2. Operations
How to meet the operations requirements in section 2 of your intensive pig and poultry farming permit.
2.1 Permitted activities
You are permitted to undertake the activities described in schedule 1, table S1.1 of your permit.
You must comply with the descriptions and thresholds of each activity.
You must not exceed the permitted numbers of animals reared on site.
If you wish to stock more animals or make changes to your site (such as building new housing) you are likely to need to apply for a variation to your permit. Find out how to:
You cannot register or carry out an exempt waste activity within the installation boundary. You must apply to vary your permit before you carry out any of these activities within the installation boundary. You must still register exempt waste activities that take place outside of the installation boundary.
2.2 The site
Your permit includes the agreed site boundary within which the rearing activities take place. A coloured line shows the installation site boundary.
You must not do any of your permitted activities outside of the boundary line. You need to apply for a permit variation to increase your boundary if you do.
You need to apply for a partial surrender if you want to reduce your site boundary.
2.3 Operating techniques
Your permit includes schedule 1, table S1.2 which references the application form and any supporting documents with the agreed operating techniques. You must operate your farm following these techniques, according to this guidance.
Nitrogen (N) excretion
You must prepare and implement a diet and nutrition plan that reduces nitrogen excretion over the lifecycle of the animals. The plan must also meet the nutritional needs of the animals. This will reduce ammonia emissions. The diet formulation and nutritional strategy must incorporate one or more of the following techniques (BAT 3):
- reduce crude protein content by using an N-balanced diet based on the energy needs and digestible amino acids
- multiphase feeding with a diet formulation adapted to the specific requirements of the production period
- addition of controlled amounts of essential amino acids to a low crude protein diet
- use of authorised feed additives which reduce the total nitrogen excreted
The best available techniques (BAT) associated total nitrogen excreted by your livestock must be below the upper end of the range shown in the following tables. This does not apply to pullets or breeders for all poultry species.
Pigs
| Category | Total nitrogen excretion range (kilograms of nitrogen (N) per animal place per year) |
|---|---|
| Weaners | No more than 4.0 |
| Fattening pigs | 7.0 to 13.0 |
| Sows (including piglets) and farrowers | 17.0 to 30 |
Poultry
| Category | Total nitrogen excretion range (kilograms of nitrogen (N) per animal place per year) |
|---|---|
| Laying hens | 0.4 to 0.8 |
| Broilers | 0.2 to 0.6 |
| Ducks | 0.4 to 0.8 |
| Turkeys | 1.0 to 2.3 |
Phosphorus (P2O5) excretion
You must prepare and implement a diet and nutrition plan that reduces total phosphorus excretion over the lifecycle of the animals. The plan must also meet the nutritional needs of the animals. Pigs that are fed a liquid diet may not be able to reduce phosphorus. The diet formulation and nutritional strategy must incorporate one or more of the following techniques (BAT 4):
- multiphase feeding with a diet formulation adapted to the specific requirements of the production period
- use of authorised feed additives which reduce the total phosphorus excreted (for example, phytase)
- use of highly digestible inorganic phosphates for the partial replacement of conventional sources of phosphorus in feed
The BAT-associated total phosphorus excreted by your livestock must be below the upper end of the range shown in the following tables. This does not apply to pullets or breeders for all poultry species, or to ducks.
Pigs
| Category | Total phosphorus excretion range (kilograms of phosphorus (P2O5) per animal place per year) |
|---|---|
| Weaners | 1.2 to 2.2 |
| Fattening pigs | 3.5 to 5.4 |
| Sows (including piglets) and farrowers | 9.0 to 15.0 |
Poultry
| Category | Total phosphorus excretion range (kilograms of phosphorus (P2O5) per animal place per year) |
|---|---|
| Laying hens | 0.10 to 0.45 |
| Broilers | 0.05 to 0.25 |
| Turkeys | 0.15 to 1.0 |
Nitrogen and phosphorus reporting
You must calculate yearly for each animal place the total nitrogen and total phosphorus excreted in manure using one of the following techniques:
- calculate by using a mass balance of nitrogen and phosphorus based on the feed intake, crude protein content of the diet, total phosphorus and animal performance – the Agriculture and Horticulture Development Board (AHDB) have tools to help you do these calculations
- estimate by using manure analysis for total nitrogen and total phosphorus content
The Environment Agency guidance tells you how to submit nitrogen and phosphorus emissions data from your permitted farm using an online reporting form. This replaces the reporting template included in your permit.
