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CHAPTER 2
STUDY AREA
2.1 INTRODUCTION
The river Noyyal is one of the small tributary of river Cauvery. This
river originates at Vellingiri hills of Western Ghats. The Noyyal River flows
through downstream side of Tiruppur town for about 32 Km to Orathupalayam
dam, which was constructed during 1992. There are 729 dyeing and bleaching
industries are functioning in Tiruppur. The Noyyal river water has been
indiscriminately polluted due to continuous, uncontrolled and partially treated
discharge of effluent from dyeing and bleaching industries and untreated
domestic sewage. This has also spoiled the groundwater adjacent to the river
and in and around Orathupalayam dam. The four system tanks located below
Tiruppur have become storage of effluent. The good number of flora and fauna
are slowly getting disappeared in Tiruppur area. Farmers are not using this
water for irrigation purposes. Cattle also avoid drinking of this water. People
are not using this water for any other purposes. Many studies have been done
by individuals and by institutions, in Tiruppur regarding the impact of dyeing
and bleaching effluent in Noyyal river. All those studies were independent and
but many aspects are not yet studied. Particularly the remediation of sediment
in the Orathupalayam dam site.
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2.2 ENVIRONMENTAL DEGRADATION OF
ORATHUPALAYAM DAM
2.2.1 Salient Features of Orathupalayam Dam
Noyyal reservoir scheme extension proposal envisages utilization of
the flood water occurring in the river Noyyal during north east monsoon and
south west monsoon periods (Environmental Cell Division, PWD, 2008).
During north east monsoon period the intensity of flood is heavy when the
Cauvery delta is facing drainage problem. The extension proposal
contemplates a storage reservoir across Noyyal river near Orathupalayam
village with a capacity of 17.44 mm3 (616 M.Cuft). Accordingly, the Public
Works Department in year 1982 decided to construct Orathupalayam dam with
a capacity of 17.44 mm3 (616 Mcft) with left an right side canal for irrigating
dry lands of 500 acres in Perunthurai and Kangeyam taluks of Erode district
(Table 2.1). Noyyal river basin is shown in Figure 2.1
Tiruppur
Noyyal
River
NCauvery. R
CETP
RiverSamplingLocation
OrathupalayamDam
Schematic Diagram of Noyyal River Basin
Figure 2.1 Location of Noyyal River Basin, Tiruppur CETPs
23
Table 2.1 Salient Features of Orathupalayam Dam
Basin Cauvery Basin
Sub Basin Noyyal river basin
Capacity 17.44 mm3 (616 Mcft)
Ayacut (irrigation area) 500 acres
Catchment area 2245.55 sq.km
Yield 89245 Cusecs
No. of filling 2
F.R.L (amsl) 248 m
Max. water level (amsl) 248 m
Top of bund level 250.1 m
Total length of dam 2.29 Km
Surplus arrangements During flood season
i). River sluice will be opened
ii). The radial shutter will be opened
No. of sluices i). River sluice – 2 Nos.
ii) Irrigation sluice – 2 Nos.
Sill level of the sluices (amsl) River sluice - 236 m
Irrigation sluice - 245 m
Total length of canal Left side canal – 1.40 Km
Right side canal – 1.86 Km
Capacity of the canal Left side canal - 3 Cusec
Right side canal - 8 cusec.
Source: ECD, PWD, 2008
2.2.2 Pollution to Orathupalayam Dam
The Orathupalayam dam was completed during 1992. Farmers
expects for adequate and good quality water for irrigation. But the cluster of
industries in Tiruppur entered into international market due to liberalization of
trade rules. The bleaching and dyeing industries were the backbone of the
24
knitting export industries. During 1990 the bleaching and dyeing industries did
not have effluent treatment plants and the untreated effluent released with
Noyyal water lead to serious changes in the physio-chemical characteristics of
surface water of Noyyal river upto Orathupalayam dam.
The bleaching and dyeing industries in Tiruppur area generate huge
quantities of wastewater (effluent) and for the treatment chemical method is
being adopted by adding ferrous sulphate and lime which removes colour and
reduces BOD, COD effectively. But the salt content present in the form of
TDS is not reduced but enhanced by it. This partially treated effluent,
discharged into the Noyyal river, has high TDS of 5000 mg/L to 6000 mg/L
that ultimately stored in Orathupalayam dam. The dam water is coloured with
oily layer on top. The TDS and chloride concentrations are higher than
irrigation standards except in the rainy seasons. The farmers from Karur
district raised their objections and filed a writ petition in the High Court of
Madras.
