south taranaki bight environmental effects overview ... · 5 all#findings#arepreliminary...

All findings are preliminary and provided without prejudice www.ttrl.co.nz 1 October 2013

Trans-‐Tasman Resources Limited

South Taranaki Bight Iron Sands Project Preliminary Effects Overview

http://www.ttrl.co.nz/

1

All findings are preliminary and provided without prejudice 1 October 2013

Trans-Tasman Resources Limited (TTR) is seeking marine consents under the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Act 2012 (the EEZ Act) to undertake iron ore extraction and processing operations in a total project area of 65.76 square kilometres, located between 22 and 36 kilometres (12 and 19 nautical miles) offshore in the South Taranaki Bight.

TTR is committed to engaging the best scientific advice to study and manage its impacts on the environment. The preliminary findings in this report are based on research carried out by NIWA, AUT, NZIER, Boffa Miskell, Rob Greenaway and Associates, Croydon and Associates, Hegley Acoustics Consultants, Cawthorn Associates Ltd, and Fathom Consulting. The final reports will be publicly available as part of the notification process, which is planned for November 2013.

Project area

2


KEY ELEMENTS OF THE PROJECT

The iron sands target comprises a black, heavy, magnetic iron ore (known as titano-magnetite) that originated as crystals in volcanic rocks largely derived from Mount Taranaki, which over the past thousands of years have been washed down by various large rivers, transported along the coast by shallow-marine long-shore currents, and subsequently concentrated offshore by historical wave and wind action into offshore remnant beach and dune lag deposits located 22-36 km offshore (12-19 nautical miles offshore) in water depths of 19-42 metres.

The TTR Project involves the excavation of up to 50 million tonnes per year of seabed material containing iron sand, for processing on a Floating Processing Storage and Offloading Vessel (FPSO).

Around 10% of the extracted material will be processed into iron ore concentrate for export, with residual material (approximately 45 million tonnes per year) returned to the seabed as de-ored sediment via a controlled discharge at depth below the FPSO.

Excavation Seabed material will be excavated using one or two subsea sediment extraction devices (referred to Crawler ed by a slurry delivery pipe to the FPSO where it will be processed to separate out the iron ore. The Crawler will weigh around 350 tonnes, and will measure approximately 12 metres long, around 8 metres wide and around 8 metres high.

3


Extraction Methodology When the Crawler operation commences, the suction head will engage the seabed in the pre-defined target area, pumping seawater via nozzles to the extraction face to fluidise the sediment to facilitate extraction by pumping into the delivery line and then to the FPSO. The total width of the mining cut of the Crawler boom is approximately 12 metres wide allowing for an approximate 1 metre overlap on both sides of the cut to minimise losses.

Based on current estimates, a Crawler will have an annual throughput capacity of up to 8,000 tonnes per hour (and up to 50 million tonnes per annum).

The Crawler will extract sand in 300 m × 300 m blocks to the base of the mineralisation, and will extract the full depth of the face (from the seabed to as deep as 11 metres depending on resource distribution) during each extraction sequence. The length of each mining run will be a function of FPSO length (330 m). At the end of each cut the Crawler will turn 180° and mine the adjacent cut.

-depositing de-ored sand as it goes. This happens very slowly at speeds of around 70 m/hour.

4


De-ored Sediment Deposition

As the Crawler continues into the mining sequence, de-ored sand will be re-deposited into previously worked-over areas in turn. This is shown diagrammatically in the figure below, whereby the FPSO will re-deposit into the adjacent block to the north of where the Crawler is excavating. For example if the Crawler is excavating from area 17, the FPSO will be re-depositing de-ored sand into area 15 and so on.

Approximately 90% of the extracted sediment will be returned to the seabed generally into previously worked areas. This will be as a thick slurry containing 70 to 80% sediment by weight.

This deposition will occur at the opposite end of the FPSO to the crawler and will be from a large discharge tube positioned approximately 4 m above the seabed. At this height the delivery end of the discharge pipe will not be swamped by the tailings.

Processing

process is to separate the titano-magnetite using a combination of conventional screening, magnetic separation and grinding, to produce a product with a target mass yield in the order of 10% from the raw sediment. This process does not involve the discharge of any chemicals or the use of heat. The initial screening will remove material greater than 2 mm in size, as that has been shown to contain no titano-magnetite.

