**2. Engineering approaches**

*Geopolymers and Other Geosynthetics*

of the Gulf War with approximately 49 km<sup>2</sup>

*Volume of oil trenches and oil lakes in Kuwait (source: [9]).*

left to be recovered [9].

**Table 1.**

mately 49 km2

hard, tar-like dry surface layer. Four categories of oil-contaminated soil layers, namely, soot, tar mat, oil lake, and dry oil lakes, were identified during the field investigation. The fifth category is clean, where no contamination was detected. As illustrated in **Table 1**, it is fortunate that the Kuwait Oil Company (KOC) has been successful in recovering around 21 million barrels from the oil lakes since the end

Dry oil lakes 25 98.38 25.5 Wet oil lakes 64 7.19 4.6 Oil-contaminated piles 173 8.59 14.8 Oil trenches and pipeline spills 351 1.63 5.7 Total 115.79 49.6

**Source of contamination Average depth (cm) Extent (km2**

This catastrophe has created one of the greatest environmental impact issues to the coast, air, soil, groundwater, and the vicinity. In addition, it has been noticed that the oil lake depth varies from a few metres to a few centimetres, which constitute more than 60 million barrels of crude oil. Overall, almost 660 million barrels of crude oil were spilled to the surface, and therefore, around 55 million tons of contaminated sand is present in the lakebeds. The persistence of such a phenomenal amount of oil over a large land area is considered as one of the main environmental concerns in the State of Kuwait. There are no similar petroleum catastrophes in history that has ever been as tragic as this incident [6, 7]. Furthermore, approxi-

which constitutes 28% of the total Kuwait land area was covered

by oil mist and soot. As time goes by, lighter oil evaporated, oil mist became hard, while smaller and shallower oil lakes became dry thus forming tar mats. Under the extreme weather conditions, these contaminants continue to disintegrate slowly. The thickness of tar mat varies from a few millimetres to approximately 2 cm. The soot changed the soil beneath to black in the long run. It has been found by investigator Kwarteng [7] many of these oil lakes could not be detected from the surface since they were covered with a veneer of sand. Moreover, the author noticed in the different effected area of Kuwaiti desert that, the occasional flash floods and heavy showers were placed when the oil travelled to new sites. There are limited large-scale remediation processes implemented to deal and treat the contaminated areas thus far. The Kuwaiti environment is exposed to these oil contaminated soil and oil lakes since 1991 therefore the contamination is become a weathered oil contamination, which is required special strategy to deal with this disaster. The State of Kuwait is considered as the first country in the world who filed claims from the United Nations Compensation Commission (UNCC) for seeking compensation to rehabilitate and remediate the areas that sustained environmental damage. In 1991 UNCC had decided to sell Iraqi oil for distributing money as recompense "the money to be taken from the Oil-for-Food Programme" for damages suffered from the Iraq invasion. In 2003, the pace of the clean-up is anticipated to significantly increase over years of researches and claims. The UNCC awarded the state of Kuwait about US\$3 billion in order to rehabilitate the effected area in the Kuwaiti desert during the Gulf War [3]. The KOC, UNCC, and Kuwait National Focal Point (KNFP) are providing the combined effort for the rehabilitation task. Currently, KOC is planned to coordinate bidding for contracts worth hundreds of millions of dinars in the upcoming months which will remain afterward every year. According to experts, the entire process

of oil lakes with 16.5 × 106

m3

**) Volume (×106**

 **m3 )**

in volume

**150**

"Soil remediation" is referred to as the efforts which aim to reduce or remove the risks related to the contamination site. This objective can be easily achieved by using various ways; however, the most appropriate remediation method is governed by many factors, such as the conditions of site, financial constraints, and category of contaminants. Nathanail and Bardos [10] proposed that the remediation process can take place by degrading, removing, or transforming contaminants to the acceptable level. In situ and ex situ remediation process for rehabilitation of weathered oil-contaminated soil can be classified based on their treatment process, for instance, biological, chemical, physical, thermal, and electrical [11]. A number of various methods of remediation are presently available. Remediation techniques such as soil vapour extraction, bioremediation, electrochemical remediation and electrokinetic soil remediation, and ex situ soil washing have been developed lately in an effort to remediate soils contaminated with petroleum [12, 13]. In accordance with Ellis et al. [14], appropriate engineering solutions should be taken into account to ensure the remediation zone is contained and migration of leachate beyond the treatment zone is avoided. Should the conclusion require soil remediation, it should be tackled after the evaluation of technologies. The following outlines the soil remediation technology in comparison with the typical treatment approach. This includes remediation technologies that can improve the quality of soil through design and application which are central to soil clean-up process. The remediation is achieved by reducing or removing contaminations such as total petroleum hydrocarbons (TPHs), volatile organic compounds (VOC), semi-volatile compounds (SVOC), and metal contents.
