Next generation water efficiency: looking over the horizon

After major investment during the Millennium drought, many Australian cities have become more resilient by diversifying their water supplies with desalination, water recycling, rain tanks, and importantly, increased water efficiency through both programs and regulations. The achievements in efficiency such as reduced per capita demand and success of large-scale demand management programs, are internationally recognised. However, with both Sydney and Melbourne heading towards mega-city status by mid-century, further increases in efficiency must be considered. This paper explores the technologies, behavioural interfaces and programs that could aid Australia’s next generation of water efficiency

Review of the Metropolitan Water Plan: Final Report

This report was commissioned by the NSW Cabinet Office to review the Metropolitan Water Plan 2004 (DIPNR, 2004a), and was undertaken by the Institute for Sustainable Futures at the University of Technology, Sydney and ACIL Tasman with technical advice from SMEC Australia. In February 2006, our interim review report (ISF, 2006) showed how the supply-demand balance in 2015 could be met with rain-fed supply and a suite of demand management initiatives, and how Sydneys water needs could be secured against the risk of severe drought by having the capacity to deploy groundwater and desalination

Influence of innate sludge factors and ambient environmental parameters in biosolids storage on indicator bacteria survival: A review

The potential health risks associated with sludge cake application to agricultural land are managed by controlling the levels of Escherichia coli (E. coli) bacteria which indicate the risk of pathogen transfer. Analyses undertaken following post-digestion sludge dewatering have shown unpredictable levels of E. coli increase in stored sludge cake. Presently there is limited understanding on environmental parameters controlling the indicator bacteria density in storage and the contributory effects dewatering may have. This review aims to establish the state of current knowledge on innate and environmental factors influencing E. coli dynamics and survival in biosolids. A key factor identified is the effect of mechanical dewatering processes, which transform the sludge matrix environmental conditions through the increased availability of growth factors (e.g. nutrient and oxygen). Examples of storage practices from the agricultural and food industries are also discussed as successful methods to inhibit bacterial growth and survival, which could be extrapolated to the biosolids sector to regulate E. coli concentrations

Disruption of cells in biosolids affects E. coli dynamics in storage

Achieving microbial compliance during biosolids storage can be complicated by the unpredictable increase of Escherichia coli. Thermal treatment during anaerobic digestion (AD) and the effects of dewatering may be a significant factor contributing to indicator survival. Shear forces present during dewatering may promote cell damage, releasing nutrient for E. coli growth. The effect of cell damage on E. coli survival was assessed in laboratory-scale thermal and physical disruption experiments. E. coli growth curves for disrupted treatments were compared with control conditions and quantified using flow cytometry and membrane filtration techniques. A significant difference (p < 0.05) in the level of damaged cells between control and disrupted conditions was observed. For thermal and physical disruption treatments, the peak of E. coli concentration increased significantly by 1.8 Log and 2.4 Log (CFU (colony forming units) g−1 DS), respectively, compared with control treatments. Research findings contribute to the understanding of bacterial growth and death dynamics in biosolid

Review of the Metropolitan Water Plan: Final Report

This report was commissioned by the NSW Cabinet Office to review the Metropolitan Water Plan 2004 (DIPNR, 2004a), and was undertaken by the Institute for Sustainable Futures at the University of Technology, Sydney and ACIL Tasman with technical advice from SMEC Australia. In February 2006, our interim review report (ISF, 2006) showed how the supply-demand balance in 2015 could be met with rain-fed supply and a suite of demand management initiatives, and how Sydney’s water needs could be secured against the risk of severe drought by having the capacity to deploy groundwater and desalination. Subsequent to that report, the NSW Government committed, among other initiatives, to increased recycling, groundwater and desalination readiness in the case of severe drought, and the removal of the potentially high cost Level IV/V drought restrictions from the suite of possible drought response options. The current report incorporates analyses of the more recent decisions and presents a deeper examination of implications, risks and opportunities as key considerations for the 2006 Metropolitan Water Plan. We have assumed that the objectives of the Metropolitan Water Plan remain unchanged — ensuring adequate supply to meet demand through the current drought and forward at least 25 years, and contributing to improved environmental outcomes. We have also worked with the assumption that these objectives are to be pursued with an eye to community acceptability and cost-effectiveness, inclusive of environment and user, as well as water supplier costs

Investigation on the risk of brucellosis linked to the production and consumption of milk in rural Cinzana, Mali

Background: The objective of this study was to assess the risk of brucellosis associated with different hygiene practices in the informal dairy production sector in rural Mali and local milk consumption habits. Methods: A cross-sectional study was conducted in 12 villages in the rural commune of Cinzana in Mali, and consisted of two complementary surveys. The first used a participatory approach, based on focus group discussion coupled with open question interviews during general meetings in villages. Its objective was to describe attitudes and practices related to milk production and consumption. The second was a prevalence survey conducted in parallel on humans and dairy herds. In each selected household, serum was collected from people consuming milk or in contact with livestock, after written consent was given. A questionnaire on livestock management practices and milk consumption habits was also administered to households included in the study. Two types of biological samples were collected from dairy cows and goat: raw milk and serum. Screening agglutination Ring test was carried out on milk samples. Rose Bengal test was performed on all human and animal sera. Positive Rose Bengal samples were tested by ELISA for confirmation. Human sera positive to ELISA were re-submitted to a Rose Bengal test by dilution. This confirmatory test allows differentiating between actual infection and exposure to the pathogen. Results: Positive results to the ring test were obtained for 5.9% (2/34) of milk samples from cows and 1.3% (1/75) of milk samples from goat. Only 1.0% (2/204) of sera from cows and 0.7% (3/404) of sera from goat were positive to the Rose Bengal test. The same test gave positive results in 0.9% (2/213) of human sera. All animal positive with Rose Bengal yielded negative results with ELISA, while one serological human case was found. This case was recorded in the village where the 2 positive cow milk samples came from, and where cattle herds are managed individually rather than by the community. The results indicated that 100% and 98.1% of respondents consume milk from cow or goat respectively without prior heating. Handling of abortion material was also common amongst respondents: 72.7% reported it with goats, 6.1% with cows and 11.3% with both species. Summary: This study confirms the presence of human and animal brucellosis in the rural area of Cinzana, Mali. The prevalence found in this study was very low despite widespread risky production and consumption practices. Further investigations on risk factors and preventive practices would be valuable