MANAGING OF ENVIRONMENTAL IMPACTS DURING PROSPECTING AND EXPLORATION FOR OIL AND GAS – IMPLEMENTATION OF GOOD INTERNATIONAL PRACTICE

sources (EPA, USA). The main activities were described, the possible accidents that may occur (accidental spills and blowouts) were presented as well as the typical environmental impacts that may be caused during oil and gas exploration and production activities. The possible environmental impacts were identified based on the detailed information received from the Client for the planned seismic surveys for oil and gas prospecting and exploration and for the type of the vibrators that are planned to be used. A review was done of the methodology of the applied in the past exploration works and it was established that in the past the territory of Golitsa Blocks (B-Golitsa and B-1 Golitsa) had been subject to geological mapping in different scales and extensive specialized oil and gas prospecting and exploration activities many times such as: geophysical surveys, drilling of prospecting and exploratory wells. The available information showed that seismic surveys within the territory of Golitsa Blocks had been conducted in the past applying different methodologies depending on the international practice in geophysics for the specific time period. The second step involved documentary study of the available information to collect detailed information for the environmental baseline conditions within Golitsa Blocks territory. The extracted data were systematized, analyzed and summarized thus giving reliable information about the state of environment on the territory of Golitsa Blocks with respect to the different environmental components before new exploration and production activities for oil and gas had started. Tables, drawings and maps were prepared for illustrating the environmental state with respect to the different components. Climate conditions in the area were characterized as well as Fig. 1. Location of Golitsa Blocs air quality features, the state of groundwater and surface water, the land and soils, geology, flora and fauna, landscape as well as cultural and historical heritage. The following main conclusions about the environmental conditions were drawn up on the basis of the data from the documentary study:  The meteorological conditions in the area of Golitsa Blocks are relatively good for dispersal of pollutants during most time of the year. The ambient air pollution on the territory of Golitsa Blocks and the adjacent regions is irregular in character. Considerable air pollution is established in the easternmost area of the Block (regions of towns Varna and Devnya), while in the regions of the other towns it is considerably lower and insignificant (the country regions).  Several rivers cross the territory of Golitsa Blocks among them Kamchiya river is the biggest. The river together with its tributaries and gullies cuts significant part of the investigated area. Due to the construction of dams, many microdams and riverbed corrections the rivers in the Blocks have disturbed runoff regime.  Various in age and lithological composition rocks outcrop in the region and are complicated by the occurrence of tectonic processes.  Mainly watertight rocks and complexes outcrop in the territory of Golitsa Blocks, where the groundwater has sporadic occurrence and is related to intercalations of sandstone and limestone situated between marl and clays. Relatively more water-abundant are the alluvial deposits of the river terraces as well as the karst basins with Upper-Cretaceous – Paleocene age and the Paleogene aquifers in the Lower Kamchiya Depression. In depth, in the northeastern part, the Paleogene groundwaters (Eocene and Oligocene) in the Moesian Platform and the Lower Kamchiya Depression are of hydrogeological concern as well as the ones formed in the Lower Cretaceous –Upper Jurassic rocks in the region of Varna town.  Nine main soil types and 22 soil sub-types occur within the territory of Golitsa Blocks, out of them five are in a complex with other types or sub-types. Thousands hectares of arable land have been irreversibly lost due to anthropogenic impact (not related to past oil and gas exploration activities). Degraded and contaminated lands and soils were established in some areas of the Blocks, mainly in Devnya lowland.  The biodiversity within the territory of Golitsa Blocks is very rich. The variety of relief forms and the different climatic influences in the vicinity of the sea along the eastern border of the Blocks and in the high mountainous parts in its western parts determine the opulence of vegetation communities and animal species occurring there. Rich diversity of protected flora and fauna species was registered. Thirty protected areas are situated within Golitsa Blocks –1 reserve, 5 maintained reserves, 14 protected areas, 4 natural sites and 6 important bird areas.  2951 monuments of architecture, archeology, art, history and culture protected by the Bulgarian legislation fall within in the territory of Golitsa Blocks. The third step covered terrestrial field surveys that included expert specialized studies and observations on the environmental state in the specific locations of the planned future seismic surveys within Golitsa Blocks: landscape, flora and fauna, surface and ground water, presence of contaminated land along the planned seismic line locations, existence of characteristic geological structures, etc. The new seismic activities were planned along lines with total length of 170 km and along these the observation routes were organized. Old drilling sites were visited that were established during the terrestrial field surveys. The information obtained during the terrestrial field surveys was systemized and analyzed. The results showed that in general the locations of all planned seismic lines were in relatively clean regions. Only in some very small in size areas communal and construction wastes were scattered. Summary of the obtained results is presented below: - Within the studied area forest and forest-meadow landscapes dominate along the routes of the seismic lines. Sections of the lines cross areas with agricultural plantations –perennial and annual. Depending on the applied methodology and techniques for seismic survey at some places will be necessary to make cuttings. - Century old tree species grow between Bardarevo and Solnik villages as well as in the State Game Farm “Sherba” and Forest Farm “Genishada”. One seismic line (011 07 04) passes through a section with century old oaks near Bardarevo village. - The pastures situated to the east of Kozichino village (crossed by seismic line 010 07 04) and to the west of it (seismic line 008 07 04) are habitats of species with very high protection status. - The future seismic lines cross the rivers Kamchiya, Eleshnitsa, Chairdere, Lekarnitsa,

