DET NORSKE VERITAS TM

Transcription

1 DET NORSKE VERITAS TM English Summary Report ENVIRONMENTAL MONITORING AND BASELINE SURVEYS IN REGION II 2012 STATOIL PETROLEUM AS Talisman Energy Norge AS ExxonMobil Exploration & Production Norway AS Marathon Oil Norge AS Det norske oljeselskap Norway AS REPORT NO./DNV REG NO.: / 14MSJXA-22 REV 01,

2

3 Table of Contents Page PERSONNEL... III 1 INTRODUCTION FIELD WORK STATUS OF REGION II SUMMARY OF THE RESULTS FROM THE MONITORING IN REGION II Rev (former Varg Sør) Varg Sigyn Sleipner Vest Sleipner Øst Sleipner Alfa Nord Glitne Grane Balder Ringhorne Jotun Vale Skirne Byggve Heimdal Volve Vilje Alvheim BASELINE SURVEYS IN REGION II Date : Page ii of iv

4 Preface The environmental survey in Region II 2012 was conducted by Det Norske Veritas in collaboration with MOLAB, and was a part of a major survey coordinated by Statoil s Endre Aas and Rolf C. Sundt. The report summarizes the results from the chemical and physical analyses of the seabed sediments as well as analyses of the benthic macro fauna community in Region II. Personnel Fieldwork: Thomas Møskeland (DNV, survey leader) Christian Volan (DNV, shift leader) Tormod Glette (DNV, shift leader) Jon Kristian Haugland (DNV) Rozemarijn Keuning (DNV) Gunn Mari Michaelsen (MOLAB) Yngve Ildgruben (MOLAB) Rolf C. Sundt was the Statoil representative during the survey Analyses: Grain size distribution: Total organic material: Metals: THC: NPD and PAH: Terje Kolberg, Eli Ellingsen Terje Kolberg, Eli Ellingsen Terje Pedersen, Gunn-Mari Michaelsen, Maja Lisa Olsen, Pål Torgersen, Hanna Skog Lillevik Helene Tvete, Anita Wolff Kalstad, Harald Borud Helene Tvete The chemical analyses were performed at Molab AS, Oslo, Mo i Rana and Porsgrunn. The grain size distribution was determined at Molab AS, avdeling Glomfjord. Biological analyses: Thomas Møskeland og Jon Kristian Haugland (krepsdyr) Amund Ulfsnes (pigghuder, bløtdyr) Per-Bie Wikander, Molltax (bløtdyr) Fredrik Melsom, David Barnes, Øystein Stokland (børstemark, varia) Rozemarijn Keuning (varia) Sorting was conducted at DNV s Biology Laboratory at Høvik. Ludvig Søgnen Jensen and Kasper Nøland were responsible of sorting biological samples. Date : Page iii of iv

5 Univariate analyses: Multivariate analyses: Preparation of report: Chemistry: Biology: Main report: Verification: Project Manager: Lucy Brooks, Thomas Møskeland, Christian Volan Sam-Arne Nøland, Øyvind Fjukmoen, Fredrik Melsom Wenche Brennbakk, Helene Tvete, Hege Karlsen Lucy Brooks, Christian Volan, Fredrik Melsom, Øyvind Fjukmoen, Sam-Arne Nøland Sam-Arne Nøland Øyvind Fjukmoen Thomas Møskeland Date : Page iv of iv

6 1 INTRODUCTION The report presents the results from the regional sediment monitoring in Region II the Sleipner area in The purpose of the regional survey is to study the environmental impacts from petroleum activities at each field and over a larger area. Regional sediment monitoring in the Sleipner area was first implemented in A total of 18 fields, from Rev in the south to Vale in the north, were surveyed. In addition the survey included 6 baseline surveys and 3 new regional stations. The location of the various fields is shown in the map below. Overview of fields included in the monitoring of Region II 2012 and baseline surveys in the region Exsisting fields Baseline surveys Regional stations Date : Page 1 of 23

