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QUEENSWOOD RESERVOIR REHABILITATION www aquatan com 27 11 974 5271 aqua aquatan com

Repairs to the Queenswood Reservoir in Pretoria were necessitated by diagonal cracks in the walls of the reservoir through which leakage was occurring The Queenswood reservoir liner followed the successful installation of the same liner system in the 14Ml Clifton Avenue reservoir in 1999 for the City of Tshwane Metropolitan Municipality Aquatan was subcontracted for the installation of a specialised Ethylene Vinyl Acetate EVA Geomembrane Liner HYPERLINER on the floor and a geotextile HYPERLINER against the wall and around the columns The installation also included a Segmented HI DRAIN 750 Leakage Detector System The thickness of the HYPERLINER installed is 2 0mm and it is available in rolls of 4 0m seamless widths and 105m lengths Page 2 of 3 HYPERLINER has been successfully used in numerous potable water reservoirs across Southern Africa for many years HYPERLINER due to its amorphous nature which makes it stress crack free is also used for large thickener floor liners tunnel liners and basement liners Stefanutti Bressan Civils were responsible for concrete modifications to the inside of the reservoir to facilitate the installation of the liner HYPERLINER is suitable for this application due to its unsurpassed flexibility ability to accommodate anticipated movement durability absence of stress crack development its ability to conform to complicated three dimensional shapes typically present in reservoirs such as this as well as its exceptional resistance to tear and puncture It is further possible to vacuum form complicated column bases of the same material to minimise in situ welding to provide a more reliable installation The liner was installed as 11 0m X 7 0m modules against the walls secured at the top above the fullwater level and toe of the walls using stainless steel angles and mechanical anchors The liner hangs loosely against the walls and is moulded around the columns and column footings The individual liner components are precision welded together with Aquatan s unique and time proven welding machines to form watertight seams and a homogenous lining Geofabric 440g m2 protects the lining from chaffing and wearing against the concrete walls and columns and at the same time directs water

from potential leaks to the HI DRAIN 750 Leakage Detector System HYPERLINER HAS BEEN SUCCESSFULLY USED IN NUMEROUS POTABLE WATER RESERVOIRS ACROSS SOUTHERN AFRICA FOR MANY YEARS The liner on the floor is underlain by HI DRAIN 750 segmented into a number of compartments each with its own detection pipe HI DRAIN is a cuspated drainage system initiated and manufactured by Aquatan in South Africa to manage and facilitate the flow of liquid if any to the closest detection pipe Aquatan s unique Perforated HI DRAIN SA Pat Appl 2004 9723 was chosen for this application The Leakage Detection System on the floor slab underneath the liner is segmented to 1 simplify locating leakages through the liner that may exist after installation or be caused by mechanical damage during operation 2 to prevent leakage from entering the subsurface and 3 intercept groundwater and rainwater thus avoiding negative pressure on the liner system Page 3 of 3