Pressure is mounting for the establishment of inland bathing waters and for the 'right to swim in all waters'. The conventional approach to achieving standards for faecal indicators organisms in receiving waters is disinfection of effluents - usually with UV. Equally, one of the possible responses to the perceived risk posed by antibiotic-resistant bacteria (ARBs) in effluent might also be to provide disinfection. This project will assume some scenarios and develop possible national costs, both for totex and carbon

Environmental Regulators are starting to move towards more ‘end of pipe’ permitting of hazardous substances. For example, investment cycles, specifically AMP8 will see the introduction of nanogram level limits on Cypermethrin and microgram limits on some very hard to remove dissolved metals.

The 3 rounds of the Chemical Investigations Programme have identified the presence of certain hazardous substances in sewage and biosolids. CIP4 will monitor for an expanded range of substances and will potentially find more, at levels that give rise to environmental concerns.

Technology trials conducted under CIP2 revealed that many of these hazardous chemicals are very difficult to remove from sewage effluent using ‘end of pipe’ processes and the technologies themselves are very expensive. Furthermore, no single technology would remove all the chemicals of concern and many simply transferred the chemicals of concern from effluent to biosolids, thereby moving the problem not resolving it.

If we are unable to develop improved source and pathway control measures, then our only option for managing new chemicals permit limits is going to be expensive end of pipe treatment.

One option for reducing the chemical burden on sewage works and, ultimately, the environment is to remove substances of concern at point of entry into the sewer. The premise of this proposal is that there are technologies that could be deployable to treat low volume inputs that would be completely impractical to install at a sewage works

Water companies are facing a 'perfect storm': After a wet winter, storm overflows are very high on the political agenda; Wild swimmers expect better protection, and pressure mounts for more inland bathing waters; the Covid-19 pandemic has generated massive interest, not just in pathogen surveillance but in the 'risk' attached to discharges, both continuous and intermittent; there remains interest in revising standards for bathing and shellfish waters, to recognise pathogens rather than indicators; qPCR is now a routine approach for detecting the signal of any organism; the spread of antimicrobial resistance through wastewater and biosolids, although unproven in scale, also sits high on the agenda; reuse schemes are a larger part of water resource management, be it for potable or agricultural use; and the microbial quality of biosolids will always be of concern to stakeholders and regulators.

Do we understand this evolving framework and how should we respond? We are, after all, primarily concerned with the protection of public health - is gaining a better understanding of this an area we should be more active in promoting? How would we respond if challenged to reduce the perceived 'risk'? Do we even know if there is a 'risk'?