The EPA has conducted water quality monitoring in Okehampton Bay and the Mercury Passage since August 2017. The monitoring program aims to increase the understanding of water quality within the Mercury Passage and Okehampton Bay.
Water Quality Monitoring Program
The purpose of the program is to provide
- water quality information to increase the understanding of water quality in the Mercury Passage and Okehampton Bay.
- water quality information for comparison with Default Guideline Values (DGVs) for aquatic ecosystems for the Mercury Passage.
- water quality information to assist nutrient dispersion modelling and biogeochemical model development and validation.
- independent validation of water quality information collected by (or on behalf of) Tassal, for the initial 2 years of operation.
Default Guideline Values (DGVs) for aquatic ecosystems
Default Guideline Values (DGVs) for aquatic ecosystems have been derived for the Mercury Passage and Okehampton Bay Area. The available data from August 2014 to July 2017 has allowed for the derivation of annual and seasonal DGVs of surface, 5 metre depth, integrated depth, and bottom waters for key indicators. For dissolved oxygen, temperature, and pH the 20th percentile represents the lower DGV and the 80th percentile the upper DGV, whilst for all other indicators the 80th percentile represents the DGV. The DGVs are based on the Oil Spill Response Area (OSRA) segments and provide a level of refinement over the interim Default guideline values for Coastal and Marine waters based on the IMCRA bioregion.
DGVs for Aquatic Ecosystems - OSRA section 72 (PDF 644Kb)
Monitoring Results