In this paper, the mold of the behaviour of contaminations conveyance in River Indus from d/s of the Ghazi to its meeting with Kabul River, is discussed. For this intent, QUAL2K theoretical account developed by USEPA has been employed. For simulation intent, three scenarios were developed to analyze the worst status of H2O quality in Indus River during low flow season. Scenaro-1 was run for a low flow of 28 cumecs with the present status of effluent measure and quality. In Scenario-2, flow was unbroken same but wastewater measures were projected upto twelvemonth 2063 with same effluent quality as in twelvemonth 2002. In instance of Scenario-3, it was assumed that the effluent quality would be farther deteriorated to the extent so that BOD value would be in the scope of 80 mg/l in the undertaking life. The river flow and effluent measures were unbroken same as that in instance of Scenario-2. The theoretical account consequences show that the DO and BOD will stay within the allowable bounds ( DO & gt ; 4mg/l and BOD & lt ; 8mg/l severally ) in instance of all three scenarios.The theoretical account consequences show that if the BOD of effluent increases up to 80 mg/l above the value which was at the start of the undertaking, the quality of the Indus River flood plain will deteriorate jeopardizing the aquatic life. In order to maintain the BOD value of effluent within the scope of 80 mg/l, proper extenuations and direction programs have to be evaluated and implemented.

1. Introduction

Water is prerequisite for life and development. This is the ground that from early age of the humanity, most of the population was ab initio settled along the rivers and watercourses. Every usage of H2O generates wastewater. Natural watercourses are ever considered as an easy manner to dispose off many sorts of wastewaters. The doctrine behind this pattern is that the wastes are diluted and washed off every bit good as diluted by the watercourse H2O and the same are non seeable at the dumping sites.

The natural stream/river H2O contains substances derived from the environment, both natural and semisynthetic. The sum of these components in H2O determines its quality. Consequently, trying the H2O and measurings of the concentrations of assorted components can quantify the H2O quality. Such information about river H2O quality can be critical for finding the suitableness of H2O for assorted intents, such as domestic agricultural and industrial utilizations use, nutriment of aquatic life and receiver of waste H2O in natural watercourses, etc.

It is believed that merely proper manner for finding the quality of H2O, is by chemical analysis of H2O samples. However, other inquiries might originate such as understanding the different dealingss between the H2O quality parametric quantities and belongingss, anticipation of future H2O quality, gauging the effects of river flow and H2O quality direction. Such jobs can non be solved by mere chemical analysis and it is here that theoretical accounts can be used to hold important and decisive function. Basically, river H2O quality theoretical accounts are tools for analysing, generalizing and foretelling H2O quality.

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2. Ghazi Brotha Hydropower Project ( GBHP )

The Water and Power Development Authority ( WAPDA ) of Pakistan has late implemented the Ghazi-Barotha Hydropower Project ( the Undertaking ) on the Indus River with the fiscal aid of the World Bank and other international giver bureaus.

The Undertaking was planned to use the hydraulic caput for power coevals that is available between the tailrace of the Tarbela Dam and the meeting of the Indus River with Haro River. In this range the Indus River beads by 76 m in a distance of 63 kilometer. This is entirely a power coevals undertaking with an installed capacity of 1450 MW. The Undertaking has three chief constituents i.e. a bombardment located about 7 kilometers downstream of Tarbela dike organizing a pool, a 52 kilometer long concrete-lined power channel to deviate the flow from bombardment to a power composite, which is located near the meeting of Indus and Haro rivers.

There are a figure of small towns near to the left and right Bankss of the river downstream of the bombardment which have no proper drainage system and their effluent either discharge straight into the river or soak into the land and reaches the river indirectly through infiltration ( GBHP Report on Supplementary Environmental Studies, PHC, 1992 ) . The other nearby small towns and towns, which are comparatively off from the river, dispatch their effluents into the natural watercourses, which finally join the river.

The flow to the power channel of GBHP will dwell of release from Terbela Dam. During the low-flow period ( from early October to mid-May ) , when Tarbela releases shall be less than the channel capacity of 1,600 cumecs ( about 56,450 cusecs ) , it will non merely ensue in decrease in the flows in the power channel but besides less H2O will be available for let go ofing into the river downstream of the bombardment. These releases may make to about nil during early 20 yearss of January. However, WAPDA has ensured a minimal release of 28 cumecs ( about 990 cusecs ) during this period. ( GBHP Report on Supplementary Environmental Studies, PHC, 1992 ) . It is apprehended that the H2O quality of Indus Floodplain will be adversely affected by the effluent, which is being disposed off into the river peculiarly during low flow period.

The addition of contaminations concentration due to cut down flows may menace to the aquatic life particularly fish. Keeping in position the dismaying state of affairs of the contaminations in river, an attempt was made to pattern the behaviour of contaminations conveyance in River Indus from D/S of the Ghazi to its meeting with Kabul River ( about 40 kilometers stretch ) . For this purpose QUAL2K theoretical account developed by USEPA was used.

