EU rules set limits on pesticide and nitrate levels in drinking water. Water companies have had to make substantial investments in the past to remove these chemicals by improving water treatment or, in the case of nitrates, blending water from different sources.
But more investment is now needed to cope with the continuing deterioration in water quality. In draft plans for the industry's fourth asset management planning round (AMP4), water companies have put forward a total of 94 schemes to reduce nitrates and 54 to reduce pesticides.
In March, some 72 nitrate and 20 pesticide schemes gained outline approval from Environment Secretary Margaret Beckett in her advice to water regulator Ofwat on what should be included in companies' investment plans (ENDS Report 350, pp 46-47 ).
Anglian, Severn Trent and Wessex each have major programmes for nitrate removal or blending (see table). New pesticide removal schemes tend to be in the north and west because many works in the south and east are already equipped.
Water UK's policy advisor Jacob Tompkins estimates the capital cost of these schemes to be £300-400 million for nitrate and £30-50 million for pesticides. Running costs would add a further £6 million per year.
Mr Tompkins calls for measures to protect groundwaters and rivers used for water supply. "We still don't have integrated catchment management in this country.... I have just come back from Germany where they are spending as much on catchment management as we spend on end-of-pipe treatment."
European water experts recently met in Oldenburg, northern Germany, to discuss an ongoing EU-funded project on water quality and drinking water issues known as Water4All. The project has provided a forum for Member States to share experiences and approaches to addressing diffuse pollution issues, particularly from farming.1Bob Harris, the Environment Agency's head of air, land and water science, commented: "The project has opened my eyes to the fact that we are falling way behind on integrated catchment management solutions. Countries like Denmark, the Netherlands and Germany are addressing water quality problems with a combination of measures which give a win-win-win situation."
The local authority in Aalborg, Denmark, has been purchasing farmland to establish forest and permanent grassland to protect a chalk drinking water aquifer from nitrate pollution, as well as creating recreational facilities and wildlife reserves.
In Lower Saxony, abstraction fees are being used by a local authority to fund catchment protection measures such as an advisory service for farmers and to subsidise land purchases by water companies in pollution-sensitive areas.
In the Netherlands, Drenthe local authority and the water board have created a marshland from farmland to reduce nitrate levels in river water, replenish a shallow aquifer with low nitrate water for public supply, create wildlife habitats and provide recreational facilities.
The UK's contribution to the project will be a modelling exercise in the river Slea catchment in Lincolnshire. The model will determine how much agricultural land would have to change to less intensive use to protect the limestone aquifer and river quality.
The Government is due to consult shortly on measures to reduce diffuse pollution from farms. Recent research strongly suggests that the existing measures to curb nitrate pollution from farming are insufficient to reverse the rising levels of nitrate (ENDS Report 343, p 8 ).
However, it is unlikely that the Government will envisage the major changes in land use seen in the schemes put into practice on the continent. Indeed, these schemes would be difficult to reconcile with the UK pattern of large privately-owned water companies which are divorced from local government.
Mr Harris believes that the solution to the current UK nitrate pollution problems are a re-negotiation of the 50mg/l EU limit on nitrate in drinking water or "quite radical land-use change, not just tinkering with best [agricultural] practice". Neither would be simple to achieve.
Mr Tompkins and Mr Harris agree that the UK's reliance on end-of-pipe solutions like nitrate or pesticide removal are out of step with Europe and not compatible with the water framework Directive.
Article 7 of the Directive requires Member States to protect drinking water sources "in order to reduce the level of purification treatment required". Article 4 also requires States to "reverse any significant and sustained upward trend" in groundwater pollutants "in order to progressively reduce pollution".
In order to obey the EU Directives, the UK will have to continue to pay for drinking water treatment to remove diffuse pollutants and also fund catchment protection measures to provide a long term and sustainable solution.
"The schemes proposed now do not solve the pollution problems," Mr Tompkins observed. "There are many sources on the edge. Catchment management now will stop them from being an issue next time around."