BURNIE WASTE MANAGEMENT CENTRE STAGE 1 LANDFILL LEACHATE TREATMENT WETLAND DEVELOPMENT PROPOSAL & ENVIRONMENTAL MANAGEMENT PLAN NOVEMBER 2015 Perth 12 Monger Street PerthWA,Australia 6000 t +61[0]8 9227 9355 f +61[0]9 9227 5033 ABN : 39 092 638 410 Melbourne 2/26-36 High Street Northcote VIC, Australia 3070 t +61[0]3 9481 6288 f +61[0]3 9481 6299 www.syrinx.net.au
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BURNIE WASTE MANAGEMENT CENTRE
STAGE 1 LANDFILL LEACHATE TREATMENT WETLAND
DEVELOPMENT PROPOSAL &
ENVIRONMENTAL MANAGEMENT PLAN
NOVEMBER 2015
Perth
12 Monger Street
PerthWA,Australia 6000
t +61[0]8 9227 9355
f +61[0]9 9227 5033
ABN : 39 092 638 410
Melbourne
2/26-36 High Street
Northcote VIC,Australia 3070
t +61[0]3 9481 6288
f +61[0]3 9481 6299
www.syrinx.net.au
BURNIE LEACHATE TREATMENT WETLAND
DPEMP
This Development Proposal and Environmental Management Plan was prepared by:
Temperature (Celsius) 7.3 8.1 10.1 13 16.7 17.6 18.5 31
Ammonia as N mg/l ND 1.61* 0.05 0.03
Nitrate as N mg/l~ 0.427 0.432 0.441 0.47 0.498 0.508 0.512 2 0.7 0.625 0.435
Nitrite as N mg/l ND
Total Nitrogen as N mg/l ~ 0.155 0.17 0.2 0.438 0.681 0.715 0.732 4 0.5 1.8 1.25
Phosphorus, Dissolved
Reactive as P mg/lND
Total Phosphorus as P mg/l ~ 0.011 0.012 0.015 0.021 0.025 0.028 0.029 4 0.05 0.045 0.030
Total Suspended Solids
(1.5µm)mg/lND <5 <5
Total Suspended Solids
(0.45µm) mg/LND
ND= No data, ~ = Insufficient data for generation of WQOs (va lues included for information purposes only)
* ANZECC 2000 guidel ines - Trigger va lues for toxicants . 95% protection level adjusted for pH
Syrinx data (April
2014)
# ANZECC water qual i ty guidel ines (2000) - Default trigger va lues for phys ica l and chemical s tressors for south-east Austra l ia for s l ightly dis turbed ecosystems
total
ammonia
nitrogen
as N^
(mg/L)
Annual 0.051
Summer 0.048~
Autumn 0.070~
Winter 0.055~
Spring 0.043~
CAM CATCHMENT
WQGs
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While the EPA data and the derived protection limits provide an important understanding of
the ecosystem health of the Cooee Creek, using these values as the water quality protection
trigger values for discharging treated leachate (and stormwater) into the creek system, poses
the following concerns, especially in terms of nutrient targets:
None of the nutrient data collected by the EPA included the unnamed tributary of
Cooee Creek, which is the proposed receiving environment for the treated leachate.
This is particularly the case for ammonia for which the data was adopted from the Cam
Catchment data set. As discussed above, the Cooee Creek unnamed tributary is
already a highly disturbed system. This relatively high level of disturbance is evident in
the recent (April 2014) WQ and sediment data for this tributary, compared to the
Cooee Creek itself (see section above) In contrast, Cooee Creek and the Cam
Catchment as larger scale systems, are far less disturbed, and predominantly limited
to agricultural influences. Such a marked difference between the ecosystem conditions
questions the appropriateness of using the Cam Catchment / Cooee Creek data for
setting the discharge levels for the unnamed tributary.
Nutrient protection levels (TN, TP, nitrate) were derived from only 2 to 4 sampling
events, the last one being in 2007. Such a small number of samples is generally not
sufficient to derive a statistically significant local reference system (as acknowledged
by the EPA in this project). The April 2014 sampling events, if included in the overall
data set would inevitably increase the median, and hence the 80th
percentile trigger
values for TN and TP.
The ammonia trigger values set by EPA (for the Cam Catchment) reflect the levels of
ammonia as a chemical stressor, not as a toxicant.
Based on the ANZECC 2000 Guidelines, nutrients (TN and TP) are generally
considered to be non-toxic direct-effect stressors, meaning that they do not have a
toxic effect but rather that elevated levels result in adverse changes to the ecosystem
as a result of nuisance growth of aquatic plants (eutrophication), excessive algal
growth and cyanobacterial blooms. Ammonia and nitrate, on the other hand, are also
toxicants; that is stressors that are directly toxic to biota.
Protection levels for the key stressors such as TN and TP are derived from relevant
reference systems, either from the same or local ecosystems, or from regional
reference ecosystems. The trigger values of toxic stressors such as ammonia and
nitrate are generally determined from laboratory ecotoxicity tests conducted on a range
of sensitive aquatic plant and animal species. These trigger values are outlined in
Table 3.4.1 of the ANZECC Guidelines. In other words, the non-toxic effect of
ammonia is generally ‘managed’ via setting TN protection levels, while its toxicity is
regulated by the set default values outlined in the ANZECC Guidelines.
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Therefore, in terms of appropriate ammonia and nitrate protection levels for discharge to the
unnamed tributary, both ammonia and nitrate should be considered as toxicants and the 95%
protection levels outlined in the ANZECC Guidelines applied (Table 3.4.1 in Guidelines). Given
the pH-dependence of ammonia toxicity, this ammonia protection value should be pH
corrected, resulting in a trigger value of 1.6 mg/L (see Table 23).
Proposed Water Quality Targets for Discharge to Cooee Creek Tributary
As discussed above, the EPA proposed water quality objectives for Cooee Creek were derived
from a relatively small data set which mostly did not include samples from the unnamed
tributary of Cooee Creek and are considered a draft set intended to be progressively updated
as more specific data becomes available. These values are based on the least impacted sites
within the SMD (Slightly to Moderately disturbed ecosystem) and are considered to represent
aspirational Water Quality Targets. If the Creek-specific water quality data gathered as a part
of this project (April 2014) is included in the overall data set this would alter the 20th
/80th
percentile trigger values, especially for nutrients and pH.
Hence, for the purpose of setting up specific creek water quality protection levels that would
adequately reflect both the specific creek data and the objectives set by the EPA, two types of
targets were developed:
1. Interim targets – that fully reflect creek-specific conditions; they were derived using the
monitoring data from April 2014. These targets are intended to be immediately adopted
and implemented.
2. Aspirational targets – derived by inclusion of creek-specific data into the EPA data set.
These targets are intended to replace the interim targets when the EPA dataset is
statistically robust and trigger values set as final, and after the performance of the
treatment system has been validated over several years .
These two target types apply for nutrients and pH only; the targets for other stressors
(physical) adopt the EPA set values, while targets for toxicants and other pollutants were
derived from relevant ANZECC guidelines.
Therefore, the following water quality protection levels are proposed to be used to manage
discharge of the treated leachate into the Cooee Creek unnamed tributary (Table 23):
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Temperature, conductivity, turbidity & Chlorophyll-a – targets as outlined by EPA.
pH and DO
a) Aspirational Targets: Targets determined by including the most recent April
2014 WQ data into the EPA data set and recalculating the 20th
/80th
percentile
trigger value.
b) Interim Target: Target derived as the median values from Cooee Creek and the
unnamed tributary from April 2014 monitoring data (current baseline).
TN & TP
a) Aspirational Targets: Targets determined by including the most recent April
2014 WQ data into the EPA data set and recalculating the 80th
percentile
trigger value.
b) Interim Target: Target derived as the median values from Cooee Creek and the
unnamed tributary from April 2014 monitoring data (current baseline) .
Ammonia – ANZECC 95% trigger values for freshwater ecosystems corrected for pH
(toxicants, Table 3.4.1).
Nitrate and Metals - ANZECC 95% trigger values for freshwater ecosystems
(toxicants).
Fe – EPA advice on soluble iron (target 0.3 mg/L) was adopted together with the
relevant trigger values for total metals as outlined in the ANZECC Primary Industry
Guidelines (2000).
Other chemical pollutants - ANZECC 95% trigger values for freshwater ecosystems.
Faecal coliforms / E. coli – Currently, the creek water is primarily used for irrigation
of pasture and fodder for dairy animals and as a drinking supply for dairy animals. The
use of this water for garden irrigation cannot be excluded although the exact type of
vegetables being irrigated (e.g. salad vegetables or vegetables requiring peeling or
cooking), the extent of any garden areas and frequency of irrigation, as well as the
irrigation methods (via spray or trickle irrigation) is not known.
In terms of potential recreational use, given the current degraded nature of the
unnamed tributary (i.e. erosion, relatively poor water quality, highly impacted by the
extensive urban and agricultural land use in the catchment) this creek is rarely if ever
used for recreational purposes and is most likely used for secondary recreational
activities only, which include activities with less body contact such as fishing.
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In light of this, the following guidelines and trigger values were considered appropriate
for setting the protection levels for coliforms:
o The ANZECC Guidelines for recreational water quality and aesthetics (2000):
the secondary level recreational contact - the median value in fresh and marine
waters not to exceed 1,000 faecal coliform organisms/100 mL or 230
enterococci organisms/100 mL.
o The ANZECC Guidelines for Primary Industry (2000): drinking water for
livestock – the median value not to exceed 100 faecal (thermotolerant)
coliforms per 100 mL (median value).
o The ANZECC Guidelines for Primary Industry (2000): irrigation waters for
pasture and fodder (for grazing animals except pigs and dairy animals) - the
median value not to exceed 100 faecal (thermotolerant) coliforms per 1,000 mL
(median value).
Escherichia coli is a more sensitive indicator of faecal pollution of source water than
thermotolerant coliforms, and are already monitored as part of the routine BCC
leachate monitoring program. Consequently, E.coli and enterococci have been
adopted as the key indicators of microbiological contamination of creek water with
human (and to a lesser degree, animal) faeces. In line with the ANZECC guidelines
outlined above, the protection levels were set to be <230 organisms/100 mL for
enterococci and <100 cfu/100 ml for E.coli.
Note, this protection level is above the trigger values set for irrigation of vegetable
crops that are directly eaten (e.g. lettuce) which is <10 cfu/100 ml. Given the
uncertainties regarding the use of creek water for this particular purpose, and more
importantly, considering the multiple inputs to the creek from nearby residential
properties and farms which include pathogen contaminated agricultural surface run off,
it is questionable if such a pristine water quality (in terms of pathogen) can be
achieved at all.
Surface run-off from agricultural land or irrigated pasture runoff is known to contain a
major numbers of faecal organisms with levels being as high as 40,000 cfu /100 ml
(Carey et al, 2004). Furthermore, the levels of E.coli in Shorewell Creek passing
through the residential areas of Burnie were detected to be ~2,000 cfu/100 ml
(Sharman, R (2002). Consequently, setting up a very stringent pathogen protection
level of <10 cfu/100 mL was considered impracticable and not critical for the protection
of public and animal health, and a more appropriate, less stringent value of <100
cfu/100 ml was hence adopted.
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Table 23. Proposed water quality protection levels for discharge to the Cooee Creek
unnamed tributary
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5.2.9 Biodiversity & Conservation Significance
There are no national parks, nature reserves or wetlands of national significance (RAMSAR) in
the vicinity of the project site (10 km). The site also does not contain outstanding natural
features.
This proposal was referred to the EPBC in November 2014, and was determined as not a
controlled action (APPENDIX 3).
Listed threatened species and ecological communities
Two natural values assessments of the landfill site for BCC have been undertaken in recent
years – one as part of the Stage 2 landfill rehabilitation planning (NEST 2013) and most
recently one as part of the Landfill Stage 1 leachate management project ( APPENDIX 2).
These studies found that there are several species listed under the Environment Protection
and Biodiversity Conservation Act 1999 (EPBC Act) recorded within 500m of the Burnie Waste
Management Centre and along the un-named tributary flowing from the Centre. Several
species are also listed under the Tasmanian Threatened Species Protection Act 1995.
The threatened species listed under the EPBC Act and recorded within 500 m and 1 km of the
un-named tributary or are likely to occur here, based on habitat, are listed in Table 24. The
section of the creek that flows through the BWMC and the unnamed creek itself were found to
be a suitable habitat for the Burnie burrowing crayfish. This was the only species confirmed
within 1 km of the project site. The Green and gold frog and Eastern barred bandicoot could
potentially inhabit this zone (APPENDIX 2), however the survey did not identify individuals or
evidence of their activity. The only evidence of activity for these two species was found in the
creek section 4 kms downstream of the project site. No impacts to the Eastern barred
bandicoot are likely given the key threats to this species are feral animals and remnant
vegetation disturbance.
The nearest State listed Threatened ecological community is an undefined wetland, which is
listed as vulnerable under State legislation (Nature Conservation Act 2002), and occurs ~2
kms downstream of the project site (LIST Database). It is not listed as being of National
significance.
This community was not identified within the NEST (2014) report, however it was noted that
this area is highly impacted from weeds and cattle impacts. Eucalyptus viminalis wet forest,
which is listed as endangered occurs in uplands around the forested Cam River catchment,
however is not within the area of impact.
