On the fourteenth of March 2024, Fiona Cartwright completed her monthly Water Quality Watch test at her monitoring site on the River Kennet near Newbury. The dissolved oxygen reading was within normal range. The pH was normal. But the nitrate level was 8.4 milligrams per litre — more than double the background average for that site over the previous two years of monitoring.
Fiona logged the result to the shared database and flagged it for review by our science team. Protocol requires a follow-up test within five days when a result exceeds 150 per cent of the two-year site average. Fiona returned four days later. The nitrate had risen further, to 9.1 mg/L. Phosphate was also elevated.
Our science team cross-referenced the result with the two upstream monitoring sites. Both were showing normal readings. The spike was localised to Fiona’s stretch. A report was submitted to the Environment Agency’s incident team that afternoon.
The EA investigated the following week and identified a cracked slurry lagoon on a farm approximately 800 metres upstream. The operator was served an enforcement notice and required to carry out immediate repairs. A follow-up inspection three weeks later confirmed the lagoon had been repaired and nitrate levels at the site had returned to background levels.
“I have been testing the Kennet for three years,” Fiona told us afterwards. “You get to know what normal looks like. When something changes, you notice. That is the whole point.”
The Water Quality Watch now has 2,800 active testers at 8,400 registered sites across the UK. In 2024, volunteer data contributed to eleven pollution investigations that resulted in enforcement action. None of those investigations would have begun without someone walking to a riverbank once a month and doing the test.