Decentralized Domestic Wastewater Treatment in Asia Tetsuo Kuyama Manager (Water Resource Management) Natural Resource and Ecosystem Services Area Institute for Global Environment Strategies (IGES)
Sanitary Condition in Asian Countries Urban Area Rural Area Proportion of population using improved sanitary facilities 2
Change of Domestic Water Use in Asia Municipal Water Withdraw per person (m3/person/yr) Year Source: FAO, AQUASTAT Change of water withdrawal per person for domestic purpose 3
Impact of Domestic Wastewater on Water Environment 100% % of BOD Load 80% 60% 40% Others Industrial Domestic 20% 0% Japan [Tokyobay,Ise bay and Seto inland sea] (2009) Korea [Han River and Paldang reservoir/seoul] Indonesia [Brantas River Basin/East Java] (1994) County[area](Year) Phillippine (1998 2000) Vietnam [DongNai River/HCMC] (2005) COD BOD BOD BOD BOD BOD/COD Pollution Source by Sector in Selected Asian Countries/Areas 4
Impact of Grey Water on Water Environment BOD Pollution load (g/cap/day) 88 % 68 % BOD load from different source of domestic wastewater in Thailand and Japan 5
Methodology for Domestic Wastewater Treatment Centralized Treatment Wastewater collection and treatment system for more than two communities (sewerage treatment plant) Cluster Treatment Wastewater collection and treatment system for two or more households but less than an entire community (such as community based treatment plant) On site Treatment Treatment system to collect, treat and discharge domestic wastewater from individual households without the use of community wide sewers (such as septic tank, Johkasou) 6
Centralized Treatment Facility in Asian Countries Beijing (1 million m 3 /day : Activated Sludge) Kathmandu (16 thousands m 3 /day: Oxidation Ditch) Urumqi (10 thousands m 3 /day: Oxidation Ditch) Jakarta (45 thousands m 3 /day: Oxidation Pond) Suphan Buri (11 thousands m 3 /day: Stabilization pond) HCMC (30 thousands m3/day: Oxidation Pond) 7
Centralized Treatment Coverage in Asian Countries Sewerage Treatment Coverage (%) 100 80 60 40 20 0 Korea(2009) Japan(2010) China(2010)* Malaysia(2010)** Thailand(2008) Vietnam(2010) Philippine(2010) Less than 5 % Myanmmer(2010) Nepal(2010) Indonesia(2010) Cambodia(2010) Laos(2010) Sri Lanka(2010) Sewerage Treatment Coverage (Black Water and Grey Water) *Chinese data is only for urban area **Except in Saba hand Sawawak province Country(Year) Service coverage ratio of sewerage treatment in selected Asian countries 8
Challenge in Centralized Approach Source:Human Development Report 2006, UNDP Cost of different domestic wastewater treatment methods 9
Challenges in Centralized Approach Sewerage reatment Ratio(%) 100 90 80 70 60 50 40 30 20 10 0 Indonesia China Thailand Phillippine Malaysia Korea 0 10,000 20,000 30,000 40,000 GDP per Capita (USD) Japan *Coverage ratio of China is only for urban area Range of GOD per Capita in othe WEPA countries Relationship between sewerage treatment ratio and GDP per capita in selected Asian countries as of 2010(except for Korea (2009) and Thailand(2008)) 10
Possibility of Decentralized Domestic Wastewater Treatment in Asia Centralized Treatment Wastewater collection and treatment system for more than two communities (sewerage treatment plant) Cluster Treatment Wastewater collection and treatment system for two or more households but less than an entire community (such as community based treatment plant) On site Treatment Treatment system to collect, treat and discharge domestic wastewater from individual households without the use of community wide sewers (such as septic tank, Johkasou) 11
Diversity in Methodology of Decentralized Domestic Wastewater Treatment in Asia Examples of Decentralized Domestic Wastewater Treatment observed in Asian Countries On site Treatment Anaerobic Process Septic Tank(Thailand) Johkaso (Japan) Aerobic Process Cluster Treatment SANIMAS (Indonesia) Case 1 Case 2 Small scale of sewerage treatment plant (China) Case 3 Case 4 12
Case 1 : Onsite/Anaerobic Septic Tank (Thailand) 13
