Emerging Contaminants Monitoring: Where Do We Start?

Davies, T. (Beca HunterH2O), Carlinet, C. (Watercare Services Limited), and Dockary, B. (Watercare Services Limited)

Emerging contaminants, or perhaps more aptly, contaminants of emerging concern (CECs), are a growing consideration in in all aspects of the water cycle. This is not only due to human impacts on the water cycle and release of a large variety of new contaminants, or increases in the prevalence of naturally occurring contaminants due to climate change, but also due to the increased speculation of risk that comes with better analytical techniques and greater knowledge of a range of contaminants at “trace” concentrations that have likely gone undetected before now.

Watercare are currently investigating the potential for incorporating recycled water into their future source water portfolio, and as part of this piloting of a purified recycled water (potable) treatment plant will beundertaken to gather data and inform future planning decisions. To get on the front foot of addressing the growing considerations in the emerging contaminants space for their long-term recycled water plans, Watercare plan to include monitoring for CECs as part of the recycled water pilot plant study. By including this monitoring, the intent is to address concerns around CECs and provide evidence for what is in the catchment, and ultimately improve the understanding of source risks and the effectiveness of treatment processes.

However, the sheer number of potential CECs that may need to be considered in this kind of monitoring plan make this a daunting task. Particularly in the recycled water space, there are potentially thousands of CECs that could possibly be present in the various feed water sources, and it would certainly be an impressive monitoring budget that could sample for all of them at any sort of regular interval. Laboratory capability and capacity also needs to be considered. The question we had to ask ourselves was: ‘how can a list of potentially thousands of contaminants be narrowed down to an affordable and manageable sampling program while still addressing the dangers and risks posed by all CECs? ’.

After conducting a literature review to develop a long list of potential CECs to consider for monitoring, Watercare engaged Beca HunterH2O to help in narrowing down the long list to a much shorter one that still provides a risk-based approach to obtaining solid evidence on CECs, whilst not breaking the monitoring budget. 

This case study provides an overview of the approach Watercare and Beca HunterH2O are taking to achieve this, presented in the format of a guidance note on how others can apply the same principles to developing their own monitoring approach for CECs. In other words, this is how we went from a very long speculative list of emerging contaminants to an actual plan for collecting evidence, and how you can do it too!