4 Site Selection
4.0.1 The site selection of the water-sealed cavern storage shall comply with the requirements specified in the industrial plan and the related HSE requirements，and be carried out according to the conditions in terms of meteorology，hydrology，transportation，water supply，power supply，communications，and land in the region where it will be located.
4.0.2 The storage site shall be close to the available storage and transportation facilities such as wharf，oil depot，and pipeline.Besides，and the storage site should be located in a region where there is a huge crude oil or oil product demand and intensive imported oil processing.
4.0.3 The gedogical and hydrological conditions of the water-sealed cavern storage shall comply with the following requirements:
1 The rock mass shall have high hardness，high integrity，and high stability，without any tensile fractures.Its mineral constituents shall not affect the quality of the stored crude oil or oil product.
2 In the cavern storage area，there shall be a stable ground water table.The underground rock mass's permeability coefficient shall be lower than 10-5m/d.
3 The water inflow volume of the blocked cavern storage should not be higher than 100m3/d every 1Mm3 capacity.
4.0.4 The water-sealed cavern storage shall not be located in one of the following areas:
1 An earthquake area in which there are earthquake-inducing faults or whose basic earthquake intensity is 9 or above；
2 A water source conservation area；
3 A national nature reserve.
4.0.5 The minimum distances from the water-sealed cavern storage's surface facilities to surrounding residential areas，industrial enterprises，transport lines，etc.shall comply with Table4.0.5.The distances that are not listed in the table shall comply with relevant requirements specified in the currently effective national standard Code for Design of Oil Depot（GB 50074）.
Table 4.0.5 Minimum Distances from Water-sealed Cavern Storage's Surface Facilities from Surrounding Residential Areas，Industrial Enterprises，Transport Lines，etc.
Table 4.0.5（Continued）
Notes:1 Starting and end points of the distances are as shown in Appendix A.
2 The shafts and vapor recovery units shall be located at least 30m from 35kV or above overhead power lines in addition to complying with the No.9 requirement in the above table.
3 The buried cables outside the water-sealed cavern storage used for a purpose rather than the cavern storage shall be located at least 3m from the enclosing wall of the cavern storage.
4 Typically，the involved industrial enterprise is a one that is not engaged in oil storage.If it is also an oil storage enterprise and，they are built simultaneously，then the distance between the two storages shall be twice or above the cavern span，and a vertical water curtain shall be set up in between；otherwise，the later-built oil storage's access tunnel portal shall be located at least 300m far away from the underground facilities of the oil storage that has been built，and a vertical water curtain shall be set up between them，depending on the hydraulic analysis.If the involved industrial enterprise has a surface oil tank farm close to the underground oil storage，the minimum separation distance between the adjoining oil tanks shall be 1.5 times the diameter of the largest oil tank but at least 30m，the minimum distances from other adjacent buildings and structures of the industrial enterprise shall be 1.5 times the minimum distances specified in Table 6.2.1，and its minimum distance from the industrial enterprise's flare facility shall comply with the table.
5 Its minimum distance from any blasting site is considered to start from its enclosing wall.
6 The flare may be one that carries an flammable liquid.For other flares，its minimum distances from buildings and structures outside the oil storage shall be determined through the calculation of radiant heat.
7 In case of blasting operations outside the oil storage area，the earthquake effect of the cavern tanks shall comply with the relevant requirements in the currently effective national standard Safety Regulations for Blasting（GB 6722）.