Septic Tank Coverage Population in selected Asian Countries Malaysia (2010) 20% Vietnam (2008) 41% Indonesia (2012) 53% Cambodia (2008) 43% Manila/Philippine (2010) 71% 14
Background(Thailand) 70 % of collected night soil is disposed to environment Sewer service area 30 % 70 % 21 % 79 % No sewer service area Septic Tank Septic Tank Wastewater treatment facility Night soil treatment facility Landfills, agricultural field, waterways Source: Dr. Suwanna (2012, WEPA international workshop, Cambodia) 15
Water Quality : Influent and Effluent of Septic Tank Source: Dulyakasem, S., et. al., 2013. Determinations of Blackwater characteristics and sludge accumulation rates in Decentralized Wastewater Treatment Systems (DEWATs) in Thailand 16
Removal Rate (BOD) of Septic Tank Influent BOD load 115g/Cap/Day Black Water 14 g Septic Tank BOD removal rate 52% for Black Water 6% for Black and Grey Water Effluent BOD load 108g/Cap/Day Grey Water 101 g Treatetd Water 17
Cost of Septic Tank in Thailand Cost of commercial septic tank and septage collection fee in Thailand Items Price of commercial septic tank for 5 persons Septage collection fee by Local Government Authorities (LGAs) First cubic meter desludging Subsequent cubic meter (less than half) (more than half) Cost 3,000 12,000 Baht (100 400 USD) 250 Baht/ m3 (8 USD/ m3) 150 Baht/ m3 (5 USD/m3) 250 Baht/ m3 (8 USD/ m3) Source: Dr. Suwanna (2012, WEPA international workshop, Cambodia) 18
Case 2 : Onsite/Aerobic Johkasou (Japan) 19
Population Coverage by Type of Domestic Wastewater Treatment in Japan Night soil collection Case 2 Johkaso (Japan) Onsite/Aerobic Sewerage treatment system (Centralized treatment) Johkasou 20
Treatment process for Johkasou Wastewater is treated biochemically by the catabolism of microorganisms such as bacteria and metazoan organism. Anaerobic filter contact aeration process is mainly used for Johkasou in Japan 21
The Quality of Effluent from Johkasou Number of Samples 0 100,000 200,000 300,000 400,000 BOD level of Effluent(mg/l) x 5 5<x 10 10<x 15 15<x 20 20<x 30 30<x 40 40<x 50 50<x 60 60<x 90 90<x 120 120<x 160 160<x 85 % <20mg/l (Effluent Standard) Results of Annual Inspection for Johkasou as of 2011 22
Effect of Environmental Improvement by Johkasou Influent BOD load Johkasou BOD removal rate Effluent BOD load 40g/Cap/Day 90% 4g/Cap/Day Grey Water 27 g Black Water 13 g Treated Water 23 23
Cost for Installation and Operation/Maintenance of Johkasou An Example of Installation and Maintenance Cost for a Johkasou (5PE: Population Equivalent) Items Cost (US$) Installation 9,061 Operation and Maintenance (Annual) 701 Maintenance 227 Desludging 280 Electricity 140 Inspection 54 Exchange rate: 1 USD 92.7JPY 24
Case 3: Cluster/Anaerobic SANIMAS (Indonesia) 25
Increase of SANIMAS Facilities in Indonesia SANIMAS: Community Based Sanitation Program 600 500 Number of Faciloties 400 300 200 100 0 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Year Source: PU Indonesia (2013) 26
Treatment Process for SANIMAS Anaerobic Baffled Bioreactor and Anaerobic Biofilter are widely used for SANIMAS in Indonesia Anaerobic Baffled Bioreactor 27
The Quality of Effluent from SANIMAS Number of Sample 0 20 40 60 80 100 BOD level of effluent (mg/l) x 5 5<x 10 10<x 15 15<x 20 20<x 30 30<x 40 40<x 50 50<x 75 75<x 100 100<x 120 120<x 160 160<x 95 % <100 mg/l (Effluent Standard) (37% <20mg/l) Results of Inspection for SANIMAS as of 2012 Source: MOE Indonesia 28
Cost for Installation and Operation/Maintenance of SANIMAS Installation Cost and Annual Fee for SANIMAS (200PE: Population Equivalent) Items Installation Annual Fee for SANIMAS User(per household) Cost 400,000,000Rp (40,680USD) 6.0 12.0 USD 29
Case 4 :Cluster/Aerobic Small Scale of Sewerage Treatment Plant (China) 30
Domestic Wastewater Treatment in Rural China City Town Villages Source: statics on construction in city, town and villages (2007) 31
