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Prevention of Environmental Pollution from Agricultural Activity

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Prevention of Environmental Pollution from Agricultural Activity

5 NON-AGRICULTURAL WASTES AND OTHER IMPORTED

ORGANIC WASTES

This section is primarily relevant for producers of non-agricultural waste, and contractors. It has been updated to reflect recent changes in legislation (e.g. on Animal By-Products and on Waste Management Licensing). The Scottish Executive is considering revising the 1989 Sludge (Use in Agriculture) Regulations, so that the safeguards provided by the "Safe Sludge Matrix" are given statutory force.

DOs

**1. Comply with the Sludge (Use in Agriculture) Regulations 1989 (as amended) by:

  • Analysing sludge and soil prior to spreading.

  • Avoiding applying sewage sludge to soils with a pH of less than 5.0.

  • Following all mandatory stock grazing, cropping and harvesting restrictions.

**2. Comply with the Waste Management Licensing Regulations 1994, as amended, by:

  • Proving to SEPA that land treatment activities benefit agriculture or improve ecology.

  • Providing supporting information to SEPA .

  • Keeping appropriate records for 2 years.

**3. Ensure that non-agricultural waste is stored:

  • At a distance more than 10m from any inland or coastal water.

  • 50m from any well, borehole etc for the purpose of any water supply (except domestic water supply).

  • 250m from any well, borehole or other source of domestic water supply.

**4. Treat blood, or mixtures of blood and gut contents, before spreading on agricultural land:

**5. Pre-notify SEPA of the start and finish dates of spreading. Annual renewal of registration required.

**6. Note that SEPA charge a fee to facilitate site inspections and assessment of registration notifications.

**7. Note that SEPA can refuse to register/remove from the register an exemption under certain circumstances, provided reasons are given.

**8. Keep records of any operations carried out on farm for period of two years (and make them available to SEPA).

**9. Assess the risk of pollution and land suitability for the application of non-agricultural wastes to land.

**10. Prevent direct and indirect entry of the waste into drains, especially with soil injection into fields with gravel backfilled drains.

**11. Ensure that wastes stored while waiting to be applied to land, and wastes being applied to land, do not cause a nuisance (e.g. obnoxious smells).

12. Check with the Safe Sludge Matrix (an agreement between the UK water industry and the British Retail Consortium on sludge use), your farm quality assurance schemes and your produce buyer before using non-agricultural wastes. Use of such material may have commercial consequences for acceptability of produce to retailers and processors.

13. Follow the guidance that exists in the Code of Practice for Agricultural Use of Sewage Sludge and the Code of Practice for the Management of Agricultural and Horticultural Waste.

14. Account for non-agricultural waste when implementing a Manure Management Plan (Farm Waste Management Plan) and check on how safely the waste can be used in your farm system.

15. Establish and agree what responsibilities and measures the waste provider or contractor will need to take to avoid pollution and odour nuisance.

16. Leave an untreated strip a minimum of 10m wide beside all watercourses and at least 50m from any spring, well or borehole.

17. Avoid the risk of surface run-off. Consider contour injection where there is a risk of injected wastes running out of the injection slots on sloping land.

18. Prepare and implement a nutrient plan for the land treated and reduce inorganic fertiliser use by allowing for the available nutrients in the waste.

19.Seek professional advice if in doubt about how to manage imported wastes on your farm.

20. Spread non-agricultural wastes only when field and weather conditions are suitable, to prevent soil and water pollution.

DON'Ts

**1. Don't store non-agricultural wastes unless such storage is secure and conforms to legal requirements.

**2. Don't permit any non-agricultural wastes to be applied without first knowing the analysis, as required by the WMLR 1994, as amended.

**3. Don't employ any waste contractor or company involved in spreading wastes unless you are satisfied they are competent and fully trained.

