The 18th WEPA​ Annual Meeting

Progress Report
WEPA Action Program in Lao PDR
Sengkeo Tasaketh1, Phengxay Deevanhxay2
1)Department of Natural Resources and Environment Inspection,

Ministry of Natural Resources and Environment2)Department of Chemistry, Faculty of Natural Sciences,
National University of Laos
8 February 2023

1

Contents
1. Background
2. Key Challenge
3. Objectives and Expected outcome of WEPA program in
Lao PDR
4. Activities in 2022-2023
5. Preliminary result of survey on water quality in publiccanals and existing decentralized wastewater treatment
facilities
6. Summary

2

Background-Vision, strategy and development plan3

• The vision 2030 aims to reach the status of an upper-middle-income
country with a green growth orientation by 2030.
• 10-Year Socio-Economic Development Strategy (2016–2025)• 9th National Socio-Economic Development Plan NSEDP (2021-2025)• The Natural Resources and Environment Sector Vision (NRESV) towards
2030 and Ten-Year Strategy (2016–2025)• Vision toward 2030: Make Lao PDR Green, Clean and Beautiful, basedon Green Economic Growth, to ensure Sustainable Resilient
Development and Climate Change Adaptation• Vision to 2035, and 9 year strategy on development of water supply andsanitation sector (2022-2030)• The overall goal of the strategy: Make all urban population can access to watersupply and sanitation that has been managed safely with satisfactory andreasonable price.

Background - Water quality in urban cities

4• Water quality in urban cities is getting deteriorated due to thedischarged wastewater from household, restaurant and commercial
facilities without proper treatment.
• Water color is quite dark due to the domestic wastewater and there
are many plants, especially Water Hyacinth in the canals.
• The organic pollutant was reported to be out of range of the National
Environmental Standard.

Hongxeng canal in Vientiane capital

5

Background-Present domestic wastewater treatment system• Majority of households have a pour flush latrine or dry pit latrine toeliminate black water and soak pit to eliminate grey water.
• Latrine with septic tanks have been widely used in urban area.

Pit latrine

Ventilated improved
pit latrine

Pour flush toilet

photos of Pour-flush toilet Source: Water and Sanitation Program (2016)

Septic tank toilet with soakaway

Plastic septic tank (HDPE) 0.8-2 m3

6

Background- Some decentralized wastewater treatment facilities• Approximately 29 decentralized wastewater treatment facilities were installed in 9
provinces during 2009-2020• Most of them are anaerobic treatment systems• There are some anaerobic and aerobic system (Johkasou) recently.
• Treatment capacity: 1-200 m3/day
Number of facilities

40
30
20

10
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2020
Year
Numbers of decentralized wastewater treatment system in Laos

Key Challenges
1. Lack of information on wastewater quality and performance of existing
decentralized wastewater treatment facilities
2. Lack of technical guideline for septic tank and decentralized wastewater
treatment
3. Lack of monitoring and maintenance of wastewater treatment facilities
4. Need sharing information and enhance collaboration between relevant
stakeholders on wastewater management
5. Limited number of staff and capacity of stakeholders on enforcement ofregulation and implementation
6. Institutional framework and financial mechanism for wastewater
management is in development stage
7. Limited financial support such as funding for capital investment,
operation and maintenance
8. Awareness of people on water quality is not highFind the way how to improve wastewater management system in Lao PDR.

7WEPA program in Lao PDR
Objectives of WEPA program in Lao PDR:
The main objective of the action program is to provide scientific basis
for improvement of wastewater management system and strengthen
the capacity of relevant stakeholders for water environment
improvement.
The specific objectives are:
1. To identify legal, institutional, financial, technical issues for improving domestic
wastewater management systems in Lao PDR
2. To study the domestic wastewater quality in public canals in 3 cities andperformance of some decentralized wastewater treatment facilities in Lao PDR.
3. To develop “training material for maintenance and operation of septic tank anddecentralized waste water treatment facilities“ , which will be used for drafting
the technical guidelines.
4. To strengthen the capacity of relevant stakeholders for maintenance andoperation of septic tank and decentralized waste water treatment facilities.