2.1. Description of the Study Area

For the present research survey, River Indus was selected sing alteration of its present position by deviating the discharge of river from Ghazi to Brotha through a channel. For this intent a range of about 40km between Ghazi to the point of meeting of River Indus with Kabul was selected. The survey country is shown in Figure 1. There are seven wastewater semen storm-water drains on Left Bank and four on Right Bank side of the river, which are disposing of wastewaters into the river in the selected range. These drains join the river at different ranges get downing from km 00+750 and ending at about kilometer 37+000. A line diagram of the proposed survey range is shown in Figure 2.

Figure 1. Ghazi-Barotha Hydropower Project Layout.

Figure 2. Conventional Presentation of the Selected Reach of River Indus

2.2. Dispatch Measurement

The discharges of drains measured on monthly footing for a twelvemonth about. The table-1 shows the discharge measured at different points.

Table 1. Discharge Measurements of Potential Beginnings Joining Indus River in the Study Area.

Time period

Potential Beginnings of Left Bank ( Wastewater Drains/Nullahs )

A

A

A

A

A

A

Potential Beginnings of Right Bank ( Nullahs/Drains )

A

A

A

A

A

Accumulative Monthly Discharge

( cumec )

Ghazi-I

Ghazi-M

Khalo-I

Khalo-II

Qazipur

Ghurghushti

Chel

Bada Khawar

Gadoon Amazai I

Gadoon Amazai II

Badri Khawar

Drain -I

Drain II

September

Discharge

0.0028

0.016

0.004

0.009

0.0051

1.06

0.929

0.03

0.0212

0.049

2.73

A

4.8561

October

Discharge

0.0046

0.0102

0.0019

0.0014

0.003

0.262

0.3468

A

0.0267

0.0804

2.93

0.74

0.1093

4.5163

November

Discharge

0.0036

0.0056

0.0028

0.0035

0.0034

0.21

0.188

0.0062

0.084

2.42

1.07

0.181

4.1781

December

Discharge

0.00088

0.0026

0.00028

0.0026

0.0017

0.145

0.142

0.005

0.057

2.196

0.972

0.241

3.76606

January

Discharge

0.0024

0.0038

0.0005

0.0005

0.002

0.347

0.245

0.006

0.065

2.25

0.375

0.126

3.4232

February

Discharge

0.0013

0.003

0.00098

0.00098

0.0013

0.333

0.282

0.0067

0.017

1.58

0.301

0.058

2.58526

March

Discharge

0.0068

0.0049

0.0018

0.0107

0.0021

0.444

0.409

0.0011

0.041

2.65

1.29

0.49

5.3514

April

Discharge

0.00143

0.0043

0.00187

0.00093

0.0028

0.309

0.308

0.00198

0.0386

1.65

0.70

0.375

3.39391

May

Discharge

0.001

0.0053

0.0013

0.00065

0.0025

0.252

0.333

A

0.0022

0.014

1.85

0.676

0.106

3.24395

June

Discharge

0.0014

0.0282

0.00042

0.00042

0.0021

0.23

0.199

0.0071

0.014

1.8

0.7

0.12

3.10264

July

Discharge

0.002

0.011

0.00053

0.00053

0.0025

0.388

0.141

12.13

0.0039

0.0103

1.83

0.75

0.102

15.37176

August

Discharge

0.00114

0.0136

0.00073

0.000365

0.0032

0.302

0.724

1.52

0.0011

0.034

5.32

1.38

0.415

9.715135

September

Discharge

0.001

0.0127

0.001

0.001

0.0054

0.252

0.444

A

0.009

0.01

3.41

A

0.321

4.4671

2.2. Quality Measurement

For this survey, H2O samples were collected from river and other storm H2O channels/drains. The samples were taken in high-flow and low-flow phases of the streams/river to find the fluctuation of contaminations. The physical testing, nevertheless, remained continued with the activity of discharge measurings. Tables 2 and 3 provide the H2O quality consequences for the samples collected for left and right Bankss in high and low flow conditions.

Table 2. Physical, Chemical and Biological Test Results of River and Drainage Waters of the Study Area ( High-Flow Period -January )

Sr. No.

