Tighes Hill Remediation Project Update

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Griselda Perry
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1 3 September 2015 Tighes Hill Remediation Project Update This presentation includes forward-looking statements. Actual future conditions (including economic conditions, energy demand, and energy supply) could differ materially due to changes in technology, the development of new supply sources, political events, demographic changes, and other factors discussed herein (and in Item 1A of ExxonMobil s latest report on Form 10-K or information set forth under "factors affecting future results" on the "investors" page of our website at This material is not to be reproduced without the permission of Exxon Mobil Corporation.

2 Agenda Introduction Site History Investigation Works and Remediation Planning Remediation Project Status Community Communications Questions?

3 Tighes Hill former Terminal & Depot 3.7 ha site located at 110 Elizabeth Street, Tighes Hill

Site History 1936 - Atlantic Union Oil Co petroleum bulk handling Terminal, Depot vacant 1962 Atlantic changed name to Esso Standard Oil (Australia) Pty Ltd, wharf pipeline constructed 1980s Depot

4 Site History Atlantic Union Oil Co petroleum bulk handling Terminal, Depot vacant 1962 Atlantic changed name to Esso Standard Oil (Australia) Pty Ltd, wharf pipeline constructed 1980s Depot started as Esso trucking terminal 1991 Site purchased by Mobil - Terminal operations ceased. Depot continued as Mobil distributor trucking terminal Depot operations ceased Demolition all tanks removed 2008 Demolition final removal of office and gatehouse

5 Terminal & Depot (looking SE)

6 Entrance to Terminal Office and Gatehouse prior to demolition

7 Investigation Works Desktop Phase 1 ESA Boreholes/Wells Off-site ESA incl vapour sampling In Kings Rd To assess: background history Groundwater Monitoring To investigate: geology hydrogeology site impacts Test Pits To understand seasonal changes trends 7

across Terminal Used to verify/delineate extent of LNAPL

8 Investigation Works (cont d) Laser Induced Fluorescence (LIF LIF=capability to see LNAPL with depth 41 locations across Terminal Used to verify/delineate extent of LNAPL Helps better target remediation efforts Some molecules emit light 8

6m (central part) LNAPL occurrence from both LIF and soil bores has good

9 Investigation Works (cont d) LIF Results LNAPL extends through eastern central part of the Terminal, to max depth of 2.6m (central part) LNAPL occurrence from both LIF and soil bores has good correlation LNAPL largely residualised, not mobile Detailed investigation = better understanding 9

(north west) and terminal (central east) Adsorbed and dissolved HC impacts mirror the LNAPL.

10 Conceptual Site Model (CSM) Geology and Hydrogeology Fill (up to 1.5 m thick) underlain by natural sand/clay Shallow groundwater within fill and natural material Impacts LNAPL isolated well locations at depot (north west) and terminal (central east) Adsorbed and dissolved HC impacts mirror the LNAPL. Impacts confined to site and considered stable CSM = picture of environmental data gathered Receptors incl qualitative risk assessment On-site commercial site users and maintenance workers Off-site commercial users and maintenance workrs Off-site residents Environment of Throsby Creek 10

11 Remedial Pilot Trials Pump & treat MPVE Try before you buy Ex-situ Bioremediation 11

Quantitative Risk Assessment (QRA) & Ecological Risk Assessment (ERA) Site-specific, assessment of potential risk from site impacts Identify hazard (site contamination), identify

risk characterization and risk based trigger levels (RBTL) Potential for unacceptable risk to commercial site users from LNAPL impact RBTL developed for soil and groundwater to inform

12 Quantitative Risk Assessment (QRA) & Ecological Risk Assessment (ERA) Site-specific, assessment of potential risk from site impacts Identify hazard (site contamination), identify potential receptors (humans, environment), assess ways for exposure to hazard, evaluate risk from exposure 4 step process - CSM review/update - exposure assessment - toxicity assessment - risk characterization and risk based trigger levels (RBTL) Potential for unacceptable risk to commercial site users from LNAPL impact RBTL developed for soil and groundwater to inform future remedial works Fate and transport (F&T) modelling showed unlikely negative impact to Throsby Creek from site impact migration QRA incl F&T to be updated post remedial monitoring (if required) 12

Remedial trials identified excavation, exsitu bioremediation and re-use as preferred remedial option 12 areas (across

