Attenuation tanks can help to reduce, or even eliminate flooding, erosion, and damage caused by flooding during extreme rainfall situations.
Attenuation tanks, shoebox liners or SUDS (Sustainable Urban Drainage Systems) manage extreme rainfall in urban areas or in areas where large amounts of non-porous material stops natural water runoff into grass, soil and waterways. The storm water is collected by normal road gullies and temporarily stored for a period of time. The water is released in to the sewer network through a “control manhole” that only allows a controlled volume of flow through to the mains.
A Lift Pit Liner is constructed using 1mm polypropylene geomembrane, and can be welded on site or supplied prewelded to specified dimensions.
Polypropylene provides excellent flexibility, resistance to puncture, a lower co-efficient thermal expansion and being welded make it totally impervious to water ingress. The product lends itself to applications where high/variable water tables, standing water and water creating hydrostatic pressure areas are evident.
Construction of Lift Pit Liner
The manufacturing of the Lift Pit Liner commences when the length, width and height measurements have been obtained and signed off by the contractor installing the product.
The lift pit liner is heat welded together with a 50mm overlap joint running vertical in each corner, fusing the two membranes creating a homogenous material joint.
Around the topside of the lift pit liner a return flange of 150mm wide or greater, dependant on request, is then joined to the DPM by contractor. The type of sealant/DPM jointing material required will depend upon the type of DPM and the contractor should seek technical advice from Water-Land Solutions regarding this issue.
(*): All values – unless otherwise noted – are nominal values. Values in brackets are minimum values with the 95% confidence interval.
(a): Tolerance ± 10% - Special thickness available upon request.
(b): Dispersion only applies to near spherical agglomerates. 9 of 10 views shall be category 1 or 2. No more than 1 view from category 3.
(c): Standard test conditions: 190ºC / 5.0kg.
(d): Roll widths and lengths have a tolerance of ± 1%.