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I ISSN 0310 - 0367 I Official Journal of the

rA•~i i;M MM~ t/M i:4 ;E ~I •J Vol. 11, No. 3, September 1984-$2.50 Registered by Australia Post -

publication no. VBP 1394


FEDERAL PRESID ENT F. Bishop , Scott & Furphy, 390 St . Ki lda Ad .. Albert Park , 3004

FEDERAL SECRETARY F. J . Carter, Bo x A232 P.O. Sydney Sth ., 2001 .

FEDERAL TREASURER J . H. Greer. Cl - M .M.B.W. 625 Lt . Collin s St .. Melbourne , 3000.

water eJ Offi c ial Journal

AUSTRALIAN WATER AND WASTEWATER ASSOCIATION

Vol. 11, No. 3, September 1984

BRANCH SECRETAR IES Ca nberra, A.C.T. J . E. Dymke , 4 Story St ., Curtin , 2605. Office 062 (54 1222)

New South Wa les D. Ru ssel l. Camp Sco tt & Furphy , 781 Pa ci fic Highway, Chatswood 2067. (02 412 2688)

Vic tori a

CONTENTS Association News, Views and Comments .. ................ , ... . . .

6

J . Park,

S.A.W.S.C. Operator Training Centre , P.O. Box 409, Werribee, 3030. (74 1 5844)

Queens land D. Mac kay , P.O. Box 412. We st End 4101 . (07 44 3766)

IA WPRC News ........... ... . . . .. . .. .

10

Byproducts of Chlorination -8. C. Nicholson, K. P. Hayes and D. B. Bursi/I . ...... .

11

Calendar ... ... ........ .. ... . . ... .. ...... . . .. .. . ... . .

15

Land Management-Key to Water Quality Control -R. E. Hartley, D. J. Maschmedt and D. J. Chittleborough

18

Disinfection of Water for Control of Amoeba -B. S. Robinson and P. E. Christy .. .. .......... .. . .

21

Water Treatment for the Northern Towns of South Australia -R. C. Thomas ....... . ....... ........... . ..... . . . .. .. . . . .

29

Technical Interests . . ............... . . . .... ... .... . .... .. ... . .

32

Plant and Equipment .... ...... ........ . ... . ..... .. .

33

So uth Austra li a A . G latz. State Water Labo rat o ries , E. & W.S. Private Mail Bag , Sal is bury, 5108. (259 0319)

Western Austra li a A. Loo. 455 Beach Ad .. Carine. 6020. (09 447 6550)

Tasmania G. Nolan , G.P.O. Box 78A Hobart , 7001 . (002 28 0234)

Northern Territory G. Sleeman , P.O. Box 37283 Winne llie, N.T. 5789. (089 81 5772)

EDITORIAL & SUBSCR IPTION CORRESPONDENCE G. A. Goffin . 7 Mossman Dr .. Eagleman! 3084 03 459 4346

ADVERT ISING Mi ss An n Sykes. Appita, 191 Royal Parade. Parkvill e 3052 . 03 347 2377

COVER PICTURE A model of the Morgan Water Filtration Plant on the River Murray, now under construction, this 200 ML/d plant is the first of the Engineering and Water Supp ly Department 's programme for upgrading of water supply to the Northern Towns of South Australia. Designed by Camp Scott & Furphy PIL, construction is by contract supervised by the Department. The plant is lo cated at the si te of the existing pumping s tation supp lying ch lorinated and pH corrected water to the 'Iron Triangle ' town s of Whyalla , Port Augus ta and Port Pirie. The plant features include provision for control of TH M 's while maintaining adequate disinfection and a micro -process or based data aquisition and contro l system. The installation is designed for intermittent operation to permit use of the four large pumping stations on the Morgan -Whyalla pipeline during off-peak power periods. This necess itated some unusual design features including an automatica lly contro lled 's oft s tart-up' to maintain water qualit y. Front cover donated by Engineering & Water Supply Dept., S. Australia.

The statements made or opinions expressed in 'Water ' do not necessarily reflect th e views of the Australian Water and Wastewater Association , its Council or comm ittees .

