Quest to reduce water pollution caused by nitrate fertilisers
Yorkshire Water has opened a specialist £8m water treatment facility in Hull as part of a wider project to inspire a culture change in agricultural practices amongst East Yorkshire farmers.
The facility - a nitrate removal plant - will reduce nitrate concentration levels in the River Hull that have spiked in recent decades due to intensive agriculture in the Yorkshire Wolds.
Since the 1960s, nitrate-based fertilisers have been commonly used by farmers to improve crop yields. However, over time, they have slowly seeped into and polluted the groundwater that flows in the River Hull, particularly during periods of heavy rain.
The River Hull is the primary source of drinking water for residents in the region, compared to reservoirs which supply most of the drinking water in West Yorkshire.
Andrew Walker, Catchment Strategy Manager at Yorkshire Water, said: “Our new nitrate removal plant will ensure that nitrate concentration levels are reduced and drinking water quality is improved. In addition, we are taking a longer-term approach that involves actively engaging with local farmers to identify sustainable alternatives to nitrate-based fertilisers. This will help to reduce the amount of water becoming contaminated in the first place and decrease the onus having to expensively treat it in years to come.”
A study by the University of Leeds revealed the extent nitrate has contaminated the River Hull. For instance, between 2007–2011, Yorkshire Water was forced to close its Tophill Water Treatment Works for 106 days due to nitrate concentrations exceeding the daily regulatory limit of 50 mg/l NO3.
Another approach to tackle the fertiliser problem has been to promote Catchment Sensitive Farming, which is a sustainable farming ethos promoted by The Environment Agency, Defra, Natural England and Yorkshire Water. This approach involves providing advice and workshops for farmers on how they can help protect rivers and groundwater from pollution.
Rachel Webster, Natural England’s Catchment Sensitive Farming Officer - East Riding of Yorkshire, explained: “We understand that there is increasing pressure on farmers to increase food production and as such use fertilisers to boost yields. However, there are environmentally friendly alternatives that protect the River Hull’s water quality.”
Rachel added: “One alternative to nitrate-based fertilisers are to plant cover crops. These naturally absorb nitrogen from the atmosphere, acting as an environmentally friendly substitute to invasive chemical fertilisers. This technique, where appropriate, can also improve soil nutrient quality which in turn helps crops to grow and yields to increase.”
Yorkshire Water’s nitrate water treatment facility was designed and constructed by Amey and is one of the largest plants of its kind in the UK. It is based at the company’s Tophill Water Treatment works in Driffield, which is also home to a nature reserve declared as a nationally important site for bird life.