Due to this semi treated effluent discharged into the Noyyal river
and stored in the dam, the entire river eco system below Tiruppur and in and
around Orathupalayam dam has been damaged. The surface water, ground
water, soil and land have been all degraded. No agriculture activities take
place here. Hence the very purpose of Orathupalayam dam is defeated. The
water samples (both bore and open wells) analysis in Tiruppur region based on
drinking water standards reveal that water is unfit for drinking in many areas.
The fisheries unit at Orathupalayam dam was closed during 1997 due to mass
fish mortality. Fishing in Noyyal River and its system tanks have decreased.
With the prevailing water scarcity, the restoration of Orathupalayam dam is
the need of the hour. The restoration of Orathupalayam wholly depends on
including change of current effluent treatment technology.
25
2.3 TEXTILE DYEING UNITS
In Tiruppur, there are 729 bleaching and dyeing units under
operation (TNPCB, 2008). These units process mainly hosiery cloth and cotton
cloth. The process is water intensive. The process flow chart is given Figure
2.2. The process involves bleaching, neutralizing, washing, dyeing, washing,
acid wash, washing, soaping, hot wash, and fixing and softening. The quality
of wastewater generated by these operations mainly depends on the chemicals
used and the processes adopted. 100 kg of fabric bleaching and dyeing process
generate 800 litres of trade effluent from soft flow machine process, and 1500
litres from winch machine process. Each unit discharges about 150 kilo litres
per day (KLD) of effluent. In total the units in Tiruppur discharge about 96.1
MLD of effluent. Raw effluent characteristic is given in Table 2.2.
Figure 2.2 Process Flow Chart of a Bleaching and Dyeing Industry
Raw Fabric Bleaching Neutralizing Washing Dyeing
Washing Acid wash Washing Soaping Hot wash
Fixing & Softening Finished Fabric
26
Table 2.2 Raw Effluent Characteristic of the Combined Effluent from
Dyeing Process
S.No. Parameter Range Discharge standards
for inland surface
water (TNPCB)
1 pH 6 - 10 5.5 - 9
2 Temperature 35 – 45oC 40
oC at the point of
discharge
3 Total dissolved solids 8000 - 12000 mg/L 2100 mg/L
4 Bio-chemical oxygen demand 300 – 500 mg/L 30 mg/L
5 Chemical oxygen demand 1000 – 1500 mg/L 250 mg/L
6 Total suspended solids 200 – 400 mg/L 100 mg/L
7 Chloride 3000 – 6000 mg/L 1000 mg/L
8 Sulphate 600 – 1000 mg/L 1000 mg/L
9 Oil & Grease 10 – 30 mg/L 10 mg/L
10 Percent Soluble Sodium 70 - 80 60 (permissible
level for irrigation)Source: TNPCB, 2008
Note: Percent Soluble Sodium (PSS) = 10022
X
KNaMgCa
Na
2.3.1 Effluent Treatment Plants
In Tiruppur, the large and medium scale units (236 units) have
provided individual effluent treatment plant (IETP). The treated effluent is
used on land of irrigation in industries own land and the excess effluent is
discharged in to river Noyyal. The remaining medium and small scale units
(493 units) who have not adequate land and finance to provide IETP, have
joined together and formed company. Through the company, they executed
common effluent treatment plants (CETP) with 50% finical subsidies from
Central and State Governments. 8 CETPs were installed. Out of these one
CETP was defunct. The treatment system generally consists of collection well,
equalization tank, flash mixer, clariflocculator, aeration tank, clarifier, pressure
sand filter, sludge thickener, centrifuge, and sludge drying beds. After
27
treatment the treated effluent was discharged into river Noyyal. In this study,
the quality of the CETPs discharge and the water quality of river Noyyal and
Orathupalayam dam are presented. Since the pollutant transported and gets
settled in the dam, the dam sediment is also analyzed and presented.
