SFD Promotion Initiative Danang Vietnam
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SFD Promotion Initiative Danang Vietnam Final Report This SFD Report was created through desk-based research by Sandec (the Department of Sanitation, Water and Solid Waste for Development) at Eawag (the Swiss Federal Institute of Aquatic Science and Technology) as part of the SFD Promotion Initiative. Date of production: 13/11/2015 Last update: 16/12/2015 Danang Executive Summary Produced by: Eawag/Sandec Vietnam SFD Report Danang, Vietnam, 2015 Produced by: Hidenori Harada, Eawag/Sandec Lars Schoebitz, Eawag/Sandec Linda Strande, Eawag/Sandec ©Copyright All SFD Promotion Initiative materials are freely available following the open-source concept for capacity development and non-profit use, so long as proper acknowledgement of the source is made when used. Users should always give credit in citations to the original author, source and copyright holder. This Executive Summary and SFD Report are available from: www.sfd.susana.org Last Update: 16/12/2015 I Danang Executive Summary Produced by: Eawag/Sandec Vietnam 1. The Diagram Note: Percentages do not add up to 100 due to rounding 2. Diagram information 2015). Danang is divided into two rural districts and six urban districts, and the urban districts The Shit Flow Diagram (SFD) was created accounts for 87.3% of the total city population through desk-based research by Sandec in 2013 (GSO 2015). Even among the urban (Sanitation, Water and Solid Waste for districts population densities vary, with some Development) of Eawag (the Swiss Federal areas being much denser. Institute of Aquatic Science and Technology) The topography of Danang is highly variable, Collaborating partners: as the north and northwest of the city are Kyoto University, Japan located on the south edge of the Truong Son The University of Danang, Vietnam Mountain Range, and the east faces the Danang University of Technology, Vietnam Pacific Ocean. The city has a tropical monsoon climate with two distinct seasons, the Status: typhoon/rainy season (September - March) Final SFD. Not yet reviewed by external and the dry season (April - August). Annual committee. average temperature and rainfall are 26oC and 2,505 mm, respectively (Danang City 2015). Date of production: Danang experiences flooding every few years. 13/11/2015 Hydrology issues include the tidal impact of the Pacific, and the Han River, which flows freely 3. General city information through central Danang (Opitz-Stapleton et al. Danang is located at the South Central Coast 2009) of Vietnam. It is the fourth most populated city in the country with approximately 1,007,400 Executive Summary inhabitants in 2014 (GSO 2015), and is a gateway of the East-West Economic Corridor running through Myanmar, Thailand, Laos, and Vietnam. The total land area of the city is 1,285 km2, including 65 km2 of residential area (GSO Last Update: 16/12/2015 II Danang Executive Summary Produced by: Eawag/Sandec Vietnam 4. Service delivery context approved four types of on-site sanitation facilities: double vault toilets, VIP toilets, pour- Policy flush toilets with a pit, and water flush toilets At the national level, the Orientations for with a septic tank. Also, the Vietnamese Development of Water Drainage in Vietnamese Building Code approved by the Decision on Urban Centers and Industrial Parks up to 2025 Promulgating the Building Code of Vietnam and a Vision Towards 2050 (No.1930.QD-TTg, (No. 682/1996/BXD-CSXD) mandates that all 2009) is the key policy regarding wastewater urban houses built since 1996 install a septic treatment. However, only 10% of urban tank. wastewater is treated in Vietnam (Pham & The treatment service standards are partly Kuyama 2013). The management of faecal regulated in the National Technical Regulation sludge from septic tanks is specifically noted in of Domestic Wastewater (QCVN 14:2008) and the Decree on Drainage, Sewerage and in the General Environmental Requirements for Wastewater Treatment (No.80/2014/ND-CP): Central Domestic Wastewater Treatment septic tanks shall be periodically emptied; Plants (TCVN7222:2002). The service emptying and transportation shall be done by standards for emptying and transport does not specialized vehicles and equipment; faecal exist (KII May 13, 2015; KII July 7, 2015). sludge shall be transported to approved sites; and the discharge of faecal sludge emptied 5. Service outcomes from septic tanks into drainage or the Thirty-eight (38%) of the excreta flow is environment is strictly prohibited. Notification classified as safely managed, and the that detail the decree are expected to be remaining 62% was classified as unsafely released. The National Strategy for Integrated management. The details are discussed along Management of Solid Waste up to 2025, with a the sanitation service chain below. Vision to 2050 (No.2149/2009/QD-TTg) also specify the target of faecal sludge collection Containment and treatment. Table 1 shows seven