This report provides a visual summary of key chemical indicators, ammonia, phosphate, and conductivity, across all Ripple Effect monitoring sites. Each figure shows how these parameters have changed over time at each specific location, based on monthly water quality surveys.

Site codes indicate location:
FR: Forest Row stretch
HF: Hartfield stretch
GB: Groombridge stretch

Axes:
Left axis: Ammonia and phosphate concentrations (ppm)
Right axis: Conductivity (µS/cm)
X-axis: Month and year of sampling — useful for spotting seasonal patterns and long-term trends.

Healthy Water Quality Thresholds:
Ammonia: < 1 ppm
Phosphate: < 0.1 ppm
Conductivity: < 500 µS/cm (sudden changes may signal pollution)

How to Interpret the Plot

Use the plot to identify unusual spikes or drops in water quality indicators, which may suggest:

Ammonia: Toxic at high levels; often linked to agricultural runoff or industrial discharge.
Phosphate: Elevated levels may indicate sewage or nutrient pollution, potentially leading to eutrophication.
Conductivity: Natural variation is expected, but sharp increases may point to chemical contamination or salt intrusion.



GLOSSARY


Water Parameters


Conductivity is a measure of water quality and is affected by the presence of dissolved solids such as those from sewage effluent. Conductivity naturally varies between 150 and 500 μs/cm; above this range could indicate water not suitable for certain species. A sudden change may indicate the onset of a polluting discharge.

Phosphate is a common constituent of fertilisers, manure, industrial effluent, and organic wastes in sewage. In excess it can cause a reduction in dissolved oxygen in rivers, caused by excessive algal growth. Without dissolved oxygen in the water, aquatic animals cannot survive.

Ammonia is an important natural resource in nature, but high levels can be toxic, causing lower reproduction and growth or death. It can be discharged into rivers from a range of sources including agricultural fertilisers and sewage effluent. It’s important to measure temperature at same time as this can impact the levels found in freshwater. Concentrations in unpolluted rivers range from 0.2 to 1.0 ppm. Tests with a reading of 3.0 ppm or above should be repeated to confirm, then reported to the EA.