Analysis of constraints and potentials for wastewater management in the coastal city of Manado, North Sulawesi, Indonesia

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Journal of Environmental Management 88 (2008) 1141–1150 www.elsevier.com/locate/jenvman

Analysis of constraints and potentials for wastewater management in the coastal city of Manado, North Sulawesi, Indonesia Markus T. Lasuta,1, Kathe R. Jensenb,, Ganesh Shivakotia a

Integrated Tropical Coastal Zone Management, Asian Institute of Technology, Bangkok, Thailand b Zoological Museum, Universitetsparken 15, DK-2100 Copenhagen, Denmark Received 18 September 2005; received in revised form 30 May 2007; accepted 6 June 2007 Available online 6 September 2007

Abstract Manado is the largest and most densely populated coastal city in North Sulawesi Province, Indonesia. The city is facing problems of wastewater discharged from various sources. These problems are driven by high population pressure, increasing economic activity, and low household income, in combination with inadequate organizational structure of government institutions for addressing the wastewater problems as well as for law enforcement. There have been no community initiatives to prevent or mitigate wastewater problems. Therefore, a wastewater management plan is urgently needed to prevent and mitigate pollution caused by discharged wastewater. In this paper we analyze the current situation with respect to environmental state, sources and treatment of wastewater, socio-economic and institutional capacities as well as community awareness. Constraints and potentials are discussed to give recommendations for an integrated wastewater management plan for the city of Manado. r 2007 Elsevier Ltd. All rights reserved. Keywords: Wastewater management; Environmental management; Coastal city; Manado; North Sulawesi; Indonesia

1. Introduction Discharge of untreated wastewater is a great concern due to its impact on the environment. This issue has been addressed in many ways in different countries. Integrated coastal management (ICM) is an approach, which addresses all problems in a holistic manner (Kawabe, 1998; Wu et al., 1998; Morton and Blackmore, 2001; Murthy et al., 2001; Nur et al., 2001; Yeung, 2001). However, in the city of Manado, North Sulawesi, Indonesia, the problem of urban wastewater has not been included in existing ICM plans. For a rapidly growing coastal city as Manado, wastewater management should be integrated in the ICM plan since quantity and quality of water flowing to the coastal ecosystem may affect the ecosystem as well as the health of the city population. Corresponding author.

E-mail address: [email protected] (K.R. Jensen). Present Address: Fakultas Perikanan dan Ilmu Kelautan, Universitas Sam Ratulangi, Jalan Kampus Unsrat Bahu, Manado 95115, Indonesia. 1

0301-4797/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.jenvman.2007.06.011

Since the majority of wastewater is discharged without any treatment, a wastewater management plan is urgently needed for the city of Manado. The rivers flowing through the city are in a state of pollution exceeding Indonesian, ASEAN, and international water quality standards (Lasut et al., 2005). The rivers are presently unsuitable for aquatic activities (e.g., aquaculture, irrigation, and tourism) and, moreover, cases of wastewater-transmitted diseases (e.g., diarrhea and dermatitis) occur frequently. Many alternative strategies can be applied to the management of wastewater: (1) on-site or off-site treatment, (2) high or low technology facilities, (3) post-treatment reuse or discharge to the environment, (4) concentration for reuse of the wastes removed during treatment or storage of these wastes in a safe manner. Other strategies focus on separation of wastewater flows and/or avoiding contamination in the first place (Karrman, 2001). The primary objective of this study is to identify and discuss constraints and potentials of the existing situation and conditions for formulating a wastewater management plan for the city of Manado. We present data on the

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natural settings and land use patterns, the current status of wastewater sources and impacts, the technical standards of existing facilities, the socio-economic settings and an analysis of the community’s environmental awareness. We then analyze potentials and constraints of these aspects in order to derive recommendations for a wastewater management plan in the city of Manado.

