Greywater irrigation as a source of organic micro-pollutants to shallow groundwater and nearby surface water

Increased water demands due to population growth and increased urbanisation have driven adoption of various water reuse practices. The irrigation of greywater (water from all household uses, except toilets) has been proposed as one potential sustainable practice. Research has clearly identified environmental harm from the presence of micro-pollutants in soils, groundwater and surface water. Greywater contains a range of micro pollutants yet very little is known about their potential environmental fate when greywater is irrigated to soil. Therefore, this study assessed whether organic micro-pollutants in irrigated greywater were transferred to shallow groundwater and an adjacent surface waterway. A total of 22 organic micro-pollutants were detected in greywater. Six of these (acesulfame, caffeine, DEET, paracetamol, salicylic acid and triclosan) were selected as potential tracers of greywater contamination. Three of these chemicals (acesulfame, caffeine, DEET) were detected in the groundwater, while salicylic acid was also detected in adjacent surface water. Caffeine and DEET in surface water were directly attributable to greywater irrigation. Thus the practice of greywater irrigation can act as a source of organic micro-pollutants to shallow groundwater and nearby surface water. The full list of micro-pollutants that could be introduced via greywater and the risk they pose to aquatic ecosystems is not yet known

Irrigated greywater in an urban sub-division as a potential source of metals to soil, groundwater and surface water

Increased water demands in dry countries such as Australia, have led to increased adoption of various water reuse practices. Irrigation of greywater (all water discharged from the bathrooms, laundry and kitchen apart from toilet waste) is seen as a potential means of easing water demands; however, there is limited knowledge of how greywater irrigation impacts terrestrial and aquatic environments. This study compared four greywater irrigated residential lots to adjacent non-irrigated lots that acted as controls. Accumulation and potential impacts of metals in soil, groundwater and surface water, as a result of greywater irrigation, were assessed by comparing measured concentrations to national and international guidelines. Greywater increased concentrations of some metals in irrigated soil and resulted in As, B, Cr and Cu exceeding guidelines after only four years of irrigation. Movement of metals from the irrigation areas resulted in metal concentrations in groundwater (Al, As, Cr, Cu, Fe, Mn, Ni and Zn) and surface water (Cu, Fe and Zn) exceeding environmental quality guidelines again within four years. These results are unlikely to be universally applicable but indicate the need to consider metals in greywater in order to minimize potential adverse environmental effects from greywater irrigation

Annual Report 2016-17

The Great Barrier Reef Marine Park is one of the best managed and one of the most important marine environments in the world. It is home to a wide range of plants, animals and habitats of special beauty and international interest. Under the Great Barrier Reef Marine Park Act 1975, the Great Barrier Reef Marine Park Authority provides for the long-term protection and conservation of the environment, biodiversity and heritage values of the Great Barrier Reef Region. Its protection is not only important for the future of the marine environment, but also for the many communities and industries that depend on it for their livelihoods

Compatibility matters: Assessing the risks of built heritage cleaning

Today, heritage conservation is a discipline torn between the objectivity of its material questions and the subjectivity of its stakeholders and practitioners, inherent to the fact that conservation is, first and foremost, a cultural act. Most current conservation perspectives advise for (conservation) decisions to be based on the significance of the heritage object. Following this approach, different management tools have emerged to assist conservation at site, local, national and international levels. Quite the opposite, in what concerns interventions, conservation is still largely viewed as an objective material problem, and decision-support tools at this level are still mainly focused on performance assessments. An exception to this rule is the Eight-step Planning Model, complemented by the (In)compatibility Assessment Procedure, proposed by Delgado Rodrigues & Grossi, which attempts to bridge the gap between the macro and micro levels of heritage conservation planning. Compatibility has been gathering momentum as a conservation principle, but it has been mostly dealt with from a purely material perspective and is still insufficiently defined, especially in scopes beyond product testing. Borrowing from the aforementioned (In)compatibility Assessment, the research presented herein argues that compatibility is an adequate operative concept to assist decision making and guide conservation interventions. The key for using the principle of compatibility at this level of heritage conservation is to link it to the significance of the (conservation) object. This is demonstrated by proposing a procedure for the planning of built heritage cleaning based on the assessment of its risks towards significance; using risk analysis as a development tool, this procedure intends to frame the subjectivity of decision making in heritage cleaning. From this research, it follows that the principle of compatibility may constitute a valuable bridge between the objectivity and the subjectivity of heritage conservation