New duties for water companies to upgrade wastewater treatment works by 2030 have been proposed as part of twin-track approach to dealing with nutrient pollution in protected catchments.
The government’s proposals are intended to allow developers to build homes on sites previously deemed unsuitable due to the impact on wildlife habitats in areas that already have high levels of phosphorous and nitrogen in waterways.
Phosphorous enters the water system from human and animal waste, industrial effluents and fertiliser runoff, whilst nitrogen is associated with agricultural processes and is also found in urea.
The government said it intends to place a duty on companies in England to upgrade treatment works in nutrient neutrality areas to the “highest achievable technological levels”.
The necessary upgrades will be set out in an amendment to the Levelling Up and Regeneration Bill. Suggested improvements include adding metal salts to wastewater and nature-based solutions such as reedbeds and wetlands.
The government will work with the sector to identify where the delivery of improvements to water treatment works can be accelerated and complement upgrades brought in under the Environment Act to reduce the risk of harm from combined sewer overflows (CSOs).
The Environmental Audit Committee (EAC) said it broadly supports the proposals.
However the committee’s chair, Philip Dunne, pointed out the need to address agriculture as the source of excess pollutants: “As we made clear in our report considering water quality in rivers, farming also has a part to play in reducing excess nutrients flowing into our rivers from animal waste.
“We repeat our recommendation that a periodic appraisal is undertaken of catchment-wide nutrient flows across each major river catchment in England to understand better the state of play.”
Despite this, Dunne called the proposals “sensible and pragmatic” measures to improve the health of waterways.
“There is no magic wand which can instantly reverse decades of decline in water quality, but step-by-step action is being taken to make sure water and sewerage companies are held to account and that the chemical cocktail which can course through our rivers is addressed.”
The second part of the twin-track approach jointly proposed the Department for Food, Environment and Rural Affairs (Defra) and the Department for Levelling Up, Housing and Communities (DLUHC) is a new Nutrient Mitigation Scheme that allows developers to buy “nutrient credits” to discharge their requirements to provide nutrient mitigation in polluted areas.
Presently, planning authorities can only approve a project if they are satisfied it will have no negative effect on protected sites. Defra and DLUHC will award authorities £100,000 of funding each to pump prime the creation of the mechanism.
Natural England will accredit mitigation delivered through the scheme and has begun working with 74 planning authorities to help developers apply for credits.
Government cited “complex and bureaucratic EU-derived domestic legislation and case law” as a reason preventing homebuilding in areas with high nutrient levels.
Defra also said increased funding for the Environment Agency would allow it to inspect “at least” 4,000 farms annually to 2023. The EA was previously criticised for its low rate of inspections that equated to once in 200 years. Across the UK there are around 192,000 farms.
Natural England chair Tony Juniper said: “The duty on water companies and the Nutrient Mitigation Scheme mark significant steps forward, and will help join up the various approaches to improving water quality and bring about multiple other benefits.”