Turkey - Gas Sector Development Project : environmental impact assessment (Vol. 1 of 4) : Executive summary

TUZ GOLU BASIN UNDERGROUND NATURAL GAS STORAGE PROJECT EIA ADDENDUM EXECUTIVE SUMMARY 1 INTRODUCTION 1202 1.1 PROJECT OVERVIEW Underground storage of natural gas is regarded as an important option for Turkey. With increasing gas consumption, underground storage is needed to balance peak demand with approximately constant gas supply. BOTA,, (Turkish Petroleum Pipeline Corporation) proposes to construct an Underground Natural Gas Storage Facility approximately 200 km south of Ankara in the central part of Turkey, approximately 40 km south of Tuz Golu (or "Salt Lake"): an extensive 162,000 ha salt marsh in the central region of Turkey (Refer to Figure 1 for project location) The Tuz Golu Basin Underground Natural Gas Storage Project (UNGSP) will create a series of underground gas storage cavems by controlled fresh water dissolving of portions of the extensive underground natural salt formations existing at approximately a depth of 1000 m. A geological screening procedure identified Tuz Golu, as the highest priority Turkish site, where salt cavems could be created. It is a favorable site because: (a) it is not far from Ankara, (b) it is close to the Kayseri-Konya-Seydisehir section of existing Eastem Anatolia Natural Gas Main Transmission Line (approximately 19 km) and (c) an extensive formation of pure rock salt with suitable dimensions and mechanical characteristics is available (d) it is the least seismically active region in Turkey. To establish the technical feasibility of the Tuz Golu salt structure, BOTA, evaluated seismic characteristics of the site, mechanical characteristics of the salt cores, and hydrological requirements for leachate water supply and brine disposal. A detailed environmental impact assessment (EIA) study was conducted to satisfy Turkish Environmental regulatory requirements. The EIA was officially approved by the Ministry of Environment and Forestry (MoEF) on 19.08.2003. 1.2 PROJECT DESCRIPTION The salt domes are located at approximately 700 m depth, have a thickness of 700- 1500 m, and will be leached using fresh water supplied from the Hirfanli Dam (see Section 1.2.1(a) below). The brine (solution) resulting from leaching operations will be discharged to a well defined and officially approved area within Tuz Golu (see Section 1.2.1(b) below). It is planned to open 12 caverns each having approximately 500,000 m3 of volume and with a natural gas storage capacity of approximately 80x10o m3 (with maximum PAGE 1115  TUZ GOLU BASIN UNDERGROUND NATURAL GAS STORAGE PROJECT 0 t EIA ADDENDUM EXECUTIVE SUMMARY compression, 205 bar) While some of the caverns are opened (construction activity) on one hand, it shall be initiated to store natural gas into the caverns already opened (operation activity) on the other hand. During storage of natural gas, the natural gas shall be compressed by means of compressor and injected to the caverns. In future years, new cavems can be opened if modifications in the national natural gas policy of Turkey recommend such an option. Completion of the construction phase is expected to take approximately 10 years and the project economic lifetime is estimated to be 50 years. 1.2.1 Key project components (a) Fresh Water Supply Line Fresh water will be used for leaching the salt cavems. Initially, local groundwater was considered for the fresh water source to open caverns as groups of 2. BOTA, later on, to speed up the project implementation, decided to open caverns as groups of 4 instead of 2, which doubles the fresh water demand of the project. However, groundwater shortage was one of the major concerns raised during the first Public Consultation Meeting. As a consequence, BOTA,S (although there exist no problem for allowance of such an amount of water from groundwater resources by DSI) revised the project design to utilize Hirfanli Dam reservoir located 115 km from the project site as a fresh water source. DSI (State Hydraulic Works), the authority responsible for the water resources allocation in Turkey, provided their official approval for use of the required 10-1 2x1 06 m3/yr water from Hirfanli Dam. Hirfanli Dam, constructed in 1960, is one of the major multi-purpose dams in Turkey, which is used for energy and irrigation. It receives an annual inflow of approximately 2400x1 O6 m3/yr. The water demand of the project, 10-1 2x1 06 m3/yr, is less than %0.5 of the inlet flow to the dam reservoir. Therefore, DSI stated that they have no difficulty in supply of this arm,ount of water over the project life and, in addition the existing and future energy and irrigation based projects will not be affected adversely. Water will be transported by an underground pipeline of approximately 115 km to the project site. The pipeline will be transferred to DSI after the completion of the project to be used for water supply and/or for the irrigation, which will be beneficial for the local people. PAGE 2/15  TUZ GOLU BASIN UNDERGROUND NATURAL GAS STORAGE PROJECT EIA ADDENDUM * 0* EXECUTIVE SUMMARY 1 2 ..* ----.. ~--- 9 1 P.UR ~ A P ' .7AWJARA 1~~~~~~~~~~~~ KOtTYA~~~~~~~iud ' i \ s r , \ g ffi o. ~~~~~~ ~ ~~KazDkit Own e ++t I Z 7k':sI - < , s ~~~~\ ot.rmu