I believe there are three approaches. Firstly, whoever owns manhole cover assets needs to check individual installations for any applicable low-leak requirements – including their current capability – and seek to either source the low-leak feature or replace their cover assemblies where a vulnerability is discovered.
Secondly, the Sewers for Adoption (The Code) regulations need to be more specific about the meaning of ‘low-leak’ when referring to manhole covers fitted on foul-only sewer systems. Currently, it specifies low leak capability for such systems but fails to quantify what this means in volume leakage terms. Due to this ambiguity, it’s currently left to the manufacturer's discretion as to what constitutes a suitable low-leak feature.
And thirdly, the government needs to consider implementing robust policing of relevant legislation that ensures low-leak features are used as a matter of course on foul-only sewers which, of course, is then likely to result in them becoming more economical to fit.
Irrespective of this, it’s encouraging to see so much government and industry discussion around the issues of climate change and flooding, and a review of water utility specifications to ensure the inclusion of low leakage equipment on foul sewers can only improve the situation for all of our benefit.