innovative wastewater solutions · 2018-01-17 · website: . wastewater sewerage and treatment...

Integrated Resources Management in Asian Cities: The Urban NEXUS South-East Asia

Innovative Wastewater Solutions

STUDY REPORT Wastewater Sewerage and Treatment System Coastal Settlement of Senggarang Tanjungpinang, Indonesia PN 15.2201.0-001.00

Prepared by Dr. Wolfgang Kirchhof, FiW

GIZ Integrated Resources Management in Asian Cities: The Urban NEXUS Programme

June 2017

Wastewater Sewerage and Treatment System Coastal Settlement of Senggarang

08.07.2017 2

Information used in this report is based on surveys during the short-term missions. Wrong interpretations might appear because of the use of outdated data.

Author: Dr.-Ing. Wolfgang Kirchhof Research Institute for Water and Waste Management at the RWTH Aachen Kackertstr. 17 D-52056 Aachen, Germany Tel.: +49-241-8026828 E-Mail: [email protected]

website: fiw.rwth-aachen.de

Co-Author: Kiki Prio Utomo, M.Sc Universitas TanjungPura Environmental Engineering Department – Engineering Faculty Kompleks Fakultas Teknik Universitas Tanjungpura Jl. Prof. Dr. H. Hadari Nawawi, Pontianak, Kalimantan Barat, 78124 Tel. +62-812562184 E-mail: [email protected] Tel.: +62-561-7053252 Fax: +62-561-740187 website: http://teknik.untan.ac.id

mailto:[email protected]

http://teknik.untan.ac.id/


08.07.2017 3

Table of Contents

0 EXECUTIVE SUMMARY .................................................................................. 6

1 INTRODUCTION .............................................................................................. 7

1.1 Background ........................................................................................................... 7

1.2 Structure of the study ............................................................................................ 8

2 FINDINGS ......................................................................................................... 9

2.1 Geography, climate ............................................................................................... 9

2.2 Population and Administration ..............................................................................12

2.3 Water Management in Senggarang ......................................................................14

2.3.1 Water supply ........................................................................................................14

2.3.2 Drainage and Wastewater treatment ....................................................................17

2.3.3 Rainwater collection .............................................................................................17

2.4 Analysis of key sanitary problems and opportunities.............................................18

3 PROPOSED WASTEWATER COLLECTION AND TREATMENT

PROJECT ................................................................................................... 19

3.1 Objective ..............................................................................................................19

3.2 Overview ..............................................................................................................19

3.3 Description of the process units of the proposed wastewater management

system ..................................................................................................................22

3.3.1 Process units of the sewerage system .................................................................22

3.3.2 Process units of the wastewater treatment system ...............................................24

3.3.3 Energy consumption .............................................................................................30

3.4 Cost estimation .....................................................................................................31

3.4.1 Cost estimation of the investment .........................................................................31

3.4.2 Cost estimation for the operation and maintenance of the sewer and

treatment system ................................................................................................34

4 PROJECT BENEFITS, IMPACTS AND RISKS ............................................. 38

4.1 Aspects before the construction ...........................................................................38

4.2 Aspects during the operation ................................................................................39

4.3 Potential for the enlargement of the system ..........................................................40

4.4 Potential for the water reuse .................................................................................41

4.5 Continuation of the system ...................................................................................43

4.6 Benefits ................................................................................................................44

5 REFERENCES ............................................................................................... 44

List of Figures

Figure 1-1 Survey team ...................................................................................................... 8

Figure 2-1 Aerial views of Bintan Island [Photos by author, 2016] ...................................... 9

Figure 2-2 Floating debris, degraded mangrove residuals at the Senggarang village [Photos by author, 2016] ................................................................................... 9

Figure 2-3 Monthly minimum, maximum and average air temperature in TanjungPinang district in 2013, 2014, 2015 .....................................................10

Figure 2-4 Monthly rainfall in TanjungPinang district in 2013, 2014, 2015 .........................10


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Figure 2-5 High tide and low tide in TanjungPinang district in 14 -22 Feb 2017 .................11

Figure 2-6 Seawards lying house in Senggarang during spring tide (Photo taken by Pak Jimmy, RT 1) ............................................................................................11

Figure 2-7 Disrupted water supply line and wastewater sewer pipe in Senggarang ...........12

Figure 2-8 Rotten and replaced pillars of a house in Senggarang .....................................12

Figure 2-9 Map of pilot area Senggarang with governmental administration boundaries (Kelurahan level) [Source: BPS Kota TanjungPinang, 2016, Google map, 2016] ..........................................................................................12

Figure 2-10 Map of pilot area Senggarang with governmental administration boundaries (RW/RT level) [Source: BPS Kota Tanjungpinang, 2016, Google map, 2016] ..........................................................................................13

Figure 2-11 Water delivery boat (left), community well with 20 water pumps and vendor service (right) [Photos taken by author, 2016] ......................................14

Figure 2-12 Elements of the public water supply system of Sengggarang ...........................15

Figure 2-13 as built drawing of site plan Senggarang of public water supply, phase 1 with 280 SR (house connections) .....................................................................16

Figure 2-14 Debris collection pond for interim storage before transportation to a dumping site ....................................................................................................17

Figure 3-1 Basic schema of the proposed wastewater management system for Senggarang .....................................................................................................19

Figure 3-2 Proposed wastewater management system for Senggarang and indicated locations for construction .................................................................................21

Figure 3-3 Proposed location for the vacuum station (left), location for the WWTP (right) ...............................................................................................................21

Figure 3-4 Vacuum collection chambers and connecting pipes, installed under houses and jetties [Photos by Bilfinger Water, 2017] .......................................22

Figure 3-5 Schema of the vacuum pump system, collection tank and vacuum station building [Photo by BILFINGER, 2016] ..............................................................23

Figure 3-6 Pressure line from collection tank to WWTP [Photo by author, 2016] ...............24

Figure 3-7 Layout plan of the proposed wastewater treatment plant for Senggarang ........25

Figure 3-8 Curved screen for separation of coarse materials, schematic (right) [Photo by author, 2016] ...............................................................................................26

Figure 3-9 Container vehicle to remove coarse materials [Photo by author, 2016] ............26

Figure 3-10 Schematic of an anaerobic reactor, type Imhoff tank [Imhoff, 2015]..................27

Figure 3-11 Anaerobic reactor and trickling filter [Photo by author, 2016] ............................28

Figure 3-12 Sketch of a trickling filter system [Pinnekamp, 2015] ........................................28

Figure 3-13 Sketch and photos of a rotating water distribution system for trickling filters [AWT Umwelttechnik, Eisleben GmbH, 2017] ..................................................29

Figure 3-14 Installation of filter media into a trickling filter reactor [Photos by NSW, 2016]................................................................................................................29

Figure 3-15 Sketch of vertically flown-through sedimentation basin [Pinnekamp, 2015] ......30

Figure 4-1 Motorized tricycle to collect solid waste [Photo by author, 2016] ......................38

Figure 4-2 Socket welding to connect vacuum pipes [BILFINGER, 2016] .............................39

Figure 4-3 Suction car to empty the vacuum sewer network after a electrical shut-down for more than 24 hours [Photo by author, 2016] ......................................40

Figure 4-4 Concept for the enlargement of the wastewater sewerage and treatment plant in Senggarang .........................................................................................41

Figure 4-5 Basic schema of the proposed wastewater management system for Senggarang .....................................................................................................42


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List of Tables

Table 2-1 Facts, characteristics, features in the Kelurahan of the Kecamatan Tanjungpinang Kota, 2015 ...............................................................................13

Table 2-2 Number and occupation status of the houses in Senggarang, based on the survey in October 2016 ....................................................................................14

Table 2-3 Design parameters of the water supply system ................................................17

Table 3-1 Cost estimation of the wastewater treatment plant including wastewater transfer line ......................................................................................................32

Table 3-2 Cost estimation of the sewer and wastewater treatment system in EUR ..........33

Table 3-3 Cost estimation of the sewer and wastewater treatment system in billion IDR ..................................................................................................................34

Table 3-4 Cost estimation of the sewer and wastewater treatment system, expressed in IDR .............................................................................................35

Table 3-5 Estimated monthly O&M cost per household connection for the sewer and treatment system, expressed in IDR ................................................................36

List of Abbreviations

Abbreviation Explanation

AR Anaerobic reactor

BOD5 Biochemical Oxygen Demand within five days at 20°C

COD Chemical Oxygen Demand

DWA German Water Association

FOG Fat, oil and grease

HH Household

IDR Indonesian Rupiah (here used: 1 EURO = 14000 IDR)

