C

MECH SEMINAR ON GLOBALISATION REGIONAL PROGRESS l

NEW DELHI, 19 APRf L 1 9 9 5

. . PROSPECTS AND POTENTIAL OF WATER MANAGTEMENT I N SOUTH I N D I A

George C C u r r i e, Managi ng D i r e c t o r Degremont I n d i a Limi ted, New Del h i

INTRODUCTION

I t i s a g rea t p r i v i l e g e f o r me t o be g iven t h i s oppor tun i t y t o

t a l k t o you on t h e sub jec t o f water management i n I n d i a , t h e home

o f water t reatment . I t may no t be known t o you, bu t t h e f i r s t

known t r e a t i s e on t h e treatment o f f o u l water t o make i t safe f o r

human consumption i s found i n Sansk r i t medicinal t e x t s d a t i n g

back almost 4000 years - and t h e process descr ibed o f f i l t r a t i o n

and d i s i n f e c t i o n does no t d i f f e r t o o g r e a t l y from t h e bas i c

p r a c t i s e s o f today. I t was recognised then, even i n such e a r l y

days 04 mankind's development, t h a t water i S t h e key t o a l l human

a c t i v i t y . Obviously water i s a pr ime f a c t o r f o r sustenance o f

l i f e , bo th d i r e c t l y and through a g r i c u l t u r e t o meet t h e growing <=,* A- , food needs o f t h e i nc reas ing popu la t ion , bu t i t i s a l s o a f a c t o r

i n almost a1 1 i n d u s t r i a1 en te rp r i ses , and i t s ~ o n t i nued * - -

YI

a v a i l a b i l i t y i s t h e r e f o r e a mat ter o f deep concern. Although

water covers over 70% o f t h e e a r t h ' s sur face, o n l y 2.7% o f t h i s

va luab le resource i s f r e s h water, ou t o f which l e s s than 1% i S

usable as t h e r e s t i S e i t h e r f rozen i n g l a c i e r s o r i c e caps, o r

e l s e i s l o s t through streams and r i v e r s t o t h e sea. Thus i n

I n d i a , a l though t h e p o t e n t i a l water resource i s assessed a t

around 1,869 cub ic km. per year, t h e u t i l i s a b l e water i s o n l y

about 690 cubi c km. /year.

* C S

I For tunate ly , water i S n e i t h e r created nor consumed bu t i S ..l

I r I.

! * converted i n form: r a i n f a l l on t h e mountains becomes r u n o f f t o

streams, then r i v e r s , u n t i l i t reaches t h e sea, where evaporat ion

i n t o t h e a i r , which r i s e s over t h e mountains, g ives r a i n ;

s i m i l a r l y i n d u s t r y uses water ma in ly f o r coo l ing , which i s l o s t

as steam o r discharged t o r i v e r s due t o increase i n d isso lved

s a l t s , and a g r i c u l t u r e uses water f o r i r r i g a t i o n , where i t i s

drawn up by t h e p l a n t roo ts , and most ly l o s t t o t h e atmosphere

; through t r a n s p i r a t i o n from t h e leaves. Hence t h e n a t u r a l c y c l e -- ,l J . . a l lows &he u t i l i s a b l e water a v a i l a b l e t o us t o be rep len ished.

- W , --:L - - . n . - - I - ?, ".- = -- t

' b* J 1 *- T4 "

, l -

,. . I - . -

- .- . --. . - - I . . - - h - y ' - t. L - L ' I . - P - . - . . . ' -za . -, - - < - - - , . '. . - - -+-

, n -: ,. ... - - . . h - . . . $. = , - - . , " rb- , l*. '- . , , * z . y

L --,-v.-='. W. - & L a ' ~ - : + 5 . . L - p ..J - C . - A='

To s u s t a i n and improve t h e q u a l i t y o f l i f e however, i t remains

necessary t o i n v e s t i n systems t o t a p t h i s water, t r e a t i t t o

meet necessary standards, t r a n s p o r t i t , s t o r e i t , d i s t r i b u t e i t

t o t h e users, and then t o c o l l e c t , t r e a t and s a f e l y dispose o f

t h e r e s u l t i n g waste water t o a l l o w i t s reuse f u r t h e r down t h e

cyc le . A l l o f t h i s requ i res a s i g n i f i c a n t investment w i t h i n t h e

framework o f an e f f e c t i v e water management s t r a t e g y .