Figure 2.3 Flow Diagram of CETP
2.3.2 Quality of CETP Discharge
TNPCB monitors the quality of CETP discharge on monthly basis
by collecting grab sampling. For this study purpose, 12 hours composite
effluent samples were collected every month at the out lets of 7 CETPs from
April 2008 to March 2009. The samples were collected in 2.5 litre new clean
plastic containers and transported to TNPCB Tiruppur District Environmental
laboratory in the same day. The samples were stored at 4oC and analysed
within a week’s time. The samples were analyzed as per the standards methods
of APHA (2005). The analysis was carried out for physico chemical
parameters. The quality of effluent at CETPs outlet is given in Table 2.3. None
of the CETPs met the TDS and chlorides discharge standards. TDS level
varies from 2799 mg/l to 30556 mg/L as against permissible level of 2100
mg/L, chlorides was in the range of 962-14722 mg/L as against the
permissible level of 1000 mg/L. BOD was in the range of 1-300 mg/L as
Raw Effluent Equalization Flash mixing
(Alum & Lime)Flocculation
Clarification Rapid Sand
Filtration
Chemical
Oxidation
Gravity
Thickener
Centrifuge /
Drying beds
Dewatered sludge
for Disposal
Treated Effluent
for Disposal
28
i). Equalization Tank ii). Chemical Mixing Tank
iii) Aeration Tank iv). Clarifier Tank
v). Pressure Sand Filter Tanks vi). Sludge Dewatering Machine
Figure 2.4 Photographs of Treatment Units in a CETP
29
against the permissible level of 30 mg/L, COD was in the range of 49-1975
mg/L as against the permissible level of 250 mg/L, percent soluble sodium
was in the range of 85-98% against permissible level of 60% (on land for
irrigation standards). The results are presented in Figure-2.5 to 2.12.
The conventional activated sludge process with dosing of ferrous
sulphate and lime for pH correction, followed by clarification, filtration will
remove the colour and reduces BOD, and COD. Here the presence of excess
BOD and COD in the CETP outlet is due to improper operation of treatment
plant. Even the treatment plant is operated efficiently and continuously it can
not remove the TDS and chlorides to the desired level. Since a major portion
of the contaminants in the textile water are dye stuffs and sodium chloride
which are non-biodegradable and hence the conventional biological treatment
does not work unless state-of-the-art technologies such as Membrane
Bioreactor (MBR) followed by Reverse Osmosis plant are implemented.
MBR utilizes activated sludge process in combination with membrane
(micro/ultrafiltration) filtration for retention of active micro-organisms and
heavy molecular weight organics typical of textile effluent, where after
colourless effluent is let out. When it passes through RO plant, the TDS is
removed and the permeate can be reused and the high TDS rejects can be
handled in reject management system.
30
Table 2. 3 Quality of CETP Outlet Discharge
S.No
CETP No. ofMember
Units
Plant
Capacity
(KLD)
Parameters Apl‘08
May‘08
June‘08
July‘08
Aug‘08
Sep‘08
Oct‘08
Nov‘08
Dec‘08
Jan‘09
Feb‘09
March‘09
1 Andipalayam 21 4500 pH 8.32 9.4 9.15 7.67 9.23 9.02 8.41 8.45 8.51 9.74 8.42 9.29
BOD 28 10 30 36 60 24 24 32 36 20 24 78
COD 245 131 240 240 448 216 164 600 792 197 192 583
TSS 240 48 136 72 76 156 36 145 152 36 84 156
TDS 7172 6420 7304 8648 6976 7212 6200 7320 6840 5840 7104 7344
Chlorides 3750 3349 4049 4058 3154 3635 3173 4049 3702 3423 3942 3426
Sulphates 444 292 318 325 256 237 397 345 310 198 192 583
% Sodium 91 92 92 93 93 92 94 92 90 97 94 95
2 Angeripalayam 81 10000 pH 7.27 9.51 9.43 7.61 9.44 9.35 9.21 9.38 7.1 6.81 7.45 7.77
BOD 28 1 30 24 24 60 18 20 120 33 72 24