KK Kepala keluarga (“head of family”, households)

MBAS Methylene blue active substances

O&M Operation and Maintenance

SBR Sequenced Batch Reactor

SS Suspended solids

ToR Terms of Reference

TP total phosphor

WWTP, wwtp Wastewater Treatment Plant


08.07.2017 6

0 EXECUTIVE SUMMARY

The Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) is conducting the pro-ject “Integrated Resource Management in Asian Cities – The Urban Nexus”, financed by the Federal German Ministry of Cooperation and Economic Development (BMZ). The Urban Nexus Project started in 2013 over a period of 3 years. The follow up phase started in 2016 to come to an end by December 2018. The Asian partners are provided with technical advice on urban planning and development approaches that include the interrelations and synergies of the sectors: water, energy and food security such as secure water supply and sanitation systems, energy security and efficiency, land use, physical planning and food security. Tanjungpinang Municipality expressed their interest in the technology and requested the GIZ Nexus project to conduct a study on waste water collection and treatment in the coastal set-tlement of Senggarang (Subdistrict). The key characteristic of this settlement is that most the buildings are located on the sea on stilts; however, there has not been an establishment of a suitable sewer system yet. The study demonstrated potentials of the vacuum sewerage sys-tem for improvement of sanitation systems in the settlement. On this basis, a team of the Research Institute for Water and Waste Management at the RWTH Aachen University and of the Environmental Engineering Department of the Universi-tas TanjungPura conducted a study in September 2016 on the wastewater management in-cluding sewerage and treatment in Senggarang. It was stated that the vacuum sewerage system is the most feasible technology to collect domestic wastewater from houses on stilts. It was found that the physical conditions in Senggarang are feasible to build a wastewater treatment plant in a feasible distance. The team recommends using a multi-stage wastewater treatment process, consisting of a curved sieve to separate coarse materials, an anaerobic rector with the option to produce biogas, an aerobic trickling filter, and a sedimentation basin to separate solids from the treat-ed wastewater. The design of wwtp is selected to produce treated water that can be reused as new water resource for irrigation or raw water supply enrichment. The team has selected the design presented in such way that the capacity of the wwtp can easily be doubled by optimization of the reactors and modification of the operation modus

It is recommended that the project development is supported by accompanying methods,

such as training in wwtp operation and sewer maintenance.


08.07.2017 7

1 INTRODUCTION

1.1 Background

The Deutsche Gesellschaft für Internationale Zusammenarbeit German Agency for Inter-national Cooperation (GIZ) is conducting the project “Integrated Resource Management in Asian Cities – The Urban Nexus”, financed by the Federal German Ministry of Cooperation and Economic Development (BMZ). The Urban Nexus Project started in 2013 over a period of 3 years. The follow up phase started in 2016 to come to an end by December 2018. The Asian partners are provided with technical advice on urban planning and development ap-proaches that include the interrelations and synergies of the sectors: water, energy and food security such as secure water supply and sanitation systems, energy security and efficiency, land use, physical planning and food security. The GIZ Nexus team explored the vacuum sewerage system apt for flat terrain and high groundwater tables encompassing flexible routing and fluctuating usage. The GIZ Nexus, therefore, initiated vacuum sewerage technical training to improve the perspectives of sus-tainable wastewater management of the project’s partner cities. In February 2015, municipal officers from Tanjungpinang (Indonesia) attended the training in Bangkok with the objective of understanding the principle of vacuum sewerage technology and exploring opportunities for effective implementation of vacuum sewerage systems within local infrastructure.

Tanjungpinang Municipality expressed their interest in the technology and requested the GIZ Nexus project to conduct a study on waste water collection and treatment in the coastal set-tlement of Senggarang (Subdistrict). The key characteristic of this settlement is that most the buildings are located on the sea on stilts; however, there has not been an establishment of a suitable sewer system yet. The study demonstrated potentials of the vacuum sewerage sys-tem for improvement of sanitation systems in the settlement.

Results and findings are summarized in the Preliminary Study on Vacuum Sewer Systems – Pilot Project Area – Coastal Settlement of Senggarang, Tanjungpinang, Indonesia, August 2015, implemented by GIZ. In July 2016 on behalf of GIZ, a study was commissioned to develop innovative semi and decentralized solutions for the treatment of domestic (municipal) wastewater regarding water reuse options and energy saving option for the pilot area Senggarang in Tanjungpinang. Topics of this study are

Analysis and assessment of the findings of the preliminary study “Senggarang”

Development of appropriate, innovative, semi and decentralized solutions for the treatment of municipal wastewater regarding options for the generation of alternative water resources, water reuse

The consultancy comprised a preparatory work phase in Germany, a short-term mission of an international and national expert team from October 3 to October 10, 2016 in Tanjung Pinang, and an assessment work phase afterwards. On February 8, 2017, preliminary results of the study were presented to Mr Surjadi, head of BAPPEDA in Tanjung Pinang and his staff in the presence of the GIZ Urban Nexus Project. .


08.07.2017 8

1.2 Structure of the study

The study was conducted by a team of the Research Institute for Water and Waste Man-agement at the RWTH Aachen University and of the University of Tanjungpura, Pontianak as local partner.

Figure 1-1 Survey team

Methodology of the study

The team visited the village Senggarang in September 2016, joined a meeting at the Kantor kelurahan, and in a total of three days the visited all sub-districts (RW and RT), held inter-views with the local people, and visited a decisive point of interest in Bintan, water supply work, rainwater collection valley, solid waste dumping site and various land site that were introduced as possible sites for the construction of the wastewater treatment plant. At the bureau of statistic (BPS), at the office of public works (PU), BAPPEDA useful information was collected. The technical calculations for the sewer system and the wastewater treatment system were based on international standards and guidelines, as follows:

DWA- A 118 Hydraulic calculation of the sewerage systems, 2006

DIN EN 1091; DIN A 116 Vacuum sewer systems

DWA-A131 Calculation of single step wastewater treatment plants, 2016

DWA-T4/20176 Calculation of wastewater treatment plants in warm and cold climate zones, 2016

Wastewater Engineering, Treatment and Reuse, 4th edition, Metcalf & Eddy, 2004 Priority factors of the selection and assessment of the recommended concepts and actions are

Use and re-use of existing infrastructure, as far as possible

Low energy consumption

Adapted to local man-power and capabilities

Adapted to the local requirements

Acceptance of the users


08.07.2017 9

2 FINDINGS

General findings, geographical, climate, administrative features are described in the Chapter 2 “Rationale: Performance, problems, and opportunities in the Preliminary Study on Vacuum Sewer System, August 2015. In this report, additional findings are summarized that give up-dated and new information on the water supply and wastewater management of the pilot area around the Senggarang village.

2.1 Geography, climate

Geographically, Tanjungpinang is situated on Bintan Island where the position is between 0° 51 'North latitude up to 0° 59' North latitude and 104° 23 'East longitude up to 104° 34' East longitude, with an area of approximately 239.5 km2 consisting of land area of 131.54 km² and water area of 107.96 km².Tanjungpinang is located at an altitude of 0-70 m. above sea level and has the characteristics of hills, plains, swamps and mangrove forests. The conditions of the soils are classified as unsuitable for agriculture and plantations because of a red and yellow ground soil structure containing bauxite, an aluminum ore with high acidity. The soils also consist of granite, diorite and sandstone which formed rocky-hilly areas.

Figure 2-1 Aerial views of Bintan Island [Photos by author, 2016]

The surface cover of Bintan Island is widely modified due to bauxite mining activities and new settlement foundations. As these infrastructural works didn’t use environmentally friendly protection standards, the surface waters, such as rivers and lakes are widely affected by the mobilized red-soils from the construction sites. According to an interview at the UMRAH Uni-versity, the seawater resources and seawater banks are polluted by various sources, gener-ated on the Bintan Island. The coastal environment around the Senggarang village is degraded and polluted by floating debris that mainly generated in the village itself, but also arriving from the neighboring villag-es (Kampung Bugis).

Figure 2-2 Floating debris, degraded mangrove residuals at the Senggarang village [Pho-

tos by author, 2016]


08.07.2017 10

Air temperature The average air temperature is 27.2 °C (Maximum at 33.0 °C, minimum at 22.0 °C), meas-ured as average of the years 2013 – 2015. The pattern of temperature of this period shows a balanced process between rainy and dry season. (Info: The temperature is the decisive fac-tor influencing the speed of process in the biological wastewater treatment.)

