The Study on Water Quality of the Return Flow in

Lower Tap Salao Irrigation Project

Hungspreug N.1 Chooaksorn W.2 and Sudcha P.3

Department of Environmental Science, Faculty of Science and Technology,

Thammasat University, Patumtanee, ThailandEmail : 1 n_hungspreug@yahoo.com , 2 chooaksorn@yahoo.com ,

3 psudcha@yahoo.com

Purpose Purpose

Determine and compare water quality of the irrigation canal and drainage canal in

Sakaekrang river basin, Thailand

Department of Environmental Science , Thammasat University

•Water degradation was clearly caused by agriculture sources (non-point sources).

IntroductionIntroduction

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Introduction (cont’)Introduction (cont’)

Irrigation canals Irrigated area

Drainage canals

Water Quality ?

• In 1993, in USA 65 % of rivers suffered the impacts from non-point source pollution.

(US Department of Pollution Control, 2002).

• In Thailand non-point sources pollution is the cause of severe water pollution. (Simachaya, 2000)

Introduction (cont’)

Introduction (cont’)

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MethodologyMethodology

Department of Environmental Science , Thammasat University

Study Area

Study Area

• Southern Tap Salao in with part of Tab Salao irrigation project in the upper central part of Thailand.

• covering 14,000 ha.

• The water supply to this irrigation project came from the upstream Tab salao reservoir.

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Southern Tap Salao irrigation project

Sampling Stations

Sampling Stations

• 45 water quality sampling stations.• irrigation canal 22 stations

• drainage canal 23 stations

• collected samples during January 19th-22rd, 2007

Department of Environmental Science , Thammasat University

I05

I06

I07

I08

I09

I10

I11

I13

I14

I15

I16

I18

I21

D03 D04 D07 D08 D09 D11 D13 D15 D16 D18 D21D19

D02

D06 D14

D05 D20

I04

I03

I02

I12

I17

I19

I20

SECONDARY RIGHT 1

SECONDARY RIGHT 2

THIRDLY LEFT 1 – LEFT 1

SECONDARY LEFT 1

THIRDLY RIGHT 1 - RIGHT 1 -LEFT 1

THIRDLY RIGHT 1 - LEFT 1

RIGHT IRRIGATION CANAL

LEFT IRRIGATION CANAL

HUAI IJANG

HUAI THAP THAN

HUAI TAP SALAO

I22

I23

I01

D01

D10 D12

D17 D22

D

I

Office

Stations Irrigation canals

Stations Drainage canals Drainage canals

Irrigation canals

Water Quality Sampling Stations

Drainage canal stations

Irrigation canal stations

Irrigation canal stations

Drainage canal stations

Parameters. Parameters.

• pH

• Conductivity (EC)

• Temperature (Temp)

• Turbidity (Tur)

• DO

• BOD

• NO3–-N

• NH3+-N

• PO43--P

• TS• TDS• SS

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ResultsResultsDepartment of Environmental Science , Thammasat

