The Gombak Operational Unit Finance Essay

Gombak Operational Unit - Slope Assessment Result

As mentioned in Chapter 3, Gombak Operational Unit is managing a total of 380 STPs. Based on IWKs data, 128 STPs out of the 380 STPs have slope issues. This is derived from the assessment done by using the Standard Slope Criteria and Scoring Sheet. The slope assessment results for the 128 STPs were inserted in a Slope Data Scoring Sheet as shown in Appendix 5. A snap shot of the Slope Data Scoring Sheet is shown below in Figure 4.1.

By inserting these data in this sheet, analysis can be conducted individually for the 8 criteria listed in the IWK Standard Slope Criteria and Scoring Sheet.

Findings and Analysis on the Slope Assessment Result

Although the main objective of this research is to identify the most critical STPs based on a risk rating matrix, the author finds that an individual analysis based on the 8 criteria can be done. This will give a general picture on the slope situation faced by the Gombak Operational Unit. The findings and analysis are as below:

STP close to any slopes

Figure 4.2 shows the graph for the first criteria in the IWK Standard Slope Criteria and Scoring Sheet. Based on the graph, 47 out of 128 STPs got a scoring of 5 which means these STPs are located in between slopes (slopes above and below STPs). This is followed by 46 STPs which got a scoring of 2, which means these STPs are located below a slope. Lastly, 35 STPs have got a score of 4 which means these STPs are located above a slope. So it can be concluded that majority of the STPs in Gombak Operational Unit are located in between slopes (whereby there are slopes above and below the STP) which put these STPs in a high risk.

Distance of Slope from STP

Figure 4.3 shows the graph for the second criteria in the IWK Standard Slope Criteria and Scoring Sheet. Based on the graph, 100 out of 128 STPs got a scoring of 5 which means these STPs are located very near to a slope with a distance of less than 5 meters. This is followed by 23 STPs which got a scoring of 4, whereby these STPs are located nearby a slope in range of distance from 5 to 10 meters. There are 3 STPs with a score of 3 (11-20 meters) and 2 STPs with a score of 2 (21-50 meters). Based on the assessment, there are no STPs which are located more than 50 meters from a slope. Therefore, it can be concluded that majority of the STPs in Gombak Operational Unit are located very near to a slope with a range of less than 5 meters and this is considered to be a high risk.

Height of Slope from STP

Figure 4.4 shows the graph for the third criteria in the IWK Standard Slope Criteria and Scoring Sheet. As mentioned before, the higher the score the higher the risk is to the STP. As for this criteria, majority of the STPs falls under the scoring of 1 to 3 (9 meters and below) whereby it is considered in the category of low to moderate risk when it comes to height of a slope. A total of 106 STPs fall under the range of this scoring. 9 of the STPs got a scoring of 4 where by the slopes ranges from 10 to 19 meters high. Only about 13 out of the 128 STPs got a score of 5 where by the slopes located nearby these STPs are more than 20 meters high and it increase the risk to the STPs.

Condition of slope (steepness)

Figure 4.5 shows the graph for the fourth criteria in the IWK Standard Slope Criteria and Scoring Sheet. This criterion focus on the steepness of the slope identified at each of the STPs operated by Gombak Operational Unit. Based on the graph, it can be concluded that majority of the STPs falls under the scoring of 5 which means the slopes identified at these STPs are very steep (>35 degrees). As shown in the graph, 58 out of the 128 STPs are at high risk in terms of slope condition. It is followed by 41 STPs with a score of 2 (<20 degrees) which falls under low risk and lastly 29 STPs falls under the scoring of 3 which is considered to have a moderate risk.

Cover for the slope

Figure 4.6 shows a pie chart for the fifth criteria in the IWK Standard Slope Criteria and Scoring Sheet. This criterion focus on the type of slope protection provided for the 128 STPs identified to have slope issues. Slope with protection (especially structural protection) are considered to be more stable and reduce the risk of landslide or erosion. Based on the figure below, 104 out of 128 STPs were given a score of 3 meaning the slopes identified at these STPs have vegetation as its mode of protection. 22 out of 128 STPS were given a score of 0, meaning the slopes identified at these STPs are covered with structural protection. Lastly, only 2 STPs were given a score of 5 as the slopes identified at these STPS do not have any cover (structural or vegetation) to protect the slopes. Therefore it can be concluded that, majority of the STPs in Gombak Operational Unit have vegetation as their mode of slope protection. This poses moderate risk to the STPs.