WATER September, /984

I


BY PRODUCTS OF CHLORINATION B. C. Nicholson, K. P. Hayes and D. B. Bursill ABSTRACT The use of chlorination for disinfection of water supplies is a well established , effec tive process, but it has been under exte·nsive investigation in rece nt years. The formation of trihalomethanes during the chlorination of water, and th e concern for the possible adverse effects of these compounds on public hea lth has prompted a wide ran ge of s tudies relating to the toxicity of th e trihalomethanes, the formation and co ntrol of trihalomethanes and other byproducis, and a closer examination of alternative disinfectants. This paper summarises the work don e on the identification of byproducts of chlorination and presents so me of the results obtained in South A ustralian waters.

INTRODUCTION Di sinfecti on of drinkin g water using chlorine has been carried out for many years. It was introduced in the Un ited States in 1908 a nd its effect o n the redu cti o n of typho id feve r was soo n readil y a ppa rent (NAS, 1977) . Subsequent ly it was recognised that chlorination of waters conta in ing pollutants such as ph eno ls could produce undesirable reaction products with very low taste and odour threshold s e.g. ch lorinated phenols (Burttsc hell el al, 1959) . However it was a lmost 70 years before it was di scovered tha t chl orine reacted with natura ll y occurring organic mat ter in water (the humic a nd fulvic acids) to produ ce the triha lo m et h a n es (THMs) ch loroform (CHCl 3 ) , bromodichloromethane (CHC l , Br) , dibromochlorometh a ne (CHCIBr,) a nd bromoform (CHBr, ) (Rook, 1974; Bell ar e l al, 1974). With the fi ndi ng that CHCl 3 is carcin ogenic in rat s and mice and may therefore be ca rcinogeni c in m a n, co nsiderab le atten tion has now been focussed on the chemistry of the ch lori nation process . This appli es not on ly to th e reaction of chlor ine wi th na tura ll y occurring organics in water, but a lso to t he reaction of ch lorine used for disin fection of was tewa ter and the reactions of chlorine used for bl eac hing in th e pu lp a nd paper industry where effl uents may be toxic to fi sh , taint fi sh flesh or contam inate drinking water. There a re a number of co mpound classes whi ch have identified in water subj ected to chl ori nation and in laboratory st udi es associa ted with these processes, and th ese a re d iscussed below.

Dr. Bren/on N icholson and Mr. Keith Hayes are Scientific Officers in the Organic Chemis1ry Section of th e State Water Laboralory, Engineering and Waler Supply Depar1m en t, So uth A ustralia. Mr. Don Bursi/I is Senior Chem ist with the Organic Chemistry Section.

K. Hayes

B. Nicholson

D. Bursill

TABLE t: THM LEVELS IN CHLORINATED DRINKING WAT ERS Country

THM Level (µg / L) CHCl,Br CHCIBr, CHBr,

Reference

II 755 7.70 48. 1 105.6 17 187 3.4 ND

4. 1 228

ND 288

Trussell et al, 1980 Bursill, 1983 Bolzer, I979

3.8 38. 1 4.4 3.2 7. 6 ND

0.9 8.4 ND

England (south eastern) (Lancashi re) (Southampton) France (Rhon-Alps) Germany (Bremen) (27 cities) Indonesia

5.8 35 17.43

6.4 27 13.25

5.0 52 6.8

5.0 <I 3.0

Japan (lbakari) Net herlands Nicaragua Philippines (southern) (northern) Sweden

61 54.0 57 4.9 1. 8 9.5

24 20.0 10 2.3

311 13.6 823 165 430.0 25 80 459

I 16 53.4 71 12 60.0 57 28 35

CHCI, Australia (south eastern) (South Australia) Au stri a

Belgiu m Brazil Canada (Ottawa) China Egypt

USA (NORS) (East Texas) (I owa) (NY State) (Southern Cal iforn ia) (Texas) (V irginia)

ND 289' 0-·'

0-·' ND

-

d

6.3 ND

13 ND 2.3 3 2.47

ND < 0.01 '

_j

I.I

1.7

2.2

10.0 <I 0.7

50.0' < I" ND

-

Quaghebeur & De Wu lf, I980 Trussell et al, 1980 Otson et al, 198 1 Trussell et al, 1980 Trussell et al, 1980 Trussell et al, 1980 McConnell, 1976 Bretl & Calverly, I979 Chambon et al, 1983 Batjer et al, 1980 Sonneborn & Bohn, 1978 Trusse ll et al, 1980 Fujii, 1977 Rook, 1974 Trusse ll et al, Trussell et al, Trussell et al, Eklund et al,

13.3 ND 1.2 1. 5 0.6

2. 0· ND ND ND 0.0 16

100 173 .1 11.5 2 51.0 92 3I

92' 242.0-·'

Symons et al, 1975

ND• 38' 27• 17·

Veerfstra & Schnoor, 1980 Schreiber, I980 Carns & Stinso n, 1978 Smith et al, 1980 Hoehn et al, 1977

-

d

1980 1980 1980 980

!

