Revision Date issued Author(s) Reviewed by Approved by Date approved Revision type A 15/11/12 C Bailey D Smith M Yeates H Stevens D Smith D Smith 16/11/12 Draft B 16/11/12 C Bailey D Smith M Yeates H Stevens M Yeates D Smith 16/11/12 Draft C 19/11/12 C Bailey D Smith M Yeates H Stevens C Adnitt D Smith 19/11/12 Draft 0 21/11/12 C Bailey D Smith M Yeates H Stevens M Huber M Huber 21/11/12 Submitted to client for comment 1 17/12/12 C Bailey D Smith M Yeates H Stevens D Smith M Huber 19/12/12 Draft Final 1.1 21/01/13 C Bailey D Smith M Yeates H Stevens D Smith M Huber 21/01/13 Final submitted to the client 2 25/01/13 C Bailey D Smith M Yeates H Stevens K Goudkamp D Smith 29/01/13 Final submitted to the client 2.1 28/06/13 C Bailey D Smith M Yeates H Stevens M Huber M Yeates 28/06/13 Revised final 2.2 03/07/13 C Bailey D Smith M Yeates H Stevens M Yeates M Yeates 03/07/13 Revised final 2.3 10/07/13 C Bailey D Smith M Yeates H Stevens M Yeates M Yeates 10/07/13 Revised final 2.4 15/07/13 C Bailey D Smith M Yeates H Stevens M Yeates M Yeates 15/07/13 Revised final
Table 1. Summary of port-specific options for placement of dredge material on land. Disposal Option Port of Gladstone Rosslyn Bay State Boat Harbour Port of Hay Point Port of Abbot Point Port of Townsville Port of Cairns Offshore dredge material placement Placement of material on the seabed Y Y Y Y Y Y Land reclamation Creation of land in an area that is either permanently or partially submerged Y Mixture of clay, silt, sand, gravel N Y Rock only Y Sand Y Sand silt clay N Construction fill (supra tidal) Material used for fill purposes above the spring high tide mark for load bearing purposes Y Mixture of clay, silt, sand, gravel N Y Rock only Y Sand N Y Mine rehabilitation Material used to fill disused/ closed mines N N N N N N Shore protection/Erosion control Material used for engineered purposes of hard structures, seawalls N N N N N N Beach nourishment Material used for replenishing beaches that are prone to erosion N N N Y Sand N N Construction material Material used to produce fill material, construction product (e.g. brick) or mixture Y Gravel and sand N N Y Sand N N
Parks and Recreation Material used as fill for the parks and recreational purposes with minimal load bearing Y N N Y Sand N N Agriculture/Forestry/Aquaculture Material used as fertiliser for agriculture or forestry or to line ponds for aquaculture N N N N N N Habitat restoration Restoration or development of bird roost, nesting island, wetlands Y N N Y N N Landfill site capping Material used for capping or blending purposes as part of landfill management N N N N Y Clay N Permanent disposal in landfill Material taken to landfill site for permanent disposal N N N N N N Permanent disposal in confined disposal facility Permanent disposed of into constructed retention pond and not used further N N N N N N Y = Potential option for dredge material. N = Considered to not be a feasible potential option for dredge material.
use site. conveyor for transport from port On-road transport to final use site. destination. Port of Townsville Sailing and pumping dredge material to final disposal site. Pump dredge material to shore Access/loading/unloading De-watering Stabilisation Separation Water quality monitoring Infrastructure associated with reclamation site. N/A N/A N/A N/A N/A N/A Pump dredge material to shore Access/loading/ unloading De-watering Stabilisation Separation Water quality monitoring. Port of Cairns Sailing and pumping dredge material to final disposal site. NA Pump dredge material to shore Access/loading/unloading De-watering Stabilisation Separation Water quality monitoring On-road transport. N/A N/A N/A N/A N/A N/A N/A – not applicable, option is not considered feasible at this port. * Note that de-watering is assumed to occur at final destination within bund walls. **Further definition on the various types of re-use options can be found in the Beneficial Re-use Opportunities section of report.
Interior Bunds for construction of artificial wetland) 2005 AUD $2,000.00 Metre Kellogg Brown & Root Pty Ltd (2006) $2,352.0 Containment Dikes/De-watering Basins Construction Costs This report has assumed that de-watering costs provided in table 16 includes infrastructure costs for de-watering facilities (for example holding ponds). However, the report makes no attempt to provide indicative cost estimates to any degree of certainty. Therefore, for convenience, table 21 provides indicative costs for construction of containment dikes/de-watering basins. Derived estimates for an Australian context (AUD–2012) are based on the following assumptions: International prices have been converted to an indicative Australian cost based on relevant purchasing power parity indices and historical exchange rates for 1998 and 2007. The average exchange rate in 1998 was $0.60 USD/AUD (1 AUD = $0.60 USD). The average exchange rate in 2007 was $0.80 USD/AUD (1 AUD = $0.80 USD) The resulting costs estimates have been indexed to base year 2012 utilising the Australian producer price index for non-residential building construction. Table 21. Range of infrastructure costs. Type Price Year Currency Cost Unit Source AUD (2012) Containment Dike 1998 USD $91.00 to $228.00 $2.60 Ha m3 United States Environmental Protection Agency (2007) $752.50 to $1,885.30/ha $8.70/m3 De-watering basins construction 2007 USD $560,000 Based on construction of one facility (size unknown) Gannett Fleming (2008) $1,008,740.60 Elevated Conveyor Belt Construction Costs There are significant constraints for the transportation of dredged material by road transport from Abbot Point due to a wetland of national environmental significant behind the port. A possible solution (discussed at the Port of Abbot Point Risk Assessment Workshop, October 2012) could be to construct an elevated conveyor belt system across the wetland, this would enable the dredge material to be transported to a site without impacting on the wetland. Table 22 summarises potential cost estimates for various conveyor types based on the Abbot Point Development Area Multi-user Infrastructure Corridor Study (Queensland Government 2012). The cost estimates comprise the capital cost for conveyor (approximate), including mechanical, electrical, and structural works. 2012 estimates have been indexed by the Australian producer price index for non-residential building construction.
