The PROMISCES project aims to develop innovative, systemic solutions to protect health, environment, and natural resources from persistent, mobile and potentially toxic (PM(T)) substances by addressing regulatory gaps and promoting circular economy principles. This deliverable, in particular seeks to:

· Identify inconsistencies, gaps, and challenges within the existing EU legal and policy framework related to PM(T) substances.

· Promote harmonized regulatory approaches across environmental compartments.

· Provide EU and national policymakers with actionable, evidence-based policy recommendations to improve the management of PMT(s) in the soil-sediment-water system (and beyond).

· Emphasize that updated policy approaches address disparities and technical, financial and social challenges across Member States (MS).

The "Toolbox Fate & Transport Modelling of PMTs in the Environment" is a key deliverable from the H2020 PROMISCES project. This toolbox is a demonstrator that includes a collection of models developed in the PROMISCES project which are designed to assess the fate and transport of persistent, mobile, and toxic substances (PMTs) across various scales (local, regional) and conditions (e.g., urban run-off, bank filtration, unsaturated zone, groundwater).
This toolbox presents the basic information with links to the software and model input files with which the models can be run. This deliverable is intended for qualified modellers. It is complementary with the Guidance document, deliverable D2.4 (Zessner et al., 2025) which describes how to apply modelling tools in a tiered way as part of predictive risk assessment.

The scope of this document, produced as part of the H2020 PROMISCES project, is to provide guidance for applications of models with a specific focus on model trains for the assessment of exposure to PMTs as part of the predictive risk assessment related to surface and groundwater. This document explains the basic concepts of specific models and how best to use them in model
trains in the framework of a tiered approach. The intention is to inform users and interested stakeholders about what needs to be considered when using different methods, what is the best use of specific models, what are the best combinations in model trains and what are their current limitations.

The Horizon 2020 project PROMISCES aims to increase the circularity of resources by overcoming barriers associated with the presence of PM(T)s in the soil-sediment-water system.

This deliverable provides guidance on how to co-create a solution strategy for dealing with PM(T)(s) in a circular economy. For this, we have used the experience and lessons learnt in the co-creation workshops organized within the PROMISCES project.