Raw Worx PTY LTD was contracted to undertake remedial repair works to the Lands’ End Bridge, located on the Gold Coast, QLD. The bridge extends over Biggera Creek, which flows into the Broadwater, north-west of Wave Break Island and the Gold Coast Seaway. The creek is surrounded by high density residential development. Construction works undertaken included blasting of pier piles, removal and installation of timber walkway, replacement of rock armour, concrete crack repair and application of protective epoxy coatings.
Ecobalance was commissioned by Raw Worx PTY LTD to undertake marine environmental value activities inclusive of:
Water Quality Objectives (WQO’s) are defined by a set of variables that are designed to protect the Environmental Values (EV’s) of a catchment from the effects of pollution. They may be defined by a range of physical, chemical and biological variables as well as other measures of waterway condition such as erosion and/or riparian vegetation. They are based on scientific criteria and/or water quality guidelines but may be modified by other (e.g. social, cultural, economic) inputs. It is important to be able to identify WQO’s for a waterway in order to identify suitable criteria to assess water quality during construction activities. Trigger values can be used to assess the risk of adverse effects due to nutrients, biodegradable organic matter and pH in various ecosystem types. The guidelines used for assessing water quality within the land ends bridge construction site included:
Results were indicative of a waterway that is subject to moderate to high levels of urban contaminants and resuspension. However, it was concluded that in order to comprehensively assess water quality, a sampling regime should include at least a 24-hour period of continuous (i.e. daily mean values calculated) monitoring, conducted over consecutive days and seasons and include a detailed chemical analysis.