Morton, R. 2012, ‘Dudgeon Point Coal terminals project – dredged material re-use review’, Rick Morton Consulting Pty Ltd. Murray, L., 2008, ‘Dredge material as a resource’, Terra et Aqua 112, September 2008, PIANC. Nakamura, Y., no date, ‘Environmental restoration activities in Japan as the beneficial use of dredged material’, Port and Airport Research Institute, Japan. Nordstrom, K.F. 2005, ‘Beach nourishment and coastal habitats: research needs to improve compatibility’, Restoration Ecology 13,. 215-222. North Queensland Bulk Ports Corporation Limited 2011, Long Term Dredge Management Plan, Mackay Port 2012-2022, Author. Northern Bayshore Dredged Material Management Plan 2009, ’Identifying beneficial uses for dredged material’, Raritan and Sandy Hook Bays, Monmouth County, New Jersey, Monmouth County, New Jersey. NQBP, 2012, North Queensland Bulk Ports Limited, 2012, website information, . NSW Government 2011, ‘Ecosystem Restoration of Sydney Olympic Park’ Information sourced from website NSW Government 2012, ‘Tweed River Entrance Sand Bypassing Project’, Information sourced from website Olin-Estes, T.J., & Palermo, M.R. 2000, ‘Determining recovery potential of dredged material for beneficial use – Soil separation concepts’, in DOER Technical Notes Collection (ERDC TN-DOER-C13), U.S Army Engineer Research and Development Centre. Oxford Economics 2009, Valuing Effects of Great Barrier Reef Bleaching, Great Barrier Reef Foundation, Australia 2009. PIANC 2009, ‘Dredged material as a resource: options and constraints’, PIANC report no 104-2009. PIANC 2010, ‘Dredging and port construction around coral reefs’, Report no. 108 Environmental Commission. PIANC 2012, ‘Dredging 2012’, Technical session, San Diego 22-25 October Ports North 2012, Ports North website . Accessed November 2012. POTL, 2008, Port of Townsville Limited, website information, . Pro-dredging and Marine Consultants Pty Ltd 2012, ‘Improved Dredge Material Management for the Great Barrier Reef’, Letter to SKM, Pro Dredging and Marine Consultant Party Ltd, December 2012. Reserve Bank of Australia, 2012, Website information . Rogers, C. S 1990, ‘Responses of coral reefs and reef organisms to sedimentation’, Marine Ecology Progress Series 62, 185-202.
The World Association for Waterborne Transport Infrastructure (PIANC) reports: Murray, L. 2008, ‘Dredge material as a resource’, Terra et Aqua, 112, September 2008, PIANC. PIANC 2009, ’Dredge material as a resource: options and constraints’, PIANC report no 104-2009. PIANC 2010, ‘Dredging and port construction around coral reefs’, PIANC Report No. 108–2012, UNEP. PIANC 2012, ‘Dredging 2012’, Technical session, San Diego 22-25 October http://dredging12.pianc.us/agd_detailss.cfml?ssid=211.
OPTIONS Material Characteristics Grain size Geotechnical conditions Volume of material Chemical contamination and ASS LAND RECLAMATION (sub-tidal creation of land) Gravel, rock, sand or a mixture suitable for load bearing (construction). Clays and silts potentially suitable for creation of parks/recreation areas. Geotechnical characteristics must suit end use (e.g. load bearing). Direct function of area to be reclaimed. Depth of reclamation limited to ~1 m for silt/clay material due to drying time. Can accommodate contaminated material with treatment/capping/lining. ASS material requires management. CONSTRUCTION FILL (supra-tidal) Any material potentially suitable depending on end use. Silt and clays can take years to dry out and may need further treatment to quicken the process. Material needs to be dried to approximately per cent moisture content to enable re-handling with machinery. Geotechnical characteristics must suit end use (e.g. load bearing). Large areas of land are required for drying sites for silt/clay material. Only small volumes of dredge spoil can be dried, processed and transported at any one time due to land space availability and infrastructure required. Can accommodate contaminated material with treatment/capping/lining. ASS material requires management. MINE REHABILITATION Any material can be suitable. Silt and clays can take years to dry out and may need further treatment to quicken the process. Material needs to be dried to approximately per cent moisture content to enable re-handling with Material must be of geotechnical characteristics for end use e.g. engineering fill if roads are going to be built on land needs to have load bearing geotechnical properties. Large areas of land are required for drying sites to accommodate spoil. Only small volumes of dredge spoil can be dried, processed and transported at any one time due to land space availability Yes. Contaminated dredge spoil can be mixed with chemicals for binding purposes (e.g. ash) to form engineered fill with low permeability for use in strip mines. Treatment may be required for ASS's with lime to
machinery. and infrastructure required. de-neutralise. Material may need washing to remove salt content. SHORE PROTECTION/EROSION CONTROL Rock generally used for hard structures. Sand and gravel may be used behind the seawall to fill area. Material used must have high geotechnical properties, such as rock, to withstand coastal conditions and storm surge. Dependent on volume of material needed for project. Contaminated material may be used but will be capped and contained by other material to prevent leaching to surrounding marine environment. BEACH NOURISHMENT Sand and gravel grain size. Donor and recipient must be similar in nature. Sand content > 80 per cent. Sand content > 80 per cent. Volume of sand depends on size of beach and amount of sand required to inhibit future erosion. Sand must be clean and not contaminated. CONSTRUCTION MATERIAL Any material can be suitable dependent on product demand. Fine silts and clays have to be mixed with cement. Rock and sand is the most suitable material. Variety of materials can be used, however, geotechnical properties must be high. Materials may need to be mixed with additives to form suitable aggregate. Dependent on local demand for material and facilities where material will be processed and stored. Dredged rock is most suitable and is generally not contaminated. Contaminated material may need to be dewatered and washed prior to use. PARKS and RECREATION (fill Any material suitable however, sand and gravel most suitable Material must able to dry out within sufficient time frame. Only small volumes due to processing of material Low level contaminated soils preferable. Highly
Technical and Operational Feasibility Considerations Transport Draft of dredge and manoeuvrability Hydrodynamics of site (coastal conditions including currents and waves, storm surge etc) Operational risks LAND RECLAMATION (sub-tidal creation of land) Sand/silt/clay can often be pumped from dredging site to reclamation site. The practical limit for pumping spoil is 7-10 km. Greater distances require booster pumps. Pumping of coarser material including clay lumps may not be feasible. If pumping is not an option, multiple handling (loading/unloading of barges, trucking) may be required. Dredges/barges must be with suitable draft and manoeuvrability to be able to get close enough to reclamation site to pump or offload the material. Causeway/jetty construction may be required to offload if pumping not feasible. High energy conditions increase risks of pipe rupture, vessel grounding, and spills. Land reclamation site must not be in an area prone to coastal erosion or storm surge. Turbidity plumes, spills during pumping of spoil, failure of pipelines, vessel grounding/navigational hazards, failure of bund walls from extreme weather events. CONSTRUCTION FILL (supra-tidal) Sand/silt/clay can often be pumped from dredging site to reclamation site. The practical limit for pumping spoil is 7-10 km. Greater distances require booster pumps. Pumping of Dredges/barges must be with suitable draft and manoeuvrability to be able to get close enough to reclamation site to pump or offload the material. Coastal conditions can affect, delay and pose risk to unloading and/or pumping operations of material to shore and increase the risk of Turbidity plumes, spills and failure of drying pond walls. Groundwater contamination at capping site from chemical leachate. Transportation and facility or storage infrastructure
coarser material including clay lumps may not be feasible. Additional handling required to transport material from shore line to fill site. Causeway/jetty construction may be required to offload if pumping not feasible. spillage. failure, equipment breakdown. MINE REHABILITATION The material is pumped directly from the dredger as a slurry with water content around 90 per cent. The practical limit for pumping spoil is 7-10 km. Greater distances (> 10 km) may require the use of booster pumps. The dredge vessel must be with suitable draft and manoeuvrability to be able to get within close proximity to the drying sites or to berth facilities to pump the material. Shallow harbours create problems for vessels to approach site within suitable distances for pipelines and pumping equipment. Coastal conditions can affect, delay and pose risk to unloading and/or pumping operations of material to shore and increase the risk of spillage. Turbidity plumes, spills and failure of drying pond walls. Groundwater contamination at capping site from chemical leachate. Transportation and facility or storage infrastructure failure, equipment breakdown. SHORE PROTECTION/EROSION CONTROL Type of material will determine whether it needs to be pumped or unloaded from vessel to shore , or unloaded Dredge vessel must be chosen with suitable draft and manoeuvrability (many harbours very shallow and Coastal conditions may affect, delay and pose risk to unloading and/or pumping operations of material to Spills during works, turbidity plumes. Project not successful due to wave action removing deposited sediments.
