Nutrient Pollution

Every month, at 10 sites around the Upper Itchen, we take water samples and test them for 5 determinands, including Phosphate, Nitrate, Ammonia and Conductivity, as well as Temperature.  This provides insight into excess nutrients which we know are present in our chalk streams.  Although Phosphate and Nitrate are essential for plant growth, excess from agriculture and human waste can cause algal blooms and other negative effects on the ecosystem.

You can learn more about nutrient pollution, where it comes from and how we measure it, on this page.

The data we gather is not intended to replace the statutory monitoring undertaken by the Environment Agency or the Water Companies, or to directly challenge their data.  However, official monitoring is limited, resulting in big gaps in our understanding of water quality.  Our data is made available here to help to fill these gaps.