8

WEPA program in Lao PDR
Expected Outcomes• Understand the current institutional frame work of wastewater
management in Lao PDR (2022-2023)• Obtain scientific data on wastewater quality and current
performance of decentralized waste water treatment facilities in 3
cities of Laos (2022-2023)• Provide “Training material for maintenance and operation of septictank and decentralized waste water treatment facilities” , and draftof technical guidelines (2023-2024)• Enhance technical capacity of relevant stakeholders for a better
domestic wastewater management (2022-2024)

9

1) Literature review, collect information and site visit

Meeting at NREI，MONRE

Meeting at Department of Water Supply, Ministryof Public Work and Transportation

10

Visited fecal sludge treatment plant, Vientiane capital

Meeting at Urban Service Office at Luang Prabang
and other relevant organizations

112) Field survey
1. Conducted field survey• Interviewed decentralized wastewater treatment
facilities’ operators• Collected previous data and drawing of facilities• Conducted water quality measurement andSampling• Analyzed in the Laboratory• Period ( November 2022 – January 2023)

PlacesPublicCanal

BORDA
DEWATS

JohkasouSepticTank

Vientiane Capital

1 (2)

3 (7)

1 (2)

3 (6)

24 Nov 2022

Luang Prabang

1 (3)

1 (2)

1 (2)

30 Dec 2022

Khammouane

1 (4)

Note:
• Number in parenthesis () is number of samples• Mainly take samples at inlet and outlet of facilities

Sampling Date

17 Jan 2023

2) Field survey of decentralized wastewater treatment systems12

Field survey team comprise of• Officers from Department of Natural Resources and Environment Inspection, MONRE• Lecturers and students from Department of Chemistry, Faculty of Natural Sciences, NUOL

2) Field survey of decentralized wastewater treatment systems

132) Field survey of decentralized wastewater treatment systems

Field survey at Theun Hin Boun Power Company (THCP)’s camp

Field survey at decentralized wastewater treatment systems and Septic tank143) Organized Consultation Meeting (3 Feb 2023)

 7 topics were presented and shared in
Consultation meeting

Study tour at Johkasou facilities at
Wattay International Airport

15

16

Field survey- Sampling points in a canal in Vientiane Capital

Upper stream (near Sanjiang Shopping Mall)

Lower stream (near Phonekheng intersection)

17

Luang phrabang city

Upper stream (Pongkham Village)

Natural treatment pond
(Mano Village)
Down stream (Phonepheng Village) Middle stream (Mano Village)

Information of target decentralized wastewater treatment facilities

18

Treatment
type

Wastewater
Type

DesignTreatment
capacity(m³/day)

1 Thongkhankahm Village

Anaerobic(CBS)

Black + Grey(community)

11.2

146

2010

Vientiane Capital

2 Khua Luang Temple

Anaerobic
CBS)

Black

26

455

2012

Vientiane Capital

National Academy for
3 Politics and Public
Administration (NAPPA)

Anaerobic(RESan)Black + Grey

80 x 2

1600

2014

Vientiane CapitalNight market in Luang
Prabang

Anaerobic(RESan)Black + Grey

5

-

2017

Luang Prabang
province

Anaerobic +Planted gravel
Black + Grey
Theun Hin Boun Power
Filter+5Company Camp
Aeration +Disinfection(SBS-Lite)

70

700

2012

Khammouane
Province

6 Septic Tank at Temple

Anaerobic

Black

1

7

2018

Luang Prabang
province

Wattay International
7 Airport, International
Terminal

Aerobic(Johkasou)

Black + Grey

200

-

2018

Vientiane CapitalNo.

4

Location

Number of Operation
users
year

Provinces

Example of layout of decentralized waste water treatment

19

Source: BORDA Lao

Decentralized waste water treatment facilities

20Facilities maintenance related findings

21

Soil got into frame, made it difficult
to open the manhole cover

Metal frame of manhole cover got
erosion, made it difficult to open
the manhole for maintenance
Holders got erosion
and broken

Facilities maintenance related findings
Lot of scum layer at
the sedimentationchambers, notregularly remove

Garbage, plastic in thesedimentation chamber,not regularly maintenance

22

23

Public canal water quality
No.
1
2

3

Locations

CanalVientiane

Sampling
PointsUp stream

Down stream
Up stream
Canal-Luang Middle stream
Prabang
Down stream
National Surface Water
Standard Catgory 4

Temp.
C

pH

EC
uS/cm

DO
mg/L

TDS
ppm

TSS
mg/L

28.0

6.8

526

5.4

264

46.0

101

27.8

7.0

853

4.7

426

22.8
22.3
21.4

7.5
8.0
7.6

700
696
730

4.3
7.0
4.5

350
348
365

20.0
19
23
3.5

38
76
72
52

-

5-9

≦4000

>2

-

≦60

COD-Cr BOD5
mg/L
mg/L

10-12

T-P
mg/L

T-N
mg/L

TKN
mg/L

NO3 -N
mg/L

32

1.6

11.6

15.7

2.3

19
35
20
20

0.7
0.9
1.0
1.0

3.7

4.8
4.8
5.0

2.2
9.5
10.1
10.1

0.8
0.1
0.1
0.2

-

-

≦5

-

PO4-2mg/L(P0.65mg/L)

Yellow highlight: Not passed the national surface water standard category 4
National environmental standard, surface water category 4: water source use for consumption
and utilization but need disinfection, suitable for industrial use, receiver of wastewater fromcity, community, etc…

• COD-Cr of water in the canals are higher than the value set in national
environmental standard, surface water category 4.
• BOD5 of water in the 2 public canals are 19-32 mg/L. It is expected that
BOD5 will be highest in March-April, water quality could be worse thanprevious survey (JICA project report: BOD5 2-38 mg/L in Vientiane Capitalduring 2015-2016).

24

Facilities’ Treatment performance - Result of water quality analysis
No.

Treatment Type

Effluent standard-discharge from toiltet
1
2

3

4

5

Temp.
C

pH

EC
uS/cm

DO
mg/L

TSS
mg/L

COD-Cr
mg/L

BOD5
mg/L

T-P
mg/L

T-N
mg/L

NO3 -N
mg/L

-

6-9

-

-

50

125

30

-

-

-

Anaerobic-1(CBS)

Influent

28.0

7.4

337

6.3

85.0

280

>60

3.7

42.5

3.9

Effluent

28.6

6.8

443

5.4

170.0

116

35

4.3

39.9

3.0

Anaerobic-2

Influent

28.7

7.5

1545

4.2

74.0

236

>60

8.7

2.3

(CBS)

102.0

Effluent

28.8

7.6

520

4.3

9.0

16

12

1.9

10.3

4.8

Anaerobic-3(RESan)Influent

28.7

7.3

442

4.9

42.0

120

54

3.1

27.5

1.9

Effluent-Line1

28.3

7.1

632

4.0

7.2

12

15

3.3

30.1

1.3

Effluent-Line2

29.1

7.2

621

4.1

5.6

<5

18

3.7

31.1

1.2

Anaerobic-4(RESan)Influent

24.1
23.9

8.0
8.0

3214
1336

3.6
3.3

85
60

220
260

85
120

7.1
17.3

4.2
34.0

0.58
1.34

Anaerobic +Planted gravel+
Aeration+disinfection

Influent

24.7
25.7

6.4
6.8

444
417

4.3
3.6

56.0
5.6

126
32

68
26

0.94
0.79

22.4
15.2

1.0
0.6

Influent

23.9
20.3
23.2

7.0
7.3
7.1

450
478
1400

3.7
3.21

2.2
1.2
63.5

25
7
204

16
6
115

0.83
0.84
6.95

20.3
20.9
7.5

0.4
0.3
0.51

Effluent

23.9

7.1

1198

3.05

32

108

45

5.4

33.5

0.29

Influent

28.2

7.7

1125

4.2

62.0

332

>60

7.7

62.2

2.3

Effluent

29.4

7.6

662

7.5

9.6

28

23

7.3

44.1

-

6

Septic Tank

7

JohkasouEffluent
Effluent-AF
Effluent-PG
Effluent-UV

Yellow highlight:

Not passed the national effluent standard• Effluent BOD5 of 3 DEWATS passed the effluent standard• BOD5 of 2 DEWATS, and a Septic tank did not pass the effluent standard.
• Johkasou gave high performance in treating high concentration of COD and BOD

Case of community decentralized wastewater treatment system
Parameter

Inflow/
outflow

Unit

Number ofusers

Designedcondition(2010)*

Sampling
in 2011**

Chanthavilay This
et al
time
(2017)***(2022)

146
Inflow

mg/L

970

485

280

COD-cr

Outflow

mg/L

80

359

116

BOD5

Inflow

mg/L

540

82

226

>60

Outflow

mg/L

28

36

162

35

*,** Source: Summary Final Report-The Study on Improvement of Water Environment in Vientiane City, Lao
People’s Democratic Republic. ***International Journal of Advance Research, 5(4), 335-344.

• Effluent BOD5 is almost the same with the value in 2011. It
shows that the treatment facility still operates well, maybe
because desludging was conducted 4 months ago.
• However, the value is slightly over effluent BOD5’s national
environmental standard for community village ( BOD5 30 mg/L)

25

Case of community decentralized wastewater treatment system

26

Plain view

S

ABR

Cross section view

AF

Aeration pond

UV

Planted gravel filter

Source: THPC & BORDA Lao

27

Case of community decentralized wastewater treatment system)
Parameters

DesignIn

Actual (2012-2022)
Eff

Influent(Average)

Performance(%)

THP-004

THP-005

<50

242

189

215

17

87

20

46

40

43

9

75

T-N

26.2

17.3

14.0

13.2

32

T-P

1.7

2.3

2.1

1.1

45

12*106

16*106

14*1060.05*106

99

TSS
BOD

540

Coliform

AVG

Effluent(Average)
THP-008

80

80

0

56

18

2012

2013

40

13

12

2015

2016

2017

Inlet

29

42

6

23

14

35

20

29

32

40

60

67

60

10

9

6

4

5

2018

2019

2020

2021

2022

Outlet% Good monitoring and maintenance Water quality data for 10 year period is available

20

Removal percentage (%)

100

79

100

47

Average BOD(mg/L)

AVERAGE OF BOD50

Source: THPC

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Fecal sludge treatment facilities• In Vientiane capital, fecal sludge gathered from the septic tanks aredelivered by vacuum trucks to the fecal sludge treatment plant(FSTP) in Nahai village (Xaysettha District), and KM 32 landfill.
• Vientiane capital has regulation on management of de-sludging entities(Governor’s agreement, No. 0522/VT, dated 31 May 2018)• However, there is no technical guideline or SOP for de-sludge
process (sludge collection, transportation and disposal)

FSTP in Nahai village Xaysettha District (from 2017)
Source: Somsanouk Phommakhot (2020)
Updates of Water Environment Governance in Lao PDR

Sludge disposal at KM32 landfillFecal sludge treatment plant in Vientiane capital - Good Model

Receiving and Screening Tank

Packed fertilizer for sale

Treatment by plants

Dried fertilizer

29

Fecal sludge treatment plant Poor operation and maintenance of the fecal sludge treatment plants
 No technical guideline or SOP for desludging

30

Summary

31• WEPA action program in Lao PDR focus on

1. Identifying the legal, institutional, financial, technical issues for
improving domestic wastewater management systems in Lao PDR
2. Providing scientific basis for improvement of wastewater management
system•Survey on wastewater quality and performance of wastewater
treatment systems in 3 cities: Vientiane capital, Luang phrabang,
and Khammouane province.

3. Providing Training material for maintenance and operation of Septictank and decentralized waste water treatment facilities, and drafting thetechnical guidelines.
4. Enhancement of technical capacity of relevant stakeholders for a better
domestic wastewater management.

Summary-Findings from field survey

32

1. Organic pollutant in public canals was higher than surface water category 4 national
environmental standard.
2. Some DEWATS facilities operated well and passed the effluent standard. However, BOD5
of 2 DEWATS , and a Septic tank did not pass the effluent standard.
3. Manual on maintenance of DEWATS were available . However, regular monitoring andmaintenance were lacking in some facilities, especially thick layer of scum and lot of
garbage were observed in sedimentation chambers of some DEWATS facilities.
4. Some operators were lack of understanding on the technical operation of DEWATS.
5. Frame and holders of manhole cover got erosion, which made it difficult to open thechambers. User friendly design may be needed.
6. Lack of technical guideline or Standard Operation Procedure for Septic tank anddecentralized waste water treatment systems.
7. Most of facilities did not have specific budget and budget plan for operation andmaintenance of the facilities.
Necessary to have training material for O & M of septic tank and decentralized waste
water treatment system and enhance knowledge, skill of operators and relevant entities

Acknowledgement• Ministry of the Environment, Government of Japan(Support fund for this WEPA action program)• Institute for Global Environmental Strategies (IGES)• Department of Water supply and Department of
Housing and Urban planning, MPWT
• DONREs of Vientiane Capital and Luang Prabang
Province• Luang Prabang Urban Service Office• Vientiane City Office for Management and Service• National Academic for Politics and Public Administration• Theun Hin Boun Power Company• BORDA Lao• Lao-Japan Airport Terminal Service (L-JATS)
• AIT

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References
1.
2.
3.
4.

National report on state of environment for 5 years period 2016-2020, MONRE (2021).
National Environmental Quality Standards. Pollution Control Department, MONRE (2017).
National policy on water supply, sanitation and hygiene (2019).
Vision to 2035, and 9 year strategy on development of water supply and sanitation sector (20222030) , MPWT (March, 2022)
5. BORDA Laos DEWATS Service Packages. https://borda-sea.org/wpcontent/uploads/2019/02/20160721_LBOR_DEWATS-Brochure.pdf
6. Erick BaetingsO’LearyDeclan, Rapid assessment of household sanitation services Vientiane, Lao
PDR. WSP (2010).
7. Johkasou Technology JECES (2022).
8. The project for urban development master plan study in Vientiane capital. JICA. (2011).
9. Project completion report-the project for urban water environment improvement in Vientiane
Capital in the Lao People’s Democratic Republic. (JICA, 2017).
10. State of pollution Savannakhet province year 2020.
11. State of pollution Khammouane province year2020 .
12. Minaphone Chanthavilay, Wang, Wang Ying and Fengting Li.Hongtao. (2019). International Journalof Advance Research, 5(4), 335-344.
13. Water and Sanitation Program. (2016). Latrine Sales Agent Trainee Handbook (Lao PDR).
14. Agreement of Vientiane Capital’s governor on management and desludging service fromhousehold in Vientiane Capital (No. 0522/VT, dated 31 May 2018)34