Working with the Solent Mitigation Partnership to upgrade your septic tank. Receive up to £30,000 to replace your existing septic tank with a modern treatment plant — fully managed by UKDP from survey through to sign-off.
Is the SMP grant for you?
The scheme is currently open to homeowners in specific parts of Bishop Sutton along the River Itchen. To qualify, you will need to meet all of the following:
- Your property is in the eligible area of Bishop Sutton
- You own the property and live in it
- Your septic tank is over 10 years old
- Your property falls within the correct water catchment
Priority is given to properties in Council Tax bands A to D. Not sure if you qualify? Call us on 0800 028 9903 and we will check for you in five minutes. No obligation, no pressure.
What the grant covers
The SMP grant covers the full cost of replacing your existing septic tank with a modern Package Treatment Plant. That includes:
- The feasibility survey
- The new treatment system
- Installation and commissioning
- First year servicing
- Building Regulations approval
- Environmental Permit approval, if required
- Planning application fees, if required
- Title searches and legal costs
- Countersigning costs, if required
The only costs you may need to cover yourself are electricity to run the system, any optional extras such as landscaping or internal plumbing upgrades, servicing after the first year, and eventual replacement when the system reaches the end of its lifespan.
Why choose UKDP for your install
UKDP is a specialist off-mains drainage company with over 15 years’ experience, and we have helped thousands of homeowners across the UK with septic tanks, sewage treatment plants and related drainage systems. Choosing us as your installer means:
15–20 year warranty
A 15 to 20 year manufacturer warranty on the tank structure. We install modern package treatment plants from all leading UK manufacturers including Klargester, Marsh, Tricel and WTE, with particular focus on systems suited to nutrient-sensitive catchments like the Solent.
10-year guarantee
A 10-year Insurance Backed Guarantee on our workmanship, at no additional cost to you. Together with the manufacturer warranty, that covers both the product and the install for the long term.
Full lifecycle service
We handle everything from the initial survey through to Building Control sign-off, Environment Agency permits, commissioning and ongoing maintenance. You deal with one company throughout.
Insured & accredited
£15 million in Public Liability, Employer’s Liability and Professional Indemnity insurance. CHAS accredited. Appointed drainage specialist for the UK’s largest home warranty provider, and trusted by national loss adjusting firms and insurers.
Invested in the Solent
UKDP pledges a contribution from every SMP installation to the Hampshire & Isle of Wight Wildlife Trust, supporting its work to protect the rivers, wetlands and marine habitats that this grant scheme is designed to safeguard. An installer working to protect the Solent should be invested in the Solent.
How the process works, step by step
The full process typically takes around six months from application to completed install. Here is how UKDP fits in.
1
You apply to the SMP
You fill out the SMP’s online application form and receive a reference number. If you need help gathering the information you need, such as your tank’s age or last service date, give us a call and we will talk you through it.
2
The SMP confirms your eligibility
The SMP checks your property type, location, tank age, ownership status and Council Tax band.
3
UKDP visits your property
We come out, assess your current system, design a suitable replacement, and produce the technical report and quote the SMP needs to make a decision. This is where most of the technical work happens, and we handle all of it.
4
The SMP makes its decision
Quotes and technical reports are assessed on the first Wednesday of each month. You will hear back by the second Wednesday with the decision and your grant amount.
5
You sign the Grant Finance Agreement
You sign the Finance Agreement and the Unilateral Undertaking. If you have a mortgage, your lender will need to countersign, and we can help guide you through that step.
6
We install
We agree dates with you, carry out the install, commission the new system, and hand over your completion pack.
7
Year one servicing, included
We carry out your six month and twelve month services as part of the grant. After that, we can stay on as your ongoing service provider, or you are free to choose someone else.
What you receive when the job is done
On completion, UKDP provides a full handover pack including:
- Manufacturer warranties (15 to 20 years on the tank structure, depending on the system installed)
- 10-year Insurance Backed Guarantee on UKDP’s workmanship
- Groundworks guarantee
- Electrical certification
- Building Regulations certificate
- Service schedule and maintenance guidance
Everything you need for your records, your mortgage company, and any future sale of the property.
What the Unilateral Undertaking means for you
In exchange for the grant, the SMP asks you to sign a Unilateral Undertaking. This is the legal mechanism that makes the environmental benefit permanent, and it is worth understanding clearly before you apply. The Undertaking commits you, and any future owner of the property, to three things:
- Maintaining the new treatment system properly
- Keeping the agreement in place for 100 years, regardless of who owns the property
- Ensuring that any future replacement is of equal or better environmental quality
In return, the nutrient credits created by your upgrade are transferred to the SMP, where they support environmentally responsible housing delivery across Hampshire. In practical terms, this means servicing your system as recommended, keeping the paperwork, and disclosing the agreement to any buyer if you sell. None of this is unusual for a treatment plant, and UKDP handles the documentation side of it as part of the install.
Frequently asked questions
Do I need to involve my mortgage company?
Yes. The Unilateral Undertaking is a legal agreement attached to the property, so your mortgage lender will need to countersign it. The SMP covers the countersigning cost, and we can help guide you through the process.
How long does the whole thing take?
Around six months from application to completed install, in most cases. The grant decision itself happens monthly, on the second Wednesday of each month.
What if my septic tank is in an awkward spot?
We specialise in rural and access-constrained sites. Tight access, sloped gardens, and difficult ground conditions are normal for us, and we will tell you honestly at the survey stage if there is anything unusual to plan for.
Can I do landscaping or other work at the same time?
Yes, although the cost of optional extra works is not covered by the grant. If you are thinking about combining the install with other garden or drainage work, mention it at the survey and we can co-ordinate.
What happens at the annual service?
A trained engineer checks the system is running correctly, replaces any consumables, and produces a service record. Your first two services, at six months and twelve months, are included in the grant.
Who do I call if something goes wrong after install?
Call us first, on 0800 028 9903. We carry the workmanship guarantee and can resolve most issues directly. If you ever need to escalate, the SMP team is there as a second point of contact.
What if I am not in Bishop Sutton, can I still apply?
Not at present. The scheme is currently limited to parts of Bishop Sutton along the Itchen, but it is expected to expand. Register your interest with us on 0800 028 9903 and we will let you know when your area becomes eligible.