2. Methodology Three aspects were examined: (1) wastewater dischargerelated aspects (WRA); (2) community-related aspects (CRA); and (3) government/administration-related aspects (GRA). The WRA comprised identification of wastewater sources, treatments and impacts. Natural characteristics (land use pattern and natural settings; population and socio-economic settings) were included in this aspect. The CRA included the community’s environmental awareness (Pompeo, 1999; Hauger et al., 2002), the level of knowledge and attitudes related to solutions of wastewater discharge problems. The GRA included government institutional arrangement, regulations, policies, strategies, and actions, in which government/administrative parties play an important role. Secondary data were obtained from government and consultancy reports, while primary

data were obtained through interviews and observations in the field. Primary data were collected between August 2002 and June 2003. Two districts (Kecamatan Molas and Kecamatan Wenang) within the city were selected as study areas. Site selection was based on location close to the coastal area (including water-front) and being influenced by the watershed of the Tondano river (Fig. 1). Identification of wastewater sources in the city was done qualitatively, while information on wastewater treatment was done quantitatively for individual households using the criteria shown in Table 1. For analyzing wastewater impacts, the data collected in three rivers, Bailang, Maasing, and Tondano (Fig. 1), were used (Lasut et al., 2005). Land use was calculated using GIS (ArcView software and satellite imagery SPOT XS4). The CRA data were obtained through interviews with individual inhabitants and household surveys (family basis) using questionnaire technique with several topics, each consisting of several questions. The data were subsequently aggregated to calculate percentage for each topic. Sample size was determined according to Slovin (1960 cited in Sevilla et al., 1988) and sampling method of stratified random (Steel and Torrie, 1980) was applied. The GRA data were obtained from interviews with key informants in government offices and from reports.

Fig. 1. Map of the city of Manado with five districts (Molas, Mapanget, Wenang, Sario, and Malalayang) and three rivers observed for water quality in this study.

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Table 1 Criteria for toilet condition and capacity used in the present study Criteria

Residential septic tank Condition

Very Leaking to sewer poor Poor Open hole Adequate Closed hole, no concrete/cement Good Very good

Closed hole, concrete/cement, one compartment Closed hole, with concrete/cement, two compartments

Capacitya (liters per bedroom (a)/liters per person (b))

Condition of infrastructures and facilities connected to septic tank at house basis

With or without concrete/cement, littering by solid waste, no running water o1419.38 (a)/ o709.69 (b) No concrete/cement, littering by solid waste, running water 1419.38–1774.23 (a)/ 709.69–887.11 (b) With or without concrete/cement, no littering by solid waste, no running water 41774.23 (a)/ 4887.11 (b) With or without concrete/cement, with or without littering by solid waste, running water Concrete/cement, no littering by solid waste, running water

a

Standard: one bedroom equals septic tank volume of at least 1419.38 l for adequate capacity (Feachem et al., 1983; cited in Kusnoputranto, 1997); one bedroom corresponds to two persons.

3. Existing situation and condition of Manado City

Table 2 Land use and geomorphologic features of the city of Manado

3.1. Natural settings and population Manado, the capital city of North Sulawesi Province, Indonesia, is located at 11300 –11400 N; 1241400 –1241500 E. It is a developing coastal city forming a waterfront to Manado Bay (Fig. 1). In 2000, the population was about 418,000 individuals (81,892 households) with an annual growth rate of 3.4% and a density of 2637 individuals per km2. Geomorphology greatly influences land use pattern, since only flat land (slope 0–8%) is suitable for housing and commercial activities (Table 2). Therefore, settlement development is mostly distributed haphazardly and concentrated along the coastline. Six of 21 rivers discharging into Manado Bay are running through the city. The most important of these is the Tondano river, running from the Tondano lake in the upland area outside Minahasa Regency (Table 3a) (JICA, 2000). About 18% of the city area is included in the watershed of this river (Fig. 2). Also included in the city of Manado is part of the Bunaken National Marine Park (BNMP), where artisanal fishery and tourism are important activities. The area is affected by tropical monsoon climate with two different seasons, dry (May to October) and rainy (November to April). Meteorological data are shown in Table 3b.