Glaze & Rawley , 1979

ND-not detected: a- maximum of reported levels for a number of samp les; b-groundwater; c-surface water: d- ma ximum of reported leve ls for each THM. ot necessarily referring to same samp le; e-maxim um of means for several locations: f-mean value of plant with highes1 mean: g-typ ical va lues.

TRIHALOMETHANES Foll owing the reports in 1974 that chlorination of drinking waters produced THMs the US E nvironm enta l Protectio n Agency (US E PA) were quick to co ndu ct a survey of levels of volati le ha loge nated hydrocarbo ns, including TH Ms , in 80 wate r supplies. Thi s was the Nationa l Organics Reco nnai ssa nce Survey (NORS) (Symons et al, l 975). As a resu lt of this work, simi lar surveys were ca rried out in the UK but no such survey has yet been carried o ut in Australia. THM levels have now been reported from various regions o f the world and some of the data are summ a ri sed in Tab le 1. Levels a re genera ll y sim ilar to those found during the NORS, but occas io na l h igher levels have bee n reported . Iod ina ted THMs have a lso been reported from some waters but levels would appear to be low. It was reported that t he

level of dich loroidomethane in water is usually in the range from less than O. lµ g/ L to 10 µg / L but thi s compound was detected more frequent ly than C HBr 3 in drinking water samples examined (Thomas et al, 1980). THM leve ls in So uth Austra lian waters have been monitored ex tensively a nd are genera lly hi gh in relation to levels overseas, and to overseas ' sta ndards' (Bursill, 1983) . 'Standards' for THMs in drinking water adopted by overseas countries and oth er orga nisat ions are shown in Tab le 2. The word standard is used loosely in describing these values as th ey a re not in a ll cases legally enforceab le lim its. Factors affecting the formation of THM s in water have been well es ta bli shed a nd include pH , chlorin e dose, reac tion time, tem peratu re, brom ide level and level of precursors. Th e formation of THMs fro m precursors such as humic and ful vic acid s has WATER September, 1984

11


TABLE 2. 'STANDARDS' FOR THM s IN DRINKING WATER ADOPTED BY OVERSEAS COU TRIES AND ORGANISATIONS. Country or organisation

Standard (µg i t)

Canada Ge rmany

350 25 100 30 (C HCI, only)