7 Planned no. of Actual no. of Fields Operator Type stations stations Sleipner Vest Statoil Follow-up 6 6 Sleipner Øst Statoil Follow-up Sleipner Alfa nord Statoil Follow-up 4 4 Glitne Statoil Follow-up 5 6 Grane Statoil Follow-up Heimdal Statoil Follow-up 4 5 Vale Statoil Follow-up 4 4 Volve Statoil Follow-up 6 6 Vilje Marathon Follow-up 7 7 Skirne Statoil(Total) Follow-up 5 5 Byggve Balder Ringhorne Jotun Sigyn Rev Varg Alvheim Regional stations Statoil(Total) ExxonMobil ExxonMobil ExxonMobil ExxonMobil Talisman Talisman Marathon Follow-up Follow-up Follow-up Follow-up Follow-up Follow-up Follow-up Follow-up Dagny Statoil Baseline Eirin Luno/Edvard Grieg Ivar Aasen/Draupne PdQ Draupne/Hanz Isbjørn Statoil Det norske Det norske Talisman Baseline Baseline Baseline Baseline Baseline Regional stations Baseline 3 3 Sum The reporting is divided into three parts. In the Sammendragsrapport (Rapp.nr ) and the Summary Report (this) the main results are presented. The Hovedrapport (main report, Rapp.nr ) contains all the results and review of these. Brief description of the region Region II is located between 58 and 60 N in the Norwegian sector of the North Sea. The water depth of the 2012 stations ranges from 78m to 130m. The major current direction in the region varies; in the Frigg area towards southeast, in the Balder area towards east/southeast and in the Varg area towards north/northeast. This is the sixth regional survey in Region II. 2 FIELD WORK The fieldwork was conducted by DNV in collaboration with Molab from the fishing/research vessel Christina E. The survey, which also included baseline surveys in Region I and IV, was carried out in the period 21. of May to 3. of June The sampling in Region II took place 24. May 1. June. The survey included sampling of sediments for physical, chemical and biological analyses. Sampling and analyses were conducted according to Guidelines for Environmental Monitoring (TA 2848) and internal DNV and MOLAB accredited procedures for such work (Test 083 and 032). A separate survey report has prepared. Station coordinates are given in Appendix 1. Date : Page 2 of 23

8 Total number of stations and analyses included in the sampling- and analyses program in Region II Field Stations Bio Grain/ TOM THC Metals NPD/ PAH Existing fields in Region II Sleipner Vest Sleipner Øst Sleipner Alfa Nord Glitne Grane Heimdal Vale Volve Vilje Skirne Byggve Balder Ringhorne Jotun Sigyn Rev Varg Alvheim Regional stations Sum Region II Baseline Luno/ Edvard Grieg Ivar Aasen Hanz Dagny Eirin Isbjørn New regional stations (for baseline) Sum Baseline in Region II Totalt STATUS OF REGION II 18 existing fields in Region II were analysed for hydrocarbons (THC), NPD, PAH and metals. At 8 of the fields the state of the benthic macro fauna was assessed. The sediments at these fields were characterized by grain size distribution and total organic matter (TOM). In addition baseline surveys were conducted at 6 localities in Region II. Date : Page 3 of 23

