The Ching

Sediment discharge from large outlet 5a
Poor mixing of 3 in flows

Most water coming from outfalls.
Last significant rainfall 26 Feb (nw3weather.co.uk)

Direct sample from small outfall pipe - Ammonia >3.00 flashing Phosphate 1.48
Direct sample from large outfall pipe - Ammonia 1.89 Phosphate 2.32
Direct sample from central stream - Ammonia 0.25 Phosphate 0.18

Pollution from the outfall pipes is quickly diluted by cleaner water coming under the bridge from upstream of Whitehall Road

Scum on the water surface for 50 yards downstream of the outfalls. Reported to Thames Water who visited and closed the job within 2 hours (case number 00835587)