Groundwater Management Bird in Hand Gold Project TERRAMIN AUSTRALIA - - PowerPoint PPT Presentation

TERRAMIN AUSTRALIA LIMITED

SLIDE No. 1

Groundwater Management

Bird in Hand Gold Project

LEGISLATIVE PROCESS

➤ Mine is approved under Mining Act and

any other permit it requires (EPA, DEWNR, SafeWork)

➤ Mine is subject to Natural Resources

Management Act

➤ Department advised that Project must

comply with objectives of Water Allocation Plan

➤S. 128 - Authorised Use of

Water

➤ Used by projects – ag, civil, mining ➤ Terramin proposing to have a neutral

groundwater balance

➤ MAR testwork program in 2018 – to be

agreed with DPC and DEWNR

HOW IS INFORMATION COLLECTED

➤ Taking water levels and field

measurements (pH, TDS, etc)

➤ Sending water samples to the

laboratory

➤ Drilling monitoring bores

(piezometers)

➤ Equipping bores with pressure

transducers, or dipping manually

➤ Live monitoring for quality and

level can be set with trigger levels/alarms

➤ Same style system proposed for

monitoring construction and

• perations

GROUNDWATER BASELINE

➤ Groundwater census

2014-2017

➤ Water levels ➤ Water quality ➤ Springs and

groundwater dependent ecosystems

➤ Investigation bores

drilled and pump tested in 2014

➤ Understanding of system

• n a local and regional

scale

➤ Groundwater model

constructed based on

• ver 250 assays,

thousands of levels, 60 drill holes, and aquifer properties

Transient Calibration – Seasonal groundwater decline (m) due to irrigation pumping

400 405 410 415 420 2/03/14 18/09/14 6/04/15 23/10/15 10/05/16 26/11/16 RSWL

6628-8937

Woodside

365 370 375 380 385 2/03/14 18/09/14 6/04/15 23/10/15 10/05/16 26/11/16 RSWL

6628-10199

BIHGP

360 370 380

RSWL

6628-18637

390 395 400 405 410

RSWL

6628-8945

MODELLING AND CALIBRATIONS

GEOLOGY - AQUIFERS, FRACTURES AND SALINITY

PROBE DRILLING

• 4. Water moves around

the grouted shell following natural flow paths 4.

MANAGED AQUIFER RECHARGE

INVERBRACKIE CREEK – BASED ON CDM SMITH CONCEPTUAL IMAGE

INVERBRACKIE CREEK – BASED ON CDM SMITH CONCEPTUAL IMAGE

Reinjection Bores Depressurisation bore

REINJECTION CONCEPTS

Water level Not to scale

~10-15 metres

REINJECTION CONCEPTS

< Mine Irrigation bores >

Not to scale

GROUNDWATER MONITORING NETWORK CONCEPTUAL

➤ Additional monitoring

wells to be placed between receptors and reinjection:

➤ Private wells ➤ Inverbrackie Creek ➤ Dawesley Creek

catchment

➤ High frequency

monitoring of :

➤ Groundwater seepage

& quality

➤ Groundwater levels &

quality

• --- Reinjection bore network
• --- Monitoring bore network

REINJECTION SYSTEM

➤ Dept. Environment Water and Natural

Resources Well Drainage Permits

➤ All with license conditions ➤ Cannot impact water quality of existing

bores

➤ Cannot take away existing users

access to water

➤ Pipelines along existing fence lines and

existing cleared land

LIVE MONITORING

➤ Live and public – web hosted ➤ Monitoring bores between

reinjection bores and irrigation bores

➤ Monitoring will compare

against mine water flows and levels -

➤ Irrigation bores ➤ Native vegetation area ➤ Inverbrackie Creek ➤ Monitoring includes salinity

SIMILAR PROJECTS

➤ Ernest Henry, QLD - Grouting ➤ Ophthalmia Dam, WA - MAR

To maintain the hydrological regimes of groundwater and surface water so that existing and potential uses, including ecosystem maintenance, are protected. Works within Pilbara Groundwater Allocation Plan

➤ Broken Hill MAR investigation ➤ Used to supplement town’s water supply during drought

Parameters Ernest Henry Bird in Hand Inflows (l/s) 75-100 1-38L/s Pressure (kPa) 3500 1400 Temperature (oC) 49 20

TERRAMIN AUSTRALIA LIMITED

SLIDE No. 19

Proposed Outcomes and Measurement Criteria

No adverse impact to the supply or quality of water by the mining operations to existing users and water dependant ecosystems

TERRAMIN AUSTRALIA LIMITED

SLIDE No. 20

No adverse impact to the supply or quality of water by the mining operations to existing users and water dependant ecosystems

Measurement Criteria – How should we demonstrate this?

Suggestions ► Monitor water levels and quality in new monitoring wells (“piezometers”) – live and publically available

• Located between reinjection wells and existing users

► Monitor water levels and quality in existing private bores (agreed frequency at PEPR) ► Monitor pressure of injection system at new monitoring wells

• Located between reinjection wells and existing users

► Monitor and report water volumes extracted and reinjected - public ► Comply and report against section 128 license conditions - public ► Comply and report against DEWNR drainage permits - public ► Annual audit and report against DEWNR s. 128 and drainage permits - public

TERRAMIN AUSTRALIA LIMITED

SLIDE No. 21

Discussion -

 Comments on Outcome Criteria?  Any questions from the Groundwater Assessment?  Any questions on IGS Peer Review or CDM Smith Peer Review?

SURFACE WATER MANAGEMENT

Bird in Hand Gold Project

BASELINE ENVIRONMENT

➤ Desktop Study – looked at

DEWNR and EPA reports

➤ Samples obtained over 3

years from Inverbrackie Creek, tributaries and dams (>370 samples)

➤ Before-After, Control-

Impact (BACI) approach – from ANZECC (Aus/NZ Environment Conservation Council)

➤ Springs identified from

water samples – chloride mass balance

Samples taken using the BACI (Before After / Control Impact) method Macroinvertebrate + habitat work – Habitat assessment using AusRivas – Australian River Assessment System

OUTCOME OF BASELINE STUDIES

➤

EPA studies:

➤

2008 – 2016 rated between very poor and poor

➤

Water turbid, enriched with nutrients.

➤

Weedy shrubs over introduced grasses

➤

AC Environmental Studies

➤

Waterway highly disturbed

➤

Metals: higher than freshwater trigger levels at some sites: Arsenic, cadmium, copper, lead and zinc

➤

High levels of ammonia and nitrates further downstream

➤

Higher salinity after rainfall

➤

Macroinvertebrate: Low diversity

➤

Nutrients are increasing algal growth and biological

• xygen demand

➤

OPPORTUNITY: With appropriate mitigation and management practises the health of the stream could be restored and maintained.

SITE CATCHMENT MAP

SURFACE WATER MANAGEMENT STRATEGY

Proposed Outcome: No contamination of natural water drainage systems, streams and rivers, groundwater, land and soils occurs either on or off site

➤ Maintain existing flow into creek systems ➤ Measurement Criteria: ➤ Water quality – any water flowing offsite must be

better than upstream or EPA Water Quality Guidelines

➤ Apply individual source treatments to manage

pollutants – where required

➤ Water Sensitive Urban Design strategies ➤ 30 000 sedges planted this year ➤ System will provide a benefit and require no

maintenance post mine closure