19 Waste codes
19 waste codes are from waste management facilities, off-site waste water treatment plants and the preparation of water intended for human consumption and water for industrial use. Your permit lists the 19 waste codes you can use. You must follow the guidance given in the Before you start section.
19 01 wastes are from incineration and pyrolysis of waste.
19 01 12 Ash from the incineration of pig and poultry carcasses at premises used for agriculture only
You can use this waste if you hold SR2010 No 4 – see table 2.2B
For this waste you must follow the information for 10 01 01 Meat and bone meal ash.
If the ash is produced on the farm from incinerating pig and poultry carcasses and it will be spread on that same farm, then you can:
- mix it with farm manure
- spread it as a fertiliser or soil improver
You must follow the guidance on how to manage ash.
19 01 18 Biochar waste codes
Biochar is the charcoal-like residue left after pyrolysis of organic plant material.
You can use these table 2.2B wastes if you hold SR2010 No 4:
- 19 01 18 Biochar manufactured from untreated wood and plant matter from agriculture, horticulture and forestry, or from vegetable waste from food preparation and processing
- 19 01 18 Biochar manufactured from untreated wood, bark, and cork from the furniture manufacturing and wood processing industries (including untreated sawdust, wood shavings, and wood cuttings, except from particle board)
If you plan to use this waste see review of the potential benefits, costs and issues surrounding the addition of biochar to soil: an expert elicitation approach – SP0576 which provides a link to an assessment of the benefits and issues associated with applying biochar to soil.
You may also be able to use the low risk waste position LRWP 61: Storing and spreading biochar to benefit land.
19 02 wastes are from the physico or chemical treatments of waste including dechromatation, decyanidation, neutralisation.
19 02 03 Cement kiln dust and by-pass dust from cement kilns conditioned with water only
You can use this waste if you hold:
- SR2010 No 4 – see table 2.2B
- SR2010 No 5 – see table 2.2
This waste code refers to non-hazardous cement kiln dust and by-pass dust supplied pre-conditioned with water.
For this waste you must follow the information for:
19 02 04* Cement kiln dust and by-pass dust from cement kilns conditioned with water only
You can use this waste if you hold:
- SR2010 No 4 – see table 2.2B
- SR2010 No 5 – see table 2.2
This waste code refers to hazardous cement kiln dust and by-pass dust conditioned by adding water only.
For this waste you must follow the information for:
- accepting hazardous waste under 2.2 Waste acceptance in Landspreading: how to comply with your permit
- 10 13 12* Cement kiln dusts and by-pass dust only
19 05 wastes are from the aerobic treatment of waste.
If you plan to use any of the 19 05 waste codes then you must:
- know how the waste was produced
- follow the guidance on how to manage organic manures in Landspreading: how to manage soil health
19 05 03 Compost derived from biodegradable waste listed in this table only
You can use this waste if you hold SR2010 No 4 – see table 2.2A.
For this waste you must follow the information for 19 05 03 Compost from source segregated biodegradable waste only.
You must follow the guidance in Landspreading: how to manage soil health for how to manage:
- organic manures
- soil organic matter level and applied agrochemicals
19 05 03 Compost from source segregated biodegradable waste only
You can use this waste if you hold:
- SR2010 No 4 – see table 2.2B
- SR2010 No 5 – see table 2.2
It also includes the waste type composted waste bio-bed material.
You must follow the guidance in Landspreading: how to manage soil health for how to manage:
- organic manures
- soil organic matter level and applied agrochemicals
Benefits and risks
Consider these benefits. It can:
- contain moderate levels of nitrogen, phosphorus and potassium at a pH around neutral
- provide a source of organic matter
- act as a soil conditioner
- improve soil structure and aid drainage
- increase nutrient retention
- decrease soil bulk density and improve workability on heavy soils
- improve water holding capacity especially on lighter soils
- slowly release plant nutrients and increase soil mineralisable nitrogen
Consider these risks. it can:
- cause temporary nitrogen lock-up if it has high carbon to nitrogen ratio
- reduce the effectiveness of herbicides
- increase the likelihood of mineral deficiencies in some cases
- contain significant levels of metals or other contaminants
- cause potential odour problems
- contain inorganic or organic contaminants due to variable waste sources and composition
For additional guidance see Quality protocol: compost.
You can also use BSI PAS 100: Specification for composted materials. You will need to pay for this.
Leaf litter
You must not use leaf litter collected from dedicated road sweeping collections under SR2010 No 4 or No 6.
