This presentation helped the planning agency to understand the options available for a rational implementation schedule, considering costs and benefits.

1. MUNICIPAL WASTEWATER
Pre-Feasibility Studies in Industrial Waste Water Management
and Drainage Systems
Cities Development Initiative for Asia (CDIA)
Da Nang
Final Report – Presentation for Task Force on Wednesday 30 May 2012

2. DA NANG CITY –WASTEWATER SYSTEM
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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Schematic
Layout
Existing
Situation
(Source: Grontmij &
Carl Bro 2009)

3. DA NANG CITY –WASTEWATER SYSTEM
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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Schematic
Layout
Plan
(Source: Grontmij &
Carl Bro 2009 –
recommended
option)

4. THE TEN SERVICE ZONES FOR WASTEWATER COLLECTION
WWTP SON TRA WWTP NGU HANH SON
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5. PRIORITY PROJECTS
 Optional criteria for priority ranking:
 Low-income areas with dense population
 Resettlement areas
 New development areas
 Planned development areas
 Tourism areas
 Technical and financial rationale
 Other basis, to be identified
 Da Nang directions on priority ranking:
 Priority is for the coastal service zones draining to the eastern
beaches. This is a main centre of the tourism economy in Da Nang.
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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6. THE TEN SERVICE ZONES
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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 Idea for sequencing of works

7. THE TEN SERVICE ZONES - PRIORITY SEQUENCING
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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8. COST ESTIMATION – BASIC PREMISES
 Wastewater systems should be planned/designed with the
capacity required in the year 2020.
 For planning purposes, district population numbers for
2020, as specified by DPI, should be used.
 In 2020, the targeted connection rate for households
should be 50%, and for all other wastewater producers
100%, as per the Da Nang Wastewater Strategy of 2010.
 Should use the Da Nang Municipal Infrastructure Map
(digital).
 The study’s calculations should comply with the official technical design
criteria for the sector.
 Cost estimation should be made according to the guidelines for public
investment projects.
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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9. DA NANG WASTEWATER MANAGEMENT STRATEGY
 Wastewater Management Strategy to the year 2020 (8438/QD-UBND,
03/11/2010)
 Sets definite targets to be achieved by 2015 and 2020
 Gives orientation for further development until 2030 and 2040
 Attached: “Wastewater System Strategy” (July 2010)
 Three strategy targets important for our study:
 capacities of WWTPs Son Tra, Ngu Hanh Son, Hoa Xuan
 percentage of households to be connected to the system
 development of a separate wastewater system, with priority for
 new residential areas, tourist areas, and coastal areas
 Districts Son Tra and Ngu Hanh Son:
 Coastal area – Beaches a core asset for tourism - New residential areas
 Focus of study:
 To separate wastewater system from storm water system
 To substantially increase number of households connected to system
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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10. COST ESTIMATE – BASIC SCENARIO
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11. ALTERNATIVE SCENARIO FOR INITIAL INVESTMENT
 Basic Scenario – Initial Investment cost 100%
 Full coverage of the service zone by tertiary & secondary networks
 50% connection rate (50% of expected number of wastewater producers
in 2020)
 Scenario A – Initial investment cost down to 58%
 Selected coverage of the service zone by tertiary & secondary networks,
namely just enough for achieving …
 50% connection rate (50% of expected number of wastewater producers
in 2020)
 Scenario B – Initial investment cost up to 101%
 Same as Basic Scenario, but tertiary and secondary networks use a
higher percentage of larger diameter pipes
 Scenario AB - Initial investment cost down to 59%
 Same as Scenario A, but tertiary and secondary networks use a higher
percentage of larger diameter pipes
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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12. ALTERNATIVE SCENARIO FOR INITIAL INVESTMENT
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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13. RECOMMENDED SCENARIO & FURTHER REFINEMENT
 Priority 1&2: Service zones C-ST1 and C-NHS1, C-ST2 and C-NHS2
 Rationale:
 Most important and urgent is to stop pollution of beaches and sea by wastewater spills
 Therefore, have to connect all wastewater producers to a dedicated wastewater collection system at once
 Scenario: Adopt B
 Refinement: connect all wastewater producers at extra cost of about 3%
 Priority 3&4: Service zones R-ST1 and R-NHS1, R-ST2 and R-NHS2
 Rationale:
 Important is to reduce the pollution of the river by wastewater spills
 Urgency not very high: connection rate 50% by 2020 is acceptable
 Should be selective in initial coverage
 Install extra capacity into tertiary and secondary networks to accommodate increasing connection rate
 Scenario: Adopt AB
 Refinement: none
 Priority 5: Service zones C/R-NHS3 and D-NHS1
 Rationale:
 Residential development still at initial stage and wastewater production is at a low level
 Only connect areas with high wastewater production level: housing complexes, tourist resorts
 Install extra capacity into tertiary and secondary networks to accommodate increasing connection rate
 Scenario: Adopt AB
 Refinement: Reduce initial investment to 1/3 of cost of AB
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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14. COST ESTIMATE – ALTERNATIVE SCENARIO
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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15. TIME SCHEDULE
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16. FURTHER STUDY
 Verify population growth estimates
 What is the maximum population density? For example, CIPR (2010)
mentions densities varying between 1,674 persons/km2 in Lien Chieu to
18,380 persons/km2 in Thanh Khe.
 Consider possible risks/issues and identify solutions
 Implications of saline environment
 Unexploded ordinance and toxic materials
 Need for maintaining access possibilities to premises
 Recommend mitigation measures for current situation
 Pump all water to the river?
 Discharge to the sea, through a long pipe?
 Consider technical and investment options
 Formulate priority projects
Municipal Wastewater – Final Report – Presentation on 30/05/2012
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17. THE END
Thank you
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