COD 158 49 240 160 208 413 1487 97 932 328 672 224
TSS 152 60 80 20 80 84 32 136 72 148 104 48
TDS 8076 5888 6452 6096 6824 7168 6260 6316 8592 6916 5880 6876
Chlorides 3256 2999 3549 3231 3173 3365 2827 3096 3442 3413 3538 3481
Sulphates 687 684 525 502 413 437 398 508 602 472 428 434
% Sodium 91 92 95 90 94 93 96 92 94 88 93 85
3 Kasipalayam 15 4400 pH 7.99 6.74 10.66 8.62 10.16 7.22 8.5 8.01 7.17 7.77 7.96 7.99
BOD 68 85 120 36 30 14 14 10 10 7 2 2
COD 372 458 686 240 249 138 90 81 73 66 80 49
TSS 52 84 136 120 120 138 3 52 64 72 100 52
TDS 6200 6096 8552 7912 7236 6868 6864 6992 7020 5892 7344 6200
Chlorides 3352 2676 3199 3404 3327 3077 2981 3048 3135 3154 3066 2833
Sulphates 49 64 689 240 249 138 90 81 73 66 80 49
% Sodium 95 92 97 88 96 87 94 90 94 93 91 91
4 Mannarai 29 4200 pH 11.73 10.66 12 8.18 11.14 10.59 11.79 11.2 11.53 11.39 11.41 11.12
BOD 94 120 12 42 48 48 54 68 96 1 42 12
COD 526 689 142 240 354 264 328 524 745 57 376 216
TSS 72 136 112 80 108 100 15 100 128 56 120 80
TDS 3812 8552 6640 6572 8104 5708 6596 6640 4652 4712 7384 4112
31
Table 2.3 (continued)Chlorides 3258 3199 3296 2731 3711 3415 2981 3269 2231 3173 3160 3096
Sulphates 353 626 443 398 467 382 379 350 372 389 325 355
% Sodium 93 97 87 94 98 99 98 95 97 98 98 98
5 Chinnakarai 31 8000 pH 9.24 8.86 8.82 6.39 8.49 8.23 8.26 7.72 7.79 8.22 8.01 9.14
BOD 30 42 12 6 6 28 34 300 2 2 3 30
COD 243 365 98 57 33 194 351 1975 16 25 72 243
TSS 108 148 244 180 24 108 152 192 52 72 96 244
TDS 6768 7236 5288 2868 4850 5736 3000 5736 6764 2976 6544 30556
Chlorides 3549 3000 2799 1231 962 3000 2799 2135 3135 1404 3654 14722
Sulphates 311 126 274 49 97 159 185 232 546 238 474 1248
% Sodium 91 93 94 87 85 92 86 95 90 92 94 96
6 Kunnangalpalayam 19 5500 pH 6.53 7.38 7.86 9.25 9.4 9.2 9.1 7.72 8.65 6.35 7 7.76
BOD 48 18 12 24 42 84 120 180 36 2 2 4
COD 405 122 74 162 384 427 634 948 284 25 24 32
TSS 436 100 100 204 100 108 90 60 60 64 96 128
TDS 6100 4512 6364 6096 10804 6150 6364 6092 6468 5108 5344 14308
Chlorides 3599 2199 2799 2500 4000 2199 2799 2529 2788 2596 2596 7111
Sulphates 400 280 389 523 314 509 485 409 295 436 448 628
% Sodium 89 94 92 91 94 90 93 93 91 94 96 95
7 Veerapandi 73 12000 pH 8.88 7.65 9.65 9.15 8.9 8.5 9.2 7.69 9.96 8.82 8.99 9.53
BOD 30 12 24 45 52 32 28 84 36 36 18 12
COD 243 82 197 215 351 295 280 713 243 287 176 138
TSS 64 72 144 152 190 215 97 52 100 112 72 92
TDS 6236 6832 7512 6240 7250 6832 7512 6388 6460 7176 7376 5824
Chlorides 3199 3699 3849 2951 2880 4630 3849 2259 2971 3135 3010 2750
Sulphates 583 321 523 563 593 478 568 615 673 527 684 633
% Sodium 92 97 92 94 92 90 89 94 96 90 98 98
All Parameters are in mg/L except pH, % Sodium. TNPCB effluent discharge standards for inland surface water bodies : pH 5.5-9, BOD 30 mg/L,
COD 250 mg/L, TSS 100 mg/L, TDS - 2100 mg/L, Chlorides - 1000 mg/L, Sulphates – 1000 mg/Land % sodium for irrigation 60 (max. limit)
32
0
2
4
6
8
10
12
14A
pr'08
May'0
8
Jun'0
8
Jly
'08
Aug'0
8
Sep'0
8
Oct'08
Nov'0
8
Dec'0
8
Jan'0
9
Feb'0
9
Mar'09
Month
pH
Andipalayam Angeripalayam Kasipalayam
Mannarai Chinnakarai Kunnangalpalaym
Veerapandi Lower Limit Upper Limit
Figure 2.5 pH Profile of Tiruppur CETPs Discharge
0
50
100
150
200
250
300
350
Ap
r'0
8
Ma
y'0
8
Ju
n'0
8
Jly
'08
Au
g'0
8
Se
p'0
8
Oc
t'0
8
No
v'0
8
De
c'0
8
Ja
n'0
9
Fe
b'0
9
Ma
r'0
9
Month
BO
D m
g/L
Andipalayam Angeripalayam Kasipalayam
Mannarai Chinnakarai Kunnangalpalaym
Veerapandi Standard
Figure 2.6 BOD Profile of Tiruppur CETPs Discharge
33
0
500
1000
1500
2000
2500
Apr'08
May'0
8
Jun'0
8
Jly
'08
Aug'0
8
Sep'0
8
Oct'08
Nov'0
8
Dec'0
8
Jan'0
9
Feb'0
9
Mar'09
Month
CO
D m
g/L
Andipalayam Angeripalayam Kasipalayam
