The Institution’s ‘Catchment Management in the Water Industry’ report says that while the EU Water Framework Directive has improved natural water quality, particularly in UK rivers, this has only been achieved through energy and chemical intensive treatments which are hugely damaging to the environment.
Dr Jenifer Baxter, head of energy and environment at the IMechE, said: “EU water regulation is aimed at improving the environment but the excessively stringent, universal rules have led to practices which do the very opposite. Currently, the negative side-effects of this directive to the environment may outweigh the benefits.
“A ‘one size fits all’ single European vision to improve water quality is neither effective, efficient nor appropriate. We need an urgent review to enable a more holistic approach to water management.”
According to the report, current legislation is overly stringent and improvements in UK water quality have only been achieved through the construction of high energy intensive treatment processes at sewage treatment works necessary to meet the tightened effluent consent levels. This is said to be costing UK water companies up to £9million a year on electricity to run 300 blowers for activated sludge plants
Industry estimates suggest that 1% of all of the UK’s electricity is consumed by compressors used for the aeration of wastewater at the nation’s sewage treatment works. While Ofwat data from 2010 stated that greenhouse gas emissions from the operational side of the water industry are approximately 0.7% of the total UK emissions.
Another area of waste water treatment that has increased in importance is the requirement to control levels of nitrogen and phosphorus. Levels of both have increased in raw sewage due to the increasing use of detergents and fertilisers. Although natural processes do remove both nitrate and phosphate in most cases, the levels of reduction required cannot be achieved through natural processes alone and it is necessary to use chemicals, typically ferric chloride, ferrous sulphate or aluminium salts. The greenhouse gas emissions associated with the use of these chemicals is significant and continuity of supply is becoming a major concern.
The report suggests that the effective catchment management called for by Ofwat will not happen without structural reform, and that the water industry is too complex to achieve these goals. It states that a key aspect of Ofwat’s strategy should be that Catchment Management Teams should be given powers to make binding decisions, including the management of finance to implement those decisions.