USA World H ealt h Organisation

been well documented an d a ppea rs to be the ma in pathwa y for THM formation in wate r (Rook, I 976; Stevens el al, I 976; O liver & Lawrence, I 979), a lth o ug h a lgae a nd th eir b yprodu cts ca n a lso produce THM s o n c hlorin a tion (O li ver & S hindl er, I 980; Crane et al, 1980 ; Hoehn et al, 1980). Simple m et h yl ketones, the m ost commo n classes of compounds und e rgoing the haloform reaction to produce THM s, would not appear to be important precursors in waters as unde r the co nditions of water c h lorination their react ion rates a re too slow (Morris & Ba um , I 980). T he influ en ce of bromid e o n THM formati o n is one of the most interesting aspects of t he THM formation process. Severa l resea rc h ers h ave show n that increases in bromide levels lead to inc reases in brominated THM s at the expe nse of c hlorinated compound s (Arguello et al, I 979; Oliver, I 980 ; Lu ong et al, I 982) . T h is is due to rapid oxidation of bromide to hypobromous acid by c hlorine (or more correctly h ypoch lorous acid) wh ich the n reacts in co mpe titi o n with the c hlorin e. Brom ide not o n ly influences the proportion of brominated THMs but a lso the overall yield of THM s, hi gher levels of TH M s being formed a t hi ghe r bromide leve ls for a g iven c h lorine dose . Thi s presumabl y occurs beca use h ypobromous acid reacts more rapidly than c hl orine wit h the precursors (O li ve r, 19 80 ; Min ea r & Bird, 19 80). However so me work suggests that, given suffi cie n t re action t ime , yie ld s a re not sig nifi ca nt ly different (Oliver, 1980) . Since h ypoc hlorous and h ypobrom ous acids react in competition but at differe nt rates, the proportion of brominat ed THM s shou ld depe nd on th e ratio of these co mpounds or the ratio of c hl ori ne to bromide a ss um in g brom ide oxidation is rapid in co mpari son with THM formation. Thus CHBr, would be expected to be the predominant THM in wate rs of normal sa linit y (b y So uth Australian standards) if precursor levels a re low a nd c hl orine doses suffi cie nt for d isin fection are a lso low. Thi s would explain the THM d istribut ion a t Mt. Gamb ie r in Sout h Australia where for a typica l THM level of 33 µg/ L , C H Br, constitutes 28µg / L of thi s total. C hlorine is used for di sinfecti o n on ly at low level s due to the low di sso lved o rga nic carbo n co ncen tration s ( < I m g/L). H ypobromous acid predominates a t low chl or in e doses with a consequent format ion of CHBr,. Brom ide levels in the raw water of thi s supply , th e Blue Lake, a re simi lar to th ose of metropolitan reservoirs where dissolved organic ca rbon levels are substa ntiall y hi gher (up to 20 m g/ L) and c hlorine doses for disinfection are a lso much hi gher. Recently work a lso sugges ts that bromin a ted THMs ma y be favoured b y hi g h pH , (Minear & Bird , I 980) a cond iti o n wh ic h app li es in Mt. Gambier 12

WATER September, 1984

water. Thi s too wo ul d partly explai n the distribution. Trih a lometha ne precursor levels are gene ra lly very hig h in So u th A ustrali a n waters. Thi s is evidenced from m easurement of th e trihalo m etha n e fo rm at io n pote n tia l whic h is t he sum of the THM leve ls measured when a high dose of c hlorine (40 m g/ L) is add ed to a water sa mple a nd the reaction a ll owed to proceed to comp leti on suc h t h at the qu a ntity of ch lor ine is no t limitin g (i.e. a c hl or ine residual still re main s after trihalometh a ne fo rm at io n is co mple te) . Th e time taken to obtain this measure ment ca n be reduced b y ca rr yin g out th e reaction a t a n ele vated te mpera ture (e. g . 40 ° C). The trih a lometh a ne formation potential of som e Sou th Austra lia n wa ters is shown in Table 3. These result s indicate that th e tri ha lo me thane co ncentra ti ons act ua ll y produced in the distribution systems a re lower than th e poten t ia l for their fo rmaton . Thi s is due to t he influ e nce o f di stribution syste m detention times, water temperatures a nd c hlorin e dose rates.

TABLE 3. TYPICAL TRIHALOMETHANE FORMATION POT E TIAL OF SOM E SOUTH AUSTRALIAN WATERS Location Warren Reservoir

Barossa Reservoir Happy Valley Reservoir Hind marsh Valley Res. Hope Valley Rese rvoir Litt le Para Rese rvoir Mannum-Rive r Murray Myponga Reservoir Morga n-Ri ve r Murra y Tai lem Bend-River Murray Blue Lak e

THMFP (µg / L) I I I 2 I

940 060 050 570 060 940 I 270 1,560 I 190 I 240 75

HALOGENATED KETONES I , I , 1-trichl oroaceto ne (TCA), a known precursor of C H CI, in the haloform reaction, was id e ntified in c h lor in a ted drinki ng water by Suffet et al, (I 976). Thi s co mpo und was id e ntifi ed short ly a ft erwa rd s in So u th A ustralian waters as a product of c hl ori nation, usin g gas chrom atogra ph y/ mass spectrom etry a nd has sin ce been found to be a ma jor vo lat il e p rod uct of c hlorinat ion. TCA has now been ide ntifi ed in a number of chl ori na ted drinking waters overseas (Guro l et al, 1983). Levels of 20 µg / L TCA are freq ue ntl y fo und in So uth Au strali a n waters with leve ls ge nerally being hi g he r in waters w ith a low pH. This re fl ects th e low sta bilit y of TCA unde r alkaline conditi o ns when it is rapid ly h ydrol ysed to C HCI, . It is int eres tin g that t he h ydrol ysis of TCA to C HCI, is more rap id in the presence of c hl ori ne in compari son with so lut ions wit hout chlorin e. This sugges ts that in chlorin a ted waters, prod uctio n of C HCI, from T CA occurs b y m ore than o ne mechanism (Gurol e1 al, I 983). Rook {1977) ide ntifi ed a number of more highl y c h lo rinated acetones in heav il y c hlorin ated wate r and peat ext racts, a nd these co mpound s have a lso bee n found in c hl o rin ated wastewa ter (Glaze & H e nderson, 1975). C h lor in a ted ketones are produced o n