You will need to consider alternative or additional abatement to reduce the levels where you exceed the BAT-associated total nitrogen and phosphorus excreted levels.
For organic livestock, the BAT-associated total nitrogen and phosphorus excreted levels may not apply due to feed restrictions in organic rearing. You should report the nitrogen and phosphorus excretion for your organic livestock. You will need to provide justification to your local Environment Agency officer where you exceed the levels.
Schedule 4 of your permit sets out your reporting requirements.
Housing design and management
To reduce ammonia emissions to air from the livestock housing on your farm, you must use one or more of the techniques listed in sections 2 and 3 of the BAT conclusions. Section 4.7 of the BAT reference document (BREF) describes these techniques in more detail. The housing systems which the Environment Agency considers to be the most frequently used in England are detailed in the emission factor tables.
You will need to meet the BAT-associated emission level (BAT-AEL) associated with the housing type. If your housing does not match any of the descriptions provided, you will need to describe how your housing meets BAT.
There are a few scenarios where the standard ammonia emission factor for some housing types do not meet the BAT-AELs for ammonia. In these scenarios, additional measures such as adjustments to crude protein content of livestock feed or other mitigation techniques will be required to comply with the BAT-AELs.
Where a farm is expanding and goes above the permit threshold, it is considered to be a new installation. Both existing and new buildings in a new installation will need to meet BAT and the BAT-AELs.
Ammonia emissions from pig houses
In this section the Environment Agency refers to the following pig categories:
- production pigs (fattening pigs) – any pig over 30kg excluding sows, including gilts over 30kg that have not been served
- sow – an adult female pig after it has produced its first litter of piglets or a gilt which has been served – this includes dry, weaned and served sows
- farrower – a sow which is between giving birth and weaning piglets – for the purposes of permit numbers these pigs are referred to as sows
Note that when calculating emissions there are different emission factors for sows and farrowers.
To reduce ammonia emissions to air from each pig house, you must use one or more of the following techniques which apply one or a combination of the following principles (BAT 30):
- reduce the ammonia emitting surface
- increase the frequency of slurry (manure) removal
- separate urine from faeces
- keep litter clean and dry
You must have appropriate slurry storage and not be reliant on the capacity in under house pits either in practice or in their storage calculations. Any slurry storage infrastructure must comply with the silage, slurry and agricultural fuel oil (SSAFO) regulations and be sufficient to store slurry during any exclusion periods.
A deep pit housing system, with a fully or partly slatted floor, is where slurry is stored under the slatted flooring and removed infrequently, resulting in a slurry depth of greater than 800mm. For new pig housing, a deep pit system is only BAT if used in combination with an additional mitigation measure. This could be an air cleaning system, slurry acidification or slurry cooling.
For new pig housing, a shallow pit (fully or partly slatted floor) housing system, where slurry is regularly removed to a slurry store, is required to have the infrastructure to facilitate regular slurry removal. Regular means underfloor slurry storage must be removed at least once a production cycle. The depth of the slurry stored must be no greater than 800mm, excluding 300mm of freeboard.
A vacuum system for frequent slurry removal can be achieved using a trailer and vacuum pump or sluice-based system. Vacuum systems can be passive gravity fed. There will need to be enough slurry in the store for it to be removed under gravity or by a pump. The speed at which the pit is filled depends on the weight of the pigs and the stocking density. Where a shallow pit system is in operation, depth of slurry below slats must be maintained below 800mm through regular removal, either during or at the end of each cycle. This can be done through flushing, vacuum removal and scraping.