at a berth facility directly into trucks. vessel cannot get close enough to site) to approach site within suitable distance for pipelines and pumping equipment, and/or offloading of material at berth/wharves to containment facilities. shore. Coastal conditions may influence net drift of sand deposited on beach and distribute it in other places. Depending on type of erosion control/shore protection being undertaken, project may simply be a one off beach fill or construction of embankments using hard material. BEACH NOURISHMENT Sandy sediments pumped are pumped either directly from dredger site while dredge is active or delivered to site by barge. If material may need to be double handled and pumped to shore then loaded onto trucks. Dredge vessel must be chosen with suitable draft and manoeuvrability (many harbours very shallow and vessel cannot get close enough to site) to approach site within suitable distance for pipelines and pumping equipment, and/or offloading of material at berth/wharves to Coastal conditions will affect, delay and pose risk to unloading and/or pumping operations of material to shore. Spills during works, turbidity plumes. Project not successful due to wave action removing deposited sediments.
pumped as a slurry mixed with water through floating pipelines from barge to facility. The practical limit for pumping spoil is 7-10 km. equipment, and/or offloading of material at berth/wharves to containment facilities. Material will need to be pumped from vessel to shore as per other options. Dredge vessel must be chosen with suitable draft and manoeuvrability (many harbours very shallow and vessel cannot get close enough to site) to approach site within suitable distance for pipelines and pumping equipment, and/or offloading of material at berth/wharves to containment facilities. Coastal conditions will affect, delay and pose risk to unloading and/or pumping operations of material to shore. Due to double handling of material, similar risks as other beneficial uses, such as spills, runoff and turbidity plumes. HABITAT RESTORATION/ CREATION Depending on type of material being used, it may require being pumped from vessel to drying ponds on shore. Direct Dredge vessel must be chosen with suitable draft and manoeuvrability (many harbours very shallow and Coastal conditions will affect, delay and pose risk to unloading and/or pumping operations of material to Spills during works, turbidity plumes. Project not successful due to wave action removing deposited sediments.
on Environmental Considerations Impacts on/risks to environmental values impacts Topography of area (i.e. slope/gradient and stability of disposal site) Carbon footprint Impacts on recreational and commercial users of the area LAND RECLAMATION (sub-tidal creation of land) Permanent loss of sub tidal habitat. Saline and turbid tail water discharge. Spills during filling operations. Alteration of bathymetry, coastline, coastal dynamics. Bund leakage/failure. Noise from vessels, pumps, heavy equipment. Low slope and stable site required for containment of material. Slopes < 2 per cent preferable. Slopes > 5 per cent unsuitable. Carbon emissions from material transport, pumping, construction emissions. Loss of land for recreation purposes, loss of coastal area, certain areas inaccessible to the public. Depending on end goal of land use, reclamation may create more usable space for recreation purposes. CONSTRUCTION FILL (supra-tidal) Long-term or permanent loss of habitat at drying sites. Saline and turbid tail water discharge. Spills during transport to drying site. Surface runoff and leaching after placement at disposal site. Aesthetic impact on surrounding environment from large drying sites and processing facilities. Noise, dust and water pollution. Other issues common to any construction fill project. Low slope and stable site required for containment of material. Slopes < 2 per cent preferable. Slopes > 5 per cent unsuitable. Carbon emissions from material transport, pumping, construction. Emissions increased by multiple handling and land transport of material. Permanent loss of land for drying sites.
habitat and nesting sites (e.g. turtles). shore. If material needs processing first (i.e. sand separation) then carbon emissions increased from processing facilities. with commercial and recreational boating activity. BEACH NOURISHMENT During project works: loss of marine plants, damage of sensitive aquatic and shoreline habitats, creation of turbidity plumes, sedimentation and beach compaction. Post project works if erosion is high sedimentation and turbidity can cause problems at adjacent habitats. Noise from pumping operations, gas emissions from vessels, turbidity plumes and spills. Preferable to use wave and tide action to distribute sediment along beach. High - if pumping of material is required, along with further processing at treatment facilities and potential transportation of material to site. Best scenario would be direct pumping of material to beach with no double handling. Beach not accessible during works in short term, vessel conflict with commercial and recreational boating activity. CONSTRUCTION Clearing of land for processing facilities Noise from pumping operations, gas Dependent on type of material used and form High - if pumping of material is required, Limits area available for
MATERIAL required within close proximity to dredge unloading berths. Large amounts of water required for processing of material. Cleaning of sands requires large discharge of water to surrounding environment and possible creation of plumes. Surface water contamination. Acquisition of land for processing facility and storage containments. Clearing of land for processing facilities and storage containments. emissions from vessels, turbidity plumes and spills. of aggregate. along with further processing/sand separation at treatment facilities and transportation of material to site. recreational use. PARKS and RECREATION (fill Surface water runoff may impact surrounding High pollution during project works due to Low slope and stable site required for High - if pumping of material is required, Creation of recreational land, positive impacts in
purposes) catchment during project works. Depending on level of contamination of material, leachate may enter surface waters or groundwater's. Erosion and sediment runoff during project works. machinery transporting material. Depending on material, site could be visually unappealing and smell while material is drying out. If land can be visually appealing in the long term. facilities and containment of material. Sloping land of < 2 per cent preferable. Slopes > 5 per cent unsuitable. Revegetation can help stabilise land. along with further processing at treatment facilities and potential transportation of material to site. Best scenario would be direct pumping of material to beach with no double handling. the long term. Clearing of land for drying sites (e.g. impact on turtle nesting sites, coastal vegetation), saline and turbid tail water discharge to surrounding coastal system, water quality impacts on surrounding creeks, large amount of water used in washing (if needed) and Noise and dust, machinery emissions from processing facilities. Stable site for depositing material. High carbon footprint due to pumping of material, construction drying ponds and processing facilities with high water usage, transportation facilities, trucks. High water use to remove salt content. Drying ponds and processing facilities not in close proximity to residential properties.
