Environmental and Social Impact Assessment (English Translation)
Project Number: 49222-001 May 2016
INO: Tangguh LNG Expansion Project
Volume 2: ANDAL Chapter II 2.1
Prepared by BP Berau Ltd.
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CHAPTER II ENVIRONMENTAL BASELINE
2.1 GEOPHYSICS AND CHEMISTRY
2.1.1 Climate and Meteorology
Climate is defined as average condition of physical elements of the atmosphere over a long period, from tens to millions of years (IPCC, 2001). The World Meteorological Organization (2003) explains that the classic period to determine climate in a region is 30 years. However, based on the study by Coumou (2011), the duration of climate data of ten years is considered sufficient to illustrate the climatic condition in tropical areas due to the relatively homogenous climate fluctuation. Thus the climate condition of Tangguh LNG, located on the Southern Shore of Bintuni Bay waters in Teluk Bintuni Regency, West Papua Province, is illustrated using climate elements with minimal period of ten years. Physical elements of atmosphere that are used to analyze the climate condition in Tangguh LNG consist of rainfall, humidity, air temperature, evapotranspiration, wind speed and wind direction.
Physical elements of the atmosphere consist of humidity, air temperature, wind speed and direction in Tangguh LNG area are analysed using data obtained from AERMET MM5 Worldwide Meteorological Data in the project site at coordinates 2,4º S and 133,1º E as shown in Map II-1. This is due to the fact that the nearest meteological stations to the Tangguh LNG area are located quite far, in Fakfak Meteorology Station (± 105 km) and Manokwari Meteorology Station (± 206 km). Additionally, the availability of data (temperature, air humidity, pressure as well as wind direction and speed) at the meteorology station located at AWS (Automatic Weather System) Sierra Bravo in the Tangguh LNG area is less than 50%. Therefore, it is considered that the station is not representative for the condition of atmospheric physical elements at the project location.
Data of atmospheric physical elements in the form of rainfall is acquired from TRMM (Tropical Rainfall Measuring Mission) radar type 3A12 V7 in the period from 1998 to 2012 through http://disc.sci.gsfc.nasa.gov/precipitation/tovas supported by rainfall data from Lister (2002) to analyze rainfall of the region around Tangguh LNG.
As observation data, rainfall data of Fakfak Meteorology Station (1958-1983 and 2004-2008) as well as Manokwari Meteorology Station (1998-2011) are used as found in Appendix II.6 Meteorology Data. The next phase is to perform calibration and validation toward the radar data using the observation data.
Unlike the five other atmospheric physical elements, evapotranspiration data in the Tangguh LNG area is acquired from estimation using Aquastat based on the study made by Lister (2002).
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2.1.1.1 Rainfall
From data processing using TRMM radar data and observation data at Fakfak and Manokwari meteorology stations as well as Lister (2002), average monthly regional rainfall for 1998 – 2012 were obtained at coordinates 132º -133,8º E and 1,7º – 3,0º S as well as point rainfall at coordinates 2,4º S and 133,1º E as shown in Figure II-1.
Figure II-2 and Figure II-4 illustrate spatial rainfall distribution around the project site, while Figure II-3 portrays rainfall distribution in Indonesia. Referring to Figure II-1 and Figure II-3 it may be seen that average regional monthly rainfall in Tangguh LNG during a 14 years period was 240 mm with lowest rainfall occured in the months of July and August. Highest regional rainfall occurred in the month of May, reaching 288 mm. Referring to Figure II-1, Figure II-2 and Figure II-4 and supported by Figure II-3, it is shown that the rainfall type at the project location is local type rainfall.
Source : Radar TRMM (Tropical Rainfall Measuring Mission) tipe 3A12 V7 (http://gdata1.sci.gsfc.nasa.gov/daac-bin/G3/gui.cgi?instance_id=TRMM_Monthly), Lister (2002) Figure II-1 Rainfall Pattern in the Tangguh LNG Area (132,00 -133,80 E and 1,70 – 3,00 S) and Point Rainfall Pattern at Tangguh LNG (2,4º S and 133,1º E)
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Location of AERMET MM5 Meteorological Data (1998-2012) Location of meteorological data in Manokwari Meteorological Station (1998-2011) Location of meteorological data in Fakfak Meteorological Station (1958-1983 and 2004-2008)
Boundary of Climate Assessment Area
Map II-1 Meteorological Data Locations
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Local type rainfall is characterized by unimodial rainfall pattern (one peak rain) referring to Figure II-1 and Figure II-4. Regional rainfall at coordinates 132,0° - 133,8° E and 1,7° – 3,0° S with local type believed to be caused by the influence of physical environment condition. Physical influence may be expanse of water or sea, high mountains and intensive local warming (Tukidin, 2010). Overall, rainfall in the vicinity of Tangguh LNG is very high with average annual rainfall of 2.938 mm.
Source : TRMM (Tropical Rainfall Measuring Mission) Radar type 3B43, 3A12 and 3A25 V7 Figure II-2 Spatial Distribution of Average Monthly Rainfall over a 14 Year Period (1998 – 2012) in the Bintuni Bay Area
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Source : TRMM (Tropical Rainfall Measuring Mission) Radar type 3A12 V7 Figure II-3 Rainfall Distribution Pattern in Indonesia
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January February March April
May June July August
September October November December
Source : Radar TRMM (Tropical Rainfall Measuring Mission) tipe 3A12 V7 (http://gdata1.sci.gsfc.nasa.gov/daac-bin/G3/gui.cgi?instance_id=TRMM_Monthly) Figure II-4 Spatial Distribution of Average Monthly Rainfall over a 14 Year Period (1998 – 2012) in the Bintuni Bay Area
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2.1.1.2 Air Temperature
Based on data of air temperature in Tangguh LNG through data taken from AERMET MM5 Worldwide Meteorological Data during a ten-year period (2002 – 2011) (Figure II-5), it is known that the lowest temperature in Tangguh LNG occurs in the month of July, at 25.3 ºC. Minimum temperature in the study area during a ten-year period occurred in the dry season in which the sun moved north of the equator. At the start of the wet season, generally in September, temperature in the study location tend to rise. Absolute maximum temperature was recorded in the month of December, at 26.6º C. Overall, air temperature in the study location ranged between 25.3º C to 26.6º C with average monthly temperature of 23º C. Fluctuation of average monthly temperature during ten years (2002 – 2012) is shown in Appendix II.6 Meteorology Data. Therefore, temperature condition in the study location was in the warm category with air temperature fluctuation tending to be stable. Dynamics of air temperature will further affect atmospheric stability.
Source : AERMET MM5 Worldwide Meteorological Data (2002-2011) Figure II-5 Graph of Average Monthly Temperature in Tangguh LNG (2002 – 2011)
Through hourly air temperature data obtained from AERMET MM5 Worldwide Meteorological Data, maximum air temperature during a ten-year period (2002 – 2012) occurred at 15:00 Indonesia Eastern Time with air temperature of ± 28.3º C. This condition indicates that at 15:00 Indonesia Eastern Time, solar radiation was mostly used to heat the air near the surface or known as soil heat flux and sensible heat flux.
Minimum air temperature over a ten-year period (2002 – 2012) occurred at 5:00 Indonesia Eastern Time. This condition illustrates that heat originating from long
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wave radiation emitted by the earth’s surface decreased in line with short-wave radiation emitted by the sun.
2.1.1.3 Relative Air Humidity (RH)
Relative air humidity (RH) is one of the atmospheric physical variables illustrating the ratio between actual air pressure and saturated air pressure. Relative air humidity can illustrate the quantity of water vapor in a particular location.
Based on relative air humidity data during ten years as shown in Figure II-6, the climate condition in Tangguh LNG is classified as humid, with average humidity 83.2%. Fluctuation of humidity level is not significant during seasonal change. This condition is shown with standard deviation of air humidity of 1%. In the months of April and May, relative humidity reaches 82.5% and 82.9%. Lowest humidity occurs in October at 81.0%. Values of monthly humidity in a ten-year period (2002 – 2012) is shown in Appendix II.6 Meteorology Data.
Source : AERMET MM5 Worldwide Meteorological Data (2002-2011) Figure II-6 Graph of Average Monthly Humidity in Tangguh LNG (2002 – 2011)
Similar to air temperature, humidity is also one of elements of weather affecting atmospheric stability. Low air humidity may hinder surface warming by solar radiation (Fairuzi, 2012). During the day, air temperature is relatively higher than at night so that water vapor content is lower than at night. This condition enables maximal air mass rising, therefore it enables various air pollutants to rise from the surface to the atmosphere.
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2.1.1.4 Air Pressure
Air pressure is energy used to move air mass in every unit of area. In areas receiving the sun’s heat, the air will expand and rise with low air pressure.
Shifting of the sun’s orbit causes fluctuation of seasonal temperatures, mainly in the middle latitudes. Air temperature will cause air volume to expand and contract. When air expands, it will become less dense and consequently pressure will decrease, on the contrary when air volume contracts, air density will become greater and cause pressure to rise.
Based on the principle that pressure is inversely proportional to temperature, this phenomenon is also shown by inverse proportion of average monthly temperature around Tangguh LNG with average monthly air pressure. In the months of July and August average monthly temperatures are at their lowest over one year and average monthly air pressure is highest around Tangguh LNG.
The presence of the sea near the location of Tangguh LNG serves to influence air pressure fluctuation, as the sea supplies water vapor in the air (through the evaporation process). Additional water vapor in the air will cause air pressure to rise. This phenomenon also proceeding around the Tangguh LNG area as shown in Figure II-7 indicates that the months of July and August have relatively high air pressure, of around 1,009 mBar. Average air pressure throughout the measurement period was 1,007 mBar.
Source : AERMET MM5 Worldwide Meteorological Data (2002-2011) Figure II-7 Graph of Average Monthly Air pressure (2002-2011) to Average Monthly Air Temperature (2002-2011)
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2.1.1.5 Wind
The windrose diagram illustrates distribution of wind speed and direction (BMKG, 2000). The Windrose at Tangguh LNG is processed using data of wind speed and direction obtained from AERMET MM5 Worldwide Meteorological Data during ten years (2002 - 2011) and built using WRPlot software.
Based on monthly windrose for a ten-year period (Figure II-8) and overall distribution of wind speed (Figure II-10), it is known that 18% of wind direction comes from the West with average wind speed of 8.8 m/s and 10% wind direction blows from the Southeast at speed of 5.7 m/s.
Overall wind class frequency distribution (Figure II-10) also shows that 4.4% of wind speed frequency is calm wind class (wind speed ≤0.5 m/sec and with no direction). Wind speed frequency of calm wind class occurs mostly in the wet season.
Referring to Figure II-8 and Figure II-9, it was found that in November to May, dominant wind direction blows from the west with frequency of occurrences of 25.3% and average range of wind speed from 2.1 m/sec to 3.6 m/sec with frequency of occurrence of 35.6%. Meanwhile, from June to October, dominant wind direction is from the southeast with frequency of occurrences of 20.7% and from the south at 15.6%, with range of average speed of 2.1 m/sec to 3.6 m/sec with frequency of occurrences of 39.9%.
Overall, dominant annual wind direction in the Tangguh LNG is from the west with frequency of occurences of 17.1% and from the southeast with frequency of occurences of 10.5%. Average annual wind speed ranges between 2.1 m/sec to 3.6 m/sec with frequency of occurences of 37.4% (Figure II-10).
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January (2002-2011) February (2002-2011) March (2002-2011) April (2002-2011
May (2002-2011) June (2002-2011) July (2002-2011) August (2002-2011)
Source : MM5 data by Lakes Environmental (http://www.weblakes.com/) 2002-2011 Figure II-8 Monthly Windrose in the area of Tangguh LNG
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Source : MM5 data by Lakes Environmental (http://www.weblakes.com/) 2002-2011 Figure II-9 Average Annual Wind Direction and Wind Speed (Windrose) Around Tangguh LNG
Figure II-10 Wind Class Frequency Distribution around Tangguh LNG
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2.1.1.6 Evapotranspiration
Evapotranspiration (ET) is defined as the overall quantity of water originating from soil and water surface (evaporation), re-evaporation of rainwater from the surface of vegetation (interception) and groundwater evaporation to the atmosphere through vegetation (transpiration). Based on determinant factor, ET is differentiated as potential evapotranspiration (ETP) and actual evapotranspiration (ETA). ETP is influenced more by meteorological factors, while ETA is affected by plant physiology and soil elements.
Referring to the principle that ETP is the amount of evapotranspiration affected greatly by meteorological factors, estimation of evapotranspiration in the Tangguh LNG was done through estimation of potential evapotranspiration level in the area. The estimated high potential evapotranspiration was based on data from Aquastat and Lister (2002). The both data sources possess high resolution and are results of ETP estimates on the ground surface toward global climate regions.
Table II-1 Potential Evapotranspiration in Tangguh LNG (2002) Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Potential 116 107 116 110 107 94 98 104 110 119 111 112 Evapotranspiration (mm) Source : Lister (2002).
From the data of potential evapotranspiration in the Tangguh LNG from Aquastat and Lister (2002), the ETP graph as presented in Table II-1 and Figure II-11 was obtained. Referring to Table II-1 and Figure II-11, ETP at the Tangguh LNG tends to be stable ranging between 94 mm and 119 mm. The high ETP at the Tangguh LNG is affected by air temperature and high humidity at the location. Fluctuation of monthly ETP level is also proportionate to the increase of wind speed at the Tangguh LNG that was obtained from average wind speed over a ten-year period at the Tangguh LNG (Figure II-11).
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Source : TRMM (1998 – 2012), Lister (2002) and AERMET MM5 Worldwide Meteorological Data. Figure II-11 Average Rainfall (mm), Potential Evapotranspiration (mm) and Wind Speed (m/sec)
2.1.1.7 Climate Types
The World Meteorological Organization (2009) explains that the application of climate classification system is based on its purpose. In the forestry sector, climate classification systems such as Thornwaite and Schmidt-Ferguson are used. For the agricultural sector, the climate classification system commonly used is the Oldeman climate classification system. In global climate analysis, the Holdridge and Budyko climate classification systems are used . Analysis of past climate (paleoclimatology) used the Bergeron and Spatial Synoptic climate classification system. For the purpose of local climate analysis, the commonly used classification system is the Koppen climate classification system.
Based on the principles of climate classification system , the Koppen climate classification system is used for the analysis of climate type in the Tangguh LNG, which is based on temperature, average annual rainfall and monthly annual rainfall. The Koppen climate classification is divided into five climate classes, i.e. type A, B, C, D and F as shown in Table II-2.
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Table II-2 Formulation of Koppen Climate Classification System Type Description Criteria A Equatorial tropical climate Minimum temperature ≥ 18º C Af Equatorial tropical rainforest climate Lowest rainfall ≥ 60 mm Am Equatorial monsoon climate Annual rainfall ≥ 25 (100-lowest rainfall ) As Equatorial savanna climate with dry Lowest precipitation < 60 mm in summer summer Aw Equatorial savanna climate with wet Lowest precipitation < 60 mm in winter summer B Arid climate Evaporation > Rainfall
BS Steppe climate Annual precipitation < 5 Pth*
BW Desert climate Annual precipitation ≤ 5 Pth* C Warm climate -3º C < lowest temperature < 18º C Cs Warm climate with dry summer Lowest precipitation in the summer < Lowest precipitation in winter. Highest precipitation in winter > 3 times lowest precipitation in summer, and lowest precipitation in summer < 40 mm Cw Warm climate and dry winter Lowest precipitation in the winter < Lowest precipitation in the summer and highest precipitation in summer > 10 times lowest precipitation in winter Cf Warm and wet climate Other than Cs and Cw D Cold climate Lowest temperature ≤ -3 º C Ds Cold climate with dry summer Lowest precipitation in summer < Lowest precipitation in winter, highest precipitation in winter > 3 times lowest precipitation in summer, and lowest precipitation in summer < 40 mm Dw Cold climate with dry summer Lowest precipitation in winter < Lowest precipitation in summer and highest precipitation in the summer > 10 times the lowest precipitation in the winter Df Cold wet climate Other than Ds and Dw E Polar climate Lowest temperature < 10 º C ET Tundra Climate 0 º C ≤ maximum temperature < 10 º C EF Frost Climate Lowest temperature < 0 º C Source: Kottek (2006). * Pth is defined as follows if annual rainfall occurs in the winter, Pth = 2 (annual air temperature), if
annual rainfall occurs in summer, Pth = 2 (annual air temperature) +28, if rainfall only occurs in
summer or wet season, Pth = 2 (annual air temperature)+14.
Based on Table II-2 and considering the condition of atmosphere physical elements as described in Sub-chapter 2.1.1.1 to Sub-chapter 2.1.1.6, the climate type in the Tangguh LNG area is climate type of Af. This is based on average monthly temperature in the study area of 26.1 ºC with maximum monthly temperature of 26.6 ºC and minimum monthly temperature of 25.3 ºC and average annual rainfall (CH) in Tangguh LNG area at 2.938 mm with monthly rainfall > 60 mm. The Af climate condition in the project location indicates the area with climate elements tending to be stable and wet. Fluctuating variability of climate elements of rainfall, temperature, humidity and other elements do not obviously differ from month to month.
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2.1.1.8 Influence of Climate Change
In general, Indonesia lies on the equator and this is the main factor affecting weather and climate conditions in Indonesia. The climate in Indonesia is generally divided in three climate patterns as shown in Figure II-12. Region A experiences Australian monsoon and occurs in a large portion of the southern regions of Indonesia, region B shows condition of semi-monsoon, while region C (marked by red disconnected lines) experiences anti-monsoon/Indonesia through flow climate.
(Source : Edvin A. et al 2003 in LAPAN/ National Aeronautics and Space Agency, 2009 Figure II-12 Map of Indonesian Climate Regions
Climate change will have an impact on human lives, possibly in the form of lower food production, rising sea surface levels, longer dry seasons and shorter wet seasons with higher intensity. This condition is believed to be able to occur in most of the Indonesia territory, including the eastern part of Indonesia and West Papua.
The West Papua region is still predominantly covered by forest that are in good condition. Papua, including West Papua, is one of the regions with the largest forest area of lowland forest remaining in Indonesia.
Based on latest studies, the Papua region including West Papua, will also be influenced by climate change with high frequency of extreme climate conditions; for instance, occurrence of rain outside the forecasted period. Weather and climate- related disasters have side effects that are quite significant for community and economic condition, including: (i) landslides and erosion, mainly in the highlands, (ii) floods in a large portion of the islands, mainly the lowlands; (iii) drought in several islands that are often linked to El Nino condition. In the future, sea levels are estimated to continue to rise.
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Climate projections for 2050 are shown in Table II-3. Temperatures are predicted to rise until the middle of the 21st century. Variations in rainfall are unpredictable, however flood and drought might increase in intensity between now and the middle of this century.
Table II-3 Climate Variability Scenario for 2050 Using the MAGICC/Model for Assessment of Greenhouse Gases Affecting Climate Change and SCENGEN/Scenario Generator Model from IPCC Temperature increase (°C) Rise of seawater level (cm) Rain 0.9 – 1.45 12.5 - 16 Variability: 5.20 – 8.63% Probability of Change: 0.68 – 1.0 (likely causing flood or dry season) (Source: LAPAN/National Aeronautics and Space Agency)
Potential impact of climate change on the Tangguh LNG facilities and operations have been studied as part of the project technical design and development. This includes considerations of 100 year Tsunami events in the marine facilities design, high rainfall in most of the area, tidal waves and coastal abrasion due to natural phenomena in the area.
2.1.2 Ambient Air Quality
Ambient air quality data was obtained from observation results of two seasons, i.e. the dry season and wet season. Sampling during the dry season was undertaken from August 5th to August 16th, 2012, while sampling in the wet season was undertaken on October 27th and October 28th, 2012. In general, ambient air sampling was divided into two locations i.e. onshore and offshore. The onshore location was divided into two groups: (a) inside the Tangguh LNG area and (b) nearest settlement outside the Tangguh LNG area boundary. Sampling locations of ambient air in the dry season and wet season are shown in Map II-2 and Table II-4. The overall offshore locations are in the Tangguh LNG area.
Table II-4 Samples of Ambient Air and Noise
Sample Coordinates Dry Wet Location Type Location Point South East Season Season AQN-1 Onshore (Tangguh LNG - Forest) Proposed Jetty 02° 27' 18.8" 133° 06' 52.0" √ √ AQN-2 Onshore (Tangguh LNG - Forest) Proposed Airfield 02° 27' 06.1" 133° 09' 02.1" √ x Proposed LNG AQN-4 Onshore (Tangguh LNG –Open Area) 02° 26' 46.7" 133° 08' 03.8" √ √ Train AQN-6 Onshore (Tangguh LNG – Open Area) Proposed Jetty 02° 26' 56.3" 133° 06' 56.1" √ √ AQN-7 Onshore (Settlement) Tanah Merah Baru 02° 27' 40.1" 133° 06' 16.2" √ √ AQN-8 Onshore (Settlement) Arguni 02° 39' 22.2" 133° 32' 53.4" √ √ AQN-9 Offshore Offshore - OFA 02° 26' 02" 133° 01' 21" √ √ AQN-10 Offshore Offshore – WD 02° 20' 32" 132° 57' 31" √ √ AQN-11 Offshore Offshore - VRA 02° 15' 54" 133° 11' 07" √ √ AQN-12 Offshore Offshore 02° 22' 52" 133° 11' 47" √ √
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Parameters of ambient air quality analyzed include sulfur dioxide (SO2), carbon monoxide (CO), nitrogen oxide (NO2), tropospheric ozone (O3), hydrocarbon (HC), total suspended particulates (TSP), particulates of size less than or equal to 10 microns (PM10), particulates of size less than or equal to 2,5 microns (PM2.5) and lead (Pb). The measurement periods of each parameter were as follows:
• One hour for parameter SO2, CO, NO2 and O3; • Three hours for parameter HC; and • One hour interval with maximum sampling period of three times for parameters
of TSP, PM10, PM2.5 and Pb.
Overall results of ambient air quality measurement are presented in Table II-5 (dry season) and Table II-6 (wet season). The overall laboratory analysis results are shown in Appendix II.1 and Appendix II.2. Concentrations of ambient air quality parameters from the measurements in both the dry season and the wet season were compared with ambient air quality standard in accordance with Government Regulation Number 41 Year 1999 regarding Air Pollution Control. Concentrations of each parameter compared with the quality standard are shown in Figure II-13. In general, entire air quality parameters analysed had concentration values relatively far below the threshold limits of quality standard, which complies with Government Regulation Number 41 Year 1999 regarding Air Pollution Control.
In general, there are two main factors to determine concentrations of gas and pollutant particulates in ambient air i.e. the components of climate and residence time of pollutants in the atmosphere. The climate components include air temperature, air humidity, air pressure, rainfall and wind. The climate components greatly influence dilution, dispersion, physical-chemical transformation and pollutants transportation emitted. From previous climate description, it was known that air temperature in the Tangguh LNG area was in the warm category with air temperature fluctuations tending to be stable throughout the year, likewise, air humidity in the Tangguh LNG was categorized as humid, with average humidity of 83.2%. Fluctuations of humidity levels were not significant during seasonal change. Additionally, air pressure at the Tangguh LNG was relatively stable at approximately 1,000 mbar throughout the year. With sufficient stability of the three climate components in the Tangguh LNG location, it was estimated that the climate components do not significantly affect seasonal variation of air pollutant gas concentrations. Meanwhile, high rainfall in the Tangguh LNG location enabled occurrence of wash-out and rain-out in some ambient air quality parameters. With wash-out and rain-out of pollutant gases and particulates there is possibility of low concentration of pollutants in the Tangguh LNG location. Meanwhile, observing the tendency of wind speed with relatively low percentage of calm wind (average 4.4%), wind also contributes to the dispersion and transportation of air pollutants in the Tangguh LNG area.
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Map II-2 Sampling Locations of Ambient Air and Noise
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Table II-5 Ambient Air Quality and Noise Measurements in the Dry season Acceptable Onshore Offshore Limit of Duration of No. Parameter Unit Analytical Methhod Quality AQN-1 AQN-2 AQN-4 AQN-6 AQN-7 AQN-8 AQN-9 AQN-10 AQN-11 AQN-12 Measurement standard* Ambient Air Quality Sulfur 1 µg/Nm3 900 255 154 130 86 <20 355 60 66 67 77 Pararosaniline 1 hour Dioxide, SO2 Carbon µg/Nm3 2 Monoxide, 30,000 <1,140 <1,140 <1,140 <1,140 1,150 1,150 <1,140 <1,140 <1,140 <1,140 CO Anlayzer 1 hour CO* Nitrogen µg/Nm3 3 400 <5 <5 6 <5 6 <5 <5 <5 11 <5 Satzman 1 hour Oxide, NO2
4 Oxidant, O3 µg/Nm3 235 <1 <1 <1 <1 <1 <1 14 25 10 20 Chemiluminescent 1 hour Hydrocarbon, µg/Nm3 5 160 <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 GC-FID 3 hours HC* Particulate µg/Nm3 6 <10mm 150 8 8 9 12 9 13 15 11 17 17 Dust Analyzer Grab (PM10) Particulate µg/Nm3 7 <2,5mm 65 10 9 11 16 13 5 9 2 3 11 Dust Analyzer Grab (PM2.5) Total µg/Nm3 Suspended 8 230 19 20 22 32 24 19 19 13 19 26 Dust Analyzer Grab Particulates (TSP) 9 Lead, Pb µg/Nm3 2 <0,1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 GFAAS Grab
10 Noise, Lavg** dB - 4.7 41.1 54.2 40.8 49.5 53.2 55.3 55.3 57.0 62.8 Noise Levelmeter Grab Note : * Government Regulation No. 41 Year 1999 regarding Air Pollution Control ** MoE Decree No 48 Year 1996
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Table II-6 Ambient Air Quality and Noise Measurements in Wet Season Acceptable Onshore Offshore Duration of Limit of Analytical No. Parameter Unit Measuremen Quality AQN- AQ AQ AQ AQ AQN- AQN AQN- AQN- AQN- Method t standard* 1 N-2 N-4 N-6 N-7 8 -9 10 11 12 Ambient Air Quality Sulfur Dioxide, µg/Nm3 <2 1 900 44 *** <20 34 127 <20 <20 <20 <20 Pararosaniline 1 jam SO2 0 Carbon µg/Nm3 <1,1 1,3 2 30,000 1,490 *** <1,140 1,490 1,260 <1,140 1,370 <1,140 CO Analyzer 1 jam monoxide, CO* 40 70 Nitrogen Oxide, µg/Nm3 3 400 <5 *** <5 <5 <5 12 <5 <5 <5 <5 Satzman 1 jam NO2 µg/Nm3 Chemiluminescen 4 Oxidant, O 235 <2 *** <2 <2 <2 <2 <2 <2 <2 <2 1 jam 3 t Hydrocarbon, µg/Nm3 5 160 <5 *** <5 <5 <5 <5 <5 <5 <5 <5 GC-FID 3 jam HC* Particulate µg/Nm3 6 150 30 *** 4 13 13 32 3 13 4 13 Dust Analyzer Grab <10mm (PM10) Particulate µg/Nm3 7 65 24 *** 6 2 4 11 27 12 19 4 Dust Analyzer Grab <2.5mm (PM2.5) Total Suspended µg/Nm3 8 230 73 *** 40 74 71 115 31 27 64 33 Dust Analyzer Grab Particulate (TSP) µg/Nm3 <0.1 <0.1 *** <0. 9 Lead, Pb <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 GFAAS Grab 1 52. 10 Noise, L ** dB - 45.8 *** 73.7 71.1 58.7 58.1 58.8 56.6 59.7 Noise Levelmeter Grab avg 5 Note : * Government Regulation No. 41 Year 1999 regarding Air Pollution Control ** MoE Decree No 48 Year 1996
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Besides the climate components, the pollutants concentration will depend on the emission rate of each pollutant from ongoing activities, residence time and rise level of each pollutant. Pollutant gases such as SO2, NO2, CO, O3 and HC will rise to the higher atmosphere with varying residence time (SO2: 2-8 days, NO2: 0.5-3 days, CO:
30-90 days, O3: 1-3 months, and HC: 0.5 - 2 years). Particulates pollutants will rise to lower level of the atmosfer with residence time of a few days to several weeks. With the different residence times of each pollutant, the measured concentration of pollutants during each sampling will vary.
Measured concentrations of each air quality parameter during both the dry season and wet season are shown in Figure II-13. From the graph in Figure II-13, it is shown that the tendency of SO2, NO2 and O3 concentrations were lower in the wet season. The wet season enabled the occurrence of rain-out causing measured concentrations to be lower. Hydrocarbon (HC) and Pb concentrations in the wet season and dry season were not detected (below the instrument detection limit).
Concentrations of particulate parameters (TSP, PM10 and PM2.5) were monitored relatively higher in the wet season. In this case, seasonal variations toward concentrations of TSP, PM10 and PM2.5 did not appear to be significant, since particulate concentrations were greatly affected by ongoing local activities during sampling. Besides, the percentage of calm winds in the month of August (dry season) was recorded as lower than in October (wet season). With increasing calm winds in the wet season, the longer TSP, PM10 and PM2.5 will remain in the ambient air (as they are not well-dispersed). The same condition could also occur with CO, due to CO is a pollutant with greatest emission sources compared with other pollutant gases, in relate to imperfect fuel combustion system. Combustion can occur in various activities either stationary sources or mobile sources (transportation).
Figure II-13 shows the comparison of air parameter concentrations at offshore and onshore locations. From this figure, it is indicated that concentrations of Ozone (O3) tend to be higher at offshore than onshore location. This is among others due to the deposition speed of O3 , which on seawater surface tends to be lower than on land (Pleijel et. al., 2013). For other parameters, no significant differences in concentration values between offshore and onshore locations were identified. The values of Pb concentrations were not detected throughout all observation locations or in other words <0,1 µg/Nm3.
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0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1.000 35.000 500
900 900 30.000 30.000 800 400 400
Onshore ) 3
) Offshore 25.000
3 700 ) Onshore Onshore 3 Offshore Offshore
600 g/Nm 300 g/Nm
g/Nm 20.000 (µ µ (µ 2
2 500 15.000 400 355 200
300 255 10.000
200 154 Konsentrasi CO ( 100 130 127 Konsentrasi NO Konsentrasi SO 5.000 86 77 60 66 67 1.490 1.370 1.140 1.490 1.260 1.370 100 44 1.140 1.140 1.140 12 20 34 20 20 20 20 1.030 916 1.150 1.150 1.140 1.140 5 5 11 20 2 573 687 573 573 5 5 5 6 5 5 6 5 5 5 5 5 5 4 5 0 0 0 AQN-1 AQN-2 AQN-4 AQN-6 AQN-7 AQN-8 AQN-9 AQN-10 AQN-11 AQN-12 AQN-1 AQN-2 AQN-4 AQN-6 AQN-7 AQN-8 AQN-9 AQN-10 AQN-11 AQN-12 AQN-1 AQN-2 AQN-4 AQN-6 AQN-7 AQN-8 AQN-9 AQN-10 AQN-11 AQN-12 Lokasi Pengambilan Sampel Lokasi Pengambilan Sampel Lokasi Pengambilan Sampel
SO2 Musim Kemarau SO2 Musim Hujan PP 41/1999 (1 jam) CO Musim Kemarau CO Musim Hujan PP 41/1999 (1 jam) NO2 Musim Kemarau NO2 Musim Hujan PP 41/1999 (1 jam)
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 275 175 300 160 235 150 225 250 ) ) 3 3 235 Onshore 125 )
3 Offshore g/Nm
175 g/Nm 200 µ µ Onshore Offshore Onshore Offshore
g/Nm 100 (µ
3 125 150 150 75
75 100 50 Konsentrasi HC ( 25 20 65 14 10 Konsentrasi O 25 50 25 ( Partikulat Konsentrasi 32 17 26 1 2 1 1 2 1 2 1 2 1 2 2 2 2 2 13 19 19 19 10 20 9 22 11 16 24 13 19 17 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 12 13 15 11 8 8 9 9 9 3 11 AQN-1 AQN-2 AQN-4 AQN-6 AQN-7 AQN-8 AQN-9 AQN-10 AQN-11 AQN-12 5 2 -25 0 0 AQN-1 AQN-2 AQN-4 AQN-6 AQN-7 AQN-8 AQN-9 AQN-10 AQN-11 AQN-12 AQN-1 AQN-2 AQN-4 AQN-6 AQN-7 AQN-8 AQN-9 AQN-10 AQN-11 AQN-12 Lokasi Pengambilan Sampel Lokasi Pengambilan Sampel Lokasi Pengambilan Sampel TSP Musim Kemarau PM10 Musim Kemarau PM2,5 Musim Kemarau O3 Musim Kemarau O3 Musim Hujan PP 41/1999 (1 jam) HC Musim Kemarau HC Musim Hujan PP 41/1999 (3 jam) PP 41/1999 TSP - 24 jam PP 41/1999 PM10 - 24 jam PP 41/1999 PM2,5 - 24 jam
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 2,5
2,0 2 ) Onshore Offshore 3 g/Nm µ 1,5 Onshore Offshore
1,0
Konsentrasi ( Pb Konsentrasi 0,5
0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,0 AQN-1 AQN-2 AQN-4 AQN-6 AQN-7 AQN-8 AQN-9 AQN-10 AQN-11 AQN-12 Lokasi Pengambilan Sampel
Pb Musim Kemarau Pb Musim Hujan PP 41/1999 Pb - 24 jam
Figure II-13 Environmental Baseline of Ambient Air Quality in Tangguh LNG
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2.1.3 Noise
Noise level data was obtained from onshore measurement (AQN-1, AQN-2, AQN-4, AQN-6, AQN-7 and AQN-8) and offshore (AQN-9, AQN-10, AQN-11 and AQN-12). Onshore sampling was differentiated into two locations, i.e. inside the Tangguh LNG area and nearest settlements outside the Tangguh LNG area boundary. Noise level measurements were conducted in two seasons, i.e the dry season and wet season. Noise level in the dry season was measured from August 5th to August 16th, 2012, while measurement in the wet season was conducted on October 27th and October 28th, 2012.
