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Research article2020Peer reviewed

Failure of generic risk assessment model framework to predict groundwater pollution risk at hundreds of metal contaminated sites: Implications for research needs

Augustsson, A.; Soderberg, T. Uddh; Froberg, M.; Kleja, D. B. Berggren; Astrom, M.; Svensson, P. A.; Jarsjo, J.

Abstract

Soil pollution constitutes one of the major threats to public health, where spreading to groundwater is one of several critical aspects. In most internationally adopted frameworks for routine risk assessments of contaminated land, generic models and soil guideline values are cornerstones. In order to protect the groundwater at contaminated sites, a common practice worldwide today is to depart from health risk-based limit concentrations for groundwater, and use generic soil-to-groundwater spreading models to back-calculate corresponding equilibrium levels (concentration limits) in soil, which must not be exceeded at the site. This study presents an extensive survey of how actual soil and groundwater concentrations, compiled for all high-priority contaminated sites in Sweden, relate to the national model for risk management of contaminated sites, with focus on As, Cu, Pb and Zn. Results show that soil metal concentrations, as well as total amounts, constitute a poor basis for assessing groundwater contamination status. The evaluated model was essentially incapable of predicting groundwater contamination (i.e. concentrations above limit values) based on soil data, and erred on the "unsafe side" in a significant number of cases, with modelled correlations not being conservative enough. Further, the risk of groundwater contamination was almost entirely independent of industry type. In essence, since neither soil contaminant loads nor industry type is conclusive, there is a need for a supportive framework for assessing metal spreading to groundwater accounting for site-specific, geochemical conditions.

Keywords

Generic risk modelling; Contaminated sites; Groundwater pollution; Metals

Published in

Environmental Research
2020, Volume: 185, article number: 109252
Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE

    Sustainable Development Goals

    Ensure availability and sustainable management of water and sanitation for all
    Ensure healthy lives and promote well-being for all at all ages

    UKÄ Subject classification

    Environmental Management

    Publication identifier

    DOI: https://doi.org/10.1016/j.envres.2020.109252

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/105627