Hydrocarbon storage in unlined rock caverns in Greek limestone A.G. Benardos * , D.C. Kaliampakos School of Mining and Metallurgical Engineering, National Technical University of Athens, GR 15780, Athens, Greece Received 21 March 2004; received in revised form 13 July 2004; accepted 18 August 2004 Available online 18 October 2004 Abstract The existence of tank farms in the vicinity of cities is a principal component of the urban vulnerability and risk conditions. Even if such environments have been accepted in the past, the enforcement of stricter environmental legislations and the emerging of a strong public opposition towards this co-existence, usually result in the relocation of the facilities. Nevertheless, the relocation proc- ess has to overcome a great deal of issues, such as high land cost and strong opposition from neighbouring communities, that often hinder or might even postpone the whole project. Answer to such standstill cases can be given by the development of underground complexes that can facilitate the storage requirements, efficiently and with enhanced environmental protection. Hence, the first area that should be considered for the tank farm relocation is found right beneath the existing facilities. This paper presents the Greek experience, paying special attention to the storage facilities found in the Perama area. The development of an underground storage complex is proposed in that particular area, which could finally offer a viable solution, satisfying the interests of all involved parties. The unlined caverns are to be excavated in limestone bedrock and the characteristics of this alternative are illustrated in detail, fol- lowed by the comparative cost analysis between the underground scheme and the surface relocation of the tank farm to another area in Attica. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Underground oil storage; Unlined rock caverns; Limestone; Cost comparison 1. Introduction The development and evolution process in urban cen- tres, most of the time, leave their mark and characterise the existing environment. Thus, it is common to find growing communities near industrial sites that have been established there in the past. Nevertheless, this co-existence is not always developing under ideal neigh- bouring conditions and conflicts may arise. This is inten- sified in cases of heavy industrial installations or hazardous materials industries, located near the urban fabric (Perrow, 1999). The ‘‘shanty towns’’ once estab- lished to facilitate the industries, have gradually evolved to booming urban centres which find that their future development is hindered by those installations. In this manner the same facilities that once sustained that local urban sprawl, nowadays have become the greatest threat to the very existence of the communities. A typical case of such installations are oil refineries and oil storage facilities. The use of aboveground steel tanks for the storage of oil and other petroleum products is the predominant practice worldwide (Myers, 1997). Even though they are highly efficient and provide easy handling of the stored product, their impacts on the envi- ronment and on the safety of the neighbouring activities gave rise to serious protests and public distrust. During the past decade, a number of stricter environmental reg- ulations, e.g. Seveso II directive 96/82/EC, (ECCD, 1996) have been issued and as a result new land use planning guides have been drawn (ISIS, 1999). Nevertheless, even with the effect of these new standards, there are cases, in existing tank farms, where the current placement of the 0886-7798/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.tust.2004.08.005 * Corresponding author. Tel.: +30 210 7722182; fax: +30 210 7722156. E-mail address: abenardos@metal.ntua.gr (A.G. Benardos). www.elsevier.com/locate/tust Tunnelling and Underground Space Technology 20 (2005) 175–182 Tunnelling and Underground Space Technology incorporating Trenchless Technology Research