**4. Don't spread gut contents or mixtures of blood and gut contents from abattoirs on pastureland.

5. Don't spread liquid sewage sludge and other liquid organic wastes:

  • within 10m of a watercourse or 50m of a drinking water supply;

  • to steeply sloping fields, when the soil is wet or waterlogged, when there is a flooding risk or when heavy rainfall is forecast;

  • when the soil has been frozen for 12 hours or longer in the preceding 24 hours or is covered in snow;

  • at a rate that fails to account for the overall suitability of the land. In any case, the rate should never exceed 50m 3/ha for surface spreading;

  • when fields have been pipe or mole drained, or subsoiled over existing drains within the last 12 months.

  • to land which has been poached or compacted.

6. Don't apply wastes at nutrient application rates greater than crop rotation requirements.

7. Don't apply raw or untreated sewage sludge on land for food production.

8. Don't encourage the spreading of non-agricultural wastes on your land outwith daylight hours.

9. Don't apply imported wastes to any statutory conservation sites (e.g. SSSIs or NNRs) or other areas with a conservation, archaeological or historic value without prior notification to Scottish Natural Heritage (SNH).

Introduction

5.1 The main non-agricultural organic wastes applied to agricultural land arise from sewage treatment, paper mills, compost producers, creameries, distilleries and food processors. Although many of these wastes potentially have valuable fertilising and soil conditioning properties, their application under unsuitable conditions or at inappropriate rates can give rise to pollution and contamination of soil, water or air.

5.2 This section recommends management practices for waste producers, contractors and farmers so as to avoid or minimise the risk of pollution, while enabling sustainable agricultural practices to continue. Application to agricultural land should be carried out as a method of beneficially recycling nutrients to the soil and not as a cheap method of waste disposal. Several serious pollution incidents occur each year due to inadequate precautions being taken when spreading non-agricultural waste to land. Contractors carrying out spreading activities on farm should be suitably trained, qualified and competent to carry out the operation for which they are employed. Farmers and contractors should be aware of legal requirements and willing to follow the guidance in this Code.

5.3 All applications of imported wastes spread on farmland should be included in the calculations within the Manure Management Plan (Farm Waste Management Plan). This is mandatory for Fertiliser and Manure Plans in Nitrate Vulnerable Zones (NVZs).

What legislation must be complied with?

5.4 There are several pieces of legislation relating to the spreading of non-agricultural waste on land, and any resulting discharge to surface water and groundwater. These are reviewed later in this section. The Waste Management Licensing Regulations (WMLR) 1994 (as amended) allow certain non-agricultural wastes to be applied to agricultural land. The operations do not need a waste management licence, but are controlled under exemptions registered with SEPA. Waste spreading operations must be carried out in a way that does not endanger human health or harm the environment. The non-agricultural wastes to which this exemption from licensing applies are given in Appendix 4. The WMLR include requirements for record keeping, risk assessment, a certificate from a technically competent person describing the agricultural benefit or ecological improvement expected, and waste analysis in relation to application for registration of an exemption. Any non-agricultural wastes not listed in Appendix 4 would require a waste management licence in respect of spreading to land.

Maximum application rates

5.5 The exemption from licensing depends upon not more than 250 tonnes/ha/yr of any of the specified wastes being spread in any 12-month period. Where more than one type is applied, the quantities must be combined within this tonnage limit. In the case of dredgings from inland waters only, a higher limit of 5,000 tonnes/ha/yr applies. These limits are maximum ceilings. On most land, and for most wastes, the annual application rates will need to be considerably lower than this. The exemption only applies where the spreading or associated storage of the waste results in a benefit to agriculture or ecological improvement.

Pre-notification requirements and transport of wastes

5.6 Only registered waste carriers can transport the waste to agricultural land. The contractor or farmer must provide full details to SEPA before spreading can take place. Transporters of non-agricultural waste must be registered with SEPA as a registered waste carrier. Farmers are, however, able to transport their own wastes without registration.