Mannarai Chinnakarai Kunnangalpalaym
Veerapandi Standard
Figure 2.7 COD Profile of Tiruppur CETPs Discharge
0
50
100
150
200
250
300
350
400
450
500
Apr'08
May'0
8
Jun'0
8
Jly
'08
Aug'0
8
Sep'0
8
Oct'08
Nov'0
8
Dec'0
8
Jan'0
9
Feb'0
9
Mar'09
Month
TS
S m
g/L
Andipalayam Angeripalayam Kasipalayam
Mannarai Chinnakarai Kunnangalpalaym
Veerapandi Standard
Figure 2.8 TSS Profile of Tiruppur CETPs Discharge
34
0
2000
4000
6000
8000
10000
12000
14000
Apr'08
May'0
8
Jun'0
8
Jly
'08
Aug'0
8
Sep'0
8
Oct'08
Nov'0
8
Dec'0
8
Jan'0
9
Feb'0
9
Mar'09
Month
TD
S m
g/L
Andipalayam Angeripalayam Kasipalayam
Mannarai Chinnakarai Kunnangalpalaym
Veerapandi Standard
Figure 2.9 TDS Profile of Tiruppur CETPs Discharge
0
1000
2000
3000
4000
5000
6000
Apr'08
May'0
8
Jun'0
8
Jly
'08
Aug'0
8
Sep'0
8
Oct'08
Nov'0
8
Dec'0
8
Jan'0
9
Feb'0
9
Mar'09
Month
Chlo
ride m
g/L
Andipalayam Angeripalayam Kasipalayam
Mannarai Chinnakarai Kunnangalpalaym
Veerapandi Standard
Figure 2.10 Chloride profile of Tiruppur CETPs discharge
35
0
200
400
600
800
1000
1200
Apr'08
May'0
8
Jun'0
8
Jly
'08
Aug'0
8
Sep'0
8
Oct'08
Nov'0
8
Dec'0
8
Jan'0
9
Feb'0
9
Mar'09
Month
Su
lph
ate
mg
/L
Andipalayam Angeripalayam Kasipalayam
Mannarai Chinnakarai Kunnangalpalaym
Veerapandi Standard
Figure 2.11 Sulphate profile of Tiruppur CETPs discharge
0
500
1000
1500
2000
2500
Apr'08
May'0
8
Jun'0
8
Jly
'08
Aug'0
8
Sep'0
8
Oct'08
Nov'0
8
Dec'0
8
Jan'0
9
Feb'0
9
Mar'09
Month
% S
od
ium
Andipalayam Angeripalayam Kasipalayam
Mannarai Chinnakarai Kunnangalpalaym
Veerapandi Standard
Figure 2.12 % Sodium profile of Tiruppur CETPs discharge
36
2.3.3 Zero Liquid Discharge Plant
The textile bleaching and dyeing units in Tiruppur are not able to meet
the TDS discharge standard of 2100 mg/L. The discharge of high TDS effluent
caused a severe damage to the Noyyal river and Orathupalayam dam. The Noyyal
Farmers Association filed a writ petition in the High Court of Madras with a
prayer for compensation to damage caused to the crop and their land. In this
matter, the Hon’ble High Court directed the industries to adopt zero liquid
discharge (ZLD) and recycle the treated effluent. Accordingly the CETPs in
Tiruppur have provided ZLD plant. They are in operation since January 2010.
The flow chart of zero liquid discharge plant is given in Figure 2.13. The
photographs of ZLD plant is given in Figure 2.14
Figure 2.13 Flow chart of Zero Liquid Discharge Plant
Secondary
Treatment
Pressure sand
filter
Activated
carbon filer
RO plant
Mechanical Vacuum
Recompressor
Crystallizer
Centrifuge Solar Pan
Salt recovered – Secured
landfill facility
Permeate for
reuse
Condensate for reuse
37
i). PSF & ACF units ii). RO Plant
iii). Mechanical Vacuum Recompressor iv). Salt Recovery unit
v). Sludge stock in CETP vi). Secured Land Fill Facility
Figure 2.14 Photographs of Zero Liquid Discharge Plant
38
2.3.4 Noyyal River Water Quality
In order to know the Noyyal river water quality, samples were
collected at three locations (i.e). Mangalam (2 km upstream of Tiruppur),
Kasipalayam (5km down stream of Tiruppur) and Anaipalayam (20 km down
stream of Tiruppur). Similarly water samples were collected at Orathupalayam
dam (32 km down stream of Tiruppur) every month (i.e) from April 2008 to
March 2009. The river water samples were taken from 0.3 metres below the water
surface. The samples were collected in 2.5 litre new clean plastic containers and
transported to TNPCB Tiruppur District Environmental laboratory in the same
day. The samples were stored at 4oC and analysed within a week’s time. The
samples were analyzed as per the standards methods of APHA (2005). The
analysis was carried out for physico chemical parameters.
