Full Report - Feasibility Study KSCS K-Exim

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 2.3 Raw water allocation plan The total amount of raw water available is 17.9m3/sec, which is 14.6m3/sec from Karian Dam and 3.3m3/sec from Pasir Kopo dam. The amount to be sent to the left side area of Karian dam, which is not included in this project, is 5.5m3/sec, and the amount of raw water supplied to the right side area of Karian dam through the Carian-Serpong water pipe line, which is included in this project, area is 12.4m3/sec. <Table 4> shows the plan of raw water allocation by phase, and the raw water supply plan to each water treatment plant is shown in <Table 5> and <Figure 2>. <Table 4> Raw water allocation by region (Unit: m3/sec) Karian Karian dam + Pasir Kop dam Area Service area Total Planned WTP Phase1 Phase2 Phase2 Phase2 Karian PK Subtotal Total 17.9 14.6 0 3.3 3.3 Total 12.4 6.55 2.55 3.3 5.85 Subtotal 8.0 3.15 2.55 2.3 4.85 Tangerang 1.3 2.45 Solear 3.6 1.15 1.15 regency Right Banten Domestic South 1.8 0.65 0.65 0.5 1.15 side of province water Tangerang 1.25 the city Serpong Karian Tangerang 0.5 2.0 0.75 0.75 dam city Lebak 0.6 0.6 - - Rangkas regency - Bitung/Maja West Bogor regency 0.2 0.2 - - - Parung Java Panjang Jakarta West Jakarta 4.2 3.2 - 1.0 1.0 Serpong Total 5.5 8.05 -2.55 - -2.55 Left Banten Domestic Subtotal 1.5 1.5 - - - side of province water Serang 0.7 0.7 - - regency 0.3 0.3 - - - Not included in the Serang city 0.5 0.5 - - the project area Karian Cilegon city dam - (Petir) - Channel flow for 4.0 6.55 -2.55 - -2.55 Ciujung river maintenance * Of the supply capacity of raw water for the first phase (14.6 m3/sec), the construction is planned to be done only for the amount to be supplied to the Serpong WTP for the first phase (4.6m3/sec). 8

Summary Report <Table 5> Raw water allocation plan by WTP (Unit: m3/sec) WTP Total Water allocation plan Phase 2 Service area m3/sec m3/day m3/sec m3/day Phase 1 m3/sec m3/day Total 13.9 1,200,960 8.05 695,520 5.85 505,440 Rangkas 0.4 34,560 0.4 34,560 - - Lebak regency Bitung Maja 0.2 17,280 0.2 17,280 - - Lebak regency Solear 3.6 311,040 1.15 99,360 2.45 211,778 Tangerang regency Parung 0.2 17,280 0.2 17,280 - - Bogor regency Panjang Serpong Tangerang city, South 8.0 691,200 4.6 397,440 3.4 293,760 Tangerang city, West Jakarta Not included in this project Petir 1.5 129,600 1.5 129,600 - - (Serang city, Serang regency, Cilegon city) ** Of the supply capacity of raw water for the first phase (14.6 m3/sec), the construction is planned to be done only for the amount to be supplied to the Serpong WTP for the first phase (4.6m3/sec). <Figure 2> Raw water allocation plan by project phase 9

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 3.0 Related facilities and plans 3.1 Facilities and plans related to conveyance pipeline This project is a project to construct water conveyance pipelines, a part of the water supply system that aims to provide water to the country’s densely populated areas including the capital city of Jakarta. The planned conveyance system takes raw water from the Karian Dam currently under construction at the upstream of the Ciujung river in West Banten province, Java, which is a source of water, and delivers water to the Serpong water treatment plant slated to be constructed through PPP project as well as other to-be-built water treatment plants in the neighborhood. Current status of related facilities is shown in <Table 6>. <Table 6> Current status and plans of conveyance-related facilities Classification Upstream facilities This project Downstream facilities Facility Karian Dam Conveyance pipeline Water treatment plant Related Intake tower Phase 1 Phase 2 Serpong WTP facilities Conveyance tunnel Rangkas Bitung WTP Booster pump Branch Maja WTP Solear WTP station pipeline Parung Panjang WTP Main pipeline PPP project to be implemented Current status To be completed EDPF - by October 2019 PPP Financing (plan) EDCF 3.2 Water source and intake plan In 2004, the Indonesian government asked the South Korean government for technical assistance for the Karian Dam project, which is located in Kalaha block, Rangkasbitung, Lebak regency, Banten province. With a grant aid, South Korea’s international cooperation agency KOICA carried out a supplementary work for the feasibility study, prepared a detailed design from 2004 to 2006. To finance the amount needed to start construction, the Indonesian government signed an EDCF loan contract with the South Korean government in 2011 and closed a construction deal with South Korea’s construction company for a five-year construction period. Now the dam is under construction for the completion by October 2019. The project development details are as shown in <Table 7>, the aerial view and cross-section of the dams are as shown in <Figure 3>. 10

Summary Report <Table 7> Specifications of Karian Dam Facility Classification Content Location ∙ The Ciberang River (branch of the Ciujung Basin area River) ∙ Kalaha block in Rangkasbitung, Banten province ∙ 288km2 Type ∙ Central Core Rockfill Dam (C.C.R.D) Karian Specification (length/height) ∙ L=514m, H=63.5m Dam Annual average rate of flow ∙ 20.2m3/sec ∙ 15.93km2 (high water level in normal times) Storage area ∙ 314.71 million m3 Total ∙ 207.48 million m3 ∙ 60.80 million m3 Storage Effective storage ∙ 46.40 million m3 capacity Flood control storage ∙ 14.6m3/sec - Serang: 5.5m3/sec Drought storage - Tangerang: 9.1m3/sec Water supply Drought water level ∙ EL (+) 37.50m Water Low water level ∙ EL (+) 46.00m level Normal water level ∙ EL (+) 67.50m Flood water level ∙ EL (+) 70.85m Maximum water level ∙ EL (+) 71.22m Source: Karin Dam related data extracts (March 2018, The Korea Rural Community Corporation) <Figure 3> Aerial view and cross section of Karian Dam 11

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 3.3 Intake tower In order for the water treatment plant to take raw water stably, the intake tower is planned to be installed on the right bank of the Ciberang River and connected to the Ciuyah conveyance tunnel, a discharge facility. The intake tower is a self-standing structure that allows an operator to take water selectively according to the water level. The effective diameter of the planned intake tower is 6m in order to take water of 12.4m3/sec (1,071,360m3/day), the amount needed to KSCS. This amount includes supply capacity of 3.3m3/sec (285,120m3/day) of the Pasir Kopo Dam after its construction is completed. <Figure 4> General drawing of intake tower <Table 8> Specifications of intake tower Facility Classification Content Location ∙ the right bank of the upper stream of the dam Intake type ∙ Multi-hole Tower structure ∙ Self-standing structure Intake Specification ∙ External diameter 9.6m× height 30.1m (ID 6.0m) facility Design capacity ∙ 12.4m3/sec Intake range ∙ LWL: EL.46.0m, FWL: EL.67.5m Sluice gate ∙ Sluice gate 1 El. (+)61.0m, Sluice gate 2 El. (+)56.0m elevation ∙ Sluice gate 3 El. (+)51.0m, Sluice gate 4 El. (+)46.0m Source: Master planning and PPP Development Scheme of the Karian Dam – Serpong water conveyance system and water treatment plant construction project (2015, The Export-Import Bank of Korea) 12

Summary Report 3.4 Conveyance tunnel The Ciuyah conveyance tunnel is a facility connected to the suction pipe of a booster pump station, which supplies an allocated quantity of water to the eastern region once the water resource is secured after the completion of the Karian Dam. The capacity of the conveyance tunnel is planned at its maximum discharge capacity of 12.4m3/sec (1,071,360m3/day), by taking into account the intake tower’s capacity of 9.1m3/sec(786,240m3/day) and the additional capacity of 3.3m3/sec(285,120m3/day) following the completion of the Pasir Kopo Dam. The tunnel, which measures 4.0m in diameter and 1,329m length, is planned to be made up of concrete with the design velocity of 1.0m/sec. The terminal point of the tunnel is to be connected to the steel pipe with a length of 5m, whose diameter gradually decreases from 4,000mm to 3,200mm so that the tunnel is connected to the conveyance pipeline with a diameter of 3,200mm. The bottom elevation of the entrance of Conveyance Tunnel is El.(+) 42.80m, and the bottom elevation of the exit is El.(+)42.56m. The altitude difference between entrance and exit is 0.24m and the slope is 1 / 5,000. <Figure 5> Longitudinal layout of the conveyance tunnel Source: Master planning and PPP Development Scheme of the Karian Dam – Serpong water conveyance system and water treatment plant construction project (2015, The Export-Import Bank of Korea) 3.5 Water treatment plants After the consultation with BBWS C3, an Indonesian governmental agency, five water treatment plants – Rangkasbitung, Maja, Solear, Parunggg Panjang, and Serpong – are confirmed to be connected to the conveyance pipeline. Of which, a plan for the Serpong water treatment plant is developed as a PPP contract by the Korea Water Resources Corporation, South Korea’s governmental agency for water resources development, and it is currently waiting for the Indonesian government’s approval. The other four plants have yet to lay out any development plan. 13

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 9> Administrative districts and geographical conditions in WTP sites WTP sites Province Regency/City District Slope (˚) Sea level (m) Serpong WTP Banten Tangerang Serpong 1 - 3 47.0-53.0 Solear WTP Banten Tangerang Cisoka 3 - 6 46.0-58.0 Banten Lebak 0 - 1 69.0-72.0 Rangkas West Java Bogor Rangkas 1 - 3 53.0-60.0 Bitung WTP Banten Serang Bitung Parung -- Parung Panjang Panjang WTP Maja Maja WTP 4.0 Raw water conveyance system planning 4.1 Conveyance system by phase The conveyance system is planned according to the project’s target year (by 2021 for the first phase and by 2031 for the second phase.) The first pipeline of the main conveyance pipeline with a diameter of 2,000mm and a length of 47.9km is planned to provide raw water of 6.55m3/sec (565,920m3/day) to five water treatment plants (Rangkas Bitung, Maja, Solear, Parung Panjang, and Serpong.) The second pipeline of the main conveyance pipeline with a diameter of 1,800mm to 2,000mm and a length of 47.9km is planned to provide raw water of 5.85m3/sec to two water treatment plants (Solear and Serpong). The conveyance system plan by phase is shown in <Table 10>. <Table 10> Conveyance system plan by phase Classification Target Main pipeline Branch pipeline Phase 1 year ∙ 1st conveyance line: 47.9km - 2021 - D2,000mm, L=47.9km ∙Branch conveyance pipeline: Phase 2 2031 ∙ 2nd conveyance line: 47.9km 19.31km - D2,000mm, L=36.0km - D1,800mm, L=11.9km - D1,350mm, L=4.75km (Solear) - D600mm, L=8.56km (Rangkas Bitung) - D600mm, L=4.80km (Parung Panjang) - D350mm, L=1.20km (Maja) 14

