FreshWater Watch sites

FreshWater Watch is a citizen science scheme run by Earthwatch, which operates across the UK and the globe.

The method is the same everywhere: volunteers measure concentrations of nitrate and phosphate using colour-change water chemistry testing kits, estimate turbidity using a Secchi tube and record visual observations of the waterbody, such as signs of pollution and surrounding land use.

The tests are used as a 'health check' of the waterbody. FreshWater Watch guidelines are that readings above 0.1mg/l phosphate and 1mg/l nitrate indicate poor ecological status.

FreshWater Watch sites do not measure as many parameters as the Environment Agency sites, nor are the readings as precise, but they are still a very useful complement. FreshWater Watch citizen scientists as a collective can monitor many more sites than the Environment Agency, and more frequently.

Phosphate and nitrate are given as ranges with error bars. Phosphate is measured “as Phosphorus” (PO₄-P) and nitrate “as Nitrogen” (NO₃-N). To convert the readings, use the following formulas:

NO₃ = NO₃-N × 4.42

PO₄ = PO₄-P × 3.066

If you want to become a FreshWater Watch citizen scientist yourself, find your nearest group on the Take Action page or visit FreshWater Watch.