Layout of the FPSO

Deposition pipe

5


Transfer and Export Iron ore concentrate from the FPSO will be transferred using freshwater as a slurrying medium, to the Floating Storage and Offloading vessel (FSO), where it will be de-watered and stored ready for transfer to bulk carrier vessels for export to world markets. Freshwater is needed to reduce the chloride levels in the concentrate. Transfers from the FSO to the bulk carrier vessels will take place near the project area, although during adverse weather situations these transfers will take place in a location where there are acceptable ocean conditions.

Fuel All of the production operations on the FPSO will be powered by electrical generators using Heavy Fuel Oil (HFO. for replenishment of HFO is to utilise a ship-to-

Ports TTR is likely to use a number of different ports to support the vessels engaged in the project depending on the services required and the method of delivering them. The ports of Whanganui, New Plymouth and Nelson are the closest to the extraction site in that order and each could offer the project support in different ways according to their capabilities.

Navigational Exclusion TTR will apply to establish an exclusion zone with a radius of one nautical mile around the FPSO when moored at the mine site to safeguard other ocean users, members of the public and project vessels from harm. In the context of the South Taranaki Bight this is a relatively small area. This exclusion zone will move with the FPSO.

Ballast Water/Antifouling The vessels employed for the TTR project will be fully compliant with the requirements of the International Convention for the Contr

ssels will also be required to comply with the IMO Biofouling Guidelines 2011 (Resolution MEPC 207(62), for the co iofouling to minimise the transfer of invasive aquatic species.

Example of trans-‐shipment from a FSO to a bulk carrier export vessel

6


Personnel In total around 200 personnel will be required for operation of the FPSO, the FSO and the Anchor Handling Tug. Approximately 50 additional total full time equivalents will be employed by TTR, including administration, engineering and environmental staff and contractors. These personnel w ill largely be based in Taranaki and in Wellington. As well, there will be other indirect on-shore employment to service the vessels and the operation.

Risk Management and Operating Procedures

TTR is developing a comprehensive set of health and safety procedures many of which relate to activities and areas which when undertaken appropriately will avoid remedy or mitigate adverse environmental effects. TTR will develop a comprehensive Crisis and Emergency Response Plan (CEMP) to address risks to human health and the environment. This CEMP will set out measures for all concerned parties to assure proper responses to, and ultimate recovery from, an emergency or crisis that threatens personnel and/or property. TTR has adopted a number of industry best practice measures, based around a range of recognised International and NZ Standards and industry best practices.

7


ASSESSMENT OF POTENTIAL EFFECTS

ut below.

FPSO Anchoring The anchor deployment for the FPSO involves installation of standard fluke anchors connected by tensioned steel cables directly to the FPSO. These anchors will be moved on a regular basis as needed by the movement of the FPSO. Other than the direct disturbance to the seabed caused by the anchor placement, movement of the FPSO, and removal and re-deployment the anchor system will have no measurable environmental effect.

Presence of FPSO The presence of the moored FSPO will have a negligible effect on the nearshore wave climate with no consequent influence on coastal processes, and it will provide a potentially significant aggregation habitat for pelagic fish.

Crawler Movement The Crawler will manoeuvre on the seabed using two hydraulic-driven tracks. This will cause seabed compression and will only affect marine biota immediately under the tracks in the short period when the Crawler is first placed on the seabed. These effects are insignificant, especially in comparison with the extraction process discussed in the following section.

Extraction The extraction process will initially result in formation of excavation pits in the seafloor. The influence of pits and mounds on the wave climate and consequent effects on coastal processes and surfing has been assessed and found to be minor. All immobile benthic organisms in the mining area will be entrained into the Crawler intake and pumped to the FPSO. This extraction and pumping process is assumed to result in complete de-faunation.

De-ored Sediment Deposition De-ored sand will be re-deposited from the discharge pipe, around 4 m above the seabed, and may initially result in a mound on the sea floor. Depending on the iron ore grade of the seabed sediment being extracted, around 90% of the sediment will be returned to the seabed, mostly into previous ly mined areas. The re-deposition of de-ored sand will change the nature of the seabed in the deposition area. The de-ored sand is assumed to be de-faunated and upon re-deposition on the seabed, will take time to become re-colonised by benthic organisms. The duration of this re-colonisation determine the extent of the ecological effect of the re-deposition process.

