What's in the Nadder? Focus - Dec

A full Victoria Hall heard a talk entitled “What’s in the Nadder”, where speakers from the Wessex Rivers Trust and the Nadder Valley Farmer Group presented the results of recent testing for phosphates, nitrates and bacteria. In addition, silt traps were used to check for the impact of soil runoff, which can smother in-river vegetation. All this focused on the Nadder, between Semley and Dinton, and included its tributaries.

The Environment Agency (EA) monitors water bodies to assign an ecological status based on biological, chemical, physical and hydrological criteria. In 2022, the Upper Nadder was rated as Moderate; while the Headwaters (up to Ludwell through the Donheads) were Poor. More recently, budgetary constraints have curtailed the amount of monitoring. So, the results of the work done by the Trust and Farmer Group allowed a reality check on the current situation.

Broadly, the results showed that the situation was little changed, but the good news is that there are improvement plans. Septic tanks are a feature of rural areas, treating sewage from one or more properties and then releasing it. But these discharges can sometimes be nutrient rich and pollute the river. Wiltshire Council is funding the replacement of old septic tanks under a project named “Revamp your Tank” to reduce that source of pollution. Farms are now inspected to ensure that farmers are complying with the regulations and given guidance on how to undertake improvements and best practice to minimise runoff into rivers.

But, as well as the contaminants mentioned above, pesticides, pharmaceuticals, cleaning products and other inputs get into our rivers. Sewage treatment works are designed to remove solids and return treated water to the river, but cannot deal with chemicals. Obviously, there is little we can do to prevent medications passing through our systems and into our wastewater. But it would help if we all thought carefully about what we put down our toilets, sinks and drains. For toilets, we should stick to no more than the three Ps (Pee, Poo, Paper). We have all heard about fatbergs created by cooking fats building up with solid objects (from cotton buds to nappies). The recent story about the woman fined for putting coffee down a storm drain is a prime example of thoughtlessness. Yes, it was only a small amount but if everyone did it…. All of us use water and all of us create wastewater, which eventually gets into the Nadder, so we all have a part to play.

​Andrew Graham