Armerea, Ploska reka, Fandakliyska as well as the adjacent gullies or pass along the river valleys. - Shallow occurrence of groundwater in the terrace of Kamchiya river has imposed construction of drainage network in its lower current. Two seismic lines (001 07 04 and

07 04) cross such drainage channels at several points. - The studied area is characterized with relatively low water abundance. In the vicinity of the future seismic lines at some places there are blowouts that caught groundwater of springs with small or insufficient flow rate. Insufficient water occurrences are observed in draw- wells. In the region around the end of one seismic line (010 07 04), near Kozichino village, small springs and swampy areas caused by shallow groundwater were observed. - The future seismic lines will cross rocks with different age and lithological structure. A considerable part of seismic lines 007 07 04, 008 07 04 and 011 07 04 pass through flysch sediments. The prevailing part of seismic lines 001 07 04, 002 07 04 and 003 07 04 are situated over the non-coherent terrace deposits of Kamchiya river. The northern end of seismic line 008 07 04 passes not very high rock cliffs of Upper Cretaceous carbonate sediments. - The existence of 13 old wells for oil and gas prospecting and exploration conducted in the past have been established in the vicinity of seismic lines 002 07 04, 003 07 04 and

07 04. Over-flow wells were reconstructed as water sources with troughs for cattle watering place. At two of the wells traces of old drilling sites were observed. No traces of previous contaminations were registered around the old wells. The forth step included identification of the expected environmental impacts with respect to the different components: - Ambient air quality: During seismic surveys some air pollution with emissions from diesel engines of the heavy off-road vehicles where the vibrators are mounted was expected to occur. - Surface and ground water: No potential impacts on the surface waters and groundwater during conducting of seismic surveys (no matter the type of elastic waves generation) were expected. - Land and soil: The impacts on land and soil resulting from seismic surveys were expressed during their three fazes: (1) During tracing of the seismic lines: Damages to land and soil appear as disturbance (removing of soil layers when constructing temporary roads) and degradation (disturbance of soil structure - trampling of these roads and around them). The extent of compaction depends on the grain size composition of the soil, the season when works take place, the kind and number of vehicles and other machinery used, and the number of staff, passing over, as well as the duration of road usage; (2) During invoking elastic vibrations via vibrators the main soil characteristics are not altered in principle with the exception of the surface layer (0-5 cm) – morphological changes. As a result of and depending on the the number of vibration impact and mechanical pressure of seismic vibrators in unfavourable sense some important from agronomic point of view soil parameters are changed which define degree of momentary usage of potential fertility of various kinds of soils: the volume density of the soil in the ploughing layer between 0 and 30 cm increases by 30%; the total porosity of the soil in the ploughing layer decreases to critical values; the quantities of valuable from agronomic point of view soil aggregates with size from 0.25 to 10 mm decrease while the aggregates with size over 10 mm increase with up to 50% which leads to soil structure defragmentation; the extent of changes of the soil properties after vibration and seismic impact depends on the humidity of soil and the character of soil coverage. (3) During auxiliary activities - shallow drilling for exploration of the weathering zone: The damages here are mainly in a form of disturbance and some contamination of land and soils in the area of the drilling mud pits. - Geological settings: Geophysical prospecting and exploratory works practically do not influence geological basement due to their character of remote methods. - Flora and fauna (the major impacts): The planned seismic lines crossed mainly forest and forest-meadow landscapes while the agricultural landscapes cover comparatively small areas. Therefore it would be necessary to make cuttings, including cuttings in old forests with century old trees. The analysis of the available data showed that the damages to vegetation resulting from the geophysical (seismic) works were reversible and the affected areas usually self-recover quickly. In the region of “Ticha” summer house zone crossed by seismic line 003 07 04 two plants with conservation importance (Aurinia uechtritziana (Born) Cullen et Dudley, Centaurea arenaria Bieb. Ex Willd) were established. In the region of Kozichino village, crossed by seismic line 008 07 04, another plant also with conservation importance was established (Anthemis virscens Velen). Pastures around the villages represented habitats of plant species with very high protection status. The planned seismic lines crossed several protected areas, as follows: - Seismic lines 007 07 04, 011 07 04 and 003 07 04 entirely crossed the IBA “Kamchiyska planina” while only sections of seismic lines 008 07 04, 010 07 04 and 0ХХ 07 04 cross it; - Sections of seismic line 001 07 04 crossed the IBA “Kamchiyska planina”, and “Kamchiya Complex” without entering the protected area “Kamchiyski pyasutsi”; - Seismic line 002 07 04 passed between IBA “Kamchiyska planina” and “Kamchiyski Complex”, closer to the second one; - A section of seismic line 011 07 04 passed through the maintained reserves “Vulchi prohod” and “Vurbov dol”; - Maintained reserve “Vulchi prohod” was crossed by sections of seismic lines 008