8


Adverse water quality (chemical) effects and effects of sediment re-suspension are not anticipated to affect marine life. The principal potential water column effect of the de-ored sand re- . The degree to which this is apparent will vary throughout the South Taranaki Bight but generally this appears to be of low effect, especially when considered relative to the background suspended sediments.

Other Discharges Process outputs from the Reverse Osmosis (RO) plant are freshwater and brine. Brine will be discharged with the de-ored sediment. This will cause a localised and relatively minor change in salinity with no adverse environmental effect after anticipated rapid initial environmental mixing. There will be no discharge of RO cleaning chemicals. Overflow water from the hydro-cyclones on the FPSO -cyclone overflow p -ored sediment deposition pipe. The effects of this discharge have been evaluated in detail in respect of plume modelling. The hyperbaric filter filtrate discharge (from the FSO) will involve the discharge of freshwater containing small levels of sea-salts that will have been washed from the concentrate. These will have a negligible environmental effect after rapid initial mixing. TTR will monitor dissolved concentrations of copper and other trace metals in the beneficiation plant discharge to verify compliance with ANZECC & ARMCANZ guidelines.

Ship-to-Ship Concentrate Transfer The transfer of concentrate from the FPSO to the FSO will via a freshwater slurry. A noted above this freshwater will contain small levels of dissolved sea salts. The transfer of concentrate from the FSO to the export bulk carrier will be by conveyor and will involve no discharges or other effects.

Ship-to-Ship Fuel Transfer pillage.

Noise and Vibrations The FPSO and Crawler will generate noise, but this has been assessed has having no more than minor effect on fish and marine mammals.

9


BROADER ENVIRONMENTAL ASPECTS Anticipated effects on the environment are summarised as follows.

Currents, Longshore and Cross Shelf Sand Transport The studies show there is little connection between seabed sediments in the extraction area and shoreline sediment regime. Seabed sand in the area of the extraction operations some 22 to 35 km off the coast is not a recognised source for sand on the beaches. Therefore sand extraction will not have significant effects on sand supply to the beaches and will not promote beach erosion.

Waves The overall conclusion from the scenario-based wave modelling is that the proposed sand extraction operations will have minor effects on the physical driver of waves by refracting (bending the wave direction) and shoaling (changing the wave height) as they pass over the modified seabed. The changes in both wave height and direction are very small. Similarly, the presence of the FPSO will not cause any wave shadowing effects on the coastline.

Surf Breaks Given the location over 20 km offshore of the closest breaks, and minimal change to the wave climate, effects on surfing waves are predicted to be insignificant.

Natural Landforms and Geomorphic Character Analysis of the effects of sand extraction on waves reaching the shore suggests the changes in waves characteristics are mostly sma ll (changes in wave height of the order of about 100 mm on a 2.4 m wave, and changes in direction less than 1 degree), which will have no influence on beach state and geomorphic character.

Deposition of Substances on the Shore Fine sediments generated by sand extraction operations, if deposited on the beaches will be quickly winnowed from the beach s ediment by wave action and transported offshore and thus not build-up on the beach.

Coastal Erosion and Accretion Sand extraction offshore will have no significant effect on the beaches in terms of the natural hazard processes of erosion and accretion, which under natural conditions are highly variable.

Change in height of 3 m waves from the WSW, 16 s period

10


Sediment Plume and Sediment Re-Suspension Plumes from TTR Project activities will potentially extend to the east-southeast, reaching the coast between Patea and Whanganui and with a long tail of low concentrations following the coast to the South. For extraction at the 12 nm limit (inner boundary of application area) the highest surface concentrations occur at the source location and are 2.5 5 mg/L (median) and 10-20 mg/L (99th percentile).1 For extraction further offshore, the plume is located further offshore and the nearshore concentrations are somewhat lower. In both cases the mining-derived sediment plume contributes markedly to the total suspended sediment concentrations within a few kilometres of the source but is insignificant relative to the natural suspended sediment concentrations near the coast. The figure to the right compares the median scenario true water colour for various points along the South Taranaki coastline under natural and mining conditions. Note the representation of true colour in the tiles are computer screen and printer dependent. The figures on page 11 compare the median and 99th percentile sediment surface concentrate created from extraction at the 12 nm limit, showing the natural suspended sediment concentration levels, the amount of sediment derived from the mining activity, and the combined natural and mining suspended sediment concentrates. Note the colours are indicative of the in-water concentration of sediment and do not reflect the actual sediment plume.

