Groundwater pollution of biocides from facades in urban regions (GRUBURG)

The leaching of biocides from coatings for roofs and façades due to precipitation may cause pollution of stormwater runoff in urban areas and transfer of the active compounds into soil, groundwater and surface water. Various studies have shown that the emission of biocides and their transformation products at the building, the transfer pathway and the input into soil and groundwater are influenced by different factors. The present project will (1) develop an urban scenario for the worst-case assessment of biocide leaching from roofs and facades into groundwater, (2) compare the relevance of urban biocide inputs into groundwater with those of pesticides from agriculture, and (3) develop a practice-oriented, policy-based guideline for communities to avoid or reduce unintended substance inputs into groundwater. A broad review of relevant soil properties in urban areas will be compiled for the scenarios. Biocide emissions will be considered in relation to, for example, building geometry, exposure area and site-specific weather conditions. Representative surface types will be identified, that serve as entry for the substances to pass the soil and finally reach the groundwater. Here, partially sealed surfaces and structures of urban stormwater infiltration receive particular attention.The scenarios are subsequently analysed for their suitability in FOCUS models (PEARL, PELMO, etc.) by performing benchmark simulations. Finally, a suitable model is selected by comparing model results with those of groundwater simulations and existing field data. A literature survey will collect existing knowledge on pesticides and biocides in Germany and various European countries. For example, different active substances, entry routes (e.g. point and non-point sources) and end points of contamination (surface water, groundwater) will be distinguished. Refined and target-oriented measures at the source (source-control) and end-of-pipe will be proposed, scrutinized and included into an action guide for communities. An electronic decision support tool will also be provided.

Development of a façade protection system with reduced use of biocides and of a rainwater treatment installation using mixed absorbers for the reduction of substance emissions from urban areas into water bodies (SpuR).

In this project, two new types of technical measures are implemented to reduce emissions of substances from building materials into the environment. One at the source and one at end-of-pipe. In the measure at the source, the environmental impact of a new façade coating with fewer biocides compared to a conventional coating is investigated. The innovative coating system does not contain any slowly degradable algaecides used in conventional film protection. In the end-of-pipe measure, dissolved organic substances as well as particles and metals) are retained in a decentralised rainwater treatment plant with a new adsorber technology.

Emission-based product evaluation (EmBaPro)

The leaching of heavy metals, biocides and other additives can be relevant for the environmental impact of building products - and thus for their life cycle assessment. The aim of the project is to develop a standardised method for measuring and assessing pollutants from building materials over their entire life cycle. Possibilities and procedures are defined, how an extrapolation of the emissions from building is possible over the entire service life and with which scheme an integration of the products into labels is possible.

Leaching of metal surfaces and release into groundwater - literature research and measurements under consideration of three urban pesticides (MEDAUG)

Literature and groundwater data were reviewed and supplementary measurements were carried out for the leaching of copper and zinc surfaces and their input into groundwater by percolating rainwater. For groundwater, the pesticides Terbutryn, Diuron and Mecoprop used in buildings were also included.

Leaching tests for construction products: Modelling and implementation for the Blue Angel certificate

On the one hand, eluates from roofing membranes will be investigated in biotests with aquatic organisms in order to advance the identification of the leaching behaviour under the 'Blauer Engel' label. On the other hand, proposals for European emission and environmental exposure scenarios for model-based environmental assessment of building products will be developed and simulated with COMLEAM.

Building and Refurbishment as a Pollutant Source in the Urban Environment: Guidance for Regulation and Actors (BaSaR)

How substances from new construction and refurbishment areas are released into the aquatic environment is only known in part. Therefore, it is not possible to estimate the risks for soil and water in urban areas. With leaching tests in the laboratory, investigations at two sites in Berlin and modelling with COMLEAM, it is clarified from which building products relevant substance inputs reach soil and water via rainwater. The measures are intended to change sustainable construction and renovation over the use phase of the life cycle of a building in such a way that the requirements for groundwater and surface water in the urban environment are met.

Root-resistant bitumen membranes: Test and evaluation procedures for leaching

Chemical anti-rooting agents are used against the root penetration of bitumen membranes. In the presented project, a methodology was developed to estimate the possible pollution in precipitation water and to derive the need for treatment on the basis of simple, harmonised laboratory tests. The three defined pollution classes (low, medium, high) are based on the system for rainwater pollution according to the VSA guideline "Wastewater management in rainy weather".

Modelling the leaching of biocides from materials and environmental exposure with COMLEAM software (MODCOM)

In the project, COMLEAM is used to calculate leaching and water pollution using both a BPR-compliant procedure (ESDs) and dynamic simulation. For this purpose, BPR emission scenarios (urban and rural scenarios) were implemented in the software code for product type (PT) 7 to 10. In addition, automated reporting with the relevant results was integrated and simulation calculations for exemplary selected European sites for leaching and discharge into surface waters were implemented. An exposure analysis of the emissions in comparison with numerical requirements (exposure classification) and comparative statistical analysis of selected parameters to clarify the transferability of the model results (sensitivity analysis) complete the project.