How clean are our rivers and streams?
We are lucky to have access to a number of rivers and streams which many of us enjoy for walking alongside, boating, fishing and even swimming. A wide variety of much-loved wildlife, from otters and water voles to kingfishers and dragonflies make their homes in our local waterways. But how safe is the water, and what effect is pollution having on biodiversity and public health? As part of the Nature Recovery Network Project, we have started monitoring water quality at seven sites around Eynsham and one in South Leigh. We began using qualitative kits from the Freshwater Habitats Trust (similar to the indicator paper used to assess pH levels), However, we have been fortunate enough to acquire a proper quantitative testing machine (a photometer), with which to measure the levels of a number of common pollutants – nitrates, nitrites, phosphates and ammonia. This has been bought with a grant from the Councillor Priority Fund, kindly facilitated by County Councillor Charles Mathew.
Wharf Stream at confluence of Chil Brook and Limb Brook
In addition to chemicals introduced into the water by agricultural run-off, recent newspaper reports, indicate the high number of discharges of raw sewage from combined sewer overflows (CSOs) – storm drains which allow excess rainwater, untreated sewage and runoff to discharge into waterways. There were over 200,000 instances of spills in 2019. An interactive map shows river discharges by area, with many cases relating to rivers which pass through our area. For example, discharges recorded in South Leigh leak into the Limb Brook, that joins the Wharf Stream at the Talbot Inn – we are recording the Limb Brook both in South Leigh and at the Wharf Stream on Long Mead. Only a small percentage of the combined sewer outflows have actually been fitted with monitoring systems, and although the Environment Agency should investigate if there are more than 60 discharges a year from a particular storm overflow, they rely on water companies to self-monitor.
A number of local Parish Councils are becoming increasingly concerned. In July, Stanton Harcourt PC invited the local group Windrush against Sewage Pollution (WASP), to give a zoom talk to its Council Meeting to which Eynsham’s Nature Recovery Network was invited.
Young surveyor testing water temperature in stream on Bartholomew School Playing Fields
Once we are beyond Covid, the scouts and schools will play a role in the monitoring of our freshwater habitats. Already, the project is being used for the Duke of Edinburgh Scheme and, as part of the recent Primary School Science week, we went in for a session with the Year 6 pupils taking in samples of water from our test sites. We used the simple testing tubes as well as pH indicator paper, and all pupils had an opportunity to try out a test and analyse and discuss the results. The children were enthusistic and knowledgeable about the streams in the local area, with some having visited them for paddling, pond dipping and even fishing. They were concerned about rubbish and pollution, and would also like to see cleaner water!
We will be collecting samples each month and recording levels of pollutants, as well as measuring acidity and temperature. Please email if you would like to join in, particularly if you are have a stream or pond in your village that you would like to monitor as part of the project. We are testing once a month in the first week of the month. Waterways are an essential part of our local environment, and they need to be monitored and cared for.