watchers, recreational fishers. LANDFILL(capping and blending for beneficial use) Clearing of land for drying sites (e.g. impact on turtle nesting sites, coastal vegetation), saline and turbid tail water discharge to surrounding coastal system from drying out ponds, water quality impacts on surrounding creeks, runoff, turbidity plumes and effluent spills during filling/pumping operations. Clearing of land for facilities and storage areas, storm water runoff from construction activities. Noise from pumping operations, construction activities, transportation and heavy machinery. Dust and surface water pollution. Aesthetic impact on surrounding environment from large drying out sites, processing facilities and landfill disposal sites. Low slope and stable site required for facilities and containment of material. Sloping land of < 2 per cent preferable. Slopes > 5 per cent unsuitable. High carbon footprint due to transportation of fill to landfill sites. Large amount of machinery involved with double handling of material. Loss of land for drying areas.
OPTIONS Planning Approval Considerations Legislation, planning and permits and approval Land availability Present and future land uses Proximity to residential and commercial properties LAND RECLAMATION (sub-tidal creation of land) Variety of approvals required (e.g. under Sustainable Planning Act, Fisheries Act, Coastal Protection and Management Act, Marine Parks Act, Environmental Protection Act, GBRMP Act, EPBC Act). Absolute constraints for land reclamation sites include significant wetlands, cultural heritage sites and protected areas. Suitable site in close proximity to dredge footprint must be available. Size of site directly determines the volume of spoil that can be accommodated. Example: 7500 ha required for 15 Mm3 volume of spoil at 1.5 m depth with a drying time of 8 months. Must be a need for reclamation for future use. General public not accepting of reclaimed land in close proximity to residential/recreational areas. CONSTRUCTION FILL (supra-tidal) Approvals required from various departments (e.g. under Environmental Protection Act). Absolute constraints for drying out (dewatering) facilities include significant wetlands, cultural heritage sites and protected areas. Large areas required for drying out material. Land has to be within reasonable distance to dredge site to allow pumping of material. Drying out areas preferably close to reuse fill sites. Use of land owned by port would be best case. Large areas must be available in vicinity of dredge site. There must be a need for the end product (fill material). General community not accepting of drying out areas close to residential centres.
MINE REHABILITATION Approvals required from various departments (e.g. under Environmental Protection Act). Absolute constraints for drying out (dewatering) facilities include significant wetlands, cultural heritage sites and protected areas. Large areas required for drying out material. Land has to be within reasonable distance to dredge site to allow pumping of material. Drying out areas preferably close to reuse fill sites. Use of land owned by port would be best case. Large areas must be available in vicinity of dredge site. There must be a need for the end product (fill material). Mines within reasonable distance requiring capping material or disused/abandoned mine lands or for acid drainage problems on mine sites. General community not accepting of drying out areas close to residential centres. SHORE PROTECTION/EROSION CONTROL Approvals required from various departments under Sustainable Planning Act, Coastal Protection and Management Act, Marine Parks Act, Fisheries Act etc. Beach /shore that requires erosion control. Positive impact on future use of beach/shore. Will affect local users during works. BEACH NOURISHMENT Many permits required to address all legislation triggered (e.g. EPBC Act, GBRMP Act, Coastal Protection and Management Act). Approval from various government departments Requires beach that has loss of sand due to littoral drift or other hydrodynamic factors. Beaches in close proximity to the project site must require nourishment and have similar sediment composition. Beach nourishment projects usually continuous (e.g. Gold Coast). Impacts on users of area during project works. Most beach nourishment projects undertaken in highly urbanised areas like the Gold Coast/Tweed Heads.
required CONSTRUCTION MATERIAL Various permits required, mainly for the dredging and treatment aspects. Suitable land needed for processing facilities. Clearing of land for site and facilities. Limits future use of site for other purposes. Site and facilities should be of sufficient distance from residential and commercial properties due to noise, visual and dust pollution PARKS and RECREATION (fill purposes) Variety of permits required - EPBC Act, Sustainable Planning Act, Coastal Protection Management Act, Aboriginal Heritage, State Development and Public Works Act. Local government approval also likely to be required. Suitable land required for drying of material. Beneficial in improving degraded land or creating land where there is lack of available space Land creation can add value to an area through parks/recreation opportunities. Variety of permits required - EPBC Act, Sustainable Planning Act, Coastal Protection Management Act, Aboriginal Heritage, State Development and Public Large areas required for drying out material. Land has to be within reasonable distance to dredge site to allow pumping of material. Drying out areas preferably Large areas must be available in vicinity of dredge site. There must be a need for the end product within the local industry (farming, aquaculture farms). Dewatering areas not close to residential properties
Works Act etc. close to reuse fill sites. Use of land owned by port would be best case. HABITAT RESTORATION/ CREATION Various permits required. Could be complex as near shore islands created within the World Heritage Area are unlikely to be approved. Approvals required from various departments and high levels of public interest in some locations from stakeholders Suitable land/water area that requires restoration. Land may be required for drying of material. Land acquisition for creation of habitat. Unlikely to be a need for the creation of near shore islands within the Great Barrier Reef World Heritage Area. Drying out ponds not in close proximity to residential properties. LANDFILL(capping and blending for beneficial use) Various permits required including land waste disposal permit. Suitable mine site within close proximity to project that requires fill for capping. Land acquisition required in close proximity to drying site or existing landfill sites with available space. Disposal sites may impact upon the future use of the land. Site not in close proximity to residential sites. LANDFILL permanent Various permits required including land waste disposal Available land required for drying areas and landfill sites Land acquisition required in close proximity to drying site Landfill sites within close proximity to residential areas
disposal) permit. Waste disposal fees and local government permits. (if can't use existing sites in surrounding area). or existing landfill sites with available space. Disposal sites may impact upon the future use of the land. would not be supported. NON-BENEFICIAL DISPOSAL (permanent disposal in constructed retention pond) Variety of approvals required (e.g. under Sustainable Planning Act, Fisheries Act, Coastal Protection and Management Act, Marine Parks Act, Environmental Protection Act, GBRMP Act, EPBC Act). Absolute constraints for construction of retention ponds include significant wetlands, cultural heritage sites and protected areas. Suitable site in close proximity to dredge footprint must be available. Size of site directly determines the volume of spoil that can be accommodated. Permanent impact on present and future land uses by construction of retention ponds. General public not accepting of construction of retention ponds in close proximity to residential/recreational areas.
