BRON-water: Determining and Reporting the Environmental Impact of the Dutch Water Sector

Background, significance and urgency for the sector

Background and significance for drinking water utilities
The EU announced the Corporate Sustainability Reporting Directive (CSRD) in 2022. Although most drinking water utilities are no longer subject to CSRD requirements, their own sustainability ambitions mean that they want to continue to quantify and report their environmental impact in line with the CSRD themes. In addition, clients who are subject to CSRD requirements sometimes ask about the environmental impact of drinking water utilities, as a result of which this information is required indirectly after all.

The ambitions of the drinking water utilities and the CSRD requirements provide an opportunity to develop a collective methodology for the quantification of environmental impact and to anchor its application in the sector. In the short term, we are therefore avoiding a situation in which each drinking water utility has to reinvent the wheel. In the longer term – once the collective approach has been developed and integrated in the sector – this will provide a framework for:

• Jointly addressing changes in legislation and scientific understanding;
• Identifying knowledge questions and directing research;
• Understanding environmental performance at the sectoral level;
• Sectoral benchmarking analogous with greenhouse gas emissions in the three-yearly Vewin performance comparison.

Background and significance for water authorities
The developments at water authorities and drinking water utilities are currently separate from each other, with distinct substantive emphases, different working methods and different speeds. Some degree of harmonisation between the drinking water utilities on one hand and the water authorities on the other with respect to sustainability reporting is desirable. This would open up opportunities for knowledge sharing and perhaps for the mutual use or harmonisation of each other’s approaches. With a mature method, this would even make it possible to map the environmental impact of the water sector as a whole ‘from source to source’.

In BRON-water, a project in the WiCE programme, we aim to work together with the water authorities on the first step towards complementary methodologies for environmental impact analyses and sustainability reporting in the water sector. To this end, the water authorities have stated their wish to initially develop the method further with a view to analysing the environmental impact of water treatment effluent. Effluent quality is not routinely included in the environmental impact analyses currently used in the sector. KWR has worked with the water authorities previously on this topic and has therefore already built up some knowledge (Van den Brand et al., 2025).

Intended result, deliverables and impact

The drinking water utilities (and the industry) will acquire:

• A scientifically-based method and calculation tool to determine their individual environmental impact in line with the current working method and management structure of PCD 11 and the CSRD themes. During the project, work will take place on anchoring the method in the sector.
• An understanding of the environmental impact of the sector, and the key factors that determine its environmental impact. If, during the course of the project, the drinking water utilities apply the method and calculation tool in a uniform way and share the results with KWR, we can present the insight of the sector as a whole.
• Opportunities for benchmarking (if desired) covering more than just carbon emissions as is currently the case.

The water authorities will acquire:

• A further elaboration of the recently developed method for determining the environmental impact of water treatment effluent.

The water sector will have:

• A joint knowledge base about the quantification of environmental impact, an understanding of opportunities, and possibilities to work towards a method for impact analysis ‘from source to source’.
• On that basis, it will be possible in the future to draw an integrated picture of the environmental impact of water in the various stages of its cycle.

The impact of the BRON-water project will be found in the application of the method and the calculation tool. This will provide utilities with concrete information that can help to reduce their environmental impact in a targeted way. For example, a baseline measurement of total environmental impact, which material streams in an organisation cause most environmental impact, and what the effects of intended sustainability measures may be on total environmental impact.