THE Camden Haven made national headlines for the wrong reasons with a potential radioactive scare on the Pacific Highway.
An unusual clay substance was uncovered at the site of the Herons Creek to Stills Road upgrade of the highway three weeks ago.
Exposure to the clay caused five workers to fall ill with vomiting and nausea.
The workers have since been tested for exposure to radiation, when it was initially thought to have been a radioactive substance. Thirteen other workers were tested but did not show symptoms.
The five have since recovered and reported back to work.
Tests of the odorous clay have ruled out chemical and radioactive contamination. Tests by the Roads and Maritime Services were negative for pesticides, polyaromatic hydrocarbons, polychlorinated biphenyls or any of the volatile organic hydrocarbons.
It did test positive for acid sulphate soils potential.
Further testing will determine what the odour given off and the clay itself, which turns orange as it oxidises with the air, may be.
The cause of the workers’ illness was feared to be the 1980 crash which occurred when a semi trailer was hit by a panel van. The truck rolled and spilled its load of drums containing radioactive material, Chinese food, and the now banned insecticide DDT.
The drums’ exterior was damaged but the lead canisters housing the radioactive substances were intact, so leakage was ruled out.
At the time of the accident, it was reported that the drums were removed but the DDT and the food preservative sodium propionate was buried on the site. DDT has been banned in Australia since 1987.
Soil testing was undertaken on the upgrade site every 100m prior to work beginning.
“The scope of pre-upgrade work included the remediation of the site where material was buried after the crash in 1980 involving a truck carrying mixed waste including radioactive material,” states the RMS website.
“Field notes from 5 April 2011 described the buried material as containing food packaging waste described as soy drink, dried shrimp paste and food cans.
“No containers or drums indicating industrial type waste were observed.
“The buried material was excavated and placed in a temporary stockpile pending its removal from site and proper disposal by BMD.
“RMS' contractor BMD Constructions have carried out further investigations and their consultant Coffey Geosciences issued a report on 14 April 2011 that validated the site and classified the material as inert waste and it was disposed at a licenced landfill.”
A geotechnical expert from Hackett Laboratory Services said it was common practice to bury any material not considered dangerous, during the clean up of an accident. During the 1980s the highway was a winding track where accidents happened frequently.
An exclusion zone was set up around the site recently as NSW Fire and Rescue dealt with the hazardous substance.
Investigations are continuing.