A comprehensive water management s t r a t e g y can be considered t o

comprise o f t h r e e b a s i c f a c t o r s :

i) water resource a v a i l a b i l i t y and a l l o c a t i o n

i i ) water use reduc t i on by process a1 t e r a t i o n o r r e c y c l i n g

iii) treatment o f wastewaters f o r reuse by o the r sec tors

Resource A1 l ocat i on

Decis ions a f f e c t i n g resource a1 l o c a t i on a t t h e h ighes t l e v e l a re

l a r g e l y p01 i t i c a l i n nature, p a r t i c u l a r l y i n I n d i a where water

i S an issue under s t a t e c o n t r o l . I t i S i n t e r n a t i o n a l l y recognised

t h a t p o l i t i c a l dec is ions , taken f o r a shor t- te rm gain, may n o t

be optimum i n terms o f long- term b e n e f i t s f o r a l l o c a t i o n

p r i o r i t i e s . The p r e f e r e n t i a1 a1 l o c a t i o n o f water t o a g r i c u l t u r e

f o r i r r i g a t i o n a t subs id ised p r i c e s leads t o concent ra t ion on

more p r o f i t a b l e crops, i r r e s p e c t i v e o f t h e i r water needs f o r

c u l t i v a t i o n o r t h e e f f e c t o f t h e i r growth on s o i l degradat ion,

and t o wastefu l forms o f i r r i g a t i o n ( i t becomes u n a t t r a c t i v e t o

@rake c a p i t a l investment i n d r i p i rri g a t i o n schemes, f o r example,

desp i te t h e f a c t t h a t these consume o n l y a f r a c t i o n o f t h e amount

used by normal water ing avo id long- term problems of

sa l i n i z a t i o n o f t h e so i l ) . The use o f s t a t e o r n a t i o n a l borders

as boundaries f o r water c o n t r o l g ives r i s e t o d isputes as users

, a t t h e lbwer reaches o f r i v e r s demand inc reas ing r e c o g n i t i o n o f

t h e i r r i g h t s and requirements o f t h e waters, bo th i n terms o f

q u a n t i t y and q u a l i t y , s ince each s t a t e i s l o o k i n g p r i m a r i l y a t

t h e b e n e f i t s t o i t s own res iden ts r a t h e r than a t t h e optimum use

o f t h e water resource as a whole. Th is s i t u a t i o n may be avoided

by p l a c i n g c o n t r o l o f t h e water resources under t h e a u t h o r i t y of

bas in manaqement bo,d,ies, such ss are used i n France and many

o ther Western na t ions , whose r o l e i s t o a l l o c a t e and c o n t r o l t h e

a b s t r a c t i o n o f raw water throughout t h e catchment area o f each

major r i v e r bas in together w i t h c o n t r o l o f t h e acceptable q u a l i t y

o f d ischarges o f used waters back t o t h e r i v e r . I t i s impor tant

t o no te t h a t c o n t r o l o f a b s t r a c t i o n a p p l i e s a l s o t o t h e

e x t r a c t i o n o f groundwater f rom borehol es o r tubewel l s , s i nce

u n c o n t r o l l e d pumping from a q u i f e r s may e a s i l y become "water

m i n i ng", i . e. permanent depf e t i on o f t h e groundwater resource

through a b s t r a c t i o n a t a h igher r a t e than replenishment. Th i s

p r a c t i s e may q u i c k l y l ead t o an i r r e v e r s i b l e d e t e r i o r a t i o n o f t h e

a q u i f e r s t r u c t u r e , o r t o s a l i n e i n t r u s i o n near t h e coast , as i S

a l ready observed a t Madras and i n Gu jara t .