Figure 2-3 Monthly minimum, maximum and average air temperature in TanjungPinang

district in 2013, 2014, 2015

Rainfall The average rainfall is 242 mm/month, measured as average of the years 2013 - 2015. The pattern of the rainfall data of this period shows an irregular distributed, indicating no clear dry or wet season. There is a decreasing trend and irregularities in the rainfall data. There is no clear definition into a dry and wet season. (Info: Due to the irregularity, there should be taken pre-caution measures to bridge the gap, when no water will be available and the water sup-ply might be disrupted.)

Figure 2-4 Monthly rainfall in TanjungPinang district in 2013, 2014, 2015

High tide and storm events The maximal tidal range in Tanjungpinang is 2.25 m (7.4 ft). The period between spring tides is 24 to 32 days. The average range in the (randomly chosen) period between 14 and 21 February 2017 is about 0.76 m.

10,0

15,0

20,0

25,0

30,0

35,0

Jan.

13

Feb.

13

Mrz

. 13

Apr.

13

Mai.

13

Jun.

13

Jul. 1

3

Aug.

13

Sep.

13

Okt.

13

Nov.

13

Dez.

13

Jan.

14

Feb.

14

Mrz

. 14

Apr.

14

Mai.

14

Jun.

14

Jul. 1

4

Aug.

14

Sep.

14

Okt.

14

Nov.

14

Dez.

14

Jan.

15

Feb.

15

Mrz

. 15

Apr.

15

Mai.

15

Jun.

15

Jul. 1

5

Aug.

15

Sep.

15

Okt.

15

Nov.

15

Dez.

15

Tem

pera

ture

[°C]

2013 - 2015

Tanjungpinang Municipality District

Temp.max. [°C]

Temp.min. [°C]

Temperature [°C]T max = 33,0 °CT min = 22,0 °CT average = 27,2°C

0,0

100,0

200,0

300,0

400,0

500,0

600,0

700,0

Jan.

13

Feb.

13

Mrz

. 13

Apr.

13

Mai.

13

Jun.

13

Jul. 1

3

Aug.

13

Sep.

13

Okt.

13

Nov.

13

Dez.

13

Jan.

14

Feb.

14

Mrz

. 14

Apr.

14

Mai.

14

Jun.

14

Jul. 1

4

Aug.

14

Sep.

14

Okt.

14

Nov.

14

Dez.

14

Jan.

15

Feb.

15

Mrz

. 15

Apr.

15

Mai.

15

Jun.

15

Jul. 1

5

Aug.

15

Sep.

15

Okt.

15

Nov.

15

Dez.

15

Mon

thy r

ainf

all [

mm

/mon

th]

2013 - 2015

Tanjungpinang Municipality District

Rainfall [mm]

annual rainfall2013: 3378 mm 2014: 3066 mm 2015: 2257 mm


08.07.2017 11

(https://www.tide-forecast.com/locations/ Tanjung-pinang/tides/latest)

Figure 2-5 High tide and low tide in TanjungPinang district in 14 -22 Feb 2017 At spring tide the floors of the seawards lying houses in Senggarang become submerged. (Info: The tidal range will limit the time for construction of the collection chambers under the floors of houses and the easy access in case of emergency, when e.g. the chamber outlet is clogged.) The collection chambers and the control devices, such as vacuum valves should be resistant to get submerged by seawater. The bottoms of chambers might be completely under water.

Figure 2-6 Seawards lying house in Senggarang during spring tide (Photo taken by Pak

Jimmy, RT 1)

The inhabitants of Senggarang reported about one to three heavy storms per year, causing heavy wave movements with destructive power in the seashore zone, destroying gangways and pipe connections. (Info: The vacuum sewer lines should be firmly fixed and protected against strong wave movements, particularly in the seashore zone.)

https://www.tide-forecast.com/locations/

https://www.tide-forecast.com/locations/


08.07.2017 12

Figure 2-7 Disrupted water supply line and wastewater sewer pipe in Senggarang

Seawater corrosion Seawater erodes wooden pillars, especially if soft wood is used. There is a regular exchange of rotten pillars by new ones. As the old pillars remain at place, the space for the installing of the collection chambers is reduced and the easy access to the chambers will be hampered.

Figure 2-8 Rotten and replaced pillars of a house in Senggarang

2.2 Population and Administration

The pilot area – the Senggarang village is part of the Kelurahan Senggarang, which is one of four Kelurahan of the Kecamatan Tanjungpinang kota (Fig.2-9).

P. Penyengat

P. Terkulai

SenggarangKp. Bugis

P. Los

Kota

Kel. Senggarang

Kel. Penyengat

Kel. Kp.Bugis

Kel. Tanjung

Pinang Kota

P. = Pulai (isle), Kp. = Kampung (village),

Kel. = Kelurahan (Sub-District), Kec. = Kecamatan (District)

Pilot area

Kel. Air Raja

Kel. Kamboja

Kelurahan Galang,

Kota Batam

Figure 2-9 Map of pilot area Senggarang with governmental administration boundaries

(Kelurahan level) [Source: BPS Kota TanjungPinang, 2016, Google map,

2016]


08.07.2017 13

Official statistical data are available up to the Kelurahan level. Information of features (num-ber of inhabitants) of smaller administrative units, such as villages, RT and RW, are only available on local data holding institutions.

Table 2-1 Facts, characteristics, features in the Kelurahan of the Kecamatan Tanjung-

pinang Kota, 2015

Feature Number Unit Year

Area 23,0 / 23,0 / 14,39 km² 2013 / 14 / 15

Population

Number of Families 1293 / 1299 Families 2013 / 2014

Size of families 3 / 3 Inh./family 2013 / 2014

Inhabitants 4162 / 4139 / 4448 Reg. persons 2013 / 14 / 15

Inhabitants of Senggarang 1243 /1300 Persons Prel. study 2015

/ survey Oct 16

Population density 180 / 287 / 309 persons/km² 2013 / 14 / 15

Administration

Number of RW and RT 7 / 16 RW / RT 2015

Number of RW and RT in

Senggarang

5 / 10 RW / RT 2016

Activities for living

Permanently employed 12,22 % 2015

Day labourer 16,21 % 2015

Fishermen 24,07 % 2015

Merchant 35,55% 2015

Government employee 1,81 % 2015

Others 10,15 % 2015

RW III / RT 2

RW III / RT 1

RW II / RT 2

RW II / RT 1

RW I / RT 2

RW I / RT 1

RW IV / RT 2

RW IV / RT 1

RW VII / RT 2RW VII / RT 1

Figure 2-10 Map of pilot area Senggarang with governmental administration boundaries

(RW/RT level) [Source: BPS Kota Tanjungpinang, 2016, Google map, 2016]

The village of Senggarang is located at the northern seashore of the Tanjungpinang belt. At the end of the western jetty (RW III / RT 2) is a station of the Indonesian marine force (TNI-


08.07.2017 14

AL), at the end of the eastern jetty (RW I / RT 1) the police station located. Half of the houses are on stilts, but many houses are temporarily empty and used only during seasonal events.

Table 2-2 Number and occupation status of the houses in Senggarang, based on the

survey in October 2016

Location Total number

of houses

Permanent oc-

cupied houses

Temporary oc-

cupied houses

On stilts, connected by jetties 250 155 95

On land, connected by roads 130 96 34

2.3 Water Management in Senggarang

2.3.1 Water supply The water delivery by boat from a private distributor is still practiced, delivering extra water during the dry season. The public community well at RW IV / RT 2 is still extensively used by the community RW IV/RT 2 using 20 private water pumps while the community of RW II and RW 1 are using a delivery service by a private vendor.

Figure 2-11 Water delivery boat (left), community well with 20 water pumps and vendor

service (right) [Photos taken by author, 2016]

Compared with the findings of the preliminary study of August 2015, some improvements are observed. With financial means from the central government programme (Public works pro-gramme), a public water supply system was established and set into operation. The system consists

a water collection,

a water treatment plant (WTP),

a piped water distribution and metering system.

Water from a natural pond, which is mainly re-filled by rainwater, is pumped by solar cell-powered two water pumps to a water treatment plant located uphill of the Senggarang village, west of the UMRAH university campus area. The WTP consists of a storage tank and a rapid sand filtration unit. From the WTP the water is led by a gravity transfer pipeline to Senggarang from where the water pipelines are connected to 280 households (SR, sambun-gan rumah).