5.7 Forms to register exemptions and guidance are available from local SEPA offices.

Storage

5.8 The exemption from licensing has been extended to include the temporary storage of not more than 1250 tonnes of non-agricultural wastes on the farm where they are to be spread. All storage must be on land intended to be used for spreading. Waste should be stored in a secure container or lagoon on the farm where it is to be spread. Stores should not be filled to more than 90% capacity. They should not be sited within 10m of any inland or coastal waters, or within 50m of a well or borehole that supplies water for non-domestic use, or 250m from any well, borehole or other source used for a domestic water supply. The site should be fenced to exclude livestock and should be located a suitable distance away from houses. It is a statutory requirement under the WMLR that wastes stored while waiting to be applied to land (and waste being applied to land) do not cause a nuisance such as obnoxious smells.

Vegetable wastes

5.9 There is a risk of introducing pests and diseases, such as potato brown rot, potato ring rot and potato cyst nematode, through the spreading of waste derived from imported agricultural or horticultural produce to arable land. The Plant Health (Great Britain) Order 1993 and The Potatoes Originating in Egypt (Scotland) Regulations 2001 include statutory controls on waste from certain imported products which may pose a risk to domestic plant health. Guidance on methods to minimise plant health risks by the management of waste from the commercial handling of certain types of plant produce is provided in the Code of Practice for the Management of Agricultural and Horticultural Waste.

Animal processing wastes

5.10 Under the TSE (Scotland) Regulations 2002, it is an offence for any protein derived from specified risk material to be moved without a licence. These regulations also ban the use of fertilisers containing mammalian meat and bone meal. The Animal By-Products (Scotland) Regulations 2003 prohibit livestock from gaining access to unprocessed waste food which contains or has been in contact with animal by-products (including blood). The Regulations also prohibit the land-spreading of unprocessed abattoir waste, including blood.

Sewage sludge

5.11 Use of sewage sludge on farmland is controlled by the Sludge (Use in Agriculture) Regulations 1989 (as amended), also known as "The Sludge Regulations", which control the build-up of Potentially Toxic Elements (PTEs) in soil and restrict the planting, grazing and harvesting of certain crops following the application of sludge. The statutory controls on the application of sewage sludge to agricultural land must be complied with in order to be eligible for the Single Farm Payment. Sludge producers (in Scotland this generally means Scottish Water or their contractors) are required to analyse field soils and sludges prior to application and to maintain detailed records of applications of all sludge to farmland. Further guidance and requirements are given in the UK-wide Code of Practice for Agricultural Use of Sewage Sludge (amended 1996 and due to be amended again soon) and also in "The Safe Sludge Matrix 2001" (an agreement between the UK water industry and the British Retail Consortium on sludge use). Further information is given in Appendix 3 to this section.

5.12 Responsibility rests with the producer for compliance with The Sludge Regulations in regard to the analytical testing of the sludge. Farmers should not allow spreading without this having been done.

5.13 In addition, the UK Code of Practice recommends limits for molybdenum, selenium, arsenic, and fluoride. These limits have been set to take into account possible toxic effects on plants and animals and toxicity to the food chain and on soil processes. The UK Code of Practice also provides recommendations for the maximum concentration of contaminants in soils under grass which should be sampled to a depth of 7.5cm.

Composting

5.14 The WML Amendment Regulations 2004 detail the types and quantities of wastes that can be composted on farm under an exemption. It is possible to chip, shred and compost a wide range of biodegradable materials, providing that the total quantity of waste stored and treated(including maturation) does not exceed 400 tonnes. The storage of raw materials is permitted at a site where the composting does not take place, but this must not exceed 10 tonnes at any time and storage is limited to a maximum of 48 hours.

Water pollution

5.15 Farmers and contractors who neglect their duty to prevent pollution of waters (e.g. as a result of run-off) may be liable to enforcement action.