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Table 24. Threatened species recorded (in bold) within 500m of stream reach and
those potentially present, by habitat type or survey evidence (NEST 2014)
Listed migratory species
Field surveys conducted in July 2014 (NEST 2014) observed only one migratory species with
the potential to inhabit the area is, Lathamus discolour (Swift Parrot) which is an endangered
species.
Vegetation & Flora
Native vegetation of the areas surrounding the project site is reflective of the diverse
topography of the region, as well as localised hydrological and geological influences. Much of
the privately-owned land in the region has been cleared for agriculture, which has impacted on
the water quality of the creeks and groundwater.
The natural vegetation of the region is Eucalyptus obliqua wet forest with broad leaf shrubs
growing on the lower slopes, with white gum wet forest (Eucalyptus viminalis wet forest)
occurring on the upper slopes and outside of the project area of influence. The wet obliqua
forest dominates the Cooee Creek environment. This community is dominated by stringybark
eucalypts (Eucalyptus obliqua) with a mixture of broadleaf species such as blackwood (Acacia
melanoxylon), dogwood (Pomaderris apetela), and an understorey including forest daisybush
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(Olearia lirata), stinkwood, (Zieria arborescens), satinwood (Nematolepis squamea) and
treeferns (Dicksonia antarctica) (APPENDIX 2).
A total of 29 plant species were identified during the site survey in 2014 over a distance of
approximately 4 km, including the project site. None of the identified species are threatened
flora, i.e. they are not present on the list of Ihreatened plants within the Burnie Local
Government Area (Department of Primary Industries, Parks, Water and Environment,
Threatened Species Section (DPIPWE), site accessed November 2015).
Seventeen weeds/exotic species were also identified. Of these, four species (gorse,
blackberry, Cortaderia species and Elisha's tears) are on the list of Declared Agricultural and
Environmental Weeds in Tasmania (DPIPWE Tasmania, site accessed November 2015).
These declared weeds were primarily identified in creek sections surrounded by agricultural
land.
The section of the creek that flows through the BWMC was found to be highly impacted, with
heavy weed infestations. The dominant weed species in areas close to the BWMC is the
invasive riparian weed, Glyceria, which is classified as a Non-declared Agricultural and
Environmental Weeds in Tasmania (DPIPWE). This weed was considered to be the highest
risk weed to the natural values of the creek (APPENDIX 2).
Fauna
The NEST (2014) assessment of natural values of the Cooee Creek un-named tributary
included an assessment of fauna (APPENDIX 2). This survey was done over the entire 4 kms
from the Waste Management Centre to the confluence with Cooee Creek.
This study found that the section of the creek that flows through the BWMC is suitable habita t
for the Burnie burrowing crayfish. The Spotted tailed quoll, Green and gold frog and Eastern
barred bandicoot could potentially also inhabit this zone.
Downstream of the BWMC, creek sections either passing through areas of native vegetation or
areas that have had work undertaken to improve the riparian zones showed evidence of
burrowing crayfish activity consistent with the presence of the Burnie burrowing crayfish.
Cooee Creek approximately 3 kms from the BWMC provides a well-shaded stream with pools
suitable for presence of the Giant freshwater crayfish.
The green and gold frog was considered potentially occurring in the creek areas in the vicinity
of the project site (unnamed tributary). Signs of habitation by pademelons (Thylogale
billardierii) and Tasmanian Native-hen (Tribonyx mortierii) were also noted.
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Riparian areas in proximity of the project site that are well connected to larger patches of
bushland, are expected to be used as hunting territories by the Tasmanian devil and spotted -
tailed quoll.
A Masked owl (Tyto novaehollandiae) was also sighted during the survey. Signs of bandicoot
activity were also found but it could not be determined whether it was from the Southern brown
bandicoot (Isoodon obesulus) or Eastern barred bandicoot (Perameles gunnii).
As expected, sighting of fauna was dependent on the level of creek degradation and
vegetation cover.
5.2.10 Natural Events & Hazards
Fire
Currently, the risk of fire at the BWMC is relatively low due to the operations being now limited
to waste recovery, and due to existing procedures covered by the existing EPN and
management plan for the site (Mooreville Rd Landfill Environmental Operations Manual,
Meinhardt Infrastructure and Environment Pty Ltd, April 2005). Strict management procedures
apply that include the following:
Strict control of accepted waste types (no explosives).
Site supervision during hours of operations and presence of a Caretakers’ residence
on the site perimeter.
No permission for open fires on the site; only regulated gas flames are us ed.
Appropriate training of operators for fire fighting.
Provision of fire breaks.
Provision of vehicular access on site to all fire fighting equipment.
Provision of appropriate signage.
Appropriate and regular maintenance of all fire fighting equipment.
Restricted site access.
Flooding
The 1000 year ARI flood line is assumed to be up to ~1.0 to 1.5 m above existing surface
above the current creek waterway (top of bank). The outline of the 1000 year floodplain is
shown in Figure 35. The treatment wetland will be located well above this line. The pump
station, emergency storages and infiltration swale will be located within this zone (since this is
the current status).
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Figure 35. The outline of the 1000 year floodplain (blue hatched areas)
Natural Hazards
No active or recent landslides have occurred on the site or have been mapped historically
(MRT Burnie Landslide Inventory Map, Stevenson et al 2010).
5.2.11 History of Waste Management
A summary of historical waste management activities on site that may affect the proposal is
summarised below. In the main, this information is relevant to understanding the nature of the
leachate chemistry (due to mixing with groundwater as discussed in Section 5.2.4), and the
geotechnical assessment of locating a wetland treatment system on top of the landfill cap (see
6.1.2).
Prior to development, the site contained springheads and shallow gullies and a large
swamp at the confluence of the creeks. “Stormwater” pipes were installed in the base
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of the landfill cell to collect the spring flow and surrounding groundwater seepage. The
pipes were rubber ring joined concrete pipe. Strictly speaking, the pipes form a
groundwater drainage system.
The groundwater drainage system under Stage 1 Landfill was compromised many
years ago during landfill operations. Recent (August 2015) photographic evidence
confirms that:
o For some of the manholes, holes were punched into the concrete manhole
sections to allow surface runoff to drain from the operating landfill surface,
o Some manhole shaft joints were not properly sealed, allowing leachate to seep
into the manholes.
o Manhole E shows that the liners are mis-aligned allowing seepage into the
manhole. There are also several holes in the liners.
Stage 1 Landfill was filled between 1987 and 2004, and capped in 2004/2005. Survey
data confirms the base of the manholes is about 10 m below the landfill cap. Anecdotal
commentary from the BCC Waste Team Leader at the time was that filling started
against the northern containment bund wall and progressed in a southerly and easterly
direction. When filled, a temporary cap was put on the landfill. Approval was then
obtained from the licensing authority to place a 2nd lift (3 m of waste) on Stage 1. The
2nd lift was achieved by constructing a bund wall along the northern edge of Stage 1
and filling in the same manner as the first lift: in a southerly and easterly direction
(verified by the cross section presented in Figure 4 of the Tasman Geotechnical report,
APPENDIX 6). There was no separation of waste during filling of Stage 1 (eg greens,
paper and metals) and car bodies were squashed and included in the waste.
Spreading and compaction of the waste was achieved with a 14t drott, an earthmoving
machine similar to a bulldozer, but with a front bucket. However, the degree of
compaction of the waste was minimal. The use of a compactor at the site did not
commence until close to the end of Stage 1. Hence, compaction of the waste is likely
to be poor.
Assuming poor compaction of the waste, the bulk density may be as low as 0.6 t/m3.
However, considering the inclusion of day and intermediate cover, some compaction
from the drott and the fact that Stage 1 was capped at least 10 years ago, it can be
argued that the waste density is higher. A value of 0.8 t/m3 is deemed appropriate to
assess the long term stability of the landfill.
The Stage 1 Landfill comprises two capping designs – the northern part has a rock
aggregate drainage layer while the southern part contains a Geosynthetic Clay Liner
(GCL) (visible on Figure 35 and APPENDIX 7).
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Between 2007 and 2015, the site was accepting select clay material, which was
progressively placed and stockpiled on the western side of the Stage 1 cap. Stage 2A
landfill was capped in March 2015 with the clay stockpiled on Stage 1.
5.3 SOCIO-ECONOMIC ASPECTS
As previously discussed under the Public Consultation Section (Section 4.0), the key
stakeholders that will potentially be impacted by or have an interest in the proposed project
include immediate neighbours, downstream landowners, the broader Burnie Community, the
TAFE Farm, Schools, UTAS, Cradle Coast Authority, NRM and Burnie City Council.
5.3.1 Project Socio-Economic Benefits
In addition to environmental gains, the project is expected to provide a range of social as well
as economic benefits to these key stakeholder groups.
Social Benefits
At the present, the landfill site has no broader social benefits to the local and regional
community, outside of the waste management function. The Stage 1 site is fully fenced and is
not accessible to the public. The site has a very limited biodiversity and aesthetic values, and
is not visually connected to its surroundings.
The proposed wetland system is expected to greatly enhance the aesthetic and biodiversity
values of the landfill and enable better integration of the site with its surrounding environment.
The constructed wetland system will provide an opportunity for installation of boardwalks and
other interpretative signage, and for ongoing teaching and research opportunities with lnks to
the UTAS Cradle Coast Campus and schools. This is expected to increase community
appreciation of the site and site usage, and it is anticipated that over the time (especially after
the wetland system achieves maturation) the site will be frequently utilised by the local
community.
Planting of the wetland will be undertaken with community involvement including local schools,
interested local community members and the NRM group.
Economic Benefits
The project is expected to provide several direct and indirect economic benefits on both a
local and regional scale. These include:
Freeing up capacity in the Round Hill WWTP via removal of leachate from the sewage
system for other industries. A key immediate development demand in this regard is
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expansion of the cheese processing plant by Lion, which is a lead enterprise for the
expansion of the dairy industry in the north-west coast of Tasmania.
The proposal will not have a negative effect on surrounding land values. On the
contrary, the planned the wetland and associated creek restoration and stormwater
works will enhance the values of the site and surrounding land.
Increases in environmental flows will potentially increase the irrigation capacity of the
creek system further benefiting downstream agricultural users.
Provision of employment opportunities during the system construction for the local and
wider regional community.
5.3.2 Heritage
Aboriginal Heritage
Aboriginal people are known to have lived in the region. It is recognised that all registered and
unregistered Tasmanian Aboriginal sites are protected by the State Aboriginal Relics Act 1975
and the Commonwealth Aboriginal and Torres Strait Islander Heritage Protection Act 1984.
A review of the Tasmanian Aboriginal Land Council (TALC) site register indicated an absence
of Aboriginal sites and/or artefact areas within a 2.5 km radius of the landfill site. An aboriginal
cultural heritage assessment of the area confirmed there are no aboriginal artefacts on the
landfill site (SEMF, 2002).
The landscape of the landfill site has been significantly modified by the historic agricultural
and grazing activities and more recently activities associated with landfill operations. As such
there are no Aboriginal landscape values remaining within the project area, in the form of
significant native vegetation with traditional cultural associations. The project area is assessed
as being of low archaeological sensitivity (SEMF, 2002).
European Heritage
The project must comply with the Historic Cultural Heritage Act 1995.
However, there are no listed heritage properties and/or values as no places or sites exist in
the project area that are listed on the National Heritage List, Register of the National Estate,
Tasmanian Heritage Register or the Tasmanian Historic Places Inventory.
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6.0 POTENTIAL IMPACTS & THEIR MANAGEMENT
6.1 KEY ISSUES SPECIFIC TO THIS PROPOSAL
The key issues identified as specific to this proposal are:
Potential surface water hydrology and water quality impacts.
Potential groundwater impacts and geotechnical issues.
The background to these issues is covered in Section 5.0. This section uses a risk based
assessment method to identify the potential impacts, receptors, pathways and
mitigation/management measures required (or already incorporated into the design), to
manage these risks. To assist in the assessment of surface water quality impacts, the mass
pollutant loads expected to be discharged to the infiltration Wet Forest (on site) and to the
unnamed Cooee Creek tributary, is provided, as well as a summary of geotechnical issues
pertinent to the risk profile. The hydrogeotechnical report is provided as APPENDIX 6.
The proposal is not expected to have any impacts on the groundwater aquifer, since the
proposal sits within a groundwater discharge zone with all groundwater within Stage 1
discharging via surface flows or subsurface seepage to the unnamed Cooee Creek tributary.
This has been discussed throughout the document and in detail in Section 5.2.6, and is
illustrated in the current conceptual site model (Figure 29) and the conceptual model showing
the proposed development (Figure 36).
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Figure 36. Conceptual site model – PROPOSED DEVELOPMENT SCENARIO
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6.1.1 Potential Surface Water Quality and Hydrological Impacts
The proposed design of the leachate wetland system aims to minimise direct discharge of the
treated leachate to the unnamed tributary of Cooee Creek by maximising on-site infiltration
within the last component of the system (Infiltration Wet Forest). Hence, most of the treated
leachate will discharge indirectly via subsurface infiltration to the Creek , with only flows in
excess of the infiltration capacity of the Wet Forest overflowing directly to the Creek via a
weir/cascade (i.e. during high or prolonged seasonal rainfall events).
