Sewage sludge - Landspreading

What you must do

Check if you are in a nitrate vulnerable zone

In Northern Ireland all farmers must comply with rules under the Nutrient Action Programme.

DAERA: Nutrient Action Programme 2019-2022 Changes and New Measures

In Scotland you should find out whether you are in a nitrate vulnerable zone (NVZ). If you are in an NVZ you will need to follow certain rules, such as limiting the amount of organic and inorganic nitrogen fertiliser you use and keeping records.

Scotland: nitrate vulnerable zones (NVZs)

In Scotland, you must not spread slurry or manure, including sewage sludge:

  • within 10m of any ditch, burn, river, loch, wetland or coastal water (on sloping ground a wider buffer zone may be required).
  • within 50m of any spring that supplies water for human consumption or any uncapped well or borehole.
  • on waterlogged or snow covered ground.
  • on shallow soils (average depth of less than 40cm over gravel or fissured rock).

In January 2018 some changes were made to diffuse pollution regulations that may impact on the activities of your business.

The Water Environment (Miscellaneous) (Scotland) Regulations 2017

In summary, the changes to the regulations mean that the following activities are now covered by General Binding Rules (GBRs).

• The storage, transfer and application of slurry, manure and other fertilisers to land
• The storage and application of digestates and sewage sludge to land
• The use of plant protection products by all application methods
• The use of herbicides in or near to water to control invasive species
• The operation of sheep handling facilities when using pour on chemicals
• Specific types of work carried out to protect river banks from erosion
• The storage of agricultural fuel oil

Farming and Water Scotland – ‘Know the rules’ guides: slurry and manure

Use sewage sludge that has been tested

You must only use sewage sludge that has been tested according to the Sludge Regulations. You must check that you do not exceed the limit on the average annual rate of addition of metals in the sludge.

You must not spread sewage sludge on a field unless you have tested the soil according to the Sludge Regulations. This includes checking that the limit on the concentration of metals in the soil will not be exceeded by spreading the sludge.

In Northern Ireland these limits are listed in Schedule 2 of The Sludge (Use in Agriculture) Regulations 1989

Schedule 2 of the Regulations

In Scotland these limits are listed in the Prevention of Environmental Pollution from Agricultural Activity( PEPFAA), Chapter 5, Appendix 1  (Section 5 - Non-agricultural wastes and other imported organic wastes)

Scottish Government: PEPFAA Code

You must not spread sludge on land that has a soil pH of less than five.

You must follow all mandatory stock grazing, cropping and harvesting restrictions.

 The Safe Sludge Matrix should also be followed. 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 not be used on land used for food crops.

The following Safe Sludge Matrix restrictions are specific to sewage sludge and to land used to grow food crops or for grazing.

  • Sludge may only be applied to land to grow food crops if it has been “conventionally treated” or “enhanced treated”
  • Conventionally treated sludge must not be surface applied to grass for grazing.

The table below shows how long you must wait (column 3) before carrying out certain activities (column 1) on land where sludge has been spread

Table 1: Grazing and Harvest Periods

Activity Sludge Type Period (commencing on the date of the use)

Grazing animals or harvesting forage crops

Conventionally Treated Sludge (Must be deep injected or ploughed down only)

Enhanced Treated Sludge

 No grazing in season of application

Three weeks

Harvesting vegetables

Conventionally Treated Sludge

12 months

Enhanced Treated Sludge

10 months

Harvesting fruit and salad crops which are grown in direct contact with the soil and normally eaten raw

Conventionally Treated Sludge

30 months

Enhanced Treated Sludge

10 months

“Conventionally Treated Sludge” is sludge which has been treated to ensure at least 99% of pathogens have been destroyed.

“Enhanced Treated Sludge” is sludge which has been treated to ensure it is free from Salmonella and that 99.9999% pathogens have been destroyed.

You must give a sewage sludge producer information about any past sludge use by a different producer. This should include details of where, when and how much sludge was used and who supplied it.

Inform your environmental regulator immediately if sewage sludge enters a watercourse. Use the pollution hotline 0800 80 70 60.

Spreading sewage sludge on non-agricultural land

If you spread sewage sludge or septic tank sludge to non-agricultural land, you must register an exemption from waste management licensing.

For more information read our guidance on landspreading waste.

Good practice

Water UK and the British Retail Consortium (BRC) developed the Safe Sludge Matrix. It consists of a table of crop types, together with clear guidance on the minimum acceptable level of treatment for any sewage sludge which may be applied to that crop or rotation. Please note that your environmental regulator does not enforce the Safe Sludge Matrix.

The Safe Sludge Matrix

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Further information

The codes of good agricultural practice provide more advice on sludge spreading.

In Northern Ireland, see section 4 of the DARD code of good agricultural practice for water, air and soil.

In Scotland, see section 5 of the Prevention of Environmental Pollution from Agricultural Activity (PEPFAA) Code.

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