An impact assessment for urban stormwater use

The adoption of stormwater collection and use for a range of non-potable applications requires that the perceived risks, particularly those associated with public health, are addressed. Pollutant impacts have been assessed using E. coli and a scoring system on a scale of 0 to 5 to identify the magnitude of impacts and also the likelihood of exposure to stormwater during different applications. Combining these identifies that low or medium risks are generally predicted except for domestic car washing and occupational irrigation of edible raw food crops where the predicted high risk would necessitate the introduction of remedial action

Wastewater irrigation: the state of play

As demand for fresh water intensifies, wastewater is frequently being seen as a valuable resource. Furthermore, wise reuse of wastewater alleviates concerns attendant with its discharge to the environment. Globally, around 20 million ha of land are irrigated with wastewater, and this is likely to increase markedly during the next few decades as water stress intensifies. In 1995, around 2.3 billion people lived in water-stressed river basins and this could increase to 3.5 billion by 2025. We review the current status of wastewater irrigation by providing an overview of the extent of the practice throughout the world and through synthesizing the current understanding of factors influencing sustainable wastewater irrigation. A theme that emerges is that wastewater irrigation is not only more common in water-stressed regions such as the Near East, but the rationale for the practice also tends to differ between the developing and developed worlds. In developing nations, the prime drivers are livelihood dependence and food security, whereas environmental agendas appear to hold greater sway in the developed world. The following were identified as areas requiring greater understanding for the long-term sustainability of wastewater irrigation: (i) accumulation of bioavailable forms of heavy metals in soils, (ii) environmental fate of organics in wastewater-irrigated soils, (iii) influence of reuse schemes on catchment hydrology, including transport of salt loads, (iv) risk models for helminth infections (pertinent to developing nations), (v) microbiological contamination risks for aquifers and surface waters, (vi) transfer efficiencies of chemical contaminants from soil to plants, (vii) health effects of chronic exposure to chemical contaminants, and (viii) strategies for engaging the public.<br /

Energy Conservation Via Greywater Reuse for Power Plant Cooling and Wastes Minimization

Sustainable engineering brings about multidisciplinary solutions to environmental, sociocultural, and economic needs. Sustainable methods and technologies ensure the effectiveness of products, designs, and infrastructure, and minimize waste. Managing waste is critical in the successful practice of sustainable engineering. Success in the implementation of a waste management program must consider a very important strategy, namely, waste reduction which is highly dependent on social stewardship, education, and waste conversion. A sustainable program mix must include public policy, health management, and engineering. This paper presents a number of proven sources and techniques for wastes minimization and conversion and a discussion about the development of effective decision-making tools to implement the most feasible and cost-effective applications. Specifically, the conversion of waste as a resource is presented including the use of wastewater (greywater) for condenser cooling in a power plant; conversion of restaurant grease into biodiesel; the use of phosphate mine tailings as a road surface material; recycling and reuse of glass, metal, and plastics; reuse of rare metals from discarded computers; and the use of cattle waste as building materials. In all of these, the conservation of energy is realized practically. More emphasis has been focused on the use of greywater because it has direct impact on the energy–water nexus