Noise level measurement in the Tangguh LNG was conducted using sound level meter equipped with measurement feature of Leq (equivalent energy level). Noise level was measured every 5 seconds over 10 minutes for each measurement and maximum four times measurement during daytime. The measurements were performed to obtain the equivalent noise level (Leq) for 16 hours through calculations based on MoE Decree (KepMen LH) No. 48 Year 1996 regarding Noise
Level Quality Standard and Average Noise Level (Lavg) through arithmetic mean calculation. However, due to safety reasons, measurement of noise level at the Tangguh LNG area was only made three times during daytime at 12 selected locations. Then, calculation results were compared with the quality standard for noise level in accordance to the location classification as stated in MoE Decree (KepMen LH) No. 48 Year 1996.
Locations of noise level measurement and sampling status in the dry season and wet season are shown in Map II-2 and Table II-5. Noise level as mean value of measurement in the daytime period is shown in Figure II-14. Detail data is presented in Appendix II.1 and Appendix II.2 Environmental Baseline Data.
Based on Figure II-14, the average noise level at offshore (41.1 dBA – 54.2 dBA) and onshore (55.3 dBA – 62.8 dBA) in the dry season overall meet the noise level quality standard. However, during the wet season, onshore noise level (45.8 dBA – 73.7 dBA) are quite fluctuative than offshore noise level (56,6 dBA – 59,7 dBA) that indicate more stable values. Offshore noise values in the wet season were observed slightly higher than those in the dry season, this is possibly due to the influence of noise caused by wind and sea waves that are higher during the wet season.
The tendency for higher noise level in the wet season compared with the dry season is due to rising air humidity and air temperature. Both physical elements of atmosphere can cause lower air density, so that will affect on reducing noise attenuation ability due to the atmospheric condition (Ahrens, 1994).
Equivalent noise level in daytime during the wet season is shown in Figure II-15 that indicates similar tendency on average noise level in daytime during the wet season. Onshore average noise level varied between 41.1 dB and 73.3 dB. Offshore Average noise level varied between 58.2 dB and 60.6 dB.
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The noise level in two measurement locations onshore during the wet season exceeds noise level standard both for settlements area (Tanah Merah Baru) and for the Tangguh LNG area (industry). Based on records of noise level sampling at measurement point of AQN-7 (Tanah Merah Baru settlements), the noise level was affected by natural conditions (wind, animals, and so forth), as well as by human activities, among others due to mower’s noise during measurements of the noise level.
Noise level measurements adjacent to LNG Train 1 and 2, indicated value of 73.7 dBA. The noise level value at AQN-4 (open area proposed as a jetty for condensate tankers and LNG tankers) exceeded the quality standard for industrial area, i.e. 70 dBA. However, according to MoE Decree No. 48 Year 1996 the specified value of noise level quality standard has a tolerance of +3 dBA so that, noise level at AQN-04 can be considered to meet noise level quality standard.
Onshore Offshore
Figure II-14 Average Noise Level at Tangguh LNG
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Onshore Offshore
Figure II-15 Equivalent Noise Level at Daytime during Wet Season at Tangguh LNG
2.1.4 Hydrology
There are two principal watersheds (DAS) involved in the project site, namely DAS Manggosa and DAS Saengga. The Manggosa River is located on the eastern boundary of the Tangguh LNG site, while the Saengga River is located on the western boundary of the Tangguh LNG site. DAS Saengga is much larger than the DAS Manggosa.
Between the two large rivers, several creeks generally flow directly to the north coast estuaries. Thus, drainage from the Tangguh LNG location is divided into three flow directions: • To the north through several creeks, flowing directly to the coast; • To the west to Saengga River; • To the east to Manggosa River.
The creeks found in the Tangguh LNG area could be considered ephermal where during extreme dry season, the creeks can dry up.
From Figure II-16 it is estimated that around 449.6 ha of drainage area drains to the Manggosa River to the East and around 1,084.5 ha of the location drains to Saengga River to the West while drainage for the remaining areas lead to the coast in the north.
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Figure II-16 Rivers and Creeks in Tangguh LNG Area
Figure II-17 Boundaries of Watersheds (DAS) for Rivers around the Tangguh LNG Area
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The Manggosa River is only navigable around its estuary due to the density of Nipa Palm and other riparian vegetation. The Saengga River can be navigated further. Kampong Saengga, Onar and Tanah Merah Baru can be accessed from Bintuni Bay through the Saengga River. However, large boats can only pass river shoals during high tide. Both the Manggosa and Saengga Rivers are strongly influenced by tidal.
Figure II-18 Dominant Riparian Vegetation (Nipa Palm and Mangrove)
Saengga River is the largest river adjacent to the Tangguh LNG area where the main channel of the river is located approximately 1.5 to 2.0 km to the west of the Tangguh LNG boundary.
The slope of the Saengga River bed at downstream is relatively low, resulting in meandering mainly approaching the coast. The river depth varies between 4 to 5 m at the deepest point during high tide. The river width also varies reaching 80 m at the estuary.
The main boundaries of watersheds and creeks in the Tangguh LNG area are shown in Figure II-19. There are seasonal creeks/streams (ephemeral) in the Tangguh LNG area, in which several natural streams meet. The creeks are generally unnamed. For the purpose of the study, the streams watersheds area are given the code ‘S’ and a number. The sequence of numbering follows the watershed area measurement from the largest area (S1) to the smallest (S5).
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Figure II-19 Flow Boundaries of Rivers and Creeks in the Tangguh LNG Area
Geomorphology of the main rivers and creeks watersheds in the Tangguh LNG area is shown in Figure II-19.
Table II-7 Characteristics of Principal Watersheds and Creeks around the the Tangguh LNG Expension Project Site
Average Maximum Area Name of Watershed Elevation (ha) River Slope Length Width Depth Elevation (%) (km) (m) (m) (m) (m) S1 1,482 37 8.615 6.5 0.4 21 100 S2 660 33 6.640 4.0 0.3 20 69 S3 598 31 4.829 3.8 0.3 17 72 S4 96 26 1.601 1.3 0.1 24 67 S5 53 23 1.316 0.9 0.1 20 58 Manggosa 5,070 24 18.703 13.6 0.6 17 310 Saengga Upstream 13,989 31 27.485 25.0 0.9 36 399 Saengga Midstream 8,057 23 20.003 18.0 0.8 17 225 Saengga Downstream 12,777 21 38.145 23.7 0.9 15 340 Source : Processed from the result of DEM automatic delineation using the SWAT (Soil and Water Assessment Tools) program from the US Department of Agriculture
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Figure II-20 Contour Map
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2.1.5 Hydrogeology and Groundwater Quality
There are two aspects of hydrogeology included in the scope of the EIA for Tangguh LNG Expansion Project as described in the Terms of Reference: a. Baseline associated with potential alternative use of groundwater; and b. Baseline on quality of shallow groundwater/unconfined aquifer.
Groundwater Basin According to Law No 7 Year 2004 regarding Water Resources, Article 12 paragraph (2) stipulates that groundwater management is based on Groundwater Basin (CAT, Cekungan Air Tanah), which Groundwater basins are established by Presidential Decree (Article 13 paragraph (1)). Furthermore, in Government Regulation No 43 Year 2008 regarding Groundwater, Article 4 stipulates that groundwater management is based on Goundwater Basin conducted on the basis of groundwater management policies and strategies.
Referring to Law No 7 Year 2004 and Government Regulation No. 43 Year 2008, in the discussion of hydrogeology environmental baseline, it is essential to relate the location of the Tangguh LNG Expansion Project to a Groundwater Basin. Based on Presidential Decree No. 26 Year 2011 regarding the Establishment of Groundwater Basin (CAT), Appendix 1, List of Groundwater Basins in Indonesia states that the location of the Tangguh LNG Expansion Project is part of the CAT Kanoka-Babo with coordinate boundaries 1320 43’ 28.2” – 1340 07’ 55.31” E and 020 13’ 36.77” – 040 07’22.12” S. The CAT Kanoka-Babo has an area of 16,870 km2 approximately and encompasses the three regencies of Fakfak, Teluk Bintuni and Teluk Wondama.
Groundwater Basin overview of Kanoka-Babo can be seen in the Groundwater Map Sheets V Morotai and VII Ambon, published by the Directorate of Environmental Geology and Mining Region, 2005 (Map II-3). There is very limited data available for the CAT-Babo Kanoka and this is restricted to the immediate area to the Tangguh LNG where some investigations were undertaken over the period of 2000- 2006. Threre is practically no information on potential Groundwater Basin that illustrates the geometric dimensions, aquifers distribution and aquifers characteristics and the total availability and quality of groundwater. However, theoretical estimates of groundwater flow rate for CAT Kanoka-Babo ranging
between Q1 11,267 Mm3/year and Q2 558 Mm3/year.
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Source: Groundwater Basin Map of Indonesia Sheet V Morotai and VII Ambon, Directorate of Geological and Mining Area Environmental Development, 2005 Map II-3 Location of Kanoka-Babo Groundwater Basin and Sub Basin of the Tangguh LNG Facility
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Lithology and Presence of Groundwater Aquifer The regional geological condition of the Bintuni Bay area are shown on Map II-4 Geology of Bintuni Bay Area (Robinson et al., 1990 op.cit. LAPI-ITB, 2004). The Tangguh LNG area is underlain by the Steenkool Formation consists mainly of mudstone. Steenkool Formation outcrops are found in the south-southwest area of the Tangguh LNG, consist mostly of sandstone (TQss, indicated by yellow on the map) and are on an Antiklin structure sloping to the northeast beneath the Tangguh LNG area. This indicates the high possibility of sandstone aquifer beneath the Tangguh LNG area, recharged by rainwater infiltration and surface runoff to the southwest.
Cross section of seismic indicates that sediment layer is commonly flat to depth of around 500 m. The orientation and thickness of the Steenkool Formation in the Bintuni Basin indicate deposition of delta sediment from the south, southeast and east narrowing to the north, northwest and west. Apparently, this could be a dominant effect on the structure and orientation of the Steenkool Formation.
The Steenkool Formation was deposited in a delta area that spread westward during the Miocene to the Pleistocene, and is dominated by clay and deltaic clays and silts with sandy sediment layers and channels (Robinson et al., 1990). The dominant lithology is gray clay, very stiff to hard silty clay, generally with thin layers of silt and sand with thin layers of brown silty sand. A simple version of geological map is shown in Map II-4 confirming that the southwest part of Steenkool Formation subcrop is predominantly sandstone, while the Tangguh LNG area is predominantly mudstone. Several anticlinal characteristics are indicated in the Figure and confirm that sandstones of the Steenkool Formation underlie the Tangguh LNG area and probably become be predominant with increasing depth.
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Map II-5 Geology of Bintuni Bay Area ( Robinson et al., 1990 op.cit. LAPI-ITB, 2004)
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A number of oil and gas exploration wells have been drilled in the area since 1990 penetrating the full thickness of the Steenkool Formation. Their locations and the locations of seismic lines were provided by Tangguh LNG to LAPI-ITB, in 2005 to assist in preliminary evaluation of potential groundwater. The locations of wells and seismic trajectories are shown in Figure II-21. Seismic profiles with slope estimates of layers in the Steenkool Formation are shown in Figure II-22, Figure II-23 and Figure II-24.
The existing data is summarized as follows: a) Seismic For the purpose of this analysis, six selected seismic lines that passing the Tangguh LNG area are as follows: • Southwest–Northeast: NB97-107: 62 km; NB97-108: 32 km; NB97-109: 35.5 km • Northwest-Southeast: NB97-103: 31 km; NB97-104: 28 km; NB97-105: 27.5 km
The seismic data indicated a correlation between the Steenkool Formation and Papua New Guinea Limestone Group and therefore can be used to evaluate the depth and structures of the Steenkool Formation.
The data are seismic lines of 104, 105 and 108 that passing the area adjacent to the proposed testing wells. The assessment was carried out in 2006 as part of potential produced water reinjection study. Further assessment on the slope of the Steenkool Formation sediment at depths of 300 m and 600 m was also carried out as part of this AMDAL study, since the purpose of the seismic survey was to observe the potential gas reservoir which data quality at depth over 500 m from the seismic profile is very limited.
Nonetheless, the seismic data indicated the following: • There is a a potential gas just beneath the location of the Tangguh LNG at depth, associated with strike-slip fault in east-west direction; • There are a number of faults that can be observed at depths over 500 m, which due to dominant structural system in the region, they were possibly as reactivation of left-lateral strike slip fault; • Faults mapped at this depth were possibly of emerging or not emerging on the surface; • Layers in and around the location at depths of less than 500 m are level; • Slope of the layers increase at depth that could be caused by differential compaction.
The general conclusion of the data was that the faults did not emerge on the surface in the Tangguh LNG area.
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Every fault that passes through claystone of the Steenkool Formation, will serve more as groundwater flow obstruction than as groundwater pathways. If the fault acts as pathway, this will cause saline groundwater flow from the lower part of Steenkool Formation to the upper Steenkool Formation. No evidence of upward vertical flow of saline groundwater was observed to a depth of 300 m during slim hole drilling or resistivity survey of ITB. However, the proposed test well for the purpose of investigating salinity to a depth of 400 m and groundwater salinity will be monitored through pumping test for 10 days. If there is a fault boundary, this will be observed from lowering of the groundwater table during the 10 days pumping test, in which the distance to the fault boundary from the test well can be calculated.
Additional interpretation of sediment dip in the Steenkool Formation at depths of 300 m and 600 m are indicated in seismic path 104, 105 and 108 (Figure II-22, Figure II-23 and Figure II-24). Briefly, this is sediment dip measured along the section pathway (it should be noted that this is not the actual sediment dip since the direction of sediment is not known for sure) but believed to represent sediment dip in the Steenkool Formation found beneath the Tangguh LNG location. Sediment dip at depths of 300 m and 600 m are shown in Table II-8.
Table II-8 Sediment Dip at Depths of 300 m and 600 m in Seismic Path Seismic Path Sediment dip at depth 300 m Sediment dip at depth 600 m 104 0.50 0.40 105 0.70 1.20 108 1.40 1.20
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Figure II-21 Well Locations with Lithologic Logs and Seismic Path
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Figure II-22 Seismic Profile for Path 104 with Estimated Sediment Dip in Steenkool Formation at Depths of 300m and 600m beneath Tangguh LNG
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Figure II-23 Seismic Profile for Path 105 with Estimated Dip of Steenkool Layer at Depths of 300m and 600m beneath Tangguh LNG
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Figure II-24 Seismic Profile for Path 108 with Estimated Dip in Steenkool Layer at Depths 300m and 600m beneath Tangguh LNG
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b) Lithology Log Vertical and lateral rock distribution are interpreted from downhole geophysical logs and description of lithology from drill cuttings. Onshore and offshore borehole wells used in the assessment are as follows: Onshore: Kasuri-1, Aroba-1, Terie-1, South Jarua-1, and South Monie-1 Offshore: Vorwata-1, Vorwata-2, Vorwata-3, Vorwata-4, Vorwata-5, Vorwata-6, Vorwata-7, Vorwata-8, Vorwata-9, Vorwata-10, Vorwata-11, Wiriagar Deep-1 , Wiriagar Deep-2-3 Wiriagar Deep, Wiriagar Deep-4, Wiriagar Deep-6, Wiriagar Deep-7, Ofaweri-1, Roabiba-1, Nambumbi-1, Sakauni-1, WOS-1, and Kalitami-1X Onshore North: Sebyar-1 and Aum-1.
Figure II-25 Reconstruction of Cross Section of Oil Company and Well TW1- TW2
Figure II-25 shows cross section line extending from TW1-TW 2 through exploration well Roabiba-1 to exploration well Nambumbi-1.
In the Tangguh LNG area it is estimated that bottom depth of the Steenkool Formation is approximately 1,500 m. Initial drilling to a depth of 153 m (TW1 and TW2) conducted in 1999/2000, and supported by geology map interpretation confirmed the existence of sandstone layer between layers of relatively impermeable claystone. After cross section was made in 2007, another well was drilled near the shore (Slimhole Drillhole 1, SHD1) between TW1-TW22 and Roabiba-1, identifying the existence of sandstone aquifer to a depth of 310 m. This indicated that frequency and depth of sandstone may extend to a depth of 300 m.
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Results of geological study of the Tangguh LNG area (Baynes Geology, 2006) indicated that the Bintuni Basin was influenced by echelon faults in the Northwest – Southwest direction and folds that were generally parallel with the faults. Slope of sediment to a depth of 500 m from the surface was relatively level (less than 0.50).
It is unlikely that faults will extend to the surface around the Tangguh LNG area (Baynes Geology, 2006), although the tendency of faults in the East-West direction as shown in the geology map some 5 km to the South (Robinson et al, 1990) are groundwater aquifers flowing through granular pore space.
Numeric modeling indicates that Steenkool Formation recharge is approximately 3% from rainfall.
The discharge area system in the Tangguh LNG area is not yet known, but it is likely that the subsurface flow heads to Bintuni Bay through sandstone subcrop from Anticlinal Highs or fault zones. The flow area might be located north of the Tangguh LNG area under Bintuni Bay or further to the west in the Banda Sea. c) Groundwater Salinity No data is available on shallow groundwater salinity in the Steenkool Formation to a depth of 30 m other than as shown in the hydrogeology cross section (Figure II-27) and also interpretation of groundwater salinity to a depth of 300 m based on geophysical logging in slim hole drilling SHD-1. Initial assessment made showed that ground water salinity to a depth of 600 m, which is the bottom part of numeric modeling, was less than 1,000 mg/L. Numeric modeling described in Chapter III indicated that salinity is based on groundwater flow and water balance, and this is shown in the cross section and map. Numeric modeling used the assumption that the meeting point of fresh water-saline water in the lower part of the Steenkool Formation was located some 2 km offshore.
Potential Groundwater Potential groundwater in the Tangguh LNG area may be evaluated from the results of several surveys that were performed, drilling, geophysical log and geo-electrical survey made during 2000 through 2006, including survey toward community well installations in the Steenkool Formation in Tanah Merah and Saengga.
In and around the Tangguh LNG area a total of 11 groundwater wells have been drilled with depths ranging between 90 m to 300 m (Table II-9). The drilling locations are shown in Figure II-26, except for two bore holes in Onar Baru and Onar Lama (WWOL-1 and WWOB-1) at distance of more than 12 km to the West.
Drilling and testing of TW1 and TW2 wells were done from 1999 through 2000. TW1 was abandoned at depth 132.5 m due to drilling problems and loss of equipment into the well. Then the bore well was replaced by TW2 at distance of about 82 m from TW1. However the filter in TW2 bore well was not installed at the proper depth and the bore well was eventually abandoned after fine sand continued to enter the bore well during pumping test. However, useful data was acquired on aquifer distribution, aquifer parameter and groundwater quality.
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Bore wells made in Saengga, Tanah Merah Baru, Onar Baru and Onar Lama in 2005 to 2006 were for the purpose of providing water supply to the four villages as part of the community development program conducted by the Tangguh LNG.
In 2006, further study was made of aquifer distribution in the Steenkool Formation beneath the Tangguh LNG area at depths of between 150 and 310 m with small diameter drilling (Slim hole SHD-1). Although casing and filter were not installed in the bore well, useful data was obtained on sandstone distribution and estimated water quality from the well geophysical log.
Results of drilling in TW1 and TW2 indicated the existence of confined aquifer in the Steenkool Formation to a depth of 150 m. Piezometrik groundwater table reached a depth of 2.5 m below the surface. Bore wells TW1 and TW2 are located centrally between community well in Tanah Merah Baru/Saengga and small- diameter well (Slim Hole SHD-1) at depth 310 m.
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Figure II-26 Locations of Resistivity Survey
Table II-9 Construction of Groundwater Wells and Pumping Test Results and Location of VES in Path A, B and C
Date of Total Pumping Test Depth of Salinity Drill Number Drilling/ Depth Note Filter (m) Discharge Duration Withdraw (mg/L) TDS Construction (m) (L/s) (jam) (m) TW1 Jan 2000 153 - - - - Sand 136 - 151 m. - Abandoned, drill shaft stuck in hole TW2 Jan 2000 153 87 - 93 1,4 6,7 16,5 488 98,8 - Sand 135 - 150 m. 101,8 Covered by mud during construction. 104 - 116 WWS-3 Nov - Dec 135 Kampong Saengga 2005 98 - 110 2,5 24 5,4 325 WWS-4 Nov 2005 129 101 - 122 2,6 24 5,8 326 Kampong Saengga WWTMB - 1 Jan - Feb 2006 151 98 - 110 Kampong Tanah Merah Baru 122 - 125 3,2 24 12,7 321 WWTMB - 2a Jan - Mar 2006 150 106 - 118 Abandoned, unable to be built without sand 121 - 124 - - - - WWTMB - 2b Apr - May 135 Abandoned, drill string separated in hole 2006 - - - - - WWTMB - 2c Aug 2006 133 Abandoned, unable to be completed due to swelling - - - - - clay WWOB - 1 Feb - Mar 2006 90 71 - 83,3 2,9 24 18,3 257 Kampong Onar Baru WWOL - 1 Jun - Jul 2006 90 40 - 45,2 2,9 24 7,4 325 Kampong Onar Lama SHD - 1 Dec 2006 - Jan 310 Muddy sand , 266 - 275 and 283,5 and 293,5 2007 - - - - -
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Interpretation of geophysical log for wells TW1, TW2, SHD1 and community wells in Tanah Merah Baru and Saengga (ERM, 2007), identified several indicator layers with profiles enabling correlation of aquifer from Saengga to Tanah Merah Baru through well TW1/TW2 and SHD1 in the Tangguh LNG area (Figure II-27). This correlation confirmed that the sandstone layer at SHD1 became thicker and more frequently found below depth of 250 m and separated from the aquifer utilized in Saengga and Tanah Merah Baru by a relatively thick impermeable claystone horizon. Based on the geological interpretation, there is good potential for sandstone layer to be thicker and coarser at depths below 300 m based on regional geologic distribution of sandstone in the Steenkool Formation.
Geoelectrical resistivity survey was conducted in July-August 2004, along four inter- connected paths in the Tangguh LNG area. Survey was done using the Vertical Electrical Soundings (VES) method, with Wenner configuration and electrode separation until 310 m. Results of geoelectric resistivity survey along AB, were interpreted with re-calibration of bore well log TW1, TW2, WWTMB-1 and SHD-1 (Figure II-28). Estimated resistivity of VES survey data of 2004 may be correlated with lithology at SHD -1. Re-interpretation indicated that in general sand layer below a depth 266 m at bore well SHD-1 extended laterally at least 3 km to the southwest, and there was correlation between interpretation of VES and adjacent drilling log.
Resistivity survey and hydrogeological cross section of downhole electric and gamma logs, indicated an absence of significant vertical shift in the Steenkool Formation to a depth of 300 m. Hydrogeological cross section indicated 0.8° dip in the Steenkool Formation at depth of approximately 100 m however it should be noted that the seismic cross section path used to calculate sediment dip was not perpendicular to the true dip of sediment. This was in line with sediment dip at depths 300 m and 600 m measured from seismic profile.
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Figure II-27 Hydrologic Profile and Aquifer Correlation for Saengga – Tanah Merah Baru – Tangguh LNG (2007)
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Figure II-28 Aquifer Correlation
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Interpretation of geophysical resistivity log of bore well SHD-1, indicated that groundwater at depth 150 - 300 m below the surface had salinity of less than 500 mg/L. Results of lithology log (from drill cuttings) and geophysical resistivity log at bore well SHD-1 indicated the presence of ten aquifer zones between the surface to a depth of 150 m with total thickness of 83 m. Below 150 m until total depth of 310 m, groundwater aquifers were found at depths between 266 m - 275 m and 283.5 m – 293.5 m, total thickness of the two aquifers were 19 m.
Hydraulic Characteristics of Groundwater Aquifer In the period from 1997 to 2005 Calamarine operated a base camp near Tanah Merah Lama in the Tangguh LNG area and relied on a production well 26 m deep to provide water needs of the camp. During that period, the well operated satisfactory to produce good quality groundwater for drinking water, with no indication of increased salinity despite the relative proximity from the waters of Bintuni Bay.
Exploration drilling for groundwater supply for the Tangguh LNG Project was made between 1999 to 2000, aside from the failure of the previous well bore TW1 and TW2, much information was obtained on sand dispersion to a depth of 150 m, groundwater table, groundwater salinity and aquifer parameters.
In 2006, community wells were built in Tanah Merah Baru and Saengga with respective depths of 153 m and 135 m in the Steenkool Formation, and additional data was obtained on groundwater table, groundwater quality and aquifer parameters. Sandy rock layers found in community wells may be connected to sandy rock layer at intersection of well TW1/TW2 and SHD1.
Hydraulic characteristics of groundwater aquifer in the Tangguh LNG Project area could be obtained from pumping test results in the TW2 well and community wells. Pumping test at bore well TW2 was performed for a short period, but was unsatisfactory as fine sand continued to enter the filter. Maximum groundwater discharge at bore well TW2 during the short pumping test before finally being abandoned was between 10 to 14 L/second, with drop in groundwater table of 38 to 49 m.
Head measurement from +2.55 m MSL in bore well TW2 was considered consistent with recharge zone at higher ground surface elevation to the South and head increased with increasing depth. It was concluded that with increasing depth, pressure would increase with potential artesian flow in area with low ground surface elevation.
Water surface depth measured in two community wells in Saengga (to depth of 135 m) ranged between 21.6 m and 20.7 m below ground surface, equivalent to elevation of +2.2 to 3.1 m MSL. Groundwater surface of community well in Tanah Merah was 34.52 m below ground surface, equivalent to around -0.2 m MSL, however due to its proximity to original community well in Tanah Merah Baru that was eventually abandoned, the groundwater surface experienced change with the lower groundwater surface and may be disregarded.
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It should be noted that despite the five-year measurement interval, hydrostatic heads are sufficiently representative for confined aquifer to depth of 150 m in the Steenkool Formation in which the aquifers may be correlated between Saengga, Tanah Merah and well TW1/TW2. Hydrostatic pressure increased with increasing depth and with increasing distance from shore in Bintuni Bay. Apparently, the shallowest part near the surface of the Steenkool Formation was unconfined aquifer, and depended on seasonal re-charge, and higher groundwater table in relation to topography and drainage. This indicated limited hydraulic correlation between the surface of the Steenkool Formation (unconfined) and Steenkool Formation at greater depths (confined), which indicated that main recharge to the Steenkool Formation occurred in sandstone outcrops to the Southwest.
Estimated transmissivity and hydraulic conductivity, taken from pumping test data, are shown in Table II-10. Average hydraulic conductivity from all pumping test results was 4.4 m/day.
Groundwater Conservation Zone Map The Groundwater Conservation Zone Map for the Tangguh LNG region and explanation have been prepared in accordance with Government Regulation No. 43 Year 2008 concerning Groundwater. According to Article 24 Paragraph 3 of the regulation (Establishment of Conservation Zone), utilization of groundwater from aquifer needs to be evaluated to determine safe, vulnerable, critical, and damaged groundwater zones .
Two Groundwater Conservation Zone Maps were made for the AMDAL study and the following explanation is used to determine the limits of groundwater conservation zone. • Safe – groundwater source not excessively extracted or not included as vulnerable to be excessively extracted, and the groundwater quality is not affected by impact or not likely to be impacted by human activities and/or influences. • Vulnerable – sustainable yields are estimated to be low, with current groundwater extraction approaching or likely exceeding sustainable yields capacity of the aquifer, or groundwater quality likely to be affected by impact of activities and/or indirect influences of human activities. • Critical – groundwater extraction exceeds sustainable yields and/or groundwater quality affected by impact of activities and/or impacted by activities and/or indirect influence of human activities. Improved groundwater quality and/or groundwater source recovery is possible if groundwater resources are managed in better manner. • Damaged – groundwater resources are in threatened condition due to groundwater extraction far exceeding capacity of sustainable yields and/or groundwater quality is significantly affected by impact of human activities. Recovery of groundwater resource able to be utilized or improvement of groundwater quality is already quite difficult.
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The Tangguh LNG region encompasses a small area (approximately 32 km2) in a sub-basin (approximate area 750 km2) as part of Groundwater Basin (CAT) Kanoka- Babo (16,870 km2) as shown in Map II-3.
Preparation of the Groundwater Conservation Zone Map should be viewed in the context of the Kanoka-Babo Groundwater Basin area, by conceptual hydrogeological modelling (Figure II-29), as the basis of numerical modeling with wider limits than the Tangguh LNG area.
The hydrogeological conceptual model indicates that the Tangguh LNG area consists of several layers of aquifer system, in which the aquifer in the Steenkool Formation to depth of 600 m has potential for groundwater resource with suitable quality to meet groundwater supply needs of Tangguh LNG. The Groundwater Conservation Zone Map was made on the basis of conceptual modeling and other data described in the environmental baseline section of the ANDAL document. The first Groundwater Conservation Zone Map was for aquifers from the surface to depth of 150 m below the ground surface. The second Groundwater Conservation Zone Map is for aquifers located in the lower part of the Steenkool Formation at depths from 150 m to 600 m below the ground surface.
The two Groundwater Conservation Zone Maps indicate groundwater sources at Tangguh LNG that can be utilized and are also vulnerable, to a depth of 150 m below ground surface, and which have been utilized by the population of Kampong Tanah Merah Baru and Saengga and previously used to support various surveys made by the project before the first AMDAL was approved in 2002. This zone is shown in Map II-5 Groundwater Conservation Zone 1: Shallow Aquifer in the Steenkool Formation between 0 m bmt and 150 m bmt in the Tangguh LNG facility. The second Zone lies at depth of between 150 m and 600 m below ground surface, which is the target aquifer being studied as a potential source of groundwater for Tangguh LNG and shown in Map II-6 Groundwater Conservation Zone 2: Confined Aquifer in the Steenkool Formation between 150 m and 600 m bmt in the Tangguh LNG Facility.
The Baynes Geological Report of 2006 was used as reference in assessing the possibility of faults existing in the Tangguh LNG location.
Bintuni Basin sediments, such as the Steenkool Formation dating to the Late Miocene – Plistocene found at the Tangguh LNG location, is the outcome of erosion of the Lengguru fold in the east and Tamru highlands in the north. The Steenkool Formation is of greatest thickness near the Lengguru fold.
The structure of the upper portion of the Kais Formation dating to the Miocene period, near the Wiriagar gas field in the Bintuni Basin illustrates compression in the northeast-southwest direction dating to the Pliocene produced faults en-echelon, small displacement left-lateral strike-slip with similar direction of orientation, and folds in the northwest- southeast direction. The compression also reactivated left- lateral strike-slip faults dating to the Oligocene in the east-west direction. The faults indicate maximum displacement of 200 m after Miocene Displacement.
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Fault displacement in the northeast-southwest direction is smaller than the one occurring in the east-west direction. Folded sediments from the Pliocene period are covered by level sediments dating to the Pleistocene indicating that tectonic deformation along the northwest-southeast fold in the Wiriagar area of Bintuni Basin halted during the Pleistocene period. From interpretation, it may be concluded that every contemporary fault in the Bintuni Basin and in even wider areas of the Bird’s Head, are characterized by small-displacement, left-lateral motion on east-west trending vertical strike-slip.