RECYCLING

Water r e c y c l i n g i nvo l ves t h e reuse o f wastewaters f rom one stage

o f an i n d u s t r i a l process as a source o f raw water i n t h e p l a n t

i t s e l f , w i t h o r w i thou t p r i o r t reatment . A t i t s u l t i m a t e l e v e l ,

t h i s g ives r i s e t o t h e "zero discharge" t a r g e t envisaged by t h e

USA's Clean Water Act, and hence a g r e a t l y reduced consumption

o f t h e water resource by i n d u s t r y . Thi S i s i n c r e a s i n g l y impor tant

i n I n d i a as t h e o v e r a l l water demand i S expected t o increase from

552 cub ic km./year i n 1990 t o 1,050 cub ic km./year i n 2025, w i t h

t h e p r o p o r t i o n o f water used by i n d u s t r y i nc reas ing from 2.7% t o

11.5%. One need o n l y compare t h i s p r o j e c t e d demand t o fhe

avai l ab1 e supply noted e a r l i e r as be i ng o n l y 690 cub ic km. /year

t o see t h e s i z e o f t h e looming problem, and t o apprec ia te t h e

necess i ty f o r reduc t i on i n t h e i n d u s t r i a l water requirement.

Techniques and a p p l i c a t i o n s o f water r e c y c l i n g are h i g h l y

i n d u s t r y and p l a n t - s p e c i f i c , however t o g i v e a comparison o f a

South I n d i a n i n d u s t r i a1 u n i t w i t h i n d u s t r y b e s t - p r a c t i se i n t h e

USA, t h e 1995 ne t demand f o r c o o l i n g water make-up by t h e t h r e e

mai n u n i t s compris ing Madras1 S Manal i i n d u s t r i a1 area i S

est imated a t 66.5 Ml/d. The average concent ra t ion r a t i o i n t h e

cool i ng systems i S around 2.5, i . e. 40% o f t h e water (some 26

m i l l i o n l i t r e s per day) i s no t a c t u a l l y used i n c o o l i n g bu t i s

d i scharged as t h e concentrat i on o f d i ss01 ved sa l t s becomes

excessive and leads t o s c a l i n g o f t h e system pipework. However

w i thou t s u f f i c i e n t t reatment, t h i S d i scharged water i t s e l f i S

a l s o t o o p o l l u t e d f o r use by downstream cansumers, and i s l o s t

- ~ - > ~ = . - . ? - ~ ~ 7 ' 8 7 L- -= .: - . .- . - - m , 71: : -.

L?--- 8 I - . - , I - - I -

A

-2 - . from t h e water resource. I n t h e USA, advanced coo l i ng

c o n d i t i o n i n g systems, avo id ing t h e l i m i t a t i o n s o f mu1 t i chemica l 1 dosing, have a1 lowed t h e average concent ra t ion r a t i o t o r i s e

above 20, i .e. l e s s than 5% o f t h e water i s l o s t by discharge,

o r an improvement i n water use o f around 90%. S i m i l a r l y t h e

i n t r o d u c t i o n o f pr imary (equi pment- level ) , secondary (process-

l evel ), and t e r t i a r y (p1 an t- l evel ) water recyc l i ng techniques has

a1 lowed paper and p u l p m i 11s i n Europe, USA and Canada t o reduce

water consumption t o around 20 m3/tonne, w i t h t h e bes t p l a n t s now

ach iev ing "zero d i scharget', whi 1 s t t h e average I n d i a n m i l 1

u t i l i s e s 200 - 250 m3 o f water t o produce t h e same tonne o f

paper, and t h a t w i t h an e f f l u e n t unsu i tab le f o r reuse by o the r

