DECENTRALIZED WASTEWATERMANAGEMENT (DWWM) IN VIETNAM
Hanoi, November 2022

Prof. Dr. Nguyen Viet - Anh

1Vice President, Vietnam Association of Water Supply and Sewerage (VWSA)
Director, Institute of Environmental Science and Engineering (IESE),Hanoi University of Civil Engineering (HUCE). Email: anhnv@huce.edu.vn

CONTENT• DWWM models• Design – Build – Operation (D-B-O) challenges• Fecal sludge management• Performance test
• Recommendations: solutions for improvement

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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Recent situation of wastewater treatment in Vietnam
Centralized
Wastewater
Treatment system(Ex: Sewer system)

Middle scale orcluster typewastewater
treatment system

Decentralized wastewater
treatment system(Ex: Septic tank, johkasou,
pit latrine)

Without any
wastewater
treatment- Sewered + directdischarge- Non-sewered
areas

Definition of eachtreatment system
in your country- HHs + Collection + WWTP
for city scale serving basin
or sub-basin catchment
area- Septic tanks at HHs as
preliminary treatment are
in most cases- Serving towns, townlets,development areas withsewers- Non-sewered areas, or shortdistance sewer lines (resorts,individual apartments, shops,restaurants, hospitals, factories,etc)

Installed plant
number- 70 WWTPs in >40 cities,
with design capacity 1.4
mio. m3/day- 80 WWTPs are underdesign or construction,with design capacity 1.6
mio. m3/day- 10% of 4,000 urban
development areas = 400
WWT stations (WWTS) inpaper, 50% of them arefunctioning in realty = 200
WWTS: Phu My Hung,
Ecopark, Royal city, Times
city, Ocean park, Dang Xa,
etc

Number ofPopulation using
each wastewater
treatment systems- 17% of urban population =6 million persons- 200 WWTS x 50% of
design capacity x 500
m3/d or 3,000 persons =30,000 persons- Handcraft villages: just afew

- Country: 90% of 13,600 medicalpoints (hospitals, clinics, etc) =12,250 WWTS, among which 35%
are in good operation condition.
- 1,000 WWTS in factories- 200 WWTS in restaurants, shops,resorts- 1,000 WWTS in hotels- Total: 14,500 WWTS
- Besides: 25,000 systems with
Septic tanks only
- Livestock farms: 400,000 m3/d x
30% with biogas digester*Reference: figures are calculated by author based on various sources
Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

- Hospitals: 1,012,500 persons areserved- Hotels, resorts: 1,260,000 p.
served- Factories: 300,000 p.

Classification of DWWM models• Group 1: On-site sanitation systems– 1a. Low-cost on-site sanitation systems– 1b. Mechanized on-site sanitation systems• Group 2: Cluster DWWM systems (with wastewater collectionnetwork)– 2a. Low-cost cluster wastewater treatment systems– 2b. Mechanized cluster wastewater treatment systems• Different ownership, sources of funding, modes ofmanagement, etc.

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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Group 1a, Low-cost on-site sanitation systems

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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Group 1b, Mechanized on-site sanitation systems

BASTAFAT-F FOR 12 HIGH-CLASSVILLAS AT NCC MY DINH, HANOIBASTAFAT-F FOR CAT BA ISLAND,HAI PHONG

UV MODULE FOR DISINFECTION

SOLAR PANEL AND REMOTE(ON-LINE) CONTROL

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

JAPANESE JOHKASOU
6Group 2, Cluster systems
for group of householdsDrainage and sewerage network:- Household connection- Combined sewerage system- Separate sewerage system- Stormwater overflows

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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Group 2a, Low-cost systems

BASTAF for 160 households

BASTAF for 400 HHs, Xuan Mai townlet,
Chuong My, HN
Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

BASTAF + CW for 2,600 HHs,
Cho Moi townlet, Bac Kan

BASTAF for handcraft villages(food processing, livestock
breeding, …)

BASTAF for 100 HHs in Lim
townlet, Bac Ninh prov.

BASTAF + CW + Pond, Q = 100 m3/day,Vietnam Friendship Village, Hanoi
Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

Group 2b, Mechanized systems
PACKAGED WWTS AFSB-C

PACKAGED WWTS AFSB-F

AFSB-F at Vicostone Co.
Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

AFSB-F for Residential – Office Complex
12 Thuy Khue, Hanoi

10Group 2b, Mechanized systems

Pacific building, Hanoi
35 FRP tanks

PVN bldg, Hanoi

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

Sofitel Plaza, Hanoi

VCB bldg, Hanoi

Tam Chuc Temple, Ha Nam(Fudeso Co.)
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Challenges at Group 1, Low-cost on-site
sanitation systems
Design:• No official DesignStandard (MOH:Manual only)• Volume if not enough?
• No water proof?
• Some use housefoundation to maketank wall
• “Not allowed”
Infiltration chamber(soak pit)

