| Pollution The water in a healthy chalk stream should be 'gin clear' as it is when it emerges from the aquifer at its source. The growing pressures from people and farming have polluted the river. The human population in the Kennet increased from about 55,000 in 1931 to 175,000 in 1991. Numbers of farm animals have increased substantially, while the area under cereal crops has nearly trebled. As a result of these changes, annual phosphorus input to the river has increased from 94 to 247 tonnes in 1991. Half of this came from sewage and a fifth each from livestock (mainly cattle) and arable land. At the same time, nitrogen inputs have risen from 1,720 tonnes to 4,050 tonnes per year, two-thirds from agriculture and a tenth from sewage. (Date source: The State of England's Chalk Rivers, published by The Environment Agency and English Nature, 2004.) Phosphate removal at Sewage Treatment Works After sustained campaigning by ARK, Thames Water installed phosphate removal at the Marlborough Sewage Treatment Works in 1997. This reduced the phosphorus content of the effluent by 75%. Phosphate removal plants have recently been commissioned at the Fyfield and Ramsbury Sewage Treatment Works. ARK will continue to investigate the effect this has on phosphate levels. Diffuse pollution from agriculture As agriculture has become more intensive, pesticides, fertilizers, animal faeces and soil are washed off the land into the river. The impact of these diffuse pollution sources can be reduced by good land management. Land management projects
ARK is working with farmers and landowners to encourage 'buffer strips' of land to be left along the banks of the Kennet to minimize agricultural pollution. These strips of land will absorb some of polluted run-off before it reaches the river, and will prevent quantities of soil and silt being washed into the river. Rubbish and rubble is carelessly thrown into the river. Litter is a particular problem in Marlborough town centre. ARK regularly organise rubbish clearing to combat this problem. If you'd like to help, send us an email. | 
