Sustainable working methods

Lower greenhouse gas emissions

The increase in greenhouse gases in the atmosphere causes global warming. We ensure that we emit less and less of these gases by:

• Limiting energy demand.
• Generating our own energy.
• Purchasing green energy that we cannot generate ourselves.
• Innovating in our wastewater treatment plants (WWTPs)
• Selecting materials, additives, and raw materials that contribute to the lowest possible emissions.

This means that we:

• Work with other water authorities to find ways to reduce nitrous oxide and methane emissions from wastewater treatment plants.
• Generate sustainable energy with solar panels and biogas production.
• Investigate how we can reduce our energy consumption.
• Work to preventing peat oxidation. This is a natural process in which peat soil decomposes and CO2 is released.
• Electrify our vehicle fleet and focusing on the use of public transport and bicycles.
• Replace our diesel pumping stations with electric pumping stations, or running them on HVO diesel.

We are working in a more circular manner

If we do not use raw materials in a circular manner, natural resources will become depleted. We are increasingly working in a circular manner by:

• Opting for reusing materials and raw materials in our projects, where possible.
• Working with biobased and renewable materials, where possible.
• Seeing which raw materials we can recover in our treatment process.
• Offering materials that we no longer use to third parties.

This means that we:

• Provide buildings with a 'materials passport'. This will make it easier to reuse materials in the future.
• Use FSC-certified wood instead of steel and plastic, where possible.
• Investigate whether we can recover substances such as cellulose, phosphate, and Kaumera at our treatment plants.
• Make more frequent use of circular marketplaces where second-hand construction a nd other materials change hands.

We use four key priorities in our daily work to bring our sustainability ambitions closer:

Sustainable Soil, Road Construction, and Hydraulic Engineering

We apply the environmental indicator, the ambition web, the CO₂ performance ladder, and/or DuboCalc to achieve more sustainable projects. We include the estimated greenhouse gas emissions in all our proposals. We do this for the entire lifespan, not just for the construction phase. 

Circular design principles for new construction, replacement, and maintenance projects

We reuse released materials and raw materials instead of purchasing new materials/raw materials. We start by looking at our own possibilities and then at the possibilities offered by the market.
We aim to repair if the costs are no more than 2/3 of the replacement costs.
If we have to replace something, we also look at used alternatives first before opting for 'new'.
We are alert to recycling plastics and other environmentally harmful substances. We want to contribute as little as possible to spreading problematic substances.

Less rainwater at treatment plants

We treat up to five times more water than the water used by households and businesses at our treatment plants. We  strive for a ratio of 1:1. Disconnection is necessary to reduce the amount of rainwater entering our treatment plants via the sewer system. This requires major investments from our partners in the water chain. In the long term, we will save on new construction and operation of the treatment plants. Costs and revenues are shared between different parties. This requires agreements in view of the ultimate aim of lower social costs.

Awareness and knowledge

We inform our employees and partners of what we do and how it contributes to our sustainability ambitions. Annual updates and figures on progress in key areas raise awareness.

Not everything can be done at once. We have to use our time, capacity, and money wisely. Therefore, we use an assessment framework to give opportunities for and developments in more sustainable working methods the right place in our daily work:

1. We make our operations more sustainable at logical moments: when we invest in replacements or new construction, or during tenders for goods and services.
2. If we do not capitalise on opportunities for sustainability ourselves, we do so together with others or leave it to public or private partners. The choice of what we do ourselves, together, or leave to others depends on the contribution to our goals in relation to costs, returns, and risks.
3. The order of the "trias energetica" (1. use less, 2. use sustainable energy, 3. be as economical as possible with the fossil fuels we still need) is key to reducing greenhouse gas emissions. 
4. The cost may come before the benefit: limited additional investments or any additional costs are possible if significant gains in sustainability can be achieved. 
5. For our energy generation, we consciously choose a mix of biogas, solar, and wind. This increases the likelihood of being able to use our own energy sources throughout the year.
6. We invest in projects for generating and/or storing renewable energy and/or projects for recovering and/or recycling raw materials if they can be recouped within their technical lifespan. 
7. We want to learn from our experiences with sustainability in practice. If we still see major risks, we will start with pilot projects. We share our knowledge with other government bodies and the market.