OPTIONS Cost Considerations Construction costs Transportation costs On-going management costs LAND RECLAMATION (sub-tidal creation of land) Land acquisition, bund construction, walls, land pipelines and drainage systems and ponds for discharge of tail water, fencing, road access to reclamation ponds, chemical decontamination costs, berthing facilities (depending on dredger used). Dredge/barge/pumping costs. Handling and trucking costs if material not pumped, potentially causeway/jetty costs for unloading. Security, fence maintenance, long-term alienation of site (drying of material can take years), potentially ongoing contamination/ASS management, environmental monitoring. CONSTRUCTION FILL (supra-tidal) Drying ponds, bund walls, fencing, pipelines and pumping equipment, drainage systems and discharge ponds at drying site. Storage facilities and machinery for loading of material, road and/or rail infrastructure for access to site, machinery and unloading equipment, storage facilities at offloading site (e.g. additional infrastructure at site for unloading material). High transportation costs due to distance to mine site. Cost for dredge vessels and/or barges to transport material to drying site. Loading and unloading machinery, trucks/train for transporting fill, machinery for unloading equipment at fill site. Maintenance of drying sites, infrastructure for processing storing and transporting fill. MINE REHABILITATION Drying ponds, bund walls, fencing, pipelines and pumping equipment, drainage systems and discharge ponds at drying site. Storage facilities and machinery for loading of material, road High transportation costs due to distance to mine site. Cost for dredge vessels and/or barges to transport material to drying site. Loading and unloading machinery, trucks/train for transporting fill, Maintenance of drying sites facilities, infrastructure for processing storing and transporting fill.
OPTIONS ABSOLUTE Grain size of material and chemical contamination Land availability and Topography Environmental Impacts Material handling and infrastructure Port of Gladstone LAND RECLAMATION (sub-tidal creation of land) Maintenance dredged sediments are predominantly coarse with 54 per cent of all locations having a combined gravel and sand proportion of > 90 per cent (WBM 2012). Sediments within shallower intertidal areas are characterised by silts and clays. Capital dredged sediments are lensed consisting of fine silts, sands, gravels to stiff clays (GPC pers.comm. 2012).Sediments within Gladstone harbour are clean and uncontaminated. There are some Potential Acid Sulfate Soils in near shore environments. Possible treatment may be required. Land availability is highly constrained due industrial development. In the Western Basin there is already a large reclamation area of 408.5 ha for the disposal of approximately 55 Mm3 of spoil. There are other possible sites on Curtis Island at Hamilton Point and Laird Point, however, due to the growth of Gladstone these sites are under investigation by future LNG proponents. The harbour has high environmental values and on the eastern and western areas have significant seagrass meadows, fringing mangroves and intertidal habitats. Areas further north of the present reclamation area have no access (road) and have high environmental values. There may be possible areas south at South Trees towards Boyne Island and Tannum Sands, however, access any be difficult due to narrow channels. There was a small area to the east (contaminated bunded site) that could be considered for reclamation. Tidal lands in the vicinity of Gladstone harbour are generally comprised of either seagrass, fish habitat areas or mangrove habitat and the entire harbour is a dugong protection zone. Impacts relating to water quality associated with de watering would need to be mitigated against. Gladstone is an industrial city and handling facilities and infrastructure are not constraints CONSTRUCTION Sediments may be suitable for To use the material as construction fill, the Significant impacts on Gladstone is an industrial city
FILL (supra-tidal) construction purposes due to high sand and gravel content, however they would need to be separated. material would first need to be dewatered and treated prior to use for fill. This would require a large area of land for drying ponds. As Gladstone is highly undulating, the flat areas are within the near shore environment. The majority of land in Gladstone is already owned for industrial purposes. The remaining areas have high value mangrove and wetland habitat. Land availability is a constraint. terrestrial environmental values to clear sufficient land to dry material prior to dredging would be a constraint. Ongoing discharges of waste water during works as part of the de watering process. and handling facilities and infrastructure are not constraints MINE REHABILITATION The nature of the material at Gladstone being dominated by coarse grains, the material may be suitable for mine capping as engineered fill. The material may be suitable for rehabilitation of mine site (revegetation), however, the high salt content may be an issue. Gladstone is highly industrialised and land is of prime importance for a growing mining industry. To use the material for mine capping purposes, the material would first need to be dewatered and treated prior to use for fill. This would require a large area of land for drying ponds. There may be possible areas in the southern area of the harbour of Boyne Island and Tannum Sands and mine sites of Boyne Island may require capping material. The benefits of developing a large drying area for the processing of material and subsequent loss of near shore habitat would have to outweigh the impact on environmental values. Significant impacts on terrestrial or wetland environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water during works as part of the de watering process. Positive environmental impacts may be revegetation of mine site for future land use, however, the material may need high processing and treatment to enable it suitable for revegetation purposes. The benefits of revegetation of the No de-watering and drying facilities in place currently. Transport of dried material, once created would be difficult by road, would involve large amounts of rehandling and truck movements.
fractions. material is a constraint. prior to dredging. Ongoing discharges of waste water during works as part of the de process. constraints PARKS and RECREATION (fill purposes) The material may be suitable for parks and recreational purposes, but would need to be dried out first. Due to the high plasticity, material is unlikely to be able to support significant infrastructure. Capital dredging material may be more suitable for parks/recreation purposes due to higher sand content than maintenance dredge material. To use the material as foundations, the material would first need to be dried out. Land availability is a constraint. Significant impacts on terrestrial or wetland environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water during works as part of the de process. Gladstone is an industrial city and handling facilities and infrastructure are not constraints The material is not suitable due to the high salt content. No agricultural areas have been identified as requiring a need for this use. Significant impacts on terrestrial or wetland environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water during works as part of the de watering process. The material would need dewatering, processing and potential treatment of reduce salt content. Large facility required and machinery for loading and unloading of material at farm gate. Limited demand likely to be present for product.
