Your Complete Guide to the General Binding Rules for Off-Mains Drainage
Since 2020, the Environment Agency’s General Binding Rules for Small Sewage Discharges has been in force. Hutchinson’s Definitive Guide will help you to understand how the new rules apply to your property or business.
British Water Accredited Engineers
Wastewater experts since 1973
Work with multiple manufacturers
What are the General Binding Rules and how do they effect you?
If you own or live in a property with either its own or a shared septic tank or sewage treatment plant then the new general binding rules might apply to you. Our guide will help you understand the rules and how they might affect you.
The Environment Agency (EA) is part of the Department for Environment, Farming and Rural Affairs (DEFRA). The EA’s responsibilities include:
- regulating major industry and waste
- treatment of contaminated land
- water quality and resources
- fisheries
- inland river, estuary and harbour navigations
- conservation and ecology.
The new General Binding Rules for Small Sewage Discharges is part of the EA’s work to protect water resources from pollution caused by Small Sewage Discharges. The rules acts as a quid pro quo for not having to apply for a permit. In making a Small Sewage Discharge without a permit, you are 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 was as not knowing the speed limit is not a defence against breaking that limit.
FAQ
Under the General Binding Rules, Small Sewage Discharges can be made without a permit to 3 types of “receptors”:
- 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 rule 21 below.
- Marine surface waters, e.g. estuaries and coastal waters, up 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, leach field, call it what you will, but what it’s most often called, incorrectly, is a “soakaway” (see question 4 below)
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)
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
Outside the home, e.g. in offices, hotels, cafes and restaurants, leisure centres, camping and caravanning sites with toilet blocks and showers, etc., the figure is not 150 litres/person/day: the total volume to be discharged per day must be calculated by site and at peak usage in high season by referring to British Water’s Code of Practice: Flows and Loads – 4: Sizing Criteria, Treatment Capacity for Sewage Treatment Systems, e.g.
- In a rural office, 2000 litres could equal as much as 40 staff’ wastewater production per day – a large office, for a rural location
- In a luxury hotel, 2000 litres could equal as little as 6 guests’ wastewater production per day – a very small hotel, anywhere – just 3 double bedrooms
The purpose of a “soakaway”, as the name suggests, is to allow water to soak away. That’s fine for clean rainwater that needs no treatment but not for wastewater that does.
Rain usually falls more quickly than the ground can absorb it. Impermeable surfaces such as roofs obviously don’t absorb it at all, so it’s carried away through gutters and downspouts to gullies and then to an underground soakaway pit. The soakaway holds the rainwater and allows it to “soak away” into the ground at a rate the ground is able to accept it.
A soakaway has traditionally been a rubble- or gravel-filled pit measuring approximately 1m x 1m x 1m for up to 100m2 of roof area. “Crates” are now often used to create the necessary supported underground void to fill with rainwater. Having a floor area of 1m2 a soakaway offers no dispersal over a wider area to prevent total saturation and thus any form of aerobic wastewater treatment is prevented. Rainwater is clean enough to soak away back into the water table without treatment: sewage isn’t.
“Do crates work for sewage treatment?” No: why would they? It doesn’t matter what the soakaway is filled with, what matters is that a 1m x 1m x 1m soakaway concentrates the flow of water into the ground in a 1m2 area which quickly becomes saturated and therefore cannot support the aerobic microorganisms that digest the contaminants in the sewage.
“What if I use lots of crates in a line?” OK, we’re getting closer. But you need the trench floor area as required in the British Standard for drainage fields. And you need the wastewater to flow along the whole length of a trench, so it’s evenly distributed and no one part of the trench is overloaded. Can you dig a trench with a 1:100-200 fall? By the time you’ve done all this, it’d be cheaper (and more effective) to build a conventional drainage field.
“What about anaerobic bacteria?” Good question. Anaerobic bacteria are about 10 times slower than aerobic bacteria at doing the same job, so the wastewater would need to pass by them 10 times more slowly. But soil doesn’t just contain bacteria: it contains a whole food chain of microorganisms, all of which are aerobic, and it’s their total effort that’s necessary. And in the meantime, you have a soggy, black, foul-smelling wet patch in your garden, over your soakaway.
If a contractor builds you a rainwater soakaway for sewage treatment, you (and not the contractor) are contravening Building Regulations. Does that matter? Well, you’ll be polluting groundwater in contravention of the General Binding Rules (Rule 4 – “Thou shalt not pollute”). When you come to sell your house you either have to spend the money you should have spent in the first place to put it right or accept a lower price from the new purchaser for them to put it right.
If you use a rainwater soakaway in an attempt to treat sewage you will pollute the water table. How would you know? You probably wouldn’t because you can’t see the pollution. How do we know? Experience: we’ve dug them up, see what they look like and know what that means in terms of effective physical and biological treatment.
There is no law to say you can’t drink it, in the same way, there’s no law to say you can’t drink diesel, rancid milk, etc. It’s probably no worse than drinking water from a beck just downstream of a busy farmyard that will contain some partially digested organic matter, Weil’s disease bacteria from rats’ urine, general bacteria that live on sewage, plus viruses and bacteria from the human gut, present in faeces and urine, that are able to survive outside the gut and longer than the retention time of the treatment plant… Does that answer your question? If not, for the avoidance of doubt, no, don’t drink it. It’s not a sound sales argument to say that if a liquid appears clear to the naked eye it’s fit to drink. If you’re determined to drink something unpalatable, the water in the toilet bowl after you’ve flushed contains fewer pathogens and is more easily accessible. As is the phone to call a doctor immediately afterwards.
