# The Environmental Authorisations (Scotland) Regulations 2018, Paragraph 40: Protection of soil and water and leachate collection and sealing systems


(1) The landfill must be situated and designed so as to—
(a) provide the conditions for prevention of pollution of the soil, groundwater or surface water,
(b) ensure efficient collection of leachate as and when required by paragraph 39 of this schedule.
(2) Soil, groundwater and surface water must be protected by the use of a geological barrier combined with—
(a) a bottom liner during the operational phase of the landfill, and
(b) a top liner following closure and during the after-care phase.
(3) The geological barrier must comply with the requirements of sub-paragraph (4) and must also provide sufficient attenuation capacity to prevent a potential risk to soil and groundwater.
(4) The landfill base and sides must consist of a mineral layer which provides protection of soil, groundwater and surface water at least equivalent to that resulting from the following permeability and thickness requirements—
(a) in a landfill for hazardous waste—
(i) K ≤ 1.0 x 10 – 9 metre per second,
(ii) thickness ≥ 5 metres,
(b) in a landfill for non-hazardous waste—
(i) K ≤ 1.0 x 10 – 9 metre/second,
(ii) thickness ≥ 1 metre,
(c) in a landfill for inert waste—
(i) K ≤ 1.0 x 10 – 7 metre/second,
(ii) thickness ≥ 1 metre.
(5) Where the geological barrier does not meet the requirements of sub-paragraph (4) naturally, it may be completed artificially and reinforced by other means giving equivalent protection, but in any such case a geological barrier established by artificial means must be at least 0.5 metres thick.
(6) A leachate collection and sealing system to ensure that leachate accumulation at the base of the landfill is kept to a minimum must also be provided in any hazardous or non-hazardous landfill and must include an artificial sealing liner and a drainage liner greater than, or equal to, 0.5 metres.
(7) Where the potential hazards to the environment indicate that the prevention of leachate formation is necessary, surface sealing may be required taking account of the requirements in Table 14—
Table 14
Landfill category
Non-hazardous
Hazardous
Gas drainage layer
Required
Not required
Artificial sealing liner
Not required
Required
Impermeable mineral layer
Required
Required
Drainage layer > 0.5 metres
Required
Required
Topsoil cover > 1 metre
Required
Required
(8) The requirements of sub-paragraphs (3) to (7) may be reduced to an appropriate extent if on the basis of an assessment of environmental risks—
(a) it has been decided in accordance with paragraph 39(2) of this schedule that the collection and treatment of leachate is not necessary, or
(b) it is established that the landfill poses no potential hazard to soil, groundwater or surface water.

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Source: https://www.legislation.gov.uk/ssi/2018/219/schedule/13/paragraph/40 (the official version)
Page: https://openlegislation.uk/environmental-authorisations-scotland-regulations-2018/schedule-13/paragraph-40
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.