This proposal will result in three key changes:
1. Treatment of the Stage 1 leachate to ANZECC aquatic ecosystem protection standards
prior to discharge.
2. Indirect discharge on site of highly treated leachate via infiltration in low and average
flows (<360 m3/day).
3. Direct discharge to the creek in high seasonal flows, prolonged rainfall periods which
generate above average leachate flows, and peak flows), rather than to sewer.
The proposed routing of flows and water balance is indicated in Figure 37.
Of note, the Stage 1 leachate chemistry is below the EU Landfill Directive Annex II criteria for
inert waste, meaning this would be allowable for direct release to the environment in EU
countries (see discussion in regard to this in Valencia et al 2009). This is not obviously
proposed here however provides some context as to the highly risk averse approach taken to
the treatment and discharge design.
To inform the risk assessment, an assessment of treated leachate flows and pollutant mass
loads to the infiltration forest and to the creek is provided below. Note, actual daily rainfall and
leachate data for the period 2010 – 2014 was used to generate the daily mass balance. This
dataset includes peak rainfall events. The daily mass balance assumes that once the soil
profile is saturated, all further inputs will report via overland flow to the discharge point, and
via the stormwater swale to the Cooee Creek discharge point as shown in Figure 11 and
Figure 12.
Mass load calculations were undertaken using the following inputs and assumptions:
Area of the Infiltration Wet Forest of 4,000 m2, with a 100 mm operating water depth
and additional 100 mm freeboard activated in large flow periods.
Actual (empirical) daily rainfall data and daily leachate flows for the period 2010-2014.
It is important to note that these flow data incorporate peak rainfall events that
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occurred within the 2010-2014 period, including the extreme (>80 year) 2011 summer
rain events and includes both wet years (2012, 2013) and a dry year (2014).
A conservative infiltration rate of 1*10^-6
m/s. Previous borelogs around the site (Coffey
2004, 2007 and APPENDIX 6) indicates the soils in the proposed infiltration area are
sandy clays and silty clays. The recent bore (BH26, Figure 38, drilled as part of the
geotechnical risk assessment indicated soils were silty clays near the toe of the Stage
1 northern embankment (APPENDIX 6). Weathered basalt in BH26 was encountered
at 2.5m bgl. Previous descriptions of a bore near to the Stage 1 pump station (MH1)
indicate deeper profiles with groundwater observed at ~4.5m bgl (Coffey 2007).
For nutrients, iron, manganese and zinc - concentration in the Infiltration Wetland
effluent were modelled based on the approach outlined in Kadlec & Wallace 2008 and
using mean monthly concentrations, temperature adjustments and pollutant specific
removal rate coefficients (Table 25).
For other contaminants of concern, final effluent concentrations were ass umed to have
met the set WQ targets at the outlet of the polishing wetland as outlined in Table 23
(Table 25).
Indirect Discharge Occurrences - Estimated Mass Loadings to Wet Forest
The infiltration ‘Wet Forest’ is designed as a large riparian buffer which will further attenuate
the volume of treated leachate and mass of residual nutrients and trace metals on -site, via the
following processes:
1. Infiltration and storage of water within the soil pore spaces (infiltration rate assumed at
1*10^-6,
which was recorded in bores within the proposed area).
2. Complexation of minerals with clay particles and organics .
3. Plant uptake of water and nutrients.
Treated leachate infiltrated within the site not taken up in soil storage and evapotranspiration,
will eventually join the groundwater throughflow at the contact zone of the basalt, and migrate
via subsurface flows to the creek. The model indicates that subsurface flows will be minimal
(limited to spring/winter). Due to the attenuation within the vertical soil profile (~2.5 – 4.5 m
depth) and the long lateral flow path (>100 m), the concentration of pollutants is expected to
be >90% attenuated (typical of riparian buffers), hence any subsurface discharges will be very
minor in terms of mass load.
For the purpose of this mass balance, all water in excess of ET and soil storages is assumed
to discharge via surface flows to the creek, with indirect discharges ignored at this stage. The
mass loads to the infiltration wetland are shown in Table 26, Table 27 and Figure 39.
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Figure 37. Proposed water circuit and water balance for normal (median) and high flows
MH1
ORANGE: All internal flows through wetland
YELLOW: High flows, 23L/sec max flow rate engaged when median flows exceed 20L/sec. Max 1989 m3/day
HIGH FLOW SPLITTER
BOX & SEDIMENT
DROP OUT CHAMBER
HEADER TANK/SPLITTER
LIGHT BLUE: Median flows, 20L/sec max flow rate max 1728 m3/day
DARK BLUE: All raw leachate flows to max 3600 m3/day or 43 L/sec
RED: All dilute flood flows >3600 m3/day (>80 year event) from emergency storage to swale and creek (>43 L/sec) – flows will be mixed & diluted with on-site stormwater and creek flood flows.
MH1
EMERGENCY STORAGE
GREEN: All treated flows plus rainfall via outlet pipe to infiltration wetland - max 5500 m3/day . Flows in excess of infiltration capacity overflow to max swale and creek - ~35 ML per year .INFLUENT
SAMPLE LOCATION (INF)
EFFLUENT
SAMPLE
LOCATION (EFF 1)
PURPLE: Recirculation of non-compliant flows (max 4 L/sec 350 m3/day.
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Total Phosphorus (TP) mg/L monthly quarterly monthly
Major Anions
Chloride mg/L quarterly quarterly monthly
Sulphate mg/L quarterly quarterly monthly
Major Cations
Mg mg/L quarterly quarterly monthly
K mg/L quarterly quarterly monthly
Na mg/L quarterly quarterly monthly
Metals (total)
Al mg/L quarterly
As mg/L annually
Cd mg/L quarterly
Cr mg/L quarterly
Cu mg/L quarterly
Fe mg/L quarterly All monthly
Hg mg/L annually
Mn mg/L quarterly
Ni mg/L quarterly
Pb mg/L quarterly
Se mg/L annually
Zn mg/L quarterly
All every 2 months
at INF, PRE and EFF 1
SURFACE WATER AND LEACHATE
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GROUNDWATER
YEAR 1 YEAR 2 ONWARDS YEAR 1 ONWARDS *
ANALYTICAL PARAMETERS UNIT
MONITORING FREQUENCY AT
PROPOSED SAMPLING LOCATIONS
INF (L1), PRE, SF, SSF, EFF1 & EFF 2
MONITORING FREQUENCY AT
PROPOSED SAMPLING LOCATIONS
INF (L1), EFF1 & EFF 2
MONITORING FREQUENCY AT
PROPOSED SAMPLING
LOCATION G1 (INFILTRATION
FOREST
CHEMICAL
OC/OP Pesticides
a-BHC µg/L
Aldrin µg/L
b-BHC µg/L µg/L
Chlordane µg/L µg/L
Chlorpyrifos µg/L µg/L
d-BHC µg/L µg/L
Diazinon µg/L µg/L
Dieldrin µg/L µg/L
Dimethoate µg/L µg/L
Disulfoton µg/L µg/L
Endosulfan I µg/L µg/L
Endosulfan II µg/L µg/L
Endosulfan sulphate µg/L µg/L
Endrin µg/L µg/L
Endrinaldehyde µg/L µg/L
Ethylparathion µg/L µg/L
Famphur µg/L µg/L
g-BHC µg/L µg/L
Heptachlor µg/L µg/L
Heptachlor epoxide µg/L µg/L
Hexachlorobenzene µg/L µg/L
Malathion µg/L µg/L
Methyl parathion µg/L µg/L
Phorate µg/L µg/L
pp'-DDD µg/L µg/L
pp'-DDE µg/L µg/L
pp'-DDT µg/L µg/L
Sulfotep µg/L µg/L
Thionazin µg/L µg/L
All annually at INF, EFF 1 and EFF 2 All annually at INF and EFF 1
SURFACE WATER AND LEACHATE
All monthly
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GROUNDWATER
YEAR 1 YEAR 2 ONWARDS YEAR 1 ONWARDS *
ANALYTICAL PARAMETERS UNIT
MONITORING FREQUENCY AT
PROPOSED SAMPLING LOCATIONS
INF (L1), PRE, SF, SSF, EFF1 & EFF 2
MONITORING FREQUENCY AT
PROPOSED SAMPLING LOCATIONS
INF (L1), EFF1 & EFF 2
MONITORING FREQUENCY AT
PROPOSED SAMPLING
LOCATION G1 (INFILTRATION
FOREST
CHEMICAL
Polycyclic aromatic hydrocarbon
(PAH)
Acenaphthene µg/L µg/L
Acenaphthylene µg/L µg/L
Anthracene µg/L µg/L
Benzene µg/L µg/L
Benzo[a]anthracene µg/L µg/L
Benzo[a]pyrene µg/L µg/L
Benzo[b&k]fluoranthene µg/L µg/L
Benzo[ghi]perylene µg/L µg/L
Chrysene µg/L µg/L
Dibenzo[ah]anthracene µg/L µg/L
Fluoranthrene µg/L µg/L
Fluorene µg/L µg/L
Indeno[123-cd]pyrene µg/L µg/L
Naphthalene µg/L µg/L
Phenanthrene µg/L µg/L
Pyrene µg/L µg/L
Monocyclic aromatic hydrocarbon
(MAHs)
Ethylbenzene µg/L µg/L
om&p Xylene µg/L µg/L
Toluene µg/L µg/L
Total BTEX µg/L µg/L
Other
Cyanide total µg/L quarterly quarterly quarterly
PCB µg/L µg/L annually annually annually
MICROBIOLOGICAL
E.coli org /100 mls quarterly quarterly quarterly
Notes
** COD test method detection limit to be lowered to reflect range of values for leachate INF and EFF.
All annually at INF, EFF 1 and EFF 2 All annually at INF and EFF 1
All annually at INF, EFF 1 and EFF 2 All annually at INF and EFF 1
* Frequency and parameters to be reviewed following the results of the first year of operation with a view to decrease/increase sampling frequency and potentially delete unecessary parameters.
SURFACE WATER AND LEACHATE
All monthly
All monthly
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7.3 GEOTECHNICAL MONITORING
7.3.1 Construction Monitoring - Pre, During and Post Construction
General settlement of the Stage 1 landfill area will be monitored via the installation of (semi)
permanent topographical survey markers within the extent of the proposed wetlands and
beyond. These markers will be checked by a certified surveyor pre (two weeks prior to works),
during works, and post construction works (for two months) on a weekly basis. The exact
number and location of markers will be established during detailed design. Nominally at least
eight markers covering the wetland extent are envisaged to cover surface flow wetland,
subsurface flow wetland, outer perimeter buns and potentially pipe and pit infrastructure .
7.3.2 Ongoing Settlement Monitoring
In order to monitor potential settlement and changes to design levels in the wetland area, a
minimum of four (4) (semi) permanent topographical survey points will be set on the wetland
bunds to the north, east, west and south of the wetlands and monitored monthly by a certified
surveyor for the initial 6 months. After six months and provided that negligible settlement has
occurred, monitoring can be reduced to annually. The northern geotechnical monitoring point
will be located on the containment bund adjacent to the site boundary. The exact coordinates
of the points will be determined during the detailed design stage.
7.3.3 Wetland Liner Leakage Monitoring
Any leakages in the wetland liner and Stage 1 landfill cap will simply be collected by the
leachate system at the base of the waste. Contiguous flow monitoring at the wetland influent
(INF) and wetland effluent (EFF1) will allow for a water balance to be carried out for the
wetland and determine whether water losses (beyond evapo-transpiration) are occurring.
Where a gravel drainage layer above the clay capping is present, such as the northern part of
Stage 1, any leakage through the wetland would flow laterally through this gravel layer and
directed to the phytoremediation swale. After heavy rainfall events, visual checks of flows in
the infiltration swale are to be undertaken and if abnormal flows are present beyond those
expected from rainfall, further investigation will be required to ascertain the origin of flows, and
would include testing the water in the phytoremediation swale.
The existing piezometers installed along the landfill cap for monitoring of leachate standing
levels will also be retained where possible and will continue to be monitored to assist in
assessing potential wetland leakages.
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7.4 MAINTENANCE & SYSTEM HEALTH MONITORING
7.4.1 Ongoing Maintenance Tasks
Ongoing maintenance tasks refer to those tasks which will be undertaken on a regular
(weekly, monthly or quarterly) basis. The ongoing maintenance tasks will be fully identified in
a Operating and Maintenance Manual to be done at a later stage, however as a minimum
these will include:
Maintenance Tasks for Infrastructure:
o Equipment (e.g. pumps, manholes, liner, concrete structures) – will be
inspected and maintained as per manufacturer’s specifications, and as part of
routine maintenance quarterly or biannually and after peak rainfall events.
o Operators Inspection Checklist (to be prepared as part of the Operating
Manual) – will be completed after each maintenance activity and any issues
recorded and actioned.
o Sediment levels – will be monitored quarterly and removed from sediment
chambers and pre-filter as required.
o Pipe work and weirs – will be checked for leaks and blockages weekly or
monthly and following peak events. Pipes will be cleaned periodically to ensure
they are free of any obstructions which have the potential to cause clogging.
o Manholes and valves – will be inspected to ensure function is correct and to
ensure accessibility.
o Access track and embankments –will be inspected for damage, erosion, and
weeds. Tracks will be maintained as required to ensure they remain clear and
accessible.
o Site Fencing – will be inspected quarterly to ensure public safety.
o Rock-lined distribution zones – will be inspected and cleaned as required.
