Appendix A Effects, stressors and impact causes for the Gloucester subregion

SW quality

117

GW quality

50

SW volume

25

GW quantity

14

Change in GW pressure

10

SW directional characteristics

10

GW composition

7

SW flow

6

Aquifer properties

2

GW flow (reduction)

1

Soil quality

1

TSS

68

Pollutants (e.g. metals, trace elements, sulfides or phosphorous)

39

TDS

34

Hydrocarbons

32

SW flow

30

Drilling mud products

13

GW flow

12

Change in GW pressure

11

GW composition

8

pH

6

Chemicals

4

Hydraulic fracturing chemicals

4

Organic pollutants

4

Aquifer properties

2

Change in GW pressure increase

1

Soil quality

1

Subsidence

1

SW composition

1

Human error, accident (e.g. containment loss, digging, ignition, logging machine fault, formation variation)

33

Litter, spills

24

Containment failure/leaching/flooding (e.g. lining material failure, loss of holding capacity, pipe failure, dam failure)

21

Corridor/site vegetation removal

19

Diverting site/corridor drain line

17

Inevitable, Deliberate

13

Natural disaster (e.g. bushfire, flooding, earthquake)

8

Poor design, construction, implementation, management (e.g. abandonment practice, bore location, lack of knowledge, historical data records, sealing practices, geological characterisation)

8

Number of drilling control issues

5

Inappropriate disposal

4

Ignition following pipe failure

3

Incomplete grouting

3

Incidental to vegetation removal and compaction in pipeline corridor

2

Aquifer connected to coal seam

1

Aquitard leaks

1

Chemical interactions in soil

1

Depressurisation

1

Evaporation concentrates salt on surface

1

Fault closing

1

Fault open or opening

1

Incomplete reservoir knowledge, too much pressure

1

Increase baseflow

1

Interrupting ephemeral watercourses

1

Production of water

1

Salt mobilisation due to irrigation

1

SW quality

95

GW quality

43

SW directional characteristics

23

SW volume/quantity

18

GW quantity/volume

10

SW flow

9

GW composition

6

GW directional characteristics

4

Change in GW pressure

2

GW flow

2

GW recharge

1

TSS

72

Pollutants (e.g. metals/trace elements/sulfides/phosphorous)

42

SW flow

28

TDS

20

Hydrocarbons

19

pH

14

GW flow

8

Drilling mud products

6

GW composition

6

change in GW pressure

2

GW quantity/volume

2

Subsidence

1

SW composition

1

SW volume/quantity

1

Human error, accident

19

Diverting site drain line

17

Corridor, site vegetation removal (e.g. removing rocks and topsoil)

14

Litter, spills

14

Containment failure, leaching, flooding (e.g. lining material failure, plant failure, mechanical failure, pipe fatigue)

12

Inevitable, Deliberate (e.g. mining below watertable, in recharge areas, removal of rock

mass, more than one aquifer intersected by pit)

11

Coal characteristics, waste characteristics, spontaneous combustion, bushfire

8

Poor design, construction, implementation, management (e.g. Abandonment practice, bore location, lack of knowledge, historical data records, sealing practices, geological characterisation)

8

Incomplete grouting

4

Ineffective revegetation due to (e.g. disease, poor topsoil, fire, weather, weeds)

4

Natural disaster (e.g. earthquake)

3

New topography, combined with timing of new vegetation and rainfall

3

Number of drilling control issues

3

Consolidation of loose backfill

1

Interrupting ephemeral watercourses

1