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Table II-10 Hydraulic Parameters of Pumping Test Pumping Final Specific Calculated Transmissivity (m2/day) Transmissivity Hydraulic Drill Filter Depth discharge drawdown Capacity Value applied Conductivity Number (m) (L/s) (L/s) (m2/day) Pumping Recovery Specific Capacity (m2/day) (m/day) 87 - 93 TW2 98,8 - 101,8 1,4 16,5 26 - - 32 32 1,5 104 - 116 WWS-1 98 - 110 2,5 5,4 40 98 50 49 50 4,2 WWS-2 101 - 122 2,6 5,8 39 54 29 48 51 2,4 98 - 110 WWTMB - 1 3,2 12,7 22 61 45 27 53 3,5 122 - 125 WWOB - 1 71 - 83,3 2,9 18,3 14 16 14 17 15 1,5 WWOL - 1 40 - 45,2 2,9 7,4 34 100 324 41 70 13,5 Source: Pumping Test Results
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Figure II-29 Illustration of Regional Hydrogeology Conceptual Model
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Map II-5 Groundwater Conservation Zone 1: Shallow Aquifer in the Steenkool Formation between 0 m and 150 m bmt in LNG Tangguh Facility Groundwater conservation zone (groundwater recharge area) found in and located near the Tangguh LNG is divided into three groups, namely: 1. Unconfined aquifer associated with alluvial deposit along rivers and streams originating from and passing the Tangguh LNG facility, was refilled by rivers and pools, and also by direct rainwater infiltration with discharge locations in areas of lower elevation and also to the sea; 2. Shallow aquifers found at the upper 30 m of the Steenkool Formation, are recharged by rainwater infiltration along the surface outcrops and discharge locations in areas with lower elevation; and 3. Confined and semi-confined aquifers found in the upper part of the Steenkool Formation, are recharged through areas where sandstone outcrops at higher elevation to the south and southwest of the Tangguh LNG location are found and also recharged by flow of water from the aquifer above it. Outflow locations are found in Bintuni Bay.
Safe Zone – unidentified.
Vulnerable Zone – four vulnerable zones of groundwater utilization consist of : 1. Facility area located on alluvial deposit, 2. Facility area on soils dominated by clays of the upper part of the Steenkool Formation, which are shallow aquifers and/or sufficiently large semi-confined aquifers, 3. Groundwater on lower part and downstream (down gradient) of the organic waste disposal site, inerts landfill and organic landfills, with potential for pollution. 4. Sandstone aquifer in the upper part of the Steenkool Formation, from the surface to a depth of 150 m below the ground surface with potential as a source of groundwater for the local community.
Critical Zone – unidentified.
Damaged Zone – unidentified.
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Map II-6 Groundwater Conservation Zone 1: Shallow Aquifer in the Steenkool Formation between 0 m and 150 m bmt in LNG Tangguh Facility
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Map II-6 Groundwater Conservation Zone 2: Confined Aquifer in the Steenkool Formation between 150 m and 600 m bmt in LNG Tangguh Facility
Due to the hydrogeological condition in an overall area larger than Tangguh LNG area, there are no recharge locations for confined aquifer zone in Map 2 Groundwater Conservation Zone in the Tangguh LNG location. Groundwater in confined aquifer is estimated to flow beneath the Tangguh LNG location from the recharge areas in the south and southwest to the discharge area in the north and/or northwest of the LNG facility. This mechanism is shown by inflow along the south side of the Tangguh LNG facility.
Safe Zone – unidentified.
Vulnerable Zone – exploitation of groundwater resources in the lower part of the Steenkool Formation aquifer if not well-managed and monitored has the potential to cause lowering of the groundwater table in community wells, soil subsidence, and seawater intrusion
Critical Zone – unidentified.
Damaged Zone – unidentified.
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Map II-7 Groundwater Conservation Zone 2: Confined Aquifer in the Steenkool Formation between 150 m and 600 m bmt in LNG Tangguh Facility
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Groundwater Quality Evaluation of groundwater quality analysis was made to assess groundwater quality, with regard to the option to use groundwater in place of seawater desalination.
Groundwater samples obtained from TW2 well in July and August 2000 (Calmarine Indonesia, 2001) indicated that groundwater quality was dominated by sodium and bicarbonate, that together constitute nearly 90% of weight (in miliequivalent) as principal ion.
Groundwater analysis of community wells indicated similar chemical parameters as those of groundwater from TW2 well, with slightly lower salinity of TDS 163-296 mg/L in community wells compared with TDS 353-387 mg/L in well TW2. Analysis of fluoride parameter was also conducted on groundwater originating from bore wells, in which the value was still below the threshold limit of Class I water quality standard according to Regional Regulation No. 82 of 2001 concerning Water Quality Management and Water Pollution Control. Groundwater is generally alkaline with pH ranging from 7.9 to 8.4, except for well WWOL-1 in which groundwater quality is influenced by the presence of marshes in the absorption area with pH anomaly 6.9.
Groundwater quality in Tanah Merah and Saengga met Class I water quality standard specified in Government of Indonesia Regulation No. 82 Year 2001. Monitoring of groundwater quality in March and August 2012 confirmed that groundwater quality in Saengga was very good (TDS 89-179 mg/L) or one half of the groundwater salinity of Tanah Merah (TDS 344-381 mg/L). The difference in salinity between wet season and dry season indicated there was significant recharge, however it is not yet ascertained at this stage whether the recharge originated from sandstone outcrops in the Steenkool Formation or was local in nature.
Unconfined Aquifer Community Wells Groundwater quality samples were taken from community wells in kampong Saengga and Tanah Merah at the time of the environmental baseline survey for the AMDAL study in 2002 as shown in Table II-11.
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Table II-11 Groundwater Sampling – Field Survey for AMDAL 2002 Sampling Coordinates Dry Wet Location Location season season Code South East GW-100 Simuri (Saengga) Base Camp – old 20 27’ 1330 6’ √ √ well 41.22” 17.76” GW-105 Simuri (Saengga) - new well - - √ GW-200 Simuri (Saengga) Village; Well 1 20 28’ 9.9” 1330 6’ √ √ 23.7” GW-250 Simuri (Saengga) Village; Well 2 20 28’ 8,.58” 1330 6’ √ √ 20.28” GW-260 Simuri (Saengga) Village; Well 2A - - √ GW-300 Tanah Merah Village (old village); 20 26’12.18” 1330 6’ √ √ Well 1 54.42” GW-350 Tanah Merah Village (old village); 20 26’ 1330 7’ √ √ Well 2 14.22” 51.66” GW-400 Japanese Air strip √ Source: ANDAL 2002
Monitoring results based on AMDAL 2002 are summarized in Table II-14.
As part of the Environmental Baseline Study for the AMDAL study of the proposed Tangguh LNG Development Project, samples were also taken in community shallow wells in kampong Saengga and Tanah Merah Baru. The wells generally were of less than 5 m depth, so that the water originated from the unconfined aquifer layer near the ground surface. Many community members also installed simple roofs to catch rainwater for additional supply besides the water from shallow wells. The locations of SGW-01 and SGW-02 are shown in Figure II-30 and Figure II-31.
It is possbible that the water from shallow wells and rainwater will decrease during the dry season, particularly for drought during prolonged El Nino, so that the community will have to depend on the water network supply from deeper well built by Tangguh LNG to groundwater depth in the confined aquifer in the Steenkool Formation.
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Map II-8 Sampling Locations of Groundwater
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Figure II-30 SGW01 Community Well in Saengga
Figure II-31 SGW02 Community Well in Saengga
Groundwater samples were taken during the dry season in August 2012 and wet season in March 2013. Laboratory analysis results are presented in Table II-12. Low pH values ( 5.24, lower than quality standard of >6) and other parameters such as nitrite and coliform indicate local groundwater recharge.
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Table II-12 Results of Groundwater Quality Analysis, Survey 2012-2013
Location
No. Parameter Unit Quality Standard* DGW 01 SGW 01 SGW 02 GW 01 Wet Dry Wet Dry Wet Dry Wet Dry Physical Properties 1 pH - 6 - 9 8.32 7.93 5.39 5.51 5.95 5.24 7.14 5.75 2 Temperature °C ± 3 26.9 25.0 27.3 26.1 26.9 25.8 26.4 24.6 Total Dissolved Solids 3 mg/L 1.000 381 344 23 25 17 20 179 89 , TDS Nutrients
1 Nitrate, NO3-N mg/L 10 0.045 0.463 0.170 <0.005 <0.005 0.010 0.223 8.63
2 Nitrite, NO2-N mg/L 0.06 0.765 1.37 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Microbiology 1 E.Coli MPN/100ml 100 2 ND 7 1 128 13 ND ND 2 Total Coliform MPN/100ml 1,000 187 179 548 99 >2420 225 14 4 Dissolved Metals 1 Arsenic, As mg/L 0.05 0.0010 <0.0005 0.0014 0.0006 0.0005 0.0007 0.0010 <0.0005 2 Cadmium, Cd mg/L 0.01 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 0.0001 <0.0001 0.0002 Chromium 3 mg/L 0.05 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 Hexavalent, Cr6+ 4 Copper, Cu mg/L 0.02 0.02 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 5 Iron, Fe mg/L 0.3 0.10 <0.05 0.26 0.170 0.16 0.060 <0.05 <0.05 6 Lead, Pb mg/L 0.03 0.004 <0.001 0.001 <0.001 <0.001 <0.001 <0.001 0.002 7 Selenium, Se mg/L 0.01 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 * Quality standard based on PP 82 Year 2001, Class I (as Drinking Water Standard)
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Tangguh LNG Area In the Tangguh LNG area, there are 19 monitoring wells to observe the groundwater condition around the existing landfill area. The wells are regularly monitored by Tangguh LNG as part of the AMDAL 2002 commitment and reported to Ministry of the Environment (KLH) every six months. The data below originates from monitoring made by Tangguh LNG between October – December 2010 to January - September 2011.
Table II-13 Coordinates of Sampling Locations for Groundwater Monitoring Coordinates Well # South Latitude East Longitude Well #6 02º 27’ 19.6” 133º 08’ 52.9” Well #7 02º 27’ 16.3” 133º 08’ 52.7” Well #8 02º 27’ 17.7” 133º 08’ 49.3” Well #9 02º 27’ 26.3” 133º 08’ 49.0” Well #10 02º 27’ 22.2” 133º 08’ 51.2” Well #11 02º 27’ 24.3” 133º 08’ 46.4” Well #12 02º 27’ 20.1” 133º 08’ 47.9” Well #13 02º 26’ 58.4” 133º 08’ 50.4” Well #14 02º 27’ 05.7” 133º 08’ 51.6” Well #15 02º 26’ 58.8” 133º 08’ 53.3” Well #16 02º 27’ 24.8” 133º 08’ 46.7” Well #17 02º 27’ 02.2” 133º 08’ 48.8” Well #18 02º 27’ 05.9” 133º 08’ 48.8” Well #19 02º 27’ 02.6” 133º 08’ 53.0” Well #20 02º 27’ 06.3” 133º 08’ 56.6” Well #22 02º 27’ 10.1” 133º 08’ 57.1” Well #23 02º 27’ 09.4” 133º 08’ 54.6” Well #24 02º 27’ 08.7” 133º 09’ 01.3” Well #25 02º 27’ 06.0” 133º 09’ 02.4”
Monitoring wells are located around the solid waste management facility area or near the present landfill facility, as shown in Figure II-32 and also in Map II-8. Monitoring wells are further added to the new landfill area. The groundwater monitoring wells are built in the uppermost part near the surface of the Steenkool Formation dominated by dark grey claystone interspersed with sand. The wells were periodically monitored every six months to detect the depth of the groundwater table and samples were taken for analysis of physical and chemical properties of groundwater. In general, monitoring of shallow groundwater provided water quality baseline data, in which several natural heavy metals were recorded as exceeding quality standard (Government Regulation No 82 Year 2001) as shown in Table II-14. COD and BOD values were recorded slightly higher (elevated) during operation of the organic waste disposal site used by EPC contractor during phase I Tangguh LNG construction period. The organic waste
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disposal site was re-excavated and reclaimed. Organic waste was moved to the organic landfill built near the area with suitable design. The improvement made succeeded in restoring groundwater quality and upon further monitoring in which the outcomes were consistently good, the groundwater monitoring program around the former organic waste disposal pits during the construction period became less intensive.
The groundwater table in the Steenkool Formation near the surface reflects surface topography with numerous drainage outlets leading to water bodies and Bintuni Bay.
Figure II-32 Location of Groundwater Monitoring Wells
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Map II-9 Location of Groundwater Monitoring Wells – Tangguh LNG Construction Phase
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The majority of water quality parameters in samples taken met Class I water quality standard according to Government of Indonesia Regulation No. 82 Year 2001, except for several parameters such as pH, Total Coliform, chromium hexavalent, iron, lead, manganese, as shown in Table II-14.
Table II-14 Groundwater Parameters Exceeding Clean Water Quality Standard AMDAL 2002 2010 2011 PP No. Mi Parameter Unit Min Max Min Max Max 82/2001 n Physical 6.3 pH - 6 - 9 3.99 7.89 6.35 10.9 4 8.91 Microbiology Dissolved Metals Chromium Hexavalent, 0.22 (Cr6+) mg/L 0.,05 0.001 9 - - - - 0.0 Iron, Fe mg/L 0.3 0.1 29.2 0.02 1.42 2 4 Lead, Pb mg/L 0.03 <0.00 0.08 1 2 - - - - Manganese, Mn mg/L 1 <0.01 13.1 - - - -
2.1.6 Soils
2.1.6.1 Soil Map Units
Locations of soil observation are in the Tangguh LNG area boundary. Based on landform, the project area is classified into three Soil Map Units (SPT). Four soil orders are found in the SPTs, namely Entisols, Inceptisols, Ultisols and Spodosols. The soil types are encountered in associations. Distribution of SPT is shown in Map II-9, while characteristics of each SPT are presented in Table II-15.
Soil Map Unit (SPT) 1 (Entisols) SPT-1 Entisols are located on the north shoreline of the project area. The landform of the SPT consists of coastal shoal and tidal swamp (mangrove swamp) that are intermittently found along the shores. Mangrove swamp of Kajapah (KJP) land unit are found in a narrow area. Mangrove swamp are directly influenced by tides. In some places they are permanently inundated while in other areas far from the shoreline they are tidal swamps. No other vegetation is found in the area other than mangrove. In other places, the areas approaching fresh water (brackish water) mangrove gives way to other nipa palm vegetation. Based on the block map (Map II-10), the mangrove swamp belongs to Block E. Soils in the mangrove swamp are very poorly drained, unstructured (massive) and are of fine texture. In the USDA (United States Department of Agriculture) classification in great group level, soils with properties as described above are in the category of Hydraquents.
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Along the shoreline, besides tidal landforms of mangrove swamp, other coastal shoal landforms of Putting (PTG) land unit with secondary forest land cover are found. The coastal shoals have undeveloped soil, good drainage to very well drained, deep solum and generally soil texture of sandy clay or clayey sand. The soil is relatively newly formed (recent soil). In the USDA soil classification the great group level is known as Quartzipsamment.
Soil Map Unit 2 (Association of Ultisols and Inceptisols) SPT-2 The Ultisols and Inceptisols association are soils found in mild slopes (hillock complex), alluvial folds with undulating or hilly landform at elevation <50 meter above sea level. The area is characterized by lowland forest and appears to be untouched by the local population.
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SOIL MAP UNIT
Note: Option B, is the preferred option to be further assessed.
Map II-10 Soil Map Unit (SPT) in Land Area to be Cleared for the Tangguh LNG Expansion Project
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Note: Option B, is the preferred option to be further assessed.
Map II-11 Locations of Blocks and Soil Sampling
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At eastern of the Tangguh LNG, there is land with low hills. Blocks included in the landform are Block B and a small portion of Block A in the east. The Soil Map Unit (SPT) is association between ultisols and inceptisols which ultisols are represented by hapludults while inceptisols are represented by dystropepts.
Ultisols are soils with deep to very deep effective depth. Argillic horizon , namely the clay accumulation horizon (horizon B) containing 1.2 times clay content in the upper layer. Base saturation is less than 35% (low) and acidic in nature. Hapludults are reddish yellow clays with deep solum, medium drainage, acidic soil reaction and are widely-dispersed in hilly areas. These soils are never dry for 90 cumulative days in a year (udic moisture).
Besides ultisols, inceptisol soil type was also found in association. This soil type is developing soil or recently developing soil characterized by weak structure, less horizonation and displacement of fine particles so that clay content in fine fractions is below 8%. Thus each horizon will be bright colored. The soil type is classified as dystropepts, i.e. greyish colored sandy clay soil with somewhat blockage in drainage, deep solum and slightly acidic reaction. The soil type is frequently encountered at the base of hill valleys.
Soil Map Unit 3 ( Association of Ultisols and Spodosols) SPT-3 The Ultisols and Spodosols association are found in incised terrace landforms. Those are formed from many incised, low and undulating land forms, encompassing undulating and hilly land. The ultisols and spodosols association occupy an undulating to hilly landscape with 8-30% slope. This landform is most dominant in the Tangguh LNG area.
Between both types of soils, the ultisols order are dominant in the Tangguh LNG area. The effective depth is deep to very deep. There is an argillic horizon, i.e. clay accumulation horizon (horizon B) containing 1.2 times clay content above it. Base saturation is less than 35% (low) and acidic. The soils are never dry for 90 cumulative days a year (udic moisture). In USDA’s soil classification, the sub-order level is known as Udult. Ultisols are dominated by grey color (gley) indicating much blockage in drainage encountered in hilly land or in basins. At edges of hills the soil is reddish yellow since it is moderately well drained. Clay accumulation occurs in the lower horizon, effective depth is very deep and slightly acidic. Ultisols encountered in Block F are characterized by upper layer containing organic materials to a depth of 10-15 cm. In USDA’s soil classification, the sub-order level is known as Humults.
Spodosols occupy a small and sporadic part of flat valleys and are associated with ultisols. The main characteristic of this soil type is advanced leaching until the remaining bright colored quartz sand fraction. The upper layer is dark colored due to high level of organic materials. In the USDA’s soil classification, the sub-order level is known as Ortdods.
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Table II-15 Soil Map Unit Characteristics in Area to be Cleared
Soil Type Area SP Slope Landform Main Material T Representative (%) Order ha % Great Group 1 Entisols Hydraquent and Tidal swamp <2 Aluvium marin Quartzipsamment and coastal 5 2 shoal 2 Ultisols Hapludults and Mildly- 8-25 Conglomerate and Dystropepts sloping hills complex and 62 19 Inceptisols mudstone association 3 Ultisols Hapludult, Incised 3 -16 Conglomerate and Humuldt and terrace complex and 255 79 Spodosols Ortods mudstone association Total land area to be cleared 321 100
2.1.6.2 Soil Physical Properties The soil physical properties was observed in the field and laboratory consist of: texture, structure, surface rock and effective depth, color, Bulk Density (BD) and Particle Density (PD) as well as permeability. Sampling locations of soil physical properties are shown in Map II-10. Laboratory analysis results of soil physical properties are shown in Appendix II-5. Observation of land physical parameters is required to determine the potential erosion.
Soil Texture The soil texture refers to the relative ratio of sand, silt and clay fractions. Soil texture is related to soil infiltration rate, water status in soil (groundwater content), soil permeability and soil porosity. Laboratory analysis results of soil fractions are shown in Table II-16 and Figure II-33. Based on experience in other places, such SPT-1 soils have slightly different texture variation in between mangrove swamp and coastal shoal landforms. Mangrove swamp area generally has fine soil texture (clay loam) on the surface and coarse texture (sand-clay sand) is encountered several cm below, whereas SPT-1 with coastal shoal of the soil surface has coarse texture (sandy sand–loam). SPT-2 and SPT-3 have finer textures than SPT-1. Ultisols in SPT-2 and SPT-3 have higher clay content (silty loam-silty clay) compared to inceptisols and spodosols in the same SPT (sandy loam-loam). Soils containing much clay are more resistant to erosion. In general the texture class range in each SPT indicates varying water holding capacity. Water holding capacity is lowest in SPT-1, medium in SPT-3 and high in SPT-2.
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Table II-16 Fractions of Soil Texture in Soil Map Unit at the Tangguh LNG Site Texture of 10 Fractions (%) Sampling Sand Fraction Silt Fraction Clay Fraction location >1.000 µ 500-1.000 µ 200-500 µ 100-200 µ 50-100 µ 20-50 µ 10-20 µ 2-10 µ 0,05-2 µ <0,05 µ SPT-1 F-9 0.9 0.6 5.9 24.8 19.8 19.1 3.8 2.1 18.2 4.8 F-1 0.4 0.2 2.3 13.7 25.4 24.2 13.5 4.3 12.2 3.8 SPT-2 F-2 0.1 0.3 6.5 6.4 13.7 32.2 20 0.8 14.8 6.2 F-8 0.1 0.7 8.3 11.8 28.1 29.9 17.9 2.2 0.8 0.2 F-3 0.7 4.8 24.8 22.5 16.2 15.7 8.1 3.2 2.9 1.1 F-4 21.1 0.3 1.2 5.5 14.9 30.5 19.8 1.7 3.2 1.8 F-5 0.1 0.8 0.9 5.4 21.8 37.8 12.5 3.7 11.2 5.8 F-6 0.2 0.6 9.6 17.4 31.2 22.4 7.2 2.4 6.7 2.3 SPT-3 F-7 0.1 0.8 1.6 2.3 6.2 29.8 15.1 4.1 32.8 7.2 F-10 0.1 0.3 1.2 5.5 14.9 39.4 23.2 9.4 4.1 1.9 F-13 0.4 3.9 51.2 14.9 5.6 6.8 3.2 2 8.2 3.8 F-11 0.5 0.1 29.6 23.1 16.7 17.8 6.6 1.6 2.1 1.9 F-12 0.1 0.7 25.6 9.9 8.7 26.3 18.7 4 3.8 2.2
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Figure II-33 Percentage of Sand, Silt, and Clay Fractions for Soil Texture in Each SPT at the Tangguh LNG Site
Soil Structure Soil structure is directly observed in the field, i.e. form, size and level of development. Soil structure in SPT-1 is unformed (sand) since the soil in this SPT is recent soil. SPT-2 and SPT-3 generally are of flakey structure on the upper layer (between 0-5 cm), and clumps in the bottom layer (between 5-20 cm) except for lower layer spodosols (5-20 cm) are generally flakes-unstructured (loose). Firmness of structure is generally in the lower layer. Soils with firm structure such as ultisols in SPT-2 and SPT-3 are more resilient to erosion compared with inceptisols and spodosols.
Surface Rock and Effective Depth Surface rocks are not encountered in all SPT except for spodosols that has lost its upper layer (organic material). Surface rock in spodosols are encountered in small number (<5%). Effective depth in all SPT is over 100 cm except for inceptisols in Block E, with effective depth of about 30 cm due to the presence of pan layer in the form of clay fraction and iron accumulation.
Soil Color Soil color in each block varies from brown, yellowish brown, reddish yellow and gley. Soils in SPT-2 and SPT-3 on slopes or terraces and on mildly sloping hilltops are brown-colored on the surface layer (10 YR 3/4) and the layer below is reddish colored (7.5 YR 6/8). Soils in valleys are generally gley colored (7.5 YR 7/2) in the lower layer. Soil color indicates the drainage condition in soils . Brown to reddish or yellowish colored soils generally indicate good drainage, while gley colored soils indicate poor drainage. Drainage is one of the soil properties observed based on the velocity of water flow from a soil plot, both as run off and absorption into the soil. Drainage can also signify as frequency and duration of the soil to be free from water saturation.
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Bulk Density (BD) and Particle Density (PD) Bulk density indicates soil density per unit volume of soil (with soil pores) while Particle Density refers to soil density per unit soil volume (without soil pores). Values of BD and PD are directly proportional to the coarseness level of soil particles, the finer of soil particles will be heavier in the weight. Values of BD and PD are associated with ease of plant root penetration into the soil, soil drainage and aeration and other physical properties. Weighted value of soil varies from one soil location to another, depending on variations in organic matter content, texture, structure and surface vegetation.
Table II-17 Analysis of Soil Physical Properties in Soil Map Unit in the Tangguh LNG Location Water Content BD PD Total Pores Permeability Location of Sampling (% vol) (g/cc) (g/cc) Space (cm/hour) SMU 1 F-9 33.5 1.22 2.43 49.9 2.42 SMU 2 F-1 36.5 1.25 2.35 46.7 1.96 F-2 36.5 1.22 2.38 48.6 0.71 F-8 49.7 1.08 2.4 55.3 0.19 SMU 3 F-3 36.1 1.43 2.5 43.0 8.52 F-4 27.2 1.37 2.56 46.5 7.82 F-5 39.6 1.37 2.54 46.0 2.49 F-6 39.4 1.21 2.37 49.0 5.87 F-7 38.9 1.29 2.51 49.6 1.24 F-10 24.9 1.17 2.37 50.9 0.17 F-13 26.2 1.13 2.13 46.8 8.88 F-11 30.3 1.56 2.18 28.4 3.75 F-12 29.8 1.59 2.64 39.9 2.22 Note: Pore diameter (pF): (1) 296µ, (2) 28.6µ, (2.54) 8.6µ, and (4.2) 0.2µ Source: Primary data, Soil Physics Laboratory Analysis, Soil Research Center-Bogor, July 2013
Analysis results as shown in Table II-17 indicate values of BD and PD in coastal shoal of SPT-1 where BD = 1.22 g/cc and PD = 2.43 g/cc. In SPT-2 average BD is 1.18 gram/cc and average PD is 2,38 gram/cc, while in SPT-3 average BD is 1.35 g/cc and average PD is 2,42 g/cc. Values of BD and PD obtained in SPT-2 and SPT-3 tends to be high due to the soil samples were taken at 7-15 cm from the soil surface. In this layer, organic matter content has decreased so that the soil is more compact than the overlying layers.
Soil Permeability Soil permeability refers to soil capacity to allow water to pass through it. Soil permeability is one of the soil properties that greatly affect soil infiltration rate, surface runoff and soil sensitivity to erosion. In permeable soils, soil infiltration rate is high so that surface flow rate is low, the soil surface can avoid erosion hazard. Soil permeability in SPT-1 was generally in the category of high due to the dominant sand which water can pass through it easily. In SPT-2 and SPT-3, the permeabilities
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were categorized as slow to rapid. In ultisols with high clay content, permeability was categorized as slow (average 2.0 cm/hour). Spodosols with high sand content, had permeability of medium category (5.87-8.52 cm/hour). Permeability was in line with soil texture found in each SPT.
2.1.6.3 Soil Chemical Properties
Sampling locations for the analysis of soil chemical properties are shown in Map II-10. Descriptions of soil chemical properties were based on the analysis of soil samples in the laboratory, as shown in Appendix II-5. Main soil fertility components encompassed soil reaction; organic materials; N total and C/N ratio; total and available phosphor as well as potassium; cation exchange capacity; base saturation; and Al saturation. Assessment of soil chemical properties referred to criteria of Soil Research Center Staff (PPT, 1983) as shown in Table II-18. Results of the assessment are presented in Table II-18.
Table II-18 Assessment Criterias of Soil Chemical Properties Based on Soil Research Center Staff, 1983 Soil Parameter Unit Very Low (VL) Low (L) Medium (M) High (H) Very High (VH) C – Org % < 1 1– 2 2.01 – 3.00 3.01 – 5.0 > 5.0 N % <0.1 0.1-0.2 0.21-0.5 0.51-0.75 >0.75 C/N - <0.1 0.1 – 0.2 0.21 – 0.5 0.51 – 0.75 > 0.75
P2O5 HCl mg/100g <10 10-20 21-40 41-60 >60
P2O5 Bray-1 ppm <10 10-15 16-25 26-35 >35
P2O5 Olsen ppm <10 10-25 26-45 46-60 >60
K2O HCl 25% mg/100g <10 10-20 21-40 41-60 >60 KTK me/100g <5 5-16 17-24 25-40 >40 Ca me/100g < 2 2 – 5 6 – 10 11 – 20 >20 Mg me/100g <0.4 0.4 – 1 1.1 – 2 2.1 – 8.0 >8 0.10 – K me/100g <0.10 0.3 – 0.5 0.6 – 1.0 >1 0.2 Na me/100g <0.1 0.1 – 0.3 0.4 – 0.7 0.8 – 1.0 >1,0 Base Saturation % <20 20-35 36-50 51-70 >70 (KB) Aluminum % <10 10-20 21-30 31-60 >60 Source: Soil Research Center, 1983
Soil Reaction
The pH-H2O values of soil in all sampling locations (SPT-1 to SPT-3) are acidic, ranging between 3.6-5.0; while pH-KCl ranges between 3.3 – 5.9. Soil acidity commonly occurs in areas of high rainfall. This conforms to the very high rainfall in the vicinity of the Tangguh LNG site with average annual rainfall reaching 2,938 mm. High rainfall causes leaching of bases from adsorption (jerapan) complex and
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loss through drainage water. In condition where bases are fully leached, only Al and H cations remain as dominant cations causing soil to have acidic reaction (Coleman and Thomas, 1967).
Acidic soil reaction (pH) results in very low availability of nutrients (Hardjowigeno, 2006). Aluminum element is both toxic and binds phosphor, which thus cannot be absorbed by plants. In acidic soils, micro elements easily dissolve so that micro elements such as Fe, Zn, Mn and Cu are found in extremely large quantities, thus are toxic for plants.
Organic Materials The higher of the soil organic materials will be the better or more fertile soil. Organic materials content of soil is stated in percent C-organic. Value of soil C- organic around the Tangguh LNG is shown in Table II-19. In SPT-1 (1.56%) at coastal shoal, C-organic is very low while in mangrove swamp the upper layer is high and the lower layer is low. In SPT-2, all C-organic values are low (1.22-1.72%) while in SPT-3 C-organic content is low to high (1.0-3.52%). The low C- organic in SPT-1 is due to coarse soil texture (sand dominance) so that organic material can easily experience leaching, supported by high rainfall. Sloping areas with small hills in SPT-2 causing organic matter from decomposition of plant organic matter easily eroded to valleys, so that organic matter of the soil on hillside slopes is generally low.
Total N and C/N Ratio Nitrogen is a main nutrient element of plants that will rapidly react and real. N as nutrient will stimulate the growth of vegetation (on the ground), provide green color, enlarge cereal grains, raise protein content of plants. Thus N content of soil is an essential component in soil fertility. N-total reflects potential nitrogen content in soils enable to be absorbed by plants. The higher total N content, the soils tend to make good influence to the plant growth. N content in all SPTs are categorized very low to medium (0.09-0.25%), with dominantly low category as shown in Table II-19.
The C/N ratio is defined as relative amount of the both elements in fresh organic matter, humus or in soils. The C/N ratio also provides understanding of decomposition of organic matter and release or immobilization of N-soil. High ratios of C/N indicate that organic matter is not completely decomposed or indicate high microorganism activities and vice versa, i.e. if the C/N ratio low, it indicates nearly complete decomposition that signifies the microorganism activity has decreased. According to Tisdale et al. (1985), organic matter with C/N ratio more than 30:1, immobilisation of N in soil will occur, C/N between 20 and 30 signifies no release or immobilization of N, while if C/N of less than 20, N will be released into the soil. Thus, high ratios of C/N do not ensure higher soil fertility. Soil analyses results indicate that the C/N ratios in all SPTs are categorized low-medium (10-14).
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Total and Available of Phosphor (P) and Potassium (K) Phosphor content in soil has significant meaning for plants and its presence is highly critical. Lack of this element in soils prevents plants from absorbing other elements (Guswono, 1985). Phosphor plays a role in cell division activities, formation of protein, albumin, formation of plant generative system, and resiliency against disease. The total form indicates the P and K content or reserve in soil or known as potential, while the available form is a form that able to be absorbed by plant roots or actual.
In all SPTs, total content of Phosphor (P2O5) or P is categorized very low to high (3- 46 mg/100g soil) and available P content is categorized very low to high (3.1-33.5 ppm) with very low to low dominance.
The element of Potassium (K) in plants will aid in accelerating and facilitating formation of complex compounds, mainly compounds with Cl and Mg. K functions to accelerate carbohydrate formation, strengthen cell walls, improve seed quality mainly paddy and tubers.
In SPT-2 and SPT-3 total Potassium (K2O) concentration is categorized very low to low (1-18 mg/100g soil). Similarly, available Potassium content is categorized very low to low (17 - 78 ppm).
