The Environment Protection Authority (EPA) is currently investigating a chemical spill at the Henty gold mine north of Queenstown on Tasmania’s west coast.
EPA Director Alex Schaap said it appears that a portable container was accidently pierced yesterday afternoon and up to 800 litres of a flocculating agent may have entered the Henty River above Lake Henty.
“Flocculating agents are generally very safe and are commonly used to settle out suspended solids in drinking water treatment plants but this particular chemical was intended for industrial use and contains an ingredient which is quite toxic to fish at higher concentrations,” Mr. Schaap said.
“The chemical is rated as a low risk to human health and so the focus of the response has been to minimise the risk to the environment.”
“Sampling is continuing and analytical results are not yet available but the highest concentrations would have been experienced at Lake Henty and immediately upstream. No ill effects have been observed but observations will continue over the coming days.”
Mr. Schaap said the area has been experiencing high rainfall and there have been heavy flows into Lake Henty with discharge from the lake through a canal to Lake Plimsoll and over the spill way into the Henty River.
“The subsequent dilutions in both cases are calculated to be sufficiently large to reduce pollutant concentrations to acceptable levels,” Mr. Schaap said.
“Consultation with Population Health Services concluded that as a result of this dilution the incident poses no risk to human health in the sparsely populated downstream areas.”