The application of HAZOP and BowtieXP methodologies of risk assessment using the Macondo oil well blowout as a case study has been investigated. This study is aimed, to compare and contrast between the HAZOP and BowtieXP methodologies of risk management using the Macondo oil well blowout as a case study. Hence, to accomplish the set aim of the study, the study envisions the Macondo oil well blowout as a scenario, which objectively vector: to evaluate risk management of the Macondo blowout using the Bowtie methodology; to assess risk management of the Macondo blow out using the HAZOP methodology; to prioritize risk assessment methodology within the risk management process; and to show the causes, failed controls, top event, impact, and consequences of the Macondo oil well blowout. To perform the Bowtie Analysis, several steps were followed to ensure an accurate representation of the Bowtie Diagram. Firstly, The TOP EVENT was established. This was the most critical step in Bowtie XP Risk tool. The choice of the TOP EVENT was guided by some questions: What is the risk event? At what point was the safety control lost? At what point did the root causes lead to, and that eventually results in the top event? Next, the preceding events and root causes threats were established. The choices made addressed answered the aforementioned questions relating to the risk controls which failed, the human factors and behaviour which played a role in the elevation of danger and the root causes of the Top Event. This study concludes that the major event of drilling an oil well is a BLOWOUT, which may lead to a catastrophe, and this was identified by both the HAZOP and BowtieXP as STUDY NODES and TOP EVENT, respectively. The consequences of a failed control blowout are Fire, Explosion, Fatal loss of lives, and environmental pollution.

Two main sources of water (the surface water and underground water) were briefly discussed in this paper. Filtration which is a very significant treatment process for both surface water and underground water was also discussed. A portable tubular filter pipe for borehole water purification system was designed and fabricated. The materials used in the portable tubular filter pipe (sand layer depth of 0.15m of size 0.8-2mm and coarse gravel layer depth of 0.02m of size 5-8mm) were sourced locally. The coarse aggregate (gravel) layer served as support and distribution of water while the sand layer served as the filter medium. The diameter of the portable tubular filter pipe was assumed to take 4 inches PVC diameter pipe (0.1016m). The design reveals that the filter area is 0.0479m 2 , the flowrate in the filter is 8 x 10-5 m 3 /s, the filter volume is 0.02m 3 and the headloss in the filter is 0.5m. Materials used for the fabrication of the portable tubular filter pipe are PVC materials that are easily available in water treatment stores. Tests were carried with the fabricated portable tubular filter pipe on borehole water. The results show that the portable tubular filter pipe performed relatively well in purifying borehole water.