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Table II-19 Analysis of Soil Physical Properties in Soil Map Unit at Tangguh LNG (1) SPT-1 SPT-2 SPT-3
Parameter Unit KSB XVII KSB II KSB III KSB IV KSB XV KSB I KSB V KSB VI KSB VII KSB VIII KSB IX KSB X Block G Block A Block A Block A Block B Block A Block A Block A Block A Block A Block A Block A
pH H2O - 4,2 4.0 5.0 4.3 4.5 3.8 4.3 4.0 4.0 3.7 3.9 3.6 Extract pH KCl - 3.4 3.5 4.2 3.5 3.7 3.4 3.1 3.7 3.6 3.4 3.5 3.3 Walkley & Black © 1.56 1.63 1.72 1.22 1.3 3.52 1.84 2.23 2.05 2.93 2.41 2.7 Organic Matter % N-Kjeldahl 0.15 0.13 0.12 0.09 0.13 0.25 0.15 0.21 0.21 0.25 0.23 0.25
C/N - 10 13 14 14 10 14 12 11 10 12 10 11
P2O5 19 6 17 8 46 13 5 6 3 12 14 11 HCL 25% mg/100g K2O 7 3 10 3 18 7 2 3 4 5 8 8
Bray 1 P2O5 7.5 7 11.1 10.9 3.1 20.7 11.6 6.8 9.3 12.6 8.2 8.2 ppm Morgan K2O 31 21 53 27 78 37 17 23 37 31 72 78 Ca 0.82 0.28 5.07 1.76 6.47 0.33 0.32 0.38 0.22 0.84 0.58 0.3 Mg 0.22 0.19 1.6 0.48 0.91 0.38 0.22 0.24 0.22 0.31 0.38 0.26 Cation K 0.06 0.04 0.1 0.05 0.15 0.07 0.03 0.04 0.07 0.06 0.14 0.15 Exchange cmolc/kg Value Na 0.04 0.01 0.03 0.01 0.04 0.05 0.02 0.19 0.32 0 0.01 0.01 (NH -Acetate 4 Total 1.14 0.52 6.8 2.3 7.57 0.83 0.59 0.85 0.83 1.21 1.11 0.72 1N, pH7) KTK 6.85 5.85 9.94 5.9 17.04 14.75 2.29 3.85 5.16 10.22 9.08 12 KB % 17 9 68 39 44 6 26 22 16 12 12 9 Al3+ 1.15 3.15 0.04 3.19 3.73 6.66 0.23 1.87 2.06 4.75 4.56 5.57 KCL 1N cmolc/kg H+ 0.33 0.48 0.17 0.4 0.55 0.86 0.25 0.22 0.35 0.72 0.51 0.77 Fe % 0.47 5.63 6.12 3.72 1.06 9.94 0.10 3.51 1.07 4.72 8.02 6.27 Mn ppm 2.10 5.00 1.319.00 61.00 104.70 21.00 5.00 13.00 4.00 55.00 23.00 7.00 Cu ppm 0.70 td 4.30 0.30 1.50 td td td td td td td Zn ppm 3.30 66.30 142.80 15.00 20.50 43.20 td 11.50 9.30 66.20 41.30 11.60 Pb ppm td td Td td td td td 0.20 td td td td Cd ppm 0.90 1.38 0.81 0.71 1.69 0.71 0.01 0.03 0.15 0.63 0.74 0.22 Ni ppm td 3.30 10.10 11.70 10.00 1.20 0.70 1.10 1.70 5.90 4.70 0.40 Cr ppm 23.20 25.90 26.80 20.20 25.90 32.40 6.80 14.80 13.40 19.90 24.40 21.60 As ppm 4.50 1.30 1.20 2.30 3.70 0.40 0.80 0.50 0.60 1.60 1.80 1.10 Se ppm td td td td td td td td td td td td Hg ppm 0.09 td td td td td td td td td td td
Source: Primary data, Soil Physics Laboratory Analysis, Soil Research Center-Bogor, July 2013
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Table II-20 Analysis of Soil Physical properties in Soil Map Unit at Tangguh LNG (2) SPT-3
Parameter Unit KSB XI KSB XII KSB XII KSB XIII KSB XIV KSB XVI KSB XVIII KSB XIX KSB XX KSB XXI KSB XXII KSB XXIII Block A Block A Block A Block A Block A Block C Block E Block E Block E Block F Block F Block F
pH H2O - 3.6 4.1 4.1 3.9 4.2 4.4 4.4 4.1 4.4 3.8 4.1 3.9 Extract pH KCl - 3.3 5.9 5.9 3.6 3.1 3.7 3.9 3.8 3.6 3.4 3.5 3.4 Walkley & Black © 1.79 1.52 1.52 2.48 1.43 2.62 1.25 1.05 1.32 2.31 1.73 1 Organic % N-Kjeldahl 0.15 0.15 0.15 0.23 0.13 0.25 0.11 0.1 0.11 0.19 0.15 0.09 Materials C/N - 12 10 10 11 11 11 11 11 12 12 12 11
P2O5 7 23 23 17 19 21 21 16 19 15 16 17 HCL 25% mg/100g K2O 1 9 9 8 13 11 9 5 8 4 4 4
Bray 1 P2O5 29.8 5.1 5.1 9.1 3.3 33.5 3.9 5.8 3.9 3.4 7.8 6.3 ppm Morgan K2O 36 63 63 71 47 67 33 53 42 41 17 27 Ca 0.52 1.17 1.17 0.9 0.98 3.17 3.43 1.1 1.76 0.72 0.72 0.84 Mg 0.32 0.43 0.43 0.38 0.31 0.61 0.42 0.25 0.4 0.28 0.25 0.2 Cation K 0.07 0.12 0.12 0.14 0.09 0.13 0.06 0.1 0.08 0.08 0.03 0.05 Exchange cmolc/kg Value Na 0.01 0.12 0.12 0.05 0.03 0.06 0.03 0.03 0.07 0.07 0.07 0.06 (NH -Acetat 4 Total 0.92 1.84 1.84 1.47 1.41 3.97 3.94 1.48 2.31 1.15 1.07 1.15 1N. pH7) KTK 4.56 12.8 12.8 8.4 11.74 12.31 10.53 4.75 11.72 9.52 7.53 7.22 KB % 22 14 14 18 12 32 37 31 20 12 14 16 Al3+ 1.53 3.88 3.88 0.26 3.12 0.1 1.43 0.26 2.81 0.58 1.49 1.63 KCL 1N cmolc/kg H+ 0.51 0.57 0.57 0.83 0.52 0.41 0.35 0.4 0.5 1.03 0.49 0.62 Fe % 0.51 1.02 1.02 0.02 0.72 0.03 0.52 0.02 0.05 0.02 0.06 0.06 Mn ppm 18.00 27.30 27.30 2.40 5.70 5.60 11.50 2.00 5.80 1.10 1.10 2.40 Cu ppm td td td 0.20 td 0.50 td 0.40 0.50 0.20 0.10 0.10 Zn ppm 11.40 12.50 12.50 td 11.70 1.00 0.20 5.60 1.30 0.00 0.90 0.60 Pb ppm td td td td td td td td td td td td Cd ppm 0.64 1.74 1.74 0.01 1.23 0.03 0.91 0.02 0.87 0.02 0.03 0.03 Ni ppm 1.30 3.20 3.20 td 1.50 td 0.50 td 3.60 1.50 td td Cr ppm 28.00 28.00 19.10 26.50 10.00 33.60 10.10 30.30 5.30 8.10 13.70 As ppm 3.00 3.50 3.50 0.60 4.00 0.70 3.50 0.50 4.50 0.10 0.60 0.40 Se ppm td td td td td td td td td td td td Hg ppm td td td td 0.12 td td td td 0.07 td 0.09
Source: Primary data, Soil Physics Laboratory Analysis , Soil Research Center-Bogor, July 2013
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Cation Exchange Capacity One of soil chemical properties closely related to nutrient availability for plants and as an indicator of soil fertility is Cation Exchange Capacity (CEC or KTK). KTK is the total number of exchangeable cations on the surface of negatively charged colloids. The unit of KTK measurement is milliequivalent cation in 100 gram soil
(me/100 g) or centimole charge per kg soil ( cmolc/kg). Soils with high KTK when are dominated by base cations such as Ca, Mg, K and Na this may increase soil fertility, however when cations in soil are dominated by acid cations , namely Al, H cations, this may reduce soil fertility due to their toxic nature for plants (Hanafiah, 2006). The obtained KTK values are averagelt categorized very low-medium (2.29- 17.04), only at block B that the KTK is categorozed medium (17.04) due to clay content as a source of colloids is higher than that of other lands. Soils with criteria of very low-low KTK , means poor capacity of soils to absorb and provide nutrient elements.
Base Saturation Base saturation (BS) indicates the ratio between number of base cations to total cations (total base cation and acid cation) found in soil adsorption complex. The maximum amount of cations able to be adsorbed by soil indicates the cation exchange capacity value of the soil. Base cations (Ca++, Mg++, K+, Na+) are generally nutrient elements required by plants. Base cations are generally easily leached , so that soils with low leaching BS are infertile soils. Soils found in all SPT-3 generally have very low-medium base saturation (6-37%). In SPT-2 it is very low to high (9- 68%). The presence of calcium and magnesium of higher value in SPT-2 contributes to high base saturation value. As the base saturation value of SPT-2 is higher compared to SPT-3, soil fertility in SPT-2 is higher than in SPT-3.
Active Aluminum Aluminum in the form of (Al+++) ions is toxic for plants. The presence of Aluminum in soils will generally cause soils to be acidic that will lower soil fertility level. In very small amounts, aluminum in plants will aid the metabolism process, however if the soil indicates large amounts this will become toxic, stunt growth and cause abnormal leaf growth. Active Aluminum content in soils is expressed as Aluminum saturation (%), i.e. the amount of Al+++ concentration toward KTK. Al saturation in all SPTs is very low (0.04-6.66 cmolC/kg or me/100g). Thus the possibility of toxicity by Aluminum in all SPTs in the proposed Tangguh LNG Expansion Project location is low.
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Table II-21 Analysis of Soil Physical Properties Assessment Criteria * (1) SPT 1 SPT 2 SPT 3
Parameter Unit K-17 K-2 K-3 K-4 K-15 K-1 K-5 K-6 K-7 K-8 K-9 K-10 Block G Block A Block A Block A Block B Block A Block A Block A Block A Block A Block A Block A
Extract pH-H2O - Very acidic Very Acidic Acidic Very acidic Acidic Very acidic Very acidic Very acidic Very acidic Very acidic Very acidic Very acidic
Walkley & Black (C) % L L L L L H L M M M M M Organic Matter N-Kejldahl % L L L VL L M L M M M M M C/N - L M M M L M M M L M L M
HCL 25% P2O5 mg/100g L VL L VL H L VL VL VL L L L
Bray 1 P2O5 VL VL L L VL M L VL VL L VL VL
K2O HCl 25% mg/100g VL VL L VL L VL VL VL VL VL VL VL KTK L L L L M L VL VL L L L L Ca VL VL M VL M VL VL VL VL VL VL VL Cation Exchange Capacity Mg cmolc/kg VL VL M L L VL VL VL VL VL VL VL (NH4-Acetat 1N, K VL VL L VL L VL VL VL VL VL L L pH7) Na VL VL VL VL VL VL VL L M VL VL VL KB % VL VL H M M VL L L VL VL VL VL Aluminum % VL VL VL VL VL VL VL VL VL VL VL VL Mn Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Zn Natural Natural Natural Natural Natural Natural - Natural Natural Natural Natural Natural Cd Natural Natural - - - Natural Natural Natural Natural Natural Natural Natural Ni - Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Cr Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural * Based on the results of soil chemistry analysis in Table II-21 Note: VL : Very Low L : Low M : Medium H : High VH : Very High More detailed criteria are shown in Table II-18
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Table II-22 Analysis of Soil Chemical Properties Assessment Criteria * (2) SPT 3
Parameter Unit K-6 K-12 K-13 K-14 K-16 K-18 K-19 K-20 K-21 K-22 K-23 Block A Block A Block A Block A Block C Block E Block E Block E Block F Block F Block F
Extract pH-H2O - Very acidic Very acidic Very acidic Very acidic Very acidic Very acidic Very acidic Very acidic Very acidic Very acidic Very acidic
Walkley & Black (C) % L L M L M L L L M L L Organic matter N-Kejldahl % L L M L M L L L L L VL C/N - M L M M M M M M M M M
HCL 25% P2O5 mg/100g VL M L L M M L L L L L
Bray 1 P2O5 H VL VL VL H VL VL VL VL VL VL
HCl 25% K2O mg/100g VL VL VL L L VL VL VL VL VL VL KTK VL L L L L L VL L L L L
Ca VL VL VL VL L L VL VL VL VL VL Cation Exchange Mg cmolc/kg VL L VL VL L L VL L VL VL VL Capacity (NH4-Acetat 1N, pH7) K VL L L VL L VL L VL VL VL VL Na VL L VL VL VL VL VL VL VL VL VL KB % L VL VL VL L M L L VL VL VL Aluminum % VL VL VL VL VL VL VL VL VL VL VL Mn Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Zn Natural Natural - Natural Natural Natural Natural Natural Natural Natural Natural Cd Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Ni Natural Natural - Natural - Natural - Natural Natural - - Cr Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural * Based on the results of soil chemistry analysis in Table II-22 Note: VL : Very Low L : Low M : Medium H : High VH : Very High More detailed criteria is shown in Table II-18
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2.1.6.4 Soil Erosion Sensitivity
Determination of soil erosion sensitivity can be seen from soil erosion rate with the general equation of Universal Soil Loss Equation – USLE. In the equation, rate of erosion is determined by rainfall erosivity index (R), soil erodibility (K), length and gradient of slope (LS) and soil cover and cropping management factors . The form of equation is as follows: A = R * K * L * S * C * P Where : A = Soil loss in ton/ha/year R = Rainfall erosivity factor K = Soil erodibility factor L = Slope length factor S = Slope gradient factor C = Cropping management factor P = Soil conservation factor
The rainfall erosivity index used to calculate erosion rate was based on monthly rainfall data in the Tangguh LNG. Data used was from January 2011 to June 2013. Rainfall erosivity index values were calculated using the Bols (1978) equation where EI30=6.119 (CH)1.21(HH)-0.47(maxp)0.53. In which EI30 is rain erosivity, CH (rainfall), HH (rain days), maxp (maximum daily rainfall in one month ). The rainfall erosivity indexes at the representative stations are presented in Table II-23.
Table II-23 Average Monthly Rainfall and Rainfall Index Value (R) Month Average Rainfall R Value January 292.3 17,449 February 244.0 8.013 March 272.7 10,106 April 272.7 11,869 May 250.3 10,091 June 289.3 9,020 July 95.0 2,130 August 89.0 2,394 September 199.0 6,597 October 65.5 2,171 November 137.5 6,502 December 292.3 9,024 Total 244.0 95,367 Source: Results of data analysis, 2013
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Soil erodibility value (K) was calculated from the Wischmeier and Smith (1978) equation in Arsyad (2000) where 100K=2.713M1.14(10)-4(12-a)+3.25(b-2)+(c-3). In which M=parameter of particle size, i.e. (%silt+% very fine sand)(100-%clay), a=organic matter (%Cx1.724), b=soil value, c=permeability value. Values of soil erodibility index in the study area are presented in Table II-24.
Table II-24 Soil Erodibility Values Soil Organic K Soil Map Dominant soil type Soil Texture Permeability Material index Structure Unit Content (%) value Rapid (coastal Coarse Hydraquents and Non- shoal) and slow SPT1 (sand- Low 0.11 Quartzipsamment structured (mangrove sandy clay) swamp) Fine (Silty Moderate- SPT2 Hapludults Lumpy Medium 0.74 clay) hindered Slightly SPT3 Hapludult coarse Lumpy Moderate Medium 0.55 (sandy clay) Source: Results of data analysis, 2013
Slope length and gradient (LS) Index Values Slope gradient on land to be cleared was quite varied, thus in order to facilitate computation, the slope length and gradient used in calculating erosion rate was the magnitude or value of the dominant slope length and gradient in each soil map unit. Values of slope length and gradient (LS) are presented in Table II-25.
Table II-25 Average Slope Length and Gradient Index of Each SPT (LS) SPT Gradient Slope Length LS Index 1 0 0 1 2 8 15 3.21 3 3 10 1.3
Index values of soil cover and cropping management factors (CP) Index value CP used to calculate erosion rate was based on land cover data.
Table II-26 Values of Land Cover Factor Index (C) Type of Soil Cover C Index Value Natural forest (primary forest) 0.001 Production forest (secondary forest) 0.005 Shrub 0.020 Source : Arsyad, 2000
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The value of soil management factor (P) in calculating soil erosion rate was based on soil conservation technique applied in a landscape. Soil conservation techniques were not applied yet or considered to have a value of one. Conservation technique will be applied according to the purpose of land to be utilized. Erosion rates for each geomorphology landform and land use is according to soil map unit in the area to be cleared for the proposed Tangguh LNG Expansion Project are shown in Table II-27.
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Table II-27 Calculation of Soil Erosion Rate in Each Soil Map Unit in the Area to be Cleared for the Proposed Tangguh LNG Development Project Land Cover Conservation Potential Erosion Environmental Baseline Natural Factor Erosion Hazard Level (C) (P) (ton/ha/year) Soil Map Primary Secondary Primary Secondary Primary Secondary Dominant Soil Type R K LS Shrub Without Without Without Shrub Shrub Unit forest forest forest forest forest forest Hydraquents and SMU1 953.67 0.21 1 0.001 0.02 0.005 0.001 0.001 0.001 0.02 0.40 0.10 S S S Quartzipsamment Hapludults and SMU2 95.367 0.74 3.21 0.001 0.02 0.005 0.001 0.001 0.001 0.23 4.53 1.13 S S S Dystropepts Hapludult, Humuldt SMU3 95.367 0.55 1.30 0.001 0.02 0.005 0.001 0.001 0.001 0.07 1.44 0.36 S S S and Ortods
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After soil erosion was calculated from the USLE equation shown in Table II-27, the results were compared with class of erosion hazard level as shown in Table II-28.
Table II-28 Erosion Hazard Level Based on Solum Thickness and Total Erosion Hazard (Total Maximum Erosion) Solum thickness Maximum erosion (ton/ha/year) (cm) < 15 15 – 60 60 – 180 180– 480 > 480 > 90 SR S S B SB 60 – 90 R B B SB SB 30 – 60 S SB SB SB SB < 30 B SB SB SB SB Note: SR = Very Low, R = Low, S = Medium, B = Heavy, SB = Very Heavy Source : Ministry of Forestry, 1986
Based on the criteria shown in Table II-28, it was concluded that erosion hazard level in each soil map unit (SPT) in the study location with thickness of solum 30-60 cm was in the medium category.
2.1.7 Geology
2.1.7.1 Geology and Stratigraphy Regional Geology The Papua region is located on the edge of the Australian continental lithospheric plate, which is currently moving west-northwest at a rate of 120 mm/year relative to the Caroline and Philippine oceanic plates (McCaffrey, 1996). The oblique collision between these plates has resulted in a broad zone of crustal deformation, the Melanesian orogeny (Simandjuntak and Barber, 1996). As a consequence of this oblique collision, a complex pattern of both compressional deformation, including folding and thrust faulting, and strike-slip faulting has developed.
Berau/Bintuni Bay is located in one of the most tectonically active regions of the world, within the collision zone between the northward moving Australian plate and the southward moving Philippine and Caroline plates. The collision zone is very complicated mainly caused by the presence of a series of smallmicroplates that have been caught up in the collision process. The region is prone to earthquakes (tectonic) and associated tsunamis. Bedrock consists of Tertiary carbonates, Quaternary siliclastic rocks and sediments that covering embedded Mesozoic sediments layers. The structure of the area is essentially an east-west trending fold and thrust belt flanked by foreland basin to the north and east (North Plain, Bomberai Plain, and Berau/Bintuni Bay) as shown in Figure II-34.
On the eastern side of Papua, collision of the Australian continental plate and the Philippine Sea oceanic plate began in latest Paleogene or early Neogene age (approximately 24 million years ago). The northern promontory of the Australian continent collided with an oceanic island volcanic arc located along the southern margin of the Philippine Sea plate. The remnants of the volcanic arc are now dispersed as a series of ophiolithic rocks found in the northern part of Papua New
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Guinea and Papua. Progressive collision of the two plates has resulted in the remnants of the former island arc being thrust back over the Australian plate, as well as the southward subduction of the Caroline/Philippine plate beneath the Australian plate, forming the New Guinea trench. The complex and ongoing plate collision has resulted in a broad zone of folding and faulting called the Highlands fold and thrust belt, which parallels the New Guinea trench. Ongoing deformation across this collisional belt is evidenced by the numerous (tectonic) earthquakes that occured in this region (Abers and McCaffrey, 1988).
On the western side of Papua, the complex interaction between several microplates in the region of the Banda Sea has formed an arcuate, west-dipping subduction zone, the Ceram-Timor trough (McCaffrey, 1996). Again, contemporary deformation in this region is highlighted by an abundance of seismic activity.
Figure II-34 Geology of Study Area (from the EBLS Study of PT. Geobis Woodward Clyde Indonesia, 1998)
2.1.7.2 Morphology and Slope
Based on the topographic forms and slopes, features in the Berau/Bintuni Bay area and its surroundings can be classified into four morphological units:
• Plains Morphology. The plains morphology encompass most of the Berau/Bintuni Bay region including the North Plains. The slope ranges between 0° to 5°. In general, the area consists of alluvial channel deposits, floodplain deposits and littoral marine deposits.
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• Undulating Topography. The morphological unit is mainly found in isolated pockets located in alluvial plains, particularly formed from riverine deposition. The slope is from 5° to 10° with average elevation of relief around 30 m. • Low Hill Topography. This topography can be found in the western part of the Bomberai Plain, the northern part of the North Plain, and the edge of Onin Peninsula. The slope ranges between 10° to 20° with elevation of relief up to 100 m. • Hill Topography. The morphological unit may be encountered in part of the Onin Peninsula area with slope gradient over 20°.
2.1.7.3 Local Stratigraphy
Most of the study area in Teluk Berau/Bintuni consist of unconsolidated Quaternary alluvial and littoral deposits, particularly in physiography area. The Bomberai Plains and North Plains. On the other hand, the uplands of Onin Peninsula expose Cenozoic age carbonate and terrigenous clastic rocks of the New Guinea Limestone Supergroup. Older stratigraphic units, at least upper Paleozoic in age, have been detected by measurement tools in the region are Permian age coal- bearing lagoonal siliclastic rocks of the Aifam Group. These rocks are unconformably overlain by Mesozoic carbonate and siliclastic rocks.
The younger rocks in this succession probably belong to the Jass Formation, a sequence of shales and claystones that become more calcareous towards the top of the sequence. Rock types exposed in the study area include rocks belonging to the Tertiary New Guinea Limestone Supergroup (Baham and Onin Formations) and the Upper Miocene - Pleistocene Steenkool Formation and Pleistocene Tusuawai Sandstone. The rock formations, from oldest to most recent, are as follows:
• New Guinea Supergroup – Baham Formation. The Paleocene age Baham Formation comprises marine sedimentary rocks, primary sandstone, glauconite, biomycrite, and bicalcarenite (predominantly carbonate and glauconite rock). These rocks outcrop on the east-central portion of Onin Peninsula, within the hanging wall of the Onin thrust.
• New Guinea Supergroup – Onin Formation. This formation comprises predominantly marine limestones, marls, calcareous siltstone, and sabkha carbonates (dolomite). This formation outcrops over the majority of Onin Peninsula.
• Steenkool Formation. This formation consists of siltstones, mudstones, and sandstones. These rocks are fluvial, deltaic, swamp, lagoonal, and estuarine deposits containing minor amounts of conglomerate and lignite. The Steenkool Formation is located on the southern side of Berau/Bintuni Bay.
• Tusuawai Sandstone. This formation consists of sandstone and shale, with only minor occurance in the eastern part of the North Plain physiography.
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• Weriagar Plains Group. This group comprises sands, clays, and silts, deposited in swamp, floodplain, fluvial, estuarine, and littoral environments from the quarter period. Deposits of this formation cover much of the North Plain and Bomberai Plain physiography.
2.1.7.4 Local Geological Structure
Berau/Bintuni Bay is separated from Cenderawasih Bay (also known as Geelvink Bay) on the eastern part of North Papua by the Jakati-Jamur fault zone as shown in Figure II-35. The fault zone extends in the north-south direction through the region connecting the Bird’s Head (known as “Bird’s Neck”), to the Masikeri Highlands in the Lenggoru Fault Belt (commonly spelled “Lengguru”). More detailed description on this fault and other primary faults accompanying lateral movement are shown in section 5.2 (“Tectonic Regions of Papua”) of the report on Seismic Hazard Assessment in the Tangguh LNG Project (EQE International, 1999). The report discusses the Sorong, Ransiki, Yapen, and Tarera-Aiduna faults in the western part of Papua, all of which are identified as active faults in a study made in 1978. This report also discusses collision zones and uplift of earth’s crust in the Lenggoru Fold Belt and Seram Trench and New Guinea trench fault.
The oldest Stilata in the Berau/Bintuni Bay region is‘Permian’ age (290 – 251 million years old) coal-bearing lagoonal siliclastic rock. .
This Stilata is founded on carbonate rocks and siliclastic from the Mesozoik period. Drilling in Berau/Bintuni bay indicates that the age of the Mesozoik strata is highly varied along a series of fault blocks. The age of the strata varies between the Early to middle Jurassic (208 to 160 million years ago) to Late Cretaceous (97-66 million years ago). Overall, this discussion conforms to the assessment result using radar satellite imagery above the Bird’s Head region conducted by Koopmans (1986). Using remote sensing technique, Koopmans was able to describe four main structural units of geological regions of northern Papua, namely:
a. Paleozoic age igneous – metamorphic complex (known as the Kemoem Formation); b. Mesozoic age central vogelklop monocline; c. Late Mesozoic age Lengguru folded belt; and d. Berau-Bintuni Basin (classified by Koopmans as part of the large Bomberai Basin, and classified in Mesozoic period).
In summary, it may be concluded that the Berau/Bintuni Bay region is located in a relatively stable block of the earth’s crust in the bay area. To the north, the bay is bordered by W-NW striking and Sorong lateral-right fault zone; to the east by fold and Lenggoru thrust belt heading north; to the south by the Tarera-Aiduna fault; and to the west by the Seram-Timor Trench (PT Geobis Woodward-Clyde Indonesia, 1998).
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2.1.7.5 Earthquake and Tsunami As the Berau/Bintuni Bay study area is located in one of the most active tectonic regions in the world, although actually Berau/Bintuni bay itself extends in a relatively stable block of the earth’s crust, the study area may generally be categorized as an earthquake vulnerable area. The study area is located between New Guinea fault-trench to the north and the Seram-Timor Trench to the south. The folds and trench zone is a collision and subduction zone, both of which are historical sources of destructive earthquakes. Global seismology database belonging to the National Earthquake Information Center (NEIC), U.S. Geological Survey, presents information on earthquakes occurring in the Papua region during the past 170 years (1830 to the present). The files combined with data from the International Seismological Center (ISC), indicate that between the year 1830 to 1998 there were 3,951 earthquake incidents with strength above 2.0 in the rectangular area measuring 10° x 7° around the Tangguh LNG project site (EQE International, 1999). Coordinates used for the data base search were 128°E - 138°E and 1°N - 6°S. As the acceptable limit for earthquake strength for engineered structures commonly used is scale 5.0, the number of earthquake events occurring in the scale is around 1,052 events that may potentially destroy engineered struct ures in the rectangular area 10° x 7° (EQE International, 1999).
Figure II-35 Geological Sketch Map of the Bird’s Head Region, Irian Jaya (Papua) (Redrawn from Erftemeijer et al. [1989] After Audretsch et al. [1966]
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Figure II-36 plots the centers of earthquake events recorded only in the rectangular area 5° x 3° in the vicinity of the Tangguh LNG project site (PT. Calmarine/Emcon, 1999). It may be observed from this plot that several earthquake events of strength 5.0 have occurred near the project site, although earthquakes of strength 6.0 or over are known not to have happened in a radius of less than 100 km from the planned project site. Based on this information and various other data, computer simulation by EQE International (1999) indicated that the rectangular area is characterized by rather steep gradient of peak ground acceleration (PGA) hazard, namely above 0.4 g at return period of 475 years, east of Berau/Bintuni Bay at position of approximately 133°20' E. The results show that the Tangguh LNG project site is in Zone 3 classification for buildings with ordinary structure according to the 1994 U.S. Uniform Building Code. Zone coefficient is roughly equivalent to ground acceleration with median probability of 10% to be exceeded in a 50 year period. The risk level is related to median return period of 475 years. Figure II-37 shows values of PGA calculation for structures built on soft rock; the Figure shows that calculated values for structures built on hard soil will be slightly higher.
Figure II-36 Locations of Earthquake in Irian Jaya (Papua) Recorded by the U.S./Geological Survey, National Earthquake Information Center (From: PT. Calmarine/Emcon, 1977)
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Figure II-37 Grid Map of Median Value of 475 Years Peak Ground Acceleration (PGA) of Soft Rock in One Square Degree Around the LNG Site (From: EQE International, 1999)
In a supplementary report (EQE International, 2000), it was described that the site for construction of LNG jetty was estimated to be vulnerable to the danger of soil movement, with ground acceleration value of 0.27 g in return period of 475 years.
A further report presented horizontal and vertical ground acceleration movement for the proposed facility site plan of LNG Plant and also for points at 2 km intervals along the proposed pipeline installation from the offshore construction site of Wiriagar and Vorwata to the site of the LNG jetty.
Deep sea seismic activities that can potentially affect the project site consist of the Seram and New Guinea subduction zones. Furthermore, four offshore shallow faults in Simuri (Saengga) waters will have an influence on the project site. All the faults extend a distance of 1 km to the Northeast. Not even one of the four faults disturb the sea bed, although one of them has apparently penetrated the surface of the sea bed. It is estimated that the fault is not seismogenic and limited to shallow ground column. With regard to the factor of earth crust dimension required for an active seismogenic fault, the length of surface fracture is generally greater than 1 km (EQE International, 2000).
In the region around the Bird’s Head, West Papua, based on NEIC-USGS records the number of earthquake incidents recorded from 1973 to August 2007 was 18,504 incidents with strength interval ranging from 2.9 – 8.3 SR. In this year’s interval , two earthquakes occurred in very strong category, i.e. over 8 SR as shown in Figure II-38.
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Figure II-38 Earthquake Distribution from 1973 – 2007
From USGS records, four earthquakes occurred in 2012. On May 31st, 2012, a 5.5 SR earthquake struck at depth of 17.5 km. Then, on June 1st, another earthquake was recorded of 5.7 SR at depth 14.3 km. On June 5th, 2012, yet another earthquake of 4.7 SR at depth 20.9 km, and finally on June 7th, 2012, a 4.7 SR earthquake at depth 41 km. The earthquake epicenters were in close proximity to one another. The four earthquakes were in the zone at distance of 80 – 100 km west of Manokwari city.
Tsunamigenic sources in the study area are limited to earthquakes occurring along the Ceram subduction zone. Most tsunamis, which could affect the project site, would arise from the Ceram-Banda Seas, however there is the potential for tsunamigenic events to be occured from closer sources. Risk associated with tsunamis include the following:
• Srended boat during low water elevations is associated with the retreating phase of the tsunamic wave;
• Reverse dynamic interaction between floating structures and fixed structures over a short period so that waves strike with extremely high energy; • Failure to establish a safe non-operating configuration, and/or evacuate personnel from lower elevations and platforms.
Calculations results of a study on the probability of tsunami hazard at specific sites in Berau/Bintuni Bay (EQE International, 2001) indicated the possibility and potential impact of tsunami on the Tangguh LNG project site, so it should be
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essential to conduct an investigation on early warning system of local tsunami hazards.
2.1.8 Water Quality
Environmental baseline data collecting of water quality within the study area boundaries is performed for three types of waters, namely River, Nearshore, and Offshore.
2.1.8.1 River Water Quality
River water sampling was performed during the dry season (July – August 2012) and wet season (March – April 2013). Samples were taken from the Saengga River on the western boundary of the Tangguh LNG (SW-1) with coordinates 02° 27’ 59.8” S - 133° 06’ 16.2 “ E and from Senindara River, east of the Tangguh LNG location ( SW-3) with coordinates 02° 31’ 54.8” S - 132° 16’ 29.3 “ E (Map II-11). Tidal condition during sampling is shown in Figure II-39 – Figure II-40. River water sampling during the dry season at SW-1 coincided with the period approaching high tide, while at SW-3 it coincided with the period approaching lowest tide.
Figure II-39 Tidal Condition during Dry Season Sampling ( August 9th, 2012)
Wet season sampling at SW-1 coincided with the period of lowest tide, while at SW- 3 it coincided with the period approaching highest tide.
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Figure II-40 Tidal Condition during Wet Season Sampling (March 12th, 2013)
Figure II-41 Tidal Condition during Wet Season Sampling ( March 17th, 2013)
The tabulation of river water quality analysis result can be seen in Table II-29 for the fresh water quality and Table II-30 for estuarine river water, while the certificate of the laboratory analysis results can be seen in Appendix II-1.
