England’s chief medical officer Chris Whitty has called out MPs for overlooking human health issues when drafting legislation relating to sewerage.
Whitty called for a refocus on health within wastewater legislation, which is currently framed around environmental targets.
He said the current legislation solely focusses on environmental issues, which is particularly frustrating as sewerage networks were designed originally to benefit public wellbeing.
Specifically, sewerage networks were designed in the UK in the mid-18th century in response to cholera outbreaks being linked to poor hygiene.
Whitty, who became a household name during the pandemic and regularly appeared in Covid-19 daily briefings alongside Boris Johnson, said now is a prime opportunity to address potential risks from faecal matter in effluent because public and political interest is high.
Speaking at The Royal Society, he explained that while the level of harm to human health from faecal matter in waterways remains largely unknown, bacterial microbes are undoubtedly problematic.
“There is a large gap in knowledge, we simply don’t know what the effects are or what the hazard is,” Whitty said.
Despite that gap, Whitty said human faeces posed a greater risk to human health than from animal waste and that exposure to even a small amount of waste containing harmful bacteria could cause a serious infection. This means pathogens cannot be diluted in the way that toxins in waste can be.
“We need to work out how big is the problem and what would be an appropriate level of response,” Whitty said.
“I was very struck that almost all the legislation – and therefore what water companies work to – is all environmental. Despite the fact the principal reason we have a sewerage network is human heath.
“We should think seriously about what is an appropriate and proportionate response in terms of reducing human pathogens, if there is a risk.”
He said the Royal Academy of Engineering was developing an understanding of the steps that could be taken to reduce potential risks from pathogens in wastewater.
Whitty’s words were echoed by David Butler, professor at the University of Exeter who stressed the need for attention to public health to be renewed in engineering.
Water and sewerage companies are required to monitor discharges of treated sewage effluent from wastewater treatment works. The Environment Agency stipulates samples should be analysed for biochemical oxygen demand, chemical oxygen demand as well as phosphorus and nitrogen.