04, 010 07 04 and 0ХХ 07 04 and seismic line 007 07 04 passed very close to it; - Natural Site “Siniyat vir” was located between seismic lines 007 07 04 and 008 07

Cultural and historical heritage: the seismic sources and the seismic surveys in general may have turned to have adverse impact on the historical and architectural monuments situated in the vicinity of the seismic lines. The planned routes of the future seismic lines also crossed several areas with registered monuments of culture. These are: - Seismic line 011 07 04 passed the southern part of Burdarevo village. One Late- antique fortress and 7 historical houses are registered in the region of this village; - Seismic lines 010 07 04 and 011 07 04 passed close to Golitsa village. In this region are registered 5 historical places, one Late-antique fortress, a church and 2 historical houses; - Seismic line 011 07 04 started near Rudina village where a mill house and 5 historical houses are found; - Seismic line 001 07 04 crossed Staro Oriahovo village where a church and 4 historical houses are registered; - Seismic line 002 07 04 passed the northeastern end of Novo Oriahovo village. In the region of the latter a church, school and 3 historical houses existed. During the fifth step recommendations were given as well as measures that should be implemented in connection with the forthcoming seismic works for oil and gas prospecting and exploration in Golitsa Blocks, with the objective of environmental protection:  New cuttings in the preserved old forests were undesirable. Existing roads should be used, vulnerable in faunistic aspect sections of the lines should be avoided;  Special attention should be paid to the forest phytocenoses, because there are several plants with conservation status.  Shrubs and offshoot forest should not be cut off. There are many species with conservation status also on the limestone rock cliffs. The majority of psamophyte and halophyte species are also with conservation status. Special attention should be paid to the century-old wood species –between the villages of Bardarevo and Solnik, in the territory of the wood-producing company Sherba and the forestry Genishada.  Century old oaks near Bundarevo village should not be cut off for the purposes of seismic survey of line 011 07 04. The group of several tens of a century old trees and can be bypassed;  The unique faunistic diversity of the riverine forest in the lower current of Kamchiya River has been described in chapter 4.7.3. Therefore, new cutting, parallel to the road will be not be necessary if seismic line 001 07 04 enters the riverine forest from the direction of Staro Oryahovo village, using road E-87 Burgas-Varna. At point 170 on the western side of the road another cutting starts. It is strongly recommended to use this cutting instead of making new one as follows from the planned route of this seismic line.  Seismic line OXX 07 04 crosses hunting reserve “Sherba”. Survey should be compulsory coordinated with the management body of the reserve since safety issues are concerned. This is area of intensive international hunting activity. It is of great importance to avoid any accidents or possibilities for temporary game expel due to the noise of surveying machines.  Pastures around Kozichino village are used intensively and two of the seismic lines –