Summary Report Except for Rangkas Bitung water treatment plant which has a high ground level, it is planned to supply to each branch water treatment plants both the first and second phases by branch pipelines on main pipeline, and single hydraulic system with dual pipeline by inter-connecting between two main pipelines in order to supply raw water without interruption in case of an accident. The conceptual diagram of the single hydraulic system with dual pipeline is shown in <Figure 6>. <Figure 6> Single hydraulic system with dual conveyance pipeline The single hydraulic system with dual pipelines has a number of merits as follows: (1) The pipeline can be recovered without interruption of water supply in case of emergency The conveyance pipelines are subject to unexpected accidents such as a pipeline damaged by an external shock or leakage at a corroded area due to the deterioration. Hence, the dual conveyance pipeline is the best solution to control accidents in the pipeline, which allows one pipeline to keep supplying water while the other line is under the repair work, without suspending water supply service. (2) A periodic inspection can enhance reliability of the system To prevent against accidents and extend the service life of the pipelines, an inspection of the system including check valve, air valve, drain valve, telescopic pipe, flowmeter, and water 15

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia hammer protection device, needs to be conducted on a regular basis. Sometimes, such a periodic inspection may interrupt the operation if necessary, however, the dual pipeline does not require any interruption of service by checking two pipelines alternately. (3) Economic operation A combined hydraulic system standardizes water pressure inside the pipeline, thereby reducing the peak head found in the single pipeline. A reduced peak head means lower probabilities of leakage accidents and less power consumption as well as less operating costs by reducing wasted residual head. In other words, an economic operation can be achieved. This system can reduce the pump head from 50m to 45m by making Single hydraulic system with dual conveyance pipeline. According to the existing report for basic design and PPP basic plan on Karian – Serpong water conveyance and supply system (2014 report), a high-head pump system with a height of 86m is planned to supply raw water to the Serpong and Parung Panjang water treatment plants whereas a low-head pump system with a height of 47m is planned to supply raw water to the Solear water treatment plant. The concept diagram is thought to be as shown in <Figure 7>. <Figure 7> High and low head separated hydraulic system A high and low head separated hydraulic system causes an interruption of water supply service for long hours if any periodic inspection of the pipeline or a repair work is needed in case of a leakage accident. Furthermore, when the system is extended in the second phase, each facility needs to be extended, which will increase construction costs. 16

Summary Report The conveyance system plan by phase is as described in <Figure 8>. <Figure 8> Conveyance system plan by phase 17

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 4.2 Pump plan for a phased conveyance (1) Booster pumps The number of pumps is decided by considering the amount of water to be conveyed in each phase as well as stand-by pumps for potential breakdown or checkup. Considering the initial load flow amount and flow control of a small-scale WTP’s (such as Maja and Parung Panjang WTPs) and responsiveness against flow rate fluctuations, pumps are classified as main pump, regulating pump, and Rangkas Bitung system pump. The capacity and number of pumps are planned as in <Table 11>. <Table 11> Flowrate and number of booster pumps Base Phase Conveyance Pump flowrate and number of units amount Phase 1 6.15m3/sec Operation 1.0m3/sec.unit x 6 units (6.55m3/sec) Standby + 0.5m3/sec.unit x 1 unit = 6.5m3/sec 1.0m3/sec.unit x 1 unit POLA Phase 2 Rangkas Bitung Operation + 0.5m3/sec.unit x 1 unit = 1.5m3/sec (5.85m3/sec) 0.4m3/sec Standby Operation 0.40m3/sec.unit x 1unit = 0.4m3/sec 5.85m3/sec 0.40m3/sec.unit x 1unit = 0.4m3/sec Standby 1.0m3/sec.unit x 5unit Total 12.0m3/sec Operation + 0.5m3/sec.unit x 1unit = 5.5m3/sec (12.4m3/sec) Standby 1.0m3/sec.unit x 1 unit + 0.5m3/sec.unit x 1unit = 1.5m3/sec Phase 1 Rangkas Bitung Operation (4.6m3/sec) 0.4m3/sec Standby 1.0m3/sec.unit x 11unit Operation + 0.5m3/sec.unit x 2units = 12m3/sec 4.6m3/sec 1.0m3/sec.unit x 2units Standby + 0.5m3/sec.unit x 2units = 3m3/sec KSCS Operation 0.40m3/sec.unit x 1unit = 0.4m3/sec Standby 0.40m3/sec.unit x 1unit = 0.4m3/sec Final 12.0m3/sec (12.4m3/sec) 1.0m3/sec.unit x 5 units + 0.5m3/sec.unit x 1 unit = 5.5m3/sec Rangkas Bitung Operation 1.0m3/sec.unit x 2 unit 0.4m3/sec Standby + 0.5m3/sec.unit x 1 unit = 2.5m3/sec 1.0m3/sec.unit x 11unit + 0.5m3/sec.unit x 2units = 12m3/sec 1.0m3/sec.unit x 2units + 0.5m3/sec.unit x 2units = 3m3/sec 0.40m3/sec.unit x 1unit = 0.4m3/sec 0.40m3/sec.unit x 1unit = 0.4m3/sec For a stable conveyance, the pump equipment is planned with a system that is reliable and stable, satisfies the planned amount and water pressure, and includes pipelines. The number of units that meet the planned conveyance amount by phase, discharge flowrate, head, and rated power for a booster pump is decided as shown in <Table 12>. 18

Summary Report <Table 12> Types and specifications of a booster pump Classification Main pump Regulating pump Rangkas Bitung System Type Double suction volute Double suction volute Double suction volute pump pump pump Flowrate 60m3/min (1.0m3/sec) 30m3/min (0.5m3/sec) 24m3/min (0.4m3/sec) Head 50m 50m 52m Rated power 700kW 350kW 320kW No. Phase1 7 (including 1 standby) 2 (including 1 standby) 2 (including 1 standby) of Phase1 units Total 6 (including 1 standby) 2 (including 1 standby) - 13 (including 2 standbys) 4 (including 2 standbys) 2 (including 1 standby) According to the existing report for basic design and PPP basic plan on Karian – Serpong water conveyance and supply system (2014 report), five units of high head pumps (86mH x 1,500kw), five units of low head pumps (47mH x 750kw), and two units of Rangkas Bitung system pumps (375kw) were planned, but the specifications of these pumps were not specified. Given the insufficient information about the flowrate and units of pumps, it is difficult to make a precise judgment. But one thing is clear. A combined operation with high and low head pumps in the single pipeline, as proposed in the 2014 report, is deemed impossible. Installing the least number of large capacity pumps may save some space in the pump station, however, little room for flow control reduces the responsiveness against fluctuations in flowrate. Hence, a large number of units of pumps with the same head are planned in this feasibility study to effectively respond to demand changes. (2) Layout of pumping station The layout plan of the pumping station is shown in <Figure 9>. <Figure 9> Pump station layout plan 19

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia (3) Pumps selection in consideration of water level variation in Karian dam The water level at the dam is designed to change by up to maximum 21.5m, between high water level of (+) 67.5m and low water level of (+) 46.0m depending on whether it is drought or rainy season. In this feasibility study, the hydraulic calculation is made based on the mean water level of (+) 56.4, the most frequently operated level, and the corresponding pump head is determined. In this case, the pump still deviates from the operating line when operated at the high and low water levels, but given the low frequency of such cases, it is deemed not to disrupt the operation of the pump station as a whole. <Figure 10> Water levels and elevation of the pumping station ∇H.W.L.(+)67.50 G.L.(+) 45.97 ∇M.W.L.(+)56.43 ∇L.W.L.(+)46.00 C.O.P. Booster BOT El.(+)42.40 El.(+) 42.67 Pump To WTP Bottom El.(+)40.87 Karian Dam Booster Pumping Station <Figure 11> shows an efficiency curve of the pumps produced by South Korean pump maker H. Line A is an operating point at the mean water level, line B is an operating point at the high water level, and line C is an operating point at the low water level of (+) 46.0m. To show a chart of operating points, the curve C-A-B is an performance curve at phase 1 and the curve C0-A0-B0 is an performance curve at phase 2 with the integrated operation. The pump performance at each stage is as shown in <Table 16>. Although there is a problem that the pump flow rate decreases at low level, but it is necessary to consider that it is an emergency period in which the frequency is not high. <Table 16> Changes in pimp operating point depending on water levels of dam Water level at dam(m) Phase 1 Flowrate Pump head H.W.L (+)67.5 38.93m 4,500 CMH (1.25 CMS) M.W.L. (+)56.43 50m 3,600 CMH (1.0 CMS) L.W.L (+)46.0 60.43m 2,500 CMH (0.70 CMS) 20

Summary Report <Figure 11> Efficiency curve and operating line of the booster pump (4) Review of pump station plan proposed in the 2014 report The 2014 report on Master Planning of Karian – Serpong Conveyance System and Water Treatment Plant PPP is as follows: The booster pumping station consists of ten axially split volute pumps in total, five high pressure pumps for pumping from the Serpong WTP to the Parung Panjang WTP and additional five low pressure pumps for pumping to the Solear WTP. The facility planning is as follows: • Serpong and Parung Panjang WTPs’ pumping capacity: 6m3/s • Solear WTP’s pumping capacity: 2.3m3/s • One suction pipe, one transmission pipe, and one appurtenance • One crane It is difficult to make an estimation since the specifications of pumps are not specified in the design drawing. Estimations based on floor plan and design descriptions of electric work are as follows: 21