08.07.2017 15

Natural pond, solar cells (left), jetty with two water pumps Water supply pumps

Water treatment plant

House connection with water meter

Figure 2-12 Elements of the public water supply system of Sengggarang

The as-built drawing of the site plan of Senggarang is shown in Figure 2-13. 280 house con-nections (KK) were installed in sub districts (RW, RT) as listed:

RT/RW 01/01 61 KK

RT/RW 02/01 46 KK

RT/RW 01/02 50 KK

RT/RW 02/02 38 KK

RT/RW 01/03 24 KK

RT/RW 02/03 19 KK

RT/RW 02/04 07 KK

RT/RW 01/04 19 KK

RT/RW 01/07 16 KK


08.07.2017 16

Figure 2-13 as built drawing of site plan Senggarang of public water supply, phase 1 with

280 SR (house connections)


08.07.2017 17

Design parameter of the water supply system is summarized in Table 2-3:

Table 2-3 Design parameters of the PU water supply system

Parameter Number Unit

Capacity of Water treatment plant 2.5 (2.0) Water flow [L/sec]

173 m³/d

Number of connected houses 280 house

Application range of the installed water meters 500 – 1000 L/d

Designed specific water use per house connection 617 L/House connection/d

Designed specific water use per inhabitant, if

3 persons per house connection

206 L/d/inhabitant

Designed specific water use per inhabitant, if

4 persons per house connection

154 L/d/inhabitant

2.3.2 Drainage and Wastewater treatment

Sanitation facilities and the sewerage system are described in the preliminary study, 2015. The wastewater from the houses at the jetties is directly dumped into the sea. The wastewater from the houses on the ground is led into septic tanks under the floor of the houses. The septic tank overflows flow via open drains directly into the sea.

Figure 2-14 Debris collection pond for interim storage before transportation to a dumping

site

No records on the maintenance of the septic tanks are available. No improvement of the management of the floating debris clogging the drains was seen compared with the condi-tions in 2015.

2.3.3 Rainwater collection

Rainwater is occasionally collected at some houses, using plastic buckets to collect the run-off from roofs of houses. A structured rainwater collection system in Senggarang is not in-stalled.


08.07.2017 18

2.4 Analysis of key sanitary problems and opportunities

Compared with the findings of the survey in August 2015, there is some progress in the pub-lic water supply system. Yet, the infrastructural works for a functional water and wastewater management in Senggarang are still limited.

There are new infrastructural developments for the improvement of the public water supply system. A WTP with a capacity of 2.5 l/s and a pipe distribution network with 280 house con-nections (SR) are installed. As the system is newly installed, records of maintenance and operation are not available. According to the supervising personal, the water supply pumps don’t reach their designed capacity as the solar power delivered by the solar panels installed are not sufficient during cloudy days. Furthermore, community members have indicated that there will likely be shortages of raw water pumped from the pond during dry seasons. A satis-faction survey in Senggarang was not conducted. The municipality of Tanjungpinang plans a second development phase to connect additional 80 houses more and to increase the raw water intake by installing a groundwater well, which will be located on the WTP ground. The well will be 160 meters deep, a submerged pump (GRUNDFOS) will be installed in a depth of 100 meters to supply additional 1.5 l/s ground-water as raw water. On the land part, a drainage system is partly existing, but widely clogged by debris. The houses on jetties have no drains. Conventional drains using gravity flow were tested, but failed due to the low height difference between the houses and the discharge point.


08.07.2017 19

3 PROPOSED WASTEWATER COLLECTION AND TREATMENT PROJECT

3.1 Objective

The objective of this study, based on the findings and inputs of the preliminary study of Au-gust 2015, is to provide solutions for an appropriate wastewater management system includ-ing sewerage, wastewater treatment, and options for water reuse.

3.2 Overview

The proposed wastewater management system (Fig. 3-1) consists of the wastewater collec-tion, the wastewater treatment, and water reuse options.

Discharge pump

of vacuum

station

Water storage

and flow

equalization tank

Screening

(Curved screen)

Coarse

materials,

plastics

Anaerobic waste

water and sludge

treatment

(Imhoff tank)

Treated sludge for

reuse (fertilizer)

Aerobic waste water

treatment

(Trickling filter)

Settler with

Sludge

separationTreated wastewater

for reuse

(irrigation,

raw water recharge)

Wastewater from

households

Sludge recyle pumpWaste

collection bin

Coarse materials to dumping

site or incinerator

Waste water

collection

Vaccum

pump

Household

Screen

Wastewater from

households

Waste water

collectionHousehold

Screen

Houses on stilts (Phase 1)

Houses on ground (Phase 2)

Collection

Treatment

Reuse

Figure 3-1 Basic schema of the proposed wastewater management system for

Senggarang

A vacuum sewer system is selected as wastewater collection system.

The vacuum sewer system is the most appropriate collection system as this system can be operated in environments where no gravity slope between the points of discharge and transfer is available. Recent references on vacuum sewer systems are Maledives, [Bilfingers Water, 2016] and Danang, Vietman [Bilfinger Water, 2016].


08.07.2017 20

A combination of an anaerobic and an aerobic wastewater treatment is proposed as a wastewater treatment system.

The wastewater management system operates as follows:

1. Wastewater (faeces) is drained by gravity from the toilets and wastewater sinks of the

houses to a small vacuum collection chamber, installed under the house floor

2. Theses collection chambers serve as an interim storage (interface) between the gravity pipe from the houses and the vacuum sewer network.

3. The wastewater is collected in the sump of the chamber. The wastewater is evacuat-ed from the sump through a membrane vacuum valve and transported through the vacuum sewer network to the big collection tank (vacuum tank) at the vacuum station. According to the filling rate of the chamber about 10 times per day the sump will be emptied.

4. It is recommended that the collection of the wastewater from the Senggarang is done in two subsequent phases. In phase one only the houses (without a septic tank) on stilts are connected. In phase two the other houses (with or without septic tank) locat-ed on the ground are connected.

5. At the vacuum station the wastewater is collected in the vacuum tank and then pumped via a pressure pipe to the wastewater treatment plant.

6. The vacuum station hosts the set of vacuum pumps that generates the vacuum pres-sure in the network, and the bio-filter that reduce the odor of the waste gas released from the vacuum tank.

7. By means of a curved screen coarse materials are separated from the wastewater stream pumped from the collection tank. The screen is placed on top of the anaerobic reactor, enabling a direct collection of the solid waste in transportable collection bins.

8. The screened wastewater is led by gravity into an anaerobic reactor that is construct-ed like an Imhoff tank with inner separating walls forming collecting chambers for the wastewater. The wastewater remains inside the reactor for about 20 days enabling a reduction of the organic materials, a separation of solids from the liquid phase and the generation of biogas. The top cover of the chambers is formed to collect digestion gas. The solids are settled down in sludge collecting chambers from where the solids are led by gravity into movable sludge containers.

9. The liquid phase is led by gravity to a trickling filter that operates as aerobic reactor. Organic materials are converted through an oxidizing process. Ammonium compo-nents are converted to nitrates as far as possible. The oxidizing process generates bio-solids.

10. The effluent from the trickling filter is led into a secondary sedimentation basin sepa-rating solids from the liquid phase. In accordance to the solid concentration and the sludge volumetric index a portion of the liquid phase and the sludge phase are pumped back into the anaerobic reactor or trickling filter. The remaining liquid phase is released as treated water ready to be used as raw water for water reuse applica-tions.


08.07.2017 21

11. Water reuse applications might be irrigation or water recharge into a raw water source of the Senggarang system. Further analysis is necessary to decide about the appro-priate and acceptable technology.

12. In the anaerobic process digestion gas, consisting of methane (CH4), carbon dioxide (CO2), sulphuric hydrogen (H2S), water vapour (H2O), hydrogen (H2), and other gase-ous components, is produced. As the designed size of the anaerobic digester is only about 60 m³, it is expected that the total amount of biogas is so low that it will be diffi-cult under local conditions to collect and utilize the biogas. The process should be ob-served and could be considered for a later development stage in case the waste wa-ter treatment plant is expanded to treat more wastewater, e.g., from Kampung Bugis.

Proposed location of the wastewater collection and treatment plant

The proposed wastewater management system requires land of about 30 m² for the vacuum

station and land of about 250 m² for the waste water treatment plant. In Senggarang loca-

tions for both systems could be made available. As location for the vacuum station, the

watchmen (RONDA) house and the parking space in RT 02/04 would be suitable. For the

WWTP, the area behind the Chinese cemetery in RT02/04 could be used (see Figure 3-2).