Maintenance Tasks for Wetland Vegetation:
o Weed control activities – will be undertaken on a quarterly or bi-annual basis
throughout the wetland.
o Plant health, density and diversity – will be monitored on a bi-annual basis
throughout the wetland and appropriate management measures undertaken to
replace plants, undertake weed control works or apply conditioners etc if
required.
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Maintenance Tasks for Potential Wetland Leakage:
o After heavy rainfall events, visual checks of flows in the infiltration swale will be
undertaken. If abnormal flows are present beyond those expected from rainfall,
further investigation will be undertaken to ascertain the origin of flows.
o The existing piezometers installed along the landfill cap for monitoring of
leachate standing levels will also be retained (where possible) and will
continue to be monitored to assist in assessing potential wetland leakages.
o If leakages due to issues of liner integrity are identified, the relevant section of
the wetland will be taken off-line and repaired.
Condition Assessments of the Creek Tributary - BCC, with the consent of the
neighbouring property owner, will undertake annual condition assessments of the
creek tributary from the treated leachate discharge point to Three Mile Road for the
first 3 years after construction of the treatment system. This will be to ensure the
anticipated positive creek benefits associated with improved environmental flows and
biodiversity improvement works are realised.
7.4.2 Scheduled Maintenance Tasks
Scheduled maintenance tasks are those tasks which will be scheduled annually or 3 to 5
yearly. The scheduled maintenance tasks will be fully identified in an Operating and
Maintenance Manual to be done at a later stage, however as a minimum these will include:
Maintenance Tasks for Wetland Vegetation.
o Sediment – will be removed and disposed of from pre-filter and manhole
chambers;
o Biomass thinning – will be undertaken on a 3 to 5 year harvesting plan; and
o Supplementary planting – will be undertaken in bare areas if required.
Maintenance Tasks for Landfill Settlement
o If required, repairs to wetland bund heights will be undertaken to maintain
flows and freeboard capacity. This will be achieved by adding fill material and
potentially extending the liner along any sections of the wetland bunds that
have settled below the critical 200 mm freeboard level. Weirs/pipes may
require adjustments (e.g. alter weir board positions) however this is not
envisaged as likely.
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7.5 REPORTING
In line with the current EPN prescription, a report with the results of the water monit oring,
including sampling locations, sampling methods, chain of custody documentation and
comparison of results against the site specific treatment criteria and the Australian Water
Quality Guideline for Aquatic Ecosystems (ANZECC, 2000) Ecosystem Condition 2 (level of
protection 95% species) trigger values applying to lowland streams will be prepared and
submitted to the EPA on a quarterly basis. The results of the geotechnical monitoring will also
be submitted to the EPA within the same report.
8.0 DECOMMISSIONING & REHABILITATION
The Burnie Waste Management Centre is expected to have a long life span as a waste
recovery centre (more than 20 years), hence the wetland itself will continue to be managed as
part of the site alongside this. At some point, the data on water quality discharge from the site
may indicate that the raw leachate is acceptable for direct infiltration on-site.
In the longer term at site closure, the wetland could be repurposed as a stormwater treatment
system, eventually opened to the public as a recreational biodiversity reserve.
9.0 COMMITMENTS
A consolidated set of commitments is provided in Table 34.
10.0 CONCLUSION
This DPEMP has complied with all the requirements of the project specific guidelines. The
relevant sections are summarised in Table 35.
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Table 34. Commitments table for the Burnie Treatment Wetlands proposal
Design &
ApprovalsConstruction Operation
1 Undertake works to separate the stormwater from the MH1 leachate chamber BCC
2 Limit the placement of the wetland system to at least 10 m from the landfill crest. BCC
3 Ensure appropriate freeboard to accommodate the 1000 year rainfall event (182 mm) BCC
4 Limit the height of bunds to <2 m to prevent excessive settlement BCC
5 Use a LLDPE liner to reduce wetland seepage risks BCC
6 Construction of an emergency storage tank and recirculation system and operate for non-compliant water BCC
7 Construct a new connection to sewer maintained in case of non-compliance, as final contingency. BCC / TASWATER
8Retain wetland designer during construction / contract management phases to ensure quality control of all system
components (e.g. liner, hydraulics, planting, etc) and safeguard management elements are constructed as per design.BCC
9Ensure interception and treatment of extreme storm event leachate seepages that may occur along the northern
embankment, within a phytoremediation swale.BCC
10Establish a new compliance monitoring point at the creek discharge point and monitor flows (continuous, on-line) and
pollutants as shown in Table 31, when discharge events occur.BCC
11Establish a performance monitoring point at the polishing wetland outlet and install on-line flow and monitoring sufficient
to determine recirculation requirements (as shown in Table 33).BCC
12 Undertake sampling in accordance with the proposed monitoring schedule shown in Table 33. BCC
13Set aside an appropriate maintenance budget to be include in OPEX for the life of the wetland, to ensure that all required
maintenance activities are done appropriately and with the required frequency.BCC
14Develop Operation and Maintenance Plans which detail the required maintenance activities and frequencies and ensure
their appropriate implementation.BCC
NO. COMMITMENT
TIMING PHASE
RESPONSIBILITY
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Table 34 (cont.). Commitments table for the Burnie Treatment Wetlands proposal
Design &
ApprovalsConstruction Operation
15Ensure Construction Mangement Plans contain practices for managing environmental risks and safety risks during
construction works.BCC
16 Ensure Construction Management Plans comply with specifications and policies and sign off accordingly. BCC
17Update existing risk management plans to include responses to incidences potentially connected with the treatment
system. This will include incidence response for any on site ponding and mosquito management.BCC
18 Install 4 survey markers and undertake forthnightly monitoring of settlement levels across the landfill pre-during and post
construction for several months.BCC
19 No clearing of native vegetation. BCC
20Use of sediment controls (traps, sediment curtains) during creek enhancement works, and reuse of sediment within
landfill area.BCC
21Use of locally native species in the treatment system to avoid invasive species entering the creek and to enhance
biodiversity.BCC
22Undertake restoration works in the immediate unnamed creek discharge area to reduce weeds, enhance riparian
vegetation, improve habitat and reduce erosion.BCC
23 Undertake an annual condition assessment of the unnamed tributary to Three Mile Rd. BCC
24 Implement an ongoing weed management program within the wetland system and creek discharge areas. BCC
25Provide controlled site access and interpretative walks/signage to enable community use of the proposed system for
education and research.BCC
26 Undertake annual monitoring of settlement levels across the landfill. BCC
27Undertake appropriate training of staff responsible for system monitoring & maintenance, including preparation of user-
friendly management and maintenance plans.BCC
NO. COMMITMENT
TIMING PHASE
RESPONSIBILITY
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Table 35. Summary of compliance with specific guidelines
No. Summary of response
2.2.3 Proposed System Summary Includes summary of design objectives and criteria.
2.2.4 System Components & Processes
Includes detailed description of system components and processess, including
descriptin of creek discharge regime, connection infrastructure to existing
TasWater sewer network and construction material details.
2.2.6 System OperationHours of system operation, vehicualr movements during construction &
commisioning, and operational regime.
2.2.4 System Components & Processes Provides detailed description of system components.
2.2.5 Wetland Sizing/Capacity
Provides information regarding the required treatment area, operating
depth/volumes, hydraulic loading rates and hydraulic retention times are shown
for each component (Table 1).
3 2.2.7Proposed Stormwater & Creek
Enhancement Works
Provides a brief description of proposed stormwater and creek enhancement
works expected to tie in with the proposed leachate treatment works (Figures
11, 12).
4 2.2.10 Precedent ProjectsGlobal examples of landfill remediation projects for various 'soft' uses (i.e. with
relatively lightweight loads) with minimal or no geotechnical improvements.
5 2.2.3 Proposed System Summary Includes summary of design objectives and criteria.
6 6.3.6 Pests, weeds and diseasesProvides summary of weed/pest management responses during the system
construction and operation.
7 2.2.8 Construction Provides an estimate of the raw materials that will be required for the proposed
system and likely material sources (Table 4).
6.2.4Proposed Management
Measures
6.38 Sediment
REQUIREMENTS RESPONSE
Brief description of the proposed stormwater and creek enhancement works at the BWMC
site, with particular reference to the separation of site stormwater from the
leachate/groundwater system.
Section
2.2 Construction
Measures designed to prevent the introduction or spread of introduced plant species,
weeds, pests and diseases (such as phytophthora cinnamomi ) during construction works.
2.1 Proposal description - General
Detailed description of the wetland treatment system and associated infrastructure,
including size, volume, and design criteria of the wetland ponds, wetland liner, media
and species of flora, leachate collection and transfer infrastructure, overflow storage
ponds, infiltration area and discharge swale/outlets, and connection infrastructure to
existing TasWater sewer network.
1
Description of Specific Requirements
Description of treatment process and treatment capacity (i.e. kL per day), including
residence time required for removal of contaminates and design features to allow for
draining, maintenance and variations in flow.
2
Description of precedent projects, i.e. on‐site wetland leachate treatment facilities on
top of landfills. Where information is available, provide a summary of the issues’ and
success’ of these projects.
Design criteria for the proposed infrastructure in relation to flood risk, e.g. 1 in 100 year
event.
Estimates of the quantities of major raw materials required for construction activities
(e.g. clay, sand, aggregate) and their likely sources.
Details of management practices for areas disturbed during the construction phase to
prevent sediment movement into watercourses. 8
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9 2.2.9 Commissioning Provides a list of key commissioning items , and detail regarding the timing and
end of commissioning period (Table 5).
10 2.2.1 General Figure 2. Land boundary, site layout and location points
11 2.2.1 General Figure 3. Site Plan showing landfill stages.
12 3.1
On‐Site Treatment vs
Decommissioning & Remediation
vs Trade Waste Discharge
Summary of the assessment process that focused on the suitability of the
following options:
1) Do nothing and continue to discharge to TasWater Sewerage System under a
Trade Waste Agreement (TWA) with TasWater (Base Case).
2) Remove waste from Stage 1 Landfill and develop and dispose to new waste
cell on site (Stage 2B/C).
3) Remove waste from Stage 1 Landfill, transport and dispose to an alternate
landfill (e.g. Port Latta or Dulverton).
4) On-site treatment.
3.2Evaluation of Reuse vs Disposal
Options
Summary of the assessment process that focused on the suitability of the
following options: 1) On-site reuse , 2) Discharge within the site or above the
landfill site, and 3)Off site discharge to the downstream unnamed tributary of
Cooee Creek.
3.3Evaluation of Treatment
Approaches & Technologies
Summary of the assessment process that focused on a suitability of leachate
management approaches and technologies commonly applied on landfill sites
(e.g. physico-chemical, advanced filtration and biological systems), including
detailed evaluation of three shortlisted technologies (RO, MBR, constructed
wetlands).
14 3.4Assessment of Treatment
Wetland Locations
Summary of the assessment process that focused on the he feasibility of four
alternative locations for the construction of the proposed the on-site treatment
wetland system
5.1.2 Land Use & Planning History
5.2.11 History of Waste ManagementA summary of historical waste management activities on site that may affect the
proposal.
Appendix 13.Chronology of the Waste
Management Activities On Site
2.3 Commissioning
A description of the commissioning of the wetland treatment facility and associated
infrastructure.
2.3 Site plan
A map delineating the boundary of the Land on which the activity will take place.
A site plan showing historical landfill, e.g. stages 1A, 1B, 1C and 2A, extents and
features.
3 Project Alternatives
A discussion of the alternatives for leachate management (e.g. treatment / full
decommissioning and remediation of the landfill / continuing with the trade waste
discharge to sewer, etc).
An assessment of the options for onsite leachate treatment, with reasons for the
preferred treatment system (e.g. physic-chemical systems, filtration, biological
treatment, etc).
13
An assessment of the options for wetland treatment location, with reasons for the
preferred location.
5.2 Existing environment – Environmental aspects
History of waste management activities on site, e.g. stages 1A, 1B, 1C and 2A, including a
description of all elements of the landfill that may affect the proposal. 15
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16 5.2.6 Groundwater
Provides detail regarding the existing hydrogeological context and groundwater
quality. Includes summary of groundwater quality data and a conceptual site
model illustrating the interactions between groundwater with leachate and
surface flows .
17 5.2.4 Leachate (Current)Provides detail regarding the leachate flows, leachate quality, and calculations
on discharge (mass loads) of key pollutants to TasWater sewer (Table 14).
18
Provides detail regarding the nature and location of the leachate seepage
including data on leachate seepage chemistry for the 3 sampling events in 2013
(Table 15).
19
Provides summary of findings of soils investigation within the leachate seepage
undertaken in April 2014 (Table 16) and the extent of leachate seepage that
occurred in August 2013.
20 5.2.7 StormwaterProvides the estimates regarding the current stormwater mass loads to the
Creek (point source discharge) (Table 19).