3.2. Socio-economic aspects More than 50% of the inhabitants have incomes of less than Rp. 1 million (1 US$ ¼ Rp. 8500) and about 28% of the households have been categorized as poverty households (Mokat, 2003). Most people are employed in either small-scale operations or as civil servants of the local government. Unemployment is also a significant problem, 8.7% in 2000 (Mokat, 2003), though lower

Km2

Percentage (%)

Land use Mixed agricultural land Housing area Forest and mangrove Vacant & dry land Commercial area Rivers & canals Other uses Total area

112 33 7.4 3.3 2.8 0.8 1.7 161

69.5 20.5 4.6 2.1 1.7 0.5 1.1 100

Geomorphology Slope 0–8% Slope 8–40% Slope 440% Total area

122 37 2 161

75.8 23.0 1.2 100

Areas calculated using GIS (ArcView) and satellite imagery (SPOT XS4). Table 3 Hydrographical conditions: (a) Water discharge of the Tondano river (from JICA 2000); (b) Precipitation in the city of Manado (data from staff of Station of Meteorology and Geophysics, Manado) (a) Discharge

1985–1995 (m3/s1)

1999 (m3/s1)

Maximum Minimum Annual mean

22 5 14–17

16 (January) 13 (September) 15

(b) Precipitation

1991–2000

Monthly maximum (January) Monthly minimum (August) Monthly mean Annual average Rainy days Humidity (average 1997–1999) Average temperature (1994–2000)

407 mm 75 mm 251 mm 2000–2400 mm 90–120 per year 83% 26 1C

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Fig. 2. Tondano watershed with Manado City area.

unemployment (1.6%) was found in the present study (Table 4). The average economic growth was about 22.6% over the period of 1995–2000 (BPSKM, 2000). Agriculture, manufacturing industry, hotels and restaurant sectors were growing at a stable and significant rate. Tourism has been targeted for development and the BNMP is a promising area for development of a tourist destination (BPSPSU, 1999), which, after a drastic decrease in connection with the Asian economic crisis, has shown increasing trends in recent years for both international and domestic tourists (Table 5).

3.3. Wastewater sources, treatment and impacts 3.3.1. Sources of wastewater Point sources identified in the city include residences, hospitals, hotels, restaurants, garbage dumps, and aquaculture. Several of these are located close to rivers and canals and discharge all wastewater, in most cases including that from toilets, untreated to Manado Bay through ditches, sewers, canals, and rivers. Non-point sources are cultured fields, runoff from non-cultivated land, etc., which occur both within the city and in the hinterland of Minahasa Regency. These sources also drain

ARTICLE IN PRESS M.T. Lasut et al. / Journal of Environmental Management 88 (2008) 1141–1150 Table 4 Household survey on socio-economic parameters (%) Variables

Wenang District N ¼ 304

Molas District N ¼ 300

Age group (years) 20–60 460 No information

68.1 17.4 14.5

79.7 16.0 4.3

Employment Private company Civil servant Unemployed No information

70.7 26.0 1.6 1.6

74.7 21.7 – 3.7

Income per month oRp. 1 000 000 41 000 001 No information

64.5 16.2 19.4

68.7 15.6 15.7

Level of education Primary school Secondary school High school University graduate No information

2.6 8.2 61.5 27.3 0.3

13.3 19.0 53.7 13.7 0.3

a

a

1 US$ ¼ Rp. 8500.

Table 5 Number of tourists visiting the Bunaken National Marine Park (BNMP) in 2001–2005 Year

2001 2002 2003 2004 2005a Total Percentage

Tourism

Total

International

Domestic

5194 8263 762 9824 9495 33 538 31

9872 17 616 1901 28 177 17 857 75 423 69

15 066 25 879 2663 38 001 27 352 108 961 100

Data from Board of BNMP (pers. comm.). a Up to October 2005.

through the rivers and canals traversing the city to the bay. No data are available on the amount of wastewater from different sources.

3.3.2. Condition and capacity of on-site wastewater treatment and sewer system Most wastewater sources are located within the residential and commercial areas. No modern on-site system with advanced technology has been adopted for wastewater disposal. Most residential buildings have a private, traditional, on-site wastewater disposal system composed of a toilet with septic tank (one or two compartments); alternatively, a deep hole, ditch, and/or rivers are used. The latter is considered one of the main wastewater problems in the city.

