The Natural Environment Research Council has warned that several rivers in the UK could be highly polluted, after researchers discovered that tonnes of ammonium reach the River Thames every year from an Oxford wetland.
New research published in the journal Science of the Total Environment has found out that at Port Meadow, northwest of Oxford, around 27.5 tonnes of ammonium from landfill end up in the River Thames each year. Scientists warn that the same could process could be occurring in other sites around the country.
The lead author of the study Daren Gooddy, of NERC’s British Geological Survey said, “We’ve been getting rid of waste for an awful long time. Since Victorian times, we’ve been putting it into landfill and ad-hoc waste dumps on the edge of our towns and cities, often on the fringes of floodplains.
“There are 11 landfill sites at Port Meadow alone. If you scale that up for the whole of the UK, then you’re probably talking about thousands of them.”
Scientists sampled the water in May 2010 and August 2013 and attribute the tonnes of ammonium to household waste.
Ammonium breaks down into nitrogen, which can then trigger excessive algae growth, capable of destroying aquatic life and even affecting human health, through the production of toxins.
The research explained that although UK landfills are treated with a thick layer of clay to avoid chemical contamination in the environment, non-official sites can cause river pollution.
Gooddy added, “Collectively, this contribution to overall ammonium concentrations in rivers could be very high. It’s something that really ought to be taken into account when we’re drawing up management plans for floodplains on the margins of towns and cities.”
UK rivers also face a number of threats posed by climate change and industrial agricultural activities. Previous research has warned that intense winter rainfalls, like the one the country experienced last year, might cause more agricultural runoff to be washed into waterways, increasing algae bloom.
Photo: bayerberg via Flickr