Discharges into the sea and watercourses have caused eutrophication which in turn causes algae to form, starving water and sediments of oxygen, killing off aquatic species and forming a barrier to feeding birds. Nitrates come from a number of sources, mainly agriculture and wastewater treatment discharges but also from soil disturbed by construction. Natural England’s decision in 2019 to require all new developments involving overnight stays to be nutrient neutral had a significant impact on the housebuilding industry.
Demonstrating nitrate neutrality involves calculating the nitrogen load for a proposed development and offsetting this in some way. Many planning authorities do not yet have offsetting schemes in place, whilst others that do cannot guarantee spare capacity for all planned developments.
Offsetting schemes typically involve taking land out of agricultural production and planting woodland or wetland habitats. There are also examples of successful on-farm schemes which work alongside productive farming activities. Both options provide nitrate credits that can be purchased by developers to enable development to proceed. This presents an immediate opportunity for farmers and landowners to receive income from developers to enable their projects to go ahead.
Offsetting schemes can also be used in Biodiversity Net Gain (BNG) calculations. BNG is to be made mandatory for all new developments in England and requires schemes to leave biodiversity in a better state than before.