The proposed Mardie Project, which will use seawater and evaporation to produce raw salts for processing sulphate of potash, has been recommended for environmental approval by the Environmental Protection Authority (EPA) in Western Australia, subject to strict conditions.
Mardie Minerals Pty Ltd, a subsidiary of BCI Minerals Limited, proposes to transport the high-purity salt, fertiliser-grade sulphate of potash and other commercial by-products to a jetty in shallow waters and transfer by barge to bulk carriers at Pilbara Port Authority anchor points about 25km offshore.
The Mardie Project, located about 80km south-west of Karratha, expects annual production rates of 4 million tonnes of salt, 100 kilotonnes of sulphate of potash, and up to 300 kilotonnes of other salt products, sourced from 150 gigalitres of seawater.
EPA Chair Professor Matthew Tonts said the Authority has confidence in the proponent’s mitigation measures and offsets.
“The proponent has provided a management plan in accordance with the EPA’s framework for managing marine impacts, that demonstrates how marine quality will be managed and restricted to the area of impact predicted by the proponent’s modelling,” Professor Tonts said. “Management actions include dilution of brine prior to disposal and extensive monitoring of water quality.”
The proposal includes a seawater intake, evaporation ponds, processing plant, bitterns disposal pipeline and outfall, desalination plant, freshwater supply bores and associated infrastructure over a combined terrestrial and marine footprint.
The EPA noted that all future salt proposals between Exmouth Gulf and Karratha that had the potential to impact tidal samphire mudflats, algal mat and mangrove habitat, will also be required to consider cumulative impacts at a regional scale.
The EPA report and recommendations will be subject to a two-week appeal period until 21 July 2021. The Minister for Environment will make the final decision on the proposal.