Name of Sample

Temp oC

pH

E.C

Aµs/cm

Make

ppm

Toxic shock

ppm

TDS

ppm

Human body

ppm

Pod

ppm

Chlorine

ppm

Fe

ppm

1

Indus River 30 m u/s of Ghazi Drain Outfall

17.9

8.54

170

8.9

1.5

125

0

0

14.5

0.11

2

Ghazi Wastewater Drain

24.7

7.27

676

3.1

10.5

349

57

191

15

0.01

3

Indus River 30 m d/s of Khalo Drain Outfall

19.1

8.37

167

8.1

0.5

165

0

5

14.5

0.1

4

Indus River 30 m u/s of Ghurghushti Nullah Outfall

22.5

8.1

425

6.7

0.5

272

0

0

21.5

0.05

5

Ghurghushti Nullah

19.2

8.68

181

9

0.5

123

0

0

14

0.08

6

Indus River 30 m d/s of Ghurghushti Nullah Outfall

21.5

8.51

180

8.8

1.5

167

0

0

21.5

0.01

7

Indus River 30 m u/s of Chel River/Nullah

19.3

7.98

201

8

4.5

98

0

0

16.5

0.14

8

Chel River/Nullah

23.3

7.99

511

6.7

4.5

322

0

14

25.5

0.09

9

Indus River 30 m d/s of Chel River/Nullah

17.8

8.03

176

9.1

5

96

7.7

0

10

0.15

10

Gadoon-Amazi Eastern Drain

20.5

6.76

609

0.5

124

259

32

0

34

0.16

11

Gadoon-Amazi Western Drain

19.6

6.94

695

0.6

17.5

314

78

374

41

0.2

12

Bada Khawar

No flow in Bada Khwar was available at the clip of trying.

13

Indus River 30 m d/s of Bada Khawar Outfall

18

7.3

263

7.9

3.5

119

0

4

10

0.14

14

Indus River 30 m u/s of Badri Khawar Outfall

18

8.57

197

9.1

1

242

5.5

0

20

Nothing

15

Badri Khawar

20

8.66

506

7.2

3.5

329

0

0

31

Nothing

16

Indus River 30 m d/s of Badri Khawar Outfall

18

8.68

499

8.4

5

463

6.6

0

26.5

Nothing

PEPA Standards*

= & lt ; 3A°C

6-9

A

A

200

3500

80

150

1000

2.0

Beginning: WAPDA ( 2003 )

*As per Statutory Notification of August 2000

Table 3. Physical, Chemical and Biological Test Results of River and Drainage Waters of the Study Area ( Low-Flow Period -January )

Sr. No.

Name of Sample

Temp oC

pH*

E.C

Aµs/cm

Make

ppm

Toxic shock

ppm

TDS

ppm

Human body

ppm

Pod

ppm

Chlorine

ppm

Fe

ppm

1

Indus River 30 m u/s of Ghazi Drain Outfall

13.7

8.2

242

8.6

1.5

140

6.0

0.0

6

0.05

2

Ghazi Wastewater Drain

14.6

7.45

685

3.9

133.0

340

66

107.0

58.0

0.37

3

Indus River 30 m d/s of Khalo Drain Outfall

15.2

8.68

326

7.8

0.5

150

6.0

33.0

11.0

0.04

4

Indus River 30 m u/s of Ghurghushti Nullah Outfall

11.2

8.82

260

8.3

0.5

170

15

17.0

10.0

Nothing

5

Ghurghushti Nullah

14.5

7.88

393

6.3

0.5

110

15.7

0.0

6.0

Nothing

6

Indus River 30 m d/s of Ghurghushti Nullah Outfall

12.5

8.3

365

7.3

0.5

170

12.3

0.0

10.0

Nothing

7

Indus River 30 m u/s of Chel River/Nullah

11.5

8.55

259

8.7

0.5

110.0

3

0

9

Nothing

8

Chel River/Nullah

10.3

8.06

447

6.9

0.5

200

6.0

16

18.0

0.12

9

Indus River 30 m d/s of Chel River/Nullah

12.3

8.51

267

8.5

1

120

1.5

0

8.0

Nothing

10

Gadoon-Amazi Eastern Drain

10.3

7.7

784

5.4

608

440

111.0

687.0

52.0

1.69

11

Gadoon-Amazi Western Drain

20

8.65

582

5

9.5

290

112.0

354

49.0

0.18

12

Bada Khwar

No flow in Bada Khwar was available at clip of trying.

13

Indus River 30 m d/s of Bada Khawar Outfall

11.7

8.2

230

7.5

1.0

130.0

3

115.0

8

0.01

14

Indus River 30 m u/of Badri Khawar Outfall

The outfall of Chel Nullah was cut off from the river brook.

15

Badri Khawar

11.7

8.2

531

7.9

0.5

300.0

4.5

41.0

19

16

Indus River 30 m d/s of Badri Khawar Outfall

13.4

8.68

284

8.5

0.5

180.0

0

0

12.0

Nothing

PEPA Standards*

= & lt ; 3A°C

6-9

A

A

200

3500

80

150

1000

2.0

Beginning: WAPDA

*As per Statutory Notification of August 2000

2.2. Model Description and Data Collection

The enhanced watercourse H2O quality theoretical account QUAL2K or Q2K that is intended to stand for a modernised version of the QUAL2E or Q2E. The theoretical account permits simulation of several H2O quality components in a ramification watercourse system. The conceptual representation of a watercourse used in the Q2K formation is a watercourse range that has been divided into a figure of sub-reaches or computational elements tantamount to finite differences.