c hl orin at io n of reso rci n o l, a m odel compo und for h umi c a nd ful-.ic acid s (Boyce & H ornig, 1983). Although no t yet positi ve ly id e ntifi ed in So uth Au s tr a lia n waters, chroma1ograp hic ev ide nce indicates that some dich loroacetone m ay be present but at low leve ls . These comp ou nds may be impo rtant in relation to hum a n hea lth as 1,3 -dichloroacetone has bee n shown to be a strong mut age n (Kringstad el al, l 983).

DIHALOACETONITRILES Members of this group of compound s were reported to be for m ed on c hlorination of wat er b y T re h y a nd Bi ebe r ( 1980) with a maximum co ncentrati on of 42 µg / L being reported. Oliver ( 1983) found that th ese c0m pounds were produ ced on c hl or inat ion of fulvic acid a nd a lgae whi c h a re the most lik ely THM prec ursors in natura l waters . Mo lar concentrat io ns we re fo und to be approximatel y IO per ce nt of molar THM conce n trations. The ha logen di stribution appears to fo ll ow th a t of th e THM s, i.e . di chloroacetonitrile is fo rm ed under conditions which favour formation of C HCI , , w hi le und er co ndi tio ns whi ch favour formation of C HBr,, th e formation of bro mina ted dihaloacetonitri les is faci lita ted . Altho ugh no quantitative data h ave yet been o bta ined for South Austra lia n wa ters, c h romatograp hi c ev ide nce indi cates th e presence o f di chloroacetonitril e with pe rh a ps bromochl oroace tonitrile in som e waters .

CARBON TETRACHLORIDE Thi s compound was monit o red during the NO RS carried o ut by the US E PA in 1975 a nd was fo und in a number of sa mpl es with the highest leve l being 3 µg / L (Symons et al, 1975). Ca rbon tetrach loride is frequent ly d etected during THM ana lys is of South Au stralian wa ters but co ncentrations a re a lways low a nd rarel y g reater thpn I l'g/ L. Ca rbo n tetrac hl o rid e in c hlorinat ed wate rs would ap pear to a ri se fro m th e c h lor in e itself w here it is present as a contamin ant (Cairo el al, I 979). Carbon tet rachloride, li ke C HCI,, is impo rtant in relation to hum a n hea lth as it is a lso a poss ibl e human ca rcin ogen .

HALOACIDS H a loac ids such as di- and trichloroacetic acid s a re on ly just bein g recogni sed as perhaps the m ajo r byproducts of wa te r c hl o rinati o n. These co mpo und s are n o t d etec ted b y m ethods suit ab le for THM a nal ysis a nd require m o re specific met hods for isolation and id e nt ificat ion . A s suc h these co mpo unds appear to h ave a lm ost been overlooked as importa nt byprod ucts of water c hl orin a ti on un1il recentl y. Th e hea lth effects of ingest ion of low levels of 1hese co mpo und s is not known, a lthoug h it is well known 1ha1 the pure compou nds ca n ca use severe burn s due to 1h eir hig h ly ac id ic nat ure. Rook ( 1977) initi a ll y id e ntifi ed dichloroacetic acid (DCAA) in heavil y c h lorin a ted water. S in ce that tim e D CAA a nd tric h lo roacet ic ac id (TCAA) have been ide ntified as t he m ajor reaction product s in the c hl or in a ti on of humi c a nd fu lvic ac ids (Miller