Leaf litter is not a suitable input material for compost derived from source segregated biodegradable waste. The Environment Agency do not consider this waste stream as source segregated. It may contain contaminants such as metals and hydrocarbons.
You can only use the waste code 19 05 99 Compost derived from non-source segregated biodegradable waste for leaf litter for the reclamation, restoration or improvement of land under SR2010 No 5.
Composted waste bio-bed material
In your deployment application use the waste code and description 19 05 03 Compost from source segregated biodegradable waste only. State if it is composted waste bio-bed material.
Bio-beds are small-scale lined lagoons filled with biologically active organic material to break down non-hazardous pesticide solutions or washings.
The material used within a bio-bed can be made from:
- straw
- composts
- biologically active soil
Benefits and risks
Consider these benefits. It can:
- be a good source of general nutrients nitrogen, phosphorus, potassium and a range of trace elements
- be used as a soil conditioner by adding organic matter
- increase soil organic carbon
- improve water holding capacity
- improve soil structure
Consider these risks. It can:
- contain persistent chemical residues
- reduce the effectiveness of herbicides and other agrochemicals, due to high levels of organic matter
Check that the waste producer has stacked old bio-bed material and allowed it to compost aerobically for at least 12 months before supplying. This is to reduce the concentrations of persistent chemical residues that may be present.
Find further information on bio-beds on the voluntary initiative website. In particular see the pesticide handling area and bio-bed manual.
19 05 03 Compost from source segregated biodegradable waste and sludges from treatment of urban waste water only
You can use this waste if you hold:
- SR2010 No 4 – see table 2.2B
- SR2010 No 5 – see table 2.3
For this waste you must follow the information for:
- co-digestion or co-composting of source segregated biodegradable waste and sewage sludge
- 19 05 03 Compost from source segregated biodegradable waste only
- 19 08 05 Treated sludges from treatment of urban waste water
- sewage sludge in forestry, if applicable
Co-digestion or co-composting of source segregated biodegradable waste and sewage sludge
In your deployment application use the waste code and description 19 05 03 Compost from source segregated biodegradable waste and sludges from treatment of urban waste water only. State if it is co-digestion or co-composting of source segregated biodegradable waste and sewage sludge.
The Environment Agency do not class sewage sludge as a source segregated waste. A treated sewage sludge can be spread:
- under the standard rules permits SR2010 No 5 and SR2010 No 6
- to agricultural land under the Sludge (Use in Agriculture) Regulations.
You can spread a co-treated sewage sludge and source segregated biodegradable waste under SR2010 No 4 and SR2010 No 5. You cannot use this waste under the Sludge (Use in Agriculture) Regulations.
Suitable wastes for co-digestion or co-composting with sewage sludge include:
- source segregated green waste
- sawdust and wood shavings from untreated timber
- shredded untreated timber
For green waste follow the information for 20 02 01 Plant tissue waste from parks only.
For sawdust, wood shavings and shredded wood from untreated timber follow the information given for wood waste under the 03 01 waste code.
For guidance on the waste codes to use for sewage sludge and sludge containing other materials see Waste codes for sewage sludge materials: RPS 231.
Benefits and risks
Consider these benefits. It:
- contains nitrogen and phosphate in significant quantities which will contribute all or part of crop requirement
- will have nitrogen in the composted sludge which will mostly be in mineralisable forms unlike ammoniacal nitrogen which is readily available for plant uptake
- can provide approximately 50% of the phosphate to the crop in the first year
- contains trace elements such as sulphur, magnesium and boron which may be of advantage to the crop
- is a source of organic matter which can improve nutrient retention, water holding capacity and soil structure
- reduces losses through leaching because composted sewage sludge increases its total solids
Consider these risks:
- nutrient loss to surface or groundwater can occur if landspread outside the maximum crop uptake window
- composted sludge applications must not be applied to soils below pH 5.0 and soils between pH 5.0 and 5.2 should only receive composted sludge if justified by an appropriately qualified person
- the waste can cause odour during storage and landspreading
- the waste contains potentially toxic elements and other contaminants which may limit the application rate depending on the receiving soil
Potentially toxic elements and the limits which must be met are given in the Sewage sludge in agriculture: code of practice. These limits apply to this waste not just sewage sludge.
Operational considerations
Check that waste producers have met the requirements of the Sludge (Use in Agriculture) Regulations. See table 3.2 Examples of effective sludge treatment processes in the Sewage sludge in agriculture: code of practice for details of how sludge producers will treat sewage sludge.