QUAL2K is a comprehensive and various watercourse H2O quality, theoretical account. It can imitate up to 26 H2O quality components in any combination desired by user. The chief components including temperature, conduction, inorganic suspended solids, dissolved O, debris, slow CBOD, fast CBOD, dissolved organic N, ammonium hydroxide N ( NH4 ) , nitrate, N ( NO3 ) , dissolved organic P ( DOP ) , inorganic P, phytoplankton, bottom algae, pathogen, alkalinity, pH, TSS, NH3, Arbitrary non-conservative components, etc. The theoretical account has 17 worksheets of which 14 are used to come in informations while 3 are end product

The chief information demands for theoretical account was the discharge in each river range, the river cross-sections at different points, bed incline of the river and H2O quality of chief watercourse and feeders. The chief informations used in the theoretical account included:

River discharge

River cross-sections

River bed incline

River H2O temperature

Wind speed

Shade

Cloud screen

Water quality informations, etc.

The cross-sections of the River Indus for selected range were available at 43 points between bombardment and point of meeting of Indus River with Kabul River, which were obtained from Pakistan Hydro Consultants ( PHC ) , 2002. The selected cross-sections, which were used for the present survey, have been plotted with the aid of computing machine demoing the H2O degrees in different brook. The lone that portion of the cross-section was used in theoretical account where H2O has been found in the brook. . For given range, the norm of cross-sections has been taken. The discharge for range was besides known, so speed was calculated for every range. The latitude and longitude of the country were taken from Atlas of Pakistan ( 1992 ) . The other relevant information was collected from WAPDA Environmental Cell ( WEC ) , 2003. For the present survey, the parametric quantities selected for the theoretical account simulation include DO and BOD as the effluent, which is being disposed of into the river, is generated by families non industries.

3. Model Input

Harmonizing to theoretical account demands, the selected river range of 40 kilometers of length was divided into computational elements of different lengths. The entire selected length of the river was divided into 7 ranges as shown in Table 4. Each range is of 5 kilometers long except range nos. 4 and 7, which are 10 kilometers and 6 kilometers long severally. Reach 1 has four wastewater-cum storm H2O drains viz. Ghazi-I at km 00+750, Ghazi-M at km 01+000, Khalo-I at km 02+500 and Khalo-II at km 02+750. Reach 2 contains one drain i.e. Qazi Pur at km 08+000. Reach 3 has two drains i.e. Bada Khawar at km 11+500 and Ghurghusti Nullah at km 14+000. In range 4, there is no any sort of drain fall ining the river that ‘s why it is named as plane range. In range 5, there is merely one drain i.e. Badri Khawar at km 29+000. Reach 6 besides contains one drain known as Lahor Drain at km 33+000. The last range No. 7 has two drains i.e. Todhar Drain at km 36+500 and Chel Nullah at km 37+000.

Table 4. Distribution of Study Reach into Different Computational Elementss

Reach No.

Reach Name

Distance Covered ( kilometer )

1

Ghazi-Khalo Reach

0 to 5

2

Qazi Pur Reach

5 to 10

3

Bada-Ghurghusti Reach

10 to 15

4

Plane Reach

15 to 25

5

Badri Reach

25 to 30

6

Lahor Reach

30 to 35

7

Todhar-Chel Reach

35 to 41

3.1 Model Calibration

The theoretical account was calibrated for low flow utilizing river discharge informations during January.

The effluent discharges were taken for the same month of January. The selected H2O quality parametric quantities, i.e. DO and BOD were used to imitate for the selected range of the river. The theoretical account was made to run merely for low flow discharge because at high flow there would be insignificance consequence on H2O quality of the river flood plain from initiation of the effluent wastewaters as river flows will be really high to thin these pollutions. So the theoretical account was non calibrated for high flow discharge.

The mean discharge observed during January in the river flood plain was 297 cumecs ( 10,500 cusecs ) , which was used for theoretical account standardization. The DO and BOD values at 30 thousand d/s of different point beginnings observed during January that were used to compare the theoretical account out put values for standardization intents are given in Table 5.

Table 5. Water Quality Parameters at 30 thousand D/S of Different Point Sources in the Study Area

Site

DO ( mg/l )

BOD ( mg/l )

Ghazi

8.6

6.0

Khalo

7.8

6.0

Bada Khawar

7.5

3.3

Lahor

8.7

3.0

Chel

8.5

1.5

Beginning: WAPDA

The informations used for mode standardization included DO, BOD, H2O temperature and other H2O quality parametric quantities provided in Table 3. The other chief informations used for theoretical account standardization was:

Bed Slope 0.002 m/m ( as there is a bead of 76 m in a range of 63 kilometers, WAPDA, 2003 ) .