consumers i n t h e water chain

REUSE OF WASTEWATER

Reuse invo lves t h e t reatment o f one user group 's discharged

e f f l u e n t as a raw water source f o r a subsequent user, and i s an

area o f growing i n t e r n a t i o n a l importance as water suppl i e s

worldwide come under i ncreasi ng pressure from competing

consumers. I t i s a l s o an area i n which I n d i a a l ready has some

e a r l y experience, desp i te t h e r e l a t i v e n o v e l t y o f t h e techniques,

having had a p l a n t r e c y c l i n g 5 Ml /d o f domestic sewage f o r use

as cool i ng water and process water by Union Carbide, Bombay s ince

t h e e a r l y sevent ies. More r e c e n t l y , bo th Madras F e r t i l i z e r s

ti m i t e d and Madras Ref i n e r i es L im i ted have recent1 y pu t up

advanced wastewater t reatment p l a n t s based on t e r t i a r y t reatment

fo l lowed by reverse osmosis (RO) technology t o p a r t l y meet t h e i r

water needs from reuse o f domestic sewage from Madras C i t y . A

f u r t h e r expansion o f reuse o f domestic sewage by i n d u s t r y i n

Madras i S planned w i t h a new f a c i li t y t o be const ructed, s t a r t i n g

i n 1997, under funding from t h e Japanese OECF, once again

probably us ing R 0 technology.

Advanced wastewater t reatment f o r reuse normal ly requ i res

t e r t i a r y t reatment o f t h e sewage t o reduce f u r t h e r t h e suspended

s o l i d s , e i t h e r through f i l t r a t i o n o r f l o t a t i o n , together w i t h

removal o f phosphorus and n i t rogen . Carbon absorp t ion may a l s o

be used t o remove speci f i c organi c p01 l utan ts . Such treatment may

alone be s u f f i c i e n t t o a l l o w t h e wastewater t o be used i n

IF-' i n d u s t r i a1 appl i c a t i ons, o r f o r i rri gat i an p u ~ p o ~ e s growibed

there are no pathinagens present, however where t he t r ea ted

sewage conta ins a h i gR level o f d i ssslved sa l t s , o r where i t i S

intended for eventual potab3e reuse fo l lowing groundwater

r e i n j e c t i o n such as a t Orange County, Cal i forn i a 's Water Factory

#21, deminsral i s a t i o n and d i s i n f e c t i o n i s a1 so required. A1 though

R0 has been used on the p7 ants a t Madras, other demineral i s a t i o n

techni ques such as evaporati on, e1 ec t rod i aTysi S o r i o n exchange

may by equal ly s u i t a b l e and may have lower c a p i t a l and running

costs. As w i t h recyc l ing , Phis i s an area where the exact

requi reaients of t he user(s1 must be p rec ise ly determined i n order t h a t t he most e f f i c i e n t process can be i d e n t i f i e d to meet the

q u a l i t y requirewent3 i n the most cos*-afFsctive manner.

CONCLUSION

Despite i t s fundamental and apparently simple nature, the t o p i c

o f water and i t s management t o the bene f i t o f a l l sectors o f the

community i s becoming an increas ing ly complex f i e l d , and t h i s

t rend i s se t t o cont inue w i t h the increasing populat ion and

urbanisat ion o f Ind ia . Overal l con t ro l o f the abstract ion, use

and discharge o f water must be seen t o be a p r i o r i t y , and the

best worldwide p rac t i ses o f i ndus t ry must be adopted as on ly

these w i l l secure the long-term a v a i l a b i l i t y o f the water

resource necessary f o r the f u t u r e development o f the country. A s

Ind ian indus t ry benchmarks i PS output qual i t y against i t s

i n te rna t i ona l competit ion, SQ i t must lea rn t o benchmark i t s

e f f i c i e n t use o f a1 1 inputs, i nc lud ing i t s resource o f water.