The quality of Noyyal river water (Table 2.4) reveals that the TDS
level in the upstream of Tiruppur was in the range of 900-5336 mg/L. At 5 km
down stream of Tiruppur TDS was in the range of 1716 - 5868 mg/L and at 20
km down stream it was measured in the range of 1372-6636 mg/L. The
permissible level of TDS in Class-C water bodies is 1500 mg/L . Chlorides in the
upstream was in the range of 233-2547 mg/L. At the 5km down stream chlorides
was in the range of 808-2327 mg/L and at 20 km downstream it was in the range
of 1250-2721 mg/L. The permissible level of chlorides in Class-C water bodies is
600 mg/L. BOD level in the Noyyal river at 2km upstream of Tiruppur was in the
range of 1- 48 mg/L and at 5 km down stream of Tiruppur it was found to be in
the range of 7-36 mg/L, and at 20 km down stream the BOD was in the range of
1-24 mg/L as against the permissible level of 3 mg/L. COD in the upstream was
2- 324 mg/L and at 5km down stream was in the range of 56-243 mg/L and at 20
km downstream the COD was in the range of 17 - 292 mg/L.
39
The above study reveals that even before the river reaches Tiruppur it
is polluted. The reason is, while the river Noyyal crosses Coimbatore indusial
city (45 km upstream of Tiruppur) it carries large quantity (approx. 60 MLD) of
sewage along with electroplating and textile dyeing industrial effluents. When the
river crosses Tiruppur, it further carries the partially treated effluent discharged
by Tiruppur textile processing units and Tiruppur city sewage. This continues
upto Orathupalayam dam. Pollution concentration in the river is more in summer
than in winter. The existing moderate flow in Noyyal is not sufficient for diluting
the pollutants. Except for the rainy season when there is some dilution, the river
water is unfit for irrigation.
2.3.5 Orathupalayam Dam Water Quality
In the Orathupalayam dam, the TDS (Table 2.4) was measured in the
range of 4256-7888 mg/L, and chloride was measured in the range of 1629-
2718mg/L. BOD was in the range of 2-35 mg/L and COD was in the range of 40-
144 mg/L. The results are presented in Figure 2.15 to 2.18.
The Orathupalayam dam was constructed during 1992 across Noyyal
river for irrigating 19500 acres land in Karur district and 500 acres of land in
Erode district (Environmental Cell Division, PWD, 2008). But due to the semi
treated effluent from dyeing units and the untreated domestic sewage discharged
into the Noyyal river and stored in the dam, the entire river eco system below
Tiruppur and in and around Orathupalayam dam has been damaged. The surface
water, ground water, soil and land have been all degraded. The quality of water
for irrigation is determined by the effects of its constituents both on the crop and
the soil. The high TDS and chlorides in the river water will have impact on the
plant (i) direct osmotic effects of salts in preventing water uptake by plants, (ii)
40
direct chemical effects upon the metabolic reactions in the plants (toxic effect)
and (iii) any indirect effect through changes in soil structures permeability and
aeration.
In view of the polluted water flow in the river Noyyal no agriculture
activities take place in the down stream side of Tiruppur. Hence the very purpose
of Orathupalayam dam is defeated. The fishing activity in the dam was also
affected. Bio-assay test conducted revealed that the fishes are bleached. Many
dyes commonly used in Tiruppur are known to have serious health implications.
The textile dyeing units use soda ash, sodium chloride, soap, and fixing
agent in the process. This leads to release of soluble sodium in the effluent and
ultimately reaches the river. The percent soluble sodium in the Noyyal river water
was in the range of 38- 92%. In Noyyal river water, most of the times PSS was
above 60. When this water is applied for irrigation it leads to sodium hazard. In
normal soils, calcium and magnesium are the principle cations held by the soil in
replaceable or exchangeable form. Sodium tends to replace calcium and
magnesium when continuously applied through irrigation waters. An increase of
exchangeable sodium in the soil causes deflocculation of soil particles and
promotes compaction, thereby impairing soil porosity and the water and air
relations of plants.
41
Table 2.4 Quality of Noyyal River Water and Orathupalayam Dam Water
S.No.