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The condition and capacity of septic tanks and wastewater infrastructure and facilities in the districts of Wenang and Molas are shown in Table 6. Households having no septic tank may use the communal septic tank or sewers, canals, or rivers to discharge their toilets. Most of the public or communal-use toilets have septic tanks in poor condition. This is probably due to lack of funding for maintenance or lack of awareness of the users to keep them clean. Most of the septic tanks in Wenang district had poor capacity. This may cause leaking to sewers, another major wastewater problem in the city. 3.3.3. Impact of wastewater discharge Only one study exists on pollution load and water quality of the rivers running through the city of Manado (Fig. 1) (Lasut et al., 2005). The data from this study were difficult to interpret, but the measured values for most parameters exceeded national and international quality standards (Table 7). In addition, the rivers Malalayang, Sario, and Tondano gave positive tests for microorganisms (E. coli and Vibrio sp.) (PPLH-SDA Unsrat, 2000). Since the rivers are used for washing, bathing, fishing, and fish cage culture, the discharge of untreated wastewater poses a threat to community health. The number of cases of wastewater-transmitted diseases observed at the Community Medical Centers in several districts of the city is presented in Table 8. With increased economic growth and tourism activities, the public demand for improved sanitation levels in the urban area has also increased (Sukarma and Pollard, 2000). Clearly the city of Manado needs to implement a regular water quality monitoring program for the major rivers, especially for indicators of pollution with fecal and pathogenic microorganisms and toxic wastes, e.g., heavy metals. Heavy metals (indicated by Hg-tot) were detected in the water and sediment and accumulated in marine biota (bivalve tissues) at the mouth of the Tondano river (Table 7) (Lasut et al., 2005). 3.4. Environmental awareness Community participation in environmental management in North Sulawesi Province is increasing, as evidenced by the establishment of many environmental-focus nongovernment organizations (NGOs). Also, the community is increasingly contributing advice, criticism, and other inputs to development activities (Sompie, 2002), directly or indirectly through the government. However, in no case has the community of Manado city taken an initiative to prevent and mitigate the wastewater problems in the city. Interviews in Wenang and Molas districts showed that citizens are concerned about the general environmental conditions and human impacts, including those caused by wastewater, and they have good knowledge especially on environmental issues related to wastewater (Table 9). In addition, they have a positive attitude towards solving the problems; 490% of the households disagree with the statement that wastewater problems are either fully

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Table 6 Presence, condition, and capacity of residential septictank (% of houses) Residential septictank

Wenang District (n ¼ 304) 83.2 16.8

Present Absent

Molas District (n ¼ 300)

Wanea District/Tanjung Batu Sub-district (n ¼ 930) 85.3 14.7

75.0 25.0

Criteria for condition and capacity (see Table 1 for explanation)

Residential septictank condition

Condition of infrastructures and facilities at house basis

Residential septictank capacity

Wenang District (n ¼ 304)

Wenang District (n ¼ 304)

Wenang District (n ¼ 169) Volume per bedroom Volume per person

Very poor Poor

12.2 0.3

Molas District (n ¼ 300)

4.3 0.3

Molas District (n ¼ 300)

8.2 5.9

2.3 3.0

Molas District (n ¼ 163) Volume per Volume per person bedroom

45.0

35.0

37.4

11.2

10.4

9.8

43.9

54.6

52.8

55.0 Adequate

–

0.7

2.0

3.3 11.8

Good

15.1

23.3

4.9

38.0 33.1

Very good No information

30.9 24.7

37.0 9.3

62.2 16.8

52.7 0.7

Table 7 (a) Water quality standards; (b) Water quality status of the rivers in the city of Manado (a)

Government of Indonesia (mg/l)

Parameter

Class IIa

Class IIIb

BOD5 NO2 3 PO3 4

3 10 0.2

20 1

Hg-tot Fecal coliform E. coli

0.002

0.002

ASEANc (mg/l)

Internationald (MPN)

0.06 Estuaries: 0.045 Coastal: 0.015 0.16  103 200 200

(b) Parameter

BOD5 Dry season BOD5 Wet season NO2 3 Dry season NO2 3 Wet season PO3 4 Dry season PO3 4 Wet season Hg-tot Dry season Hg-tot Wet season Fecal coliform Dry season Fecal coliform Wet season E. coli Dry season E. coli Wet season

