Liner

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A liner is sometime incorporated into non-infiltrating practices such as stormwater planters, or has also been applied in permeable paving installations where seperation from the native soils and groundwater was required.

  • Waterproof containment can be created using a plastic membrane/liner (HDPE or EPDM are common materials).
    • When the membrane is being used directly in the ground, punctures from stones can be prevented by compacting a layer sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm. (30 - 50 mm) over the soil prior to installing the membrane.
    • Alternatively, a manufactured cushion fabric (geotextileFilter fabric that is installed to separate dissimilar soils and provide runoff filtration and contaminant removal benefits while maintaining a suitable rate of flow; may be used to prevent fine-textured soil from entering a coarse granular bed, or to prevent coarse granular from being compressed into underlying finer-textured soils.) can be employed for this purpose.
    • The top surface of the membrane must also be protected from stone and gravel being used for inside the BMPBest management practice. State of the art methods or techniques used to manage the quantity and improve the quality of wet weather flow. BMPs include: source, conveyance and end-of-pipe controls.. Again, sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm. or a cushion fabric may be used.
  • When a pipe is used to provide drainage from the BMPBest management practice. State of the art methods or techniques used to manage the quantity and improve the quality of wet weather flow. BMPs include: source, conveyance and end-of-pipe controls. cell, a 'pipe boot' should be sealed to both the pipe and the liner to prevent leaks.