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Table II-29 Laboratory Analysis Results of River Water Quality (Fresh Water Properties)
Water Quality SW-1 No. Parameter Unit Standard Class II2 Wet Season Physical Test 1 pH1) - 6 - 9 6.45 2 Temperature1) oC ± 3 26.3 3 Total Dissolved Solids , TDS mg/L 1,000 70 4 Total Suspended Solids, TSS mg/L 50 129 Anion 1 Chloride, Cl mg/L - 33.0 2 Fluoride, F mg/L 1,5 <0,02
3 Sulfate, SO4 mg/L - 7
4 Sulfide as H2S mg/L 0.002 <0.002 5 Total Cyanide, CN mg/L 0.02 <0.005 Nutrient
1 Free Ammonia , NH3-N mg/L - <0.02
2 Nitrate, NO3-N mg/L 10 0.019
3 Nitrite, NO2-N mg/L 0.06 <0.001 4 Total Phosphor , P mg/L 0.2 0.101 Microbiological Test 1 E.Coli MPN/100ml 1000 40 2 Total Coliform MPN/100ml 5000 326 Dissolved Metals 1 Arsenic, As mg/L 1 0.0013 2 Barium, Ba mg/L - <0.1 3 Boron, B mg/L 1 <0.1 4 Cadmium, Cd mg/L 0.01 <0.005 5 Chromium Hexavalent, Cr6+ mg/L 0.05 <0.002 6 Cobalt, Co mg/L 0.2 <0.02 7 Copper, Cu mg/L 0.02 <0.01 8 Iron, Fe mg/L - 0.29 9 Lead, Pb mg/L 0.03 0.002 10 Manganese, Mn mg/L - 0.05 11 Mercury, Hg mg/L 0.002 <0.00005 12 Selenium, Se mg/L 0.05 <0.0005 13 Zinc, Zn mg/L 0.05 0.020 Others
1 Biochemical Oxygen Demand, BOD5 mg/L 3 6 2 Chemical Oxygen Demand, COD mg/L 25 28
3 Chlorine, Cl2 mg/L 0,03 <0.01 4 Dissolved Oxygen, DO 1) mg/L 4 5.23 5 Oil & Grease mg/L 1 <1 6 Surfactane, MBAS mg/L 0.2 <0.01
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Water Quality SW-1 No. Parameter Unit Standard Class II2 Wet Season 7 Phenol Compound, as Phenol mg/L 0.001 <0.001 Source : Primary data, Measurement Results of the Lab Intertek, 2012 -2013 Note : 1) Insitu measurement 2) The quality standard in accordance with Government Regulation No. 82 Year 2001, Class II
Table II-30 Laboratory Analysis Results of River Water Quality* (Estuarine Water Properties) SW-1 SW-3 No. Parameter Unit Dry season Dry season Wet season Physical Test 1 pH1) - 7.4 6.9 7.18 2 Temperature1) oC 26.2 27.9 29.7 3 Total Dissolved Solids, TDS mg/L 27,700 33,200 23,400 4 Total Suspended Solids, TSS mg/L 51 33 45 Anion 1 Chloride, Cl mg/L 13,800 12,600 11,700 2 Fluoride, F mg/L 0.47 0.54 0.30
3 Sulfate, SO4 mg/L 1,860 1,860 1,790
4 Sulfide as H2S mg/L <0.002 <0.002 <0.002 5 Total Cyanide, CN mg/L <0.005 <0.005 <0.005 Nutrient
1 Free Ammonia , NH3-N mg/L <0.02 <0.02 <0,02
2 Nitrate, NO3-N mg/L 0.078 0.081 0.344
3 Nitrite, NO2-N mg/L 0.010 0.030 0.022 4 Total Phosphor , P mg/L 0.074 <0.005 0.021 Microbiological Test 1 E.Coli MPN/100ml 47 201 23 2 Total Coliform MPN/100ml 1550 >2,420 345 Dissolved metal 1 Arsenic, As mg/L 0.0012 0.0007 0.0022 2 Barium, Ba mg/L <0.1 <0.2 <0.1 3 Boron, B mg/L 3.7 3.3 3.4 4 Cadmium, Cd mg/L <0.0001 <0.005 <0.005 5 Chromium Hexavalent, Cr6+ mg/L <0.002 <0.002 <0.002 6 Cobalt, Co mg/L <0.02 <0.02 <0.02 7 Copper, Cu mg/L <0.01 <0.01 <0.01 8 Iron, Fe mg/L <0.05 <0.05 <0.05 9 Lead, Pb mg/L <0.001 <0.001 <0.001 10 Manganese, Mn mg/L 0.030 0.03 0.01 11 Mercury, Hg mg/L <0.00005 <0.00005 <0.00005 12 Selenium, Se mg/L <0.0005 <0.0005 <0.0005
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SW-1 SW-3 No. Parameter Unit Dry season Dry season Wet season 13 Zinc, Zn mg/L 0.017 0.009 0.007 Others Biochemical Oxygen Demand, 1 mg/L <2 <2 <2 BOD5 Chemical Oxygen Demand, 2 mg/L <2 11 5 COD
3 Chlorine, Cl2 mg/L <0.01 <0.01 <0.01 4 Dissolved Oxygen, DO 1) mg/L 4.18 3.2 3.97 5 Oil & Grease mg/L <1 <1 <1 6 Surfactane, MBAS mg/L <0.01 <0.01 <0.01 7 Phenol Compound, as Phenol mg/L <0.001 <0.001 <0.001 Source: Primary data, Measurement Results of the Lab Intertek, 2012 -2013 Note: 1) in situ measurement * Due to river water at SW-1 during dry season sampling , and at SW-3 both during dry and wet season were indicated as sea water quality, thus the results of the analysis in this case were neither compared with fresh water nor seawater quality standard since this is a transition zone.
In accordance with Government Regulation No. 82 Year 2001, the water encompasses all water above and below ground surface, except sea water and fossil water. Rivers that flow into Bintuni Bay are influenced strongly by tides, which during the dry season the sea water influence could reach several kilometers from the estuary. While during the wet season, sea water could be fresh water. In accordance with the provisions of Article 55 in Government Regulation No. 82 Year 2001: “in the event that water quality standard at the water source has not yet or has not been established, water quality criteria for Class II will apply”.
A water body can be classified on the basis of salinity according to the Venice System (1958) as shown in Table II-31 (Reid, 1961). Mixture of sea water and river water can cause changes to the cation and anion composition or water chemistry composition. The degree of seawater intrusion is usually measured from the amount of water salinity or TDS value. Seawater salinity generally ranged between 33 to 380/00 or average 350/00. While average fresh water salinity was 0,650/00 (Reid, 1961).
Table II-31 Classification of Water Body Based on Salinity* and TDS
Zone Salinity (0/00) TDS (mg/L) **) Hyperhaline >40 >40,800 Euhaline 40 – 30 40,800 – 30,600 Mixohaline 30 – 0.5 30,600 – 510 Mixoeuhaline >30 however < around Euhaline >30,600 however < around Euhaline (Mixo-)polyhaline 30 – 18 30,600 – 18,360 (Mixo-)mesohaline 18 – 5 18,360 – 5,100 (Mixo-)oligohaline 5 – 0.5 5,100 – 510 Limnetic <0.5 <510
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Note : 0 *) Salinity 1 /00 ≈ 1,020 mg/L TDS assuming that water density equals 1.02 kg/m3 Source: Reid, 1961
The value of TDS could be associated with water salinity, in which 10/00 salinity is equivalent to TDS 1,000 mg/L. In accordance with the Venice System (1958) criteria, Saengga River water at sampling location of SW-1 during the dry season was considered as brackish water (TDS 27,700 mg/L), and in the zone of (Mixo-) polyhaline, while in the wet season it was considered as fresh water (TDS 70 mg/L). Saengga River at location SW-1 was fresh water during the wet season, this is likely due to: (1) sampling at location SW-1 coinciding with lowest tide as shown in Figure II-41, (2) seawater intrusion in the wet season did not reach SW-1, as the river water current was quite strong and entered the Bintuni Bay.
River water at sampling location of SW-3 ( Senindara River) during the dry season was considered in Euhaline zone (TDS 33,200 mg/L) and during the wet season was considered in (Mixo-)polyhaline zone (TDS 23,400 mg/L).
The dominant influence of seawater in the two rivers , is shown by the high chloride and sulfate contents. Average chloride and sulfate content in seawater are respectively 19,300 mg/L and 2,700 mg/L (Anderson, 2008). Chloride content in locations of SW-1 and SW-3 in the dry season are respectively 13,800 mg/L, 12,600 mg/L and at SW-3 in the wet season is 11,700 mg/L. Similarly, sulfate content at SW-1 and SW-3 in the dry season is 1,860 mg/L and in the wet season is 1,790 mg/L. The high concentrations of chloride and sulfate indicate that the estuary of the river is greatly influenced by seawater intrusion.
Based on theabove and definition of water in accordance with Government Regulation No. 82 Year 2001, only river water in SW-1 in the wet season can be compared with Class II of water quality standard in accordance with Government Regulation No. 82 Year 2001, while in SW-1 and SW-3 in the dry season and SW-3 in wet season cannot be compared with fresh water quality standard since its quality approaches sea water quality.
In general, the water quality at SW-1 in the wet season (Table II-31) meets Class II of the water quality standard, except for the following parameters: TSS, BOD5, COD. Relative high concentration of TSSwas detected due to heavy rain occurred prior to surface water sampling. High concentration of TSS (129 mg/L) indicates the amount of sediment material carried by rainwater runoff. The TSS quality standard is 50 mg/L.
Swamp and mangrove forest bed contain large amount of dissolved organic compounds as well as in colloid form (humic compound) as the result of plants decomposition. Much evidence shows that humic compounds found in water (characterized by reddish brown water) are similar to those found in soils (Schnitzer, 1972). Swamp and mangrove forest are quite dominant in the study area,
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which those are found in watersheds of Saengga and Senindara. Based on the above, rainwater runoff will carry the natural organic compounds into river waters that will cause relatively high BOD5 and COD content (COD = 28 mg/L and BOD = 6 mg/L: COD Standard is 25 mg/L and BOD5 is 3 mg/L). Excess organic matter content in water can decrease DO, since dissolved oxygen in water will be used by bacteria to oxidize organic substances (DO at SW-1 during wet season was detected at 5,23 mg/L, DO standard is 4 mg/L). Optimum oxygen content in fresh water at temperature of 27 oC and pressure of 1 atmosphere is around 7,8 mg/L.
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Map II-12 Sampling Locations of River Water Quality
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2.1.8.2 Groundwater Quality
Groundwater quality sampling was performed by taking water samples from community wells in the villages of Tanah Merah Baru (TMB) and Saengga, the nearest villages to the Tangguh LNG. The sampling was carried out in the dry season (July 2012) and wet season (March 2013). Information on the location and code of groundwater samples is shown in Table II-32, while sampling locations are shown in Map II-2. Community wells which the water samples were taken are shallow wells, with the exception of a well in Saengga (DGW 01) which is a bore well.
Groundwater quality of the samples were compared with Class I water quality classification (drinking water quality) of Government Regulation No. 82 Year 2001 regarding Water Quality Management and Water Pollution Control.
Laboratory analysis results of groundwater quality are shown in Table II-32 and Table II-33, while the certificate can be found in Appendix II.
Generally the shallow groundwater quality of GW 01 and GW 02 (at Tanah Merah Baru) met the quality standard, except for parameters pH, and total coliform. Similarly, shallow groundwater quality of SGW 01 and SGW 02 (at Saengga village) generally met the quality standard except for parameters pH, fecal coli, total coliform. In general, deep groundwater quality (bore well , DGW 01) met quality
standard in effect, with the exception of nitrite as N (N-NO2).
Table II-32 Groundwater Sampling
Sampling Point Coordinates Wet Location Dry season Code South East season DGW 01 Saengga village 020 27' 59.8" 1330 06' 16.2" √ √ SGW 01 Saengga village 020 28' 18.1" 1330 06' 14.9" √ √ SGW 02 Saengga village 020 28' 09.9" 1330 06' 23.7" √ √ GW 01 TMB village 020 27' 25.0" 1330 06' 44.3" √ √ GW 02 TMB village 020 27' 29.4" 1330 06' 53.1" √ √
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Table II-33 Laboratory Analysis Results of Groundwater Quality Water DGW 01 SGW 01 SGW 02 GW 01 GW02 No. Parameter Unit Quality standard Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Physical 1 Temperature °C ± 3 25.0 26.9 26.1 27.3 25.8 26.9 24.6 26.4 24.7 24.7 2 Total Dissolved Solids, TDS mg/L 1500 344 381 25 23 20 17 89 179 15 15 Inorganic Chemical 1 pH mg/L 6.0 – 9.0 7.93 8,32 5.51 5.39 5.24 5,95 5.75 7.14 5.79 5.79
2 Nitrate, N-NO3 mg/L 10 0.463 0.045 <0.005 0.170 0.010 <0,005 8.63 0.223 1.45 1.45 3 Arsenic mg/L 0.05 <0.0005 0.0010 0.0006 0.0014 0.0007 0,0005 <0.0005 0.0010 <0.0005 <0.0005 4 Selenium mg/L 0.01 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <0,0005 <0.0005 <0.0005 <0.0005 <0.0005
5 Cadmium mg/L 0.01 <0.0001 <0.0001 <0.0001 <0.0001 0.0001 <0,0001 0.0002 <0.0001 <0.0001 <0.0001
6 Chromium Hexavalent mg/L 0.05 <0.002 <0.002 <0.002 <0.002 <0.002 <0,002 <0.002 <0.002 <0.002 <0.002
7 Copper mg/L 0.02 <0.01 0.02 <0.01 <0.01 <0.01 <0,01 <0.01 <0.01 <0.01 <0.01 8 Iron mg/L 0.3 <0.05 0.10 0.170 0.26 0.060 0,16 <0.05 <0.05 0.08 0.08 9 Lead mg/L 0.03 <0.001 0.004 <0.001 0.001 <0.001 <0,001 0.002 <0.001 <0.001 <0.001 10 Manganese mg/L 0.1 0.03 0.05 <0.01 0.01 0.03 0,03 0.03 <0.01 <0.01 <0.01
11 Mercury mg/L 0.001 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0,00005 <0.00005 <0.00005 <0.00005 <0.00005
12 Zinc mg/L 0.05 0.016 0.036 0.012 0.009 0.015 0,010 0.017 0.008 0.013 0.013
13 Chloride mg/L 600 3.4 1.0 3.8 4.7 2.6 2,7 6.9 23.8 2.6 2,6
14 Cyanide mg/L 0.02 <0.005 <0.005 <0.005 <0.005 <0.005 <0,005 <0.005 <0.005 <0.005 <0.005
15 Fluoride mg/L 0.5 0.02 <0.02 <0.02 <0.02 <0.02 <0,02 0.04 <0.02 <0.02 <0.02
16 Nitrite, N-NO2 mg/L 0.06 1.37 0.765 <0.001 <0.001 <0.001 <0,001 <0.001 <0.001 <0.001 <0.001 17 Sulfate mg/L 400 <2 <2 3 4 3 3 <2 <2 <2 <2 18 Sulfide mg/L 0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0,002 <0.002 <0.002 <0.002 <0.002 Microbiological
1 Fecal Coliform MPN/100 mL 100 TTD 2 1 7 13 128 TTD TTD 1 1
2 Total Coliform MPN/100 mL 1,000 179 187 99 548 225 >2,420 4 14 1,410 1,410 Organic Chemical 1 MBAS mg/L 0.2 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 Source : Primary data, Measurement results of Intertek Lab 2012 -2013 Note : 1) insitu measurement 2) Quality standard based on PP 82 of 2001, Class I (as Drinking Water Standard)
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Map II-13 Sampling Locations of Groundwater Quality
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Figure II-42 Locations of Shallow Wells and Bore Wells in Saengga
Deep Groundwater Based on analysis of deep groundwater, it was evident that parameters analyzed generally met the quality standard. Several parameters were in fact not detected. Only nitrite parameter did not meet the quality standard. Nitrite concentration of water samples from deep well (DGW 01 in Saengga village) was 1.37 mg/L in the dry season, while in the wet season it was 0.765 mg/L. Quality standard of nitrite for water quality classification Class I was 0.06 mg/L, however for conventional drinking water treatment, N-NO2 is allowed to be smaller than 1 mg/L. The high nitrite concentration is likely caused by decomposition of organic substances into ammonia that will further become nitrite (by nitrification bacteria), the next process will likely not take place, i.e nitrite will not become nitrate as groundwater is in semi aerobic (suboxic) condition. Another possibility is that nitrate present in groundwater is denitrified by denitrification bacteria and the process does not continue from nitrite into free nitrogen.
High nitrite concentration at DGW1 Station is a natural condition and is not related to the operated Tangguh LNG activities. This is based on the following: a) Community Well Quality Out of the five samples taken from community wells, Nitrite value exceeded the quality standard is only from DGW1 Station. It is a Deep Well with depth of 150 m approximately located in Saengga village. The other stations are shallow wells and based on analysis the Nitrite values met the quality standard. TDS value at DGW1 station (344 and 381 mg/L) had characteristic that differed from TDS of other wells, i.e. 13 - 179 mg/L
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Figure II-43 Groundwater Quality Mapping of Community Wells (Baseline Study for AMDAL of the Tangguh LNG Expansion)
b) Operational Activities of the Tangguh LNG
There is no impact from the Tangguh LNG operational activities toward deep groundwater quality. Operational activity of the Tangguh LNG with potential impact on shallow groundwater quality is non-hazardous waste disposal site facility (non-hazardous waste Landfill). This facility is equipped with impermeable material (HDPE) and leachate management system. The leachate is drained to Sewage Treatment Plant and the treated wastewater is discharged into sea at -13 m LAT (located at LNG Jetty 1). There are several monitoring wells around the non-hazardous waste landfill location. Routine analysis is carried out to monitor groundwater quality around the non-hazardous waste landfill location.
Groundwater quality monitoring results at the monitoring wells around the landfill location did not indicate the existence of Nitrite concentration exceeded the applicable groundwater quality standard. This can be seen in Figure II-44.
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Figure II-44 Nitrite Concentration in the Monitoring Wells around the Non- Hazardous Waste Landfill Location
Total Dissolved Solids (TDS) in deep water were detected in amount of 344 mg/L in the dry season and 381 mg/L in the wet season, although the figure is still far below quality standard, i.e. 1,500 mg/L, however it appears slightly higher compared with shallow groundwater. The slightly high TDS in deep water likely originates from limestone (calcium and carbonate ions) characterized by pH of water that is slightly alkaline (7.93 - 8.32). Besides, slightly high TDS in deep water in Saengga village was not caused by dissolved chloride and sulfate ions (as indication of the presence or absence of seawater intrusion), in which the two anions were detected very low, i.e. chloride 1.0 – 3.4 mg/L and sulfate <2 mg/L. This indicated that deep well water in Saengga village does not experience seawater intrusion.
Shallow Groundwater Based on laboratory analysis results, in general shallow groundwater quality met the quality standard. Several parameters were in fact not detected. Only parameters of pH, fecal coliform and total coliform did not meet the quality standard.
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The pH values of shallow groundwater ranged between 5.24 – 5.51 in the dry season and 5.39 - 5.95 in the wet season in Saengga location. The pH value in TMB location ranged between 5.75 – 5.79 in the dry season and 5.08 – 7.14 in the wet season. The quality standard of pH is between 6 – 9. In general, pH of shallow groundwater tends to be acid, this is likely due to the acidic condition of the local soil (pH value of H2O around 3.8 – 5.0) or simultaneously due to humic compounds (particularly fulvic acid) from decomposition of litteron the forest bed entering shallow groundwater.
Fecal coliform in SGW-02 was detected at 128 MPN/100 mL. It did not meet quality standard of 100 MPN/100mL. Fecal coli is a bio-indicator of polluted water by human and/or mammals (Homoiterm) faeces. High fecal coli was originated from public toilet (MCK) location in the proximity of wells. This was due to no walls constructed in the wells, so that contaminated rainwater by human faeces infiltrated the well water.
Total coliform refers to all types of bacteria coli that can be bio-indicators since these can survive longer than fecal coliform. Total coliform is a bio-indicator of water pollution by mammals. Total coliform did not meet quality standard in location of SGW 02 in the wet season, i.e. >2,420 MPN/100 mL and in location of GW 02 in the dry season (1,420 MPN/100 mL ) and the wet season (1,410 MPN/100 mL). The quality standard for total coliform is 1,000 MPN/100 mL. The amount of total coliform indicated that well water in SGW 02, and GW 02 was contaminated by human or mammal activities.
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Figure II-45 Graph of Groundwater Physical Parameters
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Figure II-46 Graph of Inorganic and Organic Groundwater Parameters
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Iron
Manganese Mercury
Figure II-47 Graph of Groundwater Dissolved Metals Parameters (1)
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Figure II-48 Graph of Groundwater Dissolved Metals Parameters (2)
Figure II-49 Graph of Groundwater Microbiological Parameters
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2.1.8.3 Seawater Quality
In general, Bintuni Bay indicates its water quality characteristic as estuary waters with high sediment and organic content derived from swamps and mangroves entering the bay waters through rivers. Seawater quality is in accordance with Minister for the Environment Decree No. 51 Year 2004 regarding Seawater Quality Standard, Appendix III Seawater Quality Standard for Marine Biota. Since mangrove forest is quite dominant in Bintuni Bay and there are no coral reef and seagrass fields found in the waters of Bintuni Bay, so that several water quality parameters such as Total Suspended Solids (TSS), temperature and salinity are compared with water quality standard for mangrove.
Nearshore and offshore seawater sampling were conducted in during dry season (July – August 2012) and wet season (March – April 2013). Sampling locations encompassed most of Bintuni Bay (Table II-34 and Figure II-50). Tidal conditions during sampling are shown in Figure II-50 for the dry season and Figure II-51 for the wet season. The certificate of laboratory analysis results is shown in Appendix II-1 and Appendix II-2.
Table II-34 Sample Codes and Seawater Sampling Location
Sample Coordinates Remark Code South East Nearshore NS-01 020 39' 32.3" 1320 32' 18.9" Waters around Arguni NS-02 020 38' 09.0" 1320 05' 31.0" Waters around Saengga NS-03 020 25' 49.6" 1330 07' 18.0" Waters to the north of Tangguh LNG NS-04 020 25' 13.2" 1330 10' 51.9" Waters to the east of Tangguh LNG NS-05 020 27' 53.3" 1330 19' 55.5" Waters around Wimbro and Sidomakmur Waters at the easternmost end of Bintuni Bay NS-06 020 22' 19.9" 1330 49' 15.8" (Reference) NS-07 020 13' 43.3" 1330 15' 00.9" Waters around Sorondauni NS-08 020 17' 19.0" 1320 52' 49.1" Waters around Weriagar NS-09 020 18' 25.9" 1320 39' 43.4" Waters around Kalitami Offshore OS-01 020 20' 32.0" 1320 57' 31.0" Waters around WD Platform OS-02 Waters at the westernmost end of Bintuni Bay 020 24' 42.0" 1320 32' 43.0" (Reference) OS-03 020 41' 50.3" 1320 44' 40.4" Waters at north of Goras OS-04 020 34' 28.5" 1320 39' 05.2" Waters around UBA Platform OS-05 020 20' 44.0" 1320 48' 39.0" Waters at south of Mogotira OS-06 020 30' 42.2" 1320 58' 32.2" Waters around KKA Platform OS-07 020 26' 01.4" 1330 01' 22.9" Waters around OFA Platform Waters around Platform VRC and eastern OS-08 020 18' 58.0" 1330 08' 17.0" disposal area OS-09 020 22' 36.0" 1320 06' 39.0" Waters around ROA Platform
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Sample Coordinates Remark Code South East Waters between the Tangguh LNG and VRB OS-10 020 22' 52.0" 1330 11' 47.0" Platform OS-11 020 15' 54.0" 1330 11' 07.0" Waters between VRC and VRA Platforms OS-12 Waters between TTA, VRF, VRB, and VRD 020 19' 22.0" 1330 17' 19.0" Platforms OS-13 020 20' 06.0" 1330 26' 20.0" Waters at eastern of Bintuni Bay OS-14 Waters at the easternmost end of Bintuni Bay 020 21' 16.0" 1320 41' 00.0" (Reference)
July 29th, 2012 August 3th, 2012
August 4th, 2012 August 5th, 2012
August 7th, 2012 August 13th, 2012
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October 27th, 2012 Figure II-50 Graph of Tidal Conditions during Dry season Sampling
March 15th, 2013 March 16th, 2013
March 17th, 2013 March 23rd, 2013
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March 24th, 2013 April 23rd, 2013
April 24th, 2013 April 25th, 2013
April 26th, 2013 Figure II-51 Graph of Tidal Conditions during Wet season Sampling
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Map II-14 Locations of Nearshore and Offshore Seawater Sampling
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Nearshore Seawater Quality Analysis results of nearshore seawater quality are shown in Table II-36 and Figure II-53 to Figure II-59. Based on the analysis results, the nearshore seawater quality generally met seawater quality standard (Seawater Quality Standard in accordance with Minister of the Environment Decree No. 51 Year 2004, Appendix III: Seawater Quality Standard for Marine Biota. Several parameters of seawater quality such as sulfide, total cyanide, ammonia, BOD5, oil and grease, total phenol, surfactane (MBAS), PAH; and chromium hexavalent dissolved metal, lead, mercury as well as nickel were not detected (below equipment’s detection limit) at all sampling locations both in dry season and wet season. Some other dissolved metals such as arsenic, cadmium, copper and zinc were detected at several sampling locations with very low concentrations and the values far below the threshold limits of quality standard for the metals. Several parameters that did not meet the quality standards were TSS, turbidity, nitrate, phosphor and DO. TSS concentration that did not meet quality standard were observed in NS-02 (near the estuary of Saengga river) and NS-05 (near the estuary of Senindara river) in the dry season with respective concentrations of 193 mg/L and 86 mg/L. The high TSS concentration in NS-02 and NS-05 locations was due to the proximity of the locations to the coast dominated by mangrove and near the river estuary carrying sediments to Bintuni Bay. Sampling from the two locations were taken at the time approaching high tide, which the current flowed from west to east. Based on field records during sampling, there was rain in the both locations prior to sampling.
Periodically, once a week, concentrations of TSS are monitored by the Tangguh LNG at water intake for desalination water in the LNG Jetty 1. Monitoring results during 2011 (47 monitoring data) are shown in Table II-35 and Figure II-52. Based on the monitoring results, during dry season, TSS concentration ranged between 32 mg/L to 267 mg/L with average value of 102 mg/L, while during wet season the range was between 23 mg/L to 369 mg/L with average of 139 mg/L. From 47 monitoring data of TSS, a total of 27 data or 57% of TSS monitoring results exceeded quality standard for mangrove, namely the required quality standard for TSS parameter ≤80 mg/L. This indicated that naturally the TSS concentration in nearshore activities locations was sufficiently high.
Table II-35 TSS Concentration at Water Intake in LNG Jetty 1 during 2011 Dry season Wet season Date TSS (mg/L) Date TSS (mg/L) 06-07-2011 32 5-1-2011 46 13-07-2011 71 12-1-2011 126 20-07-2011 138 19-1-2011 256 27-07-2011 140 26-1-2011 103 03-08-2011 39 2-2-2011 28 10-08-2011 65 9-2-2011 61 17-08-2011 88 16-2-2011 23 31-08-2011 187 23-2-2011 93 07-09-2011 267 30-2-2011 82
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Dry season Wet season Date TSS (mg/L) Date TSS (mg/L) 14-09-2011 71 2-3-2011 139 21-09-2011 52 9-3-2011 229 28-09-2011 51 16-3-2011 60 05-10-2011 44 23-3-2011 289 12-10-2011 82 30-3-2011 71 19-10-2011 228 6-4-2011 88 26-10-2011 35 13-4-2011 256 09-11-2011 85 27-4-2011 266 16-11-2011 75 4-5-2011 168 30-11-2011 194 11-5-2011 68 18-5-2011 369 25-5-2011 34 8-6-2011 129 15-6-2011 38 29-6-2011 32 7-12-2011 233 14-12-2011 252 23-12-2011 255 28-12-2011 100 Source: Primary data, Tangguh LNG. Weekly Periodic Monitoring Results.
a
b
Figure II-52 Graph of TSS Concentration at Water Intake, Jetty LNG 1 in 2011. (a) Dry season, (b) Wet season
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Turbidity in most of nearshore sampling locations was observed in the range of 7.7 to 183 NTU did not meet the quality standard, both in the wet season and dry season. Except in monitoring location of NS 01 (around Arguni) during the dry season turbidity was detected at 0.2 mg/L, and the turbidity in NS-07 (around Sorondauni) and NS-08 (around Weriagar) during the wet season were 1.8 NTU and 3.9 NTU respectively. The quality standard for turbidity is <5 NTU. The high turbidity level in the Bintuni Bay waters was in line with the high concentrations of TSS and low water clarity. The water clarity during the wet season and the dry season at nearshore and offshore sampling locations measured using Secchi Disk, was mostly observed less than 1 m, with the exception of the waters around Arguni (monitoring location of NS 01) in the dry season with clarity reaching 3 m. Seawater quality standard for Marine Biota in Minister of the Environment Decree No. 51 Year 2004, stipulates water clarity for coral reef is greater than 5 m, for seagrass is more than 3 m, while water clarity for mangrove is unlimited.
The low clarity figure in the waters of Bintuni Bay, prevent coral reef and seagrass from developing well, as proven by the absence of coral reef and seagrass in Bintuni Bay. Both of the marine biota require sufficient light to be able to develop, besides they are highly sensitive to high sedimentation level (TSS).
Nitrate and phosphor in seawater are nutrients required for marine primary production. Growth of phytoplankton is determined by the molarity ratio of N and P. Analysis result of N and P ratio globally for estuary and coastal aquatic ecosystem is <16:1, and could reach 100:1 for high sea (Downing, 1997). Average concentration of N in seawater is 0.8 mg/L and P is 0.07 mg/L (Korte, 1977).
Nitrogen compounds dominant in seawater is nitrate (NO3), and for phosphor compound is ortho-phosphate (PO4). The analysis result of nitrate as N and phosphate as P in nearshore waters indicated values around 0.045 mg/L – 0.203 mg/L, and <0.005 – 0.076 mg/L respectively. Data of the analysis results indicated that nitrogen compound as N in nearshore of Bintuni Bay was in low category as it was much smaller than 0,8 mg/L, while phosphate compound as P was also low <0,07 mg/L except for the observation point of NS 02 in the dry season that was detected at 0.076 mg/L. Calculation result indicated that ratio of N:P nearshore of Bintuni Bay ranged between 3:1 to 9:1. Ratio of N:P <16:1 indicated constraint of one of the elements in seawater besides nitrogen in marine waters productivity (Downing, 1997).
Phosphor is an essential chemical element in marine primary production. The ratio of phosphor to other elements in the aquatic ecosystem is smaller than in living organisms. Phosphor is a limiting nutrient in eutrophication (process of developing nutrient-rich waters); meaning that although seawater has high concentrations of nitrate, eutrophication will not occur with low amounts of phosphate. The presence of phosphate in water greatly affects marine ecosystem balance. When phosphate content as P in water is low (<0.01 mg/L), growth of algae will be hindered, a condition known as oligotrophic (nutrient-poor waters). On the other hand, when phosphate content is high followed by balanced nitrogen compounds, growth of
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algae will be unlimited, a condition known as eutrophy, or nutrient-rich waters (http://id.wikipedia.org/wiki/Wikipedia_bahasa_Indonesia).
Concentration of N-nitrate in nearshore waters during the wet season and the dry season ranged between 0.045 – 0.228 mg/L and P-phosphate ranged between <0.005 – 0.076 mg/L. Based on the range values, generally nutrient concentration (N-nitrate and P-phosphate) in the waters of Bintuni Bay cannot be considered high yet; besides due to the ratio N:P in nearshore waters of Bintuni Bay <16:1, then it can be concluded that nutrient content of waters is not optimal yet. This is supported by observation results of phytoplankton in nearshore waters, which Cyanophyceae was only represented by one genus namely Trichodesmium. Trichodesmium is a member of the Cyanobacteria class with filament and commonly found in nutrient- poor marine waters.
Seawater quality standard in accordance with Minister of the Environment Decree No. 51 Year 2004 for Nitrate as N is 0.008 mg/L and for total phosphate as P is 0.015 mg/L. Empirically, according to Korte (1977) in marine waters, nitrogen content (0.8 mg/L) is far higher than phosphor content (0.07 mg/L) or nitrogen content of ten times higher than phosphor. In fact, according to Downing (1997) nitrogen content in offshore waters could be 100 times higher than phosphor content. On the other hand, the quality standard of Minister of the Environment Decree No. 51 Year 2004 specifies lower nitrogen content than phosphor content, or nitrogen content two times lower than phosphor content. Therefore, the quality standard determining threshold limits for N and P in Minister of the Environment Decree No. 51 Year 2004, does not accord with the above limits.
In general, concentration of DO in the dry season and wet season in all sampling locations met quality standard, with concentration of DO observed >5 mg/L, except at NS 06 (the waters in the easternmost part of Bintuni Bay as a reference location) in the dry season and wet season the DO concentration was slightly lower than the threshold limit of 5 mg/L, i.e. respectively detected of 4.87 mg/L and 4.58 mg/L. The lower concentration of DO at location NS 06, was likely due to NS 06 is located at the eastern end of Bintuni Bay (mouth of the bay), which is subject to less tidal movement or the re-aeration process is not as great as that at the mouth of the bay.
