Hazmat Services has been appointed the contracts for Site Occupational Hygienist and Site Safety Officer for the remediation of the former Urunga Antimony Processing Plant by NSW Department of Industries – Lands (“DPI – Lands”). The project commenced in August 2015 and expected duration is up to 12 months.

 

The Project involves former location of an Antimony Processing Plant that was operated by ‘Broken Hill Antimony Pty Ltd’ and processed stibnite (antimony sulphide) ore mined from Wild Cattle Creek, Dorrigo from 1969 to 1974. The ore (containing impurities in the form of arsenic and mercury) was crushed and then passed through flotation cells to separate the precious metals from the rock waste. Tailings and mill wastewater were discharged onto the wetland foreshore area during the plant operations. A tailings deposit approximately one hectare in extent fans out into the adjoining wetland.

 

Chemicals used during the purification process included copper sulphate, sodium cyanide, lead nitrate, dextrin, sodium ethyl xanthate and crescylic acid. Watermill water was also contaminated with dissolved antimony and arsenic salts during treatment of the crushed ore. A gravel washery was also reported to be on-site, using water from the wetland (GHD, 2014).

 

In 1974, operations at the plant ceased due to the closure of mining production at Wild Cattle Creek. No clean-up operations or remedial work were undertaken when the Site was abandoned. In 2011 the NSW Environment Protection Authority sought to place a remediation order on the freehold owner of the Site. The owner was unable to fund the works and the ownership of the Site was transferred to DPI - Lands.

 

DPI - Lands engaged the Soil Conservation Service to project manage the detailed investigations of the Site and develop a Remedial Action Plan. The objective of the Remedial Action Plan is to achieve compliance with the Management Order and to remediate the Site so that it’s safe for public access without unacceptable risk to human health and minimise any further impact on the adjacent wetland.

 

In our role as the Site Occupational Hygienist, Hazmat has provided the Workplace Health & Safety Management Plan – Occupational Hygiene to support the remediation project and are providing Site inductions and daily monitoring of personnel and site conditions to assess exposure to the site contaminants of concern as well as providing personal protective equipment and facilities to support the workers at the site.