We have live data for Northumbrian Water so we can track what happens every day - given that overflows are supposed to happen on an 'exceptional' basis only - does the chart indicate that?

How does each water company compare? These are the totals by company for each. The totals are really high, counting things in hours doesn't make it very easy to think about. Here we show how many years of continuous sewage dumps happened in a single year, by water company.

It isn't like there are just a few outliers... the problem exists across the entire estate of water assets. Here we show a 'cumulative frequency diagram' - where the number of CSOs that dumped sewage for a time, or longer, is shown. You can see that many CSOs dumped sewage into a river for months and months.

Northumbrian Water is highlighted in the plot below

These water companies are responsible for managing sewage treatment and preventing pollution in our waterways.