General

5.16 Establish and agree what responsibilities and measures the waste provider or contractor will need to take to avoid pollution, odour and other statutory nuisances. Regulations made under the Environmental Protection Act 1990 confer a Duty of Care upon producers, carriers and disposers of waste to ensure that:

  • waste is not kept, treated or disposed of illegally;

  • an adequate written description of waste accompanies the transfer of waste;

  • the waste is held securely and does not escape; and.

  • the waste is only passed to persons authorised to receive it.

If you are unclear about any of the requirements, contact your local SEPA office.

DETERMINING THE SUITABILITY OF WASTES FOR LAND APPLICATION

Manure Management Plan (also known as a Farm Waste Management Plan)

5.17 Every livestock farm should draw up a Manure Management Plan (also known as a Farm Waste Management Plan) to establish the quantities of animal manures produced and the available nutrient content. This should be used to demonstrate that the application of inorganic fertilisers, livestock manures and slurries and non-agricultural wastes matches the nutrient requirements of the rotation and crops being grown. Before agreeing to accept non-agriculturally derived organic wastes, a farmer must carefully assess whether these additional nutrient inputs can be utilised effectively to give a "benefit to agriculture or ecological improvement" without causing a pollution threat.

5.18 All applications of waste materials to soils should be in quantities and at frequencies which convey positive benefits without causing pollution. Factors to take into consideration are the type and category of wastes, land and crop. Properly qualified advice should be sought on what application rate is appropriate for each waste material, each soil and each site. The WMLR Amendments 2003 now specifically require submission of a certificate describing how the treatment will result in benefit to agriculture or ecological improvement prepared by or based on advice from a person with appropriate technical or professional expertise. The WMLR 2004 restricts to 50 hectares the area of land on a farm that can be treated by non-agricultural wastes (excluding sewage sludges) under a single exemption.

Fertilising

5.19 Those farming within an NVZ should be aware that non-agricultural waste used as an organic material will contribute to the overall N from organic sources applied to the land. There are mandatory measures in NVZs to control the application of nitrogen, which must be followed by all farmers as a Cross Compliance requirement. Wastes which contain significant quantities of nutrients may have valuable fertilising properties. The rate and timing of application of waste must be matched to the nutrient requirements of the crop. If this is exceeded then the operation will be classed as waste disposal rather than fertilisation. To be of fertiliser value, at least part of the nutrient content should be available or become available for plant uptake within 3 years. Some non-agricultural wastes contain other important nutrients (e.g. sulphur and magnesium) or a range of trace elements. If however a trace element deficiency has been diagnosed, it is important to apply a specific treatment because the trace element content of most non-agricultural wastes is generally insufficient to correct a deficiency.

5.20 The Fertiliser Series Technical Notes, produced by SAC, provide detailed information on the nutrient requirements of crops and grass, as well as the fertilising value of different types of manures and slurries and inorganic fertilisers.

5.21 Chemical analyses of the waste usually measure the total quantities of nutrients. However, the effectiveness or availability of these nutrients for crop uptake must be assessed before the fertiliser value of the imported waste can be calculated. Certain wastes with a high C: N ratio may not initially release any of its nitrogen for plant uptake as a result of a temporary locking-up of plant available N (immobilisation).

Liming value and pH

5.22 Wastes such as lime sludge can have a high liming (neutralising) value which makes the waste a useful liming material for acid soils. Care must be taken however to avoid raising the soil pH too high through excessive applications as this may lock-up some trace elements. The Regulations prohibit the spreading of sewage sludge on soils with a pH less than 5.0.

Soil conditioning

5.23 Certain non-agricultural wastes can act as a soil conditioner and may also add useful amounts of organic matter to the soil which may improve soil structure and increase the water holding capacity. However such improvements to soil conditions will only be significant if regular and well managed dressings of bulky and highly organic wastes are made to a low organic matter soil. Cross Compliance/GAEC requires that soil organic matter levels are maintained through appropriate practices, including optimising the use of organic manures by basing rates of application on soil and crop needs.