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Table II-36 Analysis of Nearshore Marine Waters Quality NS 01 NS 02 NS 03 NS 04 NS 05 NS 06 NS 07 NS 08 NS 09 No. Parameter Unit standard* Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Physical 1 Clarity1) m * 3 2.0 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 2,5 <1 2.0 <1 1,1 Floating 2 - nil nil nil Nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil Objects 1) 3 Odor1) - Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural 4 Oil Layer 1) - nil nil nil Nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil 5 pH1) - 7 -8.5 7.89 8.06 7.89 7.89 7 7.88 7,75 7.87 8.54 7.78 7.22 7.37 7.94 7.92 7.73 8.07 7. 96 8,15 6 Salinity1) ‰ Natural** 32.1 27.2 30.0 25.9 24 26.2 30,0 26.1 31 26.4 24.4 21.5 29.2 24.0 14.2 26.2 26.7 28,5 7 Temperature1) oC Natural*** 28.4 30.2 28.7 31.5 29 30.4 30,1 31.1 31.1 30.2 28.6 30.4 28.6 31.4 27.3 31.6 27.0 30,5 Total 8 Suspended mg/L **** 5 11 193 51 22 47 43 44 86 46 60 19 20 17 33 11 28 15 Solids, TSS 9 Turbidity 1) NTU < 5 0.2 171 138 46.3 49.5 40.1 36.7 28.7 60.0 26.8 49.4 12.2 11.8 1.8 35.2 3.9 27.0 7,7 Anion
1 Sulfide, H2S mg/L 0.01 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 Total Cyanide, 2 mg/L 0.5 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 CN Nutrient Ammonia, 1 mg/L 0.3 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 NH3-N
2 Nitrate, NO3-N mg/L 0.008 0.065 0.073 0.064 0.081 0.120 0.119 0.170 0.090 0.078 0.112 0.288 0.045 0.165 0.109 0.156 0.121 0.203 0.065 Phosphor Total, 3 mg/L 0.015 <0.005 0.015 0.076 0.040 0.034 0.036 0.015 0.027 0.046 0.030 0.038 0.017 <0.005 0.018 <0.005 0.014 <0.005 0.017 P Microbiological 1 Total Coliform MPN/100mL 1000 4 2 TTD TTD 4 11 TTD TTD TTD TTD TTD TTD TTD TTD 33 TTD 49 TTD Dissolved Metals 1 Arsenic, As mg/L 0.012 0.0005 0.0016 0.0011 0.0012 0.0015 0.0015 0.0007 0.0009 0.0021 0.0015 <0.0005 0.0009 0.0008 0.0012 0.0008 0.0006 0.0006 0.0015 2 Cadmium, Cd mg/L 0.001 0.0005 <0.0005 0.0001 <0.0005 <0.0001 <0.0005 0.0001 <0.0005 <0.0001 <0.0005 0.0001 <0.0005 0.0001 <0.0001 0.0012 <0.0001 0.0001 <0.0001 Chromium 3 Hexavalent, mg/L 0.005 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 Cr6+ 4 Copper, Cu mg/L 0.008 <0.001 <0.001 <0.001 0.002 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 0,001 <0.001 0.001 <0.001 <0.001 <0.001 5 Lead, Pb mg/L 0.008 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 6 Mercury, Hg mg/L 0.001 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 7 Nickel, Ni mg/L 0.05 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.001 <0.02 <0.02 <0,02 <0.02 0.001 <0.02 <0.001 <0.02 <0.001 8 Zinc, Zn mg/L 0.05 0.009 <0.005 0.010 0.008 0.008 <0.005 0.008 <0.005 <0.005 <0.005 0.014 <0.005 0.008 <0.005 0.007 <0.005 0.006 <0.005 Others Biochemical 1 Oxygen mg/L 20 <2 <2 2 <2 <2 <2 <2 <2 2 <2 <2 <2 4 <2 <2 <2 2 <2 Demand, BOD5 Dissolved 2 mg/L >5 5,.40 5.85 5.95 5.30 5.16 5.60 6.04 5.49 5.16 5.03 4.87 4.58 6.04 6.08 6.12 5.99 6.33 6.47 Oxygen, DO 1) Surfactane, 3 mg/L 1 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 MBAS 4 Oil and Grease mg/L 1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 Total Phenol 5 mg/L 0.002 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Compound Organic Polycyclic Aromatic 1 mg/L 0.003 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.00001 <0.0001 <0.00001 <0.0001 <0.00001 Hydrocarbon, PAHs Source: Primary data, Lab Intertek measurement 2012 -2013 * for coral reef >5 m, for seagrass >3 m, mangrove unlimited Note: ** Change allowed until <5% average seasonal salinity 1) in-situ Measurement *** Change allowed until <2 oC of natural temperature 2) Minister of the Environment Decree No. 51 Year 2004, Appendix III: Seawater **** for coral reef: 20 mg/L, seagrass: 20 mg/L; mangrove: 80 mg/L Quality Standard for Marine Biota
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Figure II-53 Graph of Seawater Physical Parameters (Nearshore)
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Figure II-54 Graph of Seawater Chemical Parameters (Nearshore) (1)
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Figure II-55 Graph of Seawater Chemical Parameters (Nearshore) (2)
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Figure II-56 Graph of Seawater Chemical Parameters (Nearshore) (3)
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Figure II-57 Graph of Seawater Dissolved Metals Parameters (Nearshore) (1)
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Figure II-58 Graph of Seawater Dissolved Metals Parameters (Nearshore) (2)
Figure II-59 Graph of Seawater Microbiological Parameters (Nearshore)
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Offshore Seawater Quality The analysis results of offshore seawater quality are shown in Table II-37 and Figure II-60 to Figure II-66. Based on the analysis results, offshore seawater quality generally met quality standard. Several parameters of seawater quality , i.e. sulfide, total cyanide, ammonia, BOD5, oil and grease, total phenol, surfactane (MBAS), PAH; as well as chromium hexavalent dissolved metals, copper, lead, mercury and nickel were not detected (below instrument detection limit) in all sampling locations, in the dry season and wet season. Other dissolved metals such as arsenic, cadmium and zinc were detected in several sampling locations with very low concentrations and with far lower value than threshold limits of quality standard for the dissolved metals.
Similar to nearshore waters, except TSS, seawater quality parameters that did not meet quality standard were turbidity, nitrate, phosphor and DO.
Turbidity of offshore seawater in all sampling locations during the dry season ranged between 1.5 to 10.9 NTU. Sampling location OS 09 (waters around ROA platform), OS 10 (waters between Tangguh LNG and VRB platform) and OS 14 (at the easternmost end of Bintuni Bay, reference point) had a turbidity value exceeding threshold limit (quality standard <5 NTU) with turbidity values of 10.1 NTU, 10.9 NTU and 8.4 NTU detected respectively. While during the wet season, turbidity ranged between 1.2 to 379 NTU. Sampling location OS 03 (waters at north of Goras), OS 06 (waters around KKA platform) and OS 14 (at the easternmost end of Bintuni Bay, reference point) had turbidity values > 5 NTU, i.e. 187 NTU, 379 NTU and 16.3 NTU detected respectively. Extreme high water turbidity at OS 03 and OS 06 were likely due to the higher concentration of TSS in both of the sampling locations (TSS at OS 03 was detected 25 mg/L and at OS 06 was detected 20 mg/L) that were relatively higher than other sampling locations.
The phenomena of nitrogen compound as N and phosphate compound as P in offshore waters of Bintuni Bay were similar to nearshore waters. The analysis results of nitrate as N and phosphate as P in the dry and wet seasons in offshore waters indicated a range of values between 0.015 – 0.231 mg/L for N, and between <0.005– 0.046 mg/L for P. The analysis data indicated that nitrogen compound as N in offshore waters of Bintuni Bay was categorized as low since it was smaller than 0.8 mg/L, while phosphate compound as P was also categorized as low since it was <0,07 mg/L except at observation points of OS 03 and OS 04 in the dry season that were detected at 0.128 mg/L and 0.323 mg/L respectively. The calculations showed that the ratio of N:P for offshore waters of Bintuni Bay ranged between 3:1 to 5:1. The ratio of N:P <16:1 indicated a constraint in one of the elements of seawater besides nitrogen in seawater productivity (Downing, 1997).
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In offshore waters during the wet season and dry season, N-nitrate ranged between 0.019 -0.231 mg/L and P-phosphate ranged between <0.005 – 0.128 mg/L. Based on the range of values, generally the concentration of nutrients (N-nitrate and P- phosphate) in Bintuni Bay waters cannot be considered high yet; besides due to the ratio N:P in offshore waters of Bintuni Bay was <16:1, then it can be concluded in terms of nutrient-rich waters it was not optimal yet. This was supported by observation results of phytoplankton in offshore waters, similar to nearshore waters, which Cyanophyceae was only represented by one genus namely Trichodesmium. Trichodesmium is a member of the Cyanobacteria class with filament and commonly found in nutrient-poor seawater. The phenomena of nitrogen and phosphor concentrations in offshore waters of Bintuni Bay was similar to that of nearshore waters.
In general, the concentration of DO in the dry season and wet season in all sampling locations met quality standard, with concentration of DO observed > 5 mg/L, except at location OS 09 (in the waters around ROA platform) during the dry season the concentration of DO was slightly lower than the threshold limit of 5 mg/L, i.e. 4.86 mg/L (nonetheless the value of DO cannot be considered low).
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Table II-37 Analysis of Seawater Quality Offshore OS1 – OS7 Quality OS 01 OS 02 OS 03 OS 04 OS 05 OS 06 OS 07 No. Parameter Unit standard* Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Physical 1 Clarity1) m * 3.0 4.0 4.0 6.0 2.0 2.0 5.0 10.0 3.0 3.5 3.0 1.5 3.0 4.0 2 Floating Objects1) - nil nil nil nil nil nil nil nil nil Nil Nil Nil nil nil nil 3 Odor1) - Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural 4 Oil Layer1) - nil nil nil nil nil nil nil nil nil Nil Nil nil nil nil nil 5 pH1) - 7 -8.5 8 7.86 8 7.9 8.61 8.04 8.63 7.9 8 7.86 8.58 8.04 8.55 7.94 6 Salinity1) ‰ Natural** 31 27.7 31 28.9 31.1 25.4 31,9. 29.2 30 27.6 31.2 27.1 31.2 26.1 7 Temperature1) oC Natural*** 28 29.5 28 29.8 30.2 29.9 29.8 30.8 29 30.5 30.1 30,2 30.1 31.1 8 Total Suspended Solids, TSS mg/L **** 2 6 2 4 8 25 11 6 4 3 12 20 11 9 9 Turbidity 1) NTU < 5 3.6 1.8 4 1.9 3.9 187 1.5 1.2 2.4 1.5 2.1 379 4.7 1,5 Anion
1 Sulfide, H2S mg/L 0.01 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 2 Total Cyanide, CN mg/L 0,5 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 Nutrient
1 Ammonia, NH3-N mg/L 0.3 <0.02 <0.02 <0,02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02
2 Nitrate, NO3-N mg/L 0.008 0.080 0.031 0.091 0.019 0.033 0.051 0.051 0.015 0.087 0.030 0.033 0.072 0.049 0.030 3 Total Phosphor , P mg/L 0.015 0.010 0.018 <0.005 0.017 0.128 0.016 0.323 0.020 0.005 0.018 0.046 0.025 0.043 0.021 Microbiological 1 Total Coliform MPN/100mL 1000 TTD 2 TTD TTD TTD TTD TTD TTD TTD TTD TTD TTD TTD TTD Dissolved metals 1 Arsenic, As mg/L 0.012 0.0007 0.0011 0.0011 0.0011 0.0018 0.0011 0.0018 0.0010 0.0006 0.0010 0.0015 0.0011 0.0018 0.0008 2 Cadmium, Cd mg/L 0.001 0.0001 <0.0001 0.0003 <0.0001 <0.0001 <0.0005 <0.0001 <0.0001 0.0006 <0.0001 <0.0001 <0.0005 <0.0001 <0.0001 3 Chromium Hexavalent, Cr6+ mg/L 0.005 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 4 Copper, Cu mg/L 0.008 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 5 Lead, Pb mg/L 0.008 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0,001 6 Mercury, Hg mg/L 0.001 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 7 Nickel, Ni mg/L 0.05 <0.02 <0.001 <0.02 <0.001 <0.001 <0.02 <0.001 <0.001 <0.02 <0.001 <0.001 <0.02 <0.001 <0.001 8 Zinc, Zn mg/L 0.05 0.008 <0.005 0.007 <0.005 <0.005 <0.005 <0.005 <0.005 0.007 <0.005 <0.005 <0.005 <0,005 <0.005 Others
1 Biochemical Oxygen Demand, BOD5 mg/L 20 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 2 Dissolved oxygen, DO 1) mg/L >5 6.17 5.33 5.70 5.70 5.88 5.95 5.35 6.86 5.68 6.17 5.33 5.97 5.81 6.22 3 Surfactane, MBAS mg/L 1 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 4 Oil and Grease mg/L 1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 5 Total phenol Compound mg/L 0.002 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Organic 1 Polycyclic Aromatic Hydrocarbon, PAHs mg/L 0.003 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 1) In-situ measurement 2) Minister of the Environment Decree No. 51 Year 2004, Appendix III: Quality Standard of Seawater for Marine Biota * For coral reef >5 m, seagrass >3 m, unlimited for mangrove ** Change allowed up to <5% average seasonal salinity *** Change allowed up to <2 oC of normal temperature **** For coral reef: 20 mg/L, seagrass: 20 mg/L; mangrove: 80 mg/L
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Table II-38 Analysis Offshore Seawater Quality OS8 – OS14
Quality OS 08 OS 09 OS 10 OS 11 OS 12 OS 13 OS 14 No Parameter Unit standard Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Physical 1 Clarity1) m * 4.0 4.0 2.0 3.0 2.0 3.0 3.0 5.0 3.0 5.0 2.0 5.0 1.0 0.8 2 Floating Objects1) - nil nil nil nil nil Nil nil nil nil nil nil nil nil nil nil 3 Odor1) - Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural Natural 4 Oil Layer1) - nil nil nil nil nil Nil nil nil nil nil nil nil nil nil nil 5 pH1) - 7 -8.5 7.63 7.94 7.70 7.93 7.75 7.90 7.97 7.89 7.64 7.92 7.60 7.8 7.50 7.58 6 Salinity1) ‰ Natural** 29.80 26.1 30.40 26.7 29.97 28.7 30.30 27.4 29.93 27.7 29.63 28.8 28.0 21.9 7 Temperature1) oC Natural*** 28.90 31.1 28.70 31.0 28.97 29.9 28.20 30.5 28.93 31.3 29.00 29.9 28.5 31.3 8 Total Suspended Solids, TSS mg/L **** 7 9 11 6 18 3 9 6 10 9 17 5 19 30 9 Turbidity 1) NTU < 5 4,2 1.5 10.1 1.4 10.9 2.6 2,4 0.6 3.3 0.5 5,4 < 0.5 8.4 16.3 Anion
1 Sulfide, H2S mg/L 0.01 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 2 Total Cyanide, CN mg/L 0.5 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 Nutrient
1 Ammonia, NH3-N mg/L 0.3 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02
2 Nitrate, NO3-N mg/L 0.008 0.179 0.030 0.121 0.030 0.149 0.034 0.126 0.035 0,.59 0.029 0.180 0.029 0.231 0.110 3 Total Phosphor , P mg/L 0.015 <0.005 0.021 <0.005 0.019 <0.005 0.028 <0.005 0.021 0.006 0.021 <0.005 0.023 <0.005 0.024 Microbiological 1 Total Coliform MPN/100mL 1000 TTD TTD TTD TTD TTD 23 TTD TTD TTD TTD TTD TTD TTD TTD Dissolved metals 1 Arsenic, As mg/L 0.012 0.0009 0.0008 0.0007 0.0010 0.0005 0.0018 0.0008 0.0018 0.0006 0.0018 0.0007 0.0013 0.0005 0.0012 2 Cadmium, Cd mg/L 0.001 0.0001 <0.0001 0.0001 <0.0001 0.0001 <0.0001 0.0001 <0.0001 0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0005 3 Chromium Hexavalent, Cr6+ mg/L 0.005 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 4 Copper, Cu mg/L 0.008 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 5 Lead, Pb mg/L 0.008 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 6 Mercury, Hg mg/L 0.001 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 <0.00005 0.00014 <0.00005 <0.00005 7 Nickel, Ni mg/L 0.05 <0.02 <0.001 <0.02 <0.001 <0.02 <0.001 <0.02 <0.001 <0.02 <0.001 <0.02 <0.001 <0.02 <0.02 8 Zinc, Zn mg/L 0.05 0.006 <0.005 0.006 <0.005 0.006 <0.005 0.005 <0.005 0.007 <0.005 0.007 <0.005 0.009 <0.005 Others
1 Biochemical Oxygen Demand, BOD5 mg/L 20 2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 2 <2 2 Dissolved oxygen, DO 1) mg/L >5 5.94 6.22 4.86 6.58 5.13 5.57 5.85 6.12 5.35 6.71 5.13 6.36 5.13 4.85 3 Surfactane, MBAS mg/L 1 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 4 Oil and Grease mg/L 1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 5 Total phenol mg/L 0.002 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Organic Polycyclic Aromatic Hydrocarbon, 1 mg/L 0.003 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 PAHs 1) In-situ measurement 2) Minister of the Environment Decree No. 51 Year 2004, Appendix III: Quality Standard of Seawater for Marine Biota * For coral reef >5 m, for seagrass >3 m, unlimited for mangrove **Change allowed until <5% average seasonal salinity *** Change allowed until <2 oC of normal temperature **** for coral reef: 20 mg/L, seagrass: 20 mg/L; mangrove: 80 mg/L
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Figure II-60 Graph of Physical Seawater Parameters (Offshore)
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Figure II-61 Graph of Chemical Parameters of Marine Waters (Offshore) (1)
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Figure II-62 Graph of Chemical Parameters of Marine Waters (Offshore) (2)
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Figure II-63 Graph of Dissolved Metals Parameters of Marine Waters (Offshore) (1)
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Figure II-64 Graph of Chemical Parameters of Marine Waters (Offshore) (3)
Figure II-65 Graph of Dissolved Metals Parameters of Marine Waters (Offshore) (2)
Figure II-66 Graph of Microbiology Parameters of Marine Waters (Offshore)
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Nitrate and Phosphate concentrations of Bintuni Bay during environmental baseline study for AMDAL of the Tangguh LNG Development are provided in Figure II-67 and Figure II-68.
Figure II-67 Seawater Quality Mapping in Bintuni Bay (Baseline Study for AMDAL of the Tangguh LNG Expansion)
Figure II-68 Seawater Nitrate Concentrations in Bintuni Bay (Baseline Study for AMDAL of the Tangguh LNG Expansion)
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Figure II-69 Regional Condition in the Vicinity of Station NS 6 and OS 14
From the above analysis results, the following were discovered: a) Concentrations of Nitrate and Phosphate were high in all monitoring stations. Concentration of Nitrate at nearshore locations (river estuaries) tended higher than at offshore locations b) Concentrations of Nitrate and Phosphate at eastern of Bintuni Bay were high, i.e. at observation stations of NS 6 and OS 14 in the waters nearby Nature Reserve of Bintuni Bay approximately 80 km from the Tangguh LNG site. The Nature Reserve is a protected area and there are no large scale activities in its onshore area (see Figure II-69) c) High concentrations of Nitrate and Phosphate in Bintuni Bay was a natural condition
2.1.8.4 Wastewater Quality of the Current Tangguh LNG Operations
The ongoing operations activities of the Tangguh LNG consist of two LNG trains (LNG Train 1 and LNG Train 2) to process feedgas derived from 14 production wells at two offshore platforms (VRA and VRB). The types of wastewater being managed during operations of the Tangguh LNG include: • Produced water;
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• Hydrocarbon contaminated water; • Chemically contaminated wastewater; • Desalination water; and • Domestic wastewater.
The wastewater as mentioned above is treated prior to discharge overboard at the current outfall in LNG jetty at -13 m LAT. Further description of wastewater management can be seen in Chapter I of ANDAL sub chapter 1.2.3 LNG Plant activities section C7 Wastewater Management. Wastewater quality monitoring is routinely performed in accordance with provisions in the Integrated AMDAL of the Tangguh LNG that was approved in 2002 and the Wastewater Discharge Permit No.125 Year 2013 issued by Minister of the Environment. Routine monitoring results are shown in Figure II-70 to Figure II-75. a) Produced Water Quality Produced water quality from the Produced Water Treatment during 2011 – 2013 met quality standards in accordance with the permit, except ammonia parameter. Figure II-70 shows that ammonia concentration several times exceeded quality standard, however referring to the Wastewater Discharge Permit No. 125 Year 2013, the compliance for wastewater discharge to seawater was made toward quality standard and/or maximum load of the wastewater. The load calculation towards ammonia parameter in produced water still below the maximum load of produced water. The produced water quality can be seen in Figure II-70 to Figure II-75 as follows.
Figure II-70 COD Concentrations in Produced Water 2011-2013
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Figure II-71 Oil and Grease Concentrations in Produced Water 2011-2013
Figure II-72 H2S Concentration in Produced Water 2011-2013
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Figure II-73 Concentration and Load of NH3N in Produced Water 2011-2013
Figure II-74 Concentration of Total Phenol in Produced Water in 2011-2013
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Figure II-75 Concentration of Methanol in Produced Water 2011-2013
b) Hydrocarbon Contaminated Water Hydrocarbon contaminated water is treated in CPI (Corrugated Plate Interceptor) to reduce the hydrocarbon content. The effluents of CPI are then flown to produced water tank to be treated together with produced water. There is no discharge of hydrocarbon contaminated water treated by CPI directly into the sewerage system (discharge pipelines). c) Chemically Contaminated Wastewater Chemically contaminated wastewater quality during 2011 to 2013 met applicable quality standard as shown in Figure II-76 to Figure II-768.
Figure II-76 Concentration of COD in Chemically Contaminated Wastewater in 2011-2013
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Figure II-77 Concentration of TSS in Chemically Contaminated Wastewater in 2011-2013
Figure II-78 Concentration of Total Toxic Metals in Chemically Contaminated Wastewater in 2011-2013
d) Desalination Wastewater (Brine Water Reject) Desalination wastewater monitoring only included pH and salinity in accordance with the Wastewater Discharge Permit Number 125 Year 2013 issued by Ministry of the Environment which the quality met the applicablestandard
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e) Domestic Wastewater (Sewage) Domestic wastewater treated in Sewage Treatment Plant (STP) is routinely monitored by an accredited laboratory in accordance with the quality standard specified in the Watewater Discharge Permit Number 125Year 2013 issued by Ministry of the Environment. The monitoring results are presented in Figure II- 79 to Figure II-81 as follows:
Figure II-79 BOD Concentration in Domestic Wastewater in 2011-2013
Figure II-80 Concentrations of Oil and Grease in Domestic Wastewater 2011- 2013
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Figure II-81 Concentration of TSS in Domestic Wastewater 2011-2013
2.1.9 Sediment
Sea bed sediment quality samples were taken in nearshore and offshore waters of Bintuni Bay. The sampling locations were the same as seawater quality sampling locations and conducted twice, i.e in the dry season and wet season.
In the dry season between the months of August – October 2012, 11 sediment samples were taken in offshore areas (OS) and nine sediment samples in nearshore (NS) areas; while in the wet season between March – April 2013, 14 sediment samples were taken in offshore (OS) and eight samples in nearshore (NS) areas. River sediment sampling was done in the dry season and wet season with respectively two samples taken. Locations of sediment sampling were the same as those for water quality and benthos as shown in Table II-34 and Map II-13.
So far, Indonesia does not have a sediment quality standard determining the threshold limits of sediment quality. For this purpose, ANZECC Interim Sediment Quality Guidelines (ANZECC-ISQG) Sediment Criteria has become the reference in discussion of sediment quality since West Papua lies in the Australasia ecoregion (Figure II-82). The criteria consists of Upper Limit and Lower Limit, as shown in Table II-39. In the study, concentrations of heavy metal in sediment analyzed consist of antimon, cadmium, chromium, copper, lead, mercury, nickel, silver, zinc and arsenic in accordance with the ANZECC-ISQG Sediment Quality Criteria. Selenium parameter was also analyzed , however using Sediment Quality Criteria based on Van Derveer and Canton (1997) with lower limit of 1 mg/kg and upper limit 4 mg/kg.
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Figure II-82 Australasia Ecoregion
Table II-39 Criteria of Sediment Quality Based on ANZECC-ISQG Sediment Quality Criteria Heavy Metals (mg/kg) ISQG Lower Limit ISQG Upper Limit Antimony (Sb) 2 25 Cadmium (Cd) 1.5 10 Chromium (Cr) 80 370 Copper (Cu) 65 270 Lead (Pb) 50 220 Mercury (Hg) 0,15 1 Nickel (Ni) 21 52 Silver (Ag) 1.0 3.7 Zinc (Zn) 200 410 Arsenic (As) 20 70 Selenium (Se)* 1 4 * Selenium content based on Van Derveer and Canton (1997), with lower limit 1 mg/kg and upper limit 4 mg/kg.
Analysis results of heavy metals in sediment are shown in full in Table II-41 and Table II-42 (Offshore), Table II-43 (nearshore) and Table II-44 (River). Figure II-85 and Figure II-86 (Offshore), Figure II-87 and Figure II-88 (Nearshore) and Figure II-89 and Figure II-90 (River) show the graph of heavy metals content in sediment compared with the ANZECC-ISQG Sediment Quality Criteria, while Figure II-91 depicts the range , median value using Whisker graph for each parameter according to sediment sampling location, i.e. offshore, nearshore and river.
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2.1.9.1 Seabed Sediment of Offshore
Antimony (Sb) In the dry season, concentrations of Sb ranged between 0.01 to 1.8 mg/kg. From 11 sampling locations, OS-01 approximately 10 km offshore Weriagar to the southeast or approximately 2 km south of the proposed location of WDA offshore gas platform (offshore platform to be built in initial phase development) has the highest sampling value (1.8 mg/kg) or approaching the lower limit of sediment criteria determined in ANZECC-ISQG, i.e. 2 mg/kg. The lowest value of Sb concentration is <0.01 originating from three sampling locations, namely OS-03, OS-08 and OS- 10.
In the wet season, concentrations of Sb ranged between 0.12 to 1.7 mg/kg. Out of the 14 sampling locations, OS-06 which lies some 6 km offshore of Onar Baru to the west or at position of approximately 1 km northeast of the proposed offshore platform KKA (the offshore platform to be built in further phase development in the future) was the sampling location with highest value of Sb (1.7 mg/kg) or approaching the lower limit of sediment criteria as determined in ANZECC-ISQG, of 2 mg/kg.
Arsenic (As) During the dry season, arsenic concentrations range between 4.2 to 86.9 mg/kg. From 11 sampling locations, two locations have the highest figure. High values are found for arsenic of 86.9 mg/kg at location OS-06 approximately 6 km offshore of Onar Baru to the west and the figure exceeds the sediment criteria as determined in ANZECC-ISQG, i.e. 70 mg/kg (upper limit), while at location OS-09 in position of approximately 30 km offshore from Inanwatan to the south or some 57 km from Arguni to the northwest the value of arsenic reached 60.9 mg/kg or almost approaching the upper limit (70 mg/kg) and far exceeded the lower limit of 20 mg/kg.
Arsenic concentrations at seven other locations, namely OS-04, OS-12, OS-07, OS-08, OS-10, OS-01 and OS-14 exceeded the lower limit of 21 mg/kg, while in the two remaining locations, namely OS-03 and OS-11 with arsenic concentration values of respectively 4.2 mg/kg and 10.3 mg/kg, which are still below the lower limit of 20 mg/kg.
In the wet season, arsenic concentrations ranged between 3.8 – 94.4 mg/kg. From the 14 sampling locations, three sampling locations had values exceeding the upper limit of ANZECC-ISQG i.e. 70 mg/kg. The highest value of arsenic was 94.4 mg/kg in location OS-07 situated some 10 km west of Combo Dock, while the value of arsenic in location OS-09 (approximately 30 km offshore from Inanwatan to the south or some 8 km from the Tangguh LNG location) and OS-10 (some 9 km northwest of Combo Dock) were respectively 73.9 mg/kg and 71.02 mg/kg.
Arsenic concentrations in Bintuni Bay’s sediment during the environmental baseline study of AMDAL for the Tangguh LNG Expansion are shown in Figure II-83.
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Figure II-83 Mapping of Arsenic Concentration in sediment of Bintuni Bay (AMDAL Environmental Baseline Study of the Tangguh LNG Expansion)
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Figure II-84 Map of Sediment Sampling in Bintuni Bay (AMDAL Environmental Baseline Study of Tangguh LNG in 2002)
Table II-40 Summary of Several Types of Metals Concentration in the Sediment from the AMDAL Survey Team during the Dry season in 2000 (September - October 2000) Concentration (mg / kg) Element Average Maximum Average Standard Deviation Aluminum (Al) 6.,659 11,400 3,880 2,267 Iron (Fe) 33,893 49,600 9,310 10,348 Manganese (Mn) 1.048 3,290 69.4 731 Barium (Ba) 33 44 <20 9 Cobalt (Co) 15,2 20 6 3.6 Copper (Cu) 5,3 11.4 2.6 2.7 Chromium (Cr) 14 25 10 4 Cadmium (Cd) 0.2 0.7 <0.1 0.1 Mercury (Hg) 0.010 0.019 0.005 0.005 Lead (Pb) 19 30 10 5 Arsenic (As) 36 74 2 20 Nickel (Ni) 31.1 42.7 14.2 7.4 Silver (Ag) 0.7 1.5 <0.4 0.3
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From analysis and data presented above, the following were known: a) Concentrations of Arsenic in sediment of Bintuni Bay had high value in nearly at all offshore locations from the survey results of 2012 and 2013. b) Concentrations of Arsenic in sediment had high value, i.e. average value 36 mg/kg and maximum value 74 mg/kg in September - October 2000 long before Tangguh LNG commenced activities in the area. The survey activities were conducted as environmental baseline survey to prepare an AMDAL of the Tangguh LNG (currently in operation) in 2002. c) Arsenic concentrations in Bintuni Bay had sufficiently high value prior to the presence of the Tangguh LNG activities.
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Table II-41 Results of Heavy Metals Analysis in Seabed Sediment of OS 01 – OS 07 (Offshore) ANZECC Sediment Criteria Sampling Location No Heavy Metals Unit ISQG Lower ISQG Upper OS 01 OS 02 OS 03 OS 04 OS 05 OS 06 OS 07 K H K H K H K H K H K H K H 1 Antimony, Sb mg/dry kg 2 25 1.80 0.64 0.62 <0.01 0.34 0.29 0.75 0.86 0.64 1.74 0.97 0.98 2 Arsenic, As mg/dry kg 20 70 30.4 37.9 25.8 4.24 3.79 49.6 38.4 7.0 86.9 69.4 42.8 94.4 3 Cadmium, Cd mg/dry kg 1,5 10 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 4 Chromium, Cr mg/dry kg 80 370 20 16 9 22 24 20 16 14 13 24 18 26 5 Copper, Cu mg/dry kg 65 270 6.4 1.2 <0.2 3.7 3,9 2,1 <0.2 3,4 1,5 3.3 3,4 3,6 6 Lead, Pb mg/dry kg 50 220 20 13 12 11 8 15 11 11 24 19 18 28 7 Mercury, Hg mg/dry kg 0,15 1 0.032 0.008 0.006 0.032 0.018 0.023 0.005 0.022 0.015 0.008 0,.037 0.012 8 Nickel, Ni mg/dry kg 21 52 21.2 18.5 10,3 19.6 18.8 17.1 14.6 15.0 16.3 19.4 19.1 22.8 9 Selenium, Se mg/dry kg 1*) 4*) 0.21 0.03 <0.01 1.09 0.06 <0.01 0.04 0.08 <0.01 0.02 0.05 0.03 10 Silver, Ag mg/dry kg 1 3,7 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 1 <0.4 <0.4 11 Zinc, Zn mg/dry kg 200 410 53.5 42.9 26.8 46.4 48.7 35.3 36.8 44.2 37.0 56.1 42.1 67.2 Organic 1 TPH mg/dry kg 0,3 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 K : Dry season H : Wet season *) Van Derveer and Canton (1997).
