Green leaves with reflection in water

The Water Framework Directive has prompted water companies to invest in a range of initiatives to improve water quality. The Water Industry Journal looked at a couple of examples.

Pioneering online auction service EnTrade, devised and trialled by Wessex Water in Poole harbour, is helping farmers improve the quality of groundwater on their land.

Farmers can now bid to grow winter cover crops on their fields, reducing the amount of nitrates that can leach into the ground and reach groundwater boreholes.

Wessex Water’s strategy and new markets team came up with EnTrade as an alternative to building a new treatment plant at its sewage treatment works, which would have cost £6 million and have a high carbon impact.

Following two successful trials in Poole, which saw nitrogen outputs significantly reduced, farmers have also been bidding for the cost of growing crops in an EnTrade auction run in partnership with United Utilities.

Cover crops such as barley, oats, oil radish and turnip rape are grown on fields that would otherwise be bare during winter. EnTrade then automatically delivers an estimate of the nitrogen saved, based on the crop type and sowing date.

David Elliott, Wessex Water’s director of strategy and new markets, said: “Through the efforts of farmers and growers, nitrogen levels will dramatically reduce.

“Cover crops work over winter to intercept and reduce the impact of intensive rainfall events, while at the same time accumulating and ‘storing’ nitrates from the soils which would otherwise be leached and reach watercourses.

“We saw it as a win, win, win situation at Poole. Farmers reported improved soil quality and structure, aquatic wildlife was protected and customers’ bills didn’t need to rise to pay for an expensive new treatment plant.”

EnTrade calculates the price of saving, not the implementation cost. The combination of crop type and sowing date means the most successful bids aren’t necessarily the lowest pound-per-hectare bids.

Natural England have contributed to the funding of the auctions, which build on Wessex Water’s previous catchment management work in Poole and elsewhere in its region.

David said: “EnTrade allows us to find the market price for environmental improvements by farmers. This price is then compared with the alternative, asset-based solutions, and we’ve discovered that nitrate reductions contracted via EnTrade can be achieved for a quarter of the cost.

“EnTrade has a proven track record for improving the environment and I am sure this innovative approach has been welcomed by farmers.”