Reuse and recycle--considering the soil below constructions

Abstract

The European Construction Products Regulation provides a life cycle based framework for the environmental assessment of construction products. Harmonised European standards for the assessment of the release of dangerous substances and for declaration of environmental performance are in progress. Risk based limit values for the protection of soil and groundwater below construction works will still bet set nationally. In this paper we review the possibilities to expand the ongoing harmonisation to include risk assessment and life cycle assessment (LCA). Based on reviews of national European limit value models (LMVs) for assessment of release to soil and groundwater, two areas for harmonisation emerge: 1- The toxicological criteria. Toxicological endpoints to protect human health and environment are similar, and data from the same toxicological data sets are used to establish acceptance criteria. 2- The emission part of LMVs. We extracted six generic construction works for granular materials. These encompass the most common choices and span the different release scenarios applied. Harmonised emission models would also facilitate LCA and environmental product declaration (EPD). The immission or transport part of the LVMs is less promising for harmonisation. Locating the acceptance criteria point of compliance close to the construction works is advantageous from many aspects and would facilitate harmonisation of assessments. We have identified two different strategies to include recycling in the assessments: 1- Tiered procedure where assessment and declaration of performance are made for the intended primary use of the product only and renewed assessments are made whenever the construction works are demolished and the product is recovered. 2- Scenario based procedure where future recycling scenarios, into new products and construction works, are forecasted. In this case the initial assessment and declaration of environmental performance of a construction product is performed both for the intended primary use of the product and for the recycling scenarios.

Keywords: Construction products; Contamination; Environmental criteria; Environmental product declaration EPD; Life cycle assessment LCA; Natural resources.