Meeting #5 Group Closure Working Berrima Colliery€¦ · Meeting #5 >Welcome New Berrima Hall 18 November 2019. Titlefefefefeﬀﬀ4g45g4545 Agenda 1. Welcome and Apologies 2. Terms

Berrima Colliery - Closure Working Group

Meeting #5New Berrima Hall 18 November 2019>Welcome

Titlefefefefeffff4g45g4545

Agenda

1. Welcome and Apologies2. Terms of Reference - Conduct of CWG Members3. Review of minutes & actions4. Water Quality/Ecology Update - Greg Johnson5. EPA Toxicity Assessment - EPA6. Bulkhead Seals Update - Greg Johnson7. EPL/CCL Updates - Greg Johnson8. Mandemar Lane Update - Greg Johnson & Fabio Colluso9. Communication Update - Tom Horn (BCW)

10. General business11. Next meeting


1. Welcome - CWG Representatives, Apologies & Guests

● Boral - Fabio Colusso, Greg Johnson, David Spears (apology), Tom Horn (BCW)

● Resource Regulator - Greg Kininmonth, Peter McMillan

● Environment Protection Authority - William Dove, Andrew Couldridge

● WaterNSW - Ravi Sundaram

● Wingecarribee Shire Council - Barry Arthur

● Western Sydney University - Dr Ian Wright,

● Community - Clive West, Alan Lindsay, Graham Kelly, Ray Nolan, Julian Brophy, Tony McCormick

● Independent chair - Brad Mullard

● Minute taker – Rob Byrnes


2. Terms of Reference - Code of Conduct of CWG Members


3. Review of Minutes – suggested amendments


4. Surface Water Monitoring Update


Surface Water Monitoring Update - October 2019

We continue to use the drone to sample difficult locations

● Monthly sampling of water quality continuing● Spring 2019 Macroinvertebrate sampling

undertaken in September● EPA participation in September sampling which

included their own toxicology assessment


Surface Water Monitoring Update Summary of Findings

● Since the installation of the bulkheads, the discharge continues to be significantly down from 2.5ML to 0.125ML per day

● Concentrations of metals and other parameters downstream have progressively reduced and are consistent with upstream water quality.

● Anticipating the the groundwater will be fully recharged behind the bulkheads installed in the coming months and that we will reinstate the passive treatment shortly to manage this.

● Current Adit discharge water quality○ pH remaining neutral around 7○ EC around 800 uS/cm○ Dissolved Fe - 0.5 mg/L○ Dissolved Mn - <2mg/L○ Dissolved Ni - approx 0.75 mg/L○ Dissolved Zn - <0.25 mg/L


Wingecarribee River Monitoring ● pH - upstream and downstream neutral. pH drop

July to September

● Conductivity - minor influence on EC, stream flow also low

● Nitrates - While stream flow is low, influence of Bowral STP more pronounced.


Surface Water Monitoring Update

● Iron - Drops rapidly, generally follows upstream sites. Rivulet shows occurrence of naturally high fluctuations

● Mg - Decreases rapidly through mixing zone. During 2019 there has been a decline close to discharge and increase downstream


Surface Water Monitoring Update ● Nickel - Average Ni Conc. since Jan 2018 is

0.009mg/L which is below AZECC default value of 0.011mg/L. Conc. at rivulet 0.002mg/L

● Zinc - Since April 2019 conc. Have increase above and below discharge. Similar changes at rivulet. Changes not from discharge. Zn conc. In river more a function of rainfall and river flow.


Macroinvertebrate study update - May 2019 Sampling Summary● General observations was that there appeared to be less

iron floc/precipitate downstream of the adit. We believe this decrease has led to an increase in abundance , family richness and EPT. While we have not done a statistical analysis yet it appears as though this is not solely related to seasonal change as other sites (Medway and upstream of the adit) did not show the same marked changes as observed at Site 3.

● Most sites either had decreased or had relatively the same number of different taxa. The exception of this is Site 3 - the first site downstream which has almost doubled.


Macroinvertebrate study update - May 2019 Sampling SummarySite 3 Detail

● Increase in abundance

● Macroinvertebrate taxonomic richness (type of bugs) increased

● Increase in sensitive invertebrates i.e. EPT index. EPT was higher than upstream site in May 2019

Note: Dr Ian Wright reported EPT downstream mean of 0.7 in 2017


Macroinvertebrate study update - September 2019 preliminary findings● Appears to be an improvement in stream health during 2019● Indicated by increases in EPT, abundance and taxonomic richness similar to upstream and tributory

reference● Improved stream health with all sites, particularly sites 300m and 1000m down stream moving towards

reference sites● Thought to be driven by increase in pollution sensitive Riffle Beetle● Passive treatment and reduce discharge main drivers

○ Reduction in dissolved metals, salinity and reduced Iron floc.● Iron floc thought to be affecting aquatic habitat and food webs which limit abundance and richness of

sensitive invertebrate.● This reduction has led to more sensitive species being able to colonise the flowing water/rifle habitat

immediately downstream of the mine discharge.


