SoE 2006 > Land > 4.6 Chemical contamination: land

4.6 Chemical contamination: land

Steady progress has been made with the remediation of known contaminated land sites. However, the off-site movement of chemicals from contaminated sites has caused long-lasting impacts, including the contamination of waterways, which will take many years to remediate.

Severe degradation has already occurred in some areas due to industrial legacies and it is probable that ongoing identification of past contamination will continue to expand the size of the known problem.

The regulatory regime in NSW is well established, and the identification, assessment and remediation of those contaminated sites determined to be of significant risk of harm under the Contaminated Land Management Act 1997 has mostly progressed well. Of sites listed under this Act, the proportion remediated has risen from 13% in 2002 to 25% in 2006. The economic costs associated with remediation remain high.

Information on the remediation of contaminated sites under the planning and development control process is held by individual councils and is not collected centrally.

NSW indicators

Introduction

Some recent and historical land-use activities have resulted in the contamination of land and waterways by hazardous chemicals and wastes. Land contamination can have significant environmental, social and economic consequences, including the degradation of groundwater, surface waters and sediments; contaminant uptake by plants and animals; and potential human exposure to contamination.

For example, the operation of the former ICI facility (Orica Industrial Park) on the Botany Sands Aquifer has led to the contamination of this important aquifer and has prevented residents and industry from using large areas of the groundwater resource. The contaminated groundwater is being remediated at significant cost.

Contamination can spread, affecting other areas, water resources and dependent biota. For example, in February 2006, the government prohibited all commercial fishing in Port Jackson (Sydney Harbour) and its tributaries until 2011 because elevated levels of dioxin had been detected in finfish and prawns. This has had economic effects on the livelihood of commercial fishers who previously used Sydney Harbour as a fishing ground. The dioxin contamination in Sydney Harbour is considered primarily to result from the production of herbicides and other chemicals in Rhodes, adjacent to Homebush Bay, and the placement of waste materials at two sites on the Rhodes Peninsula between 1949 and 1976. The estimated cost of remediating Homebush Bay and adjacent land is estimated to be $120 million. In 1997 the NSW Government committed $21 million for the removal and destruction of contamination from parts of the bay, and a commercial venture is contributing approximately $100 million towards the land remediation (see Water 5.7).

Contamination of land can reduce land value and restrict the suitability of the land for more sensitive land uses. Remediation may be required to make the land suitable for its proposed use, a process that is often expensive and can take many years from initial investigation to final validation.

Current status and trends

Contaminated sites in NSW continue to be discovered, as the problem is often not apparent until there is a change in land use, or the site is prepared for sale or redevelopment. Sites posing a 'significant risk of harm' (contaminated land with potential for immediate or long-term adverse effects on human health and the environment) are regulated by the Government under the Contaminated Land Management Act 1997 (CLM Act). These include sites with notices issued under sections 35 and 36 of the Environmentally Hazardous Chemicals Act 1985 (EHC Act). If the contamination present on a site is posing a significant risk of harm, the site owner and the polluter are obliged to notify the Government who will determine whether the site's contamination warrants its regulation. The number of sites notified to the Government is relatively constant, at about 35 sites per year. The number of contaminated sites regulated under the CLM Act and the EHC Act continues to grow, from 148 in June 2002 to 247 in June 2006. In the same period the number of remediated sites has increased from 47 to 77 (Figure 4.1).

Figure 4.1: Progress with remediation of sites regulated under the CLM and EHC Acts

Source: DEC data 2006

The majority of contaminated sites are not considered to pose a significant risk to human health or the environment. These are managed by local councils through the planning and development control process. In such cases, the contamination status of a site is assessed when it is proposed to develop the land for a more sensitive land use. The number of contaminated sites managed through the planning process is unknown. There is no systematic process for collecting information for sites managed by local councils.

Known contaminated sites tend to be clustered in areas that have been centres of heavy industry or transport hubs, such as Newcastle, Wollongong and south-eastern and mid-western Sydney, or sites of chemically intensive agricultural activities, such as cattle-tick dip sites in north-eastern NSW. For example 65% of sites assessed under the CLM Act are related to petrol stations, landfill sites, chemical industries or gasworks. Nonetheless, contamination may also occur in many other areas. Table 4.3 lists the land uses of sites currently regulated under the CLM Act and the contaminants typically associated with these sites. There is also a significant legacy of derelict mines in NSW.

Table 4.3: The types of land uses of sites currently regulated under the CLM Act in NSW

Source: DEC data November 2005

Notes: Some sites have had more than one former land use and not all previous uses are known. These include all sites where the contamination has been determined to pose a significant risk of harm under the CLM Act.

Response to the issue

The remediation of contaminated sites is a slow, complicated and expensive process that can take many years to complete. The prevention of contamination through pollution control is therefore important. The Protection of the Environment Operations Act 1997 (POEO Act) controls the operation of polluting activities to ensure that the environment is protected. Controls on the use of agricultural chemicals under the Pesticides Act 1999, and the organised collection and disposal of unwanted agricultural chemicals – such as ChemCollect, a program funded by state, territory and Commonwealth governments between 1999 and 2002, and ChemClear, a current industry-funded initiative – help ensure that practices leading to contamination are minimised.

Where contamination presents a significant risk of harm to either human health or the environment, it is controlled under the CLM Act. The Act applies the polluter-pays principle and establishes a process for investigating and, where appropriate, remediating contaminated sites. The Act empowers the EPA to issue declarations, orders or voluntary agreements to investigate or remediate a seriously contaminated area or site.

State Environmental Planning Policy No.55: Remediation of Land (SEPP 55) requires consent authorities to consider contaminated sites matters when rezoning land or assessing development applications. Many keep records of premises that may have been associated with contamination activities such as the storage, manufacture and/or use of hazardous chemicals and toxic wastes.

The current arrangements provide an effective framework for responding to contamination of sites once they are identified.

There are a number of Government programs that are focused on the remediation of contaminated sites. The Environmental Trust's Contaminated Land Management Program approved grants of approximately $4 million, between 2001–02 and 2005–06, to assist with the remediation of contaminated sites.

The Derelict Mines Program administered by the Government allocates funds for the rehabilitation of disused mines. As at November 2005, there were 570 derelict mines being managed under this program. The program aims to ensure that derelict mine sites do not pose an unacceptable hazard to human health and the environment, while managing sources of site contamination and addressing offsite contaminant migration.

Future directions

Continued State and local government cooperation will be needed to ensure contaminated sites are adequately identified, appropriately regulated with respect to the risk of the contamination, and satisfactorily remediated to ensure the land is suitable for the proposed land uses. Due to the introduction of stronger environmental legislation and the licensing of industrial activities, it is unlikely that the number of new contaminated sites being created will increase dramatically. However, the prevention of new contamination requires continued vigilance by the operators and regulators of activities that may cause contamination of land. SEPP 55 continues to play a key role in preventing contaminated land from being used for a more sensitive land use without appropriate investigation and, if required, remediation.

Remediation of existing sites will ultimately reduce the number of DEC-regulated sites, although it is likely that more sites remain to be identified. The most significant class of ongoing legacy sites (in both number and degree) is derelict mines.

Data on contaminated sites managed through the planning and development approval process is held by individual councils and is not coordinated by a central agency. Data collation is needed on all contaminated sites managed through local governments or State agencies to allow full reporting on the state of the environment in NSW.