interest (SSSI), freshwater pearl mussel population, designated bathing water, or protected shellfish water; 200 metres of an aquatic local nature reserve; 50 metres of a chalk river or aquatic local wildlife site [to surface waters]

          • How could you be sure of any of the above? Applying for planning permission should ensure consultation with the necessary bodies, but you or your architect might want to know what you’re facing. We use Defra’s Magic mapping system. It will give you a very good indication of features that may be affected by having even treated wastewater discharged to them. It takes a bit of practice to find what’s relevantso you could contact us: we’ll check for youand we’d be happy to hear from you. Or you can contact the EA,We can also prepare and submit your application for a permit to the EA if you don’t have the time or specific experience to do it yourself. If you do want to do it yourself the forms can be found on pages. Beyond that we can advise you what sort of systems are available to meet the treated effluent discharge quality standards that may be required in a sensitive location. It’s sort of what we do…

18. New discharges must not be in, or within 50 metres of, a Special Area of Conservation (SAC), Special Protection Area (SPA), Ramsar site, or biological Site of Special Scientific Interest (SSSI), and must not be in an Ancient Woodland [to ground]

          • See above

19.New discharges must be made to a watercourse that normally has flow throughout the year [to surface waters]

          • Although a package sewage treatment plant removes far more pollutants and contaminants than a septic tank, what comes out of it is by no means Evian, even if it might be “as clear as gin.” It still contains pathogens – disease-causing microorganisms in the form of bacteria and viruses – and enough pollutants and contaminants still to represent a public health risk and cause unpleasant odours and environmental damage if they’re not diluted and transited away by oxygenated, flowing water. It may be that the stinking, stagnant ditch to which you discharge isn’t close enough to your property to affect you but it might be close enough to someone else’s to affect them. Try walking in their shoes for a day. Or their wellies.

20.For new discharges, any partial drainage field must be installed within 10 metres of the bank side of the watercourse [to surface waters]

          • The logic behind this rule is to maintain a distinction between discharges to ground via a drainage field, which require a permit at a lower volume because of the potential impact on groundwater, and discharges to surface waters, which have a higher volume threshold for permitting because of the dilution, transit and oxygenation afforded by flowing water. If you were to install a “seasonal soakaway”, i.e. a slotted pipe in an infiltration trench that leads to a watercourse you’re discharging both to groundwater and to surface water, depending on the seasonal ground conditions. The EA considers that having only the last 10m of a treated effluent discharge pipe as a “partial drainage field” (i.e. slotted pipe) is close enough to the water course to be defined as a discharge to surface waters.

21.New discharges must not be made to an enclosed lake or pond [to surface waters]

          • Even well-treated effluent still has a detrimental effect on the dissolved oxygen content of the receiving water course, i.e. it can still have a negative impact on the “receptor”, especially if it is allowed to build up. In a flowing water course oxygen is continually entrained in the water which allows the bacteria that continue to reduce the pollutant load to respire; in a still lake or pond that doesn’t happen. What oxygen there is is used up quickly and anaerobic processes (they’re the very smelly ones) take over.
          • Nutrients such as nitrates and phosphates in the wastewater facilitate the growth of algae on the surface which, although it produces oxygen in daylight, blocks sunlight to the water below to stop the same process in plants beneath the surface. When the algae dies, as it will, it decays and becomes a source of “organic load” – pollution, in this context – causing eutrophication.

We hope this helps you, whether you’re looking to build a new house without access to mains sewerage, an architect designing someone’s dream home, buying a house with a septic tank or are already the owner of a problematic package sewage treatment plant. If you have any questions or would like some impartial advice on how to treat your wastewater responsibly and effectively please do just get in touch: the benefit of our experience over the phone is free, as is a site visit if you really want one. In England we concentrate our domestic installation work in and around our home county of Lancashire and Cumbria – particularly the South Lakes.