From NRN's Own Water Quality Tester, Lucy Dickinson
Water lilies, Thameside.
Concerns about water quality has certainly hit the news recently and has evoked a heated debate in Parliament. The Nature Recovery Network and many other local groups are continuing to monitor our rivers and ponds, and to lobby our local MPs and Thames Water about the sorry state of our local waterways. In addition to our monthly monitoring of 10 locations in Eynsham for nitrates, phosphates, dissolved oxygen and pH, our neighbours in South Leigh are now using the Hanna equipment provided by the NRN to test the Limb Brook at different locations in their village (see their excellent Nature Notes page: https://southleigh.info/nature/limb-brook/index.php).
Alongside the Eynsham testing for chemical pollutants, I have continued to help with the Oxford Rivers project which is doing bacteriological testing and has submitted its application for bathing water status at Port Meadow (https://www.thames21.org.uk/improving-rivers/oxford-rivers-project/) . Unsurprisingly, the overall picture is not positive, with the data gathered showing that overall bathing water quality would be rated as poor for both e Escherichia coli (EC) and Intestinal Enterococci (IE), with levels being 2-3 times higher than those required for bathing water designation.
Getting bathing water status would mean that the Environment Agency would become responsible for regularly testing for bacteria and posting notices with updates on the water quality. The application was debated in parliament and a decision will be made early next year. This will not solve the problems of pollution from both bacteria and chemical pollutants, but it is helping to raise awareness and accountability, and (once they are working properly) the Twitter alerts (https://twitter.com/OxThamesSewage) will help people to know when there is a problem and when they should avoid swimming.
Our focus in the Nature Recovery Network is not just on sewage pollution and the safety of the rivers for human activity, but on pollution more generally and its effect on biodiversity. So, what have the results been like in Eynsham?
Nitrates
According to the Freshwater Habitats Trust, high levels of pollution for nitrates from are 1ppm (parts per million) or above. In the 16 months I have been testing, I have rarely seen levels below 1 ppm for any of our streams or rivers. The Fishponds do seem to have lower levels, perhaps because there is sufficient vegetation in the water to use up the nutrients through the nitrogen cycle. Levels in the Chilbrook, Limb brook Wharf Stream and Thames have been extremely high for the past few months, peaking in all those locations in October with levels of up to 24 ppm (in the Limb brook). We know from the South Leigh testing that nitrate levels in the Limb brook go up significantly after the point where the sewer substation is located. Obviously, a large responsibility lies with the water companies and our local councillors along with pressure groups and other communities have been active in challenging Thames Water to act.
What can I do?: Don't flush anything down toilets which might cause blockages - wipes, nappies and sanitary products. So-called 'fatbergs' mainly originate from cooking, so oils and fats should not go down the sink.
Phosphates
For phosphates the upper level beyond which water is considered highly polluted is 0.1 ppm. There have been no samples with levels below this at any location or time since I started testing, and levels are generally at least ten times higher. Worryingly, some of the highest levels are found in the spring water (I test three springs around the village, one of which joins the Chilbrook next to Station Road, and two in private gardens), as well as in the Fishponds (levels reached 19 ppm there in July last year). Phosphates can come from sewage, but may also be the result of agricultural run-off as well as detergents and other household substances and animal waste, so it is possible that some of these high levels are not primarily from the sewage overflows, but from the ground water.
What can I do? It is worth checking our own properties for leaks from appliances etc, and also thinking about what cleaning products we use (most commercial products are harmful to aquatic life, and can often be replaced with cheaper and less damaging alternatives, such as vinegar and sodium bicarbonate).
NRN Actions
All of this activity and data meant that we have been well placed to support the lobbying around the recent Environmental Bill, which MPs attempted to water down/dilute (sorry!) in order to minimise the legal requirements on water companies. While the public outcry about this has seemingly provoked a bit of a U-turn, it is worth noting that details are still sketchy on how Thames Water and other water utilities will actually be monitored and compelled to act on the seemingly endless releases of sewage through the combined sewer overflows (https://www.bbc.co.uk/news/uk-politics-59052995)
There have been a number of programmes about the issue including an ITV Tonight one (https://www.itv.com/hub/tonight/1a2803a9327) which includes contributions from both the Oxford Rivers project and Windrush Against Sewage Pollution. I have provided the information on the levels in the Chilbrook to EPC and EPIC, who have included them in their representations to OCC regarding the future developments proposed for Eynsham. Building new housing without huge improvements to the sewage system is likely to cause even more problems, and existing high levels of these pollutants have been cited elsewhere as barriers to development (e.g. https://www.bbc.co.uk/news/uk-wales-57512479).