University

Parameters

UnitIrrigation canals Drainage canals

Range Average

Range Average

pH - 6.78-9.71 7.58 6.59-7.79 7.36

EC µm/cm

122.73-369.80

185.02

104.30-413.80

217.10

Temp. °C 26.03-33.17

29.93 25.37-32.40

28.75

Turbidity NTU 6.62-126.33

48.83 7.03-111.00

31.38

DO mg/l 1.00-8.97 4.37 0.80-4.80 3.27

BOD mg/l 0.53-6.77 3.18 0.25-5.37 1.89

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Parameters

Unit Irrigation canals Drainage canals

Range Average

Range Average

NO-3

mg/l 0.04-0.15 0.09 0.05-0.24 0.09

NH+3

mg/l 0.04-0.25 0.12 0.03-0.36 0.12

PO43- mg/l 0.11-0.40 0.20 0.07-0.34 0.15

TS mg/l 122.50-364.00

205.79 122.50-454.33

211.19

TDS mg/l 105.17-262.00

159.18 111.50-441.33

184.13

SS mg/l 7.44-133.33 46.61 5.00-93.56 27.06

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Parameters

UnitIrrigation canals Drainage canals

Range Average

Range Average

pH - 6.78-9.71

7.58

6.59-7.79

7.36

Conductivity µm/cm 122.73-369.80 185.02 104.30-413.80 217.10

Temperature °C 26.03-33.17 29.93 25.37-32.40 28.75

Turbidity NTU 6.62-126.33 48.83 7.03-111.00 31.38

DO mg/l 1.00-8.97 4.37 0.80-4.80 3.27

BOD mg/l 0.53-6.77 3.18 0.25-5.37 1.89

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pH

4

6

8

10

Irrigation canals Drainage canals

max

min

avg

Parameters

UnitIrrigation canals Drainage canals

Range Average

Range Average

pH - 6.78-9.71 7.58 6.59-7.79 7.36

EC µm/cm

122.7-369.8

185.0 104.3-413.8

217.1

Temperature °C 26.03-33.17 29.93 25.37-32.40 28.75

Turbidity NTU 6.62-126.33 48.83 7.03-111.00 31.38

DO mg/l 1.00-8.97 4.37 0.80-4.80 3.27

BOD mg/l 0.53-6.77 3.18 0.25-5.37 1.89

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100

150

200

250

300

350

400

450

Irrigation canals Drainage canals

max

min

avg

Conductivity

µm/cm

Parameters

UnitIrrigation canals Drainage canals

Range Average

Range Average

pH - 6.78-9.71 7.58 6.59-7.79 7.36

Conductivity µm/cm 122.73-369.80 185.02 104.30-413.80 217.10

Temp °C 26.0-33.2

29.9 25.4-32.4

28.7

Turbidity NTU 6.62-126.33 48.83 7.03-111.00 31.38

DO mg/l 1.00-8.97 4.37 0.80-4.80 3.27

BOD mg/l 0.53-6.77 3.18 0.25-5.37 1.89

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20

25

30

35

Irrigation canals Drainage canals

max

min

avg

Temperature

°C

Parameters

UnitIrrigation canals Drainage canals

Range Average

Range Average

pH - 6.78-9.71 7.58 6.59-7.79 7.36

Conductivity µm/cm 122.73-369.80 185.02 104.30-413.80 217.10

Temperature °C 26.03-33.17 29.93 25.37-32.40 28.75

Tur NTU

6.6-126.3

48.8 7.0-111.0

31.4

DO mg/l 1.00-8.97 4.37 0.80-4.80 3.27

BOD mg/l 0.53-6.77 3.18 0.25-5.37 1.89

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0

50

100

150

Irrigation canals Drainage canals

max

min

avg

Turbidity

NTU

Parameters

UnitIrrigation canals Drainage canals

Range Average

Range Average

pH - 6.78-9.71 7.58 6.59-7.79 7.36

Conductivity µm/cm 122.73-369.80 185.02 104.30-413.80 217.10

Temperature °C 26.03-33.17 29.93 25.37-32.40 28.75

Turbidity NTU 6.62-126.33 48.83 7.03-111.00 31.38

DO mg/l

1.0-8.97

4.37

0.8-4.8 3.27

BOD mg/l 0.53-6.77 3.18 0.25-5.37 1.89

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0

2

4

6

8

10

Irrigation canals Drainage canals

max

min

avg

Dissolved Oxygen (DO)

mg/l

Parameters

UnitIrrigation canals Drainage canals

Range Average

Range Average

pH - 6.78-9.71 7.58 6.59-7.79 7.36

Conductivity µm/cm 122.73-369.80 185.02 104.30-413.80 217.10

Temperature °C 26.03-33.17 29.93 25.37-32.40 28.75

Turbidity NTU 6.62-126.33 48.83 7.03-111.00 31.38

DO mg/l 1.00-8.97 4.37 0.80-4.80 3.27

BOD mg/l

0.5-6.8 3.2 0.3-5.4 1.9

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0

2

4

6

8

10

Irrigation canals Drainage canals

max

min

avg

Biochemical Oxygen Demand (BOD)