You must:
- analyse the resulting compost for pathogens, potentially toxic elements and other contaminants
- demonstrate you can spread it on agricultural land
- spread it in line with the limits given in the Sewage sludge in agriculture: code of practice
You can also use the safe sludge matrix.
Application rate
The application rate must reflect the nutrient requirement of the current or proposed crop for nitrogen and phosphate. You can use the fertiliser recommendations in RB209.
You must in your receiving soil analysis consider any contaminants such as potentially toxic elements that could be present. This may limit the application rate.
You must make sure that you:
- meet the waste acceptance requirements for the biodegradable waste streams
- only accept waste that is suitable for direct use
You must also follow the guidance in Landspreading: how to manage soil health for how to manage:
- organic manures
- pests and diseases
19 05 99 Compost derived from non-source segregated biodegradable waste
You can use this waste if you hold SR2010 No 5 – see table 2.3.
It includes the following waste types:
- compost like output
- leaf litter collected from dedicated road sweeping collections
In your deployment application use the waste code and description 19 05 99 Compost derived from non-source segregated biodegradable waste. State if it is compost like output or leaf litter collected from dedicated road sweeping collections.
You must not use output from autoclave or heat treatments.
You can only use this waste as a soil conditioner or improver. For soil substitutes see 19 12 12 Soil substitutes other than that containing dangerous substances only.
See Using soil substitutes or conditioners and improvers under Section 2 of Landspreading: produce a benefit statement for the difference between soil conditioners or improvers and soil substitutes.
Compost like output
Compost like output comes from the mechanical biological treatment (MBT) of mixed municipal solid wastes. MBT plants use biological treatment processes that include stabilisation and sanitisation by composting or anaerobic digestion or a combination of the 2. The feedstock contains non source-segregated municipal waste sources, such as black bag household wastes. Compost like outputs from MBT plants are made up of organic matter, grits, sands and other inert materials that can include plastic and glass.
If you propose using compost like output waste, it must have been sanitised and stabilised by suitable composting treatment methods.
You must be able to show that the compost like output waste will result in a benefit to the soil. It must be suitable for spreading to land without further treatment.
You must not use compost like output to treat land that you intend to return to agricultural use. This includes forage cropping and grazing.
If you want to spread this waste on land that is, or is likely to be, used for agriculture then you must apply for a bespoke permit.
Benefits and risks
Consider these benefits. It can:
- be a potential source of nutrients
- be used as a soil conditioner as part of a land reclamation or restoration scheme
- contribute to soil organic matter
- reduce the use of manufactured fertilisers as it can contain nitrogen, phosphate, potash and sulphur
Compost like output can result in a risk to the environment and human health when spread on land.
It:
- can cause chemical contamination of food and grazing crops
- result in physical contamination of the soil by glass, metal, plastic, foils
- has long term, cumulative risks to the environment and to the continuing, sustainable use of land from persistent contaminants
- is highly variable in quality
- has a comparatively high carbon to nitrogen ratio, which may result in nitrogen-lock-up when you apply it to land depending on the feedstock and processes
You must check that the waste producers have only input biodegradable material into the composting and anaerobic digestion processes. Where required, pre-treatment must have removed any non-biodegradable fractions.
You must also follow the guidance on how to manage organic manures in Landspreading: how to manage soil health.
There is no specification for compost like output but you can use BSI PAS 100: Specification for composted materials as a general guide. You will need to pay for this.
For further information see:
- MBT of municipal solid waste and the links to further information
- hazards from landspreading wastes: methodology for rapid evidence assessment
- leaf litter in street sweepings: investigation into collection and treatment
19 05 99 Liquor and digestate from aerobic treatment of source segregated biodegradable waste only
You can use this waste if you hold SR2010 No 4 – see table 2.2B.
For this waste use the information for aerobic digestion.
You must also follow the guidance on how to manage organic manures in Landspreading: how to manage soil health.
Aerobic digestion
Aerobic digestion treatment converts waste biologically into a useful product. Bacteria thrive in oxygen-rich environments and break down and digest the waste. During the digestion process, waste is broken down into carbon dioxide, water, nitrates, phosphates, sulphates and biomass.
The main benefits of aerobic biological processes are that many contaminants degrade, rather than the treatment process concentrating them.
Controlled air passes through the waste and is often used as the secondary treatment of sludges and slurries. This produces mineralised sludge. The remaining materials are organic and made up of cell walls and other cell fragments that are not readily biodegradable.