Figure 3-2 Proposed wastewater management system for Senggarang and indicated

locations for construction

Figure 3-3 Proposed location for the vacuum station (left), location for the WWTP (right)


08.07.2017 22

3.3 Description of the process units of the proposed wastewater management

system

3.3.1 Process units of the sewerage system

3.3.1.1 House connections, house collection chambers, connection pipes

Each house will be equipped with one collection chamber that will be mounted under floor.

The chambers are completed with a vacuum valve unit and are flood proof and seawater

resistant.

Collection chamber Collection chamber with

vacuum valve unit Collection chamber installed under wooden floor

Collection chamber, view from below

Connection pipe under floor with typical z-type vacuum fitting

Connection pipe under floor

Figure 3-4 Vacuum collection chambers and connecting pipes, installed under houses

and jetties [Photos by Bilfinger Water, 2017]

3.3.1.2 Vacuum station, Wastewater collection tank

It is proposed that the vacuum station elements are installed in the RONDA building (see

Fig.3-3). Using this building, the construction costs for a new building can be saved. The

components consist of:

Inside the RONDA building

Three vacuum pumps, each of 4 kW. The vacuum pumps will be placed in a rack.

This system can be easily extended by another additional vacuum pumps in case of a

later foreseen extension of the sewer system (Phase 2).

Air conditioner (AC) to keep the room temperate below 35 °C. An AC is less noisy

than a ventilator system.

Electrical cabinet for the control of the vacuum and wastewater pumps

Emergency generator, to provide electricity in case of interruption of the electrical

supply from outside

Outside the RONDA building


08.07.2017 23

One wastewater collection tank (vacuum vessel) of 7 m³ that will be located in an ex-

cavated pit next to the RONDA building. The tank will be placed so deep that later the

place can be used as parking space. Requirements: Concrete buoyancy protection,

upper concrete structure and a stainless steel cover are required.

Bio-filter unit to clean the exhaust air that will be released out of the vacuum sewer

pipeline. An active carbon filter will reduce the smelling gas components, purifying the

exhaust gas before emitting out to the environment. Requirements: The filling (special

granulate) of the active carbon filter system should be changed every 1 – 3 years,

depending on the operation of the vacuum station.

Two waste water discharge pumps, each of 4 kW, Flow- rate up to 30 m³/h

Figure 3-5 Schema of the vacuum pump system, collection tank and vacuum station

building [Photo by BILFINGER, 2016]


08.07.2017 24

3.3.1.3 Wastewater transfer line

The waste water discharge pumps pump the wastewater from the collection tank near the

vacuum station to the wastewater treatment plant, proposed to be behind the Chinese ceme-

tery. The wastewater is pumped directly to the curved sieve of the WWTP. The total length of

the line is about 350 m.

Figure 3-6 Pressure line from collection tank to WWTP [Photo by author, 2016]

The total pressure head consists of the vacuum pressure in the chamber, the physical head

difference between chamber and WWTP, the height of the construction of the curved sieve,

and the friction losses in the pipe system.

3.3.2 Process units of the wastewater treatment system

The wastewater treatment plant (WWTP) consists of following main process units:

a curved screen,

an anaerobic wastewater treatment reactor (type Imhoff tank),

a trickling filter (aerobic reactor) and

a secondary sedimentation.

Taking the local restrictions on the available land, these process units can be located as

shown on the layout plan (Fig.3-7).

The type of connecting pipe network between the Imhoff tank, the trickling filter and the sed-

imentation basin is chosen in such a way that one recycling pump can be saved compared

with a conventional system. This option requires a more frequent control of the recycle pro-

cess, but which can well managed by well trained professional plant operators.

The required land use is 240 m².


08.07.2017 25

Figure 3-7 Layout plan of the proposed wastewater treatment plant for Senggarang

Design basis

General flow data as measured or estimated:

Daily Wastewater quantity: 90 l/PE/day

Peak factor: 3

Persons (PE) connected: 1372 PE1

Specific organic load: 55 g BOD5/PE/day

Peak flow: 370 m³/day

Minimum flow: 85 m³/day

Flow pattern 12 h/day

Daily BOD load 75460 g BOD5 /day

Daily load of coarse material: 5 l/PE/day

For the design of the wastewater treatment plant the peak flow of 370 m³/day, calculated for the season in which all houses are occupied is taken.

3.3.2.1 Removal of coarse materials by a curved screen

Wastewater from the collection chamber is directly pumped into a curved screen system. The

pre-treated wastewater is then led into the anaerobic reactor.

1 The average number of persons living on Senggarang, expressed as persons (PE) connected (1372

PE), were calculated using the aerial view map and the site plan Senggarang of PU. For each sub-districts the number of houses, the sizes of the houses (Big /small), special buildings, and the rate of house occupations (-some houses are only used for some months - )

Imhoff tank

Water

effluent

Presure line

from vacuum station

Trickling

filter

Secondary

sedimentationTools store and

control building

Electric cabinetPump sump

Sludge recycle line

En

tra

nce

ga

te

Monitoring

box

| < - 20 meter - > |

| <

- 1

2 m

ete

r -

> |

Anaerobic wastewater treatment reactor

Sludge

container

0

1

5

12

Scre

en

Entrance gate

Optional: Gas collection and storage

Sludge

container


08.07.2017 26

The coarse materials are directly dumped into a waste container. The range of daily amount

of coarse materials is expected to be between 2.3 to 6.8 m³. This solid waste should be

transported to the waste dumping site on a regular basis. Depending on the amount of waste

trucks available (See Fig. 3-9), the waste has to be transferred between once a day and

twice a week.

Figure 3-8 Curved screen for separation of coarse materials, schematic (right) [Photo by

author, 2016]

Figure 3-9 Container vehicle to remove coarse materials [Photo by author, 2016]

3.3.2.2 Anaerobic wastewater treatment reactor

As primary wastewater treatment reactor an anaerobic reactor using a sedimentation cham-

ber and a sludge digestion chamber (see Figure 3-10) is proposed. This type of reactor is

based on the Imhoff tank design, which has been implemented many times. The organic

sludge settles in the upper chamber and slides down the inclined bottom slopes into the low-

er chamber, where it is stabilized by anaerobic processes. These processes release biogas.

The type of reactor can easily be enlarged by adding new chambers. In later steps the diges-

tion can be optimized by isolating the outer walls. The biogas that is generated in the diges-

Wastewater

from collection

chamber

Coarse materials

to waste container

Pre-treated

wastewater to

anaerobic reactor


08.07.2017 27

tion chamber can be collected in gas collection chambers, which can be mounted outside of

the main reactor. In case of unsatisfactory purification rates this reactor can be optimized by

adding additional units.

Sedimentation compartment

Digestion

compartment

Sludge

removal pipe

Sludge

storage

Optional:

Gas collection

Figure 3-10 Schematic of an anaerobic reactor, type Imhoff tank [Imhoff, 2015]

Design basis

Minimum hydraulic detention time: 0.5 h

Volume of the sedimentation chamber: 35.6 m³

Dimension: height 1 m (assumed)

Area 15.4 m²

Width 2.5 m

Length 6.2 m

Volume of the digestion chamber:

Retention time tR: 60.0 days

Specific sludge generation: 1 L/PE/day

Inlet load: 1000 PE/day

Volume of sludge storage: 60.0 m³

Dimension: height 1 m

Area 15.4 m²

Width (sludge) 3.5 m

height (sludge) 2.8 m

height of slope 1.4 m

Total height 5.2 m

Total volume 75.4 m³

It is recommended to design the anaerobic reactor and the trickling filter in such a way that

the feed-in from the anaerobic to the second reactor can be done using a gravity flow, as

realized in the example plant shown in Fig. 3-11.


08.07.2017 28

Figure 3-11 Anaerobic reactor and trickling filter [Photo by author, 2016]

3.3.2.3 Aerobic wastewater treatment by a trickling filter

Trickling filter systems are easy to construct and to operate. Wastewater is pumped up and

led through a rotating water distribution system into a round tank filled with fine gravels or

plastic elements that serve as settle media for the biomass. The tanks are flown through by

atmospheric air, delivering the necessary oxygen. Trickling filters, usable in a wide range of

COD loadings, can be used as

high loaded reactor for COD-elimination (reduction of carbonous substances)

low loaded reactor, installed after a first treatment unit as secondary treatment for ni-trification

In this application the trickling filter is used as second treatment unit to reduce carbonaceous

substances and to convert ammonium components to nitrate (nitrification).