07 04 (to the east of the village) and 008 07 04 (to the west of the village) cross them. These pastures are habitats of the following species with very high protection status: European souslik (Spermophilus citelus), Isabelline Wheatear (Oenanthe isabellina) and Lesser Grey Shrike (Lanius minor). In this respect it is recommended to cross these areas only by using existing roads without set up of any temporary resting places or camps.  During seismic surveys special attention should be paid on the terrains with surface erosion.  Future seismic lines 003 07 04 near Shkorpilovtsi village and the end of 008 07 04 should not cross the sanitary protection zones of the constructed in the area pump stations for drinking water supply.  To limit the degree of agricultural soil compaction it is recommended to conduct the seismic surveys with vibrator at a value of soil humidity not more than 70-80 % of the maximum field water capacity.  When soils are over moisturized (humidity 85-100 % of the maximum field water capacity) seismic surveys using vibrators should be avoided due to the risk of their deterioration for longer period –two years and more.  If hesitation for presence of cultural monument near the seismic line arises consultants- archeologists from the Regional museums of Varna or Burgas should be contacted.  For the purposes of environmental protection temporary camps and resting places for workers must be well organized: - Spills of fuel and lubricants must be avoided, their containers should not be placed in the soil, in the gullets or in the surface water streams; - The temporary sites should cover the least possible areas; - Soil compaction result of surveying machinery must be reduced to the minimum; - Communal wastes generated on the site should be collected and transported to the appropriate landfill place. In the presented in the Ministry of Environment and Water technical project for carrying out of the seismic surveys in Golitsa Blocks a special section was included describing the measures related to environmental protection and restoration and management of communal and technological waste generated during the surveying works. The last sixth step included review of the implementation of the proposed measures and evaluation of the real environmental impacts. During the field works the surveying teams strictly followed the environmental protection requirements for collection and removal of the domestic and technological waste generated on the terrain. In view of creation of optimal recreation conditions it was decided not to establish temporary camp for the geophysical team, which for this reason was accommodated in a hotel in Shkorpilovtsi village. The selected alternative replaced the need to search for a solution for collection and treatment of the generated domestic waste. The assessment of the real impacts on the environmental components showed the following: - Ambient air quality: During the carried out seismic surveys there was short term ambient air pollution from the emissions generated by the diesel engines of the seismic vibrators as well as from the engines of the servicing trucks and cars. As it was mentioned above this impact has been short-term and limited in scale. It should be added that the main share of the used trucks were relatively new, the vibrators themselves were completely new and their engines comply with the EU requirements with respect to emission of exhaust gases. - Surface and ground water: The seismic surveys carried out practically have no influence on surface water. During the carried out drilling of shallow boreholes (upholes) for exploration of the weathering zone all necessary measures for protection of groundwater from eventual pollution were undertaken. Overflow of groundwater was established in two of the drilled in total 35 boreholes. Measures to drain the overflowing groundwater into the nearest river were applied in these boreholes; concrete shafts were constructed with lids in order to facilitate the eventual use of the groundwater by the local population. - Land and soil: In order the impacts resulting from the seismic activities on land and soil to be minimal the routes of the seismic lines were selected in such a way that their main part to pass along existing roads of the national road network and respectively along field and forest dirt roads. The period for conducting of the seismic activities was planned for the end of summer and beginning of autumn when that main share of the agricultural crops had been already collected and in such a way the possible damages to the agricultural production and soils was avoided. All necessary measures were taken for reclamation of the drilling sites after the drilling of shallow boreholes (upholes) for exploration of the weathering zone. - Geological settings: The seismic surveys carried out due to their character of a remote method do not influence the geological settings. Insignificant in scale impact on the geological settings was caused during the drilling of the shallow boreholes (upholes) for exploration of the weathering zone. After finishing of the exploration works these boreholes were liquidated in a suitable way and the necessary reclamation activities were carried out on the sites of the boreholes. - Flora and fauna: The routes of the seismic lines were planned in such a way so that the main part to pass along existing roads. Practically no special cuttings were made in the forest section and the seismic works in the sections with agricultural crops were carried out after the agricultural goods were collected in order the damages to the agricultural production and respectively to the agricultural land to be minimal. Insignificant in scale damages were caused only to insignificant in size area (strip with width 4 m) in several fields, planted with corn as their owners were compensated in appropriate way. The negative impact of the carried out seismic activities on the fauna (mainly from the noise of the vibrator’s engines and the servicing trucks) was limited in area and for a very short period. - Cultural and historical heritage: The seismic surveys were planned in such a way that the routes of the seismic lines would not pass closely to monuments of the cultural and historic heritage. Based on the analysis of the results of the baseline environmental study within the boundaries of Golitsa Blocks as well as on the results of the field investigations and the site visits of the locations of the seismic lines it could be concluded that the carried out seismic surveys have had insignificant, short-term and limited in area and magnitude environmental impacts. The authors express their thanks to the management of Balkan Explorers Bulgaria Ltd for the kind permission to present the results of the assigned to GeoMarine Centre Ltd baseline environmental study in Golitsa Blocks in the present paper.