ACT State of the Environment 2007

Indicator: Contaminated sites

Summary

Altogether, 754 potentially contaminated or confirmed contaminated sites have now been identified in the ACT, an increase of 86 sites from the previous reporting period.

During the reporting period a significant fuel leak at a service station caused soil and groundwater contamination in Chisholm. A major project was undertaken to remediate the site.

The National Environment Protection (Assessment of Site Contamination) Measure 1999 is under review.

What the results tell us about the ACT

Site assessment and remediation

Previous land uses in the ACT have resulted in land contamination at a number of sites. The identified activities associated with land contamination include former sheep dip sites, landfills, service stations, fuel depots and other hydrocarbon-affected sites.

Potentially contaminated sites are assessed in accordance with Environment Protection Authority endorsed guidelines, which include the National Environment Protection (Assessment of Site Contamination) Measure 1999. Confirmed contaminated sites cannot be used for other purposes until the site has been assessed, remediated if necessary, and certified by an independent auditor and/or by the Environment Protection Authority that the land is now suitable for the proposed or permitted land use.

The Environment Protection and Heritage Council is currently reviewing the National Environment Protection (Assessment of Site Contamination) Measure to ensure the latest national and international methodologies are incorporated (EPHC 2007).

Increase in potentially contaminated sites

By the end of the reporting period 754 potentially or confirmed contaminated sites had been identified in the ACT. This is an increase of 86 sites (11.4%) from the 668 sites reported in 2003 (OCE 2004). The increased number of sites includes 50 hydrocarbon sites, four additional service stations, 28 other sites (see below) and one historic site identified as a municipal landfill.

Groundwater contamination

Groundwater contamination needs ongoing management and/or monitoring at a number of sites in the ACT.

Groundwater is being monitored or remediated at three landfill sites (West Belconnen, Mugga Lane and Stromlo) and two other sites (chromium contamination and phenol contamination at Hume). Some bore data are available for the West Belconnen and Mugga Lane landfill sites which provide information on the physical, chemical and bacteriological properties of groundwater, as well as water table depth. The monitoring results of the Mugga Lane sites indicate no obvious chemical contaminants, with no hydrocarbons or pesticides and very low occurrences of heavy metals; however, some water contamination is indicated by the presence of faecal coliforms. The data also indicates the groundwater at these sites has a higher than average salinity range.

The activity primarily responsible for groundwater contamination in the ACT is underground fuel storage. Hydrocarbon plumes, both phase-separated and dissolved, are evident at 43 hydrocarbon sites in the ACT, the most publicised being the Civic Plume. The plumes are generally limited in extent and are confined to the shallower aquifers below the block where the fuel storage facilities were located. Sites containing phase-separated plumes (petrol product) are activity managed (remediated) using vacuum extraction and other means while sites containing dissolved phase plumes (petrol product dissolved in the water) are regularly monitored to ensure the groundwater does not pose a risk to human health or to the environment and is being naturally attenuated (remediated).

Service stations, fuel depots and hydrocarbon sites

In February 2005 a hole in one of the main underground fuel tanks at a Chisholm petrol station resulted in a significant amount – some 65,000 litres – of fuel leaking into the surrounding area. The fuel contaminated soil and perched groundwater1 around the site. Remediation of the on-site impacts took more than a year to complete due to the time taken to extract the hydrocarbons from the soil. Remediation of offsite impacts, including groundwater, is continuing and monitoring is ongoing.

As a result of the fuel spill at Chisholm the Environment Protection Authority has amended the Environment Protection Act 1997 to require that all service stations be licensed. Previously this has only been a requirement for fuel depots.

Altogether, 114 potentially contaminated service station sites have been identified in the ACT. This is an increase of four from the last reporting period; the total includes three new service stations and one previously non-identified site (Duntroon). Only 57 of these sites are operational; all others have been closed and the sites redeveloped or are subject to future redevelopment. Of the closed sites that have had assessment reports completed, the majority have groundwater contamination. Regular updates on the status of these sites are provided to the Environment Protection Authority. Based on the risk assessments undertaken at these sites they do not pose a risk to human health or to the environment. Sites that are found to pose a risk must be actively remediated and monitored.

The Canberra International Airport refuelling station has been added to the list of potentially contaminated fuel depot sites in the ACT, taking the total to six. Records show that there are also 137 other hydrocarbon sites that have been identified, an increase of 45 from the previous reporting period. These sites are not services stations; they are sites that have underground fuel storage tanks.

Municipal landfill

Identification of an historic landfill site from heritage records during the reporting period increased the number of potentially contaminated municipal landfill sites to 20. One commercial landfill is currently operating in the ACT at Mugga Lane.

