Applicable site‐specific ecologicalrisk assessment of contaminated soils

The APPLICERA project will run from 2015 until 2018. It wasinitiated by the Swedish Transport Administration, researchersand consultants with decades of experience from riskassessment and risk management of contaminated soils.

Among the four protection targets identified in the Swedish riskassessment model for contaminated land (humans, surface,soil environment and ground-water), protection of the soilenvironment is often governing remediation goals. A vastmajority of contaminated sites are subjected to excavation,where all soil with contaminant levels above generic soilguideline values is removed, at high costs and with largelyunknown benefits for soil ecosystems.

Background

Aims

The SF-Box tool for PSQI

Applying the Triad

to develop a soil function based approach to assess soilecosystem effects / protection at contaminated sites

To develop a decision support tool that can be used toassess a potential soil quality index (PSQI) for contaminatedsoils sites (i.e. soil quality without contaminants), which canbe used to take decisions on whether it is meaningful or notto perform an ecological risk assessment.

To evaluate chemical, ecotoxicological and ecologicalmethods to be used in the soil quality Triad approach, interms of ecological relevance and soil function.

Chemical methods; total concentrations, bioavailableconcentrations (passive sampling for PAHs, isotopic dilution formetals; see http://projects.swedgeo.se/ibracs/).

Ecotoxicological methods; microtox, H4IIE-luc bioassay.

Ecological methods; abundance and diversity of micro-(nematodes), meso- (springtails and mites), and macro-fauna(earthworms), enzyme coding genes present in groups ofmicroorganisms in the N-cycles, multiple substrate-inducedrespiration.

For more information visit our webbsite: http://projects.swedgeo.se/APPLICERA

* Volchko, Y. et al. 2014. Using soil function evaluation in multi-criteria decision analysis for sustainability appraisal of remediation alternatives. Sci.Tot.Environ. 485:785-791

The soil quality Triad approach will be applied on soil from oneformer railway yard, mainly contaminated with polycyclic aromatichydrocarbons (PAHs), and on one on-going lysimeter study withsoils contaminated with PAHs and copper.

SQI Relevance to soil functionsFraction of coursematerial (> 2 mm)

Water infiltration, plant-available water and nutrient retention, aeration, root penetration.

Available watercapacity

Cycling of water in the soil. Water between the field capacity and the wilting point is the crucial factor of storing water in the soil for soil organisms between precipitations.

Organic C Cycling of carbon in the soil. Improved soil aggregate stability, water storage potential, nutrient cycling, and increased microbial diversity/ activity.

Organic C to N ratio Cycling of nitrogen in the soil. Indicator of the ability of microbial communities to supply plants with nitrogen.

pH Affecting the solubility of many toxic elements and nutrient availability.

Total or plant available P

Phosphorus cycling. Macronutrient for plants and a measure of soil fertility.

Table 1. Proposed soil quality indicators used for determination ofpotential soil quality index (SQI) (Volchko et al., 2014*).

The Triad approach

Figure 1. The principles of the SF-Box tool (Volchko et al., 2014*).Proposed soil quality indicators are given in Table 1.

Figure 2. In the Triad approach for ecological risk assessment resultsfrom three lines of evidence are being combined into one measure.

Dan B. Kleja1, Pär‐Erik Back1, Anja Enell1, Magnus Engwall3, Malin Fransson4, Sara Hallin2, Christopher Jones2, Maria Larsson3, Lars Rosén5, Astrid Taylor2, Jana Weiss2, Maria Viketoft2, Yevheniya Volchko5, Annika Åberg1 and Karin Wiberg2; 1 Swedish Geotechnical Institute (SGI), Sweden; 2 Swedish University of Agricultural Sciences (SLU), Sweden; 3 Örebro University, Sweden; 4 Swedish Transport Administration, Sweden; 5 Chalmers University of Technology, Sweden