Contamination near suburb, FOI search reveals
By GREGG EASTON
The towers were originally part of the Belconnen Naval Transmitting Station. However, without fanfare, at approximately 4:00pm on December 20, 2006 all three towers crashed to the ground.
BNTS documents obtained under a Freedom of Information request to the Department of Defence have revealed its history, its contamination and the possible role it could play in Canberra’s environmental future.
From its introduction on April 20, 1939 the BNTS played a significant part in the defence of the Australian mainland during the tumultuous years of World War II. Formally known as HMAS Harman, the transmitting station also sent vital communications to RAN ships throughout the Korean and Vietnam conflicts and right up to their deployment in the Gulf.
It was also used to keep a waiting world in touch with the events of the 1956 Melbourne Olympic Games.
Following its decommissioning on June 1, 2005 the removal of the three towers was soon authorised by the then Minister for Environment and Heritage, Senator Ian Campbell. With the towers no longer operational and their retention deemed too costly for taxpayers, their removal was also considered the safest option as they continued to age and degrade.
At the height of its operation the BNTS also had 38 high frequency transmitters and 44 other types of antennae.
The BNTS site occupies 143ha of Commonwealth-owned land that makes up the northern section of Lawson, which is managed by the Department of Defence. It is Declared National Land, listed as an item of Commonwealth Heritage and has been a restricted area from 1939.
After Belconnen was declared a District in 1966, 24 of its 25 allocated suburbs have been developed. Lawson is its last remaining one and its largest parcel of undeveloped residential land. The remaining 137ha that makes up the southern section of Lawson is unleased Territory land.
Work is due to begin on the development of South Lawson in August. However, with the secrecy surrounding the Commonwealth owned land in North Lawson and the uncertainty of its future, residents of South Lawson will be left wondering what they’ll be living next to.
The assistant director of Gungahlin South for the ACT Land Development Agency, Stacey Quayle, says they have copies of the Department of Defence reports on the contamination of North Lawson.
“They indicate from the testing they’ve done near their boundary that there’s been no leeching of those contaminations into our site,” she said.
“We have as part of our design of the estate a buffer area which seeks to maintain the integrity.”
The FOI documents reveal those contaminants to include:
• PCBs (Polychlorinated Biphenyl) used in transformer oils;
• Dumping of materials, potentially including PCBs in the known landfill;
• The use of asbestos in building materials;
• Spills and leaks associated with four USTs (underground storage tanks); and two ASTs (aboveground storage tanks);
• Spills and leaks associated with the use of two chemical stores;
• Lead contamination of surface soils, associated with the use of lead paint; on aerials and buildings at the site;
• Demolition waste spread across the site;
• PAH (Polycyclic Aromatic Hydrocarbon) contamination associated with the incineration of materials; and
• Lead shot and the breakdown of lead and copper from a former pistol range.
An official contamination assessment of the decommissioned BNTS site was ordered by the Department of Defence in 2008. The independent professional engineering and development consultancy – SMEC was chosen for the task. SMEC has origins back to the massive Snowy Mountains Scheme in 1949.
The site was divided into twelve areas of concern for assessment including landfill, former staff accommodation, the USTs, the main building precinct, chemical storage sheds, the three 183m aerial masts, aerials and transformers, Ginninderra Creek/ Lake Ginninderra, the former pistol range and the remainder of the site.
A requirement of the contamination assessment was to assess concentrations against conservative low-density residential criteria set by the National Environment Protection Council.
Soil samples across the site exceeded the adopted assessment criteria for:
• Metal, asbestos and PCB contamination in landfill;
• Metal hotspots in surface soil near two transformers;
• Lead paint and lead contamination in surface soil where the three towers were dropped;
• Asbestos Containing Material (ACM) in former village;
• Petroleum Hydrocarbon in drainage lines down from main Transmitter building; and
• Fill material of demolition waste in drainage lines.
Impact to groundwater included elevated metals near landfill and dissolved phase petroleum hydrocarbons near USTs.
The reports recommended that any change of land use at the site would first have to undertake the following remedial activities to reduce ongoing liabilities including risk to human life and the environment.
• 6,000m3 of landfill
• Four underground storage tanks
• The transformers
• Fill from drainage lines
• Abandoned infrastructure
• Isolated hotspots in surface soils
The method used to remediate some of the site involved location, excavation, removal of contaminated soils, waste materials and the four USTs. The actual depth required to make it possible for all waste materials to be removed defined the excavation depth. The remediated areas were backfilled with clean soil imported to the site.
The former BNTS site is surplus to the needs of the Department of Defence which has embarked on mission of rehabilitating the land for future uses of different parts of the site. However, there are considerable environmental and heritage restraints at the site.
Peter Dowling, National Heritage Officer with the National Trust explains they’ve lobbied the government several times, all the way up to the Prime Minister for the site of the former aerial farm to be left for grasslands ecology studies.
“The BNTS site is prime residential land and some of it has been given over to future residents there,” he said.
“Those areas where the original Naval Staff residences were, we’re okay to see development going on in there as long as there is interpretation of the former Naval housing that was there.”
Following the release of its contamination report in April 2008, SMEC then set about determining an Environmental Management Plan for the site. It found a number of significant species and communities listed as threatened or endangered under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999.
Sections of the site are listed for its natural heritage as habitat for the endangered Golden Sun Moth. The site also contains the only known location of the threatened Ginninderra Peppercress, a small perennial herb. As a result no action may be taken that is likely to impact those species or ecological communities.
As the site has been a restricted area since 1939 its limited disturbance means the site contains significant ecological features. The majority of the site is likely to be retained and protected in its present condition, with the former staff village made available for the redevelopment
The Belconnen Naval Transmitting Station or “Bells” as it was affectionately known claimed its place at lonely Ginninderra Creek miles from anywhere and long before the district of Belconnen was even an idea. Slowly over 67 years urban development has caught up and surrounded it, but it refuses to be engulfed.