Hydrogeochemical characteristics and importance of natural and anthropogenic influences on soil and groundwater in reclaimed land adjacent to Port Jackson, Sydney, Australia

Abstract

Major ion and trace metal concentrations and physicochemical parameters were measured over a full tidal cycle in groundwater from reclaimed land adjacent to Rozelle Bay in Port Jackson, Sydney, Australia. Materials used for reclaiming the land (construction material waste or dredged marine sediment) predominantly influenced the ion and trace element compositions of the groundwater. The redox behaviour and composition of the soil profiles influenced the behaviour of redox-sensitive elements in the groundwater, for example Mn and Fe. When the water table recedes in drier periods, oxygen ingress can lead to biologically catalysed oxidation reactions resulting in a reduction in pH and an associated increase in the concentration of some trace elements. The dredged marine sediment contains a considerable fraction of shell fragments, leading to elevated bicarbonate levels in the groundwater, which in turn limits some trace element and major ion concentrations. The groundwaters contain higher levels of many trace elements (Cu, Pb, Zn, As, Cr) than occur in seawater and the natural hydraulic gradient may lead to elevated concentrations of these elements entering the estuary.

Trace elements in streambed sediments of floodplains: consequences for water management measures

“…In addition, the CO 2 budget changes with the activity of plants and roots in the first few centimeters of the sediment profile. Carbon dioxide is resorbed in connection with the precipitation of rhodochrosite, additionally controlling the Mn concentration according to Suh et al (2003). This process is indicated by the relatively high amount of 1.2 g kg -1 calcium carbonate in the first 10 cm of the sediment core and a positive saturation index for CaCO 3 (SI 0.49).…”

Sydney Harbour: a review of anthropogenic impacts on the biodiversity and ecosystem function of one of the world

“…Davis and Birch 2010b). In addition, increased concentrations of metals in some areas of the Harbour may be associated with leachate produced in reclaimed lands of the Harbour (Suh et al 2003a(Suh et al , 2003b(Suh et al , 2004Fig. 4), although the magnitude of the leaching process has not yet been quantified (Hedge et al 2014b).…”

Temperature Fluctuations in a Landfill in Response to Periodic Changes in Surface and Tide-Driven Groundwater Temperatures

“…As a result many landfills in have been constructed in mangrove habitats making it even more harmful to the surrounding environment. It is therefore important to understand the complex nature of groundwater containing nutrients and heavy metals [9]. The fluctuation in ground water levels due to tidal flux is critical due to its impact on the buried waste and methane emission into the atmosphere.…”

“…The fluctuation in ground water levels due to tidal flux is critical due to its impact on the buried waste and methane emission into the atmosphere. Tidal fluctuations can affect groundwater behaviour up to a distance ranging from 21 m (lateral) [9][10][11] up to 1 km (lateral) [12] with a certain time lag [11,[13][14][15].…”

“…Tidal fluctuations are important as they may be linked to ground water discharge [14]. Groundwater may contain heavy metals and ion from landfills and reclaimed land [9]. Piezometers [16] and level sensor (PS21000) manufactured by Green Span (Australia) were used in study to understand the influence of tides on the groundwater.…”