The Protocol, published this March, will allow accredited composters to store, transport or use finished compost without having to meet waste licensing controls for that material (see letsrecycle story).
 A Jeantil EVR21-15 spreader applying compost to land, recently supplied to Lincolnshire-based MEC Recycling by Rustons Engineering. Under the quality protocol, such an operation would require soil testing |
For composting companies to comply with the protocol, they will be required to test soil on which the compost is used.
Dr Richard Swannell, director of organics at the Waste & Resources Action Programme (WRAP), who has been developing the protocol with the Environment Agency and the Composting Association, said information on soil testing available online was being updated.
Tests
The Protocol states that land mangers are responsible for carrying out soil tests for heavy metals or Potentially Toxic Elements (PTEs) before the first compost application is made, in order to ensure the process is environmentally safe.
Explaining the requirement, Dr Swannell said: “The sampling analysis must be recent and representative of the area of application of compost. Soil analysis within the last five years can be used provided that no significant quantities of sludge, compost, manure or other PTE-containing materials have been added since the last soil sampling and analysis.”
The clarified guidance will state that there are seven PTEs listed in the code of practice for the Agricultural Use of Sewage Sludge and if the soil analysis reveals that the material reaches a “75% trigger level” for one or more of these PTEs, then the soil will need to be tested again.
Dr Swannell said: “Once the soil has been re-tested, the 75% trigger level may not in practice have been reached, but caution should still be exercised when adding further compost.”
In this situation, soil sampling and analysis should be carried out more frequently to ensure that the specified soil PTE limits are not exceeded, he said.
Samples
The clarifications will also explain the number of soil sub-samples that need to be collected under the soil testing requirements. “Soil samples should be representative of the ‘uniform’ area (maximum of 50 hectares)”, Dr Swannell stated. These samples should be collected under the conditions laid out in Defra's Fertiliser Recommendations.
As a minimum, 25 individual sub-samples are needed for each ‘uniform’ area. These need to be thoroughly mixed up together before sending one final sample from the mix for analysis by a suitable laboratory.
The chosen laboratory will advise on the quantity of final sample required.
Emily Nichols, technical manager at the Composting Association, who has also been involved in development of the Protocol and guidance, said: “The field or fields that comprise the 'uniform' area must be similar in terms of soil type, previous crops and application of manures, fertilizers and other wastes, since the last time the area was sampled and tested. These factors influence nutrient budgeting, an important aspect of good agricultural practice.”
| Related links: |
The guidance is likely to be updated in the next week.
The Quality Protocol will come into force on 11 May – the final day of Compost Awareness week.
Register for free to comment