Goodgymmers from Barnet and Brent joined a huge and vibrant team of elite water activists and citizen scientists for an amazing project funded and supported by Imperial College. The project aims to capture river pollution data from roads after heavy periods of rain, to better understand just how damaging the chemicals from tyre erosion, petrol spills and similar toxic compounds can be to our water ecologies in north London.

The core team identified 50 locations along the River Brent, Silk stream Edgware Brook, Deans Brook and Mutton Brook, as well as a control sample from the Dollis Brook. Following rigorous safety training (and a fantastic tour of the lab at Imperial College) as well as training on how to collect uncontaminated samples, we then sat and waited for a period of dry weather, followed by sufficient rainfall to cause flow from major roads, like the North Circular, into the rivers.

Once the call went out, we rushed out in pairs to various locations to do our best to capture samples from the middle of the waterways before, during and after rain, to map pollution levels. In all, over March and April, we have gathered and delivered 99 samples to Imperial's research team.

The project is ongoing, aiming for a hefty total of up to 300 samples from target locations. We'll be narrowing down to the most polluted sites for follow up tests, so we can get a bit more data of how pollution from road surfaces changes over certain months, or builds up after longer periods without rain.

Meanwhile, Goodgym Barnet is still participating in River Watch , looking for pollution in local rivers. And if you want to get involved in river activism, you can contact Clean Up the River Brent (Curb), who can put you in touch with groups near you.

Goodgym Barnet also supports the Pymmes Brookers and Dollis Brookers, who you can find online, as well as Thames21, so keep an eye out for future missions.