Location Parameter Apr’08May’0
8Jun’08 Jly’08
Aug’08
Sep’08 Oct’8Nov’0
7Dec’08 Jan’09 Feb’09 Mar’09
1 Mangalam (2 KmUpstream of
Tiruppur)
TDS 900 5528 3616 4608 5336 3220 1980 4616 3088 4100 3628 4836
Chloride 233 2399 1899 1961 2019 1519 962 1481 865 1654 2547 981
Sulphate 24 273 405 157 538 203 159 426 279 355 494 271
BOD 1 1 2 36 1 48 12 8 4 4 1 1
COD 2 41 8 194 17 324 72 65 49 82 49 24
%
Sodium68 83 71 85 70 86 88 68 38 78 87 57
2 Kasipalayam
(5Km Down
stream ofTiruppur)
TDS 3788 3748 5276 4944 4164 5868 1716 3900 3604 4388 5476 4904
Chloride 1649 1749 2199 2327 1961 2442 808 1417 1481 1904 1981 2315
Sulphate 322 154 329 240 203 444 169 312 323 311 278 370
BOD 7 30 24 36 12 9 6 36 20 12 18 15
COD 57 113 56 243 116 73 56 243 146 246 243 138
%Sodium
85 86 88 87 84 69 88 83 75 85 91 81
42
Table 2.4 (continued)
3 Anaipalayam (20
Km Down stream
of Tiruppur)
TDS 2372 3840 4808 4312 4916 3956 6636 3552 3528 4160 5076 5080
Chloride 1349 1699 2649 1442 2346 1692 2721 1250 1586 1500 2028 2185
Sulphate 295 451 350 380 150 368 769 235 313 405 234 381
BOD 13 1 24 5 24 36 4 23 8 2 2 24
COD 94 17 64 41 208 292 40 162 81 33 243 146
%Sodium
85 81 89 50 87 89 67 83 77 54 90 86
4 OrathupalayamDam (32 km down
stream of
Tiruppur)
TDS 7888 6332 7184 7342 6795 6564 6127 6090 5671 5044 46244256
Chloride 2324 2124 2324 2456 2654 2718 2568 2350 1934 1629 18401950
Sulphate 379 312 364 379 394 323 304 316 286 317 417276
BOD 18 11 17 16 19 35 22 16 12 14 25
COD 88 128 136 120 134 112 130 124 118 144 4080
%
Sodium92 84 90 81 74 85 75 72 66 63 70
88
All Parameters are in mg/L except % Sodium. IS 2296 : 1982 Standards for Class C Water Body : TDS - 1500 mg/L, Chlorides - 600 mg/L, BOD - 3
mg/L). % sodium for irrigation 60 (max. limit)
43
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
Ap
r'0
8
Ma
y'0
8
Ju
n'0
8
Jly
'08
Au
g'0
8
Se
p'0
8
Oc
t'8
No
v'0
7
De
c'0
8
Ja
n'0
9
Fe
b'0
9
Ma
r'0
9
Month
TD
S m
g/L
Mangalam Kasipalayam Anaipalayam Orathupalayam Dam
Figure 2.15 TDS Level in Noyyal River and Orathupalayam Dam
0
500
1000
1500
2000
2500
3000
Ap
r'0
8
Ma
y'0
8
Ju
n'0
8
Jly
'08
Au
g'0
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p'0
8
Oc
t'8
No
v'0
7
De
c'0
8
Ja
n'0
9
Fe
b'0
9
Ma
r'0
9
Month
Ch
lori
de
s m
g/L
Mangalam Kasipalayam Anaipalayam Orathupalayam Dam
Figure 2.16 Chlorides Level in Noyyal River and Orathupalayam Dam
44
0
10
20
30
40
50
60
Ap
r'0
8
Ma
y'0
8
Ju
n'0
8
Jly
'08
Au
g'0
8
Se
p'0
8
Oc
t'8
No
v'0
7
De
c'0
8
Ja
n'0
9
Fe
b'0
9
Ma
r'0
9
Month
BO
D m
g/L
Mangalam Kasipalayam Anaipalayam Orathupalayam Dam
Figure 2.17 BOD Level in Noyyal River and Orathupalayam Dam
0
50
100
150
200
250
300
350
Ap
r'0
8
Ma
y'0
8
Ju
n'0
8
Jly
'08
Au
g'0
8
Se
p'0
8
Oc
t'8
No
v'0
7
De
c'0
8
Ja
n'0
9
Fe
b'0
9
Ma
r'0
9
Month
CO
D m
g/L
Mangalam Kasipalayam Anaipalayam Orathupalayam Dam
Figure 2.18 COD Level in Noyyal River and Orathupalayam Dam
45
2.3.6 Orathupalayam Dam Sediment Quality
The Orathupalayam dam is constructed across Noyyal river in 1992 by
the Public Works Department to store flood water for irrigating about 10000
acres. In course of time, the Noyyal river water stored in the dam was rendered
unfit for irrigation and fisheries owing to the high TDS and other pollutants
carried by the industrial effluent. However the dam water is released periodically
to take care of release of stored water and also to respond the inflow during rainy
season. The worst affected portion is the sediments in the reservoir bed. These
sediments absorb the pollutants in the water stored in the dam and also contribute
in a reverse way to pollute the water stored in case reservoir inflow is of good
quality. The area of the sediment deposits in the reservoir is about 50000m2. The
depth of sediment is about 1 m. This is to be dredged and remediated so as to
protect the dam and the groundwater.