types of containment The city declared the Wastewater systems are used in the city (NSC 2010; Management Strategy of Da Nang City Harada et al. 2011; Pham et al. 2012; Tran Towards 2020 and Orientations Towards 2040 2012; Pham 2014). There is no user interface (8438/2010/QD-UBND) (GIZ 2014; DOT 2010; which drains toilet wastes directly to combined CDIA 2012). However, the concrete contents sewer or open drain. of these regulations could not be found during Of the excreta in the city, 59% (F2) are safely the research for this study. contained by septic tanks connected to soak Service provision pits without significant risk from groundwater pollution (47%), and septic tanks connected to According to the national orientations above combined sewers (13%). On the other hand, (No.1930/2009/QD-TTg), Danang has a target 41% (F10) of the excreta was not safely to achieve 70-80% of household wastewater managed at the containment, which is mainly collection and treatment by 2015. In addition, caused by septic tanks connected to soak pits the city has its own target to up to 2020: 50% at significant risk from groundwater pollution of households and 100% of all other (31%). Based on the groundwater pollution risk wastewater producers are to be connected to decision matrix of the SFD calculation tool, treatment plants (No.8438/2010/QD-UBND) septic tanks with soak pits in the area with (GIZ 2014; DOT 2010). However, only 47% of access to the public water supply networks urban wastewater is collected in Danang (NSC was regarded as safely contained, whereas 2012). that without access was regarded as unsafely According to the national strategy above contained. (No.2149/2009/QD-TTg), the targets for the Table 1: Sanitation containment systems in Danang collection and treatment of faecal sludge up to environmental standards in Danang were set Description of systems (% coverage in the city) at 30%, 50% and 100% for 2015, 2020 and 2025, respectively. The city’s own target from Septic tank connected to a centralised combined the aspect of solid waste management could sewer (12.6%) not be found during the research for this study. Septic tank connected to a soak pit (46.7%) Service Standards Septic tank connected to a soak pit at significant risk The Decision on the Issuance of Sector from groundwater pollution (31.3%) Standard: Sanitation Standard for all Kinds of Toilets (Lavatories) (No.08/2005/QD-BYT) Last Update: 16/12/2015 II Danang Executive Summary Produced by: Eawag/Sandec Vietnam Septic tank connected to an open drain (3.1%) Lined tank with impermeable walls and open bottom at significant risk from groundwater pollution (2.5%) Lined pit with semi-permeable walls and open bottom at significant risk from groundwater pollution (2.5%) Unlined pit at significant risk from groundwater pollution (1.3%) Emptying Figure 1: A faecal sludge treatment plant of the Khanh Son Landfill (Source: Hidenori Harada/Kyoto Univ. 2009) There are two types of emptying service the average septic tank volume (3.62 m3) providers: a public company, called the (Pham et al. 2012), transported amount of the Danang Urban Environment Company Khanh Son Landfill in 2011 (10,687 tons). Of (URENCO), and private emptying service the emptied faecal sludge, 23.8% was providers. Both types of providers employ transported to the landfill, while the remainder motorized emptying. was not. In reality, septic tanks are not emptied Treatment regularly, but only when a tank malfunctions (Pham et al. 2012). However, according to key Faecal sludge is treated at a faecal sludge informant interviews (KII Jul.7, 2015; KII Aug. treatment plant of the Khanh Son Landfill 14, 2015), almost no households abandon (Fig.1). The plant employs a sedimentation septic tanks after they malfunction but have process. The sediment is landfilled, whereas them emptied so they can continue using supernatant is treated together by a leachate them. Therefore, this study assumed that treatment process (DUEC 2006). Wastewater 100% of the septic tanks are emptied in 9.5 is treated at four centralized treatment plants year intervals (Pham et al. 2012). Since employing anaerobic lagoons (NSC 2012). information of emptying services for other This study assumed that the excreta containment systems exist, this study assumed transported to these plants are adequately that 50% of the containment systems that are treated. not septic tanks are emptied. The total treated proportion was 15%, Forty-seven percent (48%, F3) of the excreta composed of 11% for faecal sludge (F5) and was emptied based on an important 4% for wastewater (W5a). Actually, 37% of the assumption: the proportion of faecal sludge in faecal sludge (F11) is not transported to a each septic tank (not effluent, supernatant, or treatment plant, resulting in no treatment of this infiltrate) is 50%, the default value of SFD faecal sludge. This is the largest flow of unsafe calculation tool, and only the 50% was counted management. Good transportation of the to be emptied.