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia • High head pump: 1.5m3/sec (90m3/min) x 86mH × 1,500kW × 5 units • Low head pump: 0.575m3/sec (34.5m3/min) x 47mH × 750 kW × 5 units • Rangkas Bitung system pump (flowrate and head not available, 375 kW × 2 units) The layout plan of the pumping station presented on PPP report is shown in <Figure 12>. <Figure 12> Previously planned layout of pump station (2014 report) ① the future plan for the expansion of the conveyance amount was not established. The current total amount of 8.3m3/sec (excluding Rangkas Bitung System conveyance amount of 0.4m3/sec), which combines 6.0m3/sec of the high head pump and 2.3m3/sec of the low head pump, needs to be increased to 12.0m3/sec for phase 2. ② the conveyance pipelines for both high and low head pumps are 2,000mm in diameter. This means the gap in the conveyance amount between the high head pump with 6.0m3/sec and low head pump with 2.3m3/sec was not considered. ③ the heads for the high (87m) and low (47m) pumps were calculated too high. It needs a pressure reducing device to reduce the residual head of the WTP inlet. ④ interconnecting the conveyance pipelines does not mean anything since it is impossible to operate high and low head pumps together in the single conveyance system. ⑤ the flowrate of the high head pump is 1.5m3/sec (129,600m3/day), which is quite a large volume. However, with no regulating pump planned, it is difficult to respond to small changes in conveyance amount of the small-scale WTP connected by the branch pipeline. 4.3 Hydraulic calculations (1) Determination of water level for hydraulic calculations Water levels at the Karian dam vary greatly from (+)67.5m in high water level to (+)46.0m in low water level, with the difference of 23.5m. Theoretically, hydraulic should be calculated based on the low water level, the worst-case scenario; however, doing this makes the required pump head too high, leading to an excessive residual head even in normal operation. Therefore, the hydraulic for this project is calculated based on the mean water level of (+)56.43m and the extreme values such as H.W.L and L.W.L are planned to be adjusted within 22

Summary Report the range of a natural pump operating line. The pipeline route plan is as shown in <Figure 13>. <Figure 13> Planned route of the conveyance pipeline As shown in <Table 14>, the required head for water treatment plants is calculated by adding 2.0m of head needed for water treatment facility to the required head for the conveyance pipeline. <Table 14> Required head for WTP Classification Serpong Rangkas Bitung Maja Solear Parung Panjang Conveyance Pressurize at Branched at Branched at Branched at Sta.14+253 Sta.18+582 Sta.30+334 Overview pipeline booster - Tangerang Bogor regency Sta.74+925 pumping station regency Parung Panjang 0.2m3/sec South Lebak regency 46.0m Cisoka district district 1,200m Location Tangerang city Rangkas Bitung Serpong district district Planned daily 0.4m3/sec 3.6m3/sec 0.2m3/sec maximum 8.0m3/sec water supply Elevation 50.8m 72.1m 46.0m 58.3m 4,750m 4,800m Pipeline length 47,925m 8,560m 23

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia (2) Review of hydraulic calculation results In the hydraulic system, it is the most ideal that residual head is minimized at all end points thus there is no residual loss. The results of the hydraulic calculation based on the residual head at the inlet of the water treatment plant are summarized in <Table 15>. <Table 15> Residual head at the inlet of WTP Phase 1 Single operation of the Interconnected operation phase 2 pipelines of the phase 2 pipelines WTP Residual Action Residual Action Residual Notes Rangkas Bitung head taken head taken head (m) (m) (m) 2.50 - Not - 2.50 - connected - Maja 17.79 PRV 13.52 PRV Not connected Solear 30.95 PRV 26.24 PRV 11.16 PRV - Parung Panjang 4.58 - Not - 3.2 - connected Serpong 2.0 - 9.75 - 0.92 - In general, it is desirable to have dual pipelines which allow the other pipeline to keep conveying water in the event of failure of one pipeline. There are relatively high levels of the residual head at the inlet of the Maja and Solear WTPs. However, if an interconnected operation of the first and second phase pipelines is conducted, which is our final goal to achieve, all of WTPs will be operated stably with no excessive residual head. Pressure reducing valves will be installed at the inlet of the water treatment plant. This allows an operator to directly measure the inflow rate and residual head for an appropriate control of the operation. If these valves are installed in the conveyance pipelines, there may be a confusion between the conveyance pipelines trying to reduce pressure and the water treatment plant trying to control inflow rate. Therefore, a WTP project provider needs to consider installing pressure reducing valves when planning the WTP. In a 2015 report on master planning of Karian – Serpong conveyance system and water treatment plant PPP, a high head (87m) and low head (47m) pumps are planned to be operated separately. In this case, it is impossible to combine the operation of the high and low head pumps, which in turn makes the interconnected operation of two dual line pipelines an impossible option. That is, an enormous amount of money invested in the construction of two dual line conveyance pipelines would only end up being useless because the two pipelines do not complement each other. Therefore, a more enhanced plan is established in this study. 24

Summary Report To stably supply water to each water treatment plant, the required pump head is 50m, enough for the first phase and for the second phase case 1. For the second phase case 2, the pump head of 45m is needed. Pressurization with the pump head of 45m makes more economic sense than pressurization with the head of 50m, hence, it is deemed reasonable to operate with the head of 45m designed for the second phase case 2. To operate the system as case 2, the interconnected pipelines, which connect the first pipeline to the second one, are planned. The flow rate and water pressure are planned to be adjusted in each pipeline, as well. 4.4 Pipe wall thickness When determining the thickness of the installed steel pipe, it is necessary to consider factors including internal pressure, external pressure, differential settlement, and seismic load. The thickness of the steel pipe must be greater than the minimum thickness, less than 5 percent of the deflection by internal/external pressure, less than 0.1 percent of the axial deflection caused by differential settlement, and no more than 0.3 percent of the axial deflection caused by seismic load. The allowable tolerance for the thickness in the production of the steel pipe must be ±50 ㎛ and less, but this is not taken into account when deciding the thickness. The thickness of the straight pipe is calculated according to the applied water pressure and surrounding conditions for each section, and the results are shown in <Table 16>. <Table 16> Thickness review Applied water pressure Applied Thickness of pipe (mm) Applied (kgf/ cm2) cover depth steel pipe Diameter (mm) Maximum Maximum (m) Required Nominal type hydrostatic hydrodynamic thickness thickness (KS) D2,000 10.00 D1,800 pressure pressure 10.00 7.59 15.0 type B D1,350 10.00 5.77 13.0 type B D600 10.63 5.91 10.00 4.69 10.0 type B D350 10.00 2.08 6.0 type A 7.49 5.91 1.22 6.0 type A 7.67 4.45 7.43 6.11 6.34 5.29 4.5 Auxiliary facilities (1) Block valve In this feasibility study, block valves are planned to be installed at major points – starting and end points of the conveyance pipeline, the front and back of the river-, railroad-, or road- crossing points where they are highly likely to cause an accident and deemed difficult to recover in the event of such accident, the front and back of a major device such as flow meter, and a point where drain valves are installed. 25

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia In addition, block valves are commonly installed about every 1 to 3 km in places in need of ongoing maintenance and management. The minimum number of block valves to be installed is estimated at 2, with 1 valve needed for every 2 km. The required number of block valves are estimated as shown in <Table 17>, with the same diameters of the valve and the pipe applied. <Table 17> Required number of block valves Classification Diameter(mm) Distance(m) Required number of valves (estimated) Phase 1 Phase 2 Phase 1 Phase 2 Main line Φ2,000 47,925 36,024 26 20 Φ1,800 - 11,901 - 8 Rangkas Bitung branch line Φ600 - 8,560 - 6 Maja branch line Φ350 - 1,200 - 4 Solear branch Φ1,300 - 4,750 - 5 Parung Panjang branch line Φ600 - 4,800 - 5 (2) Expansion pipe The purpose of installing the expansion joint is to absorb differential settlement in soft ground, to deal with the expansion and contraction of the pipeline by temperature (in terms of exposed piping), and to absorb stress such as natural disasters. The steel pipes buried for water works have a high strength against temperature stress, become a united pipeline connected by welded joints, and have binding force by soil. So, not many expansion joints will be used. Expansion joints are installed in the front and back of block valves, bent pipes, and T-shaped pipes, all of which are vulnerable to temperature stress. The expansion joints are also installed at the terminal connection joints in order to reduce heat stress caused by welding. <Table 18> Required quantity of telescopic pipes Classification Diameter(mm) Distance(m) Required no. of telescopic pipes (estimated) Phase 1 Phase 2 Phase 1 Phase 2 Main line Φ2,000 47,925 36,024 26 20 Φ1,800 - 11,901 - 8 Rangkas Bitung branch line Φ600 - 8,560 - 6 Maja branch line Φ350 - 1,200 - 4 Solear branch line Φ1,350 - 4,750 - 5 Parung Panjang Φ600 - 4,800 - 5 branch line 26

Summary Report In this feasibility study, the required quantity of telescopic pipes is planned to be equal to that of block valves and the telescopic pipes are to be installed along with valves in the valve station. The required quantity of telescopic pipes is shown in <Table 17>. (3) Air valve The air valves are installed at the top of a protrusion on the longitudinal section drawing of the pipeline, where the air is most likely to be gathered. Here, the protrusion is not necessarily the peak point through the entire pipeline, but a local peak near that place. It refers to the top of all the upward protrusion on the longitudinal section drawing of the pipeline. Even if the pipeline is long and there is no protrusion on the longitudinal section drawing, air valves are installed in between block valves so that proper time can be given to refilling and drainage. If the length of the pipeline is long, block valves are installed every 1 to 3km for maintenance. So, air valves must be installed right under the block valve, which is located at the highest location among block valves. Depending on air release and suction per unit time, air valves are classified into rapid air valve, double air valve, and single air valve. Single air valves are generally used for the pipe less than Φ350mm in diameter whereas rapid and double air valves are used for the pipe more than Φ400mm in diameter. The required quantity of air valves is expected to be equal to that of block valves <Table 19> Diameter and required quantity of air valves Conveyance pipeline Air valve Classification Diameter(mm) Distance(m) Diameter Required quantity Phase 1 Phase 2 (estimated) Phase 1 Phase 2 Main line Φ2,000 47,925 36,024 Φ200 26 20 Φ1,800 - 11,901 Φ200 - 8 Rangkas Bitung branch line Φ600 - 8,560 Φ100 - 6 Maja branch line Φ350 - 1,200 Φ80 - 4 Solear branch line Φ1,300 - 4,750 Φ150 - 5 Parung Panjang Φ600 - 4,800 Φ100 - 5 branch line (4) Drain valve The purpose of the drain valve is to discharge sludge or sand remaining on the bottom of the pipe when the pipe is laid, to clean the inside the pipe and remove dead water for maintenance in normal times, and to discharge water within a short time in case of emergency. 27

