Individual Wastewater Treatment (IBA) 

In most places in the Netherlands, wastewater is transported through sewers to a central location where it is treated. In some places, installing sewers is difficult or very expensive. In those places, small wastewater-treatment plants (IBA's) are installed. These treat water and discharge it into surface water or into the soil. An IBA is an Individual Wastewater Treatment Plant, also known as a mini-treatment plant. Do you use an IBA? You can find more information here.

A healthy living environment

Clean water is important to a healthy living environment. As water authority, we work hard to provide cleaner and healthier water, but we cannot do it alone. We need your help! When you use an IBA on a daily basis, you have a significant impact on the operation of the mini-treatment system without even realising it. Therefore, it is important to know how to use the installation, who is responsible for what, what to do in the event of an incident, and how maintenance is organised.

What does a mini-treatment system do?

An IBA purifies your wastewater and discharges it into surface water. The installation is tailored to your volume and type of wastewater. 

Who maintains my IBA?

You are responsible for maintenance. To ensure the system works properly, the mini-purification system should have a service at least once a year. 

Why do I need to maintain my IBA?

Proper use of your IBA reduces the risk of blockages and malfunctions. It prevents unpleasant odours in your garden and diseases caused by coliform bacteria. It also helps to keep our water clean. This is important for nature and the quality of surface water. 

What should I do about odour nuisance from the mini-treatment system?

During the first 3 to 4 weeks, some odour may be released through the vent. This is normal and indicates that the system is functioning properly. If you still smell an odour after 4 weeks, please contact the service department.

What should I do about unpleasant odours coming from the sewer system in and around my home?

Odours can arise due to a failure to make adjustments to the house connection. Check that all drainage points are equipped with an odour trap, such as a siphon or water seal. Make sure the house connection is properly vented and aerated.

What is my own responsibility?

Blockages between your property and the mini-treatment plant are your responsibility. During unblocking, solid waste particles can enter the mini-treatment plant and cause blockages. Prevent this by collecting the waste and disposing of it in the household waste container. 

When should I call the repair service?

Malfunctions can have various causes. Click on the button below to see what you can possibly fix yourself and when you should call the repair service. 

Malfunction individual wastewater treatment (IBA)

Tips for maintaining your individual wastewater treatment (IBA)

If you have a mini-treatment system and want to maintain it better,  these six steps will help you do so. Download the flyer and hang it in a convenient place in your home. 

Tips IBA: Contribute to cleaner wastewater.pdf (Dutch only)

Division of responsibilities for sewage and wastewater

The water authority determines how domestic wastewater should be processed. We supervise the discharge of water into surface water. The local council deals with constructing and managing the sewer system. As a resident (household), you make sure you are connected to the sewer system or a septic tank or that you have another facility for the individual treatment of your wastewater.

Decision on discharge of household wastewater

The decision on the discharge of household wastewater contains regulations for discharging domestic wastewater into surface water. For example, toilet water or dishwater. Specific regulations apply depending on the situation (planned sewers or not, new or existing home). The regulations for the discharge of domestic wastewater from private individuals can be found in our Water-Authority Regulation, under Appendix 5.

More information