Design basis

Organic load in inlet as BOD5 load 75 kg BOD5/day

Volumetric load 0.7 kg COD /m³

Inlet flow 30.9 m³/h

Volumetric load 0.3 kg/m³

Volumetric BOD5 load 0.35 kg/m³

Dimension

Height 3.5 m

Area 61.6 m²

Diameter 8.9 m

Figure 3-12 Sketch of a trickling filter system [Pinnekamp, 2015]


08.07.2017 29

Critical part of the trickling filter is the rotating water distributing pipe (Fig. 3-13). The pipe

should be rotating due to the jet force of the water coming out of the holes. This component

should be regularly checked.

Figure 3-13 Sketch and photos of a rotating water distribution system for trickling filters

[AWT Umwelttechnik, Eisleben GmbH, 2017]

The selection of an appropriate filter media depends on various factors. It is one of the most

expensive items for the trickling filter system. The range of cost is between 20 EURO/m³ for

lava clumps and up to 900 EURO/m³ for light-weight high-tech filter media. Depending on the

selected media, the required area and the required supporting construction vary. An appro-

priate technical solution is the application of particularly plastic stripes, which can be installed

at various densities into a reactor. It is recommended to start with a density of 200 m² stripes

/m³ reactor volume.

Figure 3-14 Installation of filter media into a trickling filter reactor [Photos by NSW, 2016]


08.07.2017 30

3.3.2.4 Sedimentation basin

Design basis

Surface specific flow 1.5 m³/m²/h

Inlet flow 30.9 m³/h

Required surface 20.6 m²

Required diameter 5.0 m

The effluent of trickling filter might contain fine dispersed biological sludge, which has to be

removed from the liquid phase before the release to a natural river or to a further water reuse

application. The required diameter is five meter. A round-shaped vertically flow-through sed-

imentation basin with a cone bottom is a typical shape. The sludge is collected in on the bot-

tom from where the sludge can be pumped back to the trickling filter or to the anaerobic re-

actor. As the size of reactor is less than 6 m, no rotating scraper is required to concentrate

the sludge to the bottom storage.

Figure 3-15 Sketch of vertically flown-through sedimentation basin [Pinnekamp, 2015]

3.3.2.5 Operation building and supporting equipment

A building of about 10 m² is required to host the electrical cabinet (front length of about 2 m),

tool boxes and a work bench for small repairs on-site.

It is recommended to install solar panels to supply a minimum of electrical power by solar

energy. Additionally, a battery-back-up is recommended to bridge gaps of power outages.

The treatment plant has not to be supervised by a permanent staff, but should be controlled

on a daily basis for about 1 to 2 hours.

3.3.3 Energy consumption

The sewer system and the wastewater treatment system need a total of about 46 kW of elec-

trical power. Main energy consumers are:

Sewerage system (26 kW)

• vacuum pumps (1 phase: 3 pumps x 4 KW, 2.phase: additional 3 pumps x 4 KW):


08.07.2017 31

The pumps are not operating continuously. Depending on the amount of wastewater,

which has to be pumped from the houses, the frequency is about 10 min every hour.

• air conditioning system for the vacuum station (2 KW)

Wastewater treatment system (20 kW)

• Wastewater pumps (2 x 4 KW) for wastewater pumping from VS to WWTP.

The pumps are not operating continuously. Depending on the amount of wastewater

in the collection vessel at the vacuum station, the frequency is about 20 min every

two hours.

• Wastewater recycling pumps (2 X 4 KW) for wastewater pumping from Sedimentation

basin to the anaerobic reactor or trickling filter

One pump is working continuously. On pump is discontinuously operating in de-

pendence of the sludge level in the sedimentation basin. The control can be done by

hand.

• Additional energy consumption for instrument controls, lighting system, estimated power

supply of about 4 kW.

The total electrical power supply is about 46 kW.

3.4 Cost estimation

The cost estimation is divided into two parts. Part 1 consists of the cost for the sewer system

including the wastewater transfer pump; part 2 consists of the wastewater treatment plant.

Two scenarios are considered:

In the scenario “Option stilt” the connection of the houses on stilts (250 houses) and the re-

lated wastewater treatment are regarded. It is assumed that the size of the WWTP is de-

signed to treat the maximum number of houses (380 houses).

In the scenario “Option ground” the additional connection of the houses on the ground (130

houses) is regarded. It is assumed that the WWTP is designed to treat the whole wastewater

amount without additional modifications.

3.4.1 Cost estimation of the investment

The cost estimation of the investment for the vacuum sewer system is based on the cost

calculation of the preliminary study. The costs are assumed lower than mentioned in the pre-

liminary study, as the total number of house connections was found to be smaller. Additional-

ly, the proposed use of an existing building (RONDA building in RT/RW 02/04) saves invest-

ment costs, and the distance between vacuum station and WWTP is shorter than previously

assumed.

The cost estimation for the wastewater treatment is based on equipment and construction

works, which can be purchased on the Indonesian market or which can be done by local

constructors.


08.07.2017 32

Table 3-1 Cost estimation of the wastewater treatment plant including wastewater

transfer line

Number /

amount

Item Cost in

EUR

Cost in

billion IDR

Wastewater transfer from vacuum station to WWTP

1 Pressure pipe sewer, fittings 10000 0,140

2 Wastewater pumps for transfer to WWTP 20000 0,280

Sum 1 30000 0,420

Anaerobic reactor

1 Concrete construction of reactor building 22631 0,317

1 Curved sieve and container 6000 0,084

1 Inlet building 4000 0,056

1 Fittings, measuring devices 2000 0,028

1 Gas collection system 3000 0,042

1 Pipe system 5000 0,070

Sum 2 42631 0,597

Trickling filter

1 Concrete construction of the reactor building 11688 0,164

1 Trickling filter media and supporting system 1) 23000 0,604

1 Rotating pipe for water distribution, central supply

pipe

12000 0,168

1 Recycle pipe system 4000 0,056

Sedimentation basin

1 Concrete construction of the basin 6174 0,086

2 Recycle pumps 5000 0,070

1 Recycle pipe line 4000 0,056

Sum 3 65862 0,922

Operation building

1 Concrete construction of operation building 20000 0,280

1 electrical, instrumentation and control engineering 20000 0,280

Sum 4 40000 0,560

Total sum 178493 2,50

Conversion factor EUR = 14000 IDR

Note: 1) The cost for the trickling filter media doesn’t include transport cost from Germany to

Indonesia. A transport of a 40”-container will be required. The recommended filter me-dia is an innovative material that has a light weight, can easily mount and replaced. Because of the light weight a smaller supporting structure is required compared with standard filter media. For the required volume cost savings of 15,000-20,000 EUR can be assumed compared with standard filter media.

In Indonesia, the price for high quality (high pressure strength and water tight) concrete in

Tanjungpinang is estimated around Rp. 1,200,000 per m³ (including material and labour,

excluding tax). Construction tax in total is around 14% of construction cost (which is consist

tax when buying material (PPn) and tax for labour/worker salary (PPh)).


08.07.2017 33

The exact costs depend on the detailed design of the treatment system, which has to be

elaborated by an Indonesian engineering company. The costs were estimated in such way

that the real costs will most likely figure slightly below the estimation.

Table 3-2 Cost estimation of the sewer and wastewater treatment system in EUR

Item Option Stilt

250 HH

Option

Ground

130 HH

Option Stilt +

Ground

Sewerage system (SS)

Collection chambers 400,000 270,000 670,000

Pipe network 300,000 250,000 550,000

Vacuum station, vessel, vac.

pumps

120,000 80,000 200,000

Summary SS 820,000 600,000 1,420,000

Wastewater treatment plant (WWTP)

Pressure pipe sewer incl. 2 dis-

charge pumps

30,000 30,000

Anaerobic treatment unit, sieve 43,000 43,000

Trickling filter and settler 66,000 66,000

Operation building 40,000 40,000

Summary STP 179,000 0 179,000

Summary SS+ STP 1,000,000 600,000 1,600,000

Investment costs for the vacuum sewer for the houses on stilts and the wastewater treatment

system amount to EUR 1,000,000. The same services for the houses on stilt and on ground

amount to EUR 1,600,000. The cost is excluding any taxes, duties, governmental levies, land

cost, and contingencies (15%).

Using a conversion factor of 1-14000, cost were expressed in Indonesian Rupiah and listed

in Table 3-3. The total amount is 14 billion IDR for the stilt houses and 22.4 billion IDR for the

stilt and ground houses.

.


