Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:5:p6
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 5 (pt 6/10)
Character Range: 1455440–1458527

have been exceeded, the ordinance (BBodSchV 1999) provides additional annual loading limits of the contaminants to prevent the soil concentration reaching the trigger or action values and causing adverse effects.

Trigger values trigger the investigation of the contaminated site to ascertain if the contaminant poses a hazard. Action values represent a direct hazard situation which should be prevented and therefore soils exceeding action values should be remediated. Action and trigger values are land use-dependent and specific exposure pathways are assigned to each land use. Trigger and action values are developed for three exposure pathways: soil to human, soil to plant and soil to groundwater. Trigger values for inorganic contaminants and the soil to plant pathway are, if possible, based on an estimate of the bioavailable concentration (that is, measured in 1 M NH4NO3 soil extraction). The soil to plant values are based on regression analyses between soil and plant concentrations of the contaminant. A maximum internal plant concentration is set, either based on human health issues or plant toxicity, and the corresponding soil concentration, based on the linear regression, is the trigger or action value.

5.1.6         A6: New Zealand
The New Zealand Ministry for the Environment has developed environmental guideline values (EGVs) for contaminated land assessment, which are available online at
www.mfe.govt.nz/publications/hazardous/contaminated-land-mgmt-guidelines-no2/
contaminated-land-mgmt-guidelines-no2.pdf. The contaminated land management guidelines are not regulations but a guideline to obtain the most appropriate EGVs for a contaminated site.

New Zealand EGVs contain values with some derived within New Zealand and others by international regulators (for example, Canada, the Netherlands, USA, Australia). Therefore, a suite of methods was used to derive these values. A distinction was made between risk-based and threshold-based EGVs which is based on quality and quantity of the data available and the method used to derive the values.

Risk-based values are derived from a given exposure scenario; for example, protection of human health or the protection of a nominal proportion of species in an ecosystem and thus are calculated using a SSD method.

Threshold values may be derived from toxicological data where insufficient data is available to calculate risk-based values. The EGVs may also be classified as threshold values where insufficient information on their derivation is provided.

A hierarchy was established to determine the order in which EGVs should be used in a contaminated site assessment. The hierarchy in descending order of use is:
    1. New Zealand-derived risk-based EGVs
    2. risk-based EGVs from other national regulators
    3. New Zealand-derived threshold EGVs
    4. threshold EGVs from other national regulators.

Although EGVs are provided, the New Zealand framework stresses that the original reference document for an EGV must be referred to in order to assess if the EGV is relevant for the contaminated soil