Most of the landfill sites, with the exception of the Mugga Lane and West Belconnen sites, are not actively managed. If land use at the other landfill sites were changed (through, for example, development) the sites would need to be assessed and remediated to the standard required for the proposed land use.

Other sites

An additional 121 'other' potentially contaminated sites are known to exist in the ACT. Of these, 28 were identified during this reporting period. They include printers, sewage treatment works, unexploded ordinance sites and sites affected by acid leachate contamination.

In September 2005 the Environment Protection Authority ordered temporary closure of the Fairbairn Motorsports Park as dirt contaminated with asbestos had been used to build noise barriers. The facility was reopened following partial remediation subject to implementation of an Asbestos Management Plan.

Remediation

During the reporting period 61 sites were assessed and/or remediated. They comprised:

  • 34 hydrocarbon sites
  • nine spoil/landfill sites
  • 17 other sites
  • one sheep dip site.
  • All sites were found to be suitable for either their current permitted use, or proposed land uses under the Territory Plan. Statutory audits were conducted for 23 of these sites and the Environment Protection Authority audited the remainder. The statutory audits covered:
  • seven hydrocarbon sites: i.e. five service stations and two maintenance depots
  • three spoil/landfill sites: i.e. two at McKellar and one at Red Hill (Canberra Grammar Retirement Village)
  • one sheep dip site: i.e. at Forde (formerly known as Block 564 Gungahlin)
  • 12 other sites: i.e. eight that were part of the Kingston Foreshore Development, one at Mitchell Brickworks, two at Harrison (excluding sheep dip and Gungaderra Homestead sites), and one at the Defence (RAAF) site at Crace.

Site assessment and remediation

Potentially contaminated sites are assessed in accordance with guidelines endorsed by the EPA, which includes the National Environment Protection (Assessment of Site Contamination) Measure. Confirmed contaminated sites cannot be used for other purposes until the site has been assessed, remediated if necessary, and certified by an accredited independent auditor and/or the EPA that the land is now suitable for the proposed or permitted landuse.

The Assessment of Site Contamination Measure is currently under review by the National Environment Protection Council to ensure that the latest methodologies are incorporated from Australia and overseas (EPHC 2007).

Asbestos

In late 2004 an asbestos taskforce was established to report to the ACT Government on the extent and impact of asbestos in the ACT. The taskforce report, handed to the ACT Government in August 2005, made a number of recommendations, all of which the government accepted. The recommendations can be summarised into five areas, namely:

  • awareness and education
  • assessment and management
  • training
  • legislation
  • monitor and review.

The ACT Government has publicised the harmful effects of handling asbestos and has passed laws to ensure owners and managers of non-residential buildings deal with material containing asbestos in an appropriate way.

In the ACT, asbestos waste can be disposed of at two Environment Protection Authority authorised facilities, at Mugga Lane and West Belconnen Landfill. Waste containing asbestos is classified as industrial waste and must be handled in accordance with strict guidelines that set out how it must be packaged, transported and disposed of.

Waste containing asbestos is considered to be a controlled waste. Therefore, if the waste producer chooses to dispose of waste containing asbestos out of the Territory, its movement between the states and territories is covered under the Environment Protection Act 1997 and the National Environment Protection (Movement of Controlled Waste between States and Territories) Measure 1998.

Data sources and references

The Environment Protection Authority in the Department of Territory and Municipal Services supplied information about ACT potentially contaminated sites.

Extract from the Environment Protection Act 1997

4. Meaning of contaminated land
(1) In this Act:
contaminated, in relation to land, means the presence in, on or under the land, or a building or structure on the land, of a substance at a concentration above the concentration at which the substance is normally present in, on or under land, or a building or structure on land, in the same locality, if the presence causes, or is likely to cause either or both of the following:
(a) a risk of harm to human health;
(b) a risk of environmental harm.
(2) For subsection (1), land may be contaminated even if it became contaminated partly or entirely by the migration of contaminants into, onto or under the land from other land.
(3) However, land is not contaminated only because in any surface water standing or running on the land a substance is present in a concentration above the concentration at which the substance is normally present in, on or under land, or a building or structure on land, in the same locality.

Available at (viewed 12 February 2008).

EPHC (Environment Protection and Heritage Council) 2007, National Environment Protection (Assessment of Site Contamination) Measure 1999. Available at (viewed 20 November 2007)

OCE (Office of the Commissioner for the Environment) 2004, ACT State of the Environment Report 2003, March 2004

 
Notes

1 Perched groundwater is groundwater separated from another underlying body of groundwater by a confining layer, often clay or rock.

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