River Mel Restoration Group

In last month’s edition of Meldreth Matters, we wrote about our concerns of possible pollution of the River Mel arising from the Melbourn Sewage Treatment Works (STW), which discharges its treated effluent into the River Mel just upstream of the railway bridge in Meldreth. Because of this concern, we were offered the chance to join forces with the Cam Valley Forum (a Cambridge based group) to carry out some sampling of water taken at various sites along the river Mel, as part of a larger study of the various tributaries of the Cam. We received the results just as the publication deadline for this issue approached, so we have not had a great deal of time to study them or their implications in depth, but there is a large increase seen in the number of indicator bacteria found in the samples taken 100 metres downstream of the sewage outlet when compared with “normal” background samples taken from the river 50 metres upstream of the outfall. A similar disparity is found when measuring phosphate levels in the water. Our understanding, and we are certainly not experts, is that the indicator bacteria are not themselves harmful, but that they are present in the human gut where they exist alongside pathogenic (disease causing) bacteria. They are widely used as an indicator of faecal contamination in water. They are also organisms that can be detected in water reliably and at low concentrations. The results are shown in the table below. They are worse than we were expecting…

Sampling Site

Count of faecal indicator bacteria (coliforms inc. Escherichia coli – most probable number (MPN) per 100ml; enterococci – colony forming units (CFU) /per 100ml) Phosphate-P (SRP)

E. coli Total coliforms Enterococci River Mel, Meldreth, 50m upstream of Melbourn STW outfall 105 436 31 <0.031 River Mel, Meldreth, c. 100m downstream of Melbourn STW outfall 8,164 48,840 1300 1.302 River Mel, North End Meldreth 548 2,481 150 0.228 River Mel, Malton, just upstream of confluence with the River Rhee 411 2,613 170 0.158

The samples were taken in January at what we estimated to be a normal winter flow rate, i.e. the river was not in flood. We assume that the levels of any pollutants would be higher if sampling took place during the summer months when the flow of water in the river is often much reduced. We have a meeting scheduled with representatives of the Environment Agency to discuss these findings and our concerns about the increasingly low flow rates seen in the Mel during the summer months. The meeting will have taken place by the time you read this, so we hope that we may have more relevant information to report soon. The Cam Valley Forum is also hoping to complete another round of sampling soon, in order to produce a more robust set of data. We hope that if you are not already a member, that you might consider joining the River Mel Restoration Group, either as a non-active supporter or as a member of one of our working parties. Membership is £10 per year per household.

Sandra Webb River Mel Restoration Group info@rivermel.com

A10 TIMBER CO.

For Timber & Sheet Material

Graded Timber Mouldings & Flooring Decking & Fencing Insulation Cutting & delivery service All enquiries welcome.

Barwick Ford Ware, Herts. SG11 1AL Tel: 01279 842016 e: sales@a10timber.co.uk w: www.a10timber.co.uk

My name is Kim, a caring and experienced dog sitter who can also care for other pets in your own home. Holiday house checks with pets or not. References available. Insured. Having owned animals all my life, I am passionate about your pets’ welfare and happiness. Pets are Family. Please call or text Kim 07737 155554.