21
Provides detail regarding the current Protected Environmental Values (PEVs) ,
EPA Draft Water Quality Objectives for Cooee Creek and proposed Water Quality
Targets for discharge to Cooee Creek tributary (Table 23).
22Provides information regarding the known abstraction points along Cooee Creek
.
23
24
25
26
27
This section: 1) Provides details regarding the nearest sensitive receptors to the
site; 2) Explains why the proposed wetland treatment system will not generate
point source odour emissions ; 3) Summarises the history of complaints
regarding odours for the existing site (documented in the annual reporting since
2004.
6.3.1 Air Quality
Results of ambient groundwater survey and modelling to define the local groundwater
environment, including groundwater quality and description of the interaction between
groundwater, leachate and surface water. The description must include concentrations of
key groundwater quality parameters.
Description of leachate quality and quantity currently discharged to TasWater’s sewage
network, including mass loadings of key effluent parameters.
Description of leachate seepage, including the mechanisms driving the seepage, and
seepage quantity and quality, including mass loadings of key water quality parameters.
Delineation and characterisation of the leachate seepage area and extent of any soil
contamination.
5.2.5 Leachate Seepage
Identification of current Protected Environmental Values (PEVs) at the proposed
discharge location and within the expected zone of impact, including Cooee Creek. Water
Quality Objectives (WQO’s) should be proposed in relation to all identified PEVs.
Details of the water use within the catchment of the receiving environment (i.e. the
unnamed creek and Cooee Creek).
5.2.8 Cooee Creek and its Tributary
Results of the ambient water quality survey, including mass loadings of key water quality
parameters across a range of flow conditions.
6.1 Air Quality
Provide a map of the area showing the existing and proposed facility and any sensitive
receptors that could be affected by odour emissions from the proposed facility.
Describe and mark the locations (on a site map) of all potential sources of odour
emissions (i.e. wetland ponds (types), infiltration areas etc), and under what conditions
emissions may occur, e.g. commissioning, normal operation, during maintenance etc.
Discuss the potential for odour emissions from the wetland treatment facility to cause
environmental nuisance, including under worst case or upset conditions.
Identify and discuss measures to be implemented (as appropriate) to mitigate any
impacts that may cause environmental nuisance.
Provide a history of odour complaints received in relation to the existing site and the
likely causes.
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28
29
30
31 6.2Hazard and Risk Assessment of
Key Issues
This section provides an assessment of potential environmental risks associated
with potential discharge of leachate (un-treated or partially treated leachate) to
the creek, or ponding on site, and impacts on the key relevant receptors,
including downstream water users.
32 5.2.8 Cooee Creek and its TributaryProvides detail regarding the proposed Water Quality Targets for discharge to
Cooee Creek tributary (Table 22).
33 5.2.8 Cooee Creek and its TributaryProvides detail regarding the proposed Water Quality Targets for discharge to
Cooee Creek tributary (Table 23).
34 8.0Decommissioning &
Rehabilitation
35 4.1.2 Consultation with TasWaterTaswater will undertake this assessment. They have indicated that this is
unlikely to be an issue.
This section contains the findings of an assessment of flows and pollutant mass
loads to the infiltration forest and to the creek, and includes: 1) Identification of
discharge pathways and occurrence of discharge events, 2) Indirect discharge
occurrences - Estimated mass loadings of key pollutants to wet forest; 3) Direct
discharge occurrences - Estimated Mass Loadings to Creek (i.e. creek volumetric
discharges and mass load discharges in each month and annual mass load
discharges for select pollutants); 4) Comparison of total annual discharge to the
Creek in a dry year (2014) and wet years (2012, 2013) and corresponding mass
loadings of key pollutants (Table 29 and Table 30).
Surface Water 6.1.1
Provide an assessment of the capacity of the sewerage system to receive the leachate
discharge, as part of contingencies measures.
Demonstrate that the proposed discharge(s) will satisfy the requirements of the State
Policy on Water Quality Management 1997, including compliance with any relevant
emission limit guidelines.
Recommend emission limits and trigger levels. These should be based on the character of
the receiving environment (e.g. water quality, proposed WQOs, seasonal flow).
Provide an estimate of the required life of the water treatment system (based on the
breakdown processes within the landfill), and the water quality criteria that need to be
met before the wetland system can be considered redundant (which may be based on the
quality of receiving environment, ratified WQOs, mass-loads of key contaminants etc).
6.2 Surface Water
Water balance for the site, detailing estimates of seasonal discharge to the receiving
environment, incorporating seasonal infiltration capacity and high flow/stormflow
management regimes
Identification of the discharge point from the activity to the surface water receiving
environment.
Expected quality of discharge to the surface water receiving environment (i.e. unnamed
creek), including annual mass loadings, and with comparison to ambient water quality.
The likely occurrence of discharge events to the surface environment should be clearly
understood from the water balance.
Discussion of the potential for the discharge to cause environmental impact. This should
include consideration of typical and plausible worst case situations, seasonal variations,
and potential for impact to downstream water users.
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5.2.6 GroundwaterMass loads to the infiltration wetland are shown in Table 26. Note, this DOES
NOT report to groundwater but discharges to the Creek via sub-surface flows.
6.1.1Potential Surface Water
Impacts
5.2.5 Leachate Seepage Describes the quality and estimate of volumes
2.2.4System Components &
Processes
Describes the phytoremediation swale proposed to intercept ad treat leachate
seepage events.
38 5.2.6 GroundwaterThere is no potential given it is a groundwater discharge zone. All flows
eventually report to the Creek (conceptual site model - Figure 28).
2.2.4 System Components &
Processes
6.2Hazard and Risk Assessment of
Key Issues
40 6.1.3 Potential Geotechnical Impacts Results and relevant information summarised in these two sections.
6.2Hazard and Risk Assessment of
Key Issues
Appendix 6 Hydro-geotechnical report (Tasman Geotechnics, August 2015)
41 7.3 Geotechnical Monitoring
Discussion of the potential for the treated discharge to the groundwater environment,
including the leachate seepage, to cause an environmental impact. This should include
consideration of typical and plausible worst case situations, and potential for impact to
the surface water and downstream water users.
A groundwater monitoring and reporting program must be developed, incorporating
appropriate mechanisms to monitor for wetland leakage, landfill cap settlement and loss
of landfill integrity.
Contingency measures to ensure protection of the receiving environment (i.e. the
groundwater, surface water and downstream water users) should treated leachate
exceed proposed trigger levels (see section 6.2) (e.g. collection and re-circulation of
treated leachate through wetland facility).
The expected quality and quantity of leachate seepage, and measures to manage the
seepage.
Characteristics of the effluent following treatment, including mass loadings of key
pollutants and the expected quality and quantity discharged to the groundwater
environment via the infiltration areas.
6.3 Groundwater & geotechnical issues
36
37
39
Results of the geotechnical investigations and modelling, incorporating a discussion(s) of
the potential for wetland leakage, landfill cap settlement and loss of landfill integrity
(including containment bund), their likely impact on the receiving environment, and
details of management strategies/contingency measures to mitigate the potential impact
(as appropriate).
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42 6.3.3 Waste Management
43
44
45 Appendix 2NEST Natural Values
Assessment Report, 2014
Not quantitatively assessed but commented on in this Section and NEST report .
Increased flows are expected to improve habitat quality for the key fauna.
46 7.0 Monitoring & Review
47
48 7.3Maintenance and system health
monitoring
Monitoring programs to ensure the proper functioning of the wetland and infiltration
system and protection of the environment on an ongoing basis.
Details of the monitoring programs
Description of maintenance regimes to ensure the proper functioning of the wetland and
infiltration system on an ongoing basis.
Description of the potential changes to the flow regime of the unnamed creek and Cooee
creek, with particular regard to water levels, and the potential impact on Burnie
Burrowing Crayfish (Engaeus yabbimunna ) populations downstream of the development.
5.2.8 and
Appendix 14.Cooee Creek and its Tributary
7.0 Monitoring and maintenance
6.5 Waste Management
Description of the management of wetland sludge/bio-solids generated on site.
6.7 Biodiversity and nature conservation values
Results of surveys for any rare, threatened, endangered and locally endemic species that
will potentially be impacted by the proposal.
Identify any freshwater ecosystems of high conservation management priority using the
Conservation of Freshwater Ecosystem Values (CFEV) database (accessible on the internet
under water.dpiw.tas.gov.au/wist/). The scope of investigation should encompass the
vicinity of the proposed development where there is likelihood of alteration to the
existing environment. The specific CFEV information used for DPEMPs should be
Conservation Management Priority Potential which is appropriate for Development
Proposals.
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REFERENCES
Asian Regional Research Programme on Environmental Technology (ARRPET) (2004). State
of the Art Review Landfill Leachate Treatment. Asian Institute of Techno logy, Thailand and
Tongji University, China.
Australian and New Zealand Environment and Conservat ion Council and Agriculture and
Resource Management Council of Australia and New Zealand (ANZECC, 2000) National
Water Quality Management Strategy No. 4: Australian and New Zealand Guidelines for Fresh
and Marine Water Quality (October 2000).
Bouazza A and Kavazanjian E (2001). Construction on former landfills. Proceedings 2nd ANZ
Conference on Environmental Geotechnics, Newcastle, 467-482.
Carey, P.L., Drewry, J.J. Muirhead, R.W. & Monaghan, R.M. (2004). Potential for nutrient and
faecal bacteria losses from a dairy pasture under border-dyke irrigation: a case study.
Proceedings of the New Zealand Grassland Association 66: 141–149.
Carex apressa ' Tall Sedge'Erect clump forming perennial sedge 0.5-1.2m height. Width 1.0m. Evergreen with fast growth rate Suits most soils.
Flowering in Spring and Summer.
Carex fascicularis ' Tassel Sedge'Erect clump forming perennial sedge 0.5-1.0m height. Width 1.0m. Evergreen. Evergreen with fast growth rate Suits most
soils. Full sun to part shade. Flowering in Spring and Summer.
Carex longebrachiata 'Drooping Sedge' Tussock forming sedge to 0.6 metres with long arching flower stems.
Carex tasmanica 'Curly SedgeErect clump formimg perennial sedge 0.4m height. Width 0.4m. Evergreen. Evergreen with fast growth rate Suits most
soils. Flowering in Spring and Summer. Tasmanian threatened species.
Carex tereticaulis ' Hollow Sedge'Erect clump forming perennial sedge 1.0-1.8m height. Width 1.0m+. Evergreen. Evergreen with fast growth rate. Prefers
clay soils . Flowering in Spring and Summer.
Chorizandra enodis Perennial sedge 0.5- 1m. Very narrow blue-grey to dull green cylindrical culms. Small black flowerball seedheads.
Cyperus gunnii ' Flecked Flatsedge' Tall, tufted perennial sedge to 150cm, with short thick rhizome. Culms trigonous to terete.
Cyperus lucidus ' Candelabra Sedge'Robust perennial sedge up to 1.3 m. The leaves are thick and glossy. The flowers form an umbrella-l ike head which is
bright red when young, turning red-brown as it matures.
Eleocharis sphacelatus ' Tall Spike Rush' Perennial aquatic with stout rhizome. Culms terete to 5 m high. Permanent water.
Gahnia filum 'Chaffy Saw Sedge' Dense tufted perennial to 1.2 metres. Flowers in spring/summer. Tasmanian Bush Tucker.
Gahnia grandis 'Cutting Grass'Large tussock with plume-like flowering heads to 3.5 metres. Grass-like leaves, cutting edges. Flowers in spring/summer.
Isolepis fluitans ' Floating Clubsedge'Slender, aquatic or dry land perennial up to 15cm height.Erect and tufted, spreading or submerged. Use for ponds, wet
areas and water courses. Semi shade. Pale green or straw coloured flowers in spring/summer.
Isolepis inundata ' Swamp Clubsedge'Tufted perennial rush with stiffly erect or arching stems. Deep glossy green foliage. Purple-brown flowerheads
spring/summer. Most soil types and condition.
Isolepis stellata Tufted annual, grass-like or herb (sedge), 0.02-0.1 m high, spikelets 3-8, in a dense globular cluster; Flowers yellow-
green, Sep to Dec or Jan. Grey, black peaty or orange clayey sand, loam, sandy clay.
Juncus amabilis 'Hollow Rush'Densely tufted perennial rush 0.2-1.2m height. Width 0.2 -0.5m. Spreading from underground stems. Green flowers in
Summer. Best in seasonally moist to inundated soils.
Juncus astreptus ' Rigid Rush'Rhizomatous perennial forming tight clumps 0.6-1.0m height. Brownish green flowers in Summer. Most soils -well
Juncus sarophorus ' Broom Rush'Tufted perennial rush 0.7-2.0m height. Width 0.5-1.0m. Spreads from underground stems. Straw coloured flowers in
Summer.
Schoenoplectus tabernaemontani ' River Club Rush' Creeping rhizomatous perennial sedge, 1-3.0 m height. Straw coloured flowers in Summer.
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INFILTRATION 'WET FOREST' & WETLAND BUNDS
Rushes and Sedges
Eleocharis acuta ' Common Spike Rush' Perennial sedge with creeping rhizome. Culms terete. 0.3 - 0.5m high. Seasonal wetlands.
Gahnia grandis 'Cutting Grass' Large tussock with plume-like flowering heads to 3.5 metres. Grass-like leaves, cutting edges. Flowers in spring/summer.