9 The 2012 survey in Region II shows: In broad outline the level of THC is lower or at the same level as in The level of barium has increased since The sediments at Region II are dominated by sand and fine sand in all three subregions. The contents of total organic material in the sediments varies from % in the northern subregion, % in the shallow subregion and in the central subregion. The level of THC in the shallow subregion is between 1 and 10 mg/kg. In the central subregion the THC-content is between 3 and 26 mg/kg (except from Ringhorne ekstra with mg/kg). In the northern subregion the THC concentrations is between 4 and 6 mg/kg. Six of the fields show THC > LSC (Volve, Sleipner Vest, Sleipner Alfa Nord, Glitne, Balder and Ringhorne). The highest THC-value is found at Ringhorne ekstra with mg/kg. The Ba-content in the shallow subregion varies from mg/kg. The Ba-content in the central subregion varies from mg/kg, while the northern subregion consists of mg/kg Ba. The highest amount is found at Grane og Ringhorne. Elevated concentrations (>LSC) of barium were found at all fields. The highest Ba-content is measured on RIN-ekstra (5 470 mg/kg), RIN4 (5 192 mg/kg), RIN-5 (4 505 mg/kg) and GRA-15 (3 643 mg/kg). There is an increase in the Ba-concentrations at most of the fields in the region. The THClevels are generally unchanged on all the fields. It is increased PAH and/or NPD levels on 11 out of 18 fields. The majority are relatively low concentrations on the same level as LSC. On Grane all the stations were analyzed for PAH and NPD, and elevated levels were found at 12 out of 15 stations. The highest concentrations were measured at Ringhorne ekstra (3.0 mg/kg PAH and 14.3 mg/kg NPD). There are no major changes in the composition of heavy metals (Cd, Cr, Cu, Hg, Pb, Zn) compared to previous surveys. There is a slight increase of Cr and/or Pb on a few of the stations. The state of the benthic macro fauna was assessed at Rev, Varg, Sleipner Øst and Volve in the shallow subregionen and Grane, Ringhorne, Vilje and Alvheim in the central subregion. The results showed no disturbance of the fauna at any of the fields. Estimated area contaminated with THC is between 1.7 and 5.8 km 2 in Region II. In 2009 the area was estimated to 1 km 2, but the estimates numbers from the two surveys are not comparable. Estimated minimum area contaminated with barium is in the region of km 2 in Region II. In 2009 the corresponding number was 12.8 km 2. The area for Barium is most likely considerably larger than the estimated minimum area. Limits of Significant contamination (LSC) in the northern, shallow and central subregion are shown in the table below. There are small variations compared to previous surveys in the shallow and central subregions. In 2009 LSC for Ba in the shallow subregion was lower than the previous survey and in The 2012 LSC for Barium is at the same level as 2003 and 2006 in the shallow subregion. Date : Page 4 of 23

10 There is an increase in the LSC values in the northern subregion compared to 2009; few regional stations in the northern subregion results in few degrees of freedom and high t-value and thus high LSC for most of the components. Region II, LSC values for 2012, 2009, 2006 and 2003 in the northern, shallow and central subregions values in bold. mg/kg THC PAH NPD Ba Cd Cr Cu Hg Pb Ti Zn LSC northern LSC northern LSC northern < LSC northern LSC shallow LSC shallow LSC shallow < LSC shallow LSC central LSC central , LSC central LSC central The table summarises the most important results from the survey. The most important results from each field are summarised in chapter 4. The baseline surveys are summarised in chapter 5. Grain size and total organic matter (TOM) The region is divided into three subregions (north, shallow and central). The sediments are dominated by fine/very fine sand in all subregions. TOM is in the % range in northern subregion, % in the shallow subregion and % in the central subregion. How to read the box plots Interval with minimum-and maximum value (exclusive outliers and extrema) Total hydrocarbons (THC) Cont. median outliers 50% - interval extremum i.e. 50 % of all stations have medians in this interval Date : Page 5 of 23

11 The level of THC in the shallow subregion is between 1 and 10 mg/kg. In the central subregion the THC-content is between 3 and 26 mg/kg (except from Ringhorne ekstra with mg/kg). In the northern subregion the THC content is between 4 and 6 mg/kg. Six of the fields show THC > LSC (Volve, Sleipner Vest, Sleipner Alfa Nord, Glitne, Balder and Ringhorne). The highest THC-value is found at Ringhorne ekstra with mg/kg. Please note the x-axis jumps from 30 to mg/kg. Baryte barium (Ba) The Ba-content in the shallow subregion varies from mg/kg. The Ba-content in the central subregion varies from mg/kg, while the northern subregion contains mg/kg Ba. The highest amount is measured at Grane and Ringhorne. Elevated concentrations of barium were found at all fields. The highest Ba-content is measured on RINekstra (5 470 mg/kg), RIN4 (5 192 mg/kg), RIN-5 (4 505 mg/kg) and GRA-15 (3 643 mg/kg). Bunnfauna The fauna in Region II is divided into the same subregions as in previous years, and is in accordance with the subregions identified from the other investigated parameters. In general it is considerable variations in abundance and partly number of species between years with accompanying variations in the diversity indices. Similar variations are observed at the regional stations and reflect the natural variation. Of the eight fields were the macro fauna was assessed, no disturbed fauna was revealed. Date : Page 6 of 23