Maning ‘s ‘n ‘ 0.1 ( as recommended in “ Documentation and Users Manual ” for natural watercourses ) .

Average air current speed in the month of January 1.28 m/s ( WAPDA, 2003 ) .

Upstream and Downstream Latitude and Longitude values of ranges ( Atlas of Pakistan, 1992 ) .

Average Hourly air temperature for the month of January as 13.70 Co ( WAPDA, 2003 ) .

Shade values were taken zero per centum as per site conditions and users manual recommendations.

Bottom Algae was taken as 20 per centum as per site conditions and theoretical account manual instructions.

Cloud Cover was taken as 25 per centum as per site conditions and theoretical account manual instructions.

The theoretical account was made to run for standardization intents by choosing the other parametric quantities to be used by the theoretical account as per guidelines provided in the manual for the theoretical account users. The comparing of DO and BOD values observed through sampling and calculated by theoretical account at locations indicated in Table 5 is presented in Table 6.

Table 6. Comparison of Observed and Calculated DO and BOD Values at Different locations in the survey country

Location

Observed DO

( mg/l )

Calculated DO

( mg/l )

Observed BOD ( mg/l )

Calculated BOD ( mg/l )

Ghazi

8.6

8.55

6.0

5.38

Khalo

7.8

8.50

6.0

5.30

Bada Khawar

7.5

8.27

3.3

4.46

Lahor

8.7

7.50

3.0

2.98

Chel

8.5

7.30

1.5

2.58

Average

8.22

8.02

3.9

4.14

Average Deviation in DO:

Avg. DO Deviation = ( Avg. Observed DO – Avg. Calculated DO ) * 100

Avg. Observed DO

= ( 8.22-8.02 ) *100

8.22

= +2.4 %

Similarly,

Average Deviation in BOD:

Avg. BOD Deviation = ( Avg. Observed BOD – Avg. Calculated BOD ) * 100

Avg. Observed BOD

= ( 3.9 – 4.14 ) * 100

3.9

= – 6.1 %

3.2 Appropriate Water Quality Criteria

One of the of import parametric quantity associating to the river H2O quality is dissolved O. Aquatic life will be adversely affected if the dissolved O is non within the prescribed bounds or there is inordinate concentration of heavy metals. However, the effluent quality consequences show that there is no important part of heavy metals. Therefore, the determination to be based on DO concentration, lower limit and non on mean concentrations arises from assorted considerations. Deleterious effects on fish seem to depend more on extremes than on norms. For illustration, the growing of immature fish is shown markedly if the O concentration falls to 3 mg/l for portion of the twenty-four hours, even if it rises every bit high as 8 mg/l at other times ( Bahzad, 2002 ) .

The Australian Water Quality Guidelines proposes that DO should non be permitted to fall below 6 mg/l or 80-90 % impregnation ( Bahzad, 2002 ) , this being determined over at least on diurnal rhythm. This figure is recommended based on the surveies conducted in Victoria Australia, which showed that DO concentrations below 5 mg/l are nerve-racking to many specifies. The experts recommend that a DO concentration of 4mg/l should be maintained in the fresh H2O watercourses because the aquatic life is moderately protected at 4 mg/l ( Bahzad, 2002 ) . To keep the DO degree within allowable bound, it is desirable that BOD concentration in river H2O be kept low. The European Community has given a maximal BOD bound for aquatic life ( peculiarly fish ) as 3.0 to 6.0 mg/l where as USSR criterions are rigorous and let a maximal BOD of 3 mg/l merely ( Bahzad, 2002 ) .

Pakistan Environmental Protection Agency ( EPA ) has no upper limit and minimal bounds of DO and BOD for aquatic life as such. But it is limitation from EPA that the effluent should be treated to convey BOD of the wastewaters up to 80 mg/l before dispatching it into natural watercourse when adequate H2O is available for its dilution by 10 times.

Based on above treatments, BOD values were taken in the fury of 8 mg/l and DO should non be less than in 4 mg/l for the intent of simulation of different scenarios.

3.3 Model Simulations

Scenario -1: In this scenario, the present status i.e. in twelvemonth 2002 has been checked when there will be minimal flow of 28 cumecs ( 990 cusecs ) . The effluent discharges with their DO and BOD inputs are shown in Table 7.

The H2O quality informations was non available for a figure of drains/ nullahs. So H2O quality informations for the drains like Ghazi-M, Khalo-I, Khalo-II and Qazipur were assumed to be of similar nature as measured in instance of Ghazi-I Drain. Similarly, for Lahore and Todhar drains, H2O quality was assumed to be the same as in instance of Badri Khawar. While in instance of Bada Khawar Nullah, the H2O was non available at the clip of H2O discharge measurings in January 2002. However, two industrial estates Gadoon-Amazi Eastern and Gadoon-Amazi Western are disposing of their effluent into Bada Khawar Nullah at a distance of about 13 Km upstream of its outfall into the Indus River. For appraisal under inauspicious status the discharge every bit good as effluent quality informations was used which was the amount of both industrial estates for Bada Khawar presuming that all effluent is dispatching into the river.