Ammonia emissions can be reduced through frequent and complete drainage of slurry from the floor of the pit. For new pig housing, where the slurry beneath slatted flooring is removed at least once a week, a 25% reduction to the standard ammonia emission factor for the housing system can be applied.
Mating and gestating sows and fattening pigs can be reared in partially slatted floor housing. This could include systems with bedding over the entire floor and systems with strawed lying and scrape-through areas. The frequency of cleaning the scraped areas should be at least 3 times a week.
Mating and gestating sows, weaners and fattening pigs can be reared in a solid floor, straw based system. Dunging and lying areas should be clearly separated to ensure lying areas are kept clean and dry. Floor space allowance should be calculated to match pigs’ requirements as shortage of space can result in dunging in lying areas. Dunging areas should be cleaned out by scraping at least 3 times a week. Sufficient straw or bedding material should be used to keep the lying area clean and dry and to bind nitrogen to reduce ammonia emissions.
Other techniques which are applicable to all pigs include:
- slurry cooling
- use of a clean air system such as a wet acid scrubber, 2-stage or 3-stage air cleaning system or bio-scrubber, or bio-trickling filter
- slurry acidification
BAT-AELs for ammonia emissions to air from each pig house
BAT-AELs are kilograms of ammonia (kg NH3) per animal place per year.
Mating and gestating sows: 0.2 to 2.7:
- for existing farms using a deep pit in combination with nutritional management techniques the upper end of the BAT-AEL is 4.0
- for farms using straw on a solid concrete floor, the upper end of the BAT-AEL is 5.2
Farrowing sows (including piglets): 0.4 to 5.6:
- for farms using a deep pit with fully or partly slatted floors in combination with nutritional management techniques the upper end of the BAT-AEL is 7.5
Weaners: 0.03 to 0.53:
- for existing farms using a deep pit in combination with nutritional management techniques, the upper end of the BAT-AEL is 0.7
- for farms using straw on a solid concrete floor the upper end of the BAT-AEL is 0.7
Fattening pigs: 0.1 to 2.6:
- for existing farms using a deep pit in combination with nutritional management techniques, the upper end of the BAT-AEL is 3.6
- for farms using straw on a solid concrete floor, the upper end of the BAT-AEL is 5.65
The BAT-AELs may not be applicable to organic livestock production.
Ammonia emissions from houses for laying hens, broiler breeders or pullets
You can apply the following principles to reduce ammonia emissions from poultry houses:
- reduce the ammonia-emitting surface
- remove the manure frequently
- quickly dry the manure
- use surfaces which are smooth and easy to clean
- treat exhaust air by acid scrubbers or bio-trickling filters
- lower the indoor temperature and ventilation as much as animal welfare and production allow
Broiler breeders and pullets do not have a BAT-AEL for ammonia emissions.
To reduce ammonia emissions to air from each house for laying hens, broiler breeders or pullets you must use one or more of the following techniques.
Enriched cage systems
An enriched cage system with belt removal must have manure removal by belts with at least one removal per week with air drying or 2 removals per week without air drying (BAT 31a).
Non-cage systems
A non-cage system using forced ventilation and infrequent manure removal (deep litter with a manure pit), is BAT if used in combination with an additional mitigation measure (BAT 31b). This could be a high dry matter content in the manure or an air cleaning system. This housing type is not acceptable for new housing unless combined with an air cleaning system or an abatement technique which achieves equivalent reductions in ammonia emissions.
A manure pit is any pit where the manure falls into a collection chamber below the level where the birds stand or lay. This could be a pit raised above ground level, below a slatted floor. In most cases the litter will be cleared out infrequently, up to once per rearing cycle.
For existing sites, retrofitting forced ventilation may not be applicable due to excessive costs. Existing sheds that are passively or naturally ventilated are acceptable, providing they are well maintained and meet the BAT-AEL.
Where belt cleaning is used for housing with deep litter with a manure pit, it should be designed and operated to optimise air flow and to maximise drying on the belt.
A solid floor with deep litter system using forced drying of litter with indoor air is applicable to new and existing housing. This applies to systems without a manure pit, and where the manure is not routinely removed using a scraper, belt or other mechanism.