mg/l

Parameters

Unit Irrigation canals Drainage canals

Range Average

Range Average

NO-3

mg/l

0.04-0.15 0.09 0.05-0.24 0.09

NH+3

mg/l

0.04-0.25 0.12 0.03-0.36 0.12

PO43- mg/l 0.11-0.40 0.20 0.07-0.34 0.15

TS mg/l 122.50-364.00 205.79 122.50-454.33 211.19

TDS mg/l 105.17-262.00 159.18 111.50-441.33 184.13

SS mg/l 7.44-133.33 46.61 5.00-93.56 27.06

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0

0.1

0.2

0.3

0.4

0.5

Irrigation canals Drainage canals

max

min

avg

NO3-N

mg/l

0

0.1

0.2

0.3

0.4

0.5

Irrigation canals Drainage canals

max

min

avg

NH3-N

Parameters

Unit Irrigation canals Drainage canals

Range Average

Range Average

NO-3

mg/l 0.04-0.15 0.09 0.05-0.24 0.09

NH+3

mg/l 0.04-0.25 0.12 0.03-0.36 0.12

PO43- mg

/l0.11-0.40

0.20 0.07-0.34

0.15

TS mg/l 122.50-364.00 205.79 122.50-454.33 211.19

TDS mg/l 105.17-262.00 159.18 111.50-441.33 184.13

SS mg/l 7.44-133.33 46.61 5.00-93.56 27.06

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0

0.1

0.2

0.3

0.4

0.5

Irrigation canals Drainage canals

max

min

avg

Phosphate Phosphorus (PO34--P)

mg/l

Parameters

Unit Irrigation canals Drainage canals

Range Average

Range Average

NO-3

mg/l 0.04-0.15 0.09 0.05-0.24 0.09

NH+3

mg/l 0.04-0.25 0.12 0.03-0.36 0.12

PO43- mg/l 0.11-0.40 0.20 0.07-0.34 0.15

TS mg/l

122.5-364.0

205.8 122.5-454.3

211.2

TDS mg/l 105.17-262.00 159.18 111.50-441.33 184.13

SS mg/l 7.44-133.33 46.61 5.00-93.56 27.06

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100

150

200

250

300

350

400

450

500

Irrigation canals Drainage canals

max

min

avg

Total Solid (TS)

Parameters

Unit Irrigation canals Drainage canals

Range Average

Range Average

NO-3

mg/l 0.04-0.15 0.09 0.05-0.24 0.09

NH+3

mg/l 0.04-0.25 0.12 0.03-0.36 0.12

PO43- mg/l 0.11-0.40 0.20 0.07-0.34 0.15

TS mg/l 122.50-364.00 205.79 122.50-454.33 211.19

TDS mg/l

105.2-262.0

159.2 111.5-441.3

184.1

SS mg/l 7.44-133.33 46.61 5.00-93.56 27.06

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90

140

190

240

290

340

390

440

490

Irrigation canals Drainage canals

max

min

avg

Total Dissolved Solid (TDS)

Parameters

Unit Irrigation canals Drainage canals

Range Average

Range Average

NO-3

mg/l 0.04-0.15 0.09 0.05-0.24 0.09

NH+3

mg/l 0.04-0.25 0.12 0.03-0.36 0.12

PO43- mg/l 0.11-0.40 0.20 0.07-0.34 0.15

TS mg/l 122.50-364.00 205.79 122.50-454.33 211.19

TDS mg/l 105.17-262.00 159.18 111.50-441.33 184.13

SS mg/l

7.4-133.3

46.6 5.0-93.6 27.1

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0

30

60

90

120

150

Irrigation canals Drainage canals

max

min

avg

Suspended Solid (SS)

ConclusionConclusion

ConclusionConclusion

• The water quality in the irrigation canals was better than in drainage canals .

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• The water quality in the irrigation canal was classified as class 3 (medium clean)

(1) consumption after treatment

process.

(2) agriculture

Conclusion (cont’)Conclusion (cont’)

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• The water quality in the drainage canal was classified as class 4 (fairly clean)

(1) consumption after special treatment process

(2) industry

Conclusion (cont’)Conclusion (cont’)

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• The water quality in the irrigation canal was not significant different from that in the drainage canal.

Conclusion (cont’)Conclusion (cont’)

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•Water drained from Irrigated area which mostly claimed as non point sources pollutant somehow the irrigation area can acts as constructed wetland which can improve some water quality parameters.

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Conclusion (cont’)Conclusion (cont’)

RecommendationRecommendation

• Water qualities monitoring programme should be continued at certain sampling stations over a longer period.

Recommendation

Recommendation

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Acknowledgement

Acknowledgement

• Staff of southern Tap Salao irrigation project,

Royal Irrigation Department.

Department of Environmental Science , Thammasat University

Thank you for your attention.