You must know what went into the treatment process. Suitable waste types for aerobic digestion include:
- biological treatment sludges
- source segregated biodegradable wastes
Pre-treatment requirements can include removal of:
- non-biodegradable packaging
- other non-biodegradable fractions
Unsuitable waste types are:
- wastes containing hazardous or toxic contaminants
- non source-segregated wastes – unless the waste is spread on to non-agricultural land
- wastes containing sharps or other physical contaminants
- wastes containing non-biodegradable fractions that cannot be separated by pre-treatment
Benefits and risks
Consider these benefits. It can:
- provide moderate levels of nitrogen, phosphorus and potassium at a pH around neutral
- provide organic matter and condition soil
- has a low carbon to nitrogen ratio giving a net release of nitrogen to the receiving crop
- reduce the biological oxygen demand and chemical oxygen demand of liquors
Consider these risks. It:
- may contain inorganic or organic contaminants
- can cause odour – you will need to inject the liquors from the aerobic digestion process into the soil or incorporate them as you are spreading
- can come from a variety of sources – account for this in your waste analysis
19 06 wastes are from the anaerobic treatment of waste.
Anaerobic digestion
Anaerobic digestion treatment converts waste biologically into a useful product. The bacteria thrive in anoxic (oxygen free) environments and break down and digest the waste. Wastes from anaerobic digestion include whole digestate sludge or separated fractions of digestate fibre (solid) and liquor (liquid).
The waste inputs and how the anaerobic digestion system is managed determines the potential benefit or improvement provided by the digestate. Appropriate monitoring helps establish confidence in the consistency of the digestate.
Check that the waste producer has used suitable wastes. These are:
- wastes listed in annex B of BSI PAS 110 Producing quality anaerobic digestate
- food processing industry waste
- agricultural wastes
- wastes from abattoirs
Pre-treatment requirements can include:
- removal of non-biodegradable packaging
- maceration of the wastes
You must not use:
- wastes containing hazardous contaminants
- non source-segregated wastes – unless the waste is spread on to non-agricultural land
- wastes containing sharps or other physical contaminants
- wastes containing non-biodegradable fractions that cannot be separated by pre-treatment
Benefits and risks
Consider these benefits:
- the fibre may contain moderate levels of nitrogen, phosphorus and potassium
- it can be a source of organic matter and condition the soil
- it has a low carbon to nitrogen ratio giving a net release of nitrogen to the receiving crop
Consider these risks. It may:
- contain potentially toxic elements and other contaminants
- contain physical contaminants
- lead to ammonia volatilisation when surface spread
- have potential for nitrate leaching if applied when crops are not actively growing
- cause odour, notably with the use of the liquor with high trajectory landspreading methods
- come from a variety of sources – account for this in your waste analysis
Potentially toxic elements and the limits that must be met are given in the Sewage sludge in agriculture: code of practice. These limits apply to this waste not just sewage sludge.
Operational considerations
Anaerobic waste pH is typically between pH 6.0 and 8.0.
Readily available nitrogen is the nitrogen that is potentially available for rapid crop uptake. The WRAP report on using quality anaerobic digestate to benefit crops states that 80% of the total nitrogen in food-based digestate is readily available.
Crop available nitrogen is the readily available nitrogen that remains for crop uptake after any losses of nitrogen.
You can assume a 60% nitrogen efficiency for landspreading applications. This is based on the WRAP report on anaerobic digestate to benefit crops and the principles of nitrogen supply and losses in the Nutrient management guide (RB209).
Therefore, 60% of the readily available nitrogen (80% of the total nitrogen) will be available to the crop in the year the waste is applied. This also assumes digestates are landspread to growing crops in the spring.
An appropriate expert such as a Fertiliser advisers certification and training scheme (FACTS) advisor must carry out the nitrogen requirement assessment.
If you plan to landspread anaerobic waste, see:
- Code of Good Agricultural Practice for reducing ammonia emissions
- Using quality anaerobic digestate to benefit crops – contains advice on spreading equipment and reducing ammonia gas emissions to the atmosphere
- Section 2 of RB209 for agronomic references
19 06 03 Liquor from anaerobic treatment of non-source segregated biodegradable waste
You can use this waste if you hold SR2010 No 5 – see table 2.3.
For this waste you must follow the information for:
19 06 04 Whole digestate and fibre digestate from anaerobic treatment of non-source segregated biodegradable waste
You can use this waste if you hold SR2010 No 5 – see table 2.3.