HAZARDS

5.24 The amount of PTEs, organic contaminants and pathogens, and environmental risks of any particular waste type can vary greatly from one waste producer to another. There can also be great variability in the analysis on a monthly basis for any particular waste producer. Farmers should seek up-to-date and representative analysis from the waste producer (or waste contractor) and seek agronomic and environmental advice. It is important that accurate records of the type of waste and rate of application are kept for each field.

5.25 Check with "The Safe Sludge Matrix", your farm quality assurance schemes and your produce buyer before using non-agricultural wastes, as there may be commercial consequences in acceptability.

Potentially Toxic Elements (PTEs)

5.26 Certain wastes such as those from sewage works, distilleries, textile plants and paper mills can have high levels of metals and must be used with caution. It is strongly recommended that application of non-agricultural wastes should be made at a rate which does not exceed the levels specified for heavy metal loadings as given in The Sludge Regulations (see Appendix 1 to this Section). Particular care should be taken with dredgings from urban rivers, as these may contain high levels of toxic metals, oils and other PTE's.

Pathogens

5.27 Some non-agricultural wastes can contain high levels of pathogens and it is essential that this be assessed before application. It is recommended that these wastes are not used on farmland unless it can be clearly demonstrated that there is minimal risk of pathogen transmission. The WMLR 2003 and the Animal By-Products (Scotland) Regulations 2003 require that blood or a mixture of blood and gut contents be treated in accordance with the EC Animal By-Products Regulation 1774/2002 before spreading to agricultural land.

Organic contaminants

5.28 Wastes from some industrial processes may contain significant quantities of other potentially toxic organic substances, antibiotics or residual pesticides and must not be applied to agricultural land. It is, therefore, essential that full details of the source of the waste is assessed and a comprehensive analysis is carried out to determine if application to land is safe.

Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD)

5.29 Wastes with a high BOD or COD will be highly polluting if allowed to enter a watercourse by seepage or run-off. Application of such wastes can also result in a temporary soil oxygen depletion leading to poor plant growth. The WMLR 2003 require details of waste BOD and COD before a land treatment exemption can be registered.

Acidity and salinity

5.30 The application of wastes which have a high level of salinity or acidity can result in damage to soils and crops as well as causing water pollution.

RECOMMENDED APPLICATION CRITERIA

5.31 There are a number of factors to be taken into consideration before, during and after the application of any non-agricultural wastes.

Assess land suitability

5.32 The land suitability for the application of non-agricultural wastes follows the same criteria as for farmyard manures and slurries. These are determined by field factors and proximity to watercourses, soil type and weather conditions. Discourage the spreading of non-agricultural wastes on farmland outwith daylight hours. You will be helping to protect the environment by ensuring better supervision and control of field operations if you adopt this policy and any off-site impacts such as pollution of local watercourses will not go unnoticed.

Assess the soil capability/fertility

5.33 Having identified suitable sites for application of non-agricultural wastes, the next step is to obtain an analysis to determine the current status of the soil in terms of pH, nitrogen, phosphorus, potassium, magnesium and PTE content. PTEs may include copper, zinc, cadmium, chromium, lead, mercury, nickel and any others appropriate to the source of the waste. The nutrient requirement of the growing crop should then be calculated taking into account the soil nutrient status and nutrient residues from previous cropping and manurial practice.

5.34 The WMLR 2003 restrict the total nitrogen applications from wastes to 250kg/hectare in any 12-month period.

Analyse the waste

5.35 The waste should be first analysed for nitrogen, ammonium-nitrogen, phosphorus and potassium, BOD, COD, pH, dry solids and salinity. The waste may also require (under the WMLR 2003) analysis of PTEs, oils and fats, prescribed substances, C:N ratios, pathogens and neutralising value (analysis depending on waste type and possible hazards).