Any signs of erosion or damage

Figure 4.7 shows a pie chart for the sixth criteria in the IWK Standard Slope Criteria and Scoring Sheet. Based on the pie chart, 117 out of the 128 STPs identified to have slope issues do not face any signs of erosion or damage. Only a minority of 11 STPs were given a scoring of 5 whereby the slopes were identified to have signs of erosion or damage.

Drainage provided along the slope

Figure 4.8 shows the pie chart for the seventh criteria in the IWK Standard Slope Criteria and Scoring Sheet. Based on the pie chart, 59 % of the STPs with slopes are provided with drainage. Where else, 41% of the STPs with slopes are not provided with drainage system. Although majority of the slopes are provided with drainage, 41% which is about 53 STPs with slopes is considerably a large number which is in high risk due to no drainage system provided along the slopes.

Potential Impact of Slope Failure

Figure 4.9 shows the graph for the eight criteria in the IWK Standard Slope Criteria and Scoring Sheet. Based on the graph below, 54 STPs out of the 128 STPs were given a score of 0,where by the slopes identified at these STPs poses no impact to the STP and its surrounding in any manner if the slope fails. 49 STPs were given a score of 2 which means that the slopes identified at these STPs, will cause minor damage to the STP and it's surrounding if the slope collapse. Out of the 128 STPs, 16 STPs were identified to be located near slopes which will cause major damage (not involving life or property) to the STP and its surrounding if the slope fails. Lastly, 9 STPs were identified to be located near slopes which will create a major catastrophe involving life or property if the slope fails. As a conclusion, a majority of 80% of the STPs are located near slopes which will create no or minor impact to the STP and its surrounding if the slope collapse. Therefore the focus area of IWK is for the balance 20% of the STPs which have slopes that will create a major impact to the company if it fails.

Prioritization of Critical STP Using the Risk Rating Matrix

As mentioned in Chapter 3, by using the risk matrix, the prioritization is given to any STP which the scores fall under the red category (101-175). This means these STPs are considered to be the most critical STPs in terms of slope issues and priority should be given in managing these STPs first. Subsequently, prioritization is given to the STPs for which the scores fall under the green category (51-100) and lastly to the yellow category (0-50) which is considered to have low criticality level. Appropriate mitigation measures are then suggested based on the criticality ranking. Appendix 6 shows the list of Critical STP with Slope Issues which is the result of applying the risk rating formula of "Hazard multiplied with Consequences" on the slope data. This gives a criticality scoring for each of the STPs. After that, prioritization is done by sorting the data from the highest value to the lowest value. The level of criticality for each STP is determined by referring to the risk matrix and a conditional formatting of colour coding is applied to the scoring as per the risk rating matrix. Figure 4.10 shows in a nutshell the summary of the result obtained from the prioritization exercise. The pie chart shows that the total number of STPs operated by Gombak Operational Unit is 380 STPs. Out of the total number of STPs, 128 STPs are identified to have slope issues. Based on the prioritization exercise using the risk rating matrix, 93 out of the 128 STPs are of low level criticality. 21 STPs are in medium level criticality and 14 STPs are in high level criticality.

Focusing down to the 14 STPs which are considered to have the highest criticality level, a summary table was created. Refer to Table 4.1 below.

AMA137 AMA133 AMA112 GUS128 GBK001 AMA087 GBK165 AMA040 AMA141 AMA130 GUS005 GUS110 GBK003 GBK139 As shown in the table above, the STP which has the highest criticality scoring is AMA137 with a total score of 145. This particular STP was given a score of 5 for five out of the eight criteria listed in the IWK Standard Slope Criteria and Scoring Sheet. It is then followed by three other STPs (AMA133, AMA141 and GBK003) with a total score of 125 each. Another three STPs (AMA112, AMA130 and GBK139) have a total score of 120 each. It is then followed by GUS 128, GBK001, GUS005, AMA087, GBK165, GUS110 and AMA040 with the respective scoring as listed in the table above. As predicted, most of these STPs are located at vulnerable areas where major landslides have happened before. The exact location of the STPs can be referred back to Appendix 4. Therefore it can be concluded that these STPs will be the most critical STPs for the Gombak Operational Unit especially AMA137.

