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Preparing Denmark for climate changes

Jan Tøibner, Aarhus Water Ltd.

enmark is among the best in the world when it comes

to water supply and wastewater purification. Among

other things, this is due to a close and fruitful coopera-

tion between public water supply companies, forward-looking

municipalities, high-tech companies in the water industry and

innovative research and educational institutions. Danish water

solutions resonate internationally, and the country’s largest

suppliers of water and wastewater are ready to contribute

internationally with the most recent knowledge and solutions in

climate adaptation, energy optimization, green energy produc-

tion, reduction of water consumption and improvement of

drinking water quality.

One of the biggest issues facing the Danish water industry at present

is handling the global climate changes which affect the low-lying

parts of Denmark in the event of torrential rainstorms and rising

water levels. Even though the country benefits from large groundwa-

ter reservoirs, its water resources are constrained. These challenges

transgress municipal boundaries. Therefore, efforts now focus on

establishing greater units and new collaborations, so that water

supply companies will be better prepared to meet the challenges

of the future – both in terms of competence and technology – by

working together nationally. For example, the three largest water

supply companies in Denmark, Hofor, Vandcenter Syd and Aarhus

Vand, have started working together regionally, nationally and

internationally in the fields of security of supply, the environment,

energy and sustainability to name a few. One aim of this cooperation

is to contribute to the establishment of sustainable cities and smart

cities, for instance by exploiting rainwater.

Working with the entire water life cycle

Aarhus Vand A/S (Aarhus Water Ltd.) is one of the leading compa-

nies in the Danish water industry, and it works with the entire

life cycle of water – from consumers turning on the tap for a

drink of fresh water, to the return of purified wastewater from

households and industries to nature. The company operates in the

field of drinking water and wastewater treatment in the city and

its surrounding rural areas, working with the treatment, distribu-

tion and collection of wastewater. Cooperating closely with Aarhus

Kommune, Aarhus Vand is in charge of planning and executing

a wide variety of environmental and urban development projects

which take climate changes into consideration.

This requires Aarhus Vand to develop intelligent and future-proof

solutions. Therefore, the company has a long-standing tradition

of taking part in research and development projects at home and

abroad. It aims to be at the forefront of both knowledge and tech-

nology in the water and wastewater industry, and to ensure that

it continues to attract the foremost experts in the water sector.

These projects will support and improve Aarhus Vand’s

knowledge of the activities it wants to initiate to obtain

not only better and cheaper plants, products, services

and working processes, but also an environmental gain.

The purpose of taking part in research and develop-

ment projects is that they lead to the implementation

of new technology and methods. Many good and usable

results have been brought about by Aarhus Vand’s close

cooperation with researchers, advisers and internation-

ally-focused companies in the water industry. One

example is the testing of a new and efficient bottom

aeration system and the advanced online control of one

of the company’s water treatment plants, resulting in

a 45 per cent reduction in CO

emissions and power

consumption in wastewater treatment.

Another example is the full-scale system the company

has installed to remove phosphorus from wastewater

based on a pilot project. This system reduces the oper-

ating costs of the water treatment plant and produces

struvite, a clean and environmentally friendly fertilizer

containing high levels of phosphorus, which is a scarce

resource. The plant is a lighthouse project and the only

one of its kind in Denmark.

A third example is the Energy Smart Water Utilities

project, which includes an examination of the energy

potential of water by Aarhus Vand and several partners

across the water and energy sector. This is done by

using water pressure to produce power and by moving

power consumption in the water industry from day

to night, thereby exploiting renewable energy in the

water sector.

Another important topic for Aarhus Vand is to

make water visible in the town. The company benefits

from more than 10 years of experience in opening up

the city of Aarhus and making water visible, facilitat-

ing the use of water as a recreational element. At the

same time, this visibility also protects the city against

floods caused by torrential downpour. Examples

include the uncovering of the river that runs through

Aarhus city centre and the creation of the two lakes,

Aarslev Engsø and Egå Engsø, which purify water

from fields while also serving as large reservoirs. At

a national level, Aarhus Vand takes part in the ‘Vand

i byer’ (Water in cities) project along with Aarhus

Kommune among others. This is the biggest Danish

research project with an overall focus on the climate

adaptation of Danish cities, their infrastructure and

their water supply structure.

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