12 point checklist for homes without mains drainage

29 September 2025 by CSG

Buying a home with a private drainage system can feel a little daunting if you’ve never dealt with one before. Unlike properties connected to the mains sewer, homes with a septic tank, cesspit or treatment plant require regular care and ongoing maintenance. Failure to understand the system you’re inheriting can lead to unexpected costs, compliance issues, or even difficulties when it comes to selling your property in the future.

That’s why it’s so important to ask the right questions before you purchase your property. From the type of system that is in place to its compliance with environmental regulations, knowing what to look for can help you make an informed decision and avoid nasty surprises down the line.

In this guide, we’ll walk you through the key things to check when buying a property with a private drainage system and how CSG can help you manage it with ease once you’ve moved in.

Our checklist

1. Type of system – Identify whether the property has a septic tank, cesspit or treatment plant.

2. Location of the system – Check where the tank is situated. Is it entirely on your land or shared with neighbours?

3. Ownership and responsibility – Confirm whether you are solely responsible for the system or if it’s jointly used and maintained with neighbouring properties. What agreements are in place around emptying, maintenance and repair? What is the current owner’s relationship with the neighbouring property owners?

4. Compliance with regulations – Ensure the system meets the Environment Agency’s General Binding Rules. Most importantly, make sure a septic tank does not discharge into a watercourse.

5. Upgrade requirements – Ask whether the system has been updated since the 2020 regulations or if costly works might be needed.

6. Maintenance history – Request service records, emptying receipts and inspection reports. Lack of documentation may indicate poor upkeep.

7. Emptying frequency – Clarify how often the system needs to be emptied and the typical cost.

8. Access for tankers – Make sure there is vehicle access for emptying and maintenance. Limited access can make servicing more expensive or problematic.

9. Soakaway or drainage field condition – Ask about the state of the soakaway/drainage field. Is there enough space for a replacement drainage field if it fails?

10. Running costs – Factor in regular emptying, servicing and electricity use (for treatment plants).

11. Insurance cover – Check whether your home insurance includes private drainage system cover or if additional protection is needed.

12. Future saleability – Consider how the system may affect resale value, mortgage approval or buyer interest.

Owning a property with a septic tank, cesspit or sewage treatment plant doesn’t have to be complicated. By asking the right questions upfront and keeping on top of regular maintenance, you can protect both your home and the environment. Partnering with a trusted waste management company ensures your system runs smoothly, stays compliant, and doesn’t become a costly headache later down the line.

How CSG can help – regular servicing and collections

We deliver domestic waste services to householders every day, specialising in the collection and treatment of household sewage.

When your septic tank, cesspit or sewage treatment plant needs emptying, you can rely on our friendly team of drivers to complete the job quickly and carefully.

We also offer dependable, low-cost maintenance and repair services, including blockage removal, sewage system servicing or the reassurance of 24-hour emergency cover when things go wrong.

Want to know more? Contact us today by calling 0800 011 6600