Technology and Management
situation of decentralized
domestic wastewaterin Vietnam
TRAN Hieu Nhue, Prof. Dr.
TRAN Thi Hien Hoa, Dr.,NGUYEN Viet Anh, Assoc. Prof. Dr.,
Institute of Environmental Science and Engineering (IESE),
National University of Civil Engineering (NUCE)

Contents• 1. Introduction• 2. Situation of urban and rural sanitation inVietnam• 3. Technical and Management aspects ofdecentralized sanitation– 3.1. On-site sanitation– 3.2. Decentralized wastewater treatment• 4. Opportunities and Challenges indecentralized wastewater management• 5. Recommendations and Conclusions

1. INTRODUCTION• Oct. 2013: 766 cities and towns, with 30% of total population• Nov, 1st 2013: 90 million people.
• Fast urbanization process
Urbanization process in Vietnam over last 25years and forecast to 2020
Number of urban

Urban population (million)

1000

50900

45800

40700

35600

30500

25400

20300

15200

10100

5001986 1990

1995 2000

2005
Year

2009 2010Urban population(million)/ Rate of urban
pop. of total pop. (%)

Number of urban

Rate of urban pop. of the total pop. (%)

2011 2020(Source: Tran Hieu Nhue et.al.,2011)

2. Situation of sanitation in Vietnam• Combined sewerage system• 32 cities have executed sewerage and sanitation
projects funded by ODA• Access to toilets: > 90%• 40 - 70% population have access to sanitation service(sewerage and drainage network)• Majority of existing sanitation works in urban areas is
septic tank: 80%• Only > 10% of urban wastewater is treated• 18 WWTPs only treat app. 345,000m3/d of total
3,080,000 m3/d domestic WW generated• Diversified technologies• Difficulties in O&M (cost recovery, skills, etc)

List of centralized WWTPs in Vietnamese cities

Sanitation status in Vietnam

Government policies– Over the last two decades: about USD 2 bio. forwater and sanitation infrastructure improvement.
– Great efforts are to be acknowledged:• projects and activities of DESA group, IESE,• projects of GTZ and KfW, other donors,• BORDA, etc.
– Effluent Standard for not connected to the sewers,
and small flows: QCVN 14:2008/BTNMT.

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Vietnamese National Code for wastewater
effluent quality QCVN 14:2008/BTNMTNo
1234567Parameters
pHBOD5 (20oC), mg/l
TSS, mg/l
NH4-N, mg/l
NO3-, mg/l
PO43-, mg/l
Total Coliforms,
MPN/100 mlColumn A(a) Column B(b)
5-9
5–930
50
50
100
5103050610
3,000

5,000(a) - Maximum allowable values for wastewater discharged to water

bodies serving domestic water supply purpose.
(b) - Maximum allowable values for wastewater discharged to water
bodies serving another purposes (irrigation, water transport, etc.).

93. Technical and Management aspects ofdecentralized sanitation

3.1. On-site sanitation• On-site dry sanitation– Dry eco-san toilet– VIP

Reuse of urine and compost• On-site wet sanitation– PF toilet + infiltration pit/trench– PF toilet + Anaerobic treatment: Biogas digester/Septic
tank/Improved septic tank
– Anaerobic treatment + subsurface filtration (Infiltration
trenches, sand filter, constructed wetlands)
10Dry ecosan toilet• No flushingwater.
Separating
faece and urine• To add lime orash• Diluting urine forirrigation• 6 – 12 months
compost fordisinfection
before fertilizer• Low-cost
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Pour flush toilet

Siphonfor odorcontrol

Pour flush toilet + septictank

12Baffled septic tank with anaerobic filter BASTAF(IESE – SANDEC, 1998 - 2007)

ST <BAST<

50 – 60%

70 – 80%STAF
80 – 85%•ST – Septic tank
•BAST – baffled septic tank
•STAF-septic tank with anaerobic filter•BASTAF – baffled septic tank with anaerobic filter.

