The concept of wastewater treatment has undergone drastic changes in recent years, not so much yet in its engineering practice, but more in its approach. The major focus on wastewater treatment has been for a century the treatment of contaminated water to environmentally and sanitarily acceptable levels. Today, while obviously maintaining satisfactory treatment results with contained operational costs, the immediate reuse of treated water for irrigation or as precursor for drinking water production, as well as the use of wastewater constituents in the bioeconomy have started becoming objectives when designing a treatment facility. This dogma shift is driven by increasing fresh-water scarcity and the need to decrease the environmental impact of wastewater treatment. A reduced impact of wastewater treatment can be obtained by minimizing direct and indirect greenhouse gas emissions and by recovering bio-based products that replace fossil-based products in the bioeconomy. The challenge for today’s environmental engineers working in wastewater treatment is immense as the entry into the bioeconomy of bio-based products derived from wastewater requires cross-sectorial competencies, i.e., knowledge of the application of bio-based products, product requirements, and how the treatment process influences product properties. Modern engineering of a wastewater treatment plant therefore does not stop anymore at the influent to the receiving water but extends into various branches of industry that may benefit from wastewater derived bio-based products, as for example agriculture, chemistry or animal breeding/husbandry. In our presentation, we will illustrate the importance of considering a wider system boundary when attempting a decreased environmental impact. In our example, we show how land-application of sewage sludge and the down-stream management of bio-based products may impact the environmental impact of the overall wastewater treatment process. This will be done using life cycle assessment as tool for the eco-design of a novel, putative bioprocess for wastewater treatment using oxygenic photogranules. Biomass reuse and valorization typically requires a dewatering step generating a liquid flux of water enriched in micro- and macronutrients. This flux is often overlooked in modeling (biokinetic or life cycle) but may deserve attention as suitable point of attack for the recovery of nutrients as will be shown.