Septic tank credits scheme to unlock housing in nutrient neutrality areas

(by Karma Loveday)

The National Rivers Consortium (NRC) — a partnership of environmental specialists, engineers and construction professionals dedicated to improving water quality through nature-based solutions — has launched a pioneering initiative to unlock thousands of delayed housing developments while restoring the health of the nation’s waterways.

Under a first-of-its-kind scheme, developers active in areas designated for nutrient neutrality can purchase verified phosphorus and nitrogen credits, generated through septic tank upgrades which are provided for free to households in the area. The upgrades remove phosphorus and nitrogen before they reach waterways. The resulting nutrient savings are verified, converted into credits and made available to developers.

The scheme uses a Conservation Covenant and, according to NRC, has been proven as a practical and scientifically robust route to meeting nutrient neutrality rules across the UK.

The scheme is backed by RSK Biocensus, the habitat restoration and rewilding arm of the RSK Group, which became a Responsible Body under the Environment Act 2021, in early 2024. RSK Biocensus is authorised to administer the Conservation Covenant, monitor septic tank compliance and ensure that all nutrient offsetting activity delivers genuine and lasting environmental gain. This saves each Local Planning Authority from having to take these roles themselves.

The scheme can be accessed via a Developer Portal, which includes an interactive catchment map, enabling developers to quickly confirm whether a site falls within a nutrient-impacted catchment. Construction professionals can also see budget costs for required credits upfront, and access guidance on nutrient neutrality requirements, credit allocation and engagement with NRC.