Gymnoschoenus sphaerocephalus ' Button Grass'This species is the dominant species of most lowland sedgelands on wet peat in Tasmania. It forms large, dense clumps
of long, narrow, yellow-brown leaves with long, cylindrical stems, each bearing a spherical terminal head of flowers.
Isolepis stellata Tufted annual, grass-like or herb (sedge), 0.02-0.1 m high, spikelets 3-8, in a dense globular cluster; Flowers yellow-
green, Sep to Dec or Jan. Grey, black peaty or orange clayey sand, loam, sandy clay.
Poa labillardierei ' Tussock Grass'Dense perennial tussock grass, common in open forests particularly in moister areas on southern slopes or in gullies
and along watercourses, on loamy soils. Suitable to clay soils. Si lver.
Xyris muelleri 'Yellow-eyed Grass'Leaves more or less spirall ing. Flowers yellow, lasting more than one day, early summer. Tasmania, in moist soil at
margins of streams and ponds.
Herbs
Billardiera longiflora 'Climbing Blue Berry'
(Climber)
Ornamental twiner grows to ~3m tall. Partial or full shade. Flowers spring and summer, producing creamy green bell-
shaped flowers that are tinged with purple. Suitable to clay soils.
Chrysocephalum apiculatum Varies considerably in form, 0.2 - 1 m in height, Suitable in clay soils. Yellow flowers.
Dichondra repens 'Kidneyweed' Fast-growing groundcover. Leaves are small and kidney shaped. This plant has a creeping habit and forms a thick mat.
Diplarrena moraea 'White Flag Iris' Perennial small herb which forms thick clumps with long narrow leaves and white flowers at the ends of slender stems.
Acacia myrtifolia 'Red-stemmed wattle'Shrub 1 - 2 m tall by 1-2 m wide. The phyllodes are ell iptic and usually slightly curved. The cream flower clusters are
globular in shape and occur on short racemes from the leaf axils in spring. Suitable to clay soils.
Acacia verticillata 'Prickly Moses'Variable height; generally rounded shrub. Phyllodes are dark green, spine-like, to 2 cm, in whorls around the stem. Pale
yellow flowers in short spikes. Yellow flowers. 5-10m. Suitable to clay soils.
Banksia marginata ' Silver Banksia'Medium shrub to 2 m tall. Leaf upper surface dark green with the lower surface white and hairy. Flowers pale yellow,
densely packed in cylindrical spikes up to 100 mm long. Suitable to clay soils.
Bauera rubioides ' Dog Rose' Scrambling shrub to 2 m high, stems extensively branched. Pink flowers. 0.3-1.5m.
Bursaria spinosa ' Prickly Box' Evergreen shrub <2 m tall, shrub or small tree <5 m tall or tree 5-10 m tall. Suitable to clay soils.
Bossiaea prostrata 'Creeping Bossiaea' Small (0.5m) prostrate shrub with yellow flowers.
Correa alba 'White Correa' Small shrub with grey foliage and white flowers. Grows to 1.5m.
Correa lawrencianaGrows to between 0.6- 9m in height, and has leaves with a shiny, dark-green upper surface. Flowers winter- spring,
typically yellow-green. Suitable to clay soils.
Daviesia latifolia ' Hop Bitter-pea' Shrub 1- 3 m with large leaves and clusters of yellow and brown pea flowers produced between Sept-Dec.
Daviesia ulicifolia Grows to 2m with yellow / red pea flowers.
Dillwynia cinerascens ' Parrot Pea' Compact shrub to 0.3-1.5m. Masses of yellow & red flowers (appearing orange)in spring.
Dillwynia glaberrima Small shrub ~1.5 metres high by 1m wide. Yellow / red flowers forming in spring.
Epacris impressa Shrub to 1-1.5m with stiff branches. Pink / red bell shaped flowers.
Hibbertia procumbens A prostrate and spreading shrub, with yellow flowers.
Leptospermum lanigerum ' Woolly Tea-Tree' Large, spreading or erect shrub, Flowers are white and appear in early summer. Suitable to clay soils.
Leptospermum scoparium Compact shrubup to 2 m tall. Leaves are variable in shape and size. White flowers, occasionally tinged with pink and
rarely red, 1 cm in diameter, occur in spring and early summer.
Leucopogon parviflorus 'Currant Bush' Erect shrub or small tree, 120–500 cm high; branchlets finely pubescent. White flowers. Suitable to clay soils.
Lomatia tinctori Small shrub to 2 m, spreading through suckers. Cream or white flowers in summer. Suitable to clay soils.
Olearia lirata 'Daisybush' Shrub to 4 m high with greyish-white branchlets and white flowers.
Oxylobium ellipticum 'Golden Rosemary' Erect to procumbent shrub to ≥ 2 m high. Yellow flowers spears. Suitable to clay soils.
Pimelea linifolia Small, erect shrub to 0.5-1.5m, with l inear leaves. Flowers usually white or very pale pink he species occurs on a range
of soils from sands to clays.
Tasmannia lanceolata 'Mountain Pepper'Tall evergreen shrub to small tree up to 10 m high. The trunk is straight, with many branches arising at acute angles.
Suitable to clay soils.
Tetratheca pilosa 'Hairy Pink Bells' Erect or spreading shrub with branches up to 1 m high, arising from stout root stock, mauve flowers.
Tall Shrubs / Small Trees (swamp) (no trees on landfill cap)
Acacia dealbata 'Si lver Wattle' Large shrub or medium‐sized tree with an erect main stem 6–15 m tall. Suitable to clay soils.
Acacia melanoxylon 'Blackwood' Medium-sized to tall tree. Suitable to clay soils.
Eucalyptus amygdalina ' Black Peppermint'
Tree to 30 m tall. Forming a l ignotuber. Bark rough on part or all of trunk and to base of large branches, finely fibrous
peppermint type, dark grey to grey-brown, smooth bark white to grey, or brownish, sometimes with ribbons of
decorticated bark in the upper branches. Suitable to clay soils.
Eucalyptus gunnii 'Cider Gum'
Small- to medium-sized evergreen tree. The bark is often persistent for several metres as a thin, grey stocking, or
shedding all over to leave a smooth, yellowish, patchy surface, weathering to white-, green- or pink-grey. Leaves are
stalked, ell iptical to ovate, to 8 cm long and 3 cm broad, concolorous, grey-green and thick. White flowers are produced
in midsummer. Grey / silver. Suitable to clay soils.
Eucalyptus obliqua ' Stringybark'
Tree to 90 m tall, or sometimes a mallee. Forming a l ignotuber. Bark rough to small branches or sometimes branches < 8
cm diameter smooth; rough bark stringy or fibrous, brown to grey-brown, longitudinally furrowed; smooth bark green or
grey. Suitable to clay soils.
Eucalyptus ovata ' Swamp Gum'Usually a medium-sized tree, but can grow up to 30 m tall. This tree is often found in swampy areas and in this
environment the tree is usually smaller in size. Suitable to clay soils.
Eucalytpus viminalis ' White Gum'Tree to 30 m high ; bark smooth or persistent on lower trunk, grey to grey-black, shortly fibrous, hard, platy, smooth
above, white, grey or yellow, shedding in long ribbons. Suitable to clay soils.
Melaleuca ericifolia 'Swamp Paperbark' Shrub or small tree to 8 m high with corky bark. Suitable to clay soils.
Melaleuca squarrosa Shrub or small tree to 12 m high with papery bark.
Nematolepis squamea 'Satinwood'Large shrub or small tree up to ~ 10m. The leaves are ell iptical , glossy green above and silvery below. Flowering
usually occurs in spring; flowers white. Suitable to clay soils.
Pomaderris apetala ' Dogwood'Widespread and abundant tree or large shrub species. One of the main components in the canopy of wet sclerophyll
forests. It has large leaves, which have irregular margins and irregularly lumpy surface. Suitable to clay soils.
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APPENDIX 10. Letters to Stakeholders
ATTACHED SEPARATELY
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APPENDIX 11. Certificate of Title
SEARCH DATE : 23-Jul-2014SEARCH TIME : 07.43 AM
DESCRIPTION OF LAND City of BURNIE Lot 1 on Plan 145841 Derivation : Part of 50000 acres granted to The Van Diemans Land Company Derived from A19301
SCHEDULE 1 BURNIE CITY COUNCIL
SCHEDULE 2 Reservations and conditions in the Crown Grant if any CONVEYANCE Made Subject to Exceptions And Reservations in favour of The V.D.L. Co.
UNREGISTERED DEALINGS AND NOTATIONS No unregistered dealings or other notations
SEARCH OF TORRENS TITLE
VOLUME
145841FOLIO
1
EDITION
1DATE OF ISSUE
22-Mar-2007
RESULT OF SEARCHRECORDER OF TITLES
Issued Pursuant to the Land Titles Act 1980
Department of Primary Industries, Parks, Water and Environment www.thelist.tas.gov.auPage 1 of 1
SEARCH DATE : 23-Jul-2014SEARCH TIME : 07.44 AM
DESCRIPTION OF LAND City of BURNIE Lot 2 on Sealed Plan 27996 Derivation : Part of Section 133, 50,000 Acres Granted to The Van Diemens Land Company Prior CT 4261/55
SCHEDULE 1 BURNIE CITY COUNCIL
SCHEDULE 2 Reservations and conditions in the Crown Grant if any SP 27996 EASEMENTS in Schedule of Easements CONVEYANCE Made Subject to Exceptions And Reservations in favour of The V.D.L. Co. created by a more fully set forth in Conveyance No. 14/322 14/322 CONVEYANCE Made Subject to Fencing Condition
UNREGISTERED DEALINGS AND NOTATIONS No unregistered dealings or other notations
SEARCH OF TORRENS TITLE
VOLUME
27996FOLIO
2
EDITION
1DATE OF ISSUE
16-May-1994
RESULT OF SEARCHRECORDER OF TITLES
Issued Pursuant to the Land Titles Act 1980
Department of Primary Industries, Parks, Water and Environment www.thelist.tas.gov.auPage 1 of 1
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APPENDIX 12. Chronology of the Waste Management Activities On Site
Stage 1 - Landfill Stages 1A, 1B and 1C were developed in the period from 1987 to 2004. The
Stage 1 landfill operations ceased in around 2004, with Stage 1A, 1B and 1C areas being
progressively capped between 2004 and 2005. A leachate rising main and second pump was
installed in late Feb 2009 to carry flows in excess of the main pump capacity (Pump 1) to the
Stage 2 Leachate Pond.
Stage 2 - Development of Stage 2A – Cell 1 and Cell 2 occurred in the period from 2004 to
2005. The life of Stage 2A was ~ 8.2 years, and was capped (interim cover) in March 2013.
Waste Facility - Construction of the Waste Transfer and Resource Recovery facility began in
April 2012 and was commissioned in Nov 2012. Pre-development it was the greenwaste
stockpile/chipping pad and runoff from the area went to stormwater to the west (minor) and
rest to the leachate pond from the eastern and southern areas.
A review of the BMWC landfill site was undertaken between 2006 and 2011, to assess the
long term needs of the Burnie Municipality, and the financial and environmental risks and
benefits of developing the remaining Stage 2B and Stage 2C areas. As a result of this review
it was proposed that a new Waste Transfer Station (WTS) be developed, and the Stage 2
landfill site would be closed and not further developed. Following the start of the WTS
operation in November 2012, the Stage 2A landfill site ceased to take waste. Since 2013 the
Stage 2A landfill Area has been capped with an interim final cover and is currently being
rehabilitated.
Pre 1987: Push pit
1987 to 2004: Development of Stages 1A, 1B and 1C
2004: Development of Stage 2A – Cell 1 and capping Stage 1B.
2005: Development of Stage 2A – Cell 2 and capping of Stage 1A & 1C.
2006: Development of Resource Recovery Area (Recycle Loop)
2012: Completion of Waste Transfer and Resource Recovery Facility and ceased
operation of Stage 2A landfill
2013: Interim cap of Stage 2A, rehabilitation.
2014: Initiation of Stage 1 leachate wetland treatment project
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APPENDIX 13. CFEV Assessment Component Report.
This document has been produced by The Department of Primary Industries, Parks, Water and Environment.
Questions concerning its content may be directed by email to [email protected]
The URL for this page is: http://wrt.tas.gov.au/wist/
Page 1 - CFEV Assessment Component Report
Important biophysical class (as predicted under pristine conditions) Biophysical Class Type: Tree assemblage Class Description: A mosaic of damp sclerophyll, wet eucalypt forest andrainforest extending from coastal north-western Tasmania, through Quamby to thenorth-eastern highlands in the north in the mid reaches of the Derwent and thelower Huon River in the south. Similar tree composition to assemblage 18. Species Composition: Acacia dealbata, Acacia melanoxylon, Allocasuarinalittoralis, Atherosperma moschatum, Banksia marginata, Bursaria spinosa,Eucalyptus amygdalina, Eucalyptus obliqua, Eucalyptus ovata Eucalyptus regnans,Eucalyptus viminalis, Exocarpos cupressiformis, Leptospermum lanigerum,Leptospermum scoparium var., Melaleuca squarrosa, Monotoca glauca, Notelaealigustrina, Nothofagus cunninghamii, Olearia argophylla, Phebalium squameum,Phyllocladus aspleniifolius, Pittosporum bicolor, Pomaderris apetala, Pomaderriselliptica, Pomaderris pilifera, Tasmannia lanceolata, Zieria arborescens Integrated Conservation Value Ranking: High Description: High Integrated Conservation Value (ICV). ICV integrates theRepresentative Conservation Value with known Special Values (eg. threatened andpriority species and communities, and priority sites). Special Values
River Report
ID: 179764
Easting: 405763
Northing: 5451938
Conservation Management Priority
Priority: Very High
Description: Very High Conservation Management Priority (CMP). The river sectionis part of a river cluster for which the conservation management is a very highpriority when development is proposed or occurs. This applies in the situationwhere further development occurs within the catchment which may contribute to achange in aquatic ecological condition or status. This CMP was derived byconsidering both its Integrated Conservation Value and land management security(by tenure).
