Diffuse pollution is a major and increasing problem, says report

The magnitude and frequency of diffuse pollution is forever increasing in relation to pollution from point sources, but until now statutory control has been ‘piecemeal’ said David Arnold-Forster, Chief Executive of the governmental agency, English Nature, welcoming the release of Diffuse Pollution Impacts: The Environmental and Economic Impacts of Diffuse Pollution in the UK.It is hoped that the report, which contains a chapter on each pollutant, its sources and environmental and economic impacts, will generate debate and be a focus for concerted effort to tackle the problem and a copy will be sent to the Secretary of State for the Environment, Michael Meacher.

The report is the result of two years of study by the Chartered Institution of Water and Environmental Management and the International Water Association, and was released on 16 October with a day of talks and workshops on diffuse pollution at the Institute of Physics in Central London.

“Our Sites of Special Scientific Interest (SSSIs) are impacted adversely in many ways by diffuse pollution, which is one of the greatest threats to wildlife in England and thethe greatest threat to aquatic life,” Arnold-Forster said.

Diffuse pollution accounts for 40-60% of pollution from phosphorous and 80% from nitrogen, the report says. Other major sources of diffuse pollution are particulate, heavy metals, hydrocarbons, pathogens and pesticides.

The species and habitats listed as being under threat from diffuse pollution are; rivers, lakes, salmon, lamprey and wildfowl. It also presents a public health risk in the form of polluting drinking water. Arnold-Forster cited two particularly worrying cases of diffuse pollution in the UK; Run-off from potato farms, combined with a depletion of buffer strips, has caused the River Wye to suffer from siltation and pollution from fertilisers, and salmon and trout populations are facing severe depletion in the River Esk because of siltation caused by erosion of the North York moors and pollution from sheep farms.

The causes of diffuse pollution in rural and urban areas vary greatly, the report says. The principle causes of rural diffuse pollution are:

• inorganic inputs from farms, including fertiliser, pesticide and herbicide, mainly entering water systems as run off ;
• incorrect ploughing techniques allowing run-off, where farmland on a slope is ploughed vertically instead of contour ploughing;
• the removal of buffer strips and boundaries between farmland and rivers;
• reduced leys and use of rotations;
• reduced organic soil content;
• excess organic application e.g. slurry;
• high density outdoor pigs and overstocking of livestock.

“We need to show the importance of trying to educate the farming community in the older skills,” commented Arnold-Forster, adding that European regulation was essential to tackle issues, such as overstocking.

Construction discharges, lane drainage and urban and industrial run-off were cited as the main causes of diffuse pollution in urban areas. Dog faeces was cited as just one example of a major, yet often overlooked, cause of urban diffuse pollution, as around 900 tonnes is deposited on UK streets daily.

According to Arnold-Forster, “carefully monitored pilot schemes in areas of great risk are essential” to combat all forms of diffuse pollution . Funds should be concentrated where the effects of diffuse pollution are felt most acutely, such as on SSSIs, of which 30% are in an “unfavourable condition”, and control programmes must be drawn up, despite a lack of certainty over some of their effects. “Of the many actions impacting negatively on the aquatic environment, diffuse pollution is the most difficult to control,” Arnold-Forster added.

Ten areas were action needs to be taken were put forward to combat the problem:

• awareness and education, which is currently ignored, and where individuals, such as dog owners, do not realise the damage caused by diffuse pollution;
• collective action, for example getting fishing clubs to co-operate on improving fish populations;
• regulation;
• licencing;
• cross-compliance;
• subsidies and environmental schemes;
• taxes and tax allowances
• planning obligations, where big developers should give a pay-back for urban schemes;
• clean technology;
• ‘invest to save’ schemes.

“What we need is a catalyst to combat diffuse pollution, which is external funding,” Arnold-Forster added

At present, the recently agreed EU legislation, the Water Framework Directive is the best opportunity for controlling the problem, but will require new approaches for improved management of diffuse sources, Arnold-Forster said. “We should not let the Directive become a piece of obscure legislation”, said William Halcrow, Director of the Scottish Environmental Protection Agency’s (SEPA) East Region, adding that much diffuse pollution comes from pipes, which are regulated.

Fifty-nine percent of Scotland’s lower quality rivers and 83% of its lochs suffer from the effects of diffuse pollution, Halcrow said. High-quality water is also very prone to diffuse pollution , where the effect takes ‘generations’ to recover, he said.

A copy of the report can be ordered at a cost of £50 by calling 01787 249292, or by e-mailing claire@lavenhamgroup.co.uk