1 99th percentile is the value that exceed the data 99% of the time, or conversely the value that is exceeded 1% of the time. The 99th percentile will be used as a robust indicator of the high end of the distribution of sediment surface concentrate (SSC).

11


Median near-‐surface concentration of suspended sediment from Source A. Notes: a) Natural SSC; b) mining-‐derived SSC; c) natural plus mining-‐derived SSC. Black lines indicate the project area and the 22.2 km territorial limit. An open circle in panels b and c indicates the source location

99th percentile near-‐surface concentration of suspended sediment Source A.

Notes: a) Natural SSC; b) mining-‐derived SSC; c) natural plus mining-‐derived SSC. Black lines indicate the project area and the 22.2 km territorial limit. An open circle in panels b and c indicates the source location

12


Benthic Ecology, Fish and Birds TTR undertook an ecological effects evaluation using a Risk Assessment Framework. Three particular risk effects were identified, in relation to effects on benthic organisms in the vicinity of the direct extraction and deposition area, and potential impacts on biogenic offshore habitats. These effects are: 1. Loss of benthos at extraction site due to sand extraction, and smothering and

burial from de-ored sand re-deposition. A particular effect was associated with direct impact on the habitat of the tubeworm Euchone sp. A.;;

2. Impact on near-field benthos due to de-ored sand deposition (same effect as

above but at lower deposition rates across a wider area than the direct extraction and deposition zone);; and

3. Impact on offshore biogenic habitats due to potential effect of elevated sediment

loads in water column. In general, after an initial disturbance to seabeds such as in the South Taranaki Bight,

ioneeri organisms, such as small, tube-dwelling polychaetes and small bivalves colonise the surficial sediments. These opportunistic taxa occur in relatively high abundances and low diversity and over time are replaced by larger, longer-lived and deeper-burrowing species. successional species such as the polychaete Euchone sp. This characteristic will facilitate re-colonisation over timeframes of a few months to a few years, depending on the species. The de-ored sand discharged back to the seabed will have a similar particle size distribution to that present on the seabed prior to extraction. Therefore grain size change should not pose an impediment to recolonisation.

methodology and anticipated excavation rate means that the extraction and deposition impact at each site will be of very short duration, meaning that there will be ongoing opportunity for recovery on a continuous basis throughout the year.

relatively small area of the seabed within the South Taranaki Bight disturb around 6% of the project area or 1.93 km2. The TTR Project is not considered to present any adverse issues in respect of protection of biological diversity in the broader South Taranaki Bight area notwithstanding localised effects in the extraction and immediate deposition areas. No rare or vulnerable ecosystems or habitats of threatened species have been identified as being potentially affected by the TTR Project.

Euchone sp A specimens

13


Marine Mammals The South Taranaki Bight generally is not a recognised habitat for marine mammals. No interactions with marine mammals are anticipated. In any event , TTR will establish protocols for encounters with marine mammals to ensure adverse effects do not arise.

Discharges to Air Predicted ground level concentrations of air discharge contaminants will be below relevant health-based air assessment criteria and specifically the NZ Air Quality Standard.

Lighting Operational lighting on the ships will focus on operational areas on the deck of the FPSO to ensure a safe 24 hour working environment. Light will be designed to minimise light spill.

Archaeological No shipwrecks are known to be present within the project area. The potential for encountering shipwrecks in the South Taranaki Bight EEZ is low, but cannot be

o ensure that statutory requirements and processes are followed in the event that nineteenth century wreckage is encountered.

Public Access on will not change in the future with sand extraction offshore, and therefore public access to the marine environment

will not be hindered. The continual cycles of cut and fill on the beaches due to natural events will hinder access from time to time as they have in th e past.

Visual Effects (Seascape) and Visual Amenity Visual effects of the FPSO and other vessels will be minor, due largely to distance. In addition, the visual bulk of the FPSO vessel, being the area below a deck level of 15 m, will not generally be visible from the shore. While the FPSO may be clearly visible from locations within 10-15 km of the vessel, the visual effects in the context of the wider seascape setting will be relatively minor. Where there may be effects as a result of variations of suspended sediment concentrations from offshore generated plumes from the Project, the effects of these are likely to be relatively minor. Visual effects may be apparent from recreational and commercial aircraft, and while these effects will be variable and transient, the scale of effects will generally be minor.

