CPD Specifier May 2015 issue May 2014 | Page 9

The higher capacity dry lagoon, measuring approximately 100.0m x 10.0m x 2.0m, then allows managed return of captured surface water to nearby water courses. Because of the impermeability of the Bentomat liner, virtually no retained water is lost through percolation. Maccaferri Bentomat is a geosynthetic clay liner specifically designed for landfill and lagoon lining. It consists of a layer of natural Wyoming Granular Sodium Bentonite sandwiched between a woven and non-woven geotextile. It is self-sealing if punctured, has excellent slope stability and high chemical and climate resistance. The Bentomat was supplied to on 5.0m wide rolls and installed by Maccaferri Construction, the Company’s specialist subsidiary. The liner was overlain with a 300mm layer of sharp sand followed by a 200mm layer of compacted site won fill. These layers give added protection to the liner and eliminate any risk of it ‘floating’ due to back pressure of ground-water. The lagoon walls were constructed using Maccaferri twisted Gabions which were hand filled with l