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Water treatment and reuse

The treatment and reuse of water has now become a top priority worldwide. In many countries, water scarcity is so great and natural sources so depleted or polluted that it is no longer possible to do it without water treatment systems. For environmental reasons alone, water recycling is now absolutely essential for new construction as well as retrofit and even municipal projects worldwide.

Our water sources include rainwater or surface water, well water, effluent water from small wastewater treatment plants or greywater. Depending on the degree of contamination and treatment technology, different water qualities can be achieved. It can be used to irrigate plants and be fed into the household as process or drinking water. We specialize in decentralized and semi-decentralized systems for all climatic conditions. For over 25 years and in well over 30,000 systems, our customers are now recycling water worldwide, saving several million m³ of water annually. We develop, produce and supply a huge range of products from simple rainwater harvesting for the garden to complex treatment systems for greywater or potable water supply. The systems are used at:

  • Domestic houses
  • Apartment houses
  • Hotels
  • Office buildings
  • Production plants
  • Public buildings
  • Schools
  • Quarters

With our systems, it is usually possible to save over 50%, and in some cases even up to 100%, of the original water consumption and thus the water costs. Due to the strongly rising prices and low interest rates, many systems are now even so profitable that an investment pays for itself within a few years. Operator models are possible for larger systems.

Fields of application


Rainwater harvesting

With rainwater, a productive source is available in many areas of the world, providing you with free water of excellent quality.

Learn more about rainwater harvesting for commerce

Learn more about rainwater harvesting for single-family homes


Greywater recycling

In greywater recycling, daily, low-polluted water from showers, hand-washing sinks and the washing machine is treated and reused.

Learn more about greywater recycling for commerce

Learn more about greywater recycling for single-family homes


Potable water production

The quality of rainwater is often so good that it can be made drinkable with just a few treatment steps.

Read more about potable water production and greywater harvesting for commerce

Read more about potable water production and greywater harvesting for single-family homes


Process water from small sewage treatment plants

The discharge water from a small sewage treatment plant can be treated into process water and used for toilet flushing or garden irrigation.

Read more about process water from small sewage treatment plants


Adiabatic building cooling

Use rainwater to save 80% energy for building cooling and costs for water softeners.

Read more about adiabatic building cooling

Purification stages in water treatment

In the field of water treatment, different filters and filter stages can be used to create different quality levels in the water. These range from process water to potable water.


Filter method


AQUALOOP membrane

UV filtration

Activated carbon

RainwaterPotable water





 Adiabatic cooling



GreywaterProcess water


Effluent water of a small

sewage treatment plant


 Process water


Pre-assembled complete systems

Our complete systems with AQUALOOP ultrafiltration membranes as well as biological and chemical purification offer the best technologies for producing reusable process water in the smallest of spaces. We offer our systems in nine different sizes in order to be able to present a suitable solution for every commonly required treatment volume. Find out more about the technology and design of our complete systems, which are suitable for recycling grey water and wastewater from small wastewater treatment plants.

More on complete recycling systems


I-CONNECT Monitoring

With I-CONNECT, consisting of a control unit and a web application, you can easily monitor, control and configure your water treatment systems yourself.

  • Secure plug & play internet access without router settings
  • Remote access to the systems via web portal or app
  • Transmission of fault and status messages via push and email
  • Clear system visualization
  • Automatic logging and storage of selected parameter data.
  • Optimization of system operation through data evaluation
  • Online update of the control unit software possible



AQUALOOP installation kit

The AQUALOOP installation kit comprises a package of components for biodegradation and ultrafiltration, which can be used to create various modular systems for water treatment and reuse.

  • Bioreactor technology for pre-treatment of organically contaminated water
  • sterilization and crystal-clear water with unique ultrafiltration with hollow fibre membrane technology
  • Modular design for any system size
  • minimal maintenance thanks to integrated backwash technology
  • Optimum price-performance ratio

More about the AQUALOOP installation kit

Project support from A to Z

There are many aspects to consider when planning and implementing a construction project. In a short time, you have to make many decisions that affect the entire construction phase. We accompany you through all phases, from planning to execution of your project.

  • Concept development and price calculation for the preliminary planning
  • Dimensioning with Rainplaner Software
  • Compilation of tender texts
  • Creation of CAD system drawings
  • Support of the executing companies
  • Commissioning Service
  • Monitoring of the systems

References with water treatment

In the field of water treatment and reuse, we have already been able to implement a number of small and large projects. On average, we have been able to save more than 50% of water consumption.

Do you have any questions or are you interested in a non-binding offer?
We are looking forward to your contact.

Here you will find brochures, instructions, technical drawings and much more.

With our knowledge portal, we offer you a wide range of information on the topics of rainwater management and water reuse.

Dimensioning of INTEWA products

Planning sheets for different applications

Rainplaner software