12 4 SUMMARY OF THE RESULTS FROM THE MONITORING IN REGION II 1.1 Rev (former Varg Sør) The sediments at Rev consist of fine sand, and the organic content is low (<1 %). The level of THC is reduced at all stations since 2006 and 2009, and there are no values higher than LSC. Varg S- 10 is the only station where PAH higher than LSC has been found. There is an increase in Ba at all stations, highest at VargS19 (500m S) and VargS3 (500m W). With one exception all Ba-concentrations are higher than LSC. No discharges of barium have been reported since previous survey. There are no other metals higher than LSC. A weak tendency to increased levels of all metals is indicated. The diversity indices of the benthic fauna are somewhat lower than in 2009, but higher than in The Rev field VargS3 is located in the southern shallow subregion, and the results from the regional stations shows large natural temporal variations in this area. There are no indications of disturbance in the benthic community at Rev. The abiotic factors vary marginally within the stations, and the fauna is quite uniform at the four field stations. The fauna in 2012 is more similar to the 2006 than 2009 fauna. Rev VargS19 VargS7 VargS8 VargS Figur Rev The figure shows level of Barium and part of LSC-limit for barium. THC > LSC was not found. Figur THC and Ba at Rev. Date : Page 7 of 23

13 1.2 Varg The sediments at Varg consist of fine sand, and the organic content is low (<1 %). No THC,PAH or NPD-values hihger than LSC have been found and the level of THC is lower than in previous surveys. There is an increase in Ba at all stations highest on VAR11 (250m S). No discharges of barium have been reported since previous survey in With one exception all Baconcentrations are higher than LSC Most of the stations have somewhat elevated concentrations of Cu and Pb. The diversity indices of the benthic fauna are somewhat lower than in 2009, but higher than in As is the case for Rev, Varg is located in the southern shallow subregion, Figur Varg The figure shows level of Barium and part of LSC-limit for barium. THC > LSC was not found. and the results from the regional stations shows large natural temporal variations in this area. There are no indications of disturbance in the benthic community at Varg. Figur THC and Ba at Varg Date : Page 8 of 23

14 1.3 Sigyn Elevated concentrations of THC, PAH or NPD are not found, and all stations have values lower than R2-16. The THC concentrations have decreased since out of 5 stations have elevated Ba-values, the concentrations are at the same level as in The other metals are at the same level or lower than LSC. Biological analyses and sediment characteristics were not included at Sigyn Figur THC and Ba på Sigyn Figur Sigyn The figure shows level of Barium and part of LSC-limit for barium. THC > LSC was not found. 1.4 Sleipner Vest Elevated concentrations of THC were found at two stations (SLV01 and -02) out to 500m N. SLV01 (250m) has elevated concentrations of THC, PAH and NPD, and all metals except for Cd and Ti. Compared to earlier surveys the THC-levels are relatively unchanged except for an increase at SLV01. There is an increase in Ba at all stations, highest towards north (SLV01 and -02). The concentrations of Barium, Cr and Zn are higher than LSC at all stations. There are large temporal variations of Ba. The 2012 results are higher than in 2009, but lower than in Biological analyses and sediment characteristics were not included at Sleipner Vest. Date : Page 9 of 23

15 Figur THC and Ba at Sleipner Vest Figur Sleipner Vest The figure shows level of Barium and LSC-limit for THC. The LSC limit of Ba is outside the image. 1.5 Sleipner Øst The 2012 Sleipner Øst program included only Sleipner A and Loke. The sediments at Sleipner A consist of fine sand, and the organic content is low (<1 %). Elevated concentrations of THC, PAH or NPD are not found, and all stations have values on the same level as the regional station R2-17. There are no major changes in the THC-levels compared to earlier surveys. There is an increase in Ba at all stations, highest at LOK-04 (250m N of Loke) and SLA33 (250m S of Sleipner A). No discharges of barium have been reported since previous survey at Figur Sleipner Øst The figure shows level of Barium. The LSC limit of Ba is outside the image. THC > LSC was not found. Date : Page 10 of 23

