A Splash of Science: Results from Our Water Blitz Weekend

Over our Water Blitz weekend, New Forest Friends of the Earth led a wide-ranging survey of local rivers, streams and brooks—from Chewton Bunny in the west to East Boldre in the east, and from the coast at Barton and New Milton  up to Testwood. It was a big effort, and thanks to everyone’s involvement, we now have a valuable snapshot of water quality across the New Forest.

In total, 11 sites were tested. The good news is that most streams showed only moderate levels of nitrates and phosphates, suggesting relatively low nutrient pollution. However, there were a few notable exceptions, including East Boldre, Danes Stream, and Bartley Water, where higher readings may point to localised pollution sources. All nitrate and phosphate results have been entered into the national database and are available at https://fww-earthw.hub.arcgis.com/pages/great-uk-waterblitz-results

At five of the sites, we also tested for E. coli, an indicator of faecal contamination. We were lucky enough to be given ‘R cards’, a relatively new method of testing for E coli. Several locations showed elevated levels, but the unenviable top spot went to Walkford Brook at Chewton Bunny, with a reading of 2366 CFU*,well above the safe threshold of 1000 CFU for bathing water. Second place went to Avon Water at Gordleton with 1166 CFU, also above the safe bathing threshold. Third place was taken by Beaulieu River at Lyndhurst with 666.6 CFU. Neither this, nor the result of 533 CFU at Bartley Water where it flows through a nature reserve in Calmore, are good. A high reading at Brockenhurst is thought to be anomalous and due to animal excrement.

This kind of work requires team work and attention to both safety and accuracy, so working in pairs was essential. We were especially pleased to be joined by volunteers from other groups, including Eco Sway and the CET, who helped make the weekend a real collaborative success.

Our E. coli data from the R-cards have been uploaded and, along with all other UK results, will be published in a report we hope will be shared with us by the end of May. 

A big thank you to everyone who took part. Your care and effort are helping to protect the water quality of our precious New Forest environment.

Footnote

*CFU stands for colony-forming units per 100 millilitres of water. It measures the number of viable E. coli bacteria that could potentially cause illness

For recreational waters (like rivers or streams where people might paddle or swim), the UK Bathing Water Directive (based on EU standards) considers:

Excellent quality: less than 250 CFU/100 ml

Good quality: up to 500 CFU/100 ml

Poor quality: over 1,000 CFU/100 ml

Anything over 1,000 CFU is considered unsafe for bathing, especially for children or anyone with open cuts or a weak immune system