It may be noted that theoretical account allows the simulation of two signifiers of carbonous BOD to stand for organic C. These signifiers are a easy oxidizing signifier ( CBODs ) and a quickly oxidizing signifier ( CBODf ) . Since, there are no separate values for CBODs and CBODf, so the BOD values alternatively of CBODs ( presuming that it besides covers the clip of fast oxidising stuff ) are used. Hence the theoretical account end product values for CBODs are the stand foring values of the BOD. The consequences of Scenario-1 are given in Table 8.

Scenario -2: In this scenario the river flow was the same as 28 cumecs but the discharge of the darins/nullahs was projected for the twelvemonth 2063. The ground for projection of the effluent discharge upto the twelvemonth 2063 was that the undertaking life of Ghazi Brotha Hydropower is for 60 old ages. The quality of the effluent was assumed to be the same as in Scenario 1. The jutting effluent measure and quality used for theoretical account input in Scenario- 2 is given in Table 7. The consequences of this scenario are given in Table 8.

Scenario -3: This scenario was the same as Scenario-2 with lone difference that the BOD of effluent was assumed to falling in the scope of 80mg/l in undertaking life, which is the worst instance. The premise for BOD upto 80 mg/l was based on the EPA limitation that the effluent should be treated upto 80 mg/l BOD before dispatching it into the natural steam and natural watercourse should has the discharges for 10 times dilution. The jutting effluent discharge for the twelvemonth 2063 and quality of the effluent used for theoretical account input in Scenario-3 is given in Table 7. It may be noted that the BOD value was taken for Bada Khawar is the same as in instance of Scenarios-1 and 2 due to ground that it is already over 80 mg/l i.e. 111.5 mg/l. The consequences of this scenario are given in Table 8.

Table 7. Wastewater Discharge and Water Quality informations used for Model input

under Selected Scenarios- 1,2 & A ;

Site

Scenario-1

Scenario-2

Scenario-3

Discharge for the twelvemonth 2003

( cumecs )

DO Model Input

( mg/l )

BOD Model Input

( mg/l )

Discharge for the twelvemonth 2063*

( cumecs )

DO Model Input

( mg/l )

BOD Model Input

( mg/l )

Discharge for the twelvemonth 2063

( cumecs )

DO Model Input

( mg/l )

BOD Model Input

( mg/l )

Ghazi-I

0.0024

3.9

66

0.0086

3.9

66

0.0086

3.9

80

Ghazi-M

0.0038

3.9

66

0.0135

3.9

66

0.0135

3.9

80

Khalo-I

0.0005

3.9

66

0.0042

3.9

66

0.0042

3.9

80

Khalo-II

0.0005

3.9

66

0.0042

3.9

66

0.0042

3.9

80

Qazipur

0.002

3.9

66

0.0110

3.9

66

0.0110

3.9

80

Ghurghushti

0.347

6.3

15.7

0.8632

6.3

15.7

0.8632

6.3

80

Chel

0.245

6.9

6.0

1.156

6.9

6.0

1.156

6.9

80

Bada Khawar

0.071

5.2

111.5

0.071

5.2

111.5

0.071

5.2

111.5

Badri Khawar

2.25

7.9

4.5

2.707

7.9

4.5

2.707

7.9

80

Lahor Drain

0.375

7.9

4.5

0.545

7.9

4.5

0.545

7.9

80

Todhar Drain

0.126

7.9

4.5

0.3006

7.9

4.5

0.3006

7.9

80

*Source: WAPDA.

3.3 Consequences of the Scenarios

Table 8 depicts the consequences of Scenarios 1, 2 and 3 for values of DO and BOD.

Table 8: Comparison of the Results of Scenarios 1, 2 & A ; 3

Reach Label

Distance

( kilometer )

Scenario 1

Scenario 2

Scenario 3

Make

( mg/l )

Human body

( mg/l )

Make

( mg/l )

Human body

( mg/l )

Make

( mg/l )

Human body

( mg/l )

Barrage

0.00

8.60

6.00

8.60

6.00

8.60

6.00

Ghazi-Khalo

2.50

8.84

4.67

8.84

4.71

8.83

4.72

Qazipur

7.50

8.90

3.65

8.89

3.69

8.89

3.71

Bada-Ghurghushti

12.50

8.67

3.37

8.61

3.58

8.54

5.18

Plan

20.00

8.75

2.27

8.69

2.41

8.45

3.47

Badri

27.50

8.65

2.63

8.57

2.17

8.04

8.30

Lahor

32.50

9.00

1.64

8.93

1.75

8.05

7.36

Todhar-Chel

38.00

9.27

1.33

9.16

1.50

7.89

7.81

Tail

41.00

9.27

1.33

9.16

1.50

7.89

7.81

As clear from above tabular array that the DO values are about same in first two Scenarios and there is a minor fluctuation in instance of Scenario-3. The DO values are much higher than allowable bounds of 4 mg/l, so it can be assumed that there will be no danger to aquatic life due to handiness of DO in river even during reduced flow, projected effluent for the twelvemonth 2063 and worst BOD of sewerage up to 80 mg/l.

