The European Commission issued its proposal for a Directive setting limits for dangerous substances in water last summer (ENDS Report 379, p 48 ). The proposals, which take the form of a daughter Directive to the water framework Directive, require discharges of "priority substances" to be progressively reduced and discharges of "priority hazardous substances" to be phased out.
They also put forward environmental quality standards (EQSs) for the substances, expressed as annual average values and maximum admissible concentrations.
DEFRA is seeking views on whether the proposals would be workable and would protect waters from pollution, and what costs would be associated with meeting them.
The consultation sets out options that include doing nothing - risking infraction penalties from the European Court of Justice- or implementing the proposals to varying degrees. At the bottom end of the scale is end-of-pipe treatment for point source discharges - which might not be sufficient in some cases. At the other end is end-of-pipe treatment plus controls on products and processes responsible for discharges or emissions.
A cost-benefit analysis of the proposals lists reduced human exposure to hazardous compounds and reduced water treatment costs on the positive side. But the costs for some sectors would be substantial and many cannot be evaluated fully until the measures required are outlined in river basin management plans.
The costs are based on consultations with industry sectors and come with a warning about the high degree of uncertainty.
The study predicts costs of "around £1 billion" for the water industry, mainly because of the need to reduce lead and nickel discharges. Some 10% of sewage works will have to fit additional treatment and the result will be an increase in sludge production - incurring an extra £1.9 million per year in disposal fees.
Other industries likely to be affected include chemicals, pharmaceuticals, paper making, metal finishing and textiles. The total costs would be up to £3.7 million per year (see table).
However, the measures required may be highly specific and the study considers four water pollution case studies:
- Pesticide run-off: The list of priority hazardous substances includes five pesticides which can still be used in the UK: endosulfan, chlorpyrifos, diuron, isoproturon and trifluralin. Previous studies suggest that switching to alternatives may incur extensive costs, for example, up to £14.2 million per year to achieve a 70% reduction. Total replacement might be more expensive and farmers would shoulder most of the cost.
- Air emissions: EQSs for benzene, fluoranthene, anthracene, polyaromatic hydrocarbons, cadmium and mercury could be breached by air emissions. Options for reducing emissions include technical measures such as catalysts or economic measures to discourage emissions, for example, from vehicles.
- Sediments: Contaminated sediments in places such as harbours could cause breaches of the EQS for tributyl tin, which has been used to protect boat hulls. Many options exist for reducing levels, but costs vary from about £2 million to more than £1 billion annually where dredging is needed.
- Diffuse metal inputs: Industrial processes, product use, agriculture, mining and waste disposal are all likely to contribute to diffuse metal inputs to water. The study concludes that the costs of reducing such diverse sources are difficult to predict, but the Environment Agency is preparing pollution reduction plans for nickel, cadmium and lead that should include cost-effective measures.