Development of soil ecotoxicity tests and their implementation in Australia and New Zealand

Abstract

The National Environment Protection Measure (NEPM) for Site Contamination (1999) and the Resource Management Act (1991) are the two pieces of legislation that govern the assessment and treatment of contaminated sites in Australia and New Zealand respectively. Both have incorporated the concepts of risk and sustainable management and encourage the use of chemical and biological data in the form of laboratory toxicity tests and direct toxicity assessment. The NEPM includes a set of human health and environmental investigation levels (EILs). If these are exceeded then either management action (in the form of remediation) or site-specific investigation (in the form of further chemical analyses and toxicity testing) is triggered. However, due to the lack of appropriate data only provisional EILs, based solely on phytoxicity data, could be developed. These are applied to all urban land but are really only valid for sandy loams with a pH of 6-8. Soil toxicity tests are required to assess site-specific impacts and to provide data that are used to derive EILs. The development of soil ecotoxicity tests has occurred only relatively recently in Australia and New Zealand (Australasia). It has lagged considerably behind developments in aquatic environments, both in terms of the number of phyla for which tests have been developed and the quantity of toxicity data available. Tests using earthworms, collembola, enchytraeids, isopods, plants and micro-organisms are now conducted in Australasia. However, the majority of these have used introduced rather than native species and the plant data is also heavily skewed to favour agricultural crops. In 2005, the NEPM will be reviewed and this provides an opportunity for many of the existing limitations to be addressed. This presentation will explain the relationship between soil toxicity tests, regulation and the management of contaminated sites in both Australia and New Zealand using several examples.