In instance of BOD, the values are same in Scenarios-1 and 2. However, the values are higher in instance of Scenario- 3 as compared to other two scenarios. But the values are about within allowable bound of 8 mg/l for reduced flow, projected effluent discharges and worst status of BOD up to 80 mg/l. So, based on above consequences it can be assumed that there will be no inauspicious consequence on aquatic life of the river during life of the Ghazi Brotha Hydropower Project.

4. Remarks and Discussions

Model DO Output Values

It may be observed from Table 9 that the DO values from bombardment to downstream are in the scope of 8.60 mg/l to 7.90 mg/l, which are about same as compared to general observations made through sampling as provided in Table 3. As per Table 3, the DO values are 8.6 mg/l at bombardment and downstream of Chel Nullah i.e. 8.5 mg/l. It may be noted that at reduced flow of 28 cumecs, projected effluent measure and worse effluent quality of upto 80 mg/l BOD, the theoretical account out put DO and observed DO by trying are about same which may be due to ground that the decreased H2O flow form in the river was taken as the same as ascertained during October 2002 to May 2003 at the clip of river study when the flow was changing from 297 cumecs to 770 cumecs. Since it was assumed that at decreased flow conditions the H2O will flux in the same brook as observed in river study of October 2002 to May 2003, the cross sectional country of the reduced flow is presumptively more and deepness of flow is lesser than the existent status that will predominate when the discharges of the river are 28 cumecs. Ultimately, the opportunity of re-aeration, O inhabitancy, photo-synthetically available radiation is more than the existent, therefore the values of DO have increased consequently. Basically, it is non possible to foretell exact way of flow, which will be followed by the reduced flow, it may necessitate a elaborate hydraulic theoretical account survey.

Model BOD Output Values

It may besides observed from Table 9 that the BOD value is higher at downstream of bombardment i.e. 6 mg/l and it goes on diminishing farther downstream and it remains as 1.85 and 1.86 mg/l in Scenarios 1 & A ; 2 and 7.81 mg/l in Scenario 3, even though there are a figure of drains/nullahs dispatching their wastewaters into the river. This state of affairs may be due to several grounds. One chief ground is that at upstream of the bombardment there are three chief sewerage outfalls on Left Bank, which are dispatching pollutants of Main Terbela Colony, Sanober Colony and Sobra City of WAPDA into the river. Similarly, on Right Bank there are two sewerage outfalls, which are lending the pollutants of Powerhouse Colony WAPDA and GIK Institute. All these settlements and institute have their outflowing intervention workss and it is assumed that the BOD value of the pollutants will be in the scope of 80 mg/l. The 2nd ground of the bombardment side, higher value of the BOD may be due to dead H2O of the impoundment country as it has less opportunity of re-aeration and radiation due to higher deepness of the H2O. Third, the ground for less value of BOD on downstream side is that the measures of the wastewaters are little and their quality is non much deteriorated. However, in instance of scenario-3 where the BOD value of effluent quality was assumed to be in the scope of 80mg/l, the BOD value of river flood plain is higher than that at bombardment. Fourthly, the riverbed downstream is largely soberly therefore a batch of turbulency is encountered in the flows, which consequences effectual assimilation of pollutants.

Premises of Scenario- 3

At simulation of Scenario- 3, it was assumed that the BOD of effluent would be in the scope of 80 mg/l as per EPA criterions. This will be the instance if the effluent is treated consequently before dispatching it into the river. The samples collected at the clip of Feasibility Study at Ghazi and Khalo drains were demoing that the value of BOD was over 400mg/l. During last few old ages, the local population has constructed infected armored combat vehicles and soaking cavities in their houses, due to this installation the quality of effluent is comparatively better. But finally the capacities of the infected armored combat vehicles and soaking cavities will be over and so the quality of effluent may once more deteriorate. The local disposal is supplying proper flush systems even to the rural countries. If such flush system was provided in the survey country, the quality of effluent will further deteriorate and it may traverse the scope of 80mg/l as assumed in Scenario-3. So there will be need of some extenuation and direction program to maintain the BOD within allowable bounds.

Some drains/nallas e.g. Ghurghashti, Chel, Bada Khawar and Badri Khawar, carry effluent from far off and most of the H2O do non make up to the river due to seepage into the land and causes the land H2O taint. If in these villages/towns, which are lending their effluent into these near by drains/nullahs were besides provided the flower system and the drains were lined, the part of effluent of these drains will be much higher to the river as assumed in the Scenario-3. Due to higher H2O measure and worst quality of the drains/nullahs effluent, the quality of the river H2O may deteriorate. So there will be a demand of some direction program for effluent intervention of those villages/towns, which are even far off from the river but may impact the river H2O quality.