Mitigation methods suggested based on the STPs criticality level

Appendix 7 shows the mitigation methods suggested based on the criticality level of the STPs. Some of the suggestions were given by the IWK staffs and some were referred from the "Guidelines on Slope Maintenance in Malaysia, 2006" document. Nonetheless, it is strongly suggested that further investigation need to be conducted to verify these measures before implementing it. For the STPs which are in the high level criticality ranking, the mitigation methods vary based on the 8 criteria. However, most of these STPs need structural protection and also drainage works. Majority of the slopes are located outside the boundary of IWK's plants, therefore it falls under the jurisdiction of the LAs or JKR, and so a joint effort in handling this matter is required. Besides that, a couple of STPs are already in a "Slope Watch Program" which is assisted by the residents around the area to look out for any signs of slope failure. The STPs are namely AMA133 and AMA040. For the STPs which fall under the medium criticality ranking, the author felt that the risk mitigation method could be separated into two methods. For the STPs which scored 80 to 100, the strategy would be to have monthly inspection done, where else for STPs which scored 79 to 51, the strategy would be to have 6 monthly inspections done. This is a practical approach as already the Gombak Operational Unit is facing human resource constraints and by doing a monthly inspection for 21 STPs will increase their burden further. Therefore 8 STPs will undergo monthly inspections and 12 STPs will undergo 6 monthly inspections. But there is one off cases such as AMA048 whereby there is already a strategy in place of rationalizing this plant to a Regional STP nearby; therefore this plant will be soon decommissioned. As for the STPs which are in the low criticality ranking, the strategy to manage the risk is to have yearly inspection done. Table 4.2 shows the summary of the mitigation methods for the slope issues faced by the STPs in Gombak Operational Unit based on the criticality ranking.

Summary of the Results

In Gombak Operational Unit, 128 out 380 STPs have slope issues. Based on the 8 criteria assessed, the slope situation faced by IWK Gombak Operational Unit are stated as below: For STP close to any slope, majority of the STPs (47 out of 128 STPs) falls under the scoring of 5, which means these STPs are located in between slopes (there are slopes above and below the STP) which put these STPs in a high risk. For distance of slope from STP, majority of the STPs (100 out of 128 STPs) falls under the scoring of 5, which means these STPs are located very near to slopes with a range of less than 5 meters and this considered to be a high risk. For height of slope from STP, majority of the STPs were given a scoring of 1-3 meters (which means the slope height is 9 meters and below) whereby it is considered in the category of low to moderate risk. For condition of slope (steepness), majority of the STPs (58 out of 128 STPs) falls under the scoring of 5, which means the slopes identified at the STPs are very steep(>35 degrees) and are at high risk. For cover for the slope, majority of the STPs (104 out of 128 STPs) were given a score of 3 which means these STPs have vegetation as their mode of slope protection and it poses moderate risk to the STPs. For any signs of erosion or damage, majority of the STPs (117 out of 128 STPs) with slope issues do not face any signs of erosion or damage, so it is considered to be at low risk. For drainage provided along the slope, majority of the STPs (59%) identified with slopes are provided with drainage system. But the balance 41% is considered to be quite a large number and needs proper attention.

For potential impact of slope failure, a majority of 80% of the STPs are located near slopes which will create no impact or minor impact to the STP and its surroundings, if the slope collapse. In terms of the prioritization exercise, the summary of the result are stated as below: The total number of STPs operated by Gombak Operational Unit is 380 STPs. Out of the total number of STPs, 128 STPs are identified to have slope issues. Based on the prioritization exercise using the risk rating matrix, 93 out of the 128 STPs are of low level criticality. 21 STPs are in medium level criticality and 14 STPs are in high level criticality. Focusing down to the STPs with high criticality level, AMA137 was identified as the most critical plant for Gombak Operational Unit with a total score of 145. As for the mitigation method, the summary of the result are stated as below: For STPs with high level criticality ranking (101-175), the mitigation method varies for each of the STPs focusing down to the 8 criteria. The main mitigation methods are structural slope protection and drainage system. Besides that is to have a "Slope Watch Program" assisted by the nearby residents. For STPs with medium level criticality ranking (51-100), risk mitigation method could be separated into two methods. For the STPs which scored 80 to 100, the strategy would be to have monthly inspection done, where else for STPs which scored 79 to 51, the strategy would be to have 6 monthly inspections done. For STPs with low level criticality ranking (0-50), the strategy to manage the risk is to have yearly inspection done.

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