Springvalley Landfill Cap
Remediation Leachate Collection Drain
Location
Springvale South, VIC
Client
Greater Dandenong City Council
Duration of Project
July 2018 – September 2018
Contract Value
$450k
Shamrock Civil completed the construction of a groundwater interception trench and drain, at Springvale Park on Clarke Road, Springvale South (an old landfill site). The works were commissioned to monitor and collect water leaving site, to enable the council to develop the design of the larger capping project at the same site. The project involved excavation of a trench below the groundwater table and around live services. Trenching, shoring, dewatering, manhole construction, HDPE pipe welding and minor concrete works were required. Shamrock Civil coordinated a letter drop to inform the public of the project, and also liaised with multiple park users, to ensure security and safety of all personnel on site.
Scope of Work
The construction of groundwater collection drain including the following:
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Excavate groundwater drainage lines and pits
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Install groundwater pipework including valves and groundwater storage pits
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Gas lines to be installed above the pipework including a gas riser pipe
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Trench lines were to be lined with a filter geotextile and backfilled withdrainage aggregates, granular fill, clay liner, bentonite (around leachatestorage pits), subsoil and reinstate topsoil to original elevations
Project Complications & Achievements
Use of dumpy level over a GPS system provided cost savings, relocation of pit and drain line eliminated the need to remove trees which were originally obstructing the works. GPS system could have improved accuracy, but would have increased costs. The discovery of sandy material in some areas proved difficult to excavate the required trench depth without collapsing, so Shamrock Civil was forced to excavate much wider in the section to limit the volume of sand falling into the bottom of the trench. The design originally intersected with trees within the site, so Shamrock Civil were able to relocate some of the design to avoid removing trees while still conforming to the design parameters.