For this waste you must follow the information for:
19 06 05 Liquor from anaerobic treatment of source segregated biodegradable waste
You can use this waste if you hold:
- SR2010 No 4 – see table 2.2B
- SR2010 No 5 – see table 2.2
For this waste you must follow the information for anaerobic digestion.
19 06 06 Whole digestate and fibre digestate from anaerobic treatment of source segregated biodegradable waste
You can use this waste if you hold:
- SR2010 No 4 – see table 2.2B
- SR2010 No 5 – see table 2.2
For this waste you must follow the information for anaerobic digestion.
19 06 06 Whole digestate and fibre digestate from anaerobic treatment of source segregated biodegradable waste and sludges from treatment of urban waste water only
You can use this waste if you hold:
- SR2010 No 4 – see table 2.2B
- SR2010 No 5 – see table 2.3
For this waste you must follow the information for:
19 08 wastes are from wastewater treatment plants.
19 08 02 Washed sewage grit (waste from desanding) only
You can use this waste if you hold SR2010 No 5 – see table 2.3.
Sewage grit is inorganic material removed from the influent at waste water treatment works. It is mainly sand, gravel, road stone and glass.
You can use the de-watered grit for land reclamation. You can only apply it to land previously used for industrial or other developments with no plan to return it to agricultural use. The waste must be a washed sewage grit.
You can use it to give benefit as it provides fine aggregate to the finished soil profile.
There is a risk of it containing potentially toxic elements and other physical contaminants such as glass, rags and plastics.
Potentially toxic elements and the limits that must be met are given in the Sewage sludge in agriculture: code of practice. These limits apply to this waste not just sewage sludge.
You must also follow the guidance on how to manage organic manures in Landspreading: how to manage soil health.
19 08 05 Treated sludges from treatment of urban waste water
You can use this waste if you hold:
- SR2010 No 5 – see table 2.3
- SR2010 No 6 – see table 2.2
Regulatory position statement 231
If you hold SR2010 No 5 or SR2010 No 6 you need to follow Waste codes for sewage sludge materials: RPS 231.
19 08 05 may also be described as sewage sludge, biosolids or bioresources.
You must also see sewage sludge in forestry, if applicable.
Benefits and risks
Consider these benefits. It:
- contains nitrogen and phosphate in large quantities which will meet all or part of the crop requirement
- has approximately 50% of the phosphate the crops need in their first year
- contains trace elements such as sulphur, magnesium and boron which may benefit the crop
- contains organic matter which can improve nutrient retention, water holding capacity and soil structure
- has a carbon to nitrogen ratio like organic manures and composts which means there is a net release of nitrogen to the soil
Some residual liming benefit is available from lime treated sludges, but typically not enough to adjust soil pH. Lime treatment is designed to destroy pathogens in the sludge by raising pH and possibly temperature through chemical reaction at the time of treatment. It is also sometimes used to de-water the sludge.
Consider these risks. It can:
- result in a loss of nutrients to surface or groundwater if good spreading practices are not followed
- cause odour during storage and landspreading
- contain potentially toxic elements or other contaminants which may limit the application rate depending on the receiving soil
Potentially toxic elements and the limits that must be met are given in the Sewage sludge in agriculture: code of practice.
Operational considerations
Nitrogen availability in the sludge depends on the treatment process. Consider the type of sludge treatment:
- aerobically treated sludges release nitrogen over a prolonged period
- anaerobically treated sludges tend to be high in ammoniacal nitrogen which is readily available for plant uptake
Your application rate must reflect the nutrient requirement of the current or proposed crop for nitrogen and phosphate. You can use the fertiliser recommendations in RB209 and the requirements of other legislation such as the Nitrate Pollution Prevention Regulations.
Your receiving soil analysis must test for potentially toxic elements and other contaminants already present in the receiving soil as these may limit your application rate.
You must not landspread this waste on soils with a pH below 5.0. For soils with a pH of 5.0 to 5.2, an appropriate technical expert must justify the planned application.
This waste is controlled by the Sludge (Use in Agriculture) Regulations. See the Sewage sludge in agriculture: code of practice.
For further information see Guidelines for the application of sewage sludge to industrial crops.