14


Recreation Adverse effects of interest to recreation and tourism are likely to be only local to the immediate vicinity of the extraction area, and will relate to exclusive use of the marine setting, local turbidity effects (up to 10 km from the site) and short-term effects on habitat in recently mined seafloor. Based on previous research, there appears to be very little fishing activity in the immediate vicinity of the extraction area (as shown by the figure to the right). Being so far offshore any exclusion around the FPSO when operating in the extraction area is unlikely to have any effects at the regional level. With regard to the North and South Traps, given the location of the traps it is unlikely there will be any adverse effects. While there may be variations in suspended sediment plume concentrations from the Project, these are likely to be relatively minor and will not adversely affect the special features and values of the traps.

Commercial Fishing It is expected that there will be no negative existing commercial fishing rights granted under the Fisheries Act 1996 with regard to quota value, downstream businesses, or fish stock sustainability as a consequence of spatial displacement. With appropriate management of sediment dispersal, no significant off-site impacts on commercial fisheries are anticipated. TTR plans to work with commercial fishers in the region to develop conditions of consent to ensure

issued under Fisheries Act.

Human Health The TTR Project will not involve the discharge of any contaminants which might potentially result in adverse effects on human health. Noise levels generated on the vessels will be managed to avoid adverse human health effects (from an occupational safety perspective) particularly for employees and contractors working on the project.

Inshore boat angling activity in the South Taranaki Bight adapted from Hartill et al 2011

15


ECONOMIC BENEFITS TTR iron sands will contribute the size of the New Zealand economy. The specific preliminary results from the economic impact assessment are as follows:

it will raise the level of exports by $147 million per year the Gross Domestic Product (GDP) will increase $302 million per year during the project, as a result of the increased exports and the flow-on effects through

the economy included in this increased GDP are taxes and royalties to the New Zealand government from TTR, estimated at $54 million annually - the royalty rate is

approximately 10% of pre-tax profits overall, government expenditure is estimated to be $71 million greater per year as a result of the project, as a result of the direct contributions of TTR and the

increased economic activity household consumption will increase by $104 million per year. This is a measure of the welfare benefits to New Zealand of the increased economic activity.

also benefit the wider regional economy by:

raising million per year increasing employment directly by around 250 jobs within the TTR project, and by around 170 in jobs throughout the rest of Taranaki regi on

The gains are not only confined to the mining sector. The benefits are likely to flow onto related sectors (for example business services) and sectors that benefit from a growing regional economy (retail and service sectors). There will be increased opportunities for residents of South Taranaki and Whanganui to access training and work experience that is relevant to the range of positions associated with TTR s operations.

MITIGATION MEASURES AND CONDITIONS TTR has only a limited ability to vary the Project scope and retain a commercially viable operation. However, there are a number of measures that have already been incorporated in Project design and there are a number of operational measures which collectively enable TTR to avoid, remedy or mitigate adverse effects. TTR, in conjunction with existing interests, will develop a list of volunteered conditions to address the potential effects that could arise from its proposed activities.

ENVIRONMENTAL MANAGEMENT PLAN (EMP) FRAMEWORK TTR has adopted an EMP framework based around widely accepted quality management concepts. TTR proposes that the EMP will be finalised in collaboration with stakeholders.

16


NEXT STEPS TTR submitted a mining permit application to New Zealand Petroleum and Minerals (NZPAM) in July 2013. The application will be assessed by NZPAM for technical

h and safety. TTR aims to lodge marine consent applications with the Environmental Protection Authority (EPA) in October 2013. Once the application has been accepted as complete by the EPA, it will be publicly notified and public submissions will invited. Once mining permits and marine consents have been granted, TTR can start work towards final engineering, procurement and cons truction. The objective is to start commercial extraction of iron ore at the beginning of 2016. For further information please visit www.ttrl.co.nz or contact the Iwi and Community Relations Manager, Rose Austen-Falloon, at rose.austen-[email protected].

Trans-Tasman Resources Limited PO Box 10 571 Wellington 6143 NEW ZEALAND

Phone: +64 4 499 8875 Website: www.ttrl.co.nz

http://www.ttrl.co.nz/

mailto:[email protected]

south taranaki bight environmental effects overview ... · 5 all#findings#arepreliminary...

Documents