Future Industrial Development of the Area

Local Development Authority is be aftering to develop an Industrial Estate about 5 kilometers downstream of the Ghazi small town. For this intent the basic substructure has already been developed by the Local Development Authority. If this industrial estate is developed, its effluent will besides impact the river H2O quality. So there will be need of some direction program to salvage the river H2O quality from farther impairment.

5. Decisions and Recommendations

5.1 Decisions

Based on the theoretical account consequences and treatments, the undermentioned decisions are derived.

Under present conditions of quality and measure of effluent and minimal flow of

28 cumecs, the DO and BOD remain within allowable bounds.

Under minimal flow conditions of 28 cumecs and projected effluent measure for the twelvemonth 2063, the DO and BOD values will stay within the allowable bounds.

Under minimal flow conditions, projected effluent for the twelvemonth 2063 and assumed wastewater quality in the scope of 80 mg/l, the DO and BOD values will still stay within the allowable bounds.

The flow form of the minimal flow in the river may necessitate to be established to obtain the exact values of the DO and BOD in all three scenarios.

When capacities of the infected armored combat vehicles and soaking cavities are over in the concerned towns/villages, the quality of the effluent is apt to farther deteriorate by traversing the bound of 80 mg/l. Under such scenarios, some extenuation and direction program will be required to maintain the river H2O quality within allowable bounds.

By supplying flush system for the families in the concerned towns/villages, if the drains/nullahs transporting the sewerage H2O to the river are lined, the measure of the effluent will increase, ensuing in an addition in pollution degree. Therefore, in the direction program, this facet will be required for consideration.

If the Local Development Authority develops an Industrial Estate at 5 km downstream of Ghazi, the effluent from Industrial Estate may farther deteriorate the river H2O quality and therefore necessitate some extenuation and direction program.

5.2 Recommendations

With mention to above decisions, the undermentioned recommendations are made to set up the river flow form to extenuate the inauspicious effects and measure the direction plans to guarantee that the river H2O quality may stay within the allowable bounds.

Hydraulic Model Study: It is recommended that a proper Hydraulic Model Study should be conducted to set up the river flow form during the reduced flow. It will assist measure the values of DO and BOD near to practical state of affairs and find the brook which will be independently affected due to cut down flow.

Wastewater Treatment Facilities: In order to maintain the BOD values of the wastewaters in the scope of 80 mg/l in the undertaking life, the intervention installations like intervention workss for large cities/towns and oxidization pools for comparatively little towns may be provided. Similarly the option for the proviso of Reed-Bed Lagoons and Reed-Bed Channels may besides be adopted, as it proved to be really economic and effectual solution.

Release of Excessive sum of Water from Barrage to the River: If the Industrial Estate was constructed by the Local Development Authority, so a sophisticated effluent intervention works, to maintain the BOD less than 80 mg/l, will be required to extenuate the effects on H2O quality of the Indus River flood plain.

Mentions and Notes

Atlas of Pakistan, ( 1992 ) . Survey Sheet No. 24, Survey of Pakistan, Murree Road, Rawalpindi, published in1992.

Bahzaz, A. , ( 2002 ) , “ Application of QUAL2K Model to the Contaminant Transport in River Ravi ” , M.SC ( WRM ) Thesis, Centre of Excellence in Water Resources Engineering, UET, Lahore.

Brown, L.C. , and T.O. Barnwell, ( 1987 ) . The Enhanced Stream Water Quality Model QUAL2E and QUAL2E-UNCAS, EPA/600/3-87-007, U.S. Environmental Protection Agency, Athens, G. A.

PHC ( Pakistan Hydro Consultants ) , ( 1992 ) . Ghazi-Brotha Hydropower Project, “ Report on Supplementary Environmental Studies ” .

PHC ( Pakistan Hydro Consultants ) , ( 1991 ) , Feasibility Report, “ Environmental Assessment of Ghazi-Gariala Hydropower Project ” , Volume 7.

Steve, C. and Greg. P. , ( 2003 ) . QUAL2K, A Modelling Framework for Simulating River and Stream Water Quality “ Documentation and Users Manual ” .

WAPDA, ( 2003 ) . Ghazi-Brotha Hydropower Project, “ Auxiliary Environmental and Social ( SES ) Study for Management of Indus Flood Plain and Water Releases ” ( 2003 ) .

A© 2010 by the writers ; licensee MDPI, Basel, Switzerland. This article is an open-access article distributed under the footings and conditions of the Creative Commons Attribution licence ( hypertext transfer protocol: //creativecommons.org/licenses/by/3.0/ ) .

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