The pulp mill will release waste water into the sea 23 km north east of the mill site near Five Mile Bluff. This aspect of the project required Commonwealth Government approval in order to ensure the environmental impacts of the mill were acceptable, the Minister required Gunns to complete a research project on the interactions between the pulp mill effluent and the marine environment. This $5 million study took two years to complete.
The Government was advised by an Independent Expert Group, which reviewed the marine modelling work and scientific studies commissioned by Gunns under the project’s environmental impact management plan.
The project has been stringently assessed by the Commonwealth Government under the Environment Protection and Biodiversity Conservation Act, 1999. In March 2011, the Minister issued final approvals covering all aspects of the project subject to the Act.
The Commonwealth approvals set strict limits on the allowable levels of discharge that can be released by the mill. They also require Gunns to implement strategies to monitor the impacts of the mill discharge on the marine environment, as well as putting in place strict response measures that may be triggered in response to the ongoing findings of the monitoring program.
The hydrodynamic research project found that the key marine toxicant of concern, chlorate, will readily meet its dilution targets and poses a very low ecological risk to Commonwealth marine areas and elsewhere.
The project’s environmental monitoring regime includes numerous measures to ensure the marine environment is protected, including:
- Continuous monitoring of mill effluent for volume and a number of key pollutants
- Sampling and laboratory analysis of mill effluent
- Monitoring of any changes of abundance or diversity of marine flora and fauna that inhabit soft sediments and rocky reefs
- Baseline and ongoing monitoring of marine water quality
- Sampling and analysis of marine sediments at sites near to and distant from the outfall
- A marine sentinel program involving examining tissue concentrations of a range of pollutants in shellfish, fish and penguin eggs, and
- Surveillance of general water quality and underwater noise in the Tamar River estuary during mill construction.