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

Build:• No water proof• No access for checkand desludging• No ventilation• Misconnection (inlet,outlet, inside the tank)

Operation:• Septic tank is aproperty of household• No desludging unlessclogging• Sludge management is
not controlled• Miss-use: hazardous
waste

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Challenges at Group 1b, Mechanized on-site
sanitation systems
Design:• No official DesignStandard• No specific requirement
on technology andproduct certification, sothat everybody does indifferent ways with out
control on materials,equipment, technology• Problem in effluent
standard• Manufacturers are trying
to reduce costs byminimizing dimensions,simplifying equipment,materials

Build:• Floating• No requirements on
loading, floating
resistance, sand backfill, anchoring, …
• No requirements ontransportation,installation, testing,comisisoning,evaluation…

Operation:• Treatment tank is aproperty of household• No desludging unlessclogging• Sludge management isnot controlled• Miss-use: hazardous
waste

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Nguyen Viet Anh, IESE: DWWM

Challenges at Group 2, Cluster DWWS.
- Wastewater collection network
Design:• Connection is not aconcern of many
wastewater projects• Wrong selection ofcollection network type
• Lack of low-cost
sewerage solutions• Lack of integration withdrainage system

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

Build:• Quality of construction
works• Misconnection(rainwater andwastewater, household
connection, manhole,reverse flow, etc)

Operation:• Solids clogging• No fund for O&M• No clear solution for
dredged sludge
treatment/ disposal• Poor public
involvement

14Challenges at Group 2a, Cluster DWWS.
- Low-cost wastewater treatment systems
Design:• Lack of DesignStandard• Vietnamese standard
QCVN 14:2008/BTNMT,N, Coliforms: notachievable.
• Lack of adequate HHconnection andwastewater collection
components

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

Build:• Quality of construction
works• Planning and phasing• Start up difficulties

Operation:• Solids clogging• Hydraulic loads• No fund for O&M• No clear solution for
dredged sludge
treatment and disposal• Limited capacity ofoperators

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Challenges at Group 2b,
Mechanized wastewater treatment systems
Design:• Lack of Design Standard• QCVN 14:2008, N,
Coliforms: not achievable.
• Lack of adequate
wastewater collection
component• Double investment inurban areas• Too shallow: limited
aeration and settlingefficiency• Limited access, especiallyfor underground tanks

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

Build:• “Small” thinking, notadequate attention forQA• Quality of construction
works: leaking, sinking,etc.
• FRP tanks: very different
quality, not certified• Start up• Media wash-out

Operation:• Solids clogging• No fund for O&M• Smell control• C/N ratio is to low• No professional O&M
team16QCVN 14:2008/BTNMTNoParameters

Column A(a)Column B(b)

1pH

5-9

5–9

2

BOD5 (20oC), mg/l30

50

3TSS, mg/l

50

100

4NH4-N, mg/l

5105NO3-, mg/l [NO3-N ???] *30506PO43-, mg/l [PO4-P ???] **6107Total Coliforms, MPN/100 ml

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, watertransport, etc.).

*, ** - Different values in MONRE publication, hard copy, and web-site - QCVN 40:2011/BTNMT: Column A: TN = 20 mg/L; Column B: TN = 40 mg/L.
Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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Study on wastewater characterization
2021 - 2022
JCES and IESE
Objectives• To find characterization of domestic wastewater for PE
calculation basis• To update design standard TCVN 7957-2008 (MOC)
Targets:• Individual houses• Apartment, dormitory• Public buildings: office, school

Methods:• Composite sampling• Water consumption, Nutrients regime, Water usage• Temperature, pH, BOD, COD, TS, TN, TP
Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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Study on wastewater characterization:
Apartments
JCES and IESE

Pollution loads, with actual number of inhabitants

Effluent
STToilet use

127 ~ 177 L/cap.day
Adj. Black + Adj. Greywaterload:
COD: 44.8 (19.9 ÷ 90.1) g/cap.day
BOD5: 30.1 (13.8÷ 56.2) g/cap.day
T-N: 8.5 (3.0 ÷ 20.8) g/cap.day
T-P: 0.8 (0.4 ÷ 1.6) g/cap.day
TSS: 14.0 (4.0 ÷ 25.2) g/cap.day

Adj. Blackwater load:Settled blackwater load:

COD: 14.6(8.0 ÷ 24.3) g/cap.day
BOD5: 9.9 (5.5 ÷ 16.8) g/cap.day
T-N: 6.6 (2.3 ÷ 16.3) g/cap.day
T-P: 0.4 (0.2 ÷ 0.9) g/cap.day
TSS: 5.8 (1.8 ÷ 9.4) g/cap.day

COD: 8.9(4.9 ÷ 14.8) g/cap.day
BOD5: 5.6 (3.1 ÷ 9.6) g/cap.day
T-N:5.2 (1.8 ÷ 13.0) g/cap.day
T-P: 0.3 (0.2 ÷ 0.6) g/cap.day
TSS: 3.3 (1.1 ÷ 5.4) g/cap.day

Other uses

Laundry; Bathing;
Kitchen; Washing;etc.

