In the UK, it is estimated that around 5% of households are not connected to a mains drainage network. These therefore require an alternative system such as a septic tank, sewage treatment plant or cesspit. But who is responsible for a septic tank or other waste treatment system?


If you’re an owner-occupier and your property has a septic tank, it’s very straightforward: you are fully responsible for your septic tank. If there are any issues with it, it is up to you to fix them. You are also responsible for ensuring they comply with the rules and regulations governing off-mains drainage.

Adhering to the rules is legally-binding. You could end up with a pollution fine if you do not comply so make sure your system is compliant. Read more about septic tank regulations.

Landlords and Tenants

If you own a property which is tenanted, or you are a tenant yourself, it can become a little less clear who the responsibility lies with. Maintenance and responsibility can be written into the tenancy agreement. However, what happens if an issue started when the previous tenant lived there? Perhaps the issues span several lettings periods compounding the problem even further. In the worst-case scenario, who is liable to pay a pollution fine which may be accrued in the event of serious drainage issues?

If you are a landlord renting out a property with a septic tank you may need to put extra measures in place if you want the tenant to take responsibility for the septic tank. For example, you may need an inspection or service after the end of any tenancy period. You may want to expand the tenancy agreement to be very clear what is expected of the renters.

As a tenant, if it is written into the tenancy agreement that you have responsibility for the septic tank, you might also want to protect yourselves. Insisting upon an inspection to ensure you aren’t inheriting any legacy issues you would then be liable to pay for is one way to do this. Checking the schedule of maintenance and the obligations thereof is another before any serious issues can occur. Following the guidelines of the septic tank is important too. Flushing items down the toilet which will damage it for example will only create big and expensive problems for all involved.

Treat the off mains waste system at the property you live with respect and the right maintenance and it hopefully should not encounter any fundamental issues. However, if you do need any advice, speak to off mains drainage experts.

Alternatively, for more information on septic tank responsibility between tenants and landlords, read our blog.

Call Proseptic on: 01794 517 770 or book a visit.