Wastewater Recycling Risk Assessment

Summary

​Safe wastewater recycling requires potential health risks to be reduced to acceptable levels. Health-based targets set the benchmarks for establishing the safety of water at the point of use. This Wastewater Recycling Risk Assessment quantifies the risk associated with options for the reuse of abattoir process water by applying the principles of quantitative microbial risk assessment (QMRA) to a range of theoretical scenarios to identify actions required to meet health based targets.

The first stage of the risk assessment involved a screening level risk assessment, estimating the level of risk associated with the reuse of abattoir process water from a range of points within the meat production process. A literature review identified a number of pathogens relevant to beef production. Initially, in the absence of actual pathogen data from abattoir process water sources, a range of pathogen concentrations were adopted and the risk associated with a range of uses was calculated to provide a basis for further investigation. Pathogen reduction requirements were estimated to give an indication of the treatment required to make the process water suitable for the use. Using generic pathogen reductions achieved by treatment technologies, options for treatment can be identified.

The second stage of the risk assessment was to undertake a monitoring program to quantify levels of pathogens in a range of process water streams. The results have been compiled into a site-specific risk assessment and guidance of establishment of a hazard analysis and critical control point (HACCP) framework to manage risk.

The results of this assessment can be used to identify the options that are available to abattoirs and can be further investigated through site specific assessment.