purposes and there are no de-watering and drying facilities currently in place. prior to dredging. Ongoing discharges of waste water during works as part of the de watering process. LANDFILL permanent disposal) The material is suitable for disposal Land availability is a major constraint for this use. Significant impacts on terrestrial or wetland environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water during works as part of the de watering process. Terrestrial land lost to non-beneficial land fill use, therefore, deeming it unavailable in the future for other purposes. There are facilities in place to construct bunds and transport the material to shore. This is not a constraint. NON-BENEFICIAL DISPOSAL (permanent disposal in constructed The material is suitable for disposal but needs to be dried out first before it can be transported to landfill. Land availability is a major constraint for this use. Significant impacts on terrestrial or wetland environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water There are facilities in place to construct drying out ponds and transport the material to site once it is dried either by truck or by train. This is not a
retention pond) during works as part of the de watering process. Terrestrial land lost to non-beneficial land fill use, therefore, deeming it unavailable in the future for other purposes. constraint. Rosslyn Bay Boat Harbour LAND RECLAMATION (sub-tidal creation of land) Sediments would be suitable for use as reclamation fill, although the structural properties of sediments would need further investigation if the land was to be developed. Capital dredging sediments were used in construction of the harbour. Sediments from ongoing maintenance dredging are of a finer grain size, due to settlement of suspended sediments from the water column. Sediments generally uncontaminated with a small amount potential requiring treatment for ASS. Highly constrained as lands immediately surrounding the harbour have a diversity of uses, from National Park, farm land, park land and residential. The only viable location potentially suitable for reclamation would be an extension of the existing reclaimed parkland, by extending it to the north and west. Topography of areas surrounding the harbour are undulating and not suitable for reclamation. Extending the existing reclamation area would result in impacts upon a narrow fringe of mangroves, direct disturbance to soft bottom habitats. Waste water discharges during construction would increase turbidity, which may have impacts on coral reef communities at the nearby Bluff Rock and Wreck Point. Only available area is extension of existing reclamation area. This would impact local residents and not possible due to future proposed uses of park area (developments). CONSTRUCTION Sediments derived from capital dredging projects are likely to have Highly constrained as lands immediately surrounding the harbour have a diversity of While the reuse of dredge spoil for construction No existing dewatering, drying or storage areas for treatment
could generally be managed during construction. Environmental benefits would need to be high to outweigh impacts (e.g. provide habitat for threatened species). No guarantee of successful use by birds. LANDFILL (capping and blending for beneficial use) Sediments are of a suitable grain size and quality for capping purposes. Non contaminated and suitable for in landfill capping. Highly constrained due to lack of available areas for drying sites. Sediments would first need to be dewatered and dried somewhere close to the harbour. The only flat land where this could happen is a salt marsh/clay pan environment 2 km to the south of the harbour, which has high environmental values. Pumping of material across the salt marsh, loss of habitat, displacement of species, smothering of benthic habitat. Upgrade of local roads would also be required and may impact on terrestrial environmental values if clearing was No existing dewatering, drying or storage areas for treatment of dredged material. Loading and unloading facilities at drying site and landfill site. Local roads would need upgrading to handle high loads of heavy vehicles.
at Tug Harbour. MINE REHABILITATION Clays and silts need to de-watered. The material would not be suitable as capping fill for engineered purposes (load bearing) due to the high silt content and may require washing to remove salt. The material is not contaminated and would not need further processing other than some liming to reduce minor ASS levels as determined by testing. Drying ponds required for dewatering of material. Land availability in Hay Point and Dudgeon Point is highly constrained due to environmental values and existing or proposed uses. Only small sections of flat land are available, but these are too small to accommodate the volumes of material required. Significant impacts on terrestrial environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water during works as part of the de watering process. No facilities in place currently. Drying areas and associated facilities would need to be constructed. Transport of dried material, once created may be by road or rail and would involve large amounts of rehandling and truck movements. It is not technically feasible to pump the dredge material 12-14 km to shore. SHORE CONTROL Only the rock component of dredge material has the potential to be suitable, however, the rock is weathered and does not meet appropriate engineering standards. Sands, silts and clays unsuitable. Given the likely small quantities of rock, land availability may not be a large constraint. Local need for shore protection structures would also be required, such as the Tug Harbour expansion. Generally environmental impacts will be manageable, depending on the location of works. Design would need to minimise impacts on long shore sand migration, turtle nesting beaches and marine plants. Limited infrastructure currently available. Would depend on volumes of rock produced and their need in local projects. Rock material unloaded directly from vessel to shore best scenario. Transport of rocks by road or rail possible in small quantities. BEACH Material not suitable due to high silt Local beaches tend to have relatively high environmental values and may not require Use of silts and clays will negatively impact beach N/A
NOURISHMENT and clay content. nourishing with additional sand. Material not suitable and would cause negative impacts on beaches. amenity. Material not suitable. CONSTRUCTION MATERIAL Material with high sand content most suitable. Dredged rock is not suitable as construction material as too weathered. Previous studies have found other material (clay, silts and sands) not suitable for construction fill purposes. Rock material will not require any treatment. Land highly constrained due to environmental values and surrounding residential / commercial use. May be existing available areas for storage of rock material Tug Harbour. Land needs to have low slope and stable topography. Clearing of land for unloading and loading facilities may displace species from area. Use of areas within Tug Harbour most suitable. It is not technically feasible to pump the dredge material km to shore (Pronk 2012). PARKS and RECREATION The material may be suitable for parks and recreational purposes, but would need to be dried out first. Its salt content may limit its use as material for revegetation purposes. The material is not contaminated and would not need further processing other than some liming to reduce minor ASS levels as determined by testing. Flat land required for drying areas. Most of the land at Hay Point and Dudgeon Point is constrained due to environmental values and existing or proposed uses. Significant impacts on terrestrial environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water during works as part of the de watering process. No facilities in place currently. Drying areas, loading and unloading machinery, road access required. Large amounts of rehandling and truck movements. It is not technically feasible to pump the dredge material 12-14 km to shore (Pronk 2012). The material is not suitable due to its salt content. Mackay region Drying ponds required. Most of the land at Hay Point and Dudgeon Point is constrained Significant impacts on terrestrial environmental The potential to use dredged materials from marine areas