Sewage sludge in forestry
If you plan to use sewage sludge in forestry, consider the:
- forest stand history – you can only incorporate waste before tree planting, or restocking
- slope – the greater the slope, the greater the risk of run-off
- groundwater – you must not apply sludge in a groundwater source protection zone 1 as required in your permit
- soil fertility and type – you can only apply the sludge to sites with very poor or poor soil nutrient classes, such as podzol soils, iron pan soils, littoral soils, disturbed and restored sites
- soil drainage characteristics and wetness – you must not apply to land when the water table is less than 1 metre from the surface or when the soil is saturated
- buffer strips – you must not apply close to water features
- sensitive receptors – you must not cause odour or noise nuisance near for example, dwellings and areas of recreation
Contact the Forestry Commission to spread this waste in forestry sensitive areas.
You must get advice from Historic England if you want to spread this waste on archaeological and heritage sites.
19 09 wastes are from the preparation of water intended for human consumption or water for industrial use.
19 09 02 Sludges from water clarification
You can use this waste if you hold:
- SR2010 No 4 – see table 2.2B
- SR2010 No 5 – see table 2.2
This waste stream includes 4 different types of sludge. These are:
- coagulant
- natural
- groundwater
- softening
You will need know the type of sludge and how it has been treated before you can spread this waste.
Coagulant sludges
These are sludges from raw water treatment, usually surface waters, with a coagulant. The coagulant is usually aluminium sulphate or ferric sulphate. They remove the following from the raw water:
- aluminium hydroxide flocs
- iron hydroxide flocs
- impurities such as colour and turbidity
Natural sludges
These can contain:
- schmutzdecke (‘dirt layer’) which is the impurities and biological layer formed on the surface of a slow sand filter – the raw waters pass through slow sand filters, usually without additional chemicals, to remove impurities
- biological material
- sands and grits
Groundwater sludges
These sludges come from dissolved metals oxidising, usually iron and manganese in groundwater. They can contain metal hydroxide or dioxide floc.
Softening sludges
These will contain calcium carbonate which are used for softening hard waters.
Benefits and risks
Consider these benefits. These sludges can contain:
- some nitrogen and potassium in bacterial cell debris form, mostly in natural sludges
- precipitated phosphate
- secondary plant nutrient sulphur
- trace elements such as iron, manganese, boron, fluoride, copper and zinc – these vary and you need to give evidence to claim benefit
- a large amount of organic matter if it comes from peat run-off in upland areas
- sands and fine grit which can improve the drainage of heavy soils and add body to medium and lighter soils
- calcium carbonate which could provide a liming benefit
Consider these risks:
- at low pH, calcium, magnesium and molybdenum are less available
- at low pH, aluminium, manganese, iron and zinc, become more available and may induce plant toxicity – it is rare to see toxicity across an entire field but areas within a field due to soil depth, type, drainage and pH may show symptoms
- phosphorus becomes less available at both extremes of pH, the optimum range for availability is between pH 6.0 and 7.0 – at low pH aluminium can lock up phosphate within the soil
- it can result in iron staining on crops
These sludges can result in high aluminium levels in soil. This can:
- damage roots
- result in foliage showing signs of toxicity – often compounded by phosphorus deficiency and soil acidity
- affect plant growth
- hold back cell division in roots
- reduce phosphorus transport from the roots to the shoots, resulting in a phosphorus deficiency
Operational considerations
The types and characteristics of the sludge from water clarification depend on the water treatment process and the quality of the raw water. You will also need to consider the geology of where you want to spread when you do your receiving soil analysis.
Under natural soil conditions most aluminium in the soil solution results from the pH dependant dissolution of aluminium containing minerals, such as gibbsite. Gibbsite is a low solubility product.
A rise in the concentration of aluminium species can cause risk to soil-dwelling organisms, surface water and can cause phosphorus lock-up. Risks are higher at low soil pH, where pathways might exist to surface water, and on soils with a low phosphorus index.
If you landspread sludges from raw water treatment using an aluminium sulphate coagulant, the source of aluminium added to the receiving soil is a mixture of aluminium sulphate and hydroxide. Sulphate ions can shift the equilibrium of aluminium in solution towards increased soluble aluminium concentrations.
You will need to analyse water clarification sludges for major and trace element total contents. As a minimum these need to include aluminium, iron, manganese, sulphate, and fluoride. This is to understand how those elements can be extracted using appropriate leachate tests. You must use these data to assess the potential nutrient benefits of the sludge application.
