Ongoing uncertainty over nutrient neutrality is muddying the waters, says Karen Allso of Ramboll
Expansion of our urban areas, for example by increasing the number of residential dwellings, can result in a greater load of nutrients being received at wastewater treatment works and subsequently results in an increase in the nutrient load discharged from those treatment works to surface water, including sensitive waterbodies that are ecologically designated sites.
A number of ecologically designated sites have been shown to be impacted by high and increasing inputs of nutrients (principally nitrate and phosphates) within their catchments, which can lead to eutrophication and damage to ecological receptors.
The catchments of these impacted sites have been identified (eg by Natural England and Natural Resources Wales) as “affected catchments” where nutrient neutrality must be achieved due to current exceedances of nutrient threshold limits.
What are the current nutrient neutrality guidelines?
Under the UK’s Habitats Regulations, competent authorities (eg local planning authorities) have an obligation to consider the impact of additional nutrients arising from new developments on ecologically designated sites. They must consult Natural England or their national equivalents, which are responsible for ensuring compliance with the regulations.
Within affected catchments, it is therefore necessary, at present, for housebuilders to demonstrate suitable mitigation of nutrient impacts, either by direct reduction of nutrient loads on or off-site, or purchase of “nutrient credits” used to fund strategic mitigation solutions.
On 13 September this year, the Levelling-up Regeneration Bill was amended to remove requirements to consider and mitigate for nutrient neutrality from housebuilders and this was put forward to the House of Lords, with the reforms being intended to provide certainty that developments could proceed. The bill instead proposed a strategic package of measures that were identified to broadly reduce nutrient input to waterbodies at a catchment scale.
The measures included committing funding to accomplish several objectives, including expanding existing nutrient mitigation schemes, utilising nutrient management to improve farming practices and encouraging uptake by introducing payment premiums.
Further measures include accelerating efforts to recover habitat sites through Protected Sites Strategies, introducing targets for improvements to agricultural practices, investing in improving slurry infrastructure and consulting on modernising fertiliser standards.
Concerns were raised over a catchment-scale management approach
Though a catchment-scale management approach may be theoretically practical, a number of the strategic measures detailed by the government were either already in existence or would have been implemented irrespective of the proposed reforms, with little evidence to support any material improvements achieved so far.
Concerns were raised by various government agencies and organisations, such as Greenpeace, wildlife trusts and the UK’s environmental oversight body, the Office for Environmental Protection (OEP), about this approach. The OEP warned that the proposed changes would “reduce the level of environmental protection provided for in law and amount to a regression”.
While the suggested reforms were greeted positively by housebuilders, as they would have alleviated the financial burden and potential project complexities from them, the reforms did not receive sufficient support from the House of Lords, and thus were struck out of the Levelling-up & Regeneration Bill.
Notably, the House of Lords was uncertain as to how the proposed changes would align with the requirements of the Habitats Regulations and thus provide effective mitigation. into environmental land management schemes.
A new government bill is due to be announced
The government’s levelling up and housing secretary has recently announced that it is planning to table new legislation to “unblock homes currently held up by nutrient neutrality rules” to be delivered under a new bill.
We wait to see how the government will demonstrate within this new bill that a scientific and evidence-based approach is being taken to deliver satisfactory standards and criteria to meet the requirements of the Habitats Regulations. Without this, competent authorities would lack the safeguards to ensure no additional nutrients would be added to affected catchments.
For now, the existing requirements and regulations remain in place, with an indeterminate date by which the government may propose further legislation, and that will undoubtedly be subject to challenge in the courts. This results in uncertainty, financial and programming risks, particularly for housebuilders, local planning authorities and those involved in nutrient credit transactions.
During this period of uncertainty, developers will still need assistance in quantifying nutrient loads associated with their portfolios in some of the most sensitive catchments in the UK. That includes the Solent catchment, which was the first affected catchment to be identified by Natural England.
The suitability of potential mitigation options will also need to be appraised, along with how to sustainably approach to providing a built environment that meets the needs of a society facing climate and biodiversity challenges, while minimising regulatory, cost and construction programme risk.
Karen Allso
Management consultant
Ramboll
Tel: +44 20 7631 5291