16 Sleipner Øst/A. The concentrations of Barium are elevated at all stations, and they are also higher than the regional station R2-17. The other metals are at the same level or lower than LSC. Diversity indices of the benthic fauna at Sleipner Øst are somewhat lower than in As is the case for Rev and Varg, Sleipner Øst is located in the southern shallow subregion, and the results from the regional stations shows large natural temporal variations in this area. The species composition and fauna similarity with the regional stations shows an undisturbed benthic fauna. Like Rev the fauna has more in common with the fauna in 2006 than in Figur THC and Ba Sleipner Øst. 1.6 Sleipner Alfa Nord Elevated THC have been found at three statipns. All field stations have THC at the same level or higher than the regional station R2-18. Compared to earlier years the THC level is relatively unchanged. There is an increase in Ba at all stations, highest at ALF-1 (250m N). All stations containsbarium higher than LSC and the regional station R2-18. The levels of Cr, Cu and Zn are also slightly elevated at most stations. Biological analyses and sediment characteristics were not included at Figur Sleipner Alfa Nord The figure shows level of Barium and part of the LSC-limit for THC. The LSC limit of Ba is outside the image. Figur THC and Ba at Sleipner Alfa Nord Date : Page 11 of 23

17 1.7 Glitne There are somewhat elevated concentrations of THC and NPD at GLI-01 (300m NE), the rest of the stationse have THC, PAH og NPD values lower than LSC. All stationes have higher content of THC than the regional station R2-8. The level of THC has increased at two stations, but the concentrations are at the same level as in There is a small increase of Ba-content compared to previous surveys, with the largest increase on GLI-01. Barium is elevated at all stations and is higher than R2-8. Elevated levels of Cr, Pb and Zn are found at many of the stations. Biological analyses and sediment characteristics were not included at Glitne GLI14 GLI14alt1 GLI10 Glitne GLI1 GLI2 GLI THC: 0,1 km2 Ba: >1,2 km2 Figur Glitne The figure shows level of Barium and LSC-limit for THC. The LSC limit of Ba is outside the image Figur THC and Ba at Glitne 1.8 Grane The sediments at Grane consist of fine sand, and the organic content varies from 1.30 to 2.10 %. There are no elevated concentrations of THC at Grane, and the concentrations are at the same level as the regional station R2-20. The levels are in general unchanged since Elevated values of PAH and NPD are found at most stations. There is a considerable increase in Ba at all stations, which is can be explained by reported discharges of barite. The Ba-concentrations are higher than LSC at all stations. Largest increase is found closest to the platform, and it cannot be ruled out the leakage of injected drill cuttings may have contributed to the increased Ba level. A smaller increase of the other metals is also observed. Date : Page 12 of 23

18 The abundance in the benthic fauna is higher than ever reported at Grane, which results in lower diversity indices than earlier at all stations. The lowest indices were found at two of the stations located closest to the center where a considerable increase in Ba has been observed. The two stations differ from the others because of high abundance of the polychaeta P. jeffreysii, a most common species at several of the fields in the region inclusive the regional stations. A connection between this species and high Barium concentrations has not been revealed, and the fauna at Grane is regarded as undisturbed. Figur Grane The figure shows level of Barium and part of LSC-limit for barium. THC > LSC was not found. Figur THC and Ba at Grane. 1.9 Balder Elevated concentrations of THC, PAH and NPD have been found at two stations, and the levels are in general unchanged compared to previous surveys. There are indications of contamination by olefins (AncoTecB) at BAL-42. The concentrations of Barium are elevated at all stations, and at BAL-37 (250m SE of Balder B) and BAL-42 (250m S of Balder A) the concentrations are considerably elevated compared to 2009 and Elevated values of Cr, Cu og Zn are found at most stations. Biological analyses and sediment characteristics were not included at Balder. There were only two stations located at each of the templates (A and B) at Balder, and no contour plot has been made. Date : Page 13 of 23

19 Figur THC and Ba at Balder 1.10 Ringhorne The sediments at Ringhorne consist of fine sand, and the organic content varies from 1.77 to 2.24 %. Elevated concentrations of THC are found at two stations; RIN4 (250m NE) is at the same level as LSC, whilst RIN-Ekstra (420m W) is considerably contaminated by THC, PAH and NPD. The THC-concentrations are at the same level as in previous surveys at all stations except for RIN-Ekstra where the values have increased with mg/kg since There are elevated values and a considerable increase of Ba Figur Ringhorne The figure shows level of Barium and LSClimit for THC. The LSC limit of Ba is outside the image. at all stations, which is in accordance with reported discharges in the period from the previous survey. RIN-Ekstra contains elevated concentrations of all metals, and an increase of Cr and Pb is seen at all stations. The diversity indices of the benthic fauna at Ringhorne are lower than in 2009, but at the same level or higher than The benthic community at the four stations is uniform and differs from the regional stations because of small variations in the sediment grain size distribution. The analyses indicate a correlation between slightly higher values of Pb at the field stations and differences in the benthic community between field stations and regional stations. However, the variations are small, and the fauna is regarded as undisturbed. It should, however, be included in future monitoring. Date : Page 14 of 23

