Septic tanks and sewage treatment plants: what you need to do: Your property has a new discharge

There are things to do when your property has a “new discharge” where you discharge sewage into the ground or surface water.

You have a new discharge if one or more of the following conditions are true:

• it has not started yet (e.g. if you are still in the planning stages for building a house or business)
• it started on or after January 1, 2015
• the type changed on or after January 1, 2015 (from groundwater to surface water or vice versa).
• it shifted more than 10 meters on or after January 1, 2015
• Since January 1, 2015, the runoff has increased to more than 2 cubic meters (2,000 liters) per day if it ends up in the ground, or to more than 5 cubic meters (5,000 liters) per day if it ends up in surface water

If you’re buying a home that already has a septic tank or sewage treatment plant, check to see when it was installed to see if it is considered new or existing.

Connect to a public sewer

If you have a new drain, it must be connected to a main sewer system (also known as a “public dirt sewer”) if the environmental authority decides this to be “sensible”.

Read the guide to “Discharge in sewers” ​​to find out which criteria apply when connecting different types of property to a public sewer system.

The environmental agency decides what is appropriate based on:

• How close are you to a public sewer system?
• the cost of connecting to a public sewer system compared to the cost of installing a wastewater treatment plant
• whether there is something in the landscape that prevents the connection to the public sewer system – for example a large road
• whether your sewage treatment plant would have ecological advantages – for example if it reused treated wastewater

The Environment Agency will not give you a permit for a wastewater treatment plant if it is reasonable for you to connect to the public sewer system.

If connecting to a public sewer doesn’t make sense, you’ll need to install a sewage treatment system to treat your sewage.

Installation of a new wastewater treatment plant

You should only install a sewage treatment system if a connection to a public sewage system does not make sense.

To install a new sewage treatment plant, you need a building authority approval.

You may also need a building permit. Check with your local council.

Check that you comply with the general binding rules

If you already have or are installing a septic tank or sewage treatment plant and the connection to a public sewage system is unreasonable, check whether this corresponds to the “generally binding rules”.

If you do not comply with the general binding rules

You have to try to adhere to the generally binding rules, for example by changing your wastewater treatment plant.

If you cannot comply with the generally binding rules, you must apply for a permit.