<BASTAF (HRT = 48 h)
80 – 90% (COD, CODf, TSS)

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PRE-FABRICATED WASTEWATER TREATMENT SYSTEMSAFSB® and BASTAFAT®

3.2. Decentralized w/w treatment technologies
LocationTechnologies applied

Activated sludge process, MBR
Hospitals, hotels, apartments, Tricking filter, RBC
office buildings in the urban
Submerged aerated filter
centers(a)A2O Jokashou and otherpackaged pre-fabricated plants
Pig farms(a)Biogas digester
Vietnam Friendship Village in Combined sewerage andXuan Phuong commune, Tu
drainage with CSOs, BASTAF +Liem district, Hanoi (2008)(b) HF CW
Low-income residential area
Combined sewerage andin Vinh Yen town, Vinh Phucdrainage with CSOs, BASTAF(b)province (2007)•A2O – anaerobic – anoxic – oxic treatment process.
•ABR – anaerobic baffled reactor.
•BASTAF – baffled septic tank with anaerobic filter.
•CSO – combined sewerage with overflow chambers.
•HF CW – horizontal flow constructed wetland(a) – implemented by different service providers.
15(b) – by DESA team, IESE.
(c) – by BORDA Vietnam

Location
Technologies applied
Xuan Mai concrete factory
Combined sewerage andresidential quarter, Chuong Mydrainage with CSOs, BASTAF
district, Hanoi (2007) (b)Lai Xa village, Kim Chung
Combined sewerage andcommune, Hoai Duc district,drainage with CSOs, BASTAF
Hanoi (2006 – 2007) (b)+ HF CW
Ta Thanh Oai and Huu Hoa
Combined sewerage andcommunes, Thanh Tri district,drainage with CSOs, BASTAF(b)
Hanoi (2005)
Tam Da village, Tien Son district, Combined sewerage andBac Ninh province (2002) (b)drainage with CSOs, BASTAF•A2O – anaerobic – anoxic – oxic treatment process.
•ABR – anaerobic baffled reactor.
•BASTAF – baffled septic tank with anaerobic filter.
•CSO – combined sewerage with overflow chambers.
•HF CW – horizontal flow constructed wetland(a) – implemented by different service providers.
16(b) – by DESA team, IESE.
(c) – by BORDA Vietnam

DWWM in small towns and peri-urban areas

BASTAF

Lai Xa village, Hoai Duc,Hanoi

••
•
•

HF CW

(Fish) Pond

17Bac Ninh – living quarter

Bac Kan – small town

Type of sewerage and drainage system?
Coverage? HH connection?
Wastewater fee collection?
Investment?

4. Opportunities and Challenges
in decentralized wastewater
management
Financing mechanisms for sanitation projects• Work order for O&M: paid by city’s budget. Partof it: collected w/w fees
• Urban w/w fee: 10% surcharge to water bill. Hai
Phong city: 15%. Other cities are preparing toincrease.
• For not connected households: environmentalfee (10%). (Decree No. 67/2003 to be revised)Major challenges in sanitation projects• Lack of knowledge of decentralised options• Quality of design and construction,
associated with– consultants’ competency,– administrative appraisal procedures,• Low rate of household connection,• Financial sustainability,• Shortage of qualified work force and skills forO&M.
• Out-sourcing services are often not available
or not affordable in the area.
19• Technical aspects– There are still very few decentralized technicaloptions developed and applied.
– Systematic review has not been conducted:• DEWATS system performance, publicacceptance, etc.
• Balancing of investment, and O&M costs,
including required space, manpower, energyand chemicals.
– Collection of wastewater: little national andinternational experience in combined drains +septic tanks.
– Design guidelines are still lacking.
– etc…
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• Financial aspects– Wastewater fees is still very low in urban areas,and zero in rural areas (Decree 88…)
– Private sector is till not interested in this business.

• Social aspects– Traditional acceptance of untreated wastewaterdisposal by most of people.
– Wastewater reuse attitudes of the public andpolicy makers hinder the adoption of wastewater
treatment and safe reuse systems.
– The main challenge is to create informed demandfor improved sanitation.

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5. Conclusions andRecommendations• Sanitation improvement should startfrom household• Ecosan concept• Technical aspects• Wastewater management regulations• Sustainable sanitation model• Technical aspects– Combination of different options– Cost-benefit analysis of different sanitation options
should be developed.
– We need information of unit costs of different
sanitation options, in different local contexts24• Sustainable Sanitation Model

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Thank you very much foryour kind attentions !