20 Figur THC and Ba at Ringhorne Jotun Elevated THC is not found at Jotun, and the concentrations are at the same level as the regional station R2-21. The concentrations are unaltered compared to the three last surveys. The concentrations of Ba, Cr, Cu and Zn are elevated at all stations. There is a small increase of Ba at all stations compared to the three last surveys. The concentrations of the other metals are more or less unchanged. Biological analyses and sediment characteristics were not included at Jotun. Figur Jotun The figure shows level of Barium. The LSC limit of Ba is outside the image. THC > LSC was not found. Figur THC and Ba at Jotun. Date : Page 15 of 23

21 1.12 Vale Elevated concentrations of THC are not found, and the concentrations are unchanged compared to previous surveys. The concentrations of Barium are elevated at all stations, and the concentrations have increased at 3 of the 4 stations since 2009, most at VA-07 (250m SW). Biological analyses and sediment characteristics were not included at Vale. Figur Vale The figure shows level of Barium. The LSC limit of Ba is outside the image. THC > LSC was not found. Figur THC and Ba at Vale 1.13 Skirne Elevated concentrations of THC are not found, and the concentrations are unchanged compared to previous surveys. There are relatively high values of Ba at all stations. The concentrations are at the same level as in 2009, when an increase was observed. Biological analyses and sediment characteristics were not included at Skirne. Date : Page 16 of 23

22 Figur THCand Ba at Skirne. Figur Skirne The figure shows level of Barium. The LSC limit of Ba is outside the image. THC > LSC was not found Byggve There is an increase of THC compared to earlier years, but no elevated concentrations of THC are found All stations contain PAH higher than LSC. Barium levels, but no other metals, are elevated at all stations. A considerable increase is observed at BY1 (250m N), but the other stations are unchanged compared to previous surveys. Biological analyses and sediment characteristics were not included at Byggve. Date : Page 17 of 23

23 Figur THC and Ba at Byggve Figur Byggve The figure shows level of Barium and part of LSC-limit for barium. THC > LSC was not found Heimdal Elevated concentrations of THC are not found. Elevated values of av PAH and NPD are found at two stations (out to 500m S). The concentrations of Barium are elevated at all stations, Cu, Pb and Zn at most of the stations. The level of Ba has increased since 2003, at the most at HEIM-18 (300m S). Biological analyses and sediment characteristics were not included at Heimdal. Figur Heimdal The figure shows level of Barium and part of LSC-limit for barium. THC > LSC was not found. Date : Page 18 of 23

24 Figur THC and Ba at Heimdal 1.16 Volve The sediments at Volve consist of fine sand, and the organic content is low (<1 %). Elevated THC-values are found at station VOV1 (250m N). The THC-concentrations are reduced at all stations since The concentrations of Ba and Cu are elevated at all stations. At the stations which had highest Ba-concentrations in 2009, the values have decreased. At the other stations an increase is observed. Volve is located in the southern shallow subregion, and the results from the regional stations shows large natural temporal variations in this area. The temporal pattern with increased abundance and reduced diversity indices that can be seen at Volve corresponds to what can be observed at the regional stations, and is regarded as natural variations. The benthic fauna at the four stations is uniform and undisturbed, and differs slightly from the 2009 fauna. The analyses indicate a possible correlation with higher THC in Figur Volve The figure shows level of Barium and LSC-limit for THC. The LSC limit of Ba is outside the image. Date : Page 19 of 23

