Unfortunately it has not been possible to continue making regular readings during the latest pandemic lockdown. Hopefully it will now be possible to build up a long term record of monthly monitoring.
Low river levels may be a factor influencing the readings. The most striking, and concerning, observation is that phosphate readings are high at all points from Cam Bridges downstream. Once more, the reason for this, either a point source or diffuse source, hasn’t been pinpointed. Conventional wisdom, at least locally, is that the spreading of slurry on fields is the cause but our group has no evidence to support this, either on this or on previous monitoring visits. It may be a factor at times but it would need to enter the Par River via the Treverbyn Stream tributary; however, results for the latter show 0 ppm for 2 of the 3 surveys conducted so far, with one reading of 300 ppm. The treatment works is being upgraded to treat sewage from the large development at Carclaze, which is a potential future concern, but otherwise does not seem to be causing pollution. We hope to test between Cam Bridges and Bridges to see if any sources of phosphate pollution can be found. One suggestion is to test water in the Charlestown Leat upstream from Cam Bridges which will be done, subject to access.