The General Binding Rules
The General Binding Rules are explained, in order, one by one. Rules 1-14 apply to ALL discharges, regardless of when they started, and rules 15-21 to discharges that started in 2015 or later. To find out more, just click the rules below to expand for more information.
2 cubic meters equals 2000 litres of wastewater production per day. Domestic wastewater production is accepted by the EA to be 150 litres per person a day. This represents approximately 13 people’s domestic wastewater production per day.
See British Water’s Code of Practice for full details or call us to find out more.
Domestic sewage is summarised as sewage produced in activities that would normally be expected to occur in a domestic environment. For example, 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.
The activities should remain in proportion to the domestic scale. For example, a hotel, although it is a commercial enterprise, produces domestic sewage, in more or less the same proportions as in the home. People still eat, wash up, shower, go to the toilet, etc. when they stay in a hotel.
A restaurant produces a higher proportion of food than in the home. However, the characteristics of its wastewater do not present any difficulties for effective treatment provided that other regulatory requirements are met, i.e., the provision and maintenance of a suitably sized and correctly installed grease management system, and that good housekeeping and kitchen management is practised.
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 pizza factory or a paper-making plant, it becomes an industrial or trade effluent.
Are you still unsure – our experienced wastewater engineers are happy to advise you on your wastewater characteristics and requirements. The EA has also put together more detailed information comparing the definition of domestic sewage and trade/industrial effluent (Annex 6, pages 175-179).
This is the Environment Agency’s catch-all clause – if you pollute any water, anywhere, you are breaking not only the General Binding Rules but a whole host of laws and regulations.
The result 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.
See the British Water Code of Practice A guide for users of Small Wastewater Treatment Systems (Package Plants) for what is meant by “respected”: much of it also applies to septic tanks.
This is to protect vulnerable or sensitive (usually drinking) water supplies. You probably know where your own well or borehole is if you have one: Do you know if your neighbours have one, and where it is? It can be found on Defra’s Magic mapping system but it’s a bit complicated to use – call us or the Environment Agency on 03708 506 506 to ask them.
All work that falls within the remit of the Building Regulations should be carried out to the Building Regulations in force, currently Part H2, 2010.
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 Small wastewater treatment systems for up to 50 PT. Prefabricated septic tanks. If you want to install one that’s not, you will have to apply for a permit.
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 PT. Packaged and/or site-assembled domestic wastewater treatment plants. If you want to install one that’s not, you will have to apply for a permit.
Another “appropriate authority” issuing “guidance… on the capacity and installation of the equipment” is British Water, which publishes a number of very useful documents through the work of Package Sewage Plant Focus Group, especially their Code of Practice Flows and Loads – 4 Sizing Criteria, Treatment Capacity for Sewage Treatment Systems endorsed by the Environment Agency.
Draw your own conclusions if your contractor/installer/supplier doesn’t work to these standards or, more disturbing, isn’t even aware of them.
“Competence” in the 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.
Competence can be achieved by attending a British Water Accredited Engineer’s training course. A list of such competent engineers is maintained on the British Water website.
We stress the biological aspect of sewage treatment enormously because that, ultimately, is the purpose of this whole exercise: the vessel, the mechanics, the electrics, the design – everything else just supports an effective treatment process. If the treatment process itself is not working, you want someone who can diagnose what that is and implement some corrective action.
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, usually in black, smelly pools. There’s a useful British Water Code of Practice: Guide to the Desludging of Sewage Treatment Systems.
When a property is sold any solicitor worth their salt will ask for this and any estate agency/panel surveyor worth their salt will realise the impact that a poorly installed, badly maintained system will have on a property’s value.
If you’re buying a house with an on-site sewage treatment system and want to know about its condition before you proceed, contact us. We don’t charge for advice over the phone. We’ve also written a blog piece about septic tanks surveys if you’re buying or selling a house.
A new discharge is, as you might expect, one to which 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, or 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 dictate 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.”
- “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.
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. The ‘Plain English Guide to Planning’ document should assist you in this matter and will, I hope clarify the process.
- 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 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.
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 relevant so you could contact us: we’ll check for you and 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 gov.uk 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…
Even well-treated effluent still has a detrimental effect on the dissolved oxygen content of the receiving watercourse, i.e. it can still have a negative impact on the “receptor”, especially if it is allowed to build up. In a flowing watercourse, 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 die, 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 Northumbria, so Cumbria, Durham, Tyne and Wear, Cleveland, north, east and west Yorkshire and across into Lancashire. Although travelling further afield costs more our national clients tell us that we still offer very good value for money and peace of mind for more involved commercial installations on difficult sites where compliance is critical.
Your legal obligations in respect of off-mains sewage and wastewater treatment are explained on numerous pages of the gov.uk website:
- Septic tanks and treatment plants: permits and general binding rules
- Small sewage discharge to the ground
- Small sewage discharge to surface water
- Sewage discharges: calculator for domestic properties
- Comply with septic tank and sewage treatment plant permits
- Environment Agency enforcement, sanctions and offences
- Enforcement undertaking offer form