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia It is advisable to install the drain pipes at a place that drains well, if there is one thereabout, even though the pipeline is not particularly situated in the low place. In a case where there is no suitable waterway in the vicinity, it is desirable to lay the drain pipes to the nearest waterway even if the drain pipeline is extended considerably long. Plus, at least one drain valve must be installed in between block valves. Although it is difficult to tell precisely how many drain valves are needed at this point (in the feasibility study), the required quantity of drain valves is expected to be equal to that of block valves, given that the project area sees little change in ground level and the pipeline is a long distance one. <Table 20> Diameter and required quantity of drain valve Conveyance pipeline Drain valve Classification Diameter Distance(m) Diameter Estimated quantity (mm) Phase 1 Phase 2 (mm) Phase 1 Phase 2 Main line Φ2,000 47,925 36,024 Φ500 26 20 Φ1,800 - 11,901 Φ450 - 8 Rangkas Bitung branch line Φ600 - 8,560 Φ150 - 6 Maja branch line Φ350 - 1,200 Φ100 - 4 Solear branch line Φ1,300 - 4,750 Φ350 - 5 Parung Panjang Φ600 - 4,800 Φ150 - 5 branch line 4.6 Water hammer analysis (1) Water hammer phenomenon and various cases for computational analysis To stop the pump properly, the discharge valve is closed over a certain amount of time so as to prevent against abrupt changes in flow velocity by reducing the discharge amount of the pump. However, if the pump stops when valves are open due to a power outage, the flow rate inside pipes go through dramatic change, leading to sudden surge or drop in pressure. This phenomenon is called water hammer, which may cause damages as described below. • The pump and motor may be counter-rotating due to the backflow of the pressurized flowrate • Increased pressure may cause damages to pumps, valves, flanges, structures, pipelines, and auxiliary facilities • Pipe collapse or rupture occurs if water column separation caused by pressure drop inside the pipe is reunited. • Causes vibration and noise • Abnormal fluctuation in pressure inside pipes makes control devices out of control, making automatic control difficult 28

Summary Report It is difficult to predict if a water hammer phenomenon in the conveyance system is likely to occur. In the past, the simple calculation method using diagrams is used with respect to the simple conveyance system, but now computer analysis driven by a wide range of computer programs makes it easy to predict potential water hammer phenomenon. The computational analysis of water hammer is carried out under the following 16 scenarios, considering a number of cases – in high or low water level at a dam, with or without water hammer protection device, the first or second phase, and Karian-Serpong or Karian-Rangkas Bitung route. 1) Phase 1 (Karian-Serpong Single pipeline) ① Karian-Serpong route without a protection device at H.W.L. (+)67.5 ② Karian-Serpong route with a protection device at H.W.L. (+)67.5 ③ Karian-Serpong route without a protection device at L.W.L. (+)46.0 ④ Karian-Serpong route with a protection device at L.W.L. (+) 46.0 ⑤ Karian- Rangkas Bitung route without a protection device at H.W.L. (+)67.5 ⑥ Karian-Rangkas Bitung route with a protection device at H.W.L. (+)67.5 ⑦ Karian- Rangkas Bitung route without a protection device at L.W.L. (+)46.0 ⑧ Karian-Rangkas Bitung route with a protection device at L.W.L. (+)46.0 2) Phase 2 (Karian-Serpong Dual pipeline single hydraulic system) ① Karian-Serpong route without a protection device at H.W.L. (+)67.5 ② Karian-Serpong route with a protection device at H.W.L. (+)67.5 ③ Karian-Serpong route without a protection device at L.W.L. (+)46.0 ④ Karian-Serpong route with a protection device at L.W.L. (+)46.0 ⑤ Karian- Rangkas Bitung route without a protection device at H.W.L. (+)67.5 ⑥ Karian-Rangkas Bitung route with a protection device at H.W.L. (+)67.5 ⑦ Karian- Rangkas Bitung route without a protection device at L.W.L. (+)46.0 ⑧ Karian-Rangkas Bitung route with a protection device at L.W.L. (+)46.0 (2) Results of computational analysis Among the various computational analysis, the results of the analysis for the Karian-Serpong dual pipeline at 2nd phase and the Karian-Rankas Bitung pipeline at LW.L.(+) 46.0 in Karian dam, are as follows. 29

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia ① Karian-Serpong route without a protection device at low water level of (+)46.0 The result of the computational analysis is shown in <Figure 14>. Ovals in the figure indicate vacuum generating sections, where the lowest pressure line is less than the facility base line ((-)68.65kPa), thereby leading to water column separation in the pipeline. Therefore, it is necessary to install water hammer protection devices. <Figure 14> Water hammer analysis: L.W.L. (+)46.0, no protection device, Karian-Serpong route ② Karian-Serpong route with a protection device at L.W.L. (+) 46.0 The result of the computational analysis is shown in <Figure 15>. If an air chamber with the capacity of 20m3 is installed, there is no place throughout the entire route where the pressure is lower than the facility base line. Facilities and pipelines are operated stably. <Figure 15> Water hammer analysis: L.W.L. (+)46.0, protection device, Karian-Serpong route 30

Summary Report ③ Karian- Rangkas Bitung route without a protection device at L.W.L. (+)46.0 The result of the computational analysis is shown in <Figure 16>. The oval in the figure indicates vacuum generating sections. Throughout the entire route, the lowest pressure line is less than the facility base line ((-)68.65kPa), thereby leading to water column separation in the pipeline. Therefore, it is necessary to install water hammer protection devices. <Figure 16> Water hammer analysis: L.W.L. (+)46.0, no protection device, Karian- Rangkas Bitung route ④ Karian-Rangkas Bitung route with a protection device at L.W.L. (+)46.0 The result of the computational analysis is shown in <Figure 17>. If an air chamber with the capacity of 20m3 is installed, there is no place throughout the entire route where the pressure is lower than the facility base line. Facilities and pipelines are operated stably. <Figure 17> Water hammer analysis: L.W.L. (+)46.0, protection device, Karian-Rangkas Bitung route Computational analyses of water hammer under 16 scenarios revealed that water hammer occurs if there is no protection device, which leads to a conclusion that an air chamber with the capacity of 20m3 is needed to be installed in the Karian-Serpong and Karian-Rangkas Bitung routes, respectively. 31

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 4.7 Welding and joining of steel pipe (1) Method of welding and required quantity of welding Connecting steel pipes in a construction site is essential to maintaining the continuity of the pipeline. Considering that a leakage accident after construction is mostly caused by incomplete connecting parts or joints, it is critical to have precision in welding joints. In this feasibility study, the welding method by diameter, the required number of welding spots, and the weld length are estimated on the assumption that 6m-long steel pipes are used, as shown in <Table 27>. The total weld length including the first and second phase reaches about 1,359,539 dia-inch. (2) Automatic welding An automatic welding is a welding method in which an automatic molding device maintains or molds the roundness of a steel pipe while an external automatic welding device and internal automatic welding robot connect joints of steel pipes automatically. It can be applied to all welded joint methods including butt welded joint and lap welded joint. The automatic molding device fixes both ends of a steel pipe and automatically adjusts or maintains the pipe’s roundness by using a radial-shaped, hydraulic molding cylinder. Then, the external automatic welding device and internal automatic welding robot carry out the actual welding. <Table 21> Method of welding and required quantity of welding Conveyance pipeline Steel pipe joint welding Classification Diameter Distance(m) Required No. Weld length (Dia-inch) Welding (mm) phase1 phase2 phase1 phase2 No. phase1 phase2 method Suction pipe Φ3,200 84 - 14 - 128 1,792 - lap Φ2,200 100 - 17 - 88 1,467 - welding Main line Φ2,000 47,925 36,024 7,988 6,004 Φ1,800 - 1,984 80 639,000 480,320 lap Rangkas Bitung Φ600 - 11,901 1,427 72 - 142,812 welding branch line Φ350 - 8,560 - 200 24 - 34,240 lap Maja branch welding line Φ1,350 792 - 1,200 - 14 - 2,800 bevel Solear branch Φ600 800 butt line welding Parung Panjang - 4,750 - 52 - 41,167 lap branch line - 4,800 - welding Total 24 - 19,200 lap welding 642,259 720,539 32

Summary Report Process analysis shows that the automatic welding method has the process period four times shorter than the manual welding method. On the construction and economic front, the automatic method in Korea is estimated to save about 10 percent of the construction costs compared to the manual method, if pipes with a diameter between 700mm and 3,000mm are constructed on the site. This is extremely helpful to enhance workability as it tends to take enormous time to secure the power supply if the construction conditions are poor. In particular, for the construction of large-diameter steel pipes, the automatic welding method will greatly improve the quality of welding. In Karian-Serpon pipeline route site, it is deemed to be inevitable to introduce automatic welding equipment because the condition of construction site is very poor and it is difficult to hire a large number of skilled welders in local area within short period of time. 4.8 Pipe laying and maintenance road The excavation slope of 1:0.5 is applied in this project, and the sand foundation is planned in order to reduce transverse stress or strain of the pipe. The standard cross-sectional drawing for pipeline installation is shown in <Figure 18>. <Figure 18> Standard cross-sectional drawing for pipeline installation Ideally it is better to utilize the existing roads to maintain and manage the pipeline. However, if there exists no road or if the pipeline passes through a mountainous region or an agricultural land, it is necessary to install a special road dedicated for the maintenance of the pipeline. Generally, the width of a special road is 4m to 5m considering the width of equipment, but it can be adjusted depending on the geographic conditions if it is unavoidable. If a special road for the pipeline is expected to be used as a general road, it is necessary to ask the relevant government department to open a road. If the water service provider has no choice but to open a road, its alignment, structure, and width, etc. need to be determined 33