Cooperation Project between Japan and China Harbin city, Heilongjiang province (1) Dongsheng Village, Nangang District Xinjiang (Weiwuer) autonomous region (1) Shuixigou town, Wulumuqi prefecture, Wulumuqi city Zhangjiakou City,Hebei Province (1) Saibei Administration District Project sites in 2008 Project sites in 2009 Project sites in 2010 Dali Baizu autonomous prefecture, Yunnan province (1) Xiangyangxi village, Wanqiao town, Dali city Taizhou city, Jiansu province (1) Zhaojia new village, Xinghua city (2) Dongbei village, Xinghua city Chongqing city (1) Baiyang town, Wanzhou district (2) Maguan town, Zhong prefecture 32
Concept of Applied Treatment Process Primary Treatment Secondary Treatment Tertiary Treatment sedimentation separation contact aeration Sludge Treatment (for Reuse) composting (drying) multi-soil layer treatment Constructed wetland Discharge/ Reuse 33
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BOD Level of Influent and Effluent Water BOD Reduction: 62 97 % BOD Reduction: 43 98 % mg/l 700 600 500 400 300 200 100 0 Sep Oct Nov Dec Jan Feb Mar Apr May Influent Effluent Standard (30 mg/l) mg/l 350 300 250 200 150 100 50 0 Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Influent Effluent Standard (30 mg/l) Maguan town (Chongqing city) Baiyang town(chongqing city) BOD Reduction: 64 95 % BOD Reduction: 66 97 % 80 60 Influent 80 60 Influent mg/l 40 20 Effluent mg/l 40 20 Effluent 0 Aug Sep Oct Nov Dec Jan Feb Mar Apr May Standard (20 mg/l) 0 Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Standard (20 mg/l) Zhaojia new village (Jiangsu province) Dongbei village (Jiangsu province ) 36
Cost for Installation and Operation/Maintenance Installation Cost and Annual Operational Cost for Constructed Facilities No Site Population Capacity (m3/day) Treatment process Construction Cost Operational Cost (Year) 1 Maguan town (Chongqing city) 6,000 500 Active sludge + Constructed Wetland 4.98 million CNY (805,000USD) 85,732 CNY (13,858USD) 2 Baiyang town (Chongqing city) 6,000 600 Contact Aeration+ Constructed Wetland 2.35 million CNY (380,000USD) 53,750CNY (8,688 USD) 3 Zhaojia new village (Jiangsu province) 750 150 Contact Aeration 1.61 million CNY (260,000USD) 35,925CNY (5,807USD) 4 Dongbei village (Jiangsu province ) 200 40 Contact Aeration 0.59 million CNY (95,000USD) 30,138CNY (4,871USD) 37
Summary 38
Effluent Quality/Reduction Rate and Cost of Different Decentralized Domestic Wastewater Treatment Methodologies Treatment Methodology Effluent Quality (BOD) BOD reduction Rate (%) Construction Cost (USD/population) Annual Operational Cost/Fee (USD/population) On-site treatment (Anaerobic) Septic Tank (Thailand) 658-1,157 6% (black water 52%) 20-40 - On-site treatment (Aerobic) Johkasou (Japan) Cluster treatment (Anaerobic) SANIMAS (Indonesia) - (<20mg/l: 85%) 1-264 (<20mg/l: 37%) 90% 1,812 140-203 1.5-3 Cluster treatment (Aerobic) Small Scale of Sewerage Treatment Plant (China) 1-33 (<20mg/l: 82%) 43-98% 63-475 1.4-24 39
Other factors to be considered Following factors should be considered for the installation of decentralized domestic wastewater treatment Required land area Detention time Lifetime of facility Optimum temperature Required skills for O&M Others 40
Conclusion Impact of Grey Water to the Water Environment should be paid more attention. Appropriate decentralized domestic wastewater treatment technology should be decided considering natural/socioeconomical condition and level of development at the site. How to maintain the decentralized facilities is also important issue for sustainable management of the decentralized domestic wastewater treatment system. 41
Water Environmental Partnership in Asia (WEPA) WEPA consists of partners in 13 Asian countries 1. Democratic Socialist Republic of Sri Lanka (Sri Lanka) 2. Federal Democratic Republic of Nepal (Nepal) 3. Japan (Japan) 4. Kingdom of Cambodia (Cambodia) 5. Kingdom of Thailand (Thailand) 6. Lao People's Democratic Republic (Lao PDR) 7. Malaysia (Malaysia) 8. People's Republic of China (China) 9. Republic of Indonesia (Indonesia) 10. Republic of Korea (Republic of Korea) 11. Republic of the Philippines (Philippines) 12. Socialist Republic of Viet Nam (Viet Nam) 13. Union of Myanmar (Myanmar) WEPA Database www. wepa db.net 42
Thank you for your participation 43