WATER SHARING PLAN FOR THE NSW GREAT ARTESIAN BASIN
GROUNDWATER SOURCES
Groundwater Resource Description
NSW Great Artesian Basin
February 2020

Executive Summary This report and field study was produced as a result of the comments in the Santos 2016 Environmental Impact Statement that “no stygofauna were collected during the sampling regime by Eco Logical” and therefore “there is an uncertainty regarding the presence of stygofauna at the project areas, especially Leewood”. The aim of this report is to provide certainty by demonstrating via a more extensive survey of bores across the Pilliga that stygofauna do indeed exist in the shallow aquifers of the Pilliga Forest, are at risk from the current and proposed future development of Coal Seam Gas production and therefore need to be considered and included in the environmental management program.

Introduction

I was briefed by EDO NSW on behalf of the North West Alliance to provide expert advice on the Narrabri Gas Project. The following report outlines my opinions regarding the environmental impact statement (EIS) that has been prepared for Santos’ Narrabri Gas Project, particularly regarding issues related to groundwater and surface water quality. I have prepared this report in accordance with the Expert Witness Code of Conduct.

Stuart Khan Associate Professor, School of Civil & Environmental Engineering. 

According to the EIS, around 37.5 gigalitres of water would be extracted from the target coal seams over the life of the project. Water production is generally not consistent over the life of a CSG well, but much greater volumes are extracted during the first few years, with significant declines thereafter.
The EIS describes the quality and management of produced water in Chapter 7. Somewhat unhelpfully, the salinity of the produced water is described in terms of electrical conductivity (in units of microSiemens per centimetre), rather than an actual salt concentration (in units of mg/L). It is stated that the average salinity is around 14,000 microSiemens per centimetre. The EIS states that “this level of salinity is approximately 30 percent of the salinity of seawater, which is around 50,000 microSiemens per centimetre”. 

1. Introduction

I confirm that in preparing this report I have read the Expert Witness Code of Conduct under the Uniform Civil Procedure Rules 2005 and I agree to be bound by it. The documents I have utilised in preparing this report are listed under the references section at the end of the report.