March 2022 Results
Having changed the results graph this year to show all the sampling points the group were doing, the decision with West Country Rivers Trust was taken this month to reduce the amount of sampling, for a couple of reasons. Firstly, more sites were chosen last year to try to establish the source of phosphate pollution and this has now been done, our results suggesting the problem arises around the Luxulyan Sewage Treatment Works and continues downstream from there. Secondly, those sites that have been consistently clear of phosphates over the past year, or where results could be inferred from other sites (eg, Middleway Canal between Ponts Mill and Par beach) are less in need of monitoring. This saves on time and resources, both of which is needed to carry out river fly monitoring and bacteria testing.
The general outlook was more positive this month with reduced phosphate levels across all sites, though still following the same pattern of higher levels from Luxulyan down to the Valley. Nitrates continue to be within safe drinking water levels, but please don't drink the water on that basis!! Bacteria levels are registering as very high, but we need to do more work on this to check our methods and results. We continue to see evidence of otters and therefore, indirectly, fish. There is a healthy diversity of river flies which is also a good indicator of river health.
Many thanks to Roger Smith who produces the river monitoring reports.