We are hoping to launch this grant in mid 2026. Once launched we expect the application process – from application to the installation and commissioning of the new tank will take 6 months.
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The Solent is internationally important for its wildlife, over many years the Partnership for South Hampshire has led on initiatives to improve the environmental, cultural and economic performance of Hampshire and one area is reducing nutrients that enter the tributary rivers of the Solent – River Itchen, Test, Meon, Hamble and the Sowley stream. In 2024, Councils across Hampshire joined forces and received funding from central government to create the Solent Mitigation Partnership (SMP) to continue to provide much needed support in the area to further reduce nutrients.
The SMP is launching an initiative aimed at upgrading privately owned residential septic tanks to reduce nutrient-rich wastewater entering watercourses and, in turn, enhance the health of our aquatic ecosystems.
Septic tanks are commonly used to separate liquid and solid toilet and sink waste in areas that cannot be connected to a mains sewage treatment plan. They are designed to settle and retain the waste solids produced from a home. This is usually a tank situated in a properties garden that has several chambers within it, and uses pipes or baffles to settled liquid which then drains away through soakaway or drainage field. The drainage field is designed to treat the waste effluent by the action of naturally occurring bacteria.
During their lifespan they can inadvertently release nutrient rich wastewater into rivers, contributing to pollution. The resulting high nutrient levels lead to algal blooms in estuaries, obstructing light and causing oxygen depletion in waterways. This has detrimental effects on the entire river ecosystem, impacting crucial microhabitats for fish and insects. To counteract this issue, a new law mandates the upgrade of old septic tanks discharging into surface water.
This guidance provides advise on a Council funded grant to homeowners in specified areas of the Itchen catchment for upgrading their sewage systems. The initiative promotes the replacement of septic tanks with more efficient package treatment plants, tailored to each property’s needs. These upgraded systems not only separate solids and liquids but also biologically treat effluent removing nutrients for safe discharge into watercourses. What to expect from the scheme – a grant to upgrade your septic tank to a Package Treatment Plant.
The Solent Mitigation Partnership will supply a grant to upgrade your septic tank. It needs to be over 10 years old or clearly not providing treatment of sewage within the manufacture specifications approach. This grant procedure has been designed with local authorities to reduce the process for you to perform the upgrade.
Septic tanks usually have a lifespan of about 20 to 30 years before they need replacing. The cost of replacing a tank can range between £15k and £30k with some installations in remote or hard to access areas costing even more. You will benefit from a new modern treatment tank which not only processes your household sewage but also improves the ground water discharge making it into the local river.
Our process offers the freedom for you to choose the installer of your tank. Unlike other grant schemes we do not select the installer for you. You create a contractual relationship with the installer you have chosen to work with, and we pay them for the install.
The SMP is offering up to £30k, most of this will be for your installer to perform the upgrade. We will pay for the feasibility study and quote, the equipment and installation and the first service of the tank. The remaining will pay for items like planning application, hydrological surveys or water testing if they are required.
In return for the grant, you enter into a statutory legal agreement with the SMP which transfers the right of the nutrient mitigation created by the upgrade. This is a long-term commitment of 100 years.
Whether something is “right for you” depends entirely on your individual circumstances. Generally, this scheme is a great way to upgrade your septic tank free of charge. Key areas for you to consider is the long-term commitment you will be entering into and how that impacts on future decisions about your property, a minor consideration is the overall goal of the scheme which is designed to enable house builders to develop new housing in your town or local area.
We will roll out in phases with the first launching in mid 2026 and is designed to test the grant approach. The phased areas are: