presentationvietnamcase studyexperthybad

8/3/2019 PresentationVietnamCase studyExpertHyBad

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Vietnam Case study

and the

Pitfalls in conducting a

national assessment on

wastewater use in

agriculture


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Vietnam with a rainfall of 1700 to 2000

mm, its population of 77 mill. residingon 333000 km2.

What is the significance ofwastewater use for agriculture andaquaculture?


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Survey of 30 major cities in Vietnam

explores the extent of urban wastewater use

and analyzes the main causes andconsequences of its use in Vietnamese urban

and peri-urban agriculture and aquaculture.

This is the first phase of a longer term study proposed to be carriedout in Vietnam with the aim to improve the understanding of the use

of wastewater in agriculture and aquaculture, and its health and

environmental impacts in the context of integrated water resources

management


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The scope of nationwide surveycovers:

Water supply information

Sanitation and sewerage infrastructure

Wastewater related information: sources,

management

Production information on agriculture andaquaculture in wastewater use area

General Social health and crop impact

Information


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Stratification scheme for selection ofsample

57 provinces + 4 major cities

8 agro-ecological

Criteria for selection: Population, accessibility, exclude no ww areas and

southern floodplains

30 cities selected covering 7 agro-ecological zones (northwest mountainous regionexcluded)


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Cities selected

Northern part Central part Southern part

N.E RRD N.C.C S.C.C C.H S.E MRD

Viettri

Thainguyen

Bacgiang

Bacninh

Namdinh

Ninhbinh

Haiduong

Hanoi

Haiphong

Thaibinh

Hadong

Thanhoa

Vinh

Hatinh

Donghoi

Dongha

Hue

Danang

Quangngai

Tuyhoa

Tamky

Quynhon

Buonmathuot

Dalat

Pleiku

Thudaumot

Bienhoa

Hochiminh

Vungtau

Tanan


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Metropolitan area: urban center

+ suburban areasInformation researched:

Water supply andsanitation infrastructure+ volumes

Main industrial act.Connection to sewers,type of ind.activity,proportion of ind.ww,

Treatment facility status, presence ofnatural ponds, use

ww irrigated areas,extents, cropping pattern,sources of water

Aquaculture volumes,production

Livelihoods agri, aqua

Reasons for use, non-use

Payment for ww


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Urban wastewater: blackwater, greywater,industrial, commercial, run-off

Irrigated areas where wastewater is used

directly from ww canal or justdownstream of a discharge point after

dilution through discharge into surface

water.

Wastewater drainage canal Drainage canal of an irrigation system

receiving wastewater

Irrigation canal receiving wastewater

Definitions:


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Methodology

1 pilot city to refine questionnaire

Fieldwork reqd. 3 months (Aug Oct) with 3 teams,7 staff members

In depth interviews with officials

Dept. Land administration

Dept of Statistics

Dept. Agriculture and Rural Development

Irrigation and Drainage Management, Company

Dept. of Science, Technology, and Environment

Data analysis: categorisation by class and regions, using excel

worksheets


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Classes of cities and population

Class of

City

Total

Numberof cities

No. of cities

surveyed

Population

covered

% of total

Populationcovered

% of total

countrypopulation

1 2 2 7 905 849 53.7 10.3

2 12 10 4 552 488 30.9 5.9

3 6 3 595 838 4.0 0.8

4 25 10 1 221 853 8.3 1.6

5 14 5 454 315 3.1 0.6

Total 61 30 14 730 343 100 19.1

Water supply: 40% (cities) surface, 17 % ground, 43% both


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Wastewater: by city class

Class of

City

Industrial ww

as total ww

%(range)

% of domestic

ww drained

into MSS

Sewer/drainage (km)

Avg. km/city

I 17 (11-34) 75 1034 / 517

II 39 (8-59) 64 432 / 43

III 11 (7-16) 61 35 / 12

IV 39 (1-67) 55 264 / 26

V 14 (1-33) 47 144 / 29

Overall 24 71 1909 -


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Water & wastewater: by region

Regions Consumptive

Volume

(m3/d)

Total ww

(m3/d)

Ind. ww

(m3/d)

Ind. Ww

as total

ww%(range)

Northeast 120 285 97 629 48 000 49 (15-66)

RRD 879 661 586 443 227 800 39 (1-59)

North central coast 132 928 107 403 20 038 19 (6-33)

South central coast 210 520 152 762 52 822 35 (1-67)

Central highland 83 398 65 176 7 225 11 (7-16)

Mekong River Delta 22 484 17 785 1 912 11 -

Southeast 1 231 045 1 058 085 147 800 14 (9-52)

Overall 2 680 321 2 085 283 505 597 24 -


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Setting the context:Pattern and extent of wastewater use

28/30 cities ie 93% use wastewater either for

agriculture or aquaculture or both In these 28 cities

80% use for agriculture

63 % for aquaculture

Exception Haiphong with > 45% agri. land,

but no ww use


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Agricultural land use

5 of6 cities with agriculture land exceeding

10000 ha are in high population cities

Ratio of agri. land to total land exceeds 45%

for 3 out of 4 of the largest cities

importance of urban/peri-urban agriculture


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Agri. land and ww agriculture: by class

Class

of

City

Agricultural land as %

total land area

waste water

irrigated

area

(ha)

WW irrigated area as

% agricultural

landAvg. Range Avg. Range

I 46.50 - 2561 1.83 1 - 4

II 28.14 8-58 485 0.43 0 - 4

III 21.22 7-40 215 1.15 0.3 - 3

IV 56.17 42-66 1368 5.40 0 - 17

V 27.74 16-74 243* 1.48* 0 - 10

Total 35.04 - 4871* 1.56* -

*excludes NinhBinh


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Agri. land and ww agriculture: by region

Regions Agricultural land as %

total land area

Area irrigated

with waste

water (ha)

WW irrigated area as %

Agricultural land

Avg. Range Avg. Range

Northeast 45.55 42-56 237 2.16 0-15

RRD 46.34 43-65 2346* 1.93* 0-17

North central

coast33.78 16-74 722 4.73 0-12

South central

coast 15.19 8-52 272 0.82 0-4

Central highland 21.22 7-40 215 1.15 0.4-3

MekongRiver 65.78 - 25 0.46 -

Southeast 43.68 10-56 1055 0.97 0-1

Total 35.04 - 4871* 1.56* -


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Cropping pattern: by region

Regions Spring Summer Winter

Paddy upland veg Paddy upland veg Paddy upland veg

NE 58 21 21 58 21 21 0 0 0

RRD 86 7 6 85 4 3 0 4 3

NCC 79 10 11 96 0 1 20 13 22

SCC 83 14 2 98 2 0 0 6 1

CH 35 18 47 47 6 47 0 3 3MRD* 75 10 15 15 15 70 50 25 25

SE 60 10 30 89 0 11 1 0 0

Overall 76 10 14 85 4 7 3 4 5

*only one city - Tanan


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Why use wastewater for agriculture?

Unplanned discharge into natural water

courses, drainage canals or irrigation canals irrigation with wastewater unavoidable

Wastewater is diluted sewage mostly

9/24 cities recognised the nutrient and water

value


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Aquaculture using wastewater

19/30 cities use ww for aquaculture usually in

natural ponds Wastewater fish production = 6358 t/y of

which 3380 tons is from Hanoi

HCMH no fish farming with wastewater butfish production is from contaminated water

bodies including river.


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Livelihoods: by city class

City class No. of ww persons as a % of population*

agriculture aquaculture

Class I 1.0 0.10

Class II 0.28 0.08

Class III 5.03 -

Class IV 0.47 0.03

Class V 3.62 0.02

Total 0.97 0.09

*HH info.unavailable for some cities; HH x 5 = no. of persons


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Livelihoods: by region

Regions No. of ww persons as a % of population*

agriculture aquacultureNortheast - -

RRD 1.42 0.18

North central coast 2.32 0.25

South central coast 0.17 0.09

Central highland 5.03 -

Mekong River Delta 0.14 0.04

Southeast 0.35 0.01

Overall 0.97 0.09


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Natural ponds for treatment

Originally designed for flood control primarily

now receives wastewater

16 cities with pond areas exceeding 10 ha

Retention times vary between 1-122

14 cities are under13 days

EFFECTIVENESS is questionable without monitoring


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Health & environment

No substantive evaluation of H & E impacts

but perceptions recorded More than half the local authorities

interviewed were aware of negative impacts

Preference for alternative sources if availablebut no plans for this

Use of ww not actively discouraged


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Conclusions

In water rich countries, reliability and

availability factors do not influence decisionfor its use

In larger cities urban/peri-urban agriculture

plays an important role in providing food for

cities Out of 35 % agricultural land nearly 2 % is

irrigated with wastewater

( 5000 ha for 30 cities)


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Conclusions

Wastewater agriculture and aquaculture

provide llivelihoods for1 % and 0.1 %respectively of the population

(aquaculture = 1/10 agriculture)

Smaller cities which produce lower volumes

of ww have a higher % of ww agriculture other factors influence use


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Conclusions ( contd)

Paddy is the predominant crop in ww

irrigated areas for Vietnam From cropping pattern it is clear that there is

very little use of wastewater in winter season

Natural ponds used for flood control nowserve treatment purpose as well. Design

parameters for treatment not met.


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Lessons relevant to typology and

national assessments

Clear typology required for common

understanding we nearly met our waterloo invietnam!!

Explain the term wastewater (level of pollution). In

Vietnam we defined what was meant by

wastewater that was used Well trained surveyors/teams with clear

understanding of terminology and typology

essential


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Lessons relevant to typology and

national assessments

Provide clear guidelines for completing

questionnaire for every question an explanation Proposed Questionnaire for NAs very

comprehensive. Data collection at national level

time consuming

At city level, in data short countries, avoid

seeking information that is confusing or difficult

to obtain, unless investigators are trained


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Thank you..

Doan Tuan and his team from CIWSR,

Vietnam Phung Dac Cam and his team, NIHE

KVL, Copenhagen

DHI,

Denmark

Univ. of Copenhagen

DANIDA

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