A Petri Dish for E.Coli

Here are all the CSO Combined Sewage Overflow - a device that, when operating, pours combined rainwater & sewage into a waterway s in England, Wales & Scotland that 'overflowed' in 2024 - dumping raw or minimally treated sewage into fragile chalk streams, rivers, onto beaches and into shellfish areas.

Each colour represents a different Water Company, the size of each dot relates to how long each overflow was polluting - where the monitoring is disabled we show a medium-sized dot.

You might think that putting sewage into a river is something that never happens - who would do that? - but sadly its something that happens hundreds or thousands of times a day. The Environment Agency does publish this data, in complex formats that are hard to understand. We try to arrange this data, so that you can see how your local area, and places that you care about, are affected.

Have a look on this page to see what types of places are affected, or find your local constituency, or your water company, using the menus, and see how your local area is affected. Almost everywhere in the country is affected.

We use two sources of information - annual reports, published each April, which give figures for the previous year, and a real-time data stream. As there are differences in the naming of CSO Combined Sewage Overflow - a device that, when operating, pours combined rainwater & sewage into a waterway s we can't show them together mostly.

The figures, supplied by the water companies themselves, understate the problem, as the data is poorly collected by the Water Companies, with monitoring defective or in many cases completely absent.