Precautionary measures
Applying this type of waste sludge can cause risks after it has been spread. These include:
- the potential for aluminium release
- that mobile aluminium can stunt root growth and result in induced phosphate deficiency in crops
- trace element imbalance in livestock and plants
Use these precautionary measures to reduce potential adverse effects from this waste. If you do not use these measures you must justify why you have not.
Although aluminium is a major component of soils, it becomes mobile in the soil at pH 5.5. As a precaution you:
- can apply sludge from aluminium water treatment to soils of pH 6.0 and above
- maintain the pH of the amended soil
You can:
- use sludges that have been aged for greater than 6 months to reduce potential impacts from metal leachates
- avoid excess build-up from aluminium and iron levels in the surface layer of pasture grass by not doing repeated applications – this avoids possible effects on ruminant animals when they directly ingest the sludge
If you do not use these measures, you must justify why your waste application is beneficial and not detrimental to the soil, crop, animal health, fauna or watercourse, where applicable.
19 12 wastes are from the mechanical treatment of waste (for example sorting, crushing, compacting, pelletising) not otherwise specified.
19 12 12 Recycled gypsum from plasterboard
You can use this waste if you hold:
- SR2010 No 4 – see table 2.2B
- SR2010 No 5 – see table 2.2
You may be able to operate under Storing and spreading gypsum waste to benefit land: LRWP 59.
If you cannot keep to the limits specified and meet all the requirements of the low risk waste position, you will need to apply for a landspreading permit.
You can use the waste produced from manufacturing and treating waste plasterboard to get gypsum. Plasterboard is mostly made up of gypsum. However, waste plasterboard is not waste gypsum because it contains other materials. Gypsum from reprocessing waste plasterboard may contain:
- organic and inorganic binders, fillers, fibre strands and backing materials
- additives such as flame retardants
The waste producer must remove the binding and backing materials.
Gypsum
You can use gypsum (calcium sulphate) to restore or improve soil that:
- is sodic
- has been flooded with sea water
- is non-calcareous clay (some types)
Gypsum involves cation exchange reactions where calcium cations replace sodium cations in the layers of clay particles in the soil. Gypsum may cause the exchange of other cations, such as magnesium.
Cation exchange is one of the most common and important soil reactions. It takes place on the negatively-charged surfaces of soil particles.
You can use the capacity of the soil to exchange cations (known as the ‘cation exchange capacity’) to work out the appropriate application rate. You will need to know the:
- sulphur requirement of the soil
- cation exchange capacity
You can use the method in: BS 3882: Specification for topsoil. Annex D (normative), Extraction of exchange cations in soil – you will have to pay for this.
You can use gypsum to:
- condition soil
- fertilise soil
Condition soil
You can use gypsum to condition clay soils with high sodium and magnesium concentrations that tend to slump. For example, saline and sodic soils affected by flooding from sea water. The calcium in the gypsum as calcium sulphate replaces the sodium and magnesium in the soil, enabling the calcium to flocculate the soil. This creates more pore space and adds crumb structure to the soil.
Fertilise soil
Gypsum contains large quantities of sulphur. You can use gypsum to fertilise soil by supplying the sulphur needs of growing crops.
Your application rates will depend on the benefit you are claiming. Application rates to fertilise soil are typically lower than those used to condition soil.
With less deposits of sulphur from the atmosphere, many agricultural soils and crops may now benefit from adding sulphur. Use of manufactured fertilisers containing sulphur is increasing.
Sometimes, applying gypsum has produced unexpected improvements in crop yields. This has been put down to a correction of sulphur deficiency that had not been diagnosed.
Benefits and risks
Consider these benefits. It can be used:
- to restore the soil structure of saline and sodic soils, especially those affected by flooding from sea water
- for some types of non-calcareous and poorly structured clay soils over time to improve the structure of the soil
- to provide a source of calcium and sulphur – gypsum can contain up to 20% sulphur, depending on the purity of the waste
Consider these risks. It can contain:
- contaminants originating from the quarried or flue gas gypsum such as metals and fluoride
- contaminants that come from the plasterboard manufacturing process
- binding agents such as fire retardants
- backing materials, such as paper, foils or card
Application rates
If you plan to apply this waste as a soil conditioner to arable land, you can use typical rates of 5,000 to 6,000kg/ha gypsum and incorporate it into the upper 25cm of soil.
For crops with a sulphur deficiency, you can apply gypsum at 47 to 143kg/ha (25 to 75kg/ha sulphuric trioxide) based on sulphur deficiency alone. Your application rate will also depend on soil type.