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia through consultation with the said relevant government. The maintenance management road plan is shown in <Table 22>. <Table 22> Maintenance road plan Planned pipeline Conveyance pipeline Maintenance road Notes Length Diameter Width of land Length Width (km) (mm) acquisition (m) (km) (m) Access road to the booster 0.42 7.0 pumping station Conveyance main line 47.93 D2,000 30 47.93 5.0 Rangkas 8.56 D600 6 8.56 5.0 Bitung Conveyance Solear 4.75 D1,350 13 4.75 5.0 branch line Maja 1.2 D350 4 - - Small Parung 4.8 D600 6 diameter Panjang - - short distance 4.9 Pipe laying for crossing section (1) Field investigation of crossing sections A field investigation of roads-, railroads-, and river-crossing routes for this water conveyance pipeline was carried out from March 15th to 21st, 2018. Based upon a conveyance route map plan obtained from the BBWS C3, an extensive field investigation on the entire route was performed. As for the river- and railroad-crossing points at which the crossing points are clearly identified, each and every point was the subject of this field investigation. In contrast, as for the road crossing routes, this field investigation was performed only on major crossing routes because there exist some crossing points that are not clearly identified or subject to change in the future. The latitude and longitude coordinates of each crossing point are shown as in <Table 23> and the location map of the field investigation is shown as in <Figure 19>. <Table 23> Coordinates of crossing points No Classification Crossing point Latitude Longitude 1 Rivercrossing 01 river 6° 24′18.68ʺS 106° 20′47.73ʺE 2 Rivercrossing 02 river 6° 20′39.12ʺS 106° 24′34.85ʺE 3 Railroadcrossing 01 railroad 6° 19′45.36ʺS 106° 25′58.48ʺE 4 Roadcrossing 01 road 6° 20′17.65ʺS 106° 34′28.60ʺE 5 Railroadcrossing 02 railroad 6° 20′13.84ʺS 106° 35′46.81ʺE 6 Roadcrossing 02 road 6° 20′26.44ʺS 106° 38′13.06ʺE 7 Rivercrossing 03 river 6° 19′35.28ʺS 106° 39′33.79ʺE 34

Summary Report <Figure 19> Location map of field investigation (2) Railroad- and road-crossing sections There are two railroad crossing sections which pipelines need to traverse. The Tigaraka Station requires a crossing width of 40m. The crossing point, which is 3km away from Parung Panjang Station heading for Cicayur Station, requires a crossing width of 15m. The Jacking method will be applied to these two railroad-crossing points, and the detailed information about the railroad crossing installation is shown in <Table 24>. <Table 24> pipe installation for railroad-crossing sections Classification Measuring point Distance(m) Diameter(mm) Remarks Railroad No.17+135~No.17+195 60 2,000 Actual railroad crossing crossing No.38+693~No.38+728 35 2,000 width: 40m Actual crossing width: 15m There are five road crossing points. Whether they would be installed by the open cut method or jacking method needs to be reviewed thoroughly when developing a working design. The current state of the road crossing points is shown as in <Table 25>. 35

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 25> pipe installation for road-crossing sections Classification Measuring point Distance(m) Diameter(mm) Remarks Road No.11+956~No.11+968 12 2,000 Obtained data crossing No.36+132~No.36+143 11 2,000 Field Investigation No.43+574~No.43+585 11 2,000 Field Investigation No.43+900~No.43+908 8 2,000 No.44+235~No.44+245 10 2,000 Obtained data Obtained data (3) Pipe installation for river-crossing sections River crossing sections in the project area include the Ciuyah River, the Cidurian River and the Cisadane River. The crossing point of the Ciuyah River has the width of 40m, the slope height of 20m, and the water depth of 0.5m with its bed being the rock ground. The crossing point of the Cidurian River has the width of 20m, the slope height of 10m, and the water depth of 2.5m. <Table 26> shows the list of the river-crossing points where crossing pipe installation is needed. <Table 26> river crossing pipe installation Classification Measuring point Length Diameter River (m) (mm) No.0+543~No.0+583 40 2,000 Ciuyah River River crossing No.13+439~No.13+459 20 2,000 Cidurian River No.47+004~No.47+074 70 2,000 Cisadane River Ciuiyah river is shallow with a low flow rate and Cidurian river is narrow with the water depth of 2 to 3m. So, the coffer dam + open cut technique is deemed appropriate for these two rivers. On the other hand, the coffer dam + sheet pile technique is deemed better for Cisadane river, which is wide and has a high flow rate. A more comprehensive examination on the river flow quantity and depth needs to be conducted in the stage of the detailed design period to review the comprehensive review. 36

Summary Report 4.10 Corrosion protection of steel pipe (1) Anti-corrosion painting Steel pipes used for conveyance pipelines have metal properties. That is, they are subject to corrosion, chemical or electrochemical oxidation of metal in soil environment. The steel pipe’s outer surface which contacts the soil is coated with polyethylene in order to protect the steel pipe against natural corrosion. At the same time, its inner surface which contacts raw water for drinking water is lined with epoxy resin paint. In general, a steel pipe is required to have a service life of more than 50 years, so the painting of a steel pipe needs to have a strong adhesiveness, wear resistance, and hydrophobicity, a physical property of a material that is not attracted to water. The painting materials used for coating the inner surface of a steel pipe that contacts drinking water must not produce any hazardous substances. Coating methods used to paint the inner surface of a steel pipe include the fusion bonded epoxy coating and liquid spray coating using nanocomposite resin epoxy, ceramic epoxy, or polyurea resin. A specific coating method will be determined when developing a working design. In painting the outer surface of a steel pipe, not only the quality of the painting materials is important, but it is also important to apply a reliably painting method. Until 1993, asphalt enamel and coal tar enamel were used as the painting material In Korea. However, they are now discarded in Korean Industrial Standards and no longer used in advanced countries due to the following reasons. ① Asphalt or coal tar enamel coated steel pipes are easily damaged during transportation and attachment. ② Due to low temperatures in winter, cracks or pinholes are created, and even a minor shock causes damage. ③ Low adhesiveness to a steel pipe makes the pipe less durable. In Korea, its service life is 20 years. ④ Coal tar enamel is a hazardous substance listed in Material Safety Data Sheet (MSDS). The surface coated with this substance causes soil contamination. (3) Applicability of Indonesian steel pipe According to our investigation, Gunung Steel does not only have a PE coating machine to paint the outer surface of a steel pipe, but it is also not equipped with a fusion bonded epoxy coating machine, and currently coating the inner surface with a spray gun using compressed air. Furthermore, the company has no special place dedicated to painting work and poor production conditions where gases for welding are not removed. It is natural to say that it is not certain to secure high quality coating under given conditions. On the other hand, KHI Pipe Industries has a PE coating machine to paint the outer surface 37

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia of a steel pipe. But with regard to the steel pipe with a diameter larger than 1,200mm, it is using a manual coating method either with liquid PE or asphalt enamel. To paint the inner surface of a steel pipe, it is also using a low-temperature liquid epoxy painting method instead of the fusion bonded epoxy coating. According to our investigation, local steel pipe makers are capable of producing straight pipes but not capable of applying the fusion bonded epoxy coating method for coating the inner surface. Besides, the PE coating method cannot be applied for the large pipe (with a diameter greater than 1,200mm). It will difficult for local producers to invest in additional PE coating machine for the large pipe, secure skilled technicians, and assure quality in a short period of time. Therefore, it seems reasonable that we source steel pipes less than 1,200mm in diameter from Indonesian companies and steel pipes larger than 1,200mm from Korea. (4) Cathodic protection Painting is a method commonly used to fight corrosion in steel pipes especially in an environment such as water and soil, where there is the electrolyte. Nevertheless, painting itself cannot provide 100 percent protection against corrosion. But both painting and cathodic protection methods are applied together, it is possible to obtain a complete immunity from corrosion. In this feasibility study, the best protection method will be determined in the stage of the working design after a thorough physical inspection on the effect of protection methods, the size of leakage current, any external power supply, and possible inflow of another current. Impressed current cathodic protection is applied to the area where external electric power can be received from nearby area and sacrificial anode cathodic protection is applied to the outside area where it is difficult to receive external electric power. <Figure 20> Conceptual drawing of impressed current cathodic protection 38

Summary Report <Figure 21> Conceptual diagram of sacrificial anode cathodic protection 4.11 Quality assurance of pipeline (1) Nondestructive test and required number of test objects Nondestructive testing is a wide range of inspecting techniques used to examine a material or article by using physical energy without altering or causing damage to the material or article being inspected. In connection to steel pipe, the nondestructive testing is mainly applied to inspect any defect in welded joints. In this feasibility study, approximately 5 percent of the welded joints in the project area are to be subject to nondestructive testing for the purpose of assuring quality of the welding joints. The estimated number of the test objects is shown as in <Table 27>. The total length of weld under the nondestructive test is estimated at 67,977dia-inch. <Table 27> Required number of NDT object Conveyance pipeline Steel pipe joint welding NDT Classification Dia. Distance(m) No. of Welding length No. of test Test length (mm) phase1 phase2 points (Dia-inch) welding points (Dia-inch) Phase1 Phase2 phase1 phase2 Phase1 Phase2 Phase1 Phase2 Suction Φ3,200 84 - 14 - 1,792 - 1 - 90 - pipe Φ2,200 100 - 17 - 1,467 - 1 - 73 - Φ2,000 47,925 36,024 7,988 6,004 639,000 480,320 399 300 31,950 20,416 Main line Φ1,800 - 1,984 142,812 - 99 - 7,141 - 11,901 - 71 - 1,712 Rangkas - Bitung Φ600 - 8,560 - 1,427 - 34,240 10 - 140 branch line - 40 - 2,058 Maja Φ350 - 1,200 - 200 - 2,800 branch line 792 - 41,167 - 40 - 960 Solear Φ1,350 - 4,750 - 32,113 36,027 branch line - Parung Φ600 - 4,800 - 800 - 19,200 Panjang 642,259 720,539 branch line Total 39

