Septic Tank Upgrade Grant
Eligible homeowners in parts of Bishop’s Sutton could receive up to £30,000 from the Solent Mitigation Partnership to replace an older septic tank with a package treatment plant. Choose UKDP to manage the survey, installation and sign-off.
What is the SMP Septic Tank Upgrade Grant?
The Solent Householder Septic Tank Upgrade Grant is a government-funded scheme delivered by the Solent Mitigation Partnership (SMP), which brings together 16 local authorities.
It helps eligible homeowners replace older septic tanks with modern package treatment plants. These systems reduce the nutrients entering the River Itchen and the wider Solent, helping to protect sensitive habitats.
In return for the grant, the nutrient credits created by the upgrade transfer to the SMP. The homeowner must also sign a legal agreement covering the system’s future maintenance.
Choose UKDP and we’ll manage the technical work from start to finish, from surveying your existing system and designing its replacement to installation, commissioning and sign-off. We’ll also provide the report and quotation that the SMP needs to assess your application and confirm your grant award.
Is the SMP Grant for You?
The current phase is limited to qualifying residential properties in designated parts of Bishop’s Sutton along the River Itchen.
You may be eligible if:
- Your property is within the approved upgrade area and water catchment.
- You own the residential property.
- Your existing septic tank is more than 10 years old.
- Its discharge complies with an Environment Agency permit or the General Binding Rules.
Properties in Council Tax bands A to D will be prioritised. Meeting these conditions does not guarantee funding, as the SMP verifies every application and makes the final decision.
Unsure where your property or septic tank stands? We can help you understand the criteria and prepare the technical information required.
What Could the SMP Grant Cover?
Successful applicants can receive up to £30,000. Up to £28,000 may be used for the installation work, including VAT, while £2,000 is reserved for legal and administrative costs.
Subject to approval, the grant can cover:
- The feasibility survey and technical assessment
- A qualifying package treatment plant
- Installation and commissioning
- A percolation test, where required
- First-year servicing
- Building Regulations approval
- An Environment Agency permit, where required
- Planning application fees, where required
- Title searches, legal costs and countersigning costs
You remain responsible for costs above the approved award, optional or ancillary work, external legal advice, electricity, servicing after the first year and eventual system replacement.
Why Choose UKDP for Your SMP Septic Tank Upgrade?
As a registered SMP installer, we combine specialist off-mains drainage knowledge with the technical reporting, project management and documentation your upgrade requires.
Registered with the SMP
UKDP appears on the SMP installer list. We can complete the site assessment, technical report and quotation required for the grant decision.
15 to 20-year structural warranty
Your package treatment plant will include a manufacturer’s structural warranty of 15 to 20 years, depending on the selected system.
Three-year workmanship guarantee
Every UKDP SMP installation includes our three-year workmanship guarantee, at no additional cost to you.
Substantial business cover
UKDP maintains Professional Indemnity insurance of £2 million, reflecting the responsibility we take for our technical advice.
Supporting the Solent
We pledge a contribution from every UKDP SMP installation to Hampshire & Isle of Wight Wildlife Trust, supporting its work across local rivers, wetlands and marine habitats.
Off-mains expertise since 2009
We assess and install septic tanks, package treatment plants and connected drainage systems, including projects in nutrient-sensitive catchments.
How Your SMP Grant Upgrade Works, Step by Step
The complete process typically takes around six months. The SMP manages eligibility and funding decisions, while UKDP handles the technical assessment, installation and handover.
Submit your application
Complete the SMP application form, select UKDP as your preferred installer and receive your application reference number.
Eligibility is checked
The SMP reviews your location, property type, ownership, Council Tax band, catchment and the age of your septic tank.
We assess the site
We survey the existing system, design a suitable upgrade and submit our technical report and quotation to the SMP.
The SMP decides
Applications supported by completed reports and quotations are assessed monthly. The SMP confirms whether funding is awarded and the approved amount.
Sign the agreements
If approved, you sign the Grant Finance Agreement, Unilateral Undertaking and works contract. Your mortgage lender may need to countersign.
We complete the upgrade
We agree the schedule, install and commission your package treatment plant, then provide the required completion documents.
First-year servicing
We complete the servicing included in the grant. After the first year, you arrange and fund the system’s ongoing annual maintenance.
What Customers Say
UKDP have, from my first contact with them, been very helpful, informative and re-assuring even when all hope seemed lost for a favourable outcome. Their in-depth knowledge and sheer determination made our claim possible where I feel sure most companies would have given up!
Thank you all so very much for all your work on my behalf. There is no way it was going to get done without your input. I would recommend you to anyone with similar problems. It's such a relief to have it done. Thanks again.
I would like to thank you regarding the claim you handled for me regarding my Septic Tank. You kept me fully informed of progress with my Insurance Company. The replacement tank was installed last month. I am so relieved that the work is now complete. I would be grateful if you could also pass on my thanks to Kevin. I think he attended three times and he was always very professional and reassuring.