Indoor air recirculation systems can be used to dry the litter and meet the needs of the birds. A ventilation system including continuously managed fans controlling indoor air flow, heat exchangers and heaters can be used. Mechanically opening vents and gable end fans may not be BAT when used in isolation. The heat and ventilation in the shed should be managed to ensure dry, friable well-maintained litter.
Other housing systems include:
- forced air drying of manure via tubes (deep litter with a manure pit)
- forced air drying of manure using perforated floor (deep litter with a manure pit)
- multi-tier system with manure belts
There are some types of existing layer housing which the Environment Agency does not consider to be BAT or meet the standards set out in general management conditions.
Deep litter with manure pit systems on temporary or mobile sites with an elevated slatted floor where the manure drops onto an unlined area on the ground are not BAT. These include mobile systems on skids. These sites are unlikely to meet general management conditions and pose a risk to both groundwater and air pollution.
Old or dilapidated buildings with deep litter with manure pit systems which do not meet the general management conditions are not BAT.
Deep litter on solid floor systems with naturally or passively ventilated sheds with no heating are not BAT.
Temporary or mobile sites where litter is placed directly onto an unlined area on the ground are not BAT. These sites are unlikely to meet general management conditions and pose a risk to both groundwater and air pollution.
BAT-AELs for ammonia emissions to air from each house for laying hens
BAT-AELs are kilograms of ammonia (kg NH3) per animal place per year:
- enriched cage systems: 0.02 to 0.08
- non-cage systems: 0.02 to 0.13
For existing housing that use a forced ventilation system and have infrequent manure removal (deep litter with a manure pit) in combination with a measure achieving a high dry matter content of the manure, the upper end of the BAT-AEL is 0.25.
Ammonia emissions from houses for broilers
To reduce ammonia emissions to air from each house for broilers you must use one or more of the following techniques (BAT 32):
- forced ventilation and a non-leaking drinking system (solid floor with deep litter)
- forced drying system of litter using indoor air (solid floor with deep litter)
- natural ventilation, equipped with a non-leaking drinking system (solid floor with deep litter)
- use of an air cleaning system such as a wet acid scrubber, 2-stage or 3-stage air cleaning system, bio-scrubber or bio-trickling filter
BAT-AEL for ammonia emissions to air from each house for broilers
The BAT-AEL for ammonia emissions to air from each house for broilers with a final weight of up to 2.5kg is 0.01 to 0.08 kilograms of ammonia (kg NH3) per animal place per year.
The BAT-AEL may not be applicable to extensive indoor, free range, traditional free range and free-range – total freedom as defined in Commission Regulation (EC) 543/2008.
Ammonia emissions from poultry houses for ducks
To reduce ammonia emissions to air from each house for ducks, you must use one or more of the following techniques (BAT 33):
- natural or forced ventilation with frequent litter addition (solid floor with deep litter or deep litter combined with slatted floor)
- natural or forced ventilation with frequent manure removal (fully slatted floor)
- use of an air cleaning system, such as a wet acid scrubber, 2-stage or 3-stage air cleaning system, bio-scrubber or bio-trickling filter
Ducks do not have a BAT-AEL for ammonia emissions.
Ammonia emissions from houses for turkeys
To reduce ammonia emissions to air from each house for turkeys you must use one or more of the following techniques (BAT 34):
- natural or forced ventilation with a non-leaking drinking system (solid floor with deep litter)
- use of an air cleaning system such as a wet acid scrubber, 2-stage or 3-stage air cleaning system, bio-scrubber or bio-trickling filter
Turkeys do not have a BAT-AEL for ammonia emissions.
Animal places and animal movements
You must record the number of animal places on your site per calendar year and all animal movements on and off the site. You can use a computer or paper-based system.
Use your record to report to the pollution inventory when required.
Slurry spreading and manure management planning – off-site activity
Spreading of manure and slurry outside of the installation boundary is not considered to be part of the permitted installation. BAT requirements are only relevant when spreading is carried out within the installation boundary.
Your permit contains a condition that requires you to use appropriate measures in the disposal or recovery of manure or slurry to prevent or minimise pollution.
You must keep written evidence of the arrangements in place when you export manure and slurry, such as:
- records of the quantities, date of transfer and destination
- the names and addresses and land acreage available where you export manure and slurry for spreading to land
Where a third party accepts liability for removing manure and slurry from the installation, you should provide confirmation that the third party will ensure that the manure is spread to land in line with the Farming Rules for Water and, where applicable, nitrate vulnerable zones (NVZs).
You must have written contingency plans in place for emergencies or situations where land is unavailable for spreading. These plans could include the use of alternative land for spreading or arrangements for additional storage capacity. The details could be part of your accident management plan.
Slurry spreading and manure management planning – operator owned land
You must ensure that manure and slurry is spread to land in line with the Farming Rules for Water and, where applicable, with NVZs.
You must maintain and implement a manure management plan when you spread manure and slurry on land that you own. You must review this plan every 4 years. The plan should also account of any other manures or materials that are spread.
Record keeping must include:
- nutrient content of manure and slurry applied to each field
- weight of manure and slurry applied to each field
- analysis of manure and slurry – this should include total nitrogen, available nitrogen and total phosphorus and should be completed twice yearly, or once per production cycle where that cycle exceeds 6 months
- soil analysis for total phosphorus every 5 years
The Environment Agency may change the requirements for soil and manure analysis depending on the results. For example, the Environment Agency may reduce analysis if they see consistent results or increase analysis if they see variable results.
For more information see the AHDB model template for a manure management plan.
Where spreading is carried out within the installation boundary, you must prevent or reduce emissions from manure and slurry landspreading. Use the techniques in BAT conclusions 20, 21 and 22 to do this.
You can also find more information on spreading in protecting our water, soil and air.
Biomass boilers
If you have a biomass boiler on your installation, you must make sure that you only use raw materials or fuels that are listed in schedule 2 of the permit. If you use waste wood as fuel it must comply with the waste codes listed in schedule 2 of the permit.
You can dispose of ash from the boiler off-site with other wastes. It may be landspread outside the installation boundary under a U10 or U11 exemption, provided it meets the relevant exemption requirements. If these requirements are not met, an environmental permit will be required.
Specified generator or medium combustion plant
Both the medium combustion plant directive (MCPD) and specified generator controls can apply to generators.
If your site includes a medium combustion plant, you must determine if it is subject to the MCPD requirements. Examples of medium combustion plant are biomass boilers, space heaters, incinerators (carcass and biomass) or generators.
You can check using the guidance on medium combustion plant: when you need a permit.
Waste storage
You can store any waste temporarily at the place of production before it is collected. You must store the waste:
- in a secure place
- not longer than 12 months
This is described in the non-waste framework directive (NWFD) exemption NWFD 2 temporary storage at the place of production. You do not need to register this exemption.
Waste sent off site
You must provide the following information when waste produced at the installation is sent off site to a relevant waste operation:
- nature of the process producing the waste
- waste composition
- waste handling requirements
- hazard classification associated with the waste, if applicable
- waste code
For each load of waste removed from your installation, you need a waste transfer note which includes the following details:
- date
- time
- quantity of waste – for example, number of sacks
- type of waste, including any hazardous properties if necessary
- details of the transferor and the transferee
You can use a season ticket to cover multiple transfers of non-hazardous waste over a period of up to a year. It is good practise to keep a record of each transfer including the date, time and quantity of waste.
Improvement programme
Your improvement programme, if you have one, will be set out in Schedule 1 of your permit.
You must complete the list of improvements by the date specified in your permit or by any other date given in writing by the Environment Agency.
New installations must meet the standards set out in this guidance to get their permit, so are unlikely to have an improvement programme.
Pre-operational conditions
If your permit contains pre-operational conditions, you cannot start operating until you have met them. You must complete these conditions by the date specified.
Go to the next section: 3. Emissions and monitoring.
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