A bioassay (a controlled plant growth experiment) or similar trial should ideally be obtained from the contractor to determine the effects of the waste on plant growth. If these tests are shown to be satisfactory, land application can be considered.

Assess the application rate

5.36 Using the waste analysis, the application rate can be calculated to match the nutrient requirements of the crop and/or the maximum acceptable application of PTEs (whichever is lower).

5.37 In all cases, application rates should not exceed the nutrient requirements of the crop or rotation. Surface applications of liquid wastes should not exceed 50 m 3/ha at any single dressing. Solid wastes or injected wastes may be applied at higher rates provided there is no risk of pollution and crop nutrient requirements are not exceeded (whichever is lowest).

5.38 There are other mandatory requirements if the holding is in an NVZ. See Section 6 for further details.

Assess the application method

5.39 Some soil types are suitable for injection of non-farm liquid wastes. Injection of liquid non-farm wastes directly into soil not only eliminates smell and unsightliness of surface application but also prevents surface run-off, crop taint and transfer of pathogens in pasture. In addition, soil injection loosens the soil, reduces losses of ammonia and allows application to land near housing. Use of an umbilical system and low ground pressure tyres will reduce wheelslip and soil compaction during injection. When soil conditions are suitable and the operation is correctly carried out, soil injection is a very suitable technique for liquid waste application. However, great care is required where field drainage has been installed, especially if it has gravel backfill, since wastes may run through into the drains themselves or the drains may become damaged by equipment. The WMLR Amendments 2003 require that a risk assessment of pollution be carried out and submitted to SEPA before an exemption can be registered by SEPA. Such a risk assessment would need to consider the effects of field drains on pollution. Injection into recently drained, moled or subsoiled soils can result in water pollution as liquid waste moves rapidly from soil cracks into field drains and into watercourses.

5.40 Poorly managed injection can result in several other problems. Anaerobic conditions can form in the injection cavity if too high a sludge rate is applied, particularly if the soil becomes waterlogged. Injection into sloping fields can result in seepage of liquid waste from the injection cavity onto the surface at the base of the slope. Variable yields in crops can be caused by non-uniform distribution of wastes.

5.41 When grassland is very dry, injection can cause excessive surface disturbance and crop root damage leading to dieback. Rolling as soon as the land is trafficable will help minimise the problem and will settle any residual soil uplift. If the injection of untreated organic wastes is not carried out correctly, the normal three-week interval before animals are allowed to graze will need to be substantially increased to protect their health.

5.42 Adequate precautions must be taken during spreading to protect the health and safety of the operator.

Post-application measures

5.43 Care is always required to ensure that spreading does not result in ponding, run-off or seepage into field drainage systems. Watercourses which could be reached by waste run-off should be inspected at least daily following spreading and, if pollution is found, SEPA should be notified and immediate action taken to terminate the discharge. After the application of any non-agricultural waste, the planting, grazing and harvesting requirements given in The Sludge Regulations should be followed to minimise any pathogen risks.

SEWAGE SLUDGE

5.44 To minimise the risk to human and animal health and damage to plants, sludge applications should be co-ordinated with planting, grazing and harvesting operations. Constraints which must be taken into account are set out in Appendices 1 and 2 to this Section.

5.45 The Safe Sludge Matrix should also be followed (see Appendix 3). The Matrix does not allow raw or untreated sewage sludge to be used on agricultural land for food production. Undigested sludge or septic tank sludge should therefore not be used on land used for food crops.

ANIMAL PROCESSING WASTES

5.46 The WMLR 2003 and the Animal By-Products (Scotland) Regulations 2003 now require that blood, and blood and gut contents from abattoirs under WMLR 2003, be treated prior to land application to minimise pathogen content and also to reduce pollution risks. The treatment processes should be designed to ensure that at least 99% of pathogens have been destroyed.