River Bailang

Maasing

Tondano

Malalayange

Molase

Sarioe

14.78 5.1/7.0e 1.49 0.93 1.56 1.67 – – 42400 42400 42400 42400

19.34 14.11 2.37 1.46 2.18 2.26 – – 42400 42400 1100 42400

12.48/16.46e 4.18 2.13 1.83 1.42 2.57 0.024 0.081 42400 42400 42400 1100

– 6.69 – – – – – – – – – –

– 5.44 – – – – – – – – – –

– 9.55 – – – – – – – – – –

In (b), Concentrations (mg/l) are averages of measurements from 4–5 stations (see Fig. 1) located within the city area; fecal coliform and E. coli are MPN (most probable number). a Water that may be used for recreational activities, fisheries, livestock, and irrigation (Tunggal, 2002). b Water that may be used for fisheries, livestock, and irrigation (Tunggal, 2002). c Marine water quality criterion for protection of aquatic life (Jusoh, 1999). d MPN ¼ most probable number (FAO cited in Clark, 1992). e Measurements from PPLH-SDA Unsrat (2000).

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a government or fully a community responsibility. Furthermore, 495% agree that all parties (government, community, private sectors, etc.) have a responsibility to address the problems, and 72% and 56% in Wenang and Molas, respectively, agree that the government may collect funds from the community in order to improve the quality of wastewater infrastructures and facilities. 3.5. Government institutional arrangement and regulatory aspects In January 2000, a national act regarding local autonomy for resource management and institutional arrangement was implemented. At the present time, however, responsibility for waste management is divided among several institutions, and no laws or regulations have been implemented at the local level for wastewater management. In the city of Manado, the Environmental Management Board (EMB) is responsible for management of wastewater (liquid waste) and this function is separated from the Cleaning Management Board (CMB), which has responsibility for management of solid wastes. Both institutions are under the Mayor’s Office. The City Table 8 Cases of diseases in Manado City in 2002a Districts (sub-districts) Diarrhea Molas (Tuminting) Wenang (Tikala Baru) Sario (Ranotana) Malalayang (Bahu) City hospital

b

Dermatitis Gastritis c

513 (58 /48 ) 1618 1250 27 253 288 777 1075 2725

b

Typhoid c

196 /272

10b,c

a The data were collected at Puskesmas (community’s medical centre) in each district. b October–December 2002. c January–April 2003.

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Company for the Market is the technical agency responsible for solid waste management within the market area. At the provincial level of North Sulawesi, the Provincial Agency of Environmental Impact Control Board (PAEICB) is only responsible for coordination of management and control of pollution, including the marine environment. At the national level, the National Agency for Environmental Impact Management (NAEIM) under the Ministry of Environment (MoE) is responsible for implementing pollution control, including the marine environment, as well as for managing the environmental impact assessment (EIA) process. National wastewater quality standards for various sectors (industries, hotels, hospitals, petrochemical activities) exist. ICM is the responsibility of the Ministry of Marine Affairs and Fisheries and thus has been focused mainly on natural resource management (Christie, 2005).

3.6. Policies, strategies, and actions Some measures of environmental management related to wastes and wastewater have been established at the national level in Agenda 21 of Indonesia (period of 1998–2020), as well as at the provincial level in Agenda 21 of North Sulawesi Province. The Agenda 21 strategies for wastewater management at the provincial level are to increase public service and improve the wastewater treatment facilities. The planned actions include establishing a central wastewater treatment system at the long-term level, and improving the current systems over short and intermediate terms, both for individual and communal facilities. Establishing a central wastewater treatment system with appropriate technology for households in densely populated areas will be included in the future action plan (Bapedal-SU, 2003). However, in the city of Manado few measures have been established, and only in

Table 9 Community’s environmental awareness (knowledgea and attitudeb) in the Wenang and Molas districts of Manado city Components and issues

Percentage of the aggregatedc aspects

A. Knowledge Knowledge about general environmental issues Knowledge about environmental issues related to wastewater

Wenang Molas Wenang Molas

N 304 300 304 300

Yes 49.0 27.3 88.8 80.0

No 51.0 72.7 11.2 20.0

Mode No No Yes Yes

Wenang Molas Wenang Molas

N 139 145 139 145

vc 15.8 23.4 18.0 20.7

c 47.5 61.4 57.6 56.6

ltc 32.4 13.1 20.9 18.6

B. Attitude Concern about general environmental conditions and impacts Concern about environmental conditions and impacts related to wastewater

lsc 3.6 2.1 3.6 3.4

ntc 0.0 0.0 0.0 0.0

nif 0.7 0.0 0.0 0.7

Mode c c c c

N: number of respondents; vc: very concerned; c: concerned; ltc: somewhat concerned; lsc: less concerned; ntc: not concerned; nif: no information; Mode: statistical calculation. a Based on interview with head of household. b Based on interviews with individual residents. c Each issue was addressed by several questions.