_l


er al, 1982: Mill e r & Ude n , 1983; C hristman er al, I 9 83 ), and mod el compound s (Boyce & H o rnig, I 983; Norwood er al, 1983). Levels of DCAA a nd T CAA in chlorinated tap wate rs wou ld ap pear to be similar to T HM leve ls (Uden & Miller , 1983). Th e relationship be tween a nd ha loacid and THM production ha been in vestiga ted in ex pe rim e nt s with ful vic acid. T CAA leve ls were found to be more than double those of C HCI, (Mi lle r er al, 1982) w hi ch ag rees reasonabl y we ll with the few data obtained on drinkin g waters. Analyses of c hl o rina ted South Au stra li an wat e rs, a lt houg h a t this tim e limited, confi rm that DCAA and TCAA a re present. Levels up to 200 l'g/ L T CAA have bee n d etermined and DCAA levels appear to reach this va lue in wate rs c hl orinated at norm a l rates . Dibromoacet ic acid has a lso been iden tified in one rela ti ve ly sa line water w hic h produ ces hi gh levels (up to 500 l'g/ L) o f C H Br,. In ves tigatio n of the product s of humic and ful vic acid chl orinat io n has s hown that D CAA a nd TCAA are th e major ha loaci d s formed , _however a number of hi g her ha loacid s are also for med (Chri stman er al, 1983) and these also need to be id entified and qu a ntifi ed .

OTHER CHLORINATED COMPOUNDS Ev idence su ggests that a large number of co mpound s of vari ou s ot her c hemi cal classes may o cc ur in c hlorin a ted waters but at very low leve ls. R ook (1977) id e ntifi ed a number of compo und s including c hl ora l and other h a logen a ted h ydrocarbons form ed o n c hlo rination of peat extacts . On heav y chl orina tion of reser vo ir water a numb e r of com pounds including h a logenated a lco ho ls a nd aro matic compo unds were id e ntifi ed . C hloral was a lso ide ntified by C hristman er al ( 1983) a nd b y Miller & Ude n ( 1983) from c hlorina tion of humi c a nd ful vic acids . C hlora l leve ls in tap wa ter were reported to be approx imately one te nth of C HCI , level s (Uden & Miller , I 983) . C hl o rin atio n of wastewaters was reported to produce a large number of co m pounds (G laze & H ende rso n , 1975). In th e case of wastewaters w he re man y co mpound s capable of being c hl o rinated, bes ides humi c and fu lvic ac ids, ma y be present, the range of chl o rin a ted product s could be ve ry large in d eed. The prese nce of other ha lo ge na ted com pounds, a part fro m THM s a nd ha loacids in So u th Au strali a n dr inkin g water is ev ident from the c hro ma tog rams in Figure I whic h have been obtained durin g routine THM a nal yses . The compound s respo nsible for peaks m arked w ith as terisks have not been id e ntifi ed . Th ey m ay be iodinat ed THM s, ha logenated ketones or aceto nitril es as prev iou sly discussed, or th ey ma y be ot he r compo unds . C losed Loop Strippin g Ana lysis (CLSA) has been used in the State W a te r La borator y to iso late a la rge num ber of vo la til e produc ts from c hl o rin a ted reserv ior water. A wid e va riet y of po lychl orinated h ydroca rbon s (saturated and unsa turat ed) has bee n fo und , th e deg ree of chl ori nati on ex te nding to substitution b y up to fiv e c hlorin e atom s for so me co mpo unds . Thi s would partl y account for th e hi g h c hlorin e d e mand of ce rtain

~

Ii . .,

0

NM

(2 )

7,,oi

l'

~

~

(6 )

4 )~

B)

A)

~

-

(I)

(7}

(2)

~

(5)

---I

. <5 l

~

r

(21g1

.

:::

( 2~ (! ~ )M

<':' ~'? '!

J_ ~

.

n~

(6)

ri

M

(5) (10)

M

~

~

(6)

~

(8 )

l

C)

I

~

D) (7)

(1)

~

~

I

~9)

1

I

I

(10)

I

M

. ,r--1-,-, ~

~r

Figure 1. Some chromatograms obtained during routine THM ana lyses stora ge of extracls In freezer; (3)-CHC IJ; (4)-carbon letrachloride: (5) - CH CllBr: (6)-C HCIBrJ; (7) - impurit y from interna l standard (tetrachloroelh yle ne): (8) - 1, t , l · lrichloroac eton e: (9)-CHBrl: (10)- internal stand ard (tetrachloroethan e). (I and 2) - conlamination through

Peaks mark ed • hav e nol bee n id en lified .

Sample A (Solvent) B C D

Concentration (µg/ L) C HCI,

CCI,

C H C l, Br