25 Figur THC and Ba at Volve 1.17 Vilje Figur 4-3 THC and Ba at Vilje The sediments at Vilje consist of fine sand, and the organic content varies from 1.44 to 1.95 %. Elevated concentrations of THC are not found, and the concentrations of THC have increased at all stations but one. The concentrations of Barium are elevated at all stations but one. The Ba levels have increased at all stations. The largest increase is seen at VIL8 (250m NW). Figur Vilje The figure shows level of Barium and part of LSC-limit for barium. THC > LSC was not found. The benthic fauna at the four stations is regarded as undisturbed. Abundance and number of species have decreased since 2009, resulting in slightly reduced diversity indices. The results show a somewhat different development at Vilje than the nearby regional stations, and the field should be included in future monitoring. Date : Page 20 of 23

26 1.18 Alvheim The sediments at Alvheim consist of fine sand, and the organic content varies from 1.47 to 1.78 %. Elevated concentrations of THC are not found, and the concentrations are unchanged compared to previous surveys. The concentrations of Barium are elevated at all stations. Except for a large increase at KNA12 (250m NW) the Ba-levels are unaltered compared to previous surveys. There are no indications that the benthic fauna at Alvheim is disturbed despite a reduction in number of species and diversity indices since The fauna differs somewhat from the regional stations R2-10 and -21, but his cannot be related to field activities. Figur Alvheim The figure shows level of Barium. The LSC limit of Ba is outside the image. THC > LSC was not found. Figur 4-2 THC and Ba at Alvheim. Date : Page 21 of 23

27 5 BASELINE SURVEYS IN REGION II The 2012 survey from the baseline studies in region II shows: The sediments consist of sand and very fine sand. The Total Organic Matter varies from 0,77 2,45 % The THC-levels varies from <1 10 mg/kg, and there are no significant elevated values compared to LSC. The Ba-levels varies from mg/kg. Most of the stations at Dagny and Eirin have elevated levels of Ba compared to LSC. The benthic fauna in the investigated areas is undisturbed. The most important parameters and variations for each field: Ivar Aasen Variation Description of the field THC (mg/kg) Ba (mg/kg) Diversitet H Diversitet ES 100 Diversitet H Diversitet ES (Draupne) 2 5 (Hanz) (Draupne) (Hanz) (Ivar Aasen) (Ivar Aasen) (Hanz) (Hanz) No elevated THC-levels are found at Ivar Asen compared to LSC. The concentrations are on the same level as the regional station. No elevated Ba-levels are found at Ivar Asen compared to LSC. The concentrations are on the same level as the regional station. The fauna at both localities is undisturbed and characterised by high abundances of some species, which gives moderate diversity indices. This was also the case in Of the three new regional stations R2-14 and -13 are best suited. Both localities belong to the central subregion in Region II. Edvard Grieg Variation Description of the field THC (mg/kg) <1 3 No elevated THC-levels are found at Ivar Asen compared to LSC. The concentrations are on the same level as the regional station. Ba (mg/kg) No elevated Ba-levels are found at Ivar Asen compared to LSC. The concentrations are on the same level as the regional station. Diversitet H Diversitet ES The variations in the fauna are small, and the results show a healthy undisturbed benthic macro fauna. The fauna at the new regional station R2-14 does not differ from the fauna at Edvard Grieg. At the other two new regional stations the fauna is somewhat different, but this is not related to noteworthy differences in sediment characteristics or chemical parameters. Date : Page 22 of 23

28 Dagny Variation Description of the field THC (mg/kg) 5 10 The concentrations are on the same level as the regional station. No elevated THC-levels are found at Ivar Asen compared to LSC, two stations contain 1 mg/kg THC above LSC. Ba (mg/kg) The Ba-concentrations are on the same levels as the regional stations R2-18 and R2-19, but higher than R2-12. Minor elevations compared to LSC are found at 11 stations. Diversitet H Diversitet ES The benthic fauna at Dagny is undisturbed and differs somewhat from the regional stations R2-8 and -18 because of greater water depth and higher content of silt and clay at the Dagny stations. The shallower regional station R2-12 differs from Dagny with regard to sediment characteristics and fauna. This station is not regarded as suited as a basis of comparison for Dagny. Eirin Variation Description of the field THC (mg/kg) 1 9 No elevated THC-levels are found at Eirin compared to LSC. The concentrations are on the same level as the regional stations. Ba (mg/kg) The Ba- concentrations are on the same level as the regional stations R2-18 and R2-19, but higher than R2-12. Minor elevations compared to LSC are found at 12 stations. Diversitet H Diversitet ES The benthic fauna at Eirin is undisturbed and differs somewhat from the surrounding regional stations, which is related to the fact that Eirin is located in a deeper area and the sediments contain a larger fraction of silt and clay. Isbjørn Variation Description of the field THC (mg/kg) 2 6 No elevated THC-levels are found at Isbjørn compared to LSC. The concentrations are on the same level as the regional stations. Ba (mg/kg) The Ba-concentrations are higher than the regional station, but there are no elevated results compared to LSC. Diversitet H Diversitet ES The benthic fauna at Isbjørn is undisturbed. The relatively low diversity indices are similar to other fields and regional stations in the shallow subregion. The fauna differs somewhat from the regional station R2-6 because of differences in water depth and accompanying smaller differences in sediment characteristics. Date : Page 23 of 23

