Land Theme Report
Australia State of the Environment Report 2001 (Theme Report)
Prepared by: Ann Hamblin, Bureau of Rural Sciences, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06748 5
Soil and land pollution (continued)
Pressure
Total immobile contaminant loads across major regions [L Indicator 6.1]
The total contaminant load occurring across different types of land use and industry activity in Australia is not known. The total number of sites was estimated at 80 000 (NEPC 1999a) with 30 000 each in NSW and Victoria. Despite their relatively small areas, even Tasmania and the ACT were estimated to contain 500 sites each. For more detail see the Human Settlements Theme Report. These are relatively small figures compared with the 1.5 million highly contaminated sites identified in the USA, but nevertheless represent a significant potential hazard to health and the environment (Naidu et al. 1998). While currently operating installations are increasingly regulated and monitored (see Scheduled wastes), the safe management of closed and abandoned sites is a significant environmental challenge. Such sites include agricultural dip-sites where arsenic and organochlorine products were used, old metal smelting sites (especially copper and lead), and 'orphan sites', under disputed ownership in cities, such as closed tips, gas plants, garages, and power stations where buried hydrocarbons (in tanks) and heavy metals occur.
Contaminants can be classified in various ways. The National Pollutant Inventory classifies by chemical substance, industry, emission destination (air, water, land) and location. Amounts of emissions are being measured at 1200 sites for 23 of the categories of industry out of a total 90 categories of industry that will eventually be monitored. During the past two years, standard protocols for monitoring and reporting have been developed for 78 industry handbooks, including the 23 that are currently contributing emissions data. To date the inventory has excluded all dispersed contaminant loads, such as those that occur through extensive aerial application in agriculture and forestry, and small-scale emitters of industrial wastes.
| Chemical type (substance) | Industry (facility) A | Location |
|---|---|---|
| Heavy metals | Petroleum industry | Catchment/air shed |
| Hydrocarbons | Mineral mining | National |
| Mineral salts | Mineral smelting | State or Territory |
| Particulates | Petrochemicals | Local government |
| Oxides of N, S, C | Chemical manufacture | Town |
| Organic acids, ketones | Manufacturing (paints) | |
| Manufacturing (metals) | ||
| Processing (food, fibre) | ||
| Processing (pulp, paper) |
A 23 of 80 listed to date.
Source: Environment Australia (2001).
The database is set up so that information on the chemistry of substances, methods used to obtain the emissions data for each substance, and organisation and company details are reported publicly. The database will in time become an invaluable resource for environmental and human health assessment.
Scheduled wastes are wastes that are:
- organic in nature,
- resistant to degradation by chemical, physical or biological means,
- toxic to humans, vegetation or aquatic life; accumulate in humans, flora and fauna and are likely to be carcinogenic or mutagenic,
- intractable or impossible to dispose of without specialised facilities or technologies.
Those prescribed are:
- hexachlorobenzene, produced from the production of carbon tetrachloride by ICI at Botany Bay, NSW,
- polychlorinated biphenyls (PCBs), used as coolants in electrical equipment,
- organochlorine pesticides (OCs): 18 compounds including DDT and dieldrin,
- other chlorinated hydrocarbons.
Use of these chemicals is now banned, or being phased out, but the disposal of current stocks and wastes will be an on-going issue for some time. A national approach to their disposal has been developed in stages, as part of the Australian and New Zealand Environment and Conservation Council's (ANZECC) National Strategy for the Management of Scheduled Waste. One example is ChemCollect, which is a nationally coordinated, free collection scheme to ensure that unwanted and de-registered agricultural and veterinary chemicals, particularly organo-chlorines and phosphates, are safely collected from rural areas and destroyed in a socially and environmentally acceptable manner. ChemCollect is a three-year program undertaken by states, with funding shared between states and commonwealth. It is estimated that ChemCollect will result in the safe disposal of up to 1300 tonnes of hazardous chemicals.
To ensure stocks do not build up again after the program is completed, the agricultural industries have agreed to institute ChemClear, an ongoing program of regular collections of unused, registered farm chemicals which are otherwise non-returnable. Another program to reduce waste in the agricultural sector is drumMUSTER (see later in this section; also http://www.ea.gov.au/industry/chemicals/swm/review.html).
Implications
The past five years has been one of substantial government activity in introducing a coordinated regulatory framework in all jurisdictions for the management of pollutants and contaminants that may be hazardous either to human health or the environment. It is too early to say whether this regulatory and monitoring activity is as yet being translated into a reduction in contaminant pressure on the environment. What is now possible is to get a balanced and comprehensive view of where the major point source pressures exist. The diffuse source pressures are less well defined, but are most likely to be associated with rural activities.