5.47 Blood or blood and gut contents when mixed have an extremely high BOD, and will be highly polluting if they should inadvertently enter a watercourse by seepage or run-off, and could result in a temporary soil oxygen depletion leading to poor plant growth. Treated blood should be soil injected at rates not exceeding the nitrogen requirement of the crop. To keep within the mandatory limit of 250 kg/ha per annum of attributable nitrogen to land from the use of the waste, the annual application should not exceed 14m 3/ha of undiluted(treated) blood. Great care is always required to ensure that spreading does not result in ponding, run-off or seepage into field drainage systems. Do not inject treated blood and gut contents when the soil is wet or waterlogged or when heavy rain is forecast. Applications should be carried out in accordance with the principles set out in Section 4.

5.48 The following precautions should be undertaken when spreading:

  • the material should be injected, not surface applied;

  • do not apply treated blood and gut contents to grasslan;

  • never apply treated blood and gut contents to fields which grow ground crops for human consumption or crops which may be eaten raw by humans and animals.

Appendix 1

Sludge (Use in Agriculture) Regulations 1989, as amended: Maximum permissible concentrations of potentially toxic elements (PTEs) in soil (0-25 cm) 1 after application of sewage sludge waste and maximum annual rates of addition

Potentially Toxic Element (PTE)

Maximum permissible concentration of PTE in soil (mg/kg dry solids)

Maximum permissible average annual rate of PTE addition over a 10 year period (kg/ha)

pH 3

pH

pH

pH

5.0-5.5

5.5-6.0

6.0-7.0

>7.0

Zinc (Zn)

200*

250*

300*

450*

15

Copper (Cu)

80 (130)

100 (70)

135 (225)

200

7.5

Nickel (Ni)

50 (80)

60 (100)

75 (125)

100

3

for pH 5.0 and above

Cadmium (Cd)

3

0.15

Lead (Pb)

300

15

Mercury (Hg)

1 (1.5)

0.1

Chromium 2 (Cr)

400 (600)

15

Molybdenum 2 (Mo)

4

0.2

Selenium 2 (Se)

3 (5)

0.15

Arsenic 2 (As)

50

0.7

Fluoride 2 (F)

500

20

Footnotes

1. The maximum permissible concentration for grassland soils sampled to a depth of 7.5cm is the same except where given in brackets.
2. These are recommended, not regulatory limits.
3. Application of sludge to soils with a pH less than 5.0 is prohibited.
* The UK Code of Practice for Agricultural Use of Sewage Sludge (amended 1996) set precautionary limits of 200 mg/kg for Zn (300 mg/kg pH>7.0) and this has been accepted by the water industry and is recommended.

Appendix 2

Sludge (Use in Agriculture) Regulations: acceptable uses of treated sludge in agriculture and horticulture (see also the Safe Sludge Matrix)

When applied to growing crops

When applied before planting crops

Cereals, oilseed rape

Cereals, grass, fodder, sugar beet, oilseed rape, etc.

Grass 1

Fruit trees

Turf 2

Soft fruit 3

Fruit trees 3

Vegetables 4

Potatoes 4,5

Nursery stock 6

1 No grazing or harvesting within 3 weeks of application.
2 Not to be applied within 3 months before harvest.
3 Not to be applied within 10 months before harvest.
4 Not to be applied within 10 months before harvest if crops are normally in direct contact with soil and may be eaten raw.
5 Not to be applied to land used, or to be used, for a cropping rotation that includes seed potatoes or seed potatoes for export.
6 Not to be applied to land used or to be used for a cropping rotation that includes basic nursery stock or nursery stock (including bulbs) for export.

