Posted on behalf of Everleigh Parish Council
Wiltshire Council has provided an update on the Revamp Your Tank scheme, a septic tank upgrade programme delivered in partnership with Wessex Rivers Trust.
The scheme is designed to help improve water quality in the River Avon (Hampshire) catchment by supporting the replacement of older domestic sewage systems with newer, more efficient tanks that reduce the amount of harmful nutrients entering the river.
The programme is funded through a Government grant intended to support nutrient mitigation projects. These projects help offset the environmental impact of new housing developments within sensitive river catchments and ensure that development remains nutrient neutral, in line with guidance from Natural England, the Environment Agency, planning regulations and building control requirements.
How the Scheme Works
The initial Government funding for the programme came through the Local Nutrient Mitigation Fund (LNMF). This funding helped establish replacement tank projects and other initiatives aimed at reducing nutrient pollution.
To maintain the scheme, the fund must be replenished through the sale of nutrient credits. These credits are generated when new tanks perform better than the systems they replace, reducing the amount of nutrients entering the watercourse.
Developers working on new housing projects in the catchment can purchase these nutrient credits to mitigate the environmental impact of their developments. Income from these sales is then used to support further tank replacement projects.
Current Update
Wiltshire Council has noted that while the scheme has always reserved the right not to proceed with projects before a customer contract is signed, some applicants have experienced delays and frustration with the pace of implementation.
The timing and location of replacement tank installations are largely influenced by demand for nutrient credits from developers, as this is what allows the scheme’s funding to be replenished.
To help improve transparency, the council has updated the scheme website and expanded the Frequently Asked Questions to provide clearer information for applicants.
Legislative Changes
Recent changes introduced by the Planning and Infrastructure Act 2025 may also affect the nutrient mitigation market. Combined with a slowing demand from developers, this could further impact the pace at which replacement tanks are delivered under the scheme.
Further Information
Full details of the scheme and updated guidance can be viewed in the official document below.