29 Appendix 1 Station coordinates (ED50 UTM, zone 31)

30 REGION II 2012 koordinater Stasjon º / m UTM E UTM N Stasjon º / m UTM E UTM N FRODE Brynhild FR REGI FR REGI FR REGI FR BRY FR BRY FR BRY FR BRY FR BRY FR BRY FR BRY FR BRY FR BRY FR BRY REG BRY BRY BRY Isbjørn Rev IB VargS IB VargS IB VargS IB VargS IB VargS IB VargS IB IB Varg IB Ship (FPU) IB VAR IB VAR IB VAR IB VAR REG VAR VAR Regionale II VAR-14R GRA-14R Reg Reg SIG-17R JO-30R SLE-41R REG ALF-15ref HEM-22R Reg VA-13R BAL-27R Reg

31 Stasjon º / m UTM E UTM N Stasjon º / m UTM E UTM N Sigyn Dagny SIGNY DA SIGNY DA SIGNY DA SIGNY DA SIGNY DA DA Sleipner øst DA Loke DA Sleipner øst DA Sleipner A DA LOK DA LOK DA SLA DA SLA DA4ny SLA-X SLAY Volve SLA VOV SLAZ VOV SLA VOV SLA VOV SLA VOV SLA VOV Eirin Sleipner alpha nord Ei ALF Ei ALF Ei ALF Ei ALF Ei Ei Sleipner vest Ei SLV Ei SLV Ei SLV Ei SLV Ei SLV Ei SLV Ei

32 Stasjon º / m UTM E UTM N Stasjon º / m UTM E UTM N Glitne Hanz GLI H GLI H GLI H GLI H GLI H GLI14ny H H Edvard Grieg H LU H LU H LU H LU H LU H LU LU Grane LU GRA LU GRA LU GRA LU GRA LU GRA LU GRA REG GRA REG GRA REG GRA GRA Ivar Aasen GRA D GRA D GRA D GRA D GRA D D Balder D FPU D Template A D Template B D Template C D Template D D BAL D BAL D BAL D BAL

33 Stasjon º / m UTM E UTM N Stasjon º / m UTM E UTM N Ringhorne Vilje Well head platform VIL Sub sea installation VIL RIN VIL RIN VIL RIN VIL RIN VIL RIN VIL RIN RIN Vale RIN VA RINEx VA VA Jotun VA Jotun A Jotun B Byggve JOT4 22, BY JOT BY JOT BY JOT BY BY Alvheim KNA Skirne KNA SK KNA SK KNA SK SK Heimdal SK HEM Y HEM HEM HEM HEM

34 : DNV is a global provider of knowledge for managing risk. Today, safe and responsible business conduct is both a license to operate and a competitive advantage. Our core competence is to identify, assess, and advise on risk management, and so turn risks into rewards for our customers. From our leading position in certification, classification, verification, and training, we develop and apply standards and best practices. This helps our customers to safely and responsibly improve their business performance. Our technology expertise, industry knowledge, and risk management approach, has been used to successfully manage numerous high-profile projects around the world. DNV is an independent organisation with dedicated risk professionals in more than 100 countries. Our purpose is to safeguard life, property and the environment. DNV serves a range of industries, with a special focus on the maritime and energy sectors. Since 1864, DNV has balanced the needs of business and society based on our independence and integrity. Today, we have a global presence with a network of 300 offices in 100 countries, with headquarters in Oslo, Norway. Global impact for a safe and sustainable future: Learn more on