Lurking beneath the world’s most liveable city!
Have you ever wondered what’s creeping around under your feet and the layers of concrete across the city? Probably not a lot. But the fact is many stories of Melbourne’s history lie here. The city’s industrial past has left a hidden legacy – pollution.
Melbourne wasn’t always your coffee crazed, culturally savvy, hot pot it is today. The city was literally built on dirty work. Ports, factories, manufacturers, agriculture; Melbourne’s forefathers had their hands dirty building up this young nation.
Today, as more people want to live in this great city, old industrial sites (whether shut down or still operating) are moving on out, leaving redevelopers with problematic parcels of land that require testing and cleaning up before it can be deemed safe for residential purposes. This is all easier said than done, and the state has learnt lessons via some messy business in the past. However, with the scale of this issue, Victoria has lead the way with some pretty nifty policy frameworks to ensure the environment and human health are appropriately managed for future generations.
One of the major challenges with underground pollution (or contaminated land), is the difficulty to extract it. And contamination not only sits in the soil, but it makes its way into groundwater which means it becomes mobile. Very rarely is it visible or obvious to our ‘naked’ senses, but sometimes can be detected though colouration, smell or distressed vegetation. More often than not, contaminated land is invisible and only confirmed through testing samples taken at the site. If test results uncover concentrations of metals and chemicals exceeding regulation, that is, safe limits, then contamination is deemed present.
Every city has its contamination issues, and states vary with their level of information and registers available to the public on where these sites may lie. The number of contaminated sites in Victoria is currently unknown. The last comprehensive desktop assessment in 1997 estimated there were around 10 000 contaminated sites – a figure grossly underestimated one would assume.
Assessing risk from contaminated sites involves a mix of scientific and planning questions and answers. In a number of well publicised cases, rezoning of land for residential sub-division has resulted in the potential exposure of people (particularly children) to unacceptable risks by chemical contaminants. These cases have highlighted the need for systems to identify and ensure the proper management of contaminated land.
History of explosives factories: plans exist for a multibillion-dollar development at a former munitions factory site in Maribyrnong, another of many across Victoria. After almost a century of explosives production, about 25 per cent of the 128 hectare site is contaminated – both soil and groundwater. The clean-up of the Maribyrnong site – planned to accommodate 3000 homes – commenced a few years ago and could take another five more years, costing up to $300 million. Albion Explosives Factory is another similar site, now Cairnlea housing estate.
Costs of remediation can be enormous, but the price to not clean-up has shown to far outweigh the initial costs – financially, socially and environmentally. In the late 1980s, heavily contaminated soil was uncovered during redevelopment of a former lead smelter and battery factory at Ardeer. Sampling revealed lead concentrations at 264,000 mg/kg (nearly 1000 times the investigation level for residential purposes). As such, eight new houses were demolished to allow for clean up works and relocation occurred for the families who recently moved in. This generated untold social and emotional costs to the local community and a huge financial burden to the government.
Contamination is not only confined to old industrial sites – anywhere chemicals or wastes were handled and stored could be potentially dangerous. Agricultural land can often be a big culprit. Ie. The historic and notoriously toxic sheep and cattle dips. Even where historical land contamination is identified and managed prior to redevelopment, costs can be sky high. Clean up of a service station can range from tens of thousands of dollars up to millions depending on the nature and extent of contamination.
So before you go growing that veggie patch in the backyard, maybe first check of the historic land use in your neighbourhood…
You can check out if a parcel of land near you is potentially contaminated by contacting your local government or EPA Victoria.