In Germany, the current sectoral urban planning often leads to inefficient use of resources, partly because municipalities lack integrated planning instruments and argumentation strength toward politics, investors, or citizens. The paper develops the ResourcePlan as (i) legal and (ii) a planning instrument to support the efficient use of resources in urban neighborhoods. The integrative, multi-methodological approach addresses the use of natural resources in the building and infrastructural sectors of (i) water (storm- and wastewater) management, (ii) construction and maintenance of buildings and infrastructure, (iii) urban energy system planning, and (iv) land-use planning. First, the development as legal instrument is carried out, providing (i) premises for integrating resource protection at all legal levels and (ii) options for implementing the ResourcePlan within German municipal structures. Second, the evaluation framework for resource efficiency of the urban neighborhoods is set up for usage as a planning instrument. The framework provides a two-stage process that runs through the phases of setting up and implementing the ResourcePlan. (Eco)system services are evaluated as well as life cycle assessment and economic aspects. As a legal instrument, the ResourcePlan integrates resource protection into municipal planning and decision-making processes. The multi-methodological evaluation framework helps to assess inter-disciplinary resource efficiency, supports the spatial identification of synergies and conflicting goals, and contributes to transparent, resource-optimized planning decisions.

Wastewater treatment plants (WWTPs) are under increasing pressure to enhance resource efficiency and reduce emissions into water bodies. The separation of urine within the catchment area may be an alternative to mitigate the need for costly expansions of central WWTPs. While previous investigations assumed a spatially uniform implementation of urine separation across the catchment area, the present study focuses on an adapted stochastic wastewater generation model, which allows the simulation of various wastewater streams (e.g., urine) on a household level. This enables the non-uniform separation of urine across a catchment area. The model is part of a holistic modelling framework to determine the influence of targeted urine separation in catchments on the operation and emissions of central WWTPs, which will be briefly introduced. The wastewater generation model is validated through an extensive sampling and measurement series. Results based on observed and simulated wastewater quantity and quality for a catchment area of 366 residents for two dry weather days indicate the suitability of the model for wastewater generation and transport modelling. Based on this, four scenarios for urine separation were defined. The results indicate a potential influence of spatial distribution on the peaks of total nitrogen and total phosphorus.

Wastewater management challenges can be addressed through source separation strategies, such as urine or grey water separation. To quantify advantages and avoid operational issues, an understanding of the impact of source separation on municipal wastewater treatment plant (WWTP) operation and effluent discharge is necessary. This can be achieved using activated sludge models. A key question is whether detailed chemical oxygen demand (COD) fractionation of domestic wastewater sub-streams is needed or if a load-based approach suffices for simulations. Determining COD fractions of wastewater sub-streams is effort-intensive and uncertain, with unclear effects on simulation improvement. Therefore, a simulation study was conducted, in which urine, grey water, black water, and brown water were subsequently separated from the inflow of a WWTP model. Two distinct fractionation scenarios were investigated: (i) purely load-related separation and (ii) load-related separation with individual COD fractionation. The results indicate that most trends in all source separation scenarios are comparable between both fractionation scenarios for most parameters. Only the COD effluent concentrations for grey water separation showed opposing trends. Differentiated fractionation impacts precipitant consumption in grey and brown water scenarios. Thus, a purely load-related approach suffices to identify the main benefits or operational challenges of source separation on WWTPs.