Our SMP Septic Tank Upgrade Work
What the Unilateral Undertaking Means for Your Property
To receive the grant, you must sign a Unilateral Undertaking: a legal agreement that remains attached to the property. It requires you and future owners to:
- Maintain and service the new treatment plant.
- Keep the agreement in place for 100 years.
- Ensure any future replacement provides equal or better environmental performance.
- Transfer the nutrient credits created by the upgrade to the SMP.
If the property is mortgaged, your lender may need to countersign the agreement. You must also disclose it to future buyers if you sell.
UKDP will provide the installation and completion documents, but the legal agreement is between you and the SMP. Any independent legal advice you request is not covered by the grant.
Your SMP Upgrade Completion Pack
Once your new package treatment plant has been installed and commissioned, we provide a completion pack containing the key guarantees, certificates and maintenance information for your records.
This includes:
- The manufacturer’s structural warranty, lasting 15 to 20 years depending on the system installed.
- UKDP’s three-year workmanship guarantee.
- The groundworks guarantee.
- Electrical certification.
- The Building Regulations certificate.
- Your servicing schedule and maintenance guidance.
Keep these documents with your property records. They provide evidence of the completed installation, explain how the system should be maintained and may be needed by your mortgage lender or a future buyer.
Septic Tank Support Beyond the Grant
The SMP grant is one route to an upgrade. We also inspect, empty, repair and replace septic tank systems for properties within and outside the current grant area.
Installation
Planning a new or replacement system? We assess the property, ground conditions, drainage arrangement and applicable requirements before recommending a suitable solution.
Learn moreRepairs
We investigate the tank and connected drainage to identify the cause of the problem before advising whether repair or replacement is appropriate.
Learn moreInspection
A detailed assessment of the tank, pipework, outlet and discharge arrangement, followed by clear findings, compliance advice and recommended next steps.
Learn moreEmptying
We can help arrange routine septic tank emptying through trusted local partners. The appropriate schedule depends on the tank, household usage and sludge levels.
Learn moreRelated Blogs
Septic Tank Leaking Above Ground
Learn what surface leaks and soggy ground may indicate, why emptying comes first and when a detailed inspection is needed.
Read article
A Successful Sewage Treatment Plant Installation in Cheshire
Follow a 20 population treatment plant installation serving five properties, from pre-works planning and excavation to installation and reinstatement.
Read articleSMP Septic Tank Upgrade Grant: Frequently Asked Questions
Ask our teamDo I need to involve my mortgage company?
Your mortgage lender may need to countersign the Unilateral Undertaking because the agreement remains attached to the property. The grant can cover countersigning costs where required, but it does not cover independent legal advice you choose to obtain.
How long does the whole thing take?
The process typically takes around six months from application to installation. Timescales depend on eligibility checks, the site assessment, grant approval, legal documents and scheduling the work. You must not allow installation work to begin until the SMP has confirmed approval.
What if my septic tank is in an awkward spot?
Restricted access, slopes and difficult ground conditions do not automatically prevent an upgrade. During the site assessment, we examine access for machinery, the existing drainage arrangement and the proposed plant location. We will explain any constraints or additional work before submitting the quotation.
Can I do landscaping or other work at the same time?
Yes, subject to the site and agreed schedule. Tell us about any landscaping, drainage or plumbing work before the project is approved so it can be planned correctly. Optional and ancillary work falls outside the grant and must be agreed and paid for separately.
What happens at the annual service?
A trained engineer checks that the treatment plant is operating as intended, deals with applicable consumables and produces a service record. Servicing during the first year is included within the approved grant. You are responsible for arranging and paying for annual servicing after that.
Who do I call if something goes wrong after installation?
Contact UKDP first, on 0800 028 9903. Your installation contract is directly with us, and our workmanship is covered by the applicable guarantee. We will establish what has happened and explain the next step. You can contact the SMP if you need further support relating to the grant scheme.
What if I am not in Bishop’s Sutton, can I still apply?
Not under the current phase, which is limited to designated parts of Bishop’s Sutton within the relevant River Itchen catchment. The SMP lists planned schemes separately and accepts expressions of interest from people outside existing areas, but this does not guarantee that funding will become available. Register your interest with us on 0800 028 9903 and we will let you know when your area becomes eligible.
Can a shared septic tank qualify for the grant?
Yes, a septic tank serving multiple homes may still qualify. UKDP will assess the shared system and determine what replacement is technically suitable. Where households jointly own the tank, the application must come from the property where the tank is physically located because that property will be bound by the Unilateral Undertaking.
Take the Next Step With Your SMP Grant Application
Think your property may qualify? Speak to our SMP team. We’ll explain the eligibility criteria, help you understand what information is required and show you how to select UKDP as your preferred installer. Call 0800 028 9903 or email smp@ukdpsolutions.co.uk.