If your property is not connected to the public sewer, you have an off-mains drainage system. Across rural Kent, Surrey and Sussex, that almost always means one of two things: a septic tank or a cesspit.

How A Septic Tank Works

A septic tank is a treatment system. Solids settle to the bottom as sludge. Fats float to the top as scum. The clarified liquid flows out into a soakaway or drainage field. The tank only fills with sludge and scum – typically only needing emptying once a year.

How A Cesspit Works

A cesspit is a sealed holding tank. It does not treat anything and it does not discharge anywhere. Every drop of wastewater stays there until a tanker pumps it out. Much more expensive to run over time.

How To Tell Which One You Have

  • Check the documentation.
  • Look at the chamber. A septic tank has two chambers with an inlet and outlet. A cesspit has one chamber and inlet only.
  • Track the emptying frequency. Every couple of months = cesspit. Once a year = septic tank.
  • Ask the tanker company.

Legal Compliance: The General Binding Rules

In England, septic tanks must discharge to a properly functioning drainage field, not directly to a watercourse. If your septic tank discharges to a stream or ditch, it must be upgraded.

Running Costs Compared

  • Septic tank empty frequency: typically once a year.
  • Cesspit empty frequency: every few weeks to months.
  • Annual septic tank running cost: £200-£350.
  • Annual cesspit running cost: often £1,000+.

Essential Maintenance For Both

  • Avoid harsh chemicals.
  • Stick to the Three Ps.
  • Keep surface water out.
  • Do not park or drive over the tank or drainage field.
  • Empty on a schedule.

Call Call2Drain

Call 01892 571 555 for off-mains advice.