Appendix 3

Safe Sludge Matrix

1. CROP GROUP

UNTREATED SLUDGES

CONVENTIONALLY TREATED SLUDGES

ENHANCED TREATED SLUDGES

FRUIT

8

8

4

bracket

10 month harvest interval applies

SALADS

8

8
(30 month harvest interval applies)

4

VEGETABLES

8

8
(12 month harvest interval applies)

4

HORTICULTURE

8

8

4

COMBINABLE
& ANIMAL FEED
CROPS

8

4

4

- GRAZED

8

(Deep injected or ploughed down only)

8

bracket

3 week no grazing and harvest interval applies

4

bracket

3 week no grazing and harvest interval applies

GRASS & FORAGE

- HARVESTED

8

(No grazing in season of application)

4

4

4 All applications must comply with "The Sludge Regulations" and UK Code of Practice for Agricultural Use of Sewage Sludge (to be revised).

8 Applications not allowed (except where stated conditions apply)

NOTE:

  • Conventionally treated sludge has been subjected to defined treatment processes and standards which ensure that at least 99% of pathogens have been destroyed.

  • Enhanced treated sludge will be free from Salmonella and will have been treated so as to ensure that 99.9999% of pathogens have been destroyed (a 6 log reduction).

Appendix 4

Waste which can be used for agriculture where such treatment results in benefit to agriculture or ecological improvement in compliance with the Waste Management Licensing Regulations 1994 (as amended):-

Wastes from agriculture, horticulture, aquaculture, forestry, hunting and fishing

  • Plant tissue waste

  • Straw, wood or paper-based bedding waste, slurry or dirty water from stables, zoos, animal parks or livestock markets, animal faeces, urine and manure.

Wastes from sugar processing

  • Soil from cleaning and washing beet

Wastes from wood processing and the production of panels and furniture

  • Waste bark and cork

  • Sawdust shavings, cuttings, wood, particle board.

Wastes from pulp, paper and cardboard production and processing

  • Waste bark and wood, including virgin pulp.

  • Lime mud waste

  • Sludges from on-site effluent treatment plants treating only virgin paper wastes which contain no inks.

  • De-inked paper sludge from paper recycling, paper crumble derived from virgin pulp which contains no inks.

Soil (including excavated soil from contaminated sites), stones and dredging spoil

  • Soil and stones.

  • Dredging spoil

Wastes from aerobic treatment of solid wastes

  • Off-specification compost consisting only of biodegradable waste

Garden and park wastes(including cemetery wastes)

  • Biodegradable waste

  • Soils and stones

Wastes from the preparation and processing of meat, fish and other foods of animal origin

  • Materials unsuitable for consumption or processing consisting of blood and gut contents from abattoirs or poultry preparation plants only if treated in accordance with EC Regulation No 1774/2002 of the European Parliament and of the Council of 3 October 2002 laying down health rules concerning animal by-products not intended for human consumption.

  • Wastes from fruit, vegetables, cereals, edible oils, cocoa, coffee, tea and tobacco preparation and processing; conserve production; yeast and yeast extract production, molasses preparation and fermentation

  • Wastes from sugar processing

  • Wastes from production of dairy products

  • Wastes from the baking and confectionery industry

  • Wastes from the production of alcoholic and non-alcoholic beverages(except coffee, tea and cocoa).

Wastes from the leather and fur industry

  • Sludges, in particular from on-site effluent treatment free of chromium

Wastes from the textile industry

  • Organic matter from natural products (for example, grease, wax)

  • Wastes from finishing other than those containing organic solvents

  • Sludges from on-site effluent treatment

  • Wastes from unprocessed textile fibres

  • Wastes from processed textile fibres

Wastes from power stations and other combustion plants (except wastes from management facilities, off-site waste water treatment plants and the preparation of water intended for human consumption and water for industrial use)

  • Gypsum

Wastes from manufacture of cement, lime and plaster and articles and products made from them

  • Gypsum

Wastes from anaerobic treatment of waste

  • Liquor from anaerobic treatment of municipal waste

  • Digestate from anaerobic treatment of municipal waste

  • Liquor from anaerobic treatment of animal and vegetable waste

  • Digestate from anaerobic treatment of animal and vegetable waste