‘The special conditions in the geology and surface configuration of the Thames Basin render the water singularly pure for so large a river. The water, as it flows gently down has also the power of becoming oxidized and purified to a considerable degree’Statement by the Revd James Clutterbuck, vicar of Long Wittenham and Thames Conservator, and Professor John Phillips, Reader in Geology at the University of Oxford, in the Report of the Royal Commission appointed to inquire into the Best Means of Preventing the Pollution of Rivers, 1866, D/TC/I1/1/1
Controlling pollution in the Thames became a priority in the Victorian era, and from the beginnings of the Conservancy it was a key function.
The upper Thames had traditionally escaped the pollution experienced in London. There, drinking water from the river killed thousands, and misguided attempts to route more sewage into its reach only worsened the problem. In 1858, the ‘Great Stink’ enveloped the tidal river and an Act was passed to move the foul pipe outlets nearer to the sea.
But the growing use of flushing toilets alongside basic sewer systems meant that many places on the upper river were also discharging untreated waste directly into the river. This was a national problem for safe drinking water and many towns and cities sought powers to improve it. After persistent lobbying, the Government established a Royal Commission on the Pollution of Rivers and this delivered its first report, on the upper Thames, in March 1866. This report concluded that:
‘With regard to the state of the Thames, the evidence shows that all towns and places situated on its banks more or less pollute the river water with sewage. The amount of pollution from un-sewered and un-drained towns, such as Cirencester, Cricklade, and Lechlade, is apparently small, though it is impossible to estimate the amount of liquid which finds its way from cesspits into the river. Towns like Oxford and Reading, although not systematically sewered and drained, add largely to the pollution of the river. Windsor and Eton, which have been more fully sewered and drained, pour out continuously a much larger proportionate volume of sewage’.Report of the Royal Commission appointed to inquire into the Best Means of Preventing the Pollution of Rivers, 1866, D/TC/I1/1/1
The effects of this sewage were described in detail:
The problem was addressed by the Thames Navigation Act and the Thames Purification Act, both passed later the same year. The former, which founded the upper Thames Conservancy, made it illegal for sewage or other pollution to flow directly into the river. The latter gave powers for pollutants to be diverted from the major towns on the non-tidal river: Oxford, Abingdon, Reading and Kingston.
The new Conservators began a regime of inspecting the river and visiting businesses and farms to make sure all the regulations were being complied with. They offered advice on how to improve conditions. If individuals, companies or councils continued to offend they would be taken to court.
Samples of river water were analysed regularly and reported to a new River Purification Committee, who decided on action as necessary.
In response to this report the committee issued the following recommendation for the issue at Deptford:
The inspectors employed by the Conservancy’s River Purification Service were expected to oversee all aspects of pollution prevention. The Conservancy issued instructions for their work. Over time, these expanded to include powers to board launches and other vessels, as well as remove dead animals from the river.
General Instructions to Inspectors and Assistant Inspectors – River Purification Service, 1939, D/TC/D3/2/1 (above and below)
General fines were issued for those found polluting the river and notices were prepared for specific events, including the 1908 Olympics.
Notice against throwing animals into the river, 1905; Pollution notice, 1935; Notice against throwing rubbish into the Thames, Olympic Regatta, 1908, D/TC/G1/6/1
By the 1950s new ways had been found to warn the public against littering:
Despite these efforts, in 1957 the Natural History Museum declared the River Thames to be ‘biologically dead’. Oxygen levels were too low to support life. But this famous declaration applied only to the tidal river in London, over which the Conservancy lost its powers in 1909. The upper river was thriving.
Reports to Parliament in the 1950s suggest that the Thames above London was as healthy as it had ever been. Fish and wildlife were abundant and people continued to swim in the river.
During the 20th century the numbers of instances of pollution in the river remained broadly constant, although the types of pollutants and polluters did change. Untreated sewage reduced but chemical and radioactive waste increased, while modern cruisers and launches offered oil and diesel pollution.