13 Remediation Action Plan (RAP) LNAPL impact identified at depot and terminal Potential for unacceptable risk exists to commercial site users and intrusive workers on site from LNAPL Remediation required to remove this unacceptable risk Remedial trials identified excavation, exsitu bioremediation and re-use as preferred remedial option 12 areas (across depot and terminal) identified for remediation Remediation scope and timing in accordance with VMP Ready to commence Site Remediation 13

14 Remediation Works Status Stage 1 - Principal Works 7,000m 3 impacted soil excavated & treated 3,000m 3 treated soil backfilled in excavations Environmental controls: Groundwater Sediment Dust Odour Vapour Air Monitoring Stage 2 - Principal Works 6,000m 3 impacted soil excavated & treated 10,000m 3 treated soil backfilled in excavations Enhanced environmental controls: Odour Vapour 14

Potential for Asbestos in Soils Historical filling = potential for buried asbestos Found at low concentrations in depot (uncontrolled fill) Found at very low concentrations and limited extent in

15 Potential for Asbestos in Soils Historical filling = potential for buried asbestos Found at low concentrations in depot (uncontrolled fill) Found at very low concentrations and limited extent in terminal Higher standard of care adopted = all soils managed as potential asbestos WorkCover NSW notified & removal permit obtained Licensed asbestos removal contractor engaged Asbestos Removal Control Plan (ARCP) prepared to document safe work practices for handling asbestos during remediation and disposal ARCP protects health of workers and members of the public 15

16 Enabling Works Making a Start Removal & disposal of redundant infrastructure Concrete breaking & crushing for backfilling or disposal Environmental controls = negligible dust or pipe spills 16

17 Excavation & Treatment of Impacted Soil Excavation of impacted soils Transfer to stockpile for treatment Environmental controls = negligible dust Soil mixing with nutrients Completed excavation & soil validation sampling 17

18 Backfilling & Reinstatement Negligible Dust = Environmental Controls Backfilling with treated soils Controlled compaction Finished surface 18

19 Environmental Controls: Water Management (Groundwater Protection) Protection of Throsby Creek & local users Product separation & recovery by absorbent booms Product capture & recovery absorbent peat 19

Protection of internal storm drains Boundary

20 Environmental Controls: Sediment Management Protection of Throsby Creek & Recreational Users Protection of internal storm drains Boundary protection of storm drains - hay bales and silt fencing 20

suppressant application to stockpiles (controls

21 Environmental Controls: Dust and Odour Management Dust suppression by water spraying of truck loads Odour suppressant application to stockpiles (controls airborne dust too!) Protection of site workers & local community 21

22 Environmental Controls: Dust and Odour Management Stockpile covering to prevent or minimise dust & odour generation Protection of site workers & local community 22

23 Environmental Controls: Dust and Odour Management Prevent / minimise odour emissions Dedicated Fogger Units Odour suppressant spray mist Excavation areas and boundary locations 23

24 Environmental Controls - Air Quality Monitoring Volatile Organic Compounds (VOC s) and odours constantly monitored Asbestos and VOCs at site boundary are monitored throughout the working day Subjective odour surveys beyond site boundary in local community 24

offensive odour Apply direct to excavations on digging Prove to EPA & local community it works!

25 Stage 2 Remediation Works What Can We Do Better to Prevent Odour? Odour control ring main along sensitive boundaries + Met Station Enhanced misting effect to prevent offensive odour Apply direct to excavations on digging Prove to EPA & local community it works! Performance Test Use in-situ encapsulating agents to capture vapour Apply direct to excavations on digging Apply to stockpiles during treatment 25

Community Communications Community meetings share

progress, discuss concerns Neighbourhood letters

community Fact sheet information on specific issues of

abreast of remediation progress and provide avenue for

26 Community Communications Community meetings share information on remediation activities and remediation progress, discuss concerns Neighbourhood letters distribute project-related information to a wider community Fact sheet information on specific issues of interest Tighes Hill webpage (in Sep) - keep community abreast of remediation progress and provide avenue for questions or enquiries

27 Questions?

Multiphase Extraction (MPE):

Multiphase Extraction (MPE): Remediation Trials in New Zealand 2010 Richard Howard Senior Environmental Scientist URS New Zealand Ltd CHRISTCHURCH 2 Contents Background to Multiphase Extraction (MPE) Introduce