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia Under the technical standards for nondestructive testing such as American Society of Mechanical Engineers (ASME) and those in advanced countries, at least five (5) percent of the welded joints are subject to nondestructive testing. About the welding spot which are not passed in non-destructive test, non-destructive test shall be carried out on the double numbers of welding spots after re-welding. As for the welded joints where nondestructive tests are not performed, hydraulic tests or water/air tightness tests need to be conducted. (2) Hydraulic pressure test The welding spots which are not checked by nondestructive testing, shall be inspected the quality by hydraulic pressure test. Before injecting water into the pipeline for the hydraulic pressure test, the pipeline needs to be backfilled so that it does not move during the test. In the hydraulic pressure test, it is also important to take time to fill the pipeline with water so as not to destroy the pipeline by a drastic pressurization. Inject water slowly into the pipeline and remove the air inside the pipe. While filling water into the pipeline, keep checking if the air valve works properly to remove air or if the pipeline has any problem. Seek appropriate countermeasures if leakage occurs. It is highly advisable that the hydraulic pressure test is conducted one or two days after the water filling of the pipeline. Test pressure, duration, and allowable pressure drop will be determined by considering various factors including working pressure, pipe type, joint structure, pipeline extension, auxiliary facilities, and construction conditions. <Figure 22> Conceptual drawing of hydraulic pressure test (3) Commissioning test (water flow test) This conveyance system needs to take raw water from the Karian dam, or a water intake source, and provide a stable supply of raw water to the Serpong and other four water treatment plants. Therefore, it is imperative that we conduct a commissioning test against the entire route of the conveyance system, upon the completion of construction, to see if the system is capable of supplying the required amount of water without leakage or contamination. 40

Summary Report 4.12 Building plan of the booster pumping station The booster pump station shall have sufficient space for the installation of the planned pump and electrical equipment including both phase 1 and phase 2. It shall be also ensured for the sufficient space and moving lines to inspect and repair the equipment, and the sufficient floor- height and entry/exit for equipment carry-in/out shall be secured. The layout plan established according to the above considerations is shown in <Figure 23> below. <Figure 23> Building layout plan The site area will be calculated more accurately in the stage of the working design. The estimated site area is compared with that of the 2015 report, as shown in <Table 36>. From the layout considering the facilities for phase 2 within the overall site area, it can be seen from the <Table 28> that the required structure area on this feasibility study is more than double of that on PPP report. <Table 28> Comparison of building area Classification This plan (m2) 2015 report (m2) Building 5,409 2,030 Roads on the premises 1,843 1,998 Green area 1,088 2,423 Slope and others 6,112 6,332 Parking lot - 1,074 Sum 14,452 13,857 41

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia Although the site area is similar as planned area on PPP report, building area is almost twice as large as that on PPP report, because the installation space of the pumps and electric equipment are absolutely insufficient. Pumps room are located on the 1st floor and 1st basement floor, and electric room, operation room and office are arranged on the mezzanine floor and 2nd floor. <Table 29> shows the comparison between the previous pumping station plan on PPP report and this feasibility study. <Table 29> Building scheme of booster pumping station 2015 report This plan Site area 14,383 m2 14,383 m2 Size 1 basement/3 stories high 1 basement/3 stories high Structure Reinforced concrete structure Reinforced concrete structure Building 1,419.32 m2 3,418.16 m2 area area(m2) main room area(m2) main room 1B 1,179.90 pump station 1B 5,343.16 pump station 1,419.32 1F 3,418.16 1F 342.00 pumpstation,dynamo- MF 1,010.32 pumpstation,dynamo- Floor area 839.67 room, lobby,warehouse 2F 812.42 room,lobby,warehouse 342.00 3F 106.20 electricalroom,lobby, (m2) MF electricalroom,lobby, 2F upperpumpstation upperpumpstation operationcenter,office, operationcenter,office, 3F lobby,TM/TCroom lobby,TM/TCroom watertankroom,stairhall watertankroom,stairhall Total 4,122.89 Total 10,690.26 4.13 Electric power lead-in and emergency generator (1) Electric power lead-in We wrote an official document after paying a visit to Indonesia’s SDA. Then we sent the document to the headquarters and the local office (Banten province) of the PNL to discuss ways to supply power. 42

Summary Report ① Current state of substations with incoming power In the vicinity are Rangkas Substation and Rangkas New Substation, which can supply power to the booster pumping station. ② Commercial power supply <Figure 24> Substation capable of power supply The commercial power supply will be supplied from Rangkas New Substation by installing an additional 20kV-distribution line. The substation is about 10km away from the booster pumping station. The construction cost is estimated about 480 million KRW and it shall be paid to the PNL, which is in charge of implementing the construction. The site area 12m x 6m to install the switchgear in booster pumping station shall be provided PLN. The power lead- in system is shown in <Figure 24>. ③ Standby power source Although Rangkas substation is about 10km away from the booster pumping station, the substation will be used as a standby power source in case of emergency. If power is supplied from one substation, the regular charge is applied. The premium charge is applied if two substation supply power. Premium charge is six times higher than regular charge, which means higher maintenance cost. This time, power is to be supplied from one substation and whether to have power supplied from two substations will be reviewed in the next stage of design. ④ Standard voltage and capacity The standard frequency used in Indonesia is 50hz and its rated voltage is shown as in <Table 30>. 43

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 30> Rated voltage in Indonesia Classification Voltage Amount of power used Remarks High Voltage, HV 150kV more than 30MVA Booster pumping Medium Voltage, MV 25kV, 30kV, 70kV 500kVA ∼30MVA station less than 500kVA Low Voltage, LV 220/380V Flowmeter station ⑤ Power lead-in plan To supply power to the booster pumping station, 20kV will be supplied from the switchgear installed on the premises by the PNL. The main transformer is to depressurize it to 6.6kV and then the secondary transformer is to depressurize 6.6kV to 400V/230V. To supply power to the flowmeter station, 230V will be supplied from the electric pole installed by the PNL in the vicinity of the site. (2) Emergency electric generator The booster pump needs to be in continuous operation in case of a commercial power outage. Therefore, a number of requirements for the facility to be operated more than 50 percent of its capacity are factored in. <Table 31> Capacity and number of emergency electric generator Phase Voltage and frequency Generator load Notes No. Power (kW) Total Phase 1 6.6kV, 50Hz 3 1,360 4,080 Emergency operation Phase 2 6.6kV, 50Hz 3 1,000 3,000 Emergency operation Total 7,080 4.14 Integrated monitoring and control system The integrated control room, which will be located in the booster pumping station, is basically designed to control the operation of pumps by receiving values indicated on the flowmeter installed in the main and branch pipelines of the conveyance system. Such values are regulated by the water intake valve (work scope of a PPP project provider) depending on the raw water demand of each water treatment plant. In order to adjust the conveyance amount when raw water becomes scarce during drought season, the control room will also receive water level values measured on the level meter of the intake tower. However, the total conveyance amount is controlled in the conveyance system by the method that regulates the operation of pumps. The flow of water treatment plants will not be 44

Summary Report controlled in the conveyance system since the conveyance pipelines are distant from the control room, which makes a daily inspection difficult. All valves are planned as a manual type since the power lead-in is not easy even if motor operated valves are installed. Still, each water treatment plant can control the inflow rate if intake valves (work scope of a WTP PPP project provider) in the receiving well are a motor operated type. The installation location of measuring instruments and operation control is shown in <Figure 25>. <Figure 25> Installation location of measuring instruments and operation control Control equipment for automation and remote operation consists of monitoring equipment that sends all measured values and operation or failure status of the pump to the operator, data transmission device, data recording and storage device, and control equipment that either automatically or manually controls operation. Given that the control room is distant from flowmeters scattered across conveyance pipelines and intake tower, a wireless communication network through which values measured by flowmeters are transmitted to the control room is planned. Flowmeters are used to measure the amount of raw water used by each water treatment plant. Their measured values are used to identify the water flow rate and to decide charges for raw water used by a water treatment plant. Accordingly, flowmeters are required to maintain a high level of precision. The required quantity of flowmeters is shown in <Table 32>. 45

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 32> Required quantity of flowmeter Classification Diameter of Required Nos. of Remarks conveyance pipe flowmeter (mm) Phase 1 Phase 2 Inlet of booster pumping station Φ2,200 1 1 Ultra-sonic Outlet of booster pumping station Φ2,000 1 - Ultra-sonic Φ1,800 - 1 Ultra-sonic Inlet of Serpong WTP Φ2,000 1 - Ultra-sonic Φ1,800 - 1 Ultra-sonic Rangkas Bitung branch line branch point Φ600 - 1 Ultra-sonic Maja branch line branch point Φ350 - 1 Ultra-sonic Solear branch line branch point Φ1,300 - 1 Ultra-sonic Parung Panjang branch line branch point Φ600 - 1 Ultra-sonic 5.0 Project cost estimation 5.1 Composition of project cost The total project cost is made up of direct cost including construction cost, commissioning and training cost, and consulting service fees and indirect cost including physical and price contingency, project management cost, and loan service charges. The construction cost is calculated based on an estimated quantity of conveyance system facilities. A part of the construction cost may increase or decrease depending on the results of more detailed investigations on geology, which will be conducted when developing a working design. The construction cost is also subject to change depending on cost estimation criteria or terms and conditions agreed upon by suppliers of steel pipes or pumps. Considering all possible changes in costs, contingency funds are allocated to prepare against inflation or quantity increase. The composition of the total project cost is shown as in <Figure 26>. 46

Summary Report <Figure 26> Composition of total project cost <GOI> <EDPF> Project Direct cost Direct construction cost cost Commissioning and training cost Consulting fee Indirect cost Contingency Service charge Project management (TBD) cost Land acquisition and compensation cost Taxes and duties 5.2 Project cost The total project cost for the first phase, including all the calculated costs for direct construction, commissioning, working design/bidding preparation, construction supervision, and indirect expenses, is shown in <Table 33>. 5.3 Project implementation period Given the project scale, it is expected to take at least four years to implement the first phase project. If the first and second phases are implemented together, it is estimated to take no less than 6 years. In order to construct and operate the Serpong water treatment plant designed to provide a stable supply of clean and safe water once the Karian dam begins to be filled with water, it is inevitably urgent to construct the conveyance system. To expedite the project implementation, it would be better to work on working design immediately after the loan agreement is signed. To this end, it is advisable to select consultants during the course of negotiation for the loan agreement, which will contribute to an efficient implementation of the project. 47