If you are claiming benefit as a fertiliser, you will need to consider that not all the sulphate in the gypsum will be in a soluble (crop available) form. Your gypsum application rate will need to match the supply of available sulphur to the crop need.
There is little if any benefit from applying gypsum to very light soils, such as sands and loamy sands to give them structure.
See RB209 for guidance on sulphur inputs relative to soil type, crop and soil index.
Find more information in Recycled gypsum from waste plasterboard: quality protocol.
You must also follow the guidance on how to manage organic manures in Landspreading: how to manage soil health.
19 12 12 Soil substitutes other than that containing dangerous substances only
You can use this waste if you hold SR2010 No 5 – see table 2.3.
Using soil substitutes or conditioners and improvers
If you propose using a soil substitute or soil conditioner or improver you must know how they differ. A:
- soil substitute is a material used to create a soil profile where one does not exist
- soil conditioner or improver is used to improve an existing soil profile
You can use waste code 19 12 12 Soil substitutes other than that containing dangerous substances only as a soil substitute. You can use it for ecological improvement in land restoration and reclamation schemes under SR2010 No 5 or a similar bespoke permit. For example, in landfill restoration schemes to create a vegetated area where there is no existing soil profile. You must be able to demonstrate ecological improvement. For landfill restoration schemes you must follow Restore your landfill site.
Where a soil profile already exists, you must not use 19 12 12. You can use the other types of waste listed in your permit as a soil conditioner or improver.
The Environment Agency accept that to create a soil substitute, you may need to blend wastes with other imported soil substitutes. You must create the resultant soil to an appropriate standard, usually the British Standard specification for topsoil. The soil must also meet the requirements for potentially toxic elements (PTEs) as given in the Sewage sludge in agriculture: code of practice.
To produce soil substitutes, you must hold an appropriate permit such as SR2010 No 12: treatment of waste to produce soil, soil substitutes and aggregate. The soil substitute must not include:
- hazardous waste or dangerous substances
- contaminants such as asbestos fragments, plastics, glass, metals, treated timber, foils and films
Benefits and risks
The main benefit this waste gives is to create a new soil profile for ecological improvement. For example, you can use a soil substitute to create a planted area on a landfill site as part of a restoration programme.
It can also:
- improve structure and drainage in heavy soil by adding grits and sands
- replace soils lost by erosion
- add organic matter to the soil which is beneficial to soil structure
It can be used to improve soil bulk density which gives benefit by:
- improving drainage through large pore spaces
- increasing water retention in smaller pore spaces
- making the soil easier to work with
- improving how deep roots grow
- improving nutrient mobility
These improvements may only be temporary. For example, creating cultivations and seed beds decreases bulk density and breaks up any compacted soil layers. However, it can re-compact if the soil is disturbed by traffic from machinery, rainfall and other activities.
Adding organic matter can improve soil bulk density for longer.
Consider these risks. Applying this waste can:
- contaminate the soil with chemicals, for example metals from treated products
- potentially contaminate the soil with plant diseases
- cause dust nuisance from site activities and during landspreading
- contaminate the soil, for example with plastics and glass
- cause nitrogen lock-up if high carbon to nitrogen ratio material is spread, such as shredded wood and sawdust
You must also follow the guidance in Landspreading: how to manage soil health for how to manage:
- organic manures
- contaminants
- pests and diseases
- carbon to nitrogen ratio of the soil
- slow release nutrients in restoration schemes
Consider that improving soil bulk density can:
- increase soil erosion by surface water
- cause soil loss by wind erosion, due to rapid surface drying
- increase oxidation of organic matter
Operational considerations
Potentially toxic elements and other contaminants present in the soil substitute must not exceed the receiving soil limits specified in the Sewage sludge in agriculture: code of practice.
If you plan to use ripping, chisel plough or other deep incorporation cultivation practices, then you will need to consider:
- previous land use
- buried obstacles such as carcass burial pits, drains and services such as pipelines
You can use the information given in the Code of practice for the sustainable use of soils on construction sites, although it is aimed at the construction industry.
You can also use BS 3882: Specification for topsoil. You will need to pay for this.
19 13 wastes are from soil and groundwater remediation.
19 13 04 Sludges from soil remediation other than those mentioned in 19 13 03*
You can use this waste if you hold SR2010 No 5 – see table 2.3.
You must not use 19 13 03* Sludges from soil remediation containing hazardous substances.
In your benefit statement you will need to:
- give detailed information on the substances likely to be present in this waste
- methods and purpose of the remediation