The government has published a list of over 140 wastewater treatment works legally required to be upgraded to stringent nutrient removal limits.

The requirement to deliver nutrient neutrality will enable the construction of thousands of homes and improve aquatic ecosystems.

Water companies have a duty to ensure wastewater treatment works serving a population equivalent over 2,000 discharging into designated catchments meet specified nutrient removal standards.

The nutrient pollution standards specified (10 mg per litre for nitrogen and 0.25 mg per litre for phosphorus) align with current Technically Achievable Limits. This is the most stringent limit the Environment Agency will normally set in a permit to reduce a certain pollutant from wastewater using currently available technology.

Defra has also updated the list of sensitive catchment areas and effects, including an updated map. The areas are designated as sensitive areas for phosphorus or nitrogen under the Water Industry Act 1991.