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a partial sense as tactical actions for short-term periods (Tamon, 2003). 4. Constraints and potentials analysis Based on the above information we have identified constraints and potentials. The constraints are generally related to the rapid population growth and unplanned development, whereas potentials are associated with economic growth and the community’s environmental awareness and willingness to participate in solving wastewater problems. As the population of the city will continue to grow, so will the demand for space for settlement with proper public infrastructures and facilities, including for wastewater handling. The limited amount of suitable land (Table 2) causes haphazard distribution of residential and commercial areas, especially along the coast. The result is formation of slum areas (4250 individuals/0.01 km2), which have been identified in three districts of the city (Kumurur, 2002a), including the districts of the present study. The unplanned development and uncertainty of spatial planning cause practical problems of land use changes in the city. Thus, development of land reclamation for settlements has been changed so that 95% is used for commercial activities (hotels, restaurants, malls, a.o.) in the coastal area (Kumurur, 2002b), and the area originally set apart for marine eco-tourism has been changed to a commercial area. This is likely to cause problems if these activities do not have proper wastewater treatment systems and discharge their sewage directly to the coastal water. The population pressure drives increasing amounts of wastewater and, due to the low household income, most housing developments are constructed with no or poor standard of wastewater disposal and treatment systems. Most domestic wastewater has the potential to pollute not only the urban but also the coastal environment because the wastewater always contains high concentrations of human and animal fecal material containing pathogenic microorganisms. Hospitals and other public buildings also discharge sewage, except from toilets, directly to the coastal waters through sewers that show high concentrations of wastewater indicators and furthermore contain toxic substances (Table 7). There is no system in place for control and monitoring of pollution from any sources; nor are there guidelines for setting up such a system. The developers or businesses are advised to do self-monitoring and controlling the impacts identified in their EIA. This may easily act as constraints for the management. The non-point sources of wastewater from the hinterland of the regency of Minahasa are predicted to cause significant problems, but they are difficult to measure and no data are available. At the city level, the institutional arrangement with separate agencies responsible for liquid and solid wastes is

clearly inadequate, even if both institutions improve their function. Moreover, the EMB has not yet established any regulations. The community’s environmental awareness has potential regarding wastewater management. The community can be asked for their participation, including financial support as most of them are positive, but it is clear that government should assist them by improving the public infrastructures and facilities for wastewater discharge. So far the community has not participated in the management. This is probably because they have not been given this option by the government, and there are no signs that the government intends to help the community. Recently, the community has been asked to collect money for garbage handling. However, the problem of garbage handling remains unsolved. The establishment of policy measures as mentioned in Agenda 21 can be seen as a potential for wastewater management, both at national and provincial levels. However, it can also be a constraint, as the city has not applied them yet. 5. Suitable options of wastewater management strategy From the analyses presented above, suitable options for a wastewater management strategy for the city of Manado could be formulated fulfilling the following general objectives: (1) protecting the health of citizens from pollution and unhygienic conditions of wastewater; (2) protecting water quality of canals, rivers, and coastal area to support aquatic life, fishery and coastal resources. For the formulation we considered: (1) natural settings and land use of the city of Manado, and (2) the dynamics of the population, economy and commercial activities of the urban area. As the environmental condition of the city is closely related to conditions of the coastal waters of MB, the coastal environment should be assessed and the planning of wastewater management should be included in the ICM process. A decentralized system provides simple, low-cost and low maintenance methods of treating domestic wastewater (Burkhard et al., 2000). Since lack of finance is one of the main problems, such a system constitutes a suitable and possible solution to be applied in the city of Manado. Several models have been suggested for small communities ranging from the smallest, single household system to larger systems for a small community (Bakir, 2001). The smallest system is suitable for low-income residential areas, especially those sparsely populated and distributed haphazardly in the city. A small-scale conventional or modern wastewater treatment plant with low-level technology that can serve for a cluster of buildings is suitable for commercial centers (hotels, restaurants, and small industry), institutional buildings (hospitals, laboratories) and garbage dumps in the city. Clustered residential buildings, as those along the coastline of MB, are also suitable for such a system.

