Client name: Nyrstar Hobart Pty Ltd

Duration: August 2015 - October 2015

Location: Hobart, Tasmania, Australia

Our team developed an effective groundwater monitoring and characterisation plan to identify remediation options for a large scale zinc smelter.

Situation

The Nyrstar Hobart smelter is located at Lutana on the Derwent River, between Prince of Wales Bay and New Town Bay.

Operations at the smelter site over the last 100 years have resulted in groundwater contamination across approximately 90ha. Nyrstar places a heavy emphasis on the recovery of contaminated groundwater and subsequent on-site treatment in order to reduce migration of contaminants to the Derwent estuary.

In order to fill data gaps, and in line with improving environmental outcomes for the facility, Nyrstar installed 15 groundwater wells along the foreshore area to complement the existing bore network.

An inspection and well redevelopment program was also undertaken across the entire well network to improve well functionality and useability and to increase data capture and reliability across the entire site. 

We were asked to complete monitoring and aquifer testing of the recently installed groundwater wells to characterise groundwater conditions and identify potential options for groundwater remediation.  

Solution

Coffey undertook an investigation of all accessible groundwater monitoring wells across the site to improve the usability of the monitoring network.

We also developed a groundwater monitoring plan to align the monitoring of the recently installed wells with the site Environment Protection Notice, the site groundwater management strategy and the current monitoring methodologies employed at the site. 

Our work also included groundwater level measurement, groundwater sampling and aquifer testing of the recently installed groundwater monitoring wells along the foreshore of the facility.

Result

The groundwater monitoring and characterisation project confirmed hydrogeological processes, interaction with surface water systems, identified sources of metal contamination and preferential contaminant pathways.

Based on the results of the assessment remediation options were identified and feasibility level costing provided.