Environmental Authorisations (Scotland) Regulations 2018 draft - proposed amendments: consultation

Annex C Sewage Sludge: The Requirements for Recovery of Waste by Application to Land for the Purpose of Soil Improvements as set out in Schedule 18

8.1.1 In line with Sludge Review Recommendations 1, 6 & 9 the draft Regulations provide a series of prohibitions and restrictions to ensure environmental protection, implement the Sludge Directive and put elements of the Safe Sludge Matrix on a statutory basis.

8.1.2 Article 6(a) of the Sludge Directive requires that sludge be treated before being used in agriculture but provides a derogation such that untreated sludge can be injected or worked into the soil. The Sludge (Use in Agriculture) Regulations 1989 took advantage of that derogation, but we propose not to carry this forward into the new regulations. SEPA will be required to ensure no untreated sewage sludge, including septic tank sludge, is applied to agricultural land.

8.1.3 The regulations carried forward a requirement such that wastes must not be mixed with any material which would not itself provide benefit. This applies across all waste types, including sludge.

8.1.4 The following proposed changes apply across all waste types, including sewage:

• sludge used takes account of the nutrient needs of the plants and that the quality of the soil and of the surface and ground water is not impaired (Regulation 3(7) of the 1989 Regulations, transposing Art 8 Sludge Directive)
• the pH value of the soil shall not be less than 5 if sludge is to be applied (Regulation 3(5) of the 1989 Regulations)
• set values for the concentration of heavy metals in the receiving soil, and the maximum annual rate of addition, by prohibiting application where limits already breach or liable to be breached, and steps to be taken to ensure limits are not exceeded (regulations 3 and 4 of and Schedules 1 and 2 to the 1989 Regulations, transposing Sludge Directive Articles 4 and 5).

8.1.5 These provisions derived from the Sludge (Use in Agriculture) Regulations 1989 but need to be enhanced further, considering new science and experience of use. We propose to change the soil protection limits as follows.

• limits given in the table for maximum permissible average annual rate of Potentially Toxic Element addition over a 10-yr period kg/ha should be regarded as annual limits
• Zinc (Zn): 200 mg/kg limit extended to pH 5.5-7 for precautionary reasons. These are the values that are currently used in the Biosolids Assurance Scheme Standard.
• Cadmium (Cd): Reduction of Cd limit and introduction of pH related limits. Research has shown there is a high risk of exceeding the European Union Cd maximum permissible concentration in wheat at the present soil Cd limit (3 mg/kg), especially at low soil pH.

8.1.6 Article 7 of the Sludge Directive provides a series of requirements and prohibitions relating to the types of crops to which sludge can be applied and minimum grazing or harvesting periods after use. In line with the Scottish Government’s Sludge Review, these requirements are to be enhanced by bringing them in line with the Safe Sludge Matrix, a voluntary code of practice which has been in place for over ten years. The draft Regulations require that:

• no fruit or vegetable crops, other than fruit trees, shall be growing or being harvested in the soil at the time of use or application of sludge
• sludge may only be applied to land used to grow food crops if it is “conventionally treated sludge” or “enhanced treated sludge”
• “conventionally treated sludge” shall not be surface applied to grass to be used for grazing

8.1.7 Paragraph 2(2)(b) of Schedule 2 to the 1989 Regulations only requires soil sampling every 20 years. SEPA guidance on Paragraph 7 exemptions specifies that soil sampling data should be no older than 12 months at the time of submission (including renewal). However, older analysis up to three years prior to the submission of the notification is acceptable provided documentary evidence is supplied to show how other wastes/fertilisers applied since that date have been accounted for in terms of calculated application rates. The draft Regulations create an integrated approach.