5. NSW EPA - Ecotoxicity Report

● September 2019 - EPA and members of the Environment, Energy and Science Group in the DPIE participated in the monthly sampling round taking independent samples

● Purpose was to take samples upstream and downstream of the adit and compare with previous testing by the EPA.

● Report found water collected upstream and 150m downstream of the adit were not chronically toxic to standard laboratory test organisms or acutely toxic.

● A comparison of the chemical analyses revealed that the conductivity, alkalinity, dissolved organic carbon and concentrations of nutrients, anions and metals were consistent between upstream and downstream samples

● In comparing downstream samples from December 2017 and April 2018, conc. Of trace metal and major ions had decreased.

● In the current sampling event no metals exceeded the Australian and NZ Guidelines for Fresh and Marine Water Quality for the 95% level of protection.

The report will be available on the Boral Berrima website.


6. Bulkhead Sealing Plan Update - Location in respect of workings


Bulkhead Seal installation update





● Internal mine water treatment pumps stopped on 24 April 2019● Bulkheads installed by end May 2019● Personnel inspecting and recording observations twice a week● Average rise of 20mm/day or 140mm/week inbye of bulkheads - linear fashion● Observations to date - minor seepage in ribs adjacent to the bulkheads and some through floor ● Bulkheads down dip in roadways, other water from western area of mine also provides some water at

front. This is managed by small air pumps.● Water quality behind bulkheads similar to 2017 drainage scenario i.e elevated minerals● Passive treatment system recommissioned and ready to activate when mine waters rise to near the

height of the overflow point.● Hydrology (ground water) model indicated a 2.3m rise before groundwater would transition (leak)

through the strata/underground workings. This has not occurred and water continues to rise.● As at 14 November 2019 there is approximately 1100mm before overflow, at the current rate it will

bypass the bulkheads around 14 January 2020● If the mine saturation increases it is possible that alternative pathways may occur


7. Environmental Protection Licence/ CCL 748 Updates

EPL 608

No modifications. PIRMP drill undertaken in October. PIRMP updated. Annual return due for submission 30 December 2019

CCL 748

MOP - Berrima colliery Mining Operations Plan dated September 2019 - Notice of Approval received October 2019


8. Mandemar Lane Update

● Last meeting the Mandemar Lane resident representative Tony McCormick presented to the CWG.

● Tony raised concerns regarding○ Subsidence and vibration impacts on structures, services and surfaces○ Bores drying and/or collapsing○ Conductivity increases and soil salinity○ Excess water issues○ Surface water flow changes in Woolshed Creek○ Increased surface water○ Land deformations○ Iron staining from bore waters

● Boral appreciates the concerns of the Mandemar Lane residents and are committed to investigating their concerns

● The focus of the CWG to date has been the mine discharge water quality, ● The following is some background information on the mining area for the CWG members


Mandemar Lane Locality Map


B62 Cross Section and water tables

● There are 3 water tables

● Upper Hawkesbury Sandstone

● Lower Hawkesbury Sandstone

● Illawarra coal measures

● At B62 the coal seam is below the river


B62 & B63 Water levels within each water table


Geology and groundwater

● Robertson Basalt - Localised perched aquifers● Dolerite dykes - There are a number of igneous dykes which run through the mining area● Hawkesbury Sandstone - Divided into two layers by a siltstone/claystone interlayer

○ Upper Hawkesbury Sandstone (Aquifer) - static water level 50-90 mbgl○ Lower Hawkesbury Sandstone (Aquifer) - static water level 120-140 mbgl

● Wongawilli Coal Seam - Aquifer static water level 170-180 mbgl

● Recharge to the system is mainly through rainfall infiltration, with a smaller component attributed to regional (lateral) inflows although B63 is mainly sourced lateral flow.