Representative Conservation Value
Ranking: B
Description: B class Representative Conservation Value (RCV). This river sectionis within the second group of sites selected for rivers. Selection is based onrepresentativeness, rarity of classification units and naturalness.
This document has been produced by The Department of Primary Industries, Parks, Water and Environment.
Questions concerning its content may be directed by email to [email protected]
The URL for this page is: http://wrt.tas.gov.au/wist/
Page 2 - CFEV Assessment Component Report
Land Tenure Security Value: Low Description: This river section lies within a catchment that has predominantly lowsecurity of land tenure. There are no formal or mandatory restrictions in placeto ensure that the land within this catchment is managed to conserve or protectthe landscape from potential negative impacts. This includes areas of privateland, unallocated crown land, Commonwealth land, Hydro managed land and areasmanaged by other water authorities.
Name Scientific Name Type Status
burrowingcrayfish(Burnie)
Engaeusyabbimunna
ThreatenedFauna Species
Undifferentiated
platypus Ornithorynchusanatinus
Phylogenetically DistinctFauna Species
Non-outstanding
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APPENDIX 14. Risk Assessment Descriptors
Qualitative criteria for likelihood
Qualitative criteria for consequence
The level of risk caused by the previously identified hazard/hazardous events was determined
by combining likelihood and consequence in a matrix as presented below. Risk is calculated
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as the product of the likelihood of an event and the consequences of the event if it did occur:
RISK = LIKELIHOOD x CONSEQUENCE.
Risk matrix
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APPENDIX 15. Risk Assessment Evaluation
RISK EVALUATION 1 - discharge of raw leachate
Potential Impact
Hazard / Event Caused By Results In Likelihood Consequence Comments Risk MitigationResidual
Risk
RARE MODERATE LOW ▪ Continual monitoring of leachate levels in
select bores
LOW
Rising leachate levels within
landfill causing saturation and
weakening of containment bund.
Consequence: Consequences of potential impacts to receptors are considered to be moderate , as they are reversible, short to
medium term since only a portion of stored leachate would likely reach the unnamed tributary, and the capacity of the unnamed
tributry (from site boundary to Three Mile Rd) is and as a result of downstream dilution.
▪ Dilution of leachate will occur within the unnamed tributary from continuous groundwater discharge and surface runoff from
neighbouring properties. This creek is already degraded- water quality is relatively poor and the creek is eroded, with limited
riparian vegetation and weeds infestation. Consequently, discharge of leachate in the event of sliding failure of the landfill
embankment is unlikely to cause major additional degradation of the creek ecosystem and/or landscape values.
▪ Confluence of unnamed tributary into Cooee Creek is approximately 4km downstream of landfill. The 'unnamed creek' is one
of many tributaries with a catchment area of only 5.2 km2 (or 5% of the Cooee Creek catchment). Consequently, discharge of
leachate to the unnamed tributary is not expected to cause major impacts on Cooee Creek , key protected species (crayfish),
livestock or recreational users.
RARE MINOR LOW
Exposed solid waste and ponding of
raw leachate on site (impacts on on-
site workers). Potential mosquito risk.
RARE INSIGNIFICANT ▪ Only a very small number of council workers are present on-site. Risk management procedures already exist on site. LOW ▪ Existing risk management plan will be
updated to include responses to incidences
potentially connected with the treatment
system. This will include incidence
response for any on site ponding and
mosquito management. Appropriate training
of all on site personnel will be undertaken.
LOW
2 Raw leachate pump failure Power outage (weather, fire,
explosion etc)
Raw leachate overflow from pump
chamber and discharge into the
unnamed creek
UNLIKELY MINOR LOW ▪ Implement apprpriate equipment checks
and maintenance regimes.
LOW
Pump clogging due to lack of /
poor maintenance
Consequence: The consequence is considered to be minor as only a relatively small volume of raw leachate would potentially
reach the creek (most would likely infiltrate) . The flows that potentially do reach the creek would be further diluted which would
significantly reduce the severity of any environmental impact as discussed under Risk 1 above.
Ponding of raw leachate on site UNLIKELY INSIGNIFICANT As explained for Risk 1, only a very small number of Council workers are present on-site. Risk management procedures already
exist on site and these will be updated to reflect the risks associated with the leachate treatment wetland.
LOW LOW
1 Sliding failure of landfill
containment bund
leading to release of: 1) raw leachate
stored within the landfill cell, 2) raw
and partially treated leachate within
the wetland or 3) solid waste to
ajacent properties.
Wetland mass/location
compromises structural integrity
of landfill bund.
▪ Deterioration of creek water quality, major mass loads of pollutants, major sediment loads, altered creek hydrology.
POTENTIAL RISKS ASSOCIATED WITH THE RELEASE OF RAW LEACHATE AND/OR SOLID WASTE TO CREEK
▪ Negative health impacts on secondary recreational users of the Creek via high level of pathogenic microorganisms, elevated concentrations of metals and organic pollutants
▪ Potential risk of vectors (bird & mosquitoes) infecting livestock and humans with pathogens
Ecological
▪ General public
Human
LOW
Key receptors
▪ Unnamed tributary / Cooee Creek - water quality, ecosystem and landscape
values.
▪ Creek biota incl potential lsited species (Burnie Burrowing crayfish)
▪ Downstream creek water users (livestock, irrigation)
▪ Negative impacts on crayfish habitat in Cooee Creek as a result of poor WQ and increased sedimentation.
▪ Recreational users, irrigation users
▪ On site workers
▪ The Stage 1 landfill potentially has up to 100ML of stored leachate/groundwater below the cap while the wetland contains ~ 9ML
of partially treated leachate in total. In the event of landfill sliding failure, only the portion of raw and treated leachate contained
above the natural valley slope and subject to the lateral failure extent could be 'released' (assuming 1 ha of affected area this
would be ~0.5 ML of wetland partially treated leachate and ~5ML of stored raw leachate). The release will not be instantaneous
(it will be seep from the solid waste and clays) and will mainly be contained on site. Any seepage or leachate overflows will be
captured frst in the phytoremediation swale, which directs leachate in excess of the swale capacity to the emergency storage
where it can be pumped direct to sewer. Any flows not captured could discharge into the creek however there is significant
capacity (~2.5 ML storage from unnamed tributary to the Three Mile Rd culvert, Entura 2011), and there would be more than
sufficient time to temporarily dam this section of the creek and pump to waste.
Likelihood: It is assumed that issues with pump failure may occur from time to time due to power failure or inappropriate pump
maintenance, however there are sufficient contingencies in place to limit discharge to the creek. This includes a duty and standby
pump with generator back-up, gravity emergency storage system (6-10 hrs) which should enable adequate response time, and a
connection to sewer if this storage reaches capacity. A breach could only occur if the fleachate flow rates exceeded sewer
capacity (e.g. extreme rain events). Note, the proposed treatment system will not increase the inherent risk profile (will be reduced
due to gravitational emergency storage and sewer connection structures).
▪ Degradation of ecosystem and landscape values within the Unnamed Creek and/or Cooee Creek; erosion, weed infestation, .
▪ Potentially negative health impacts on livestock, poor WQ prohibits pasture irrigation
▪ Potential direct exposure of on-site workers to contaminants in exposed solid waste and/or raw leachate
▪ The site topography and available areas indicate that solid waste would be predominantly contained within the site. Given the
very localised nature of potential environmental impacts (immediate neighbouring properties only) the consequence was
considered to be minor.
Likelihood: Based on the Geotechnical Study , the likelihood of sliding failure of the landfill containment bund is very rare given
the Factor of Safety (FOS) for a non-leaking wetland is higher than 4, while the FOS for the present landfill containment bund is
assessed to be at least 4.5 (recommended FOS is 1.5). Based on the calculated FOS, placing the wetlands at least 10m from
the crest will not adversely impact on the stability of the containment bund wall.
Solid landfill waste spills to adjacent
propert/ies
Raw leachate discharging to the
unnamed tributary and possibly Cooee
Creek
Further erosion of landfill embankment
due to water spillages potentially
creating channels over embankment
BWMC Stage 1 Leachate Treatment System DPEMP November 2015 194
RISK EVALUATION 2 - discharge of partially treated leachate
Potential Impact
Hazard / Event Causes Result Likelihood Consequence Comments Risk MitigationResidual
Risk
1 Leakage of the wetland treatment
system
UNLIKELY MINOR Likelihood: It is considered unlikely that wetland seepage will not cause impacts given the following: LOW LOW
▪ Any localised seepage through the wetland liner and leachate migration through landfill would be retarded by the existing
underlying GCM or compacted clay liner.
Impairment of wetland performance due
to need for repairs.
▪ Wetland liners (GCL and HDPE) can accommodate large settlement. Liner (HDPE) accommodates a tensile strain of 1-10%,
hence can tolerate differential settlements of at least 450mm without breakage. Bunds have sufficient freeboard t accomodate
settlement.
Consequence: The consequence of any potential impacts are considered minor given the following:
▪ Seepage rate through compacted landfill clay cap is about 1% of typical daily flow rate from groundwater drainage system, so
additional flows due to seepage would be minimal . Due to these low flows, lateral seepage would be mostly contained on site
as a wet spot around the wetland. All ponded leachate would be partially treated further reducing the severity of any impacts to
on-site workers.
▪ System has a phytoremediation swale along the northern embankment which intercepts and treats seepage events if they
occur.
▪ Wetland cells can be individually isolated/bypassed for repair if required, without impacting performance of rest of wetland
▪ Any localised breakages in the wetland liner &/or bund settlements are easily repaired.
Likelihood: It is considered rare for this event to occur because settlement is unlikely to cause more than a localised effect and
because wetland volumes are small and if spill over the landfill banks will be contained within the phytoremediation swale and
emergency storage.
LOW ▪ Annual surveys of wetland bunds to track
changes.
LOW
Consequence: Considered to be minor since:
Ponding of the leachate on site,
potential direct exposure of on site
workers and potential mosquito issues.
▪ Released leachate will be partially (e.g. ammonia) or fully (metals and organics) treated for key pollutants.
▪ Spills will be intercepted by the phytoremediation swale along the northern embankment with excess captured within the
infiltration wetland.
▪ Treated leachate that does discharge into the unnamed tributary will be diluted as a result of continuous groundwater and
surface water discharge to creek.
▪ Any on site ponding of treated leachate will be localised, short term and appropriately managed under normal management
regimes on site. Given the relatively good quality of treated leachate , any direct exposure of on site workers is not expected to
cause any significant issues.
▪ Recreational users, irrigation users
b) Lateral seepage through the
wetland bund onto the clay capping.
▪ Creek biota incl potential lsited species (Burnie Burrowing crayfish)
2 Failure of wetland embankments Differential settlement of landfill
leading to localised subsidence
of wetland cell bunds and
overtopping of leachate.
▪ General public
▪ On site workers
Differential settlement of landfill
cap potentially impacting liner
integrity and/or overtopping from
wetland bunds. a) Seepage through the clay liner
base into the existing clay capping
POTENTIAL RISKS ASSOCIATED WITH THE RELEASE OF PARTIALLY AND/OR INADEQUATELY TREATED LEACHATE TO CREEK
Key receptors
▪ Unnamed tributary / Cooee Creek - water quality, ecosystem and landscape
values. ▪ Deterioration of creek water quality, increase in pollutants mass loading, sediment loads, altered creek hydrology.
Ecological
▪ Negative impacts on crayfish population in Cooee Creek as a result of poor WQ and increased sedimentation.
▪ Downstream creek water users (livestock, irrigation) ▪Impacts on the ecosystem and landscape values within the Unnamed Creek and/or Cooee Creek; erosion.
Human ▪ Potentially negative health impacts of minor WQ deterioration on livestock and pasture irrigation
▪ Potential risk of vectors (bird & mosquitoes) infecting livestock and humans with pathogens
▪ Potential direct exposure of on-site workers to contaminants in partially treated leachate
▪ Negative health impacts on secondary recreational users of the Creek via increased level of pathogenic microorganisms, elevated concentrations of metals and organic pollutants
Lateral seepage through landfill
containment bund resulting in
discharge of leachate to the
environment
▪ Existing risk management procedures will
be amended to include management of this
risk.