Table II-42 Analysis of Heavy Metals in Seabed Sediment of OS 08 – OS 14 Offshore ANZECC Sediment Criteria Sampling location No Heavy Metals Unit ISQG Lower ISQG Upper OS 08 OS 09 OS 10 OS 11 OS 12 OS 13 OS 14 K H K H K H K H K H K H K H 1 Antimony, Sb mg/dry kg 2 25 <0.01 0.29 0.73 0.23 <0.01 0.69 0.98 0.12 0.84 0.44 0.71 0.48 0.48 2 Arsenic, As mg/dry kg 20 70 25.1 25.3 61.0 73.9 25.1 71.0 10.3 10.4 27.8 53.9 8.3 22.5 5.73 3 Cadmium, Cd mg/dry kg 1,5 10 <0.1 <0,1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 4 Chromium, Cr mg/dry kg 80 370 23 19 13 10 16 14 21 19 18 11 17 31 13.27 5 Copper, Cu mg/dry kg 65 270 3,6 6,2 1.7 0.2 2,9 4.3 10.0 8.1 5.1 0.3 5.3 13.4 4.85 6 Lead, Pb mg/dry kg 50 220 15 16 11 17 12 16 14 13 15 10 10 15 6.04 7 Mercury, Hg mg/dry kg 0.15 1 0.022 0.027 0.004 0.005 0.022 0.014 0.054 0.032 0.032 0.005 0.023 0.027 0.02 8 Nickel, Ni mg/dry kg 21 52 21.9 25.0 20.9 19.2 21.4 24.7 27.3 23.7 20.2 16,6 19.7 32.3 11.69 9 Selenium, Se mg/dry kg 1*) 4*) <0.01 0.11 0.07 <0.01 0.14 0.03 <0.01 0.08 <0.01 <0,01 0.33 0.36 0.06 10 Silver, Ag mg/dry kg 1 3,7 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 11 Zinc, Zn mg/dry kg 200 410 44.8 63.9 38.9 39.8 43.5 54.8 61.9 63.2 44.4 34.8 51.2 76.1 31.28 Organic 1 TPH mg/dry kg 0,3 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 <2 19 <2 K : Dry season H : Wet season *) Van Derveer and Canton (1997).
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Figure II-85 Graph of Heavy Metals Content in Seabed Sediment of Offshore Waters Compared with ANZECC-ISQG Sediment Quality Criteria
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Figure II-86 Graph of Heavy Metals Content in Seabed Sediment of Offshore Waters Compared with ANZECC-ISQG Sediment Quality Criteria (note : for Selenium based on Van Derveer and Canton) – Continued
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Table II-43 Results of Heavy Metals Analysis in Seabed Sediment (Nearshore) ANZECC Sediment Criteria Sampling location No Heavy Metals Unit ISQG ISQG Upper NS 01 NS 02 NS 03 NS 04 NS 05 NS 06 NS 07 NS 08 NS 09 Lower K H K H K H K H K H K H K H K H K H 1 Antimony, Sb mg/dry kg 2 25 0.17 0.29 0.38 0.15 0.81 0.22 0.70 <0.01 0.55 0.32 0.44 0.22 0.17 0.87 0.39 0.34 0.46 2 Arsenic, As mg/dry kg 20 70 7.0 11.6 4.5 7.81 60.00 9.7 14.4 8.25 6.22 17.7 6.8 8.09 9.19 17.1 9.1 9,57 9.7 3 Cadmium, Cd mg/dry kg 1,5 10 <0.1 <0.1 <0.1 0.000 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0,1 <0.1 4 Chromium, Cr mg/dry kg 80 370 8 30 15 19 28 26 25 17 20 34 14 34 37 22 15 27 29 5 Copper, Cu mg/dry kg 65 270 1.2 9.1 3.9 4,6 7.7 7,7 6.7 6.0 7.3 14.0 5.2 6.0 7.6 26.2 10.4 13.1 19.7 6 Lead, Pb mg/dry kg 50 220 0 13 7 7 12 11 12 12 9 16 7 6 6 18 11 11 15 7 Mercury, Hg mg/dry kg 0,15 1 0.007 0.037 0.019 0.024 0.026 0.037 0.024 0,036 0.019 0.026 0.012 0.016 0.020 0.077 0.025 0,040 0.049 8 Nickel, Ni mg/dry kg 21 52 3.8 28.9 12.5 18.2 29.7 25.0 21.5 18.2 17.9 34.6 13.2 46.4 44.8 23.9 16.3 27.2 27.4 9 Selenium, Se mg/dry kg 1*) 4*) 0.23 0.27 0.06 0.14 0.08 0.21 0.47 <0.01 0.09 0.35 0.07 0.07 0.01 0.30 <0.01 0,17 0.03 10 Silver, Ag mg/dry kg 1 3,7 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 <0.4 11 Zinc, Zn mg/dry kg 200 410 6.2 73.7 34.1 36.1 71.2 69.2 73.9 45.5 47.9 89.3 34.7 72.7 84.3 81.3 61.5 72.4 87.2 Organic 1 TPH mg/dry kg 0.3 13 9 <2 <2 <2 10 <2 <2 <2 22 <2 <2 <2 18 <2 <2 <2 K : Dry season H : Wet season *) Van Derveer and Canton (1997).
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Figure II-87 Graph of Heavy Metals Content in Seabed Sediment of Nearshore Waters Compared with Sediment Quality Criteria of ANZECC-ISQG
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Mercury
Figure II-88 Graph of Heavy Metals Content in Seabed Sediment of Nearshore Waters Compared with ANZECC-ISQG Sediment Quality Criteria(note : for Selenium based on Van Derveer and Canton) – Continued
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Table II-44 Results of Heavy Metals Analysis in Riverbed Sediment ANZECC Sediment Criteria Sampling Location No. Heavy Metals Unit ISQG Lower ISQG Upper SW 01 SW 03 K H K H 1 Antimony, Sb mg/dry kg 2 25 0.12 0.43 0.16 0.41 2 Arsenic, As mg/dry kg 20 70 21.5 13.7 5.10 13.8 3 Cadmium, Cd mg/dry kg 1.5 10 <0.1 <0.1 0.000 <0.1 4 Chromium, Cr mg/dry kg 80 370 24 30 4 31 5 Copper, Cu mg/dry kg 65 270 8.3 11.1 0.9 12.4 6 Lead, Pb mg/dry kg 50 220 7 12 2 17 7 Mercury, Hg mg/dry kg 0.15 1 0.020 0.029 0.004 0.035 8 Nickel, Ni mg/dry kg 21 52 34.7 30.7 5.7 36.3 9 Selenium, Se mg/dry kg 1*) 4*) 0.04 0.07 0.06 0.10 10 Silver, Ag mg/dry kg 1 3.7 <0,4 <0.4 <0.4 <0.4 11 Zinc, Zn mg/dry kg 200 410 64.9 75.7 12.5 91.1 Organic 1 TPH mg/dry kg 0.3 3 <2 <2 <2 K : Dry season H : Wet season *) Van Derveer and Canton (1997). K : Dry season H : Wet season *) Van Derveer and Canton (1997).
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Figure II-89 Graph of Heavy Metals Content in Riverbed Sediment Compared with ANZECC-ISQG Sediment Quality Criteria
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Figure II-90 Graph of Heavy Metals Content in Riverbed Sediment Compared with ANZECC-ISQG Sediment Quality Criteria (note : for Selenium based on Van Derveer and Canton) – Continued
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There were also five sampling locations which Arsenic value exceeded the ANZECC-ISQG lower limit of 20 mg/kg. The five locations are OS-06, OS-12, OS- 04, OS-02 and OS-08 with arsenic concentrations of respectively 69.4 mg/kg, 53.9 mg/kg, 38.4 mg/kg, 25.8 mg/kg and 25.3 mg/kg.
The remaining five locations had values below the lower limit set by ANZECC- ISQG of 20 mg/kg. The five locations i.e. OS-11, OS-13, OS-05, OS-14 and OS-03 had arsenic concentrations of respectively 10.36 mg/kg, 8.3 mg/kg, 6.9 mg/kg, 5.7 mg/kg and 3.8 mg/kg.
Cadmium (Cd) In the dry season and wet season, concentrations of cadmium in all locations were not detected (<0.1 mg/kg), or were below instrument detection limit. Therefore, cadmium values were far below the sediment criteria according to ANZECC-ISQG of 1.5 mg/kg (lower limit).
Chromium (Cr) In the dry season, concentrations of Cr ranged between 13 – 31 mg/kg. Location OS- 14, approximately 9 km offshore from Kalitami to the south, was the site of samples with highest Cr value of (31 mg/kg) however the Cr concentration was still far below the lower limit of sediment criteria set in ANZECC-ISQG of 80 mg/kg. The lowest Cr concentration of 13 mg/kg was detected in two sampling locations, namely OS-06 and OS-09.
In the wet season, Cr concentrations ranged between values 9.2 – 26.2 mg/kg. Location of OS-07, approximately 10 km west of the Combo Dock, was the sampling location with highest Cr value (26.2 mg/kg) however this value was still far below the lower limit of sediment criteria set in ANZECC-ISQG of 80 mg/kg.
Copper (Cu) In the dry season, concentrations of Cu ranged between 1.5 – 13.4 mg/kg. Location of OS-14 approximately 9 km offshore from Kalitami to the south was the sampling location with highest value of Cu (13.4 mg/kg). However the Cu concentration was still far below the lower limit of sediment criteria set in ANZECC-ISQG of 65 mg/kg. The lowest Cu concentration of 1.5 mg/kg was detected at sampling location OS-06.
In the wet season, concentrations of nickel ranged between 0.2 – 8.11 mg/kg. OS-11 was the sampling location with highest value (8.11 mg/kg) however the value was still far below the lower limit of sediment criteria determined in ANZECC-ISQG of 65 mg/kg.
Mercury (Hg) In the dry season, concentration of Hg ranged between 0.004 – 0.054 mg/kg. Sampling location OS-11 positioned approximately 3 km northwest of the VRA offshore platform, had the highest concentration of Hg at 0.054 mg/kg however the value was far below the lower limit set by ANZECC-ISQG of 0.15 mg/kg.
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In the wet season, Hg concentrations ranged between 0.005 – 0.032 mg/kg. Similar to the dry season, sampling location OS-11 in the wet season also had the highest Hg concentration of 0.032 mg/kg, however the value was still far lower than the lower limit set by ANZECC-ISQG of 0.15 mg/kg.
Silver (Ag) In the dry season and wet season silver content in all sampling locations were not detected (<0.4 mg/kg). This indicated that in all sampling locations, Ag content was still far below the lower limit set by ANZECC-ISQG of 1 mg/kg.
Lead (Pb) In the dry season, Pb concentration ranged between 11 – 24.5 mg/kg. Sampling location OS-06, approximately 6 km offshore from Onar Baru to the west, had the highest Pb concentration of 24.5 mg/kg however the value of Pb was still far below the ANZECC-ISQG lower limit of 50 mg/kg. Two Pb sampling locations, namely OS-03 and OS-09 had the lowest concentration of 11 mg/kg.
In the wet season, the Pb concentration ranged between 6.0 – 28 mg/kg. Sampling location OS-07 in position of some 10 km to the west of the Combo Dock was the sampling location with the highest value (28 mg/kg) however the value was still far below the lower limit of sediment criteria set in ANZECC-ISQG of 50 mg/kg. The lowest Pb concentration was detected at location OS-03.
Nickel (Ni) In the dry season, nickel concentration ranged between 16.3 – 32.4 mg/kg. The highest values of 32.4 mg/kg was detected at location OS-14 approximately 9 km offshore from Kalitami to the south and 27.3 mg/kg at location OS-11 at position of some 3 km to the northwest of offshore platform VRA. At location OS-8, nickel concentration value was 21.9 mg/kg and at location OS-10 the value was 21.4 mg/kg followed by 21.2 mg/kg at location OS-01.
Nickel concentration in the five locations of OS-14, OS-11, OS-08, OS-10, and OS-01 exceeded the lowest limit of ANZECC-ISQG sediment criteria of 21 mg/kg, while four other locations namely OS-09, OS-12, OS-03 and OS-07 with nickel concentrations of respectively 20.9 mg/kg, 20.2 mg/kg, 19.6 mg/kg and 19.1 mg/kg approached the lower limit value of ANZECC-ISQG sediment criteria of 21 mg/kg, but were still below the upper limit of sediment criteria set by ANZECC-ISQG of 52 mg/kg. In other locations , namely OS-04 and OS-06, nickel concentration values were 17.05 mg/kg and 16.3 mg/kg.
In the wet season, concentrations of nickel ranged between 10.3 – 25.01 mg/kg. A total of four out of 14 sampling locations had nickel concentrations exceeding the lower limit value for sediment criteria set by ANZECC-ISQG of 21 mg/kg. The four locations are OS-08, OS-10, OS-11 and OS-07 with nickel concentration of respectively 25.01 mg/kg, 24.7 mg/kg, 23.7 mg/kg and 22.8 mg/kg.
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Similarly, four locations OS-13, OS-06, OS-09 and OS-03 had nickel concentration approaching the lower limit value of sediment criteria set by ANZECC-ISQG of 21 mg/kg. The four locations respectively had nickel concentrations of 19.7 mg/kg, 19.4 mg/kg, 19.2 mg/kg and 18.8 mg/kg.
While five other locations namely OS-12, OS-5, OS-04, OS-14 and OS-02 had nickel concentration values of respectively 16.6 mg/kg, 15.01 mg/kg, 14.6 mg/kg, 11.7 mg/kg and 10.3 mg/kg.
Selenium (Se) In the dry season, concentration of selenium ranged between 0.01 – 1.1 mg/kg. The highest selenium value of 1.1 mg/kg detected in location OS-03 (some 21 km southeast of Arguni), exceeded the lower limit of 1 mg/kg, however was still below the upper limit of 4 mg/kg based on sediment criteria of Van Derveer and Canton (1997). In five out of ten locations , namely OS-04, OS-06, OS-08, OS-11 and OS-12 selenium concentrations indicated values <0.01 mg/kg or below the instrument detection limit.
In the wet season, selenium concentrations ranged between 0.01 – 0.33 mg/kg. Highest selenium value of 0.33 mg/kg was detected at location OS-13 (approximately 21 km east of the VRB offshore platform), however the value was still below the lower limit of sediment criteria from Van Derveer and Canton (1997) of 1 mg/kg. A total of three out of the 14 sampling locations had selenium concentrations <0.01 mg/kg, i.e. at locations OS-02, OS-09 and OS-12.
Zinc (Zn) In the dry season, zinc concentrations ranged between 35.3 – 70.1 mg/kg. The highest value of 70.1 mg/kg was detected in location OS-14 (some 9 km offshore from Kalitami to the south) and the lowest value of 35.33 mg/kg at location OS-04. Zinc concentrations were still far below the lower limit of ANZECC-ISQG sediment criteria of 200 mg/kg.
In the wet season, zinc concentrations ranged between 26.79 – 67.25 mg/kg. The highest value of zinc of 67.25 mg/kg was detected at location OS-07 at position of approximately 10 km to the west of the Combo Dock and the lowest value of 26.79 mg/kg was found at location OS-02. The value of zinc concentration was still far below the lower limit of ANZECC-ISQG sediment criteria, i.e 200 mg/kg.
Total Petroleum Hydrocarbon (TPH) In the dry season and wet season TPH in all locations was not detected (<2 mg/kg), or was below the instrument detection limit, except at one location namely OS-14 (approximately 9 km offshore from Kalitami to the south) it was found with value of 19 mg/kg in the wet season . The criteria for upper limit concentration of TPH in sediment as set by ANZECC-ISQG is 0.3 mg/kg.
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2.1.9.2 Seabed Sediment of Nearshore
Antimony (Sb) In the dry season, concentrations of Sb ranged between 0.01 – 0.87 mg/kg. The highest value of Sb at 0.87 mg/kg was detected at location NS-08 (approximately 1 km offshore from Weriagar to the south) and lowest value of <0.01 mg/kg at location NS-05. All the sampling locations were still below the lower limit of the ANZECC-ISQG sediment criteria of 2 mg/kg.
In the wet season, concentrations of Sb ranged between the values 0.17 – 0.81 mg/kg. All sampling locations in the wet season were still below the lower limit of the ANZECC-ISQG sediment criteria of 2 mg/kg.
Arsenic (As) In the dry season, concentrations of arsenic were detected in the range between 7.0 – 17.65 mg/kg. The highest value of arsenic of 17.65 mg/kg was detected at location NS-06 (approximately 125 km from VRB to the east) and 17.11 mg/kg at location NS-08 (approximately 1 km offshore from Weriagar to the south). The two locations approached the ANZECC-ISQG lower limit value of 20 mg/kg. A total of seven other locations had values of samples below the ANZECC-ISQG lower limit of 20 mg/kg. In the wet season, concentrations of arsenic were detected in the range between 4.5 – 60.0 mg/kg, the lowest was detected at NS-01 and the highest at NS- 03. Concentrations of arsenic at NS-03 (in the Combo Dock area) already approached the upper limit value of ANZECC-ISQG at 70 mg/kg. The remaining arsenic concentrations in the wet season were lower than the lower limit of ANZECC- ISQG at 20 mg/kg.
Cadmium (Cd) In the dry season and wet season concentrations of cadmium were not detected (<0.1 mg/kg) or were below the instrument detection limit. Therefore, the cadmium value was far below the sediment criteria determined in the ANZECC-ISQG of 1.5 mg/kg ( lower limit).
Chromium (Cr) In the dry season, concentrations of Cr ranged between 8 – 34 mg/kg. The highest Cr value of 34 mg/kg was detected at location NS-07 (approximately 7 km northeast of VRA) and the lowest value was 8 mg/kg at location NS-01. All sampling locations indicated values that were below the lower limit of ANZECC-ISQG sediment criteria of 80 mg/kg.
In the wet season, concentrations of Cr ranged between 14 – 37 mg/kg. All sampling locations in the wet season indicated values that were below the lower limit of the ANZECC-ISQG sediment criteria at 80 mg/kg.
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Copper (Cu) In the dry season concentrations of Cu ranged between 1.24– 26.15 mg/kg. The highest Cu value of 26.15 mg/kg was detected at location NS-08 (approximately 1 km offshore from Weriagar) and the lowest value was 1.24 mg/kg at location NS-01. All the sampling locations had values of samples that were still below the lower limit of ANZECC-ISQG sediment criteria of 65 mg/kg.
In the wet season, the concentrations of Cu ranged between 3.9 – 19.7 mg/kg. The highest Cu value of 19.7 mg/kg was detected at location NS-09 (approximately 2 km offshore from Kalitami) and the lowest value was 3.9 mg/kg at location NS-02. All the sampling locations in the wet season indicated values that were still below the ANZECC-ISQG sediment criteria of 65 mg/kg.
Mercury (Hg) In the dry season, Hg concentration ranged between 0.007 – 0.077 mg/kg. Sampling location NS-08 (approximately 1 km offshore from Weriagar) had the highest Hg concentration of 0.077 mg/kg, this value far exceeded the lower limit value set by ANZECC-ISQG of 0.15 mg/kg and approached the upper limit value of ANZECC- ISQG at 1 mg/kg.
In the wet season Hg concentration ranged between 0.01 – 0.05 mg/kg, therefore the value of Hg concentration was far below the lower limit set by ANZECC-ISQG of 0.15 mg/kg.
Silver (Ag) In the dry season and wet season, silver content in all sampling locations were not detected (<0.4 mg/kg), or were below the instrument detection limit. This indicated that in all sampling locations, Ag values were still far below the lower limit set by ANZECC-ISQG of 1 mg/kg.
Lead (Pb) In the dry season, Pb concentrations ranged between 6 – 18 mg/kg. Sampling location NS-08 (approximately 1 km offshore from Weriagar) had the highest Pb concentration of 18 mg/kg however this value was still far below the lower limit set by ANZECC-ISQG of 50 mg/kg. Sampling location NS-07 had the lowest concentration of Pb at 6 mg/kg.
In the wet season, Pb concentration ranged between 6 – 15 mg/kg. Sampling location NS-09 (approximately 2 km offshore from Kalitami) had the highest Pb concentration of 15 mg/kg however the Pb concentration value was still far below the lower limit according to ANZECC-ISQG of 50 mg/kg. Similar to sampling during the dry season, in the wet season the lowest concentration of Pb was detected at sampling location NS-07.
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Nickel (Ni) In the dry season, nickel concentration ranged between 3.8 – 46.4 mg/kg. The highest value of 46.4 mg/kg was detected at location NS-07 (approximately 2 km offshore from Sorondauni), at location NS-06 (approximately 125 km from VRB to the east) was detected at 34.6 mg/kg and at location NS-02 (approximately 52 km to the east of Arguni) in the amount ot 28.9 mg/kg. Further, in location NS-09 at 27.2 mg/kg, location NS-04 at 25.03 mg/kg and followed by 23.4 mg/kg in location NS- 08.
Nickel concentration in the six locations of NS-07, NS-06, NS-02, NS-09, NS-04 and NS-08 have exceeded the lower limit value of sediment criteria set by ANZECC- ISQG of 21 mg/kg, while two other locations, i.e. NS-05 and NS-03 with nickel concentration of respectively 18.23 mg/kg and 18.21 mg/kg approaching the lower limit of criteria sediment ANZECC-ISQG namely 21 mg/kg. Location NS-01 had the lowest concentration of nickel at 3.8 mg/kg.
In the wet season, nickel concentration ranged between 12.5 – 44.8 mg/kg. A total of four locations from eight sampling locations had concentration of nickel exceeding the lower limit value of sediment criteria according to ANZECC-ISQG of 21 mg/kg. The four locations are NS-07, NS-03, NS-09 and NS-04 with nickel concentration of respectively 44.8 mg/kg, 29.7 mg/kg, 27.4 mg/kg and 21.5 mg/kg.
Similarly, in two other locations of NS-05 and NS-08, nickel concentration is approaching the lower limit value of sediment criteria according to ANZECC-ISQG of 21 mg/kg. The two locations respectively had nickel concentration of 17,9 mg/kg and 16,3 mg/kg. Sampling location NS-06 and NS-02 had nickel concentration of respectively 13.2 mg/kg and 12.5 mg/kg.
Selenium (Se) In the dry season, concentrations of selenium ranged between <0.01 – 0.3 mg/kg. The highest value of selenium was 0.35 mg/kg detected at location NS-06 and followed by location NS-08 with value of 0.3 mg/kg, however the selenium concentrations were still far below the lower limit of 1 mg/kg according to the criteria of Van Derveer and Canton (1997). The lowest selenium value of <0.01 mg/kg was detected at location NS-01. The criteria of Van Derveer and Canton (1997) were referred to since the ANZECC-ISQG criteria does not include selenium.
In the wet season, concentrations of selenium ranged between <0.01 – 0.47 mg/kg. The highest value of selenium was 0.47 mg/kg was detected at location NS-04, while the lowest concentration of <0.01 mg/kg was found at location NS-08.
Zinc (Zn) In the dry season the concentration of zinc ranged between 6.2 – 89.3 mg/kg. There are two sampling locations with highest Zn concentration at locations NS-06 and NS-08 with values of respectively 89.3 mg/kg and 81.3 mg/kg, however the values are still far below the lower limit set by ANZECC-ISQG at 200 mg/kg.
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In the wet season, zinc concentrations ranged between 34.1 – 87.2 mg/kg. Two sampling locations with highest Zn concentration were locations NS-09 and NS-07, with values of 87.2 mg/kg and 84.3 mg/kg, however these values were still far below the lower limit of ANZECC-ISQG at 200 mg/kg.
Total Petroleum Hydrocarbon (TPH) In the wet season, TPH in all locations were not detected (< 2 mg/kg) or below the instrument detection limit. While in the dry season TPH was detected in sampling locations NS-01, NS-04, NS-06 and NS-08 with concentrations of respectively 13 mg/kg, 10 mg/kg, 22 mg/kg and 18 mg/kg. Upper limit criteria for TPH concentrations in sediment as set in ANZECC-ISQG was 0.3 mg/kg.
2.1.9.3 Riverbed Sediment
In general, concentration of heavy metal in river sediments met the Criteria of Sediment Quality based on ANZECC-ISQG, or below the lower limit, however nickel and arsenic content both in the dry season as well as wet season had tendency to exceed the lower limit of sediment criteria set by ANZECC-ISQG, similar to nearshore and offshore seabed sediment.
Nickel (Ni) Concentrations of nickel in SW-01 and SW-03 in the dry season and wet season ranged between 5.7 – 36.3 mg/kg. In the dry season and wet season, the concentration of nickel for location SW-01 exceeded the lower limit of sediment quality criteria based on ANZECC-ISQG (21 mg/kg dry) namely 34.7 mg/kg in the dry season and 30.7 mg/kg in the wet season. Similarly, in the wet season at location SW-03, nickel concentrations in river sediment were detected at 36.3 mg/kg or exceeding the lower limit of sediment quality criteria based on ANZECC-ISQG.
Arsenic (As) Concentrations of arsenic at SW-01 and SW-03 in the dry season and wet season ranged between 5.1 – 21.5 mg/kg. In the dry season, arsenic concentrations in location SW-01 exceeded lower limit criteria of sediment quality based on ANZECC-ISQG (20 mg/kg), i.e. 21.5 mg/kg. Moreover, sediment concentration was still below the lower limit.
Cadmium (Cd) Concentrations of cadmium in river sediment in two locations namely SW-01 and SW-03 in the dry season and wet season were not detected or below the instrument detection limit of <0.1 mg/kg. Lower limit criteria of sediment quality based on ANZECC-ISQG was 1.5 mg/kg.
Chromium (Cr) Concentrations of chromium in two locations namely SW-01 and SW-03 in the dry season and wet season were in the range between 4 - 31 mg/kg or below the lower limit of sediment quality criteria based on ANZECC-ISQG of 80 mg/kg.
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Copper (Cu) Copper concentrations in river sediment at locations SW-01 and SW-03 in the dry season and wet season had a range of 0.9 – 12.4 mg/kg or below the lower limit of sediment quality criteria based on ANZECC-ISQG of 65 mg/kg.
Lead (Pb) Concentrations of lead in two locations SW-01 and SW-03 in the dry season and wet season were in the range of 2 – 17 mg/kg or below the lower limit of sediment quality criteria based on ANZECC-ISQG of 50 mg/kg.
Mercury (Hg) Concentration of mercury in the two locations SW-01 and SW-03 in the dry season and wet season were in the range of 0.004 – 0.035 mg/kg or below the lower limit of sediment quality criteria based on ANZECC-ISQG of 0.15 mg/kg.
Selenium (Se) Selenium concentrations in two locations at SW-01 and SW-03 both in the dry season and wet season had range between 0.04 – 0.1 mg/kg or were below lower limit concentration of selenium in sediment based on Van Derveer and Canton (1997) i.e. 1 mg/kg. The criteria of Van Derveer and Canton (1997) are referred to since the ANZECC-ISQG criteria does not include selenium.
Silver (Ag) Silver concentrations in river sediment at locations SW-01 and SW-03 in both the dry season and wet season were not detected or were below the instrument detection limit of <0.4 mg/kg. Lower limit criteria of sediment quality based on ANZECC- ISQG was 1 mg/kg.
Zinc (Zn) Concentrations of zinc in the two locations of SW-01 and SW-03 in both the dry season and wet season were in the range of between 12.5 – 91.1 mg/kg or below the lower limit of sediment quality criteria based on ANZECC-ISQG of 200 mg/kg.
Total Petroleum Hydrocarbon (TPH) TPH in riverbeds was only detected at sampling location SW-01 in the dry season at 3 mg/kg, furthermore TPH was not detected or was below the instrument detection limit (<2 mg/kg). The criteria for upper limit concentration of TPH in sediment as set by ANZECC-ISQG was 0.3 mg/kg.
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Mercury (Hg) Lead (Pb) Nickel (Ni) Zinc (Zn) Arsen (As)
Antimoni (Sb)
Figure II-91 Graph of Median Value and Range Value (Minimum) of Metal Concentration in Bed Sediment of Offshore, Onshore, and River Waters
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Based on the above explanation, generally the heavy metals concentration in sediment from the monitoring results in the dry season ( 2012) and wet season (2013) complied with the criteria of sediment quality based on ANZECC-ISQG as well as Van Derveer and Canton (1997) for parameter of selenium, or was below the lower limit, however for nickel and arsenic content, in both the dry season and wet season had tendency to exceed the lower limit of sediment criteria set by ANZECC- ISQG. The monitoring results were in line with the environmental monitoring results made before and during the Tangguh LNG operation (LNG Train 1 and 2), in which the values for concentrations of nickel and arsenic exceeded the upper limit of ANZECC-ISQG sediment criteria, with the following description:
From 1996 up to 2011, totally 166 sediment samples in the waters of Bintuni Bay around the Tangguh LNG site and in areas that were sufficiently far from the Tangguh LNG activity site were taken The analysis results showed that nickel concentrations exceeded the lower and upper limits of ANZECC-ISQG sediment criteria, encompassing the metals nickel, arsenic, cadmium and mercury. Concentrations of nickel ranged between 20.3 - 348 mg/kg. The values were based on observation of samples from 1996 up to 2011, except for 2002, 2003, 2005 and 2006 in which samples were only taken in Babo. Distribution of sediment sampling from year 1966 up to 2011 are shown in Figure II-92.
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Table II-45 Number of Samples Exceeding Sediment Criteria and Range Values (mg/kg) Number of Samples Exceeding Sediment Criteria and Range Value (mg/kg)
As Cd Cr Cu Hg Pb Ni
Year Location Range Criteria Range Criteria Range Criteria Range Criteria Range Criteria Range Criteria Range Criteria
(mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) mg/kg (mg/kg) mg/kg e exceeding mg/kg mg/kg (mg/kg) mg/kg mg/kg mg/kg le exceeding le exceeding le exceeding le exceeding le exceeding le exceeding le l 20 mg/kg 80 mg/kg 65 mg/kg 50 mg/kg 21 mg/kg 1,5 mg/kg 0,15 mg/kg 0,15 Number of Samples of Number amp Samp Samp Samp S Samp Samp Samp
1996 Weriagar 3 - 20 - 70 - - 1,5 - 10 - - 80 - 370 - - 65 - 270 - 1.32 0.15 - 1 1 - 50 - 220 - 23,65 21 - 52 3 2000 Weriagar, LNG, Vorwata 45 20 - 74 20 - 70 15 - 1.5 - 10 - - 80 - 370 - - 65 - 270 - 1.98 0.15 - 1 1 - 50 - 220 - 22,4 - 42,7 21 - 52 44 2001 LNG 15 30 - 64 20 - 70 2 1.5 - 10 - - 80 - 370 - - 65 - 270 - - 0.15 - 1 - - 50 - 220 - 20,3 - 75,9 21 - 52 15 2002 Babo 2 - 20 - 70 - - 1.5 - 10 - - 80 - 370 - - 65 - 270 - - 0.15 - 1 - - 50 - 220 - - 21 - 52 -
2003 Babo 1 20 - 70 - 1.5 - 10 - - 80 - 370 - - 65 - 270 - - 0.15 - 1 - - 50 - 220 - - 21 - 52 - 2005 Babo 2 20 - 70 - 1.5 - 10 - - 80 - 370 - - 65 - 270 - 4.69 0.15 - 1 1 - 50 - 220 - - 21 - 52 - 2006 Babo 1 - 20 - 70 - - 1.5 - 10 - - 80 - 370 - - 65 - 270 - 0.15 - 1 - - 50 - 220 - - 21 - 52 - 2007 Vorwata - Babo LNG, Roabiba 18 - 20 - 70 - - 1.5 - 10 - - 80 - 370 - - 65 - 270 - 2.08 - 2.61 0.15 - 1 7 - 50 - 220 - 21,6 - 24,4 21 - 52 3 2008 Vorwata - Babo 1.52 – 0.55 – LNG, Roabiba 25 - 20 - 70 - 1.77 1.5 - 10 4 - 80 - 370 - 65 - 270 - 0.88 0.15 - 1 2 - 50 - 220 - 21,3 - 348*) 21 - 52 4
Vorwata - Babo 31.6 - 2009 LNG, Roabiba 21 126 20 - 70 7 - 1.5 - 10 - - 80 - 370 - - 65 - 270 - - 0.15 - 1 - - 50 - 220 - 21,2 21 - 52 1 Vorwata - Babo 21.6 - 2011 LNG, Roabiba 33 162 20 - 70 17 2.1 - 3.4 1.5 - 10 7 - 80 - 370 - - 65 - 270 - - 0.15 - 1 - - 50 - 220 - 21,7 - 39,3 21 - 52 28 166 41 11 12 98
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Figure II-92 Distribution of Metal Content (As, Hg, Cd and Ni) in Marine Sediment Exceeding the ANZECC Criteria
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Arsenic content ranged between 20 – 162 mg/kg. The value was higher than the criteria for sediment specified in ANZECC-ISQG of 20 mg/kg (lower limit) – 70 mg/kg (upper limit). The value was based on sampling results of 2000, 2001, 2009 and 2011.
The high concentrations of nickel and arsenic in sediment are natural indicators for the Bintuni Bay seabed. In general, the presence of nickel is in areas with nickel laterite deposits in ultrabase igneous rock, while arsenic content is in intermediate igneous rock.
