Under The Environment Act 2021 a suite of targets to restore and protect our environment has been developed by Defra. These targets address some of the biggest challenges our environment faces: air and water quality, biodiversity, waste, and resource sustainability. They also aim to improve our woodland and marine environments, and halt and reverse the decline of our natural environment.
Two ambitious targets are directly related to water quality – and in particular, nutrient pollution caused by agricultural practices and wastewater discharges.
Nutrient pollution is a key driver of poor water quality conditions that can impact negatively on natural habitats and wildlife. In some water environments, increased nutrients can encourage the growth of vegetation and algae, which can damage water quality and degrade wildlife habitat. It can be especially detrimental to protected sites that are of critical importance in maintaining UK biodiversity.
Agricultural nutrient pollution
Agricultural practices cause nutrient pollution through the use of fertiliser and other chemicals. Manure from livestock also contributes to the overall load with erosion and sedimentation from over-irrigation, over-tilling, or poor drainage practices upsetting ecosystems as nutrients – predominantly, phosphorus and nitrogen – find their way into rivers and other water bodies. The Environment Act 2021 has set a target to reduce nitrogen, phosphorus and sediment contribution from agriculture in the water environment by at least 40% by 2038 against a 2018 baseline.
Tackling this agricultural pollution aims to improve water quality and biodiversity but it requires changes in agricultural practices. Farmers and landowners will be incentivised to adopt the necessary changes via farming schemes and grants along with advice and partnerships.
Wastewater nutrient pollution
Wastewater entering water bodies can also cause nutrient pollution. The pollution caused by untreated wastewater is tackled by the Storm Overflow Discharge Reduction Plan, which aims to limit the number of Combined Sewer Overflow (CSO) discharges caused by extreme weather events and population growth.
The Environment Act 2021 wants to tackle nutrient pollution caused by treated wastewater with an ambitious reduction target focussed on phosphorus, which is the most common pollutant found when a water body fails to meet Good Status under the Water Environment (Water Framework Directive) Regulations 2017. The target does not include nitrogen as it is believed that agriculture is the source of most nitrogen entering the water environment.
The wastewater target is to reduce phosphorus loadings from treated wastewater by 80% – against a 2020 baseline – by 2038. The reduction will be achieved by creating legal obligations for water companies to remove phosphorous from wastewater received at their treatment works.
Traditional phosphorous removal is an expensive and carbon-intensive process that requires the addition of metal salts – eg ferric sulphate – to chemically precipitate the phosphorous out of solution. The resultant solids are captured by various technologies – removing them from the treated effluent before it is discharged to the environment.
To reduce carbon and costs, water companies aim to optimise their dosing regimes. EMS has a proprietary dosing solution called Ironman that is proven to be capable of reducing ferric dosing by up to 40%. Contact our team for further information.