MINOR
▪ Only a small volume of leachate will potentially be discharged to the creek. Wetland volumetric capacity is approximately 9ML
, and in a case of embankment failure only a very small portion of this volume (depending on the scale of failure across the
system) will be released over the containment bund (likely <1 ML)
Partially treated leachate being
discharged directly over landfill
containment bund and disharging to
the creek.▪ Existing risk management plan will be
updated to include responses to incidences
potentially connected with the treatment
system. This will include incidence
response for any on site ponding and
mosquito management. Appropriate training
of all on site personnel will be undertaken.
RARE
BWMC Stage 1 Leachate Treatment System DPEMP November 2015 195
RISK EVALUATION 2 - discharge of partially treated leachate cont.
Potential Impact
Hazard / Event Causes Result Likelihood Consequence Comments Risk MitigationResidual
Risk
1. Not built to design Quality of the final effluent non-
compliant with set performance
targets.
POSSIBLE MODERATE ▪ Any deviation to design will be corrected before practical completion and commissioning of the system. MEDIUM LOW
Discharge of effluent of inadequate
quality to the creek.
Ponding of partially treated effluent on
site.
▪ Performance monitoring will be conducted
through the system to enable adaptive
response and to trigger emergency
recirculation or disposal to sewer
2. Cold weather (biological
performance compromised)
UNLIKELY MINOR ▪ System has been conservatively designed and modelled using site specific temperature data and conservative removal
coefficients for various pollutants. Many contingencies are included within the system design to accommodate reduced
performance without impacting on the quality of the final effluent.
LOW LOW
3. Change in leachate chemistry
beyond design ranges for
prolonged period of time
UNLIKELY MINOR ▪ Leachate is already in maturation phase so large fluctutaions extremely unlikely. Conservative wetland sizing has been
considered in the design.
▪ Wetland design is based on 5 years of site specific leachate quality data which shows stable conditions and on well
established leachate treatment wetland performance data (international literature).
LOW LOW
4. Contaminated via pesticides,
herbicides etc (weed
management - neighbouring
farms) that can cause
plant/microbial death, and
consequently reduced system
performance
UNLIKELY MINOR ▪ Wetlands are known to deal well with and degrade most of the currently used pesticides (Kadlec & Wallace, 2008).
Herbicide damage likely to be minor - wetland plants have high resilience and recover well from spray drift.
LOW LOW
5. Poor maintenance LIKELY MODERATE ▪ Wetlands are robust systems. Each wetland cells can be isolated/ bypassed for repair if needed, without impacting others. MEDIUM ▪ Appropriate maintenance budget will be
include in OPEX for the life of the wetland.
LOW
▪ Performance monitoring/maintenance
activities will be conducted through the
system to enable adaptive response and to
trigger emergency recirculation or disposal
to sewer.
▪ Appropriate training of staff responsible for
system maintenance will be undertaken,
including preparation of user-friendly
management and maintenance plans.
4 Extreme, prolonged rainfall
events
Discharge of inadequately treated
leachate to the Creek.
UNLIKELY MINOR Likelihood: It is considered unlikely that this event will occur and cause impact on key receptors given the following: LOW LOW
▪ Conservative sizing of system to accommodate the 90 percentile flows in the treatment process, ability to contain and enable
treatment via recirculation of up to 1500kL/day (20-year event peak flows), and ability to discharge to sewer.
▪ Project improves the current risk profile by separation of stormwater and leachate.
▪ Treatment system is operated on a maximum inflow rate ensurig consistency of treatment performance - flows in excess of this
are contained in the emergency overflow tank flow and in worst case discharged to sewer.
Consequence: Given all the safeguards in place, if this event does occur it would involve a discharge of only very small volumes
of partially treated leachate from the system. This is considered to potentially create only minor issues due to a major dilution
within the unnamed tributary (which would be especially high in those prolonged high rain event) and the fact that effects would
not be long term.
3 Failure or impeded performance
of wetland compromising the quality
of leachate outflow
▪ Recreational users, irrigation users
▪ Creek biota incl potential lsited species (Burnie Burrowing crayfish)
▪ General public
▪ On site workers
POTENTIAL RISKS ASSOCIATED WITH THE RELEASE OF PARTIALLY AND/OR INADEQUATELY TREATED LEACHATE TO CREEK
Key receptors
Volumes of groundwater-leachate
cannot be accommodated in the
collection/conveyance
network, or treatment system.
▪ Unnamed tributary / Cooee Creek - water quality, ecosystem and landscape
values. ▪ Deterioration of creek water quality, increase in pollutants mass loading, sediment loads, altered creek hydrology.
Ecological
▪ Negative impacts on crayfish population in Cooee Creek as a result of poor WQ and increased sedimentation.
▪ Downstream creek water users (livestock, irrigation) ▪Impacts on the ecosystem and landscape values within the Unnamed Creek and/or Cooee Creek; erosion.
Human ▪ Potentially negative health impacts of minor WQ deterioration on livestock and pasture irrigation
▪ Potential risk of vectors (bird & mosquitoes) infecting livestock and humans with pathogens
▪ Potential direct exposure of on-site workers to contaminants in partially treated leachate
▪ Negative health impacts on secondary recreational users of the Creek via increased level of pathogenic microorganisms, elevated concentrations of metals and organic pollutants
▪ The proposed system includes two safe guards to prevent discharge of inadequately treated final effluent: a) A recirculation line
that ensures non-compliant effluent is recycled through the treatment train before discharge; b) A contingency connection to
sewer.
▪ Design approach based on the sequential treatment train, multiple treatment cells, and conservative removal coefficients ensure
that any temporary failure of individual cells to perform properly will be compensated by the rest of the system without jeopardising
the overall system performance.
▪ Performance monitoring will be conducted
through the system to enable adaptive
response and to trigger emergency
recirculation or disposal to sewer
▪ Wetland designer will be retained during
construction / contract management
phases (e.g. superintendency) to ensure
that all system components and safeguard
management elements are constructed as
per design.
BWMC Stage 1 Leachate Treatment System DPEMP November 2015 196
RISK EVALUATION 2 - discharge of partially treated leachate cont.
Potential Impact
Hazard / Event Causes Result Likelihood Consequence Comments Risk MitigationResidual
Risk
5 RARE MINOR Likelihood: The hydrological study (Tasman Geotechnics Aug 2015) indicated that a rain event causing erosion and landslide
would be extremely rare (>1,000 years). While inappropriate irrigation activities could somewhat impact on this, the event would
still be classified as rare.
LOW LOW
Consequence: The consequence of this event is considered minor given the multiple contingencies in place and that this would
be localised to only a portion of the wetland system.
6 Vandalism 1. Exposed pipework connecting and
within wetland cells destroyed resulting
in leachate leakage.
UNLIKELY MINOR ▪ Most pipes will be buried and hence will not be damaged by fire. Exposed pipes if destroyed will not cause wetland operation to
cease. Any leakage (or any damage) can be easily and quickly localised and cells by passed. Site is fenced with access controls
in place to prevent unauthorside access.
LOW Unauthorised access control to wetland area LOW
Lightening 2. Plants burnt impacting system
performance.
POSSIBLE INSIGNIFICANT ▪ Most wetland plants are resistant to fire and will regrow rapidly after fire. Burning will not impact on the key removal
mechanisms by rhizosphere/soil microorganisms. Plant regrowth will enhance pollutant removal (a high rate of nutrient uptake
occurs after burning).
LOW Install lightening / short circuiting/ electrical
UNLIKELY MINOR ▪ Impervious HDPE liners will be buried and hence will not be exposed to above ground fire. LOW LOW
Fire within wetland system causing
physical damage to the system and
its components
▪ Recreational users, irrigation users
▪ Creek biota incl potential lsited species (Burnie Burrowing crayfish)
▪ General public
▪ On site workers
POTENTIAL RISKS ASSOCIATED WITH THE RELEASE OF PARTIALLY AND/OR INADEQUATELY TREATED LEACHATE TO CREEK
Key receptors
▪ Unnamed tributary / Cooee Creek - water quality, ecosystem and landscape
values. ▪ Deterioration of creek water quality, increase in pollutants mass loading, sediment loads, altered creek hydrology.
Ecological
▪ Negative impacts on crayfish population in Cooee Creek as a result of poor WQ and increased sedimentation.
▪ Downstream creek water users (livestock, irrigation) ▪Impacts on the ecosystem and landscape values within the Unnamed Creek and/or Cooee Creek; erosion.
Human ▪ Potentially negative health impacts of minor WQ deterioration on livestock and pasture irrigation
▪ Potential risk of vectors (bird & mosquitoes) infecting livestock and humans with pathogens
▪ Potential direct exposure of on-site workers to contaminants in partially treated leachate
▪ Negative health impacts on secondary recreational users of the Creek via increased level of pathogenic microorganisms, elevated concentrations of metals and organic pollutants
Flooding from adjacent property
upgradient (east) of landfill land and
material transport directly onto the
wetlands system.
Extreme weather and flooding
exacerbated by excessive
irrigation, soil creep, and farming
activities.
Physical damage of the treatment
system, compromised structures, and
reduced treatment performance
resulting in discharge of effluent of
inadequate quality.
BWMC Stage 1 Leachate Treatment System DPEMP November 2015 197
UNLIKELY INSIGNIFICANT It is considered unlikely that discharge of appropriately treated effluent from the treatment wetland will cause any significant
detrimental impacts on the receiving creek(s) and downstream users given the following:
LOW LOW
▪ Very high quality of treated effluent: Final effluent will be treated to a high standard prior to any discharge - water quality targets
for key contaminants of concern are in line with EPA Draft Water Quality Objectives for Cooee Creek and ANZECC (2000)
industry - short term irrigation and livestock drinking.
▪ Direct discharge of treated leachate (and mass loading to the creek) will be minimised through maximising on-site infiltration
within the last system’s cell (Cell 5 – Infiltration Wetland / Wet Forest). It is expected that most of the treated leachate ( 91% of
summer-autumn flows, and 78% of winter-spring flows) will discharge indirectly via subsurface infiltration to the Creek, utilising
land along the northern embankment within the landfill site boundary. Only during high rainfall events, flows in excess of the
infiltration capacity of the Infiltration Wetland would overflow directly to the Creek via a weir/cascade.
▪ Relatively poor condition of the unnamed tributary and Cooee Creek due to historic and current impacts from the landfill and
adjacent rural properties and residential developments. The unnamed tributary (for up to 3 km downstream of the landfill site) is
considered to be degraded, with relatively poor water quality and evidence of erosion, high weed extent, stock impacts and
limited riparian vegetation. In terms of water quality the Creek system is classed as ANZECC Ecosystem Condition 2: Slightly to
moderately disturbed systems and Ecosystem Condition 3: Highly disturbed system. based on the ANZECC (2000).
Consequently, discharge of highly treated effluent that is of much better quality than either of the creeks is unlikely to jeopardise
the quality of these surface waters. In terms of pollutant load, calculated annual loads of pollutants likely to be directly discharged
to the creek in storm events are relatively low - TSS<4 kg, TN, 17 kg, TP , 0.2 kg, Fe, 8 kg, Mn,5.4 kg. These mass loads are
considered small overall and lower than what probably occurs typically at the site, both as a result of discharges directly to the
Creek when flows exceed the 20 year ARI capacity of the pipe, pump and pit infrastructure, and also due to short duration storm
events which exceed the pump capacity and result in overflows from the MH1 chamber to the Creek. The potential impacts of
these pollutant loads are considered even less significant considering continual inputs from neighbouring properties.
▪ Discharge to the creek would help re-establish pre-development flows, since at present a substantial proportion of leachate
and groundwater (entrained within the leachate) flows is diverted to sewer. Hence, increasing the environmental flows, particularly
given climate predictions of declining rainfall, would be a beneficial outcome of the proposed treatment system.
▪ Unnamed creek is not used for recreation and this is unlikely to change in the future given declining water levels and many
alternative locations.
▪ Creek biota incl potential lsited species (Burnie Burrowing crayfish) ▪ Negative impacts on crayfish population in Cooee Creek as a result of lower WQ and increased sedimentation.
▪ Downstream creek water users (livestock, irrigation)
POTENTIAL RISKS ASSOCIATED WITH THE RELEASE OF FULLY TREATED LEACHATE TO THE CREEK
Key receptors
Ecological
▪ Unnamed tributary / Cooee Creek - water quality, ecosystem and landscape
values. ▪ Deterioration of creek water quality, increase in pollutant mass loadings, creek sedimentation , changes in creek hydrology.
▪ Degradation of ecosystem and landscape values within the Unnamed Creek and/or Cooee Creek; erosion, weed infestation, .
Discharge of treated effluent causing
1) degradation of the unnamed tributary
and Cooee Creek (WQ, ecosystem &
landscape values), and/or 2. negative
impacts on creek recreational users
and/or other downstream users
(irrigation, livestock drinking)
Human ▪ Potentially negative health impacts on livestock and negative impacts on pasture irrigation
▪ Recreational users, irrigation users ▪ Negative health impacts on secondary recreational users of the Creek via high level of pathogenic microorganisms, elevated concentrations of metals and organic pollutants
▪ General public ▪ Potential risk of vectors (bird & mosquitoes) infecting livestock and humans with pathogens
Discharge of treated effluent from the
on site treatment wetland compliant
with current discharge standards
(ANZECC etc)
▪ On site workers ▪ Potential direct exposure of on-site workers to treated leachate.