In order to assess the sediment quality, three dam sediment samples
were collected from the depth of 10-15 cms of the dam bed. Samples of 1 kg of
sediment are collected in a clean plastic container and get analyzed in TNPCB
Advanced Environmental Laboratory at Chennai. The sediment samples were
ground to pass through a 2 mm sieve for chemical analysis. The physico chemical
analysis of the sediments was carried out as per standard methods of tri-acid
digestion using nitric acid, perchloric acid and hydrofluoric acid of APHA (2005).
and analyzed using Atomic Absorption Spectrometer.
The quality of Orathupalayam dam sediment (Table 2.5) reveals the
presence of heavy metals of chromium, copper, zinc, and lead. Total chromium is
in the range of 77-102 mg/kg which is more than the hazardous concentration
limit of 50 mg/kg. The sediments also contain chlorides, sulphates, phosphates
46
and total kjeldahal nitrogen. Presence of heavy metals in sediments is due to carry
over of heavy metals in dyeing effluent. When the dam water is released for
irrigation, there are chances of heavy metals to enter into the food chain through
crop cultivated using this water.
Table 2.5 Quality of Orathupalayam Dam sediment
S.No.
Parameter Sample-1 Sample-2 Sample-3
Hazardous
Concentrationlimit as per
HW(M,H,&TM) Rules
2008
1 pH (50%solution) 7.74 7.31 7.59
2 Chlorides 3950 3650 1480
3 Sulphate 4520 3510 3060
4 TOC 27% 31% 30%
5 Sodium 5400 3240 1820
6 Potassium 50 51 40
7 Phenolic
Compound<0.0005 <0.0005 <0.0005 5000
8 Total Chromium
(D.B)102 86 77 50
9 Calcium 480 220 120
10 Magnesium (W.B) 100 24 24
11 Copper (D.B) 91 70 57 5000
12 Zinc (D.B) 175 121 102 20000
13 Lead (D.B) 28 51 62 5000
14 Nickel (D.B) <0.006 <0.006 <0.006 5000
15 Cadmium (D.B) <0.0008 <0.0009 <0.0010 5000
16 Arsenic (W.B) <0.001 <0.001 <0.001 50
17 Phosphate (D.B) 1060 1080 16 20000
18 Total Kjeldahl
Nitrogen700 513 700
Note: All parameters are in mg/Kg except pH
47
2.4 STUDIES CARRIED OUT BY VARIOUS DEPARTMENTS
In year 2003, based on the direction of the High Court of Madras in the
writ petition filed by the Farmers Association, the Loss Ecology (Prevention and
Payment of Compensation) Authority, Government of India had carried on
assessment study on the loss to ecology and environment and arrived a
compensation package to the farmers of Noyyal river basin. Madras School of
Economics had conducted a study on loss of ecosystem in Noyyal river basin in
year 2006 and estimated through physical research studies of water and soil
quality and bio-mapping followed by economic valuation.
In year 2007, Tamil Nadu Agricultural University, Coimbatore had
carried out a study on the effect of Tiruppur textile dyeing industries effluents on
land and ground water and concluded that the Noyyal river water was affected
due to dyeing factory effluent and the farmers in Tiruppur depend on wells for
irrigation. The productivity of many crops was less. Affected villagers had sold
their livestock due various reasons like reduced milk yield, loss in weight, water
scarcity. The water samples collected from wells in the affected regions of
Tiruppur taluk before monsoon showed moderately high pH and EC values which
exceeding their critical limits indicating its unsuitability for drinking and
irrigation. Further, the results of heavy metal analysis showed the presence of
metals such as chromium, cadmium, nickel and lead. Unless remediation
measures are undertaken, the impact will continue for several years even after
treatment measures are in place. The existing effluent treatment plants are unable
to reduce the total dissolved solids and chloride levels, resulting in continuing
contamination of soil and water. The environmental impact is not only in
Tiruppur (local) but in downstream areas also.
