A multinational corporation was allowed to pollute Canberra water with toxic chemicals in a case exposing more than a decade of failings by ACT authorities.
Koppers Wood Products' timber treatment plant in Hume caused hexavalent chromium, a carcinogen made infamous by environmental activist Erin Brockovich, to leach into groundwater at up to 2430 times the safe limit by 2007.
A Fairfax investigation has found the ACT government, despite knowing of the pollution, obtained no independent tests in the past seven years to ensure the carcinogens have not spread from the now mostly vacant 20-hectare site.
Records also reveal a string of missing groundwater monitoring results, which Koppers was legally required to submit to the government from at least 1998 until it closed the plant in 2005.
The contamination and the missing lab reports were noticed by the ACT Environment Protection Authority in 2005, when it first conducted a compliance check of Koppers' legally binding environmental authorisation, something it should have done annually from 2002.
The EPA has never taken any action against Koppers, despite the haphazard groundwater testing and the pollution at the site.
The revelations have outraged former ACT environment protection chief Bob Dunn, who worked on laws in the 1980s designed specifically to guard the region's waterways from the copper, chrome and arsenic Koppers used to treat timber.
Mr Dunn now believes it is an ''absolute certainty'' the company has breached criminal law. He has urged ACT authorities to launch an inquiry and to consider taking action against Koppers. ''I just can't believe it has actually happened,'' he said.
''Something has gone wrong somewhere, I believe it's clear. How can you say anything else?''
The contaminated water lies 1 kilometre uphill from a small tributary of Jerrabomberra Creek, which flows through the ecologically rich Jerrabomberra Wetlands and into Lake Burley Griffin.
The EPA remains confident the hexavalent chromium is isolated to a pocket of groundwater called a perched aquifer, and says it would be impossible for it to reach Jerrabomberra Creek.
Yet it has obtained no groundwater tests since 2007 to confirm the pollution has not shifted off-site, instead relying on the findings of a seven-year-old audit and an update provided by Koppers' consultants four years ago.
The lack of testing has attracted criticism from both the ACT Environmental Defenders' Office, a non-profit community legal centre, and Mr Dunn, who believes the pollution is likely to spread over time.
''They really should be doing periodic monitoring because there's no telling what might cause that to move off, to start moving around,'' Mr Dunn said.
''Monitoring is not that expensive, and I think what they're talking about is just an excuse.''
Koppers, through its Sydney office and Pittsburgh headquarters, has refused to respond to repeated requests for comment, saying only that it no longer owns the site.
The company first came to the ACT in the early 1980s to set up a treatment plant to produce Koppers logs, a wood product commonly used in gardens and playgrounds.
Activists, community groups, and politicians - led by former federal environment minister and then Canberra MP Ros Kelly - led a public campaign against the plant, fearing chemicals might leach into Jerrabomberra Creek and Lake Burley Griffin.
Koppers had already raised the ire of activists after arsenic was reportedly found at 40 times the safe limit in a street gutter outside another of its treatment plants near Bungendore. To alleviate the concerns, strict conditions were placed on Koppers' lease in Hume, while federal bureaucrats, led by Mr Dunn, introduced new environmental ordinances to protect the ACT in the period before self-government.
Bores were drilled deep into the land to monitor for groundwater pollution, and the lease required the company to send the results of independent lab tests to the federal government every three months. It is unclear whether those tests were ever received. Federal authorities say checking their archives would involve too much work.
But a former senior Koppers employee, who worked at the site in the late 1980s and early '90s, had no knowledge of the groundwater monitoring requirements when contacted earlier this month.
The deficient monitoring continued when federal laws were replaced with tough ACT legislation in 1997. EPA records show Koppers submitted just two groundwater test results in the three years between mid-2002 and 2005, when it was legally required to send them every three months, and just six batches in five years between 1998 and 2002, when it needed to send them every four months.
The EPA, which performed numerous site inspections and obtained tests of stormwater, soil and dam water, first reviewed the company's compliance with its legally binding 2002 environmental authorisation in 2005.
The review found ''no records of quarterly [groundwater] monitoring being undertaken'' and ''three soil locations and six water locations that contained concentrations of some contaminants above the relevant guidelines''.
Despite the finding, the EPA did not act against the company, reasoning that it was about to end production and planned to clean the soil and groundwater so the land could be sold.
The groundwater pollution was never dealt with.
A comprehensive independent audit of the site's soil was conducted in 2007, which warned the government and Koppers that groundwater pollution levels breached national limits.
It said the groundwater ''potentially poses human health and environmental risks if in contact'', and there was the ''potential for off-site migration'' in the future.
But the Environment and Sustainable Development Directorate's environmental protection and water regulation senior manager, Daniel Walters, said a specific audit of the groundwater had then been conducted, which alleviated those fears and gave authorities confidence the pollution would not spread.
''History dictates that none of us are perfect in the approaches that we've taken, but we do try to improve on where we were 10 or 15 years ago,'' he said. ''Our key parameter is to look after human health and the environment and all the advice we have on this site is that there's no risk in relation to that.''
Koppers Wood Products still operates plants in Bunbury, Grafton, Longford, Newcastle, and Takura, as well as in China, and the Philippines, according to its website. The company was later told a clean-up would cost more than $1 million, instead of the $100,000 first thought.
Koppers launched a lengthy battle in the ACT Supreme Court in 2007 against the site's new buyer, Canberra Hire Pty Ltd, arguing the sale contract absolved the polluter of any responsibility for the clean-up. It won the case late last year.
Canberra Hire is understood to be preparing more assessments of the polluted groundwater to see what action it must take.