Greywater
Greywater load:
COD: 30.2 (11.9 ÷ 65.9) g/cap.day
BOD5: 20.2 (8.3 ÷ 39.4) g/cap.day
T-N: 1.9 (0.7 ÷ 4.2) g/cap.day
T-P: 0.4 (0.2 ÷ 0.7) g/cap.day
TSS: 8.2 (2.6 ÷ 15.8) g/cap.day

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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Faecal Sludge Management••••••••

One of key components of DWWM
Poor management practice in mostplaces
Already mentioned in Decree
80/2014 and some provincial
regulations
QCVN 50-2013: HMs in sludge
10TCN 526-2002: Compostingfertilizer made from domestic solid
waste
Circular 41/2014/TT-BNNPTN on
fertilizer management
Law of Environment 2020
Resource recovery from sludge ispotential, but sludge reuse Guidanceis not yet available.

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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FSM PROJECT IN BEN TRE CITY
(1) Stakeholders involvement: Ben Tre city authority, Public Utility URENCO, Private
firms, Women’s Union (to work with Households)(2) Co-funding (BMGF through EMWF + local budget)(3) FS Treatment Station: Settling + Drying Bed; Leachate Treatment(4) Legal Framework Setting up: City’s FSM Regulation (emptying, transport,treatment, disposal), Cost structure (released 04.2022)

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE21PERFORMANCE TESTACTIVITIES:• Test on tank and tank materials• Test on effluent quality• Test on sludge accumulation, characteristics, and treatment
ISSUES TO BE ADDRESSED:• Testing site
• Testing time
• Testing conditions• Certified laboratories• “Pass” condition• Certification
Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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PERFORMANCE TEST
• Test on tank and tank materials– Product sample– At Quatest Labs (I, II, III)– At Quatest-cooperated Labs

– Materials test: tensile and tear strength, durability against
UV and corrosion– Tank test: water proof or tightness, hydraulic pressure andtop loading

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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PERFORMANCE TEST
• Test on effluent quality- On-site, or at selected wastewater treatment station as wastewater
source (to run experiment with product sample)- By VLAS and VIMCERT Certified Labs
- Over 4-6 months including winter time (coldest months)- Operation with at least 50% design capacity- Parameters in QCVN 14:2008/BTNMT: pH, BOD, TSS, NH4, NO3, PO4,Coliforms- Other parameters recommended: Temperature, COD, TN, TP.
- “Passed”: sample /week, 90% samples passed (recommended).

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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PERFORMANCE TEST•-Test on sludge accumulation, characteristics, and treatment
By operators or users
Sludge accumulation over the time (L/year)
Desludging interval (year)
Characteristics (recommended): temperature, pH, COD, BOD,TS, VS, TN, TP, Coliforms, Helminth eggs
Collection and transportation method
Treatment method
Disposal/reuse method
Hygienic and social acceptance monitoring at disposal siteProf. Dr. Nguyen Viet -Anh, IESE, HUCE

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Cost
Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

Treatment efficiency

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DWWM: related activities
Manufacturing
Design assessment and appraisal
Design and Build
Accessories supply: Air blower, pump, chemicals, media,
piping, bio-additives…
Planning; design standard, effluent code; construction
permit; discharge license; monitoring of water, air quality
Operation service
Maintenance service
Sludge emptying, transportation, treatment services
Network service (in case of online solution)
Training for design, build, operation and maintenanceProf. Dr. Nguyen Viet -Anh, IESE, HUCE

Advertisement, marketing, communication

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RECOMMENDATIONS:SOLUTIONS FOR IMPROVEMENT• Early decision making, integration of DWWM options into urban planning• Design standards are to be issued• Effluent standards are to be reviewed, especially on N, and pathogens
removal in DWWM systems, and to avoid double investment• Testing and Certification for technology, equipment, operation of w/w
systems, sludge management services is needed• Household connection should be compulsory. All components should beconsidered in a whole chain: HH facilities – collection network –wastewater treatment – disposal or reuse• Professional O&M service providers are needed, on-site or out-sourced.
Branch of provincial sewerage and drainage company is one amongoptions• Promotion center(s) with strong networking is needed

Prof. Dr. Nguyen Viet -Anh, IESE, HUCE

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THANK YOU VERY MUCH
FOR YOUR ATTENTION !

Prof. Dr. Nguyen Viet Anh
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Vice President, Vietnam Association of Water Supply and Sewerage (VWSA)
Director, Institute of Environmental Science and Engineering (IESE),Hanoi University of Civil Engineering. Email: anhnv@huce.edu.vn