generally has relatively high value agricultural soils, of a better quality than dredged material (lack of demand for material). The material would require a significant reduction in its salt content for use in agricultural applications. due to environmental values and existing or proposed uses. values to clear sufficient land to dry material. Ongoing discharges of waste water during works as part of the de watering process. Environmental values of surrounding areas would be impacted (wetlands, creek systems). High use of water for processing / washing material. for agricultural purposes is extremely limited as the material is generally fine grained and saline. Experiments conducted by the Port of Brisbane indicate that silty clays because of their fine-grained nature easily form a crust when drying that repels water. Blending organic matter into the material (e.g. compost) can reduce such issues but there are major logistical in blending the dredge material (Rick Morton Consulting 2012). No facilities in place currently. Transport of dried material, once created would be difficult by road, would involve large amounts of rehandling and truck movements. Does not appear to be agricultural land in the area requiring clean fill. HABITAT RESTORATION/ The material is suitable for the construction of artificial wetlands or There are no significantly degraded habitats within the Hay Point area that require Change in natural habitat types within the Great Barrier It is not technically feasible to pump the dredge material
Involves large amounts of rehandling and truck movements. NON-BENEFICIAL DISPOSAL (permanent disposal in constructed retention pond) Material suitable for permanent disposal. May need ASS treatment. Large areas of flat land highly constrained. High due to loss of habitat. Permanent loss of area, no future use for land. It is not technically feasible to pump the dredge material km to shore. Construction of ponds, facilities and road access required. Port of Abbot Point RECLAMATION (sub-tidal creation of land) Sediments of Abbot Point are generally composed of fine to medium sands with varying degrees of silt and some clay. Material with a high content of sand may be suitable for reclamation. Sediments are uncontaminated and generally have a low acid potential, which can be managed through treatment or remaining saturated as required. There are some areas available for reclamation within pumping distance of dredging areas. Available land is quite undulating. Flat land tends to have high environmental values (wetlands and dune vegetation). There is an area to the left of the trestle that has been previously identified for land reclamation for a multi cargo facility (MCF). Apart from the MCF area, other areas within the port are highly constrained due to high conservation value (beaches, Sandy beaches are present on the eastern side of Abbot Point. The sandy nature of sediments would mean that water quality impacts of reclamation could be managed, provided silt and clay content was relatively low. Loss of intertidal and sub tidal habitat. Some temporary impacts to local water quality conditions and possibly Sediments could be pumped from dredge to reclamation area. Dewatering would be required within the reclamation area, with discharge of waste water.
water and groundwater. SHORE CONTROL Dredged material likely to be largely devoid of rock material (minimal supply). Rock material (if found) would need to meet engineering guidelines for use. Beaches requiring erosion control are not known to be present in the area. Generally environmental impacts will be manageable, depending on the location of works. Design would need to minimise impacts on long shore sand migration, turtle nesting beaches and marine plants. If rock is found, existing handling areas may be able to be used for loading and unloading of material. Road access required for transport of rock to site. BEACH NOURISHMENT Sediments of Abbot Point are predominantly fine to medium sands, comprising 50 per cent sand with increasing silt content with depth. Some clay also in deeper areas. Such material is likely to be of some value for beach nourishment. The material is uncontaminated and may not require treatment for ASS if sediment kept underwater. There are no known beaches in the area requiring beach nourishment works. If appropriate grain sizes are used (where available), impacts will be minimal. Sediments with a high silt and/or clay content must be avoided or environmental impacts will be high and changes to natural environmental qualities may result. Beaches have high conservation value for nesting turtles and other marine species, unlikely that beach nourishment will be supported. Depending on material, may be able to pump directly from vessel to beach site. If double handling required and sand needs to be separated from clays, then drying ponds and facilities will be required. Loading and unloading machinery for transportation.
CONSTRUCTION MATERIAL Surface sandy sediments may have some value as a construction material (most likely low grade, due to the fine to medium grain size). Sediments with high silt content would not be suitable. May only be feasible for a relatively a small portion of the dredged material. No known industries locally that would require sandy material with some silt content. General lack of available land to store large amounts of material on. A variety of beach topographies can be addressed through appropriate engineering. Sediments would need to be dewatered first, with little flat spare land available. Minimal, although sediments must first be dewatered, which would result in significant impacts to terrestrial ecology due to lack of suitable land and clearing required/impacts on sensitive wetlands. Dependent upon volumes involved. Lack of general facilities to dewater and store clean sands. PARKS and RECREATION The material may be suitable for parks and recreational purposes, but would need to be dried out first. The material is not contaminated and would not need further processing other than some liming to reduce minor ASS levels as determined by testing. Salt content may pose problems for use in revegetation. Drying ponds required. Most of the land at Abbot Point is constrained due to environmental values and existing or proposed uses. Sediments would need to be dewatered first, with little flat spare land available. Significant impacts on terrestrial environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water during works as part of the de watering process. No facilities in place currently. Transport of dried material, once created would be difficult by road, would involve large amounts of rehandling and truck movements. Does not appear to be spare recreational land in the area requiring clean fill. The material is not suitable due to its salt content. Bowen region generally has agricultural soils of a better quality than dredged material (lack of demand for material). The material would require a significant reduction in its salt content for use Drying ponds required. Most of the land at Abbot Point is constrained due to environmental values and existing or proposed uses. Significant impacts on terrestrial environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water during works as part of the de No facilities in place currently. Transport of dried material, once created would be difficult by road, would involve large amounts of rehandling and truck movements. Does not appear to be agricultural land
in agricultural applications. watering process. in the area requiring clean fill. HABITAT RESTORATION and DEVELOPMENT The material is suitable for the construction of artificial wetlands or bird roost sites. Some wetlands close to Abbot Point may benefit from restoration (e.g. Caley Valley Wetland). For migratory waders, construction of suitable roosting sites needs to be aligned with the existence of high value feeding sites. No guarantee that site would be used and have ongoing environmental value. Sediments would need to be dewatered first, with little flat spare land available. Risk of environmental impacts on existing wetland values. Change in natural habitat types within the Great Barrier Reef World Heritage Area. Impacts are depended upon location and could generally be managed during construction. Environmental benefits would need to be high to outweigh impacts (e.g. provide habitat for threatened species) Transport of sediments to the wetland and dewatering to the required standard would be the biggest logistical constraint. LANDFILL (capping and blending for beneficial use) Material will need to be dewatered prior to transport. High salt content may present problems at mine or land fill site. Sediments are uncontaminated and generally have a low acid potential, which can be managed through treatment. Drying ponds required. Most of the land at Abbot Point is constrained due to environmental values and existing or proposed uses. Only small sections of flat land are available, but these are too small to accommodate large volumes of dredged material. Available land is quite undulating. Flat land tends to have high environmental values (wetlands and dune vegetation). Existing landfill sites required that need Areas most suited to construction of storage and dewatering facilities are of high environmental values (e.g. Clare Valley Wetland). Impacts on terrestrial ecology. Existing, developed, flat land is at a premium and unlikely to be of sufficient size to accommodate treatment, dewatering and storage prior to transporting away. Loading and unloading facilities required for transportation of material to landfill site.
