Septic tank, treatment plant or cesspit: which could suit your site?

How the chooser works

Choose your nation, then tell us where treated water could go at your property, whether there's mains electricity near where the system would sit, and what matters most to you. The chooser compares your answers with the official rules for your nation and with what each kind of system needs, and shows which could suit, each with the official page it comes from and the date we checked it.

If we haven't checked a rule for your nation yet, the chooser says so instead of guessing, repeats your answers back and links to the regulator's own guidance.

What it can't tell you

Whether the ground can take a drainage field, and where an outlet could go, depends on your site. An installer will assess that, often with a percolation test. The chooser is a starting point for that conversation, not a design.

Next steps

Get written quotes for the systems that could suit, and line them up with the quote comparison to see what each one leaves out. For the differences in how each system works, see cesspit, septic tank and treatment plant: the difference.