● Any inter-aquifer leakage (due to vertical fracturing) would be from shallow to deeper bearing zones● Based on water quality data, aquifer contributions to the mine waters include (70% Lower HS, 20%

from the coal seam and 10% from the Upper HS.● Hydrochemical Features

○ Mine discharge waters - fresh (EC 600 - 800uSm), neutral pH mean 7.3○ Upper Hawkesbury Sandstone - Mildy brackish (EC 1000 - 1600 uS/cm), neutral pH mean 6.9,

iron enriched 13.6, groundwater <50 years old○ Lower Hawkesbury Sandstone - fresh (EC 730 uS/cm), neutral pH mean 6.8, iron enriched 5.5○ Illawarra Coal Measures - fresh (EC 460uS/cm), neutral pH 7.6, low iron 0.5


Bord and Pillar Mining - Technique and Subsidence

● Berrima Colliery is a Bord and Pillar mine, not a longwall mine● Subsidence impacts from Bord and Pillar mining is less extensive than longwall mining● Bord and pillar involves parallel tunnels being driven into the coal seam from the mine entrance.● These form a series of self-supporting roadways, called ‘bords’ or ‘rooms’, leaving behind a grid

of pillars (blocks of coal between roadways)● The pillars are designed to provide stability to the void (bord) in the long term and support the

roof strata above the seam.● The extent to which the coal is removed depends on the mine subsidence permitted above the

extracted area. If no subsidence is permitted then all pillars left in place, if a small amount is permitted then alternate rows of pillars can be removed. Eg subsidence protection zones.

● As the depth of cover increases, the width of pillar increases to carry weight of overburden● Subsidence of the ground surface above bord and pillar first workings results from the compression

of the coal pillars and the strata above and below the seam from the overburden weight.● Where pillars are designed to be stable, the vertical subsidence is typically less than 20mm● Vertical subsidence <20mm can be considered to be no more than seasonal variations that occur

from natural processes● Secondary works can increase the level of subsidence● The most recent mining at Berrima Colliery included subsidence protection zones beneath

houses.● Mining was ceased in 2013 and an end of panel report was submitted in September 2014● Subsidence Advisory NSW administers compensation to landowners for structures etc. and has

accepted claims for damage from Berrima Colliery● For other compensation Part 13 of the Mining Act 1992 contains wide ranging compensation

provisions to ensure landholders are not financially disadvantaged by mining


Land Access Agreements

● Prior to undertaking sampling and investigations we require access agreements with landowners

● Our priority is to access property where we have previously monitored as per the Subsidence Management Plan and associated Environmental Management Plan

● By gathering this data we can assess localised changes to the water tables and water quality from historical records prior to mining within the area

● We can also understand concerns of those landholders impacted by mining within the most recent workings of the mine.

● Previous access undertaken when the mine was in operation and no records of access agreements can be found by Boral or tabled by the landowners to date, while Boral did own the lease, Boral were not the operators of the mine

● When the mining ceased in 2013, monitoring reduced with the last monitoring undertaken in 2016.● Boral has been working with landowners for the last 12 months to gain access, and are confident

we can agree on terms soon.● Boral is actively working towards resolving access concerns to undertake monitoring and investigate

concerns in the priority areas and have committed to meeting with Mandemar Lane residents to address


9. Communications Update - Tom Horn (BCW)


•Activity undertaken:Dedicated Community Website:•Microsite was launched in September•Single home for all information on the Berrima Colliery closure•Designed specifically for the community and easy to navigate.•Provides all reports, minutes etc. from former site, also gives overview of plans underway and steps involved•Includes detailed Q&A section•Houses all updates shared with media and the community•Infographics outlining the passive treatment process and also the bulkhead installation and operation•Includes four minute video on the colliery and the work being undertaken as part of the closure project•Provides easy contact form for the community and area to sign up to receive digital newsletters and updates

9. Communications Update - Tom Horn (BCW)


•Activity undertaken:Dedicated Community Website:•Over 300 unique visitors•Average of 3 minutes on the website•Promoted through media, newsletters and engagement day•10 people have signed up for updates

Further additions planned:-CWG member contact option-Updated Q&A-Ongoing updates to reports and resources


•Activity undertaken:Informational Video:•Four minute video dedicated to the Berrima Colliery closure•Provides background of site operation and overview of activity being undertaken•Has received 31 views to date

Infographics:•Two infographics developed and set live•One focused on bulkheads•One focused on passive water treatment


Communications continued

Activity undertaken:Community Engagement Days•Four days held on 31 Oct, 1Nov, 8 Nov, 9 Nov•25 attendees•Approximately an hour per attendee•Provided maps, images and plans of Colliery site•Provided graphic representations and video•Created in-depth conversations and an opportunity for people to better understand work and plans as well as raise concern•Next sessions planned for early 2020 (post holiday period)•Promoted through:Online and radio advertisingCommunity postersBerrima Colliery micrositeCWG members Newsletter


10. General business


10. Next meeting date

Proposing - Monday 9 March 2020

Location – Berrima Anglican Church Hall

Documents

Meeting #5 Group Closure Working Berrima Colliery€¦ · Meeting #5 >Welcome New Berrima Hall 18 November 2019. Titlefefefefeﬀﬀ4g45g4545 Agenda 1. Welcome and Apologies 2. Terms