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 33> Total project cost (phase 1) Unit: thousand IDR (converted into USD) Classification Foreign EDPF Total Recipient Total currency Local country currency GOI1) 1. Construction cost 1,957,623,815 777,246,953 2,734,870,770 2,734,870,770 (145,009,171) (57,573,848) (202,583,020) (202,583,020) a. Temporary work - 21,591,509 21,591,509 21,591,509 (-) (1,599,371) (1,599,371) (1,599,371) b. Booster pumping 153,089,757 219,009,137 372,098,898 372,098,898 station (11,339,982) (16,222,899) (27,562,881) (27,562,881) c. Main conveyance 1,804,534,054 536,646,307 2,341,180,360 2,341,180,360 pipeline (133,669,189) (39,751,578) (173,420,767) (173,420,767) 2. Commissioning 4,777,772 9,146,939 13,924,710 13,924,710 (353,909) (677,551) (1,031,460) (1,031,460) 3.Consulting fee 157,179,150 45,065,325 202,244,475 202,244,072 (11,642,900) (3,338,172) (14,981,072) (14,981,072) a.Design/bidding 77,215,140 17,302,302 94,517,442 94,517,442 preparation (5,719,640) (1,281,652) (7,001,292) (7,001,292) b. Construction 79,964,010 27,763,024 107,727,034 107,727,034 supervision (5,923,260) (2,056,520) (7,979,780) (7,979,780) 4. Total direct cost 2,119,580,736 831,459,216 2,951,039,952 2,951,039,952 (1+2+3) (157,005,980) (61,589,572) (218,595,552) (218,595,552) 5. Contingency 150,267,763 88,978,608 239,246,271 239,246,271 (11,130,938) (6,591,008) (17,721,946) (17,721,946) a. Physical contingency 105,979,037 41,572,967 147,552,003 147,552,003 (5% of 4) (7,850,299) (3,079,479) (10,929,778) (10,929,778) b. Price contingency 44,288,627 47,405,642 91,694,268 91,694,268 (3,280,639) (3,511,529) (6,792,168) (6,792,168) 6. Taxes and duties - 824,999,175 824,999,175 (-) (61,111,050) (61,111,050) a. VAT for L.C(10%) - 83,145,920 83,145,920 (-) (6,158,957) (6,158,957) b. VAT for F.C(10%) - 211,958,073 211,958,073 (-) (15,700,598) (15,700,598) c. Import duties (25%) - 529,895,183 529,895,183 (-) (39,251,495) (39,251,495) 7. Project management - 59,020,826 59,020,826 cost (2% of 4) (-) (4,371,913) (4,371,913) 8. Land acquisition cost - 278,817,805 278,817,805 (-) (20,653,171) (20,653,171) 9. Loan service charge (TBD) 10. Total project cost 2,269,848,399 920,437,814 3,190,286,223 1,162,837,805 4,353,124,028 (4+5+6+7+8+9) (168,136,918) (68,180,580) (236,317,498) (86,136,134) (322,453632) Note 1) GOI: Government of Indonesia Applied exchange rate 1 USD = 13,500 IDR, 1 USD = 1,080 KRW, 1 KRW = 12.5 IDR 48

Summary Report As for the first phase, it is expected to take 12 months to develop a working design, including supporting activities for bidding application and selection of a constructor. It is expected to take 36 months for construction including commissioning test. So, the total project implementation period is planned to be 48 months. But the selection of consultants needs to be finished by the first year of project implementation before beginning design works. <Figure 27> shows the project schedule for the first phase, with consideration for the construction period of the Karian dam and the Serpong water treatment plant. The year in parentheses means an expected year of completion when the construction schedule of the Karian dam (to be completed by the end of 2019) is taken into account. <Figure 27> Project implementation schedule (Phase 1) Before- Year 1 Year 2 Year 3 Year 4 hand Classification -6 -3 3 6 9 12 3 6 9 12 3 6 9 12 3 6 9 12 3 Construction for Karian dam 1. Selection of consultants 2. Working design 3. Selection of constructors 4. Construction EDPF 1) Booster PS 2) Main CS KSCS 5. Commissioning and training 6. Construction supervision 1. AMDAL approval 2. LARAP submission 3. LARAP GOI negotiation 4. LARAP compensation 5. Permission consultation 6. Permission Construction for Serpong WTP 49

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 5.4 Financing plan The project cost for the first phase is estimated at 4,353,124 million IDR (322,453,632USD). Of which, 3,190,286 million IDR (236,317,498USD) comes from EDPF and 1,162,837 million IDR (86,136,134USD) comes from the Indonesian government. The financing plan for the first phase is shown as in <Table 34>. <Table 34> Financing plan (phase 1) Unit: thousand IDR (converted into USD) EDPF Recipient GOI Item Currency Foreign Local currency Subtotal Total Amount currency 1,162,837 million 3,190,286 4,353,124 IDR 2,269,848 920,438 (USD) (168,136,919) (68,180,580) (236,317,498) (86,136,134) (322,453,632) Composition EDPF 71.15% 28.85% 100% Total 52.14% 21.14% 73.29% 26.71% 100% Note) Applied exchange rate 1 USD = 13,500 IDR, 1 USD = 1,080 KRW, 1 KRW = 12.5 IDR It is expected to take a total of 51 months to implement the first phase project, which includes 15 months for working design/bidding preparation and 36 months for construction and commissioning. In the fifth year, water flowing test and comprehensive commission only will be conducted for three months. The annual financing plan is shown as in <Table 35>. <Table 35> Annual financing plan (phase 1) Unit: thousand IDR (converted into USD) Item Unit Total Year 1 Year 2 Year 3 Year 4 Year 5 Million IDR 3,190,286 96,654 943,065 1,206,675 921,780 22,110 EDPF (USD) (236,317,498) (7,159,594) (69,856,667) (89,383,352) (62,280,069) (1,637,815) GOI Composition 100% 3.03% 29.56% 37.82% 28.89% 0.69% (%) 306,399 258,385 337,521 256,021 4,551 Million IDR 1,162,837 (22,696,229) (19,139,628) (25,001,569) (18,964,535) (334,174) (USD) (86,136,134) 26.35% 22.22% 29.03% 22.02% 0.39% 403,053 1,201,450 1,544,196 1,177,802 26,622 Composition 100% (%) Million IDR 4,353,124 Total (USD) (322,453,632) (29,855,823) (88,996,295) (114,384,921) (87,244,604) (1,971,989) Composition 100% 9.26% 27.60% 35.47% 27.06% 0.61% (%) Note) Applied exchange rate 1 USD = 13,500 IDR, 1 USD = 1,080 KRW, 1 KRW = 12.5 IDR 50

Summary Report 5.5 Separation of foreign and local currency In this project, some materials and labor will be sourced from Indonesia. There may be other equipment/materials or consulting service which need to be sourced from Korea if they fail to meet the quality levels required by the Indonesian project execution agency. In this regard, cost items are separately denominated in foreign and local currency as shown in <Table 36>. <Table 36> Items in foreign and local currency for project cost estimation Classification Foreign currency (Korea) Local currency (Indonesia) Remarks ∙ Machine equipment ∙ temporary work - Booster pump ∙ reinforcing bar, concrete - Valves (block valve, check valve, ∙ aggregate (sand, pebble), cement, Booster etc.) etc. pumping - Water hammer protection device ∙ mold, floor post, scaffolding, etc. station ∙ architectural materials ∙ Electrical, instrumentation and ∙ paving materials (asphalt) control equipment ∙ construction work classification - Integrated operation and - civil, basic, structure work monitoring control system - pipe installation and connection - image surveillance and control - paving, subsidiary work device - landscaping, fencing - CCTV equipment - metering instruments ∙ Pipe materials (steel pipes more ∙ Pipe materials (steel pipe less than than 1,200mm in diameter) 1,200mm in diameter) ∙ Valves (block valve, air valve, ∙ Reinforcing bar, concrete, Conveyance drain valve) aggregate pipeline ∙ corrosion prevention ∙ paving materials (asphalt) ∙ metering instruments (flowmeter) ∙ Construction work classification ∙ welding - Civil, basic, structure work ∙ nondestructive test of weld zone - Pipe construction - Packing, subsidiary work Others ∙ Design and supervision cost ∙ Design and supervision cost ∙ Physical and price contingency ∙ Physical and price contingency cost cost ∙ Loan service charge ∙ Taxes and duties ∙ Commissioning and training cost ∙ Land acquisition and resettlement compensation ∙ Project management cost ∙ Commissioning and training cost 51

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia Cost items (phase 1) in foreign and local currency from the direct construction cost estimated based on the above criteria are shown in <Table 37>. <Table 37> Direct construction cost items in foreign and local currency (phase 1) Unit: million IDR (converted into USD) Items Total Foreign currency Local currency Construction cost (Korea) (Indonesia) 1. Temporary work 2,734,870 1,957,623 777,247 2. Booster pumping station (202,583,020) (145,009,171) (57,573,848) 2.1 Civil works 21,592 - 21,592 2.2 Architectural works (-) 2.3 Mechanical works (1,599,371) 153,090 (1,599,371) 2.4 Electricity/measurement works 372,099 (11,339,982) 219,009 3. Main conveyance pipeline - 3.1 Materials (steel pipe) (27,562,881) (-) (16,222,899) 3.2 Civil works 90,824 - 90,824 3.3 Electricity/measurement works (-) (6,727,682) 84,999 (6,727,682) 79,704 (6,296,210) 79,704 68,091 (5,904,004) (5,043,772) (5,904,004) 88,860 1,804,534 3,861 (6,582,210) (133,669,189) (286,000) 112,711 1,490,403 44,620 (8,348,984) (110,400,285) (3,305,212) 2,341,180 308,885 536,646 (173,420,767) (22,880,378) (39,751,578) 1,556,194 5,245 65,790 (115,273,652) (388,526) (4,873,366) 777,693 468,808 (57,606,879) (34,726,501) 7,293 2,048 (540,237) (151,711) 6.0 Project execution agency and implementation system 6.1 Project execution agency Indonesia’s Ministry of Public Works and Housing, which is called PU for short, is a project execution agency of this project. Under the PU, there is a department called Directorate General of Water Resources, or SDA, which is in charge of water resource development and management in the country. There is also a department called Directorate General of Human Settlements tasked with water supply and water works management. In this project, SDA takes charge of the construction of the Karian dam and conveyance system whereas DGHS takes charge of the construction of water treatment plants and transmission pipelines. Under the SDA is an affiliated agency called the Ground Water and Raw Water Center, or PUSATAB, specifically in charge of this project for the construction of the conveyance 52