Nickel laterite deposits are products of advanced weathering process in ultramafic rock carrying Ni-Silicate. Indonesia is known worldwide as a leading producer of mine products, including nickel. Based on geological characteristic and tectonic order, several locations have potential nickel laterit deposits in Indonesia and are generally dispersed in the eastern part of Indonesia, among others: Pomalaa (Southeast Sulawesi), Sorowako (South Sulawesi), Gebe (Halmahera), Tanjung Buli (Halmahera), and Tapunopaka (Southeast Sulawesi). While several locations estimated to also possess potential nickel laterite deposits and were so far conducting exploration activities were found in small islands around Halmahera Island, among others Obi Island, Gee island, and Pakal Island.
In the West Papua area, nickel deposits are found in Waigeo Path encompassing the Bird’s Head area including Gag Island located approximately 160 km from Sorong to the west (Mines and Energy Service of Jayapura, 2004). Figure II-93 shows the distribution of ultabasic sediment starting from Sulawesi, North Maluku, Gag Island to Papua.
Tangguh LNG activities are not connected to the presence of nickel and arsenic in the waters of Bintuni Bay. In the industrial process, it is common that gold ore processing or pesticide industry will produce waste containing arsenic. Apart from that, in nature arsenic content in shale and clay rock ranges between 0.3 – 490 mg/kg and in ultrabasic rock ranges between 0.3 – 16 mg/kg (National Academy of Science, 1977).
Apart from nickel and arsenic, results of monitoring in 1996 up to 2011 also indicated that mercury and cadmium in several sampling locations exceeded the lower limit and upper limit criteria of ANZECC-ISQG. Mercury content in sediment recorded 10 data with indication of exceeding the ANZECC-ISQG upper limit criteria of 1 mg/kg, and two data points exceeded the ANZECC-ISQG lower limit criteria of 0.15 mg/kg. As for cadmium content, of 58 data points a total of 11 data indicated values exceeding lower limit criteria ANZECC-ISQG of 1.5 mg/kg.
Comparison with various environmental baseline data starting from 1996 gave indication of the existence in nature of several metal parameters of high concentration in Bintuni Bay.
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Figure II-93 Distribution of Ultramafic Rock in Sulawesi-North Maluku – Gag Island-Papua
2.1.10 Oceanography
The morphology of the Berau Bay and Bintuni Bay extends from the east to the west direction along ± 160 km with an open bay mouth in the western part that is directly connected to the waters of the Halmahera sea. The widest part of the Bintuni Bay waters reaches 50 km which is located near the bay mouth. Many rivers also empty into the bay so that the bay water salinity is lower than the sea waters in front of it.
2.1.10.1 Bathymetry
The water depth of Bintuni Bay varies from only a few meters (<5 m) along the shoreline (nearshore), up to more than 50 m in the center and near the bay mouth (Map II-14 offshore). During seawater quality sampling, the measurement indicated that particular locations were even recorded of more than 100 m.
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Map II-15 Bathymetry of the Bintuni Bay
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2.1.10.2 Waves
The wave height conditions in the Bintuni Bay waters vary from <0.4 m up to >1.6 m. The wave’s height surrounding the bay mouth are larger than at the inner bay as the areas around the bay mouth are more open, while the central part of the bay is more protected.
Wave data recording use the Interocean S4ADW current and wave meter equipment. This equipment records the wave height and direction. The EHI data (Evans-Hamilton International) by using the S4A equipment is installed at the western location of the LNG 1 jetty. Results of the wave data analysis is collected by PT. Calmarine during the period of March 1st up to June 30th, 2001 that is installed at the Ocean Tower location as illustrated in Figure II-94 and Figure II-95.
Figure II-94 Scatter Plot of the Significant Wave Height vs the Average Wave Direction in the Period of March 1st up to June 30th, 2001
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100
90
80
70
60
50
40 % Exceedance
30
20
10
0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Significant Wave Height (m) 90
80
70
60
50
40 % Occurrence 30
20
10
0 0 < 0.2 0.2 < 0.4 0.4 < 0.6 0.6 < 0.8 0.8 < 1.0 1.0 < 1.2 Significant Wave Height (m) 50
45
40
35
30
25
20 % Occurrence 15
10
5
0 3.0 < 3.5 3.5 < 4.0 4.0 < 4.5 4.5 < 5.0 5.0 < 5.5 5.5 < 6.0 Zero Crossing Wave Period (secs)
Figure II-95 Percentage (%) of Height Occurrences (Hs) and Zero Crossing Wave (Tz) in the Period of March 1st up to June 30th, 2001
Based on data from EHI and Calmarine in AMDAL (2002), the frequency of wave occurrences between 0 to 0.4 m are approximately 90%. This means that approximately 90% of waves heights in the bay are less than 0.4 m (40 cm) and only 1.2% wave occurrences having a significant height of more than 1.0 m.
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Table II-46 Significant Wave Height and Occurrence Frequencies in the Bintuni Bay Waters Occurrence Frequency (%) Significant Wave Height (m) Data from EHI Data from Calmarine 0 up to 0.4 95.2 91.4 0.4 up to 0.8 4.1 7.4 0.8 up to 1.2 0.7 1.2 1.2 up to 1.6 0.06 0.1 >1.6 0.02 None Source: EHI and Calmarine in Amdal, 2002
LAPI ITB (2013) used MuSed3D software to estimate the hydrodynamic condition in the sea around the Combo Dock. Hindcast of waves was conducted by using the NOAA wind data at 131.75o E, 02.50o S as wind data every 6-hours from 1999 to 2011. Wave estimates were performed in the waters surrounding the Combo Dock wherein the effect of the wave transformations can be ignored. This model was validated with data from an oceanography survey by Calmarine (1999) with good results.
Estimates of significant height and wave period are presented in Table II-47. Estimates of extreme wave heights for each return period are presented in Table II-48. Percentage of wave occurrences at the Combo Dock location is approximately 71%, or 21% of the sea in calm conditions.
Table II-47 The Height (Hs) and Period (Ts) of Significant Waves Hs (m) Ts (s) Significant 0.58 2.73 Max 2.88 6.16 Average 0.35 2.10 Min 0.01 0.36 Source: LAPI ITB (2013)
Table II-48 Estimates of Extreme Wave Heights Repeated Period (Year) Extreme Wave Heights (m) 1 1.44 2 1.63 3 1.82 5 2.03 10 2.29 25 2.61 50 2.85 100 3.08 200 3.31 Source: LAPI ITB (2013)
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2.1.10.3 Tidal
Based on measurement results of sea levels performed at Tanah Merah in the period of October 21st, 1999 to March 3rd, 2000 by Calmarine, tidal constituents were obtained as presented in Table II-49. By using the tidal constituents, the Formzhal value of 0.36 can be obtained. This figure means that the tidal type at the location is mixed tide prevailing semi-diurnal.
Table II-49 Tidal Constituents at Tanah Merah, Bintuni Bay Waters (AMDAL, 2002) Tidal Constituent M2 S2 N2 K2 K1 O1 P1 M4 MS4 Z0 F Amplitude Constituent, H 0.89 0.27 0.20 - 0.45 0.27 0 0.03 0.02 2.15 0.62 (m) Constituent Phase, g (˚) 179 272 125 - 347 313 348 322 058 - - Source: Analysis Data of MetOcean, Calmarine, 2002
Fluctuations of seawater surfaces at Combo Dock at a depth of +6 m LAT at the period December 24th, 2012 up to April 12th, 2013 (Fugro Geos PTE Ltd, 2013) is presented in Figure II-96. The maximum water height during observations recorded by devices installed at a depth of 0.5 m above average seawater level is 1.7 m that was recorded on March 31st, 2013 at 00:00 WITA. The minimum height is -2.2 m which was recorded on January 12th, 2013, at 03:10 pm WITA.
Figure II-96 Fluctuations of Seawater Level at the Ocean Tower Location in Bintuni Bay Waters
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Map II-16 Ocean Tower Location
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2.1.10.4 Current
Current measurement results using the mooring method at the center of narrowest bay in front of Tanah Merah showed that current movements were dominated by the Northeast and Southwest directions (Figure II-97). At the scatter plot figure, Figure II-97 (left), it can be observed that the current spread forms an ellipse in the northeast and southwest directions. The condition indicated that the current movement direction is alternating in the northeast and northwest direction or indicated that the current movement was dominated by tidal.
Figure II-97 (right) shows the direction and velocity of the current. The maximum velocity on the major axis at the depth of 5.5 m above the seabed can reach 74.4 cm/sec, while on the minor axis is 5.0 cm/sec. At the layer of 0.5 m from the sea bed are respectively 46.0 cm/sec on the major axis and 6.1 cm/sec on the minor axis.
Figure II-97 Scatter Plot and Current Rose at the Ocean Tower Location in the Period of December 7th, 1999 up to March 3rd, 2000. A- Position of current meter is at 5.5 m above the sea bed and the B- Position of current meter is at 0.5 m above the sea bed
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December 7th, 1999 up to March 3rd, 2000 March 1st up to Mei 31st, 2000
June 1st up to Augusts 30th, 2000 September 1st up to December 4th, 2000
December 1st up to February 28th, 2001 March 1st up to June 30th, 2001 Figure II-98 Scatter Plots of Each Quarter at the Period of December 7th, 1999 up to June 30th, 2001
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Based on Figure II-98, it can be observed that the pattern of quarterly current direction during 18 months of measurement (December 7th, 1999 up to June 30th, 2001) has similar current direction pattern that is similar to the average current direction towards 45˚ up to 87.5˚ and 225˚ up to 247.5˚. This condition explains that the current in the Bintuni Bay is very strongly affected by the tidal because of the alternating current movement direction in the northeast and northwest direction, although in different monsoons.
Current Simulation Instantaneously current measurements in the field are not sufficient to observe the current pattern figure in the bay, but the data can be used to validate the current simulation model. A combination of the directly current measurement in the field and the simulation results can provide an understanding of the current pattern occurring in the bay spatially and temporarily.
To observe the current pattern spatially and temporarily based on the different monsoons, therefore a simulation current was performed. The input of model used in the simulation is the bathymetry, tidal (Figure II-99), and wind data (Figure II-100).
Figure II-99 Tidal Data Used in the Current Simulation, January Represents the Northeast Monsoon and August Represents the Southeast Monsoon
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Figure II-100 Wind Data Used in the Current Simulation, January Represents the Northeast Monsoon and August Represents the Southeast Monsoon
Seawater level fluctuations for 15 days were plotted in a graphical form of the time- based seawater level elevation (Figure II-99), either that represents the northeast monsoon in January (upper panel) and that represents the southeast monsoon (lower panel). In general, it can be observed that the maximum tidal range within 15 days almost reaches 2 m, in particular during the spring tide.
Wind data used as input data in the simulation is the average wind data in January and October during the last ten years. In the northeast monsoon which is represented by the average wind in January during ten years, the dominant wind blows from the northwest direction with a wind velocity of > 5.5 m/sec (Figure II-100 – left hand side).
In the southeast monsoon (June-August) or known as the Southeast Monsoon, the wind dominantly blows from the southeast and from the south with a velocity of 8-9 m/sec (Figure II-100 – right hand side).
Current simulation results in two different monsoons are shown in Figure II-101 up to Figure II-104 for the northeast monsoon, and Figure II-105 up to Figure II-108 for the southeast monsoon. In each monsoon, four figures of current patterns are shown which it respectively represents the seawater level position during the seawater level at MSL (Mean Sea Level) moves to the highest tide point, when the water level is at the highest tide, when the seawater level at the MSL moves to the lowest ebb point and when the water level is at the lowest ebb point. A. Results of Current Simulation Model in the Northeast Monsoon Based on Figure II-101, the current moves into the Bintuni Bay when the water level is at the MSL heading to the highest tide point, however it is not the case with the current condition in the eastern end of the bay, which there are estuaries so that the current can be observed to move in the opposite direction i.e. towards the bay mouth. The current velocity is observed to vary between 5
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cm/second to approaching 100 cm/second near the mouth, in particular the inner part of the bay.
Figure II-101 Current Pattern as Simulation Result When the Seawater Level at the MSL Point Moves Towards the Highest Tide Point in January Representing the Northeast Monsoon at the Bintuni Bay
When the water level is at the highest tide point, the water movement pattern or current pattern in the bay is illustrated in Figure II-102. Significant changes occur in the surroundings of the bay head, the current pattern occurring is observed entering the river mouths due to during the highest tide, water masses pushing from the sea direction is extremely maximum. The current velocity at the highest tide in the deep bay are still visible to be faster of approximately 5 cm/second, while in the surroundings of the bay mouth the current velocity can reach 100 cm/second.
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Figure II-102 Current Pattern as Simulation Results When the Seawater Level is at the Highest Tide Point in January Representing the Northeast Monsoon at Bintuni Bay
The next phase after the water level position is at the highest tide point is when the water level is at the MSL moving to the lowest ebb point. The current pattern when the water level at the MSL moves towards the lowest ebb point is illustrated in Figure II-103. Almost in the entire bay water mass movements are to the outside through the bay mouth. Only in a few parts it can still be observed that water mass moves to river. The current velocity when the water level position is at the MSL point heading to the ebb ranges from 5 cm/second up to nearly 100 cm/second. Similar to the previous seawater level position, current velocity is faster as observed at deeper bay (marked in dark blue colour).
Considering that the type of tide occurring in the Bintuni Bay is a mixed tide prevailing semi-diurnal, therefore after 6 hours of the tide, ebb occurs. At the time the water level is at the lowest ebb point, the occurring current pattern is illustrated at Figure II-104. In all the parts of the bay and river estuaries masses of water move out through the bay mouth. At the inner part, the velocity current is observed to be strong >100 cm/second, while near the shoreline it is much slower (<10 cm/second).
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Figure II-103 Current Pattern of Simulation Results when the Seawater Level at the MSL Point Moves Towards the Lowest Ebb Point in January Representing the Northeast Monsoon at Bintuni Bay
Figure II-104 Current Pattern of Simulation Results when the Seawater Level at the Lowest Ebb Point in January Representing the Northeast Monsoon at Bintuni Bay
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B. Results of the Current Simulation Model in the Southeast Monsoon Illustrations of current patterns occurring in the southeast monsoon can be identified by using a current simulation in August which is the peak of the southeast monsoon. Wind data used in the current simulation in the east monsoon is the average wind data for the last decade. Figure II-105 up to Figure II-108 are current pattern models when the water level position is at four different positions, namely when the seawater level at MSL moves towards the highest tide point, when the water level is at the highest tide point, when the seawater level at MSL moves towards the lowest ebb and when the water level is at the lowest ebb position.
The current pattern is nearly similar to when the current pattern is at the same position with the current pattern occurring in the northeast monsoon as illustrated in Figure II-101 up to Figure II-104.
Figure II-105 Current Pattern of Simulation Results when the Seawater Level is at the MSL Point Moves Towards the Highest Tide Point in August Representing the Southeast Monsoon at Bintuni Bay
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Figure II-106 Current Pattern of Simulation Results when the Seawater Level is at the Highest Tide Point in August Representing the Southeast Monsoon at Bintuni Bay
Figure II-107 Current Pattern of Simulation Results When the Seawater Level at the MSL Point Moves Towards the Lowest Ebb Point in the Representing the Southeast Monsoon at Bintuni Bay
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Figure II-108 Current Pattern of Simulation Results of the Seawater Level at the Lowest Ebb Point in August Representing the Southeast Monsoon at Bintuni Bay
C. Model Verification The current model verification wass performed to identify the model conformity with the field conditions. Verification results between the model result data and measurement result data in the field are illustrated in Figure II-109. The Figure illustrates that the blue color is the measurement’s current, while the red color is the model’s current. Based on the verification it can be observed that the model’s current and the measurement’s current have similarities in terms of range and shape (ellipse).
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Figure II-109 Verification Results of the Measurement Results Current Data (in Blue) and the Simulation Model (in Red)
2.1.10.5 Profile of Temperature, Salinity and Density
Measurements of the water temperature, salinity and density were performed at 30 sampling points at the Bintuni Bay by using CTD (Conductivity-Temperature- Depth) sensors, in the northeast monsoon and the southeast monsoon (Figure II-110). The CTD instrument used can simultaneously record the profiles of temperature, seawater conductivity and pressure (which is automatically converted into depth) of the surface up to the seabed. Data recording settings of the instruments, data control and acquisition used PC-based programs so that data can be recorded with depth intervals of 1 meter starting at the surface up to near the seabed.
Measurement results of the temperature and sea water salinity was further presented in the form of vertical profiles, cross sections and horizontal distributions of temperature, salinity and density of the seawater.
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Figure II-110 Profile Measurement Location of Water Temperature, Salinity and Density at Bintuni Bay
A. Northeast Monsoon The horizontal profile of temperature in the northeast monsoon plotted from all CTD data is illustrated in Figure II-111. The differences of color and symbol on the Map indicated the different locations of the CTD stations. Seawater surface temperature ranged between 29.5 ˚C up to 31.8 ˚C. At layers deeper than >50 m, the seawater temperature ranged between 29.7 ˚C up to 30.1 ˚C. No drastic temperature decrease against the depth was observed or no thermocline layers were found.
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Figure II-111 Temperature Profile (˚C) against the Depth Plotted from All CTD Data Measured During the Northeast Monsoon (Colors Indicate CTD Stations)
Unlike the temperature profile, the salinity profile against depth in Figure II-112 indicates salinity value at the surface layers is lower than at the deeper layers. The range of seawater salinity at the surface layer is 19.0 psu (equivalent to o/oo) and 28 psu. Seawater salinity lower than 20 psu was measured in the surroundings of the river estuary. Seawater salinity value increased along with the addition of depth. At water depths of >50 m, seawater salinity can reach 33 psu. In general it can be stated that water masses with a salinity of 33 psu are seawater salinity without any mixture of fresh water masses carried by rivers.
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Figure II-112 Salinity Profile (psu) against Depth Plotted from All CTD Data Measured in the Northeast Monsoon (Colors Indicate CTD Stations)
Density is a derivative parameter that can be calculated from the data of salinity, temperature and pressure (in this case it is the depth). Seawater density data can illustrate the seawater physical condition, in particular on the stratification or water mass mixing in the waters. Figure II-113 is plotted data of salinity and temperature of each station that has been converted into density. Based on the figure, it can be observed that the seawater density in the Bintuni Bay waters is more dominantly affected by salinity. This can be indicated from the vertical profile of density that more resembles the salinity profile compared to the temperature profile.
The smallest density value was measured in river estuary area i.e. 1,010 kg/m3 with a salinity value of 19 psu and seawater temperature of 31.8 ˚C. At the depth of >50 m the seawater density can reach 1,019 kg/m3.
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Figure II-113 Density Profile (kg/m3) against the Depth Plotted from All CTD Data Measured During the Northeast Monsoon (Color Indicate CTD Stations)
Figure II-114 indicates seawater surface temperature distribusion plotted from all temperature data measured during the northeast monsoon. On the right side of the figure, there is a color scale in the form of bars, low temperature value is in purple (at the lower parts) and the highest sea water temperature is in red (upper part). The results of seawater temperature measurement indicate that the surface temperature at the bay head and in the surroundings of the river estuaries was higher (>31.5 ˚C) than the center parts and mouth of the bay (<31 ˚C).
Figure II-115 indicates that the surface salinity distribution pattern is opposite the horizontal distribution of the surface temperature, which a low salinity value (<22 psu) is observed at the head of bay and surface salinity is observed to gradually increase from the center part (23-24 psu) while at the mouth of bay the salinity increases to reach >28 psu.
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Figure II-114 Seawater Surface Temperature Distribution During the Northeast Monsoon from CTD Measurement Results
Figure II-115 Seawater Surface Salinity Distribution During the Northeast Monsoon from CTD Measurement Results
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Figure II-116 Seawater Surface Density Distribution During the Northeast Monsoon as Calculation Results from Temperature and Salinity Data Measured by CTD Sensors
Seawater surface density calculated from data of temperature, salinity and pressure is illustrated in Figure II-116. The density in the Bintuni Bay waters is strongly controlled by the salinity, this can be clearly observed as the horizontal distribution pattern of seawater density is similar to the horizontal distribution of salinity. The lighter seawater mass (indicated by the lower salinity value <1,010 kg/m3) is observed to be spread out at the bay’s head, then gradually a density value increase. In the central part, the density value reaches 1,015-1,016 kg/m3 while the highest occurs at the bay’s mouth, i.e. >1,018 kg/m3.
Cross-sections of the seawater temperature, salinity and density of the bay’s mouth to the bay’s head are also illustrated (Figure II-117 up to Figure II-125). The y-axis of each figure indicates the water depth (m), the x-axis indicates the distance (km), while the color scale on the right hand side indicates the values of deawater temperature, salinity and density. The small figure at the lower right hand side is a location Map of the CTD temperature and salinity measurement, while the red line is a transect selected to illustrate cross-sections of the seawater temperature, salinity and density.
Cross-section distribution of seawater temperature from the bay’s mouth to the head in the northeast monsoon is presented in Figure II-117. Higher water temperatures were measured at layers near the surface in the bay’s head area. The thickness of water mass layers with higher temperatures (>31.5 ˚C) were measured to a depth of 2 m, them the sea water temperature reached 30 ˚C at a depth of 5 m. At the bay’s mouth, the seawater temperature at the surface is almost similar to the temperature value at deeper depth.
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Figure II-117 Cross Section of Temperature (˚C) from the Bay’s Mouth Direction to the Bay’s Head During the Northeast Monsoon
Unlike the cross-sections of temperatures, in the cross-section of salinity clearly indicates its salinity value gradient. Water masses with low salinities (LSW = Low Salinity Water) were identified to fill the end of the bay head (20 psu). The more to the outer sides, the salinity was observed to increase (gradient colors of purple, blue and green with a salinity range of 22.5 psu up to 25 psu) as more seawater mass volumes were mixed with water masses flowing from rivers through the river mouths. Movements of water masses from the rivers after mixed with bay water that still have a lower salinity (27.5 to 28 psu) are on the seawater mass layers with a higher salinity (>30 psu).
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Figure II-118 Cross-Section of Salinity (psu) from the Bay Mouth Direction to the Head during the Northeast Monsoon
An interesting matter is observed from the cross-sections of seawater salinity and density (Figure II-119 and Figure II-122) that have similar distribution patterns. It has been mentioned that the water density in the Bintuni Bay waters are more affected by salinity. The water density value at river mouths at the bay head are lighter (<1,012 kg/m3) than at the central part and the bay mouth (>1,018 kg/m3). In other words, the lighter water mass is at the upper layer (fresh water mass from the rivers that are mixed with bay water), while the heavier water masses are in the lower layers, because it is heavier. Most of the water mass volume located near the seabed originates from the sea.
Figure II-119 Cross-Section of Density (kg/m3) from the Bay Mouth to the Head Direction During the Northeast Monsoon
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Figure II-120 Cross-Section of Temperature (˚C) from the North Side to the South Side Near the Bay Mouth During the Northeast Monsoon
Figure II-121 Cross-Section of Salinity (psu) from the North Side to the South Side Near the Bay Mouth During the Northeast Monsoon
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Figure II-122 Cross-Section of Density (kg/m3) from the North Side to the South Side Near the Bay Mouth During the Northeast Monsoon
Figure II-123 Cross-Section of Temperature (˚C) from the North Side to the South Side in the Bay Central Part During the Northeast Monsoon
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Figure II-124 Cross-Section of Salinity (psu) from the North Side to the South Side in the Bay Central Part During the Northeast Monsoon
Figure II-125 Cross-Section of Density (Kg/m3) from the Bay South Side to the Central Part During the Northeast Monsoon
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B. Southeast Monsoon The southeast monsoon is a certain period (June to August) in a year which the dominant wind blows from the southeast direction (from the Australian direction) heading northwest and when passing the equator the wind direction turns towards the Pacific Ocean. During the southeast monsoon, at the Arafura Sea and Banda Sea water masses rise from the bottom layers to the upper layers (upwelling). Similar to the northeast monsoon, measurement of temperature and salinity parameter was also performed at the same location by using CTD (Conductivity-Temperature- Depth) sensors. Data analysis results, profile figures and cross-sections of temperature, salinity and density of the bay water during the southeast monsoon are presented in Figure II-126 up to Figure II-131.
Temperature profiles plotted from all southeast monsoon measurement results are presented in Figure II-126. The surface bay water temperature range is 27.5 ˚C up to 31 ˚C. There are large temperature variations in the layer of 0 to 3 m, and thereafter at the depth layer of 5-20 m the temperature variation becomes smaller, i.e. between 28 to 30 ˚C.
Figure II-126 Temperature Profile (˚C) against the Depth Plotted from All CTD Data Measured During the Southeast Monsoon (Color Indicates CTD Stations)
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Unlike the temperature profile, the salinity profile against depth in Figure II-127 in general indicates that the salinity value at the surface layer is lower than at the deeper layers. This salinity profile was also plotted from all salinity data available during the southeast monsoon. The range of seawater salinity at the surface layer is 19 psu and 30.5 psu. Seawater salinity closer to the bay mouth reached 30 psu, while the salinity value <20 psu was measured in the surroundings of the river estuaries. The seawater salinity value increased along with the increase of depth. At the water depth of >50 m the seawater salinity can reach 30 psu. It can be stated that at the bay floor there are water masses with a salinity of 30 psu.
Figure II-127 Salinity Profile (psu) against Depth Plotted from All CTD Data Measured During the Southeast Monsoon (Color Indicates CTD Stations)
Figure II-128 is a plot of density data calculated from the temperature, salinity and depth at each station where temperature and salinity were measured. As the density is the function of temperature, salinity and pressure, hence masses with density profiles such as illustrated in the Figure can be said that the seawater density in the Bintuni Bay waters during the southeast monsoon are also more dominantly affected by salinity. It can be easily observed from the vertical profiles of density that are more like the salinity profile rather than the temperature profile.
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The smallest density value was measured in the river estuary area, i.e. 1,011 kg/m3 which the salinity value is 19 psu and the seawater temperature is 31.8 ˚C. At the layer with a depth of >50 m the seawater density can reach 1,020 kg/m3.
Figure II-128 Density Profile (kg/m3) against Depth Plotted from All CTD Data measured during the Southeast monsoon (Colors Indicate CTD Stations)
The distribution of the temperature, salinity and horizontal density during the southeast monsoon is presented in Figure II-129 up to Figure II-131. In general distribution patterns of temperature, salinity and density during the southeast monsoon are different from the distribution pattern of same parameter during the northeast monsoon.
Temperature distribution of the bay surface during the southeast monsoon at the southern of the bay is seen to be higher (>30.5 ˚C) than at the northern of the bay. During this monsoon, the temperature in the surroundings of the bay head is seen lower, 28 ˚C (Figure II-129).
Salinity in the surroundings of the river mouths at the bay head part is still seen lower (<22 psu), water masses with a higher salinity (approaching 30 psu) is still seen to occupy the main bay mouth at the southern to extend to the central part of the bay (Figure II-130). At the central part of northern of the bay, water masses distribution with low salinities are also observed (<25 psu), that most likely large masses of fresh water flow from tributaries.
Horizontal distribution patterns of surface density in Figure II-131 is almost equal to horizontal distribution of salinity in Figure II-130, it means that either the northeast monsoon and the southeast monsoon, density of bay waters is still controlled by salinity.
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Figure II-129 Distribution of Seawater Surface Temperature During the Southeast Monsoon as CTD Measurement Results
Figure II-130 Distribution of Seawater Surface Salinity During the Southeast Monsoon as CTD Measurement Results
Figure II-131 Distribution of Seawater Surface Density During the Southeast Monsoon as CTD Measurement Results
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Cross-section of the seawater temperature, salinity and density from the bay mouth to the bay head during the southeast monsoon is illustrated (Figure II-132 up to Figure II-134). The presentation is similar to the above description for northeast monsoon, the y-axis of each figure indicates the water depth (m), the x-axis indicates the distance (km), while the color scale located at the right hand side indicates the value of the temperature, salinity and density of the seawater. The small figure at the lower right hand side is the location map of the temperature and salinity measurement with CTD, while the red line are selected transects to describe the cross-sections of seawater temperature, salinity and density.
Cross-section distribution of seawater temperature from the bay mouth to the head during the southeast monsoon is presented in Figure II-132. A higher water temperature was measured in the layer near the surface in the central part of the bay. The thickness of water mass layers with higher temperatures (>29.5 ˚C) were measured up to a depth of 2 m, thereafter the seawater temperature become 28.5 ˚C at a depth of 5 m. At the bay mouth, the seawater temperature at the surface is higher (28.25 ˚C) with a temperature value at a depth of 20 m is only 28 ˚C.
At the cross-section of salinity from the bay mouth heading to the bay head it is clearly visible that there are salinity gradients. The low salinity water mass (LSW=Low Salinity Water) is seen to be trapped at the end of the bay head (28 psu) due to the strong water mass pushing from the bay mouth direction. The salinity is observed to be increasing at the bay mouth part with a salinity value of >31 psu (Figure II-133).
Similar conditions were also observed at the cross-section of density in Figure II-134 which is identical to the cross-section of salinity described in Figure II-133. The distribution pattern of both parameters is very similar which it means that the water density at the Bintuni Bay waters is controlled by its salinity. Either during the southeast monsoon and the northeast monsoon, the bay water density is dominantly controlled by salinity not by the bay water temperature. The water density value at the river mouth at the bay head is lighter (<1,012 kg/m3) than the central part and the bay mouth (>1,018 kg/m3).
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Figure II-132 Cross-section of Temperature (˚C) from the Direction of the Bay Mouth to the Head During the Southeast Monsoon
Figure II-133 Cross-section of Salinity (psu) from the Direction of the Bay Mouth to the Head During the Southeast Monsoon
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Figure II-134 Cross-section of Density (Kg/m3) from the Direction of the Bay Mouth to the Head During the Southeast Monsoon
Cross-sections of the water temperature, salinity and density also cross the bay, either at the bay mouth (Figure II-132 to Figure II-134) and at the central part of the bay (Figure II-138 up to Figure II-140).
Temperature conditions at the cross-section near the mouth of bay are presented in Figure II-135. From the left to the right hand side or south to the north side. At the north side the seawater temperature appears lower (<27.5 ˚C), while at the south side, the temperature is relatively higher (>29.5 ˚C). This condition is unlike the northeast monsoon with a temperature condition in the central part of bay being in the range of 28.0 ˚C to 29.0 ˚C.
Figure II-136 presents the cross-section of salinity near the bay mouth. In the near- surface layer at the north side of the bay mouth, water masses with a lower salinity (<28 psu) were measured. A high salinity was observed to dominate the section, in particular at the south side of the section. The salinity value can reach 31 psu. When compared to the northeast monsoon, there is a difference in the salinity distribution pattern at the cross-section of the bay. At the northeast monsoon a low salinity water mass was detected in the south side, although it was very thin.
If compared between the cross distribution of density at the cross-section and the cross distribution of salinity, then it is still clearly visible that the bay water density near the mouth is controlled by salinity. Figure II-137 shows the similar distribution pattern to the salinity distribution in Figure II-136. The lighter water mass characterized by a smaller density value (<1,018 kg/m3) is trapped at the north side of the bay mouth where at the same time there is also occurred in the salinity
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distribution. The density value increases towards the south side which is dominated by the seawater mass entering through the inner part of the bay.
Figure II-135 Cross-section of Temperature (˚C) from the North Side to the South Side Near the Bay Mouth During the Southeast Monsoon
Figure II-136 Cross-section of Salinity (psu) from the North Side to the South Side Near the Bay Mouth During the Southeast Monsoon
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Figure II-137 Cross-section of Density (kg/m3) from the North Side to the South Side Near the Bay Mouth During the Southeast Monsoon
Cross-sections of water temperature, salinity and density of the Bintuni Bay at the central part areas during the southeast monsoon is illustrated in Figure II-138 up to Figure II-140. The water temperature of the bay at the central part is relatively homogeneous which is approximately 28.5 ˚C. Only a thin layer is visible in the central part with a temperature of >28.5 ˚C.
The existence of a low-salinity water mass at the cross-section in the center of the bay is increasingly visible. Figure II-139 shows the salinity distribution pattern at the cross-section of salinity in the central part of the bay. At the surface layer low- salinity water mass or LSW= Low Salinity Water (<29 psu) is spread out and widened to the mid sections. Mixing of low salinity and high salinity is visible starting from a depth of 5 m to a depth of 20 m which the salinity value range is at 29 psu and 29.72 psu. Thereafter, the salinity is homogeneous up to the waters floor, i.e. 30 psu.
The same distribution pattern at the cross-section of density has a high similarity with the salinity distribution pattern presented in Figure II-140. Physically it means that the water mass density at the Bintuni Bay during the southeast monsoon is also controlled by the salinity of bay waters. The lighter water mass density (<1,018 kg/m3) is at the northern surface layer and widens to the central part, then slowly rises to 1,018.5 kg/m3 to reach 1,018.75 kg/m3 near the central part of the bay floor.
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Figure II-138 Cross-section of Temperature (˚C) from the North Side to the South Side in the Bay Central Part During the Southeast Monsoon
Figure II-139 Cross-section of Salinity (psu) from the North side to the South side in the Bay Central Part During the Southeast Monsoon
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