08.07.2017 34

Table 3-3 Cost estimation of the sewer and wastewater treatment system in billion IDR

Item Option Stilt

250 HH

Option

Ground

130 HH

Option Stilt +

Ground

Sewerage system (SS)

Collection chambers 5.7 3.8 9.5

Pipe network 4.3 3.6 7.8

Vacuum station, vessel, vac.

pumps

1.7 1.1 2.9

Summary SS 11.7 8.6 20.2

Wastewater treatment plant (WWTP)

Pressure pipe sewer incl. 2 dis-

charge pumps

0.42 0.42

Anaerobic treatment unit, sieve 0.60 0,60

Trickling filter and settler 0.92 0.92

Operation building 0.56 0.56

Summary STP 2.50 0 2.50

Summary SS+ STP 14.0 8.6 22.4

3.4.2 Cost estimation for the operation and maintenance of the sewer and

treatment system

The cost for the operation and maintenance (O&M) of the wastewater collection and treat-

ment were estimated, based on following sub-items (summarized in Table 3-4):

1. Labour cost 2. Cost for electrical consumption 3. Cost for removal and transport of the coarse materials and sludge 4. Cost for replacement of the major used materials and items.

The household specific O&M cost are based on the technical design of the option STILT,

(250 Households (the Senggarang part standing on stilts) will be connected and served.)).

Explanations to Labour cost: A total of four technicians is foreseen to operate and main-

tain both the sewer net and the wastewater treatment plant. One foreman and three service

men are foreseen. The minimum local wage of 2,358,454 IDR (UMR for Kepulauan Riau of

2017) is assumed for the estimation. The staff should be trained by the technical experts who

build the plant. Special knowledge on the operation and maintenance could be provided e.g.

by GIZ.


08.07.2017 35

Table 3-4 Cost estimation of the sewer and wastewater treatment system, expressed in

IDR


08.07.2017 36

Explanations for the electrical consumption cost: The maximum power consumption of

all pumps and technical instruments are 46 kW. The daily run time vary from item to item.

The vacuum pumps and the wastewater transfer pumps of the vacuum sewer system are

designed to run for about 25 % per day (25 % of 24 h). The wastewater treatment will oper-

ate continuously. A work load rate of 100 % is assumed for the estimation.

The tariff for the electrical consumption on Bintan Island is 1250 IDR/kWh [Information of

PLN, 2017]

The estimated monthly O&M cost per household connection for the sewer and treatment

system, expressed in IDR, divided in salary, electricity cost, transportation cost, and cost for

main consumables is summarized in Table 3-5.

Table 3-5 Estimated maintenance cost of the sewer system, expressed in IDR

Explanations for the cost for removal and transport of the coarse materials and the

sludge: There will be daily amount of solid waste, as coarse materials separated in the

curved sieve system (pre-treatment) and as sludge generated in the anaerobic reactor. -

These solid waste has to be collected in waste bins or in slurry chutes, which have to

transport by small to a dumping site. It is assumed that two daily tours will be necessary, at a

rate of 100,000 IDR per transport.


08.07.2017 37

Explanations for the replacement of used materials and items: The operation of the

sewer network and the wastewater treatment plant requires consumption materials, which

has to be replaced. The three most expensive materials that have to be replaced are the

trickling filter media, the exhaust gas filter media at the vacuum station, and the vacuum con-

trol valves at each household connection. Annual replacement cost for these items were es-

timated, using the total cost for one replacement divided by the guaranty life time spans. The

trickling filter media has to be replaced after 10 years, the gas filter media after three, and

the valves after five years. Listed unit costs are based on suppliers’ data.

Table 3-6 Estimated monthly O&M cost per household connection for the sewer and

treatment system, expressed in IDR

Kind of service monthly specific cost

[IDR/HH/ month]

Salary for operational staff 24.826

Electricity consumption of sewer and treatment plant 48.553

Transport of sludge and coarse material 15.789

Replacement of used materials, consumables 37.354

Total 126.522

Using this cost model, the total estimated monthly O&M cost per household connection is

about 126.522 IDR (= 9,00 EUR/household).

The cost estimation model doesn’t include taxes, depreciation cost, but indicates high specif-

ic cost. In further examinations, it is advisable to develop a business plan in order to support

cost saving methods and to develop a fair cost distribution system in view of the system us-

ers.

Costs saving potentials are seen for all sub-tasks:

As the electricity cost are most expensive cost, it might be favourable to assess the

benefit of installing solar panels to use solar energy driven pumps and to reduce the

dependence of a public power supply.

The salary for the operational staff might be reduced by involving local persons (e.g.

from Senggarang) in maintenance works of the sewer net. This will require appropri-

ate technical training.

The transport of sludge might be combined with the solid waste removal programme

for Senggarang. An integrated solid waste management plan should cover the re-

moval of solids from the wastewater treatment plant.

The time span, after which heavily stressed or loaded machines, pumps or filter me-

dia have to be repaired or replaced, depends on a correct handling. The period can

be prolonged by good maintenance works. On the wastewater treatment plant a well

trained professional team is required; on the household connection sites the coopera-

tion with the private users is necessary.


08.07.2017 38

4 PROJECT BENEFITS, IMPACTS AND RISKS

4.1 Aspects before the construction

Solid waste collection

In order to achieve good results of the wastewater collection and treatment, the basic infra-

structure in Senggarang has to be improved. As solid waste (dumped plastic bags) and de-

bris cause clogging in open water channels and sewers, a functioning waste collection sys-

tem should be installed. The collection using tricycles, which was installed in the last years

but was later abandoned, should be started again.

Figure 4-1 Motorized tricycle to collect solid waste [Photo by author, 2016]

Necessary preparations to introduce the vacuum sewerage system as a new technol-

ogy in Indonesia

The vacuum sewerage system is a technology that has not been applied yet in Indonesia.

Training courses have been conducted as well as visits to reference plants outside of Indo-

nesia. However, there should be more information campaigns and more cooperation with

Indonesian users and governmental agencies that are involved in the assessment of new

technology, such as Puslitbang PU (Research Institute of the Ministry for Construction). This

cooperation should be used to improve the understanding of the new technology and enable

the Indonesian central institutions to give support to institutions on provincial or municipal

level.

Socket welding

The socket welding is also a relatively new technology that is used to connect vacuum sewer

pipes. The standard method to connect pipes (e.g. for water supply) is the mirror welding

technique. This method is sufficient for small networks (inside houses or small complexes of

up to six houses), but not for bigger networks.

To ensure the necessary quality of the sewer network, the workers conducting socket weld-

ing and other pipe works should receive a special training. Such training could be done by a

drinking water company in Pontianak (PDAM Pontianak) which has a Training Centre with

the necessary capacity to deliver technical training and guidance in pipe works. Training can

be continued on site. The special training in pipe works should be extended not only to the

construction phase but also to the maintenance and operational phase (see section: 4.2 Op-

eration of the wastewater treatment plant).


08.07.2017 39

Figure 4-2 Socket welding to connect vacuum pipes [BILFINGER, 2016]

It is advisable to require socket welded pipe connections for the vacuum sewer network.

Gradient measurements with laser technology

The vacuum sewer system is suitable for areas with little to no slope between intake and

transfer point at the outlet. However the vacuum sewer network requires a constant gradient

of 0.2 % with a high accuracy, which requires the application of laser technology for the

measurements. To keep the network close to the ground surface, lift pipes are installed

where necessary, forming a so called “saw-tooth-profile”.

For the construction, it is advisable to require gradient measurements with laser technology.

Operation of the wastewater treatment plant

The proposed wastewater treatment plant is designed under the premise of low energy con-

sumption and low land use. The plant is built in a compact way; the reactors fulfil multiple

functions, such as interim storage, reduction of settable solids, reduction of carbonaceous

substances, and reduction of nitrogenous substances. The connecting pipe system connects

the various compartments of the reactors. The operation of such a compact wastewater

treatment plant requires some in-depth knowledge of the functions of all parts installed.

It is advisable to train two to four persons with basic technical knowledge and talent in a spe-

cial training course on wastewater treatment.

4.2 Aspects during the operation

Both, the sewer and the wastewater treatment system are not maintenance-intensive. The

normal operation tasks are limited to the inspection of the network and the daily control of the

wastewater plant. For the normal operation, a team of up to three technicians should be

founded for the daily routine works. On household or village quarter level (RT or RW level), it

is advisable to instruct a contact person who will be in charge to collect complaints (on clog-

ging, mal-functions) and inform the supervising institutions (Kelurahan level).

There might be some emergency cases, such as clogging, pipe damages caused by strong

waves or interruption of the electrical power supply. For these cases, some measures have

to be prepared:


08.07.2017 40

All measures at the sewer network and wastewater treatment plant have to be done by quali-

fied and skilled technicians and not by the local people.