reliant on tourism. Transport of dried material to mine sites may also be problematic due to the mountainous terrain of the wet tropics surrounding the port. Drying times in the wet tropics would also be highly constrained and larger areas would therefore be required. SHORE CONTROL No rock material is present in the areas required for maintenance dredging. The presence of rock in deeper sediments requiring capital dredging is unknown and worth further investigation. The northern beaches may require shore protection, but mainly from sand nourishment. No rock material is present in dredge sediment. Generally environmental impacts will be manageable, depending on the location of works. Design would need to minimise impacts on long shore sand migration, turtle nesting beaches and marine plants. Limited infrastructure currently available. Would depend on volumes of rock produced and their need in local projects. Transport of rocks by barge, or road may be possible. Loading and unloading facility or machinery required. BEACH NOURISHMENT Sediments dredged are unsuitable for beach nourishment purposes due to the high silt and clay content. The northern beaches are a considerable distance from the port and too far to pump directly from footprint to site. There may be smothering of benthic habitats in the short term. Silts and clays must be avoided or impacts will be high. The material would require separation of clean sand, then could either be transport by vessel and pumped to the beach or transported by truck. CONSTRUCTION Maintenance dredging material is unsuitable, due to the fine grain size of sediments (clays and silts). Clean sands are required for use as Dredged material would first need to be dewatered and treated prior to use as construction material. Most land in the vicinity of the port is used for high density Minimal, although sediments must first be dewatered, which would result in significant impacts to Material would need massive processing and addition of aggregates. Large rehandling facilities required and transport
construction material. Capital dredging material may need further investigation for this purpose if the sand content is high. residential purposes, conservation and cultural heritage management, forestry purposes or mixed agricultural purposes. Accordingly, establishment of a spoil processing area is highly constrained due to a lack of available land and a growing city, reliant on tourism. Drying times in the wet tropics would also be highly constrained and larger areas would therefore be required. terrestrial ecology due to lack of suitable land and clearing required. High use of water and discharge of waste water is sands needs to be washed. equipment. PARKS and RECREATION The material may be suitable for parks and recreational purposes, but would need to be dried out first. Due to the high plasticity, material is unlikely to be able to support significant infrastructure. Dredged material would first need to be dewatered and treated prior to use as fill in parks and recreational facilities. There may be the opportunity to use the material for the new upgrade/redevelopment of the Cairns Esplanade for landscaping purposes, however, the constraint is finding a suitable area for the drying out of the material. Most land in the vicinity of the port is used for high density residential purposes, conservation and cultural heritage management, forestry purposes or mixed agricultural purposes. Drying times in the wet tropics would also be highly constrained and larger areas would therefore be required. Significant impacts on terrestrial environmental values to clear sufficient land to dry (and treat if needed) the material . Ongoing discharges of waste water during works as part of the de watering process. The material would need dewatering, processing and potential treatment of reduce salt content. Large facility required and machinery for loading and unloading of material at recreation site. The material is not suitable due to Dredged material would first need to be Significant impacts on No facilities in place currently.
its salt content. Cairns region generally has relatively high value agricultural soils, of a better quality than dredged material (lack of demand for material). dewatered and treated prior to use as fill for agricultural purposes. Most land in the vicinity of the port is used for high density residential purposes, conservation and cultural heritage management, forestry purposes or mixed agricultural purposes. Accordingly, establishment of a spoil processing area is highly constrained due to a lack of available land and a growing city, reliant on tourism. Drying times in the wet tropics would also be highly constrained and larger areas would therefore be required. terrestrial environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water during works as part of the de watering process. Transport of dried material, once created would be difficult by road, would involve large amounts of rehandling and truck movements. There is not a demand for the product. Infrastructure may be required at the farm gate to blend dredged material with in situ soils. HABITAT RESTORATION/ CREATION The potential for ASS present and the high plasticity clay content it is unlikely that the dredged material would make a suitable vegetation growth medium (Golder Associates 2012) There is an area east of Trinity Inlet that is being rehabilitated to restore tidal water habitat. Lime flushing has been undertaken to remove the ASS present. This could be a potential site to use dredge material for further habitat restoration, however, the ASS potential of the dredged material would need to be addressed.. Potential for ASS to be present and the wetland have already been rehabilitated so could be more sensitive to impacts from ASS. Removing the bunds could cause a land to subside. Material would need to be pumped to restoration/development site using floating pipelines via the Trinity Inlet which may pose short term navigational issues but not a major constraint. LANDFILL(capping and blending for beneficial use) Due to the fine mud and silt content the dredged material would not be suitable for capping of landfill sites. Potential for ASS to be present Springmount waste management (landfill) facility near Mareeba has 140 ha of land. However Mareeba is approximately 40 km west of Cairns. There is also Yungaburra waste management facility approximately 40 The potential for ASS would need to be treated to prevent any adverse impacts. No facilities in place currently. Dewatering, processing and material handling faculties (loading and unloading at either end) would be required.
km south-west of Cairns. The dredge material would also need to be dried out first which poses a constraint as no land has been identified for this. The nearest landfill site is 40 km west of Cairns through mountainous terrain. Transport of dried material, once created would be difficult by road, and would involve large amounts of rehandling and truck movements. LANDFILL permanent disposal) prior to landfill. The material is suitable for disposal but needs to be dried out first before it can be transported to landfill. Springmount waste management (landfill) facility near Mareeba has 140 ha of land. However Mareeba is approximately 40 km west of Cairns. There is also Yungaburra waste management facility approximately 40 km south-west of Cairns. The material would need to be dried out before transporting. There is no land available for this purpose. Flat land near the port is used for residential, tourism, cultural, conservation or agricultural purposes. Land disposal sites (and existing landfill sites) are scarce in Cairns due to competing needs for land from a developing coastal city. Significant impacts on terrestrial environmental values to clear sufficient land to dry material prior to dredging. Ongoing discharges of waste water during works as part of the de watering process. Terrestrial land lost to non-beneficial land fill use, therefore, deeming it unavailable in the future for other purposes. No facilities in place currently. Dewatering, processing and material handling faculties (loading and unloading at either end) would be required. The nearest landfill site is 40 km west of Cairns through mountainous terrain. Transport of dried material, once created would be difficult by road, and would involve large amounts of rehandling and truck movements. NON-BENEFICIAL DISPOSAL (permanent The material is suitable for disposal but needs to be dried out first before it can be There is no land available for this purpose. Flat land near the port is used for residential, tourism, cultural, conservation or agricultural Significant impacts on terrestrial environmental values to clear sufficient land No facilities in place currently. Dewatering, processing and material handling faculties