Future-proof wastewater treatment: scenario study of wastewater treatment plants

Drents Overijsselse Delta (WDODelta - regional water board) is focusing on the future. One important question for them is what measures are needed to make wastewater treatment plants future-proof and remain in line with the most important administrative policy objectives?

To answer this question we conducted a scenario study together with a project team from the water board. The study offers input for the WDODelta asset management plan, which will later be translated into a tactical asset management plan. The assets’ current status and performance formed the starting points for the study. We then compared these with current and future performance requirements, policy and other developments and innovations. Demographic, statutory and technological developments up to reference year 2030 were also taken into account. Guiding policy developments included the European Water Framework Directive (WFD) and concrete policy objectives with a focus on climate, energy and circularity.

This study explored measures that could meet the various policy objectives. We used a longlist and shortlist of measures focusing on the treatment plants’ water and sludge lines to compile sets of solutions that fulfil the WFD objectives and climate and circularity policy. As measures that can help fulfil one policy objective can have a conflicting effect on another policy objective, we measured the impact of these measures repeatedly.

The integral costs (total cost of ownership, TCO) and the emission of greenhouse gases (in terms of CO₂ equivalents) were used as the primary basis to compare the impact of the measures. CO₂ equivalents were also expressed in monetary terms and included in the TCO.

The end result of the study is a clear overview of the water board’s assets, the measures that can be taken to achieve policy objectives and their target range and costs. The study also clarifies measures that are mutually exclusive or sequential, providing input for further decision-making and for the WDODelta strategic asset management plan.