There should be a technical team available on Bintan Island, which will be able to reach

Senggarang in between a period of one day after receiving a notice of emergency (clogging,

pipe damage).

In case of a period without electrical supply of longer than one day, there should be a suction

truck available, by which the network can emptied. The sludge that is removed by the truck

should be transported to the solid waste disposal plant.

Figure 4-3 Suction car to empty the vacuum sewer network after a electrical shut-down

for more than 24 hours [Photo by author, 2016]

In consultation with the sewer net supplier it has to be decided whether a flushing of the

sewer network with inert gas (nitrogen) is necessary to restart the vacuum sewer system.

As mentioned in the preliminary study, there will be a provision of a warranty of one year

after the date of commissioning and supervision support during installation. After this period,

a service-agreement between the supplier and the Tanjungpinang Municipality must be pre-

pared and set into operation.

In Tanjungpinang, the responsible supervising sub-unit of the municipality should be capable

to react in case of emergency. This implies also storage of spare-parts to repair broken

chambers, valves or pipes.

4.3 Potential for the enlargement of the system

The type of construction of the sewer and wastewater treatment system is selected in such a

way that it offers opportunities for further enlargement and developments. The capacity of the

WWTP (designed for 1300 PE) can be increased for the service of about 4000 PE without

major constructions.


08.07.2017 41

The wastewater treatment plants can be enlarged by the following measures:

Optimization of the Anaerobic reactor

1. By increasing the inlet flow (implies a higher specific load in the anaerobic reac-

tor)

2. By thermal insulation of the outer walls of reactor (Increases the reactor tempera-

ture -> increase of bio gas production)

3. By installation of biogas collection and storage chambers above the reactor (tech-

nically practical, if gas production is higher than 10 m³/day)

Optimization of the trickling filter

1. By increasing the inlet flow

2. By removal of the filter media and exchange with a more effective filter-media,

which supports a higher specific purification rate

Figure 4-4 Concept for the enlargement of the wastewater sewerage and treatment plant

in Senggarang

4.4 Potential for the water reuse

The treated wastewater will be clear, free of sediments, free of dispersed solids, containing

nitrates, low concentrations of organic substances, and low concentrations of germs. The

amount will be about 2 l/s. This water is suitable for irrigation, for enrichment of raw water

sources (rainwater pond, groundwater aquifers) or for barrier water to avoid seawater intru-

sion into the groundwater aquifer under Senggarang village.

Locations for the water reuse options in Senggarang are indicated in the overview map of

Senggarang. The existing water supply system is indicated as yellow line. Water from the

natural pond is treated in the water treatment plant (WTP) from where the water is led to

Senggarang. There will be a groundwater well near the WTP to enlarge the raw water

source.


08.07.2017 42

Figure 4-5 Basic schema of the proposed wastewater management system for

Senggarang

Water treatment

plant (WTP)

Pond, 2 solar-driven

water supply pumps

Wastewater

treatment plant

Vacuum

station

Houses on

stilts

Houses on

ground

Water transfer line

Groundwater well,

planned

Water reuse option:

Irrigation water ?

Water reuse option:

Infiltration to increase

raw water osuerce

Water reuse option:

Infiltration as barrier

for sewateer intrusion

?


08.07.2017 43

The vacuum station and the wastewater treatment plant are located north of Senggarang.

The treated wastewater will be produced at the WWTP. There are three options for the water

reuse.

Treated water can be infiltrated near the WTP, near the pond. This option will in-

crease the raw water source.

Treated water can be used as irrigation water for the small agricultural area directly

near of the WWTP

Treated water can be infiltrated into the ground in Senggarang. By this method, the

public well near the VS will be protected against infiltration of seawater.

These options are not further examined in this study. However it is worth to check their feasi-

bility.

4.5 Continuation of the system

Continuation of the system depends on the availability of operational and maintenance funds.

Sufficient operational and maintenance funds from the local government are questionable in

the long run. People are urged to find another source of funding to support operational and

maintenance costs. Biogas from the wastewater treatment plant and water reuse is two pos-

sible sources of income to cover operational and maintenance cost. Turning biogas and wa-

ter reuse into income for Senggarang can be started by establishing an organisation or cor-

poration to run and manage the system. Currently in Senggarang a foundation exists that

manages water supply for local inhabitants. The foundation could be an example for the fu-

ture wastewater corporation or the foundation could integrate the wastewater system into its

business.

Another possibility to support the continuation of system is through knowledge transfer and

dissemination. The project is a new technology in Indonesia and could be considered as the

first of its kind. People, who are involved in the project, especially during the construction and

operational phase, will gain new knowledge and skills that can be used later in other projects

involving pipe works and tank construction. The cooperation could provide consultancy and

contractor services for other similar projects in Indonesia. The cooperation which will be es-

tablished to manage the wastewater system could also develop training measures for tech-

nical works and provide training for other people or municipalities. All activities that have

been mentioned: consultancy, contractor service and training center, could be sources of

income to support the continuation of system.

To generate income to support the system a business plan should be elaborated with the

people in Senggarang. The business plan will become a blue print for activities to support the

system and for the future development of the system.


08.07.2017 44

4.6 Benefits

The introduction of new technologies creates opportunities for new cooperation and research

works.

In case of a successful operation, this location will be used as a reference for a new

environmental technology in Indonesia and will offer new business opportunities.

The new sewer and wastewater treatment plant and the water reuse options derived

from their operations offer opportunities for applied research works (e.g. for the near-

by University of Marine Resources Universitas Maritim Raja Ali Haji (UMRAH))

5 REFERENCES

AWT Umwelttechnik, Eisleben GmbH, 2017. AWT-Eisleben-Produktflyer_Drehsprenger.pdf,

2017.

Badan Pusat Statistik Kota Tanjungpinang Jl. W.R. Supratman No. 01 KM. X Tanjungpinang - Kepulauan Riau Website : http://tanjungpinangkota.bps.go.id/ e-mail : [email protected]

Badan Pusat Statistik Kota Tanjungpinang, Kecamatan Tanjungpinang Kota Dalam Angka 2013.

Badan Pusat Statistik Kota Tanjungpinang, Kecamatan Tanjungpinang Kota Dalam Angka 2014

Badan Pusat Statistik Kota Tanjungpinang, Kecamatan Tanjungpinang Kota Dalam Angka 2015.

BPS Kota Tanjung Pinang, https://tanjungpinangkota.bps.go.id/website/pdf_publikasi/Kota-Tanjungpinang-Dalam-Angka-2016.pdf

Bilfinger Water, (2017): Presentation of Aqseptence Group GmbH, Vacuum Sewerage and Recovery Systems, Hanau, 26 Jan 2017

Imhoff, K., and Imhoff, K. (2015) Taschenbuch der Stadtentwässerung, 26. edi., Oldenbourg Verlag München Wien.

Pinnekamp, J. and Assistents (2015): Abwasserreinigung, Lehrstuhl für Siedlungs-wasserwirtschaft und Siedlungsabfallwirtschaft der RWTH Aachen Umdruck.

http://tanjungpinangkota.bps.go.id/

mailto:[email protected]

https://tanjungpinangkota.bps.go.id/website/pdf_publikasi/Kota-Tanjungpinang-Dalam-Angka-2016.pdf

https://tanjungpinangkota.bps.go.id/website/pdf_publikasi/Kota-Tanjungpinang-Dalam-Angka-2016.pdf


08.07.2017 45

Annex Table of the estimation of the number of houses per RT/RW district and the number of households

Sub

group

RT standard big size

full-time

occupied

partly not

occupied

<1> <2> <3> <4> <5> <6>

<7> =

<6>*<1>

<5> =

<4>/<1>%

RT 1 64 2 52 12

long pier, police, rest,

temple 3,5 224 19

RT 2 75 1 31 44

old treatment plant PU,

temple, land 3,5 263 59

RT 1 44 1 27 17 Ibu Bunga (land), dense 3,5 154 39

RT 2 39 2 32 7

medical practise Dr Boby,

church (land) 3,5 137 18

RT 1 32 1 23 9 rest 3,5 112 28

RT 2 32 1 20 12

pier, TNI AL, water boat,

old hotel (land) 3,5 112 38

RT 1 33 6 31 2 land, school 3,5 116 6

RT 2 34 1 28 6 open well, VC 3,5 119 18

RT 1 23 0 18 5 land 3,5 81 22

RT 2 16 1 7 9 land 3,5 56 56

Sum 392 16 269 123 1372 31

Size of house Rate of house occupation number of

family

membersSpecial buildings, places

persons

per house

Rate of

house

occupation

[% of empty

houses]

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