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The system may comprise several small subsystems for collection, treatment and reuse or disposal systems (Massoud et al., 2003). The size of each subsystem should be determined administratively based on drainage boundaries and prevailing social and economic conditions (Bakir, 2001). It is important for the success of this type of system that there are clear regulations identifying who will be responsible for the operation and management of such a wastewater treatment plant. Several models exist that may be suitable for adoption by the city: (1) agency, i.e., operation and management of wastewater implemented by selected local authority(ies) on an agency or local basis; (2) private operation, i.e., the plant fully owned and managed by private sector; (3) local government, i.e., the facilities managed by the local authority and owned by the public; (4) PS & PSP, i.e., the facilities owned by the public sector (PS), but managed by private enterprise (PSP) (Tsagarakis et al., 2001). Four strategic actions to be included in plans for wastewater management have been suggested for decentralized systems in a city. Some of them are based on the lessons learned from small communities in the Middle East and North Africa (Bakir, 2001): (1) providing and improving on-site wastewater treatment system and sanitation; (2) improving government’s institutional arrangement; (3) improving community’s participation; and (4) establishing regulations and enforcing them. Each of these strategic actions may form constraints to management measures, but they may be used as an entry-point for establishing such management. Hence we present below each of the four actions with appropriate modifications for the implementation. 5.1. Providing and improving on-site wastewater treatment system and sanitation Improvements of existing on-site wastewater systems to good standard and proper technology should be done by each household and owner of commercial buildings, in which case no tax or retribution needs to be levied by the government authority. However, low-income households need to be subsidized for obtaining such system. This action may also be seen as a measure to improve sanitation and pollution control. 5.2. Improving government’s institutional arrangement Rearrangement of government institutions is recommended. A management board should be set up, including the CMB, Public Works Agency (technical expertise), Public Health Agency and other associated institutions and with the EMB as the coordinator. 5.3. Improving community’s participation Although community participation is considered a potential, the awareness specifically related to wastewater

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management is still insufficient. Therefore, it is important to increase and improve participation and awareness, e.g., through distribution of information, establishing wastewater-related program, and community involvement in controlling and monitoring of wastewater management activities. Such activities are important to prevent failures due to theft and vandalism observed elsewhere in the operation of wastewater treatment plants (Tsagarakis et al., 2001). 5.4. Establishing regulations and enforcement Requirements and regulations for residential and commercial buildings for design and standard of on-site wastewater systems should be established, as well as guidelines of a standard system for commercial buildings (hotels, hospitals, shopping centers, and restaurants). Enforcement should be applied with sanctions to parties who disobey the regulations. Any party who produces wastewater must be held responsible for not discharging anything that will negatively impact the receiving water, and, if impacts occur, sanctions (administrative, fine, reestablishment or improvement, and punishment) should be imposed. 6. Conclusions In the present study the constraints and potentials for formulating and designing a wastewater management plan for the city of Manado are analysed. Constraints are formed by: (1) natural settings, which influence land use changes, (2) the rapid increase of population, (3) the frequency of low-income households, (4) the variety of wastewater sources, (5) the poor condition and capacity of wastewater disposal and treatment systems, (6) institutional arrangement of government, and (7) lack or inadequacy of local regulations and policies. Potentials include (1) good environmental awareness of the community, (2) government institutions at provincial and national levels, and (3) the established regulations and policy measures of Agenda 21. Considering these constraints and potentials, community involvement should be increased through an environmental education program. Also, wastewater management should be an integrated effort of all involved agencies at city, regency, provincial and national levels. Policies and regulations from Agenda 21 should be implemented at city level. Acknowledgments This paper is part of the first author’s doctoral dissertation research. The financial support of the Danish International Development Assistance (DANIDA) through the Asian Institute of Technology (AIT) and the Integrated Tropical Coastal Zone Management (ITCZM) Program is gratefully acknowledged. We would

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