WOULD YOU LIKE TO STAY INFORMED ABOUT SUSTAINABILITY AT THE UT?

Water is important: it’s important for you as a person, for nature and for the university, too. We believe it is important to treat water well in order to preserve the equilibrium of the ecosystem. In this section, we will discuss the consumption of drinking water, rainwater and wastewater at the University of Twente.

Drinking water

This graph shows drinking water consumption over the past five years. The increase in water consumption can mainly be explained by the fact that drinking water is used to cool research equipment.

 


This graph shows water consumption throughout the year between January 2017 and June 2018.



This graph shows water consumption throughout the year between January 2017 and June 2018.

Encouraging the use of tap water

The UT encourages the use of tap water, as this prevents unnecessary plastic use. Several outdoor Join the Pipe water points can be found on campus: on the O&O square, at the athletics track and at the multi-field. Inside, you can refill a bottle in the toilets or at one of the coffee machines. Join The Pipe uses the income generated by these points to fund clean drinking water projects in developing countries. For more info, visit https://join-the-pipe.org

Rainwater

Precipitation intensity is increasing, and the current sewage system may not always be able to cope. The UT focuses on collecting rainwater and facilitating infiltration into the soil. All rainwater-related measures taken at the UT are listed below.

Water storage under the faculty club car park

We have installed a water buffer and infiltration system with a hollow space under the car park of the Faculty Club: AquaBASE. UT’s water storage system was one of the first in the Netherlands, and our campus was the test location. In the first year, results were monitored and the test was shown to be successful. The system consists of permeable stones interspaced with small joints to guarantee a good flow rate and infiltration capacity. The substrates feature hollow spaces, in which water is stored and have sufficient load-bearing capacity and stability to be used in car parks. This system retains water for longer, so that it infiltrates into the soil more slowly. For more technical information about these substrates, visit this page on AquaBASE (Dutch only). 

Gravel layer under car park 2

Underneath P2 is a thick layer of gravel which lets the soil retain more water, so that it can infiltrate deeper into the soil at a lower pace.

Ponds

Most rainwater that falls onto UT buildings ends up in the various ponds on campus via drainpipes.

Spraying lawns with collected rainwater

If necessary, the event grounds are sprayed with rainwater collected from the ponds.

Plan: new treatment filter for clean water basin

All rainwater that falls on Hogenkamp will be filtered, probably with membrane technology, and stored in the clean water basin under the high part of the athletics track. This water can then be used to water all sports fields.

Technohal – rainwater used to flush toilets

Rainwater is stored in a 20m3 tank adjacent to the Technohal and used to flush toilets.

Water collection in brooks on campus

The Roombeek, Bolhaarsbeek and Drienerbeek can all be found on campus and flow through several ponds. These ponds have an important function in the collection of rainwater, both for the UT and for the surrounding area.

Helophyte filter for the cold circulation system

The cold circulation system (the basin in front of the Horst building) contains more than 10 million litres of water which has to be treated in order to prevent corrosion and deposits on the cooling system, which we do by means of a helophyte filter. A helophyte filter uses helophytes to treat wastewater up to a point at which it is no longer harmful to the environment. Helophytes are plants that grow above water but take root in very wet soil, and they are capable of transporting oxygen to their roots themselves. 

Behind the Horst, there are two fields that have been covered in gravel, sand and anti-root foil, on which we have planted reed plants. The dirty water flows onto the field on one side, before sinking through the gravel. In the soil, the waste materials are converted into nutrients for the plants in the filter. When it leaves the filter, the water is clean enough to return to the cold circulation system.

Surface water used for cooling system

The cold circulation system is a large basin measuring 10 metres deep and 36 metres wide that holds 10 million litres of cold water, which is used during the day to cool the connected buildings and research equipment. The chillers mainly cool the water at night, because the water temperature is naturally colder then, which saves a lot of energy. On top of that, it also saves costs, because the night rate for energy is lower than the day rate. The cool nighttime climate and air-cooled chillers join forces to cool the water down to approximately 8 to 10 degrees Celsius. For more information, visit the page on ‘Energy’.

Wastewater

The wastewater passes through the pumping station on the UT campus to the Water Board’s water treatment plant in Enschede. The Vechtstromen Water Board (Dutch only) is responsible for treating the wastewater, after which it flows to Kristalbad (Dutch only). The Vechtstromen Water Board also monitors the wastewater at the UT, taking quarterly samples from the UT’s pumping station, which are then tested at a laboratory. On top of that, the amount of wastewater, the flow rate, is recorded and the concentration levels of heavy metals and oxygen-binding susbtances in the wastewater are measured. These parameters are used to determine the number of pollution units on which the levy charged to the UT is based (Water Boards Act (Dutch only)).

There are strict procedures in place in laboratories to limit the concentration levels of chemicals in wastewater. Used glassware is rinsed 3 times with a small amount of water, as 3 rinses with a small amount are considerably more effective and environmentally friendly than a single rinse with more water. Chemical concentration levels will still be too high in the water used for the first 2 rinses, and this water must be collected and disposed of as hazardous waste. When cleaning chemically contaminated glassware, only the water used for the 3rd rinse can be flushed down the sewer.

Which cuts have we made?

Rainwater used to flush toilets

In the Technohal, collected rainwater is used to flush toilets. The softened water that is used to mist condensers 1000h per year is also reused for flushing toilets.

Waterless urinals

In the Sports centre, Paviljoen and the ground floor of Zilverling, all urinals are waterless.

Sensor tap runs shorter

Many sinks are equipped with a sensor tap, which runs for 6 seconds. This is shorter than the average user would leave the tap on, resulting in savings of 3,000l/day.

Join the pipe water points

The UT encourages the use of tap water, as this prevents unnecessary plastic use. Several outdoor Join the Pipe water points can be found on campus: on the O&O square, at the athletics track and at the multi-field. Inside, you can refill a bottle in the toilets or at one of the coffee machines. Join The Pipe uses the income generated by these points to fund clean drinking water projects in developing countries. The less plastic bottles we use, the less plastic bottles will have to be transported. For more information, visit Join the Pipe’s website.

What can you do?

  • Cut a minute off your showers.
  • Use a water-saving tap and shower head.
  • Close the tap as quickly as possible.
  • Do not use the toilet as a bin: contact lenses, tampons and deep-frying fat don't belong there.
  • Drink tap water instead of bottled water
  • Use rainwater, connect a rain barrel. Lime-free water is also better for your plants.