Summary Report system. The PUSATAB coordinates and facilitates communication among the parties interested in the development of the groundwater and raw water, takes care of quality management, promotes and manages programs, and supervises compliance with regulations, standards, and procedures for technical assistance with regard to the supply of raw water and use of groundwater. For reference, there is a water supply division tasked with water supply affairs under the SDA. The division is in charge of making policies and regulations related to water supply system as well as monitoring and supervision. Besides the PUSATAB, which takes charge of policy planning and making under the Ministry of Public Works and housing (PU), there are a number of provincial organizations called Balai taking care of actual execution and operation. In connection with the construction of the Karian dam and conveyance system, there is BBWS C3 (Balai Besar Wilayah Sungai Cidanau, Ciujung, Cidurian), a provincial agency corresponding to the central PUSATAB. The BBWS C3, located in Banten province and Serang city, oversees three rivers – Cidanau, Ciujung, and Cidurian – in the region and is primarily in charge of planning, building, operating, maintaining, repairing, and flooding prevention of all water resource-related facilities (including river, beach, dam, lake, pond, and so on.) 6.2 Project implementation capability The project execution agency (PEA) is now performing tasks similar to those of this project (Karian – Serpong Conveyance system). Main jobs that the PUSATAB needs to do for the successful implementation of this project include coordination with related institutions in Indonesia, loan agreement with Korea Eximbank/performance report, employment of consultants for design/supervision, bidding process to select a contractor for construction and material and payment management. The PUSATAB has a planning and administration department (planning subdivision and technical subdivision), which is capable of performing the aforementioned tasks. The BBWS C3 also has an organization for planning, implementation, and administration/management. The two organizations are deemed to have enough capability to implement and manage this project. Given that this project is closely connected to the construction of the Karian dam, intake tower, and conveyance tunnel, it is fair to say that the BBWS C3, which is now taking charge of management and supervision of the construction site, should manage and supervise the site. Selecting the very able consultants for design/supervision is critical to the overall quality of the project, therefore, it is natural that the PUSATAB should directly conduct the selection process. 53

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 6.3 Necessity of working design There exists a 2006 report on the feasibility study and basic design of the Karian – Serpong conveyance system route conducted by the Korea Rural Community Corporation (KRC) under the Korea International Cooperation Agency (KOICA) fund. But the report needs to be enhanced to be used as a report for construction or bidding guidelines as it has many design errors, poor documents, and outdated information. ① Raw water allocation for the second phase was not considered There needs an additional raw water allocation plan upon completion of the Pasir Kopo dam. In other words, if the raw water allocation for the second phase is not considered, a completely new system will have to be installed after the Pasir Kopo dam is completed, which makes the operation of the system complicated and difficult to control. ② A single hydraulic system is needed for operation/maintenance In the existing design concept, a separated two hydraulic system is planned, one for the high head pump and the other for the low head pump. This means the entire conveyance system needs to stop in case of an emergency such as leakage accident occurring in either of the two pipelines. It also makes it difficult for the system to cut off the water supply for a regular checkup of the pipeline. Therefore, in this feasibility study, two pipelines are installed and connected together so that the operator can do the repair work in case of an emergency or check the system without cutting off the water supply. Considering that a stable water supply is directly related to the quality of people’s life, avoiding the cutoff is an important matter. ③ Selection of the booster pump The booster pump plays a key role in the conveyance system; therefore, its types and specifications need to be specified in an enhanced design drawing. In addition, it does not only lack the basic design of the pump but also protection measures against water hammer phenomenon which may occur in case of a power outage. Plans for a combined operation, compatibility, and operation depending on the water level at a dam were also left out. Such a poorly developed design of the pump facility could cause damage to the whole system at a time. ④ Building plan of the booster pumping station Considering the final phase of this project, it is necessary to secure enough installation space for pumps in building the booster pumping station. Unfortunately, the specifications and the number of pumps to be installed in the final phase were not factored in the existing architectural design, so there is not enough space for pumps to be installed. It is worth noticing that all facilities including pump facilities, power/control equipment, and water 54

Summary Report hammer protection devices operate together in a combined manner within the same room, instead of operating independently. Just developing an extra pumping station later cannot be the solution. Therefore, a new building design that allows the entire pump system to be installed in the single room needs to be developed. ⑤ Hydraulic stability of the conveyance system Among many hydraulic phenomena, water hammer is undoubtedly the most dangerous event that we encounter in operating the pipeline. Water hammer brings about grave damage to the conveyance system due to the excessive pressure caused by the abrupt stop of the pump. Damages include broken pumps or valves, crushed pipes, or water column separation due to negative pressure. However, no protection devices are planned against water hammer in the existing design drawing. ⑥ Power lead-in In order for the booster pumping station to properly function, a high capacity, high voltage power needs to be supplied stably. This requires a close cooperation and consultation with the PLN according to the state of power demand and supply and related regulations. If construction begins without an appropriate power plan and the facility fails to secure incoming power on account of local power supply situation, there will be no way of operating the booster pumping station. With a close coordination with the PLN, a new and feasible detailed design should be developed. ⑦ Quality assurance of the conveyance pipeline Water supply facilities are closely related to the quality of people’s lives in the service area. Once the water supply system is introduced, there should be no suspension of operation. Even if a leakage accident occurs, the system needs to be repaired and normalized without cutting off the water supply. It is required for the design life of the conveyance pipeline to be 50 years and longer, but in reality, there is no way of checking the quality of the pipeline except for the construction stage because the pipelines are buried underground. In other words, it is impossible to check the quality of pipelines after installation. Hence, it is necessary to design nondestructive tests to test the quality and thickness of the steel pipe, coating for anti-corrosion, weld zone of the joints, in addition to the cathodic protection method. All of these were not planned in the previous design drawing. ⑧ Valves for operation and maintenance The booster pumps need to be operated according to change in demand in the water treatment plant and water levels of the Karian dam. Theoretically, pumps respond to changing 55

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia demand depending on the opening rate of the inlet valve controlled by each water treatment plant. However, in the existing design, valves in the pipeline were electrically installed to control the flow rate. Since it does not directly respond to water demand, it could cause confusion in allocating raw water. The idea of using valves to control the operation of the pump in the existing design was not appropriate, so it is required to rectify the design concept. ⑨ Design drawing A design drawing should be made in detail enough to be put into construction. The existing design drawing does not only have the aforementioned errors but lacks detailed description. It would be much better if we create a new design drawing in accordance with a revised plan than compensating the existing drawing. ⑩ Specifications Specifications are an integral part of the contract. Being attached to the contract, specifications specify all technical requirements by the ordering organization, which are not described in the contract; construction site standards and procedures affecting the overall performance of the conveyance system including quality standards for materials and construction, and joint welding of steel pipes; nondestructive tests and other test technique to check the quality of weld zone; and acceptance criteria. Without specifications, there is no evidence that guarantees the quality of the construction project. Specifications were not found in the existing design. ⑪ Bill of Quantities (BOQ) The bill of quantities is a detailed list of the materials and manpower required for each work classification in the construction. It should be written in the working design stage so that it can make the basic foundation for the calculation of the construction cost. In a bid, a BOQ without quotation is given to a bid applicant, who then fill out and submit the document. Therefore, a BOQ is a basic document that we go upon to compute the completed amount in the construction stage; to change a design, and to calculate the completion of construction. The BOQ was not found in the existing design. As described above, the existing design has many errors and omissions and fails to specify quality standards, which is deemed almost impossible to be used for bidding or construction. Therefore, it is an inevitable conclusion that we draw a new working design in order to stabilize the overall hydraulic and establish quality standards for each process. 56

Summary Report 6.4 Necessity of employment of International consultants In general, EDPF funded cooperation projects require complicated management methods. Particularly in this project, large-scale booster pumping facilities and large-diameter conveyance pipelines require highly complex engineering techniques. Therefore, having the very competent consultants is essential to the effective execution of the fund as well as the efficient preparation, design, construction, and operation of the project. To assure performance and quality of the accomplishment, project execution agencies (PUSATAB and BBWS C3) need to implement this project in accordance with the terms and procedures agreed with the Export-Import Bank of Korea and, on key issues, receive an approval from the Bank. These works require a high level of expertise and experience that meet the requirements by the Bank. With regard to the terms of reference for consultant, and the estimated consulting cost, the PUSATAB and BBWS C3 (PEA) will need to have a consultation and agreement with Korea Eximbank. ① To maximize the benefits of a financing program (loan agreement) To maximize the benefits of its financing program, the Export-Import Bank of Korea (KEXIM) wants to build a water conveyance system whose quality and performance are assured; whose durability is secured for 50 years of the design life; whose operation is maintained in an organized manner; and whose service is not interrupted under any circumstances. All of these requirements will be satisfied only when the whole process is designed in a systematic manner; when key issues are perfectly examined; when a flawless working design is prepared; and when a thorough construction supervision is carried out by checking if every task of the work classification complies with the process; by testing the quality of materials; and by inspecting and testing the construction. ② To meet the international level quality standards International level quality standards are specified in the Korean Industrial Standards (KS) and Korean WaterWorks Association (KWWA) standards. For example, asphalt enamel currently used as an outer coating material for steel pipes in Indonesia is not allowed in Korea. So, materials that satisfy Korean standards will also assure the international level quality. As such, internationally accepted quality standards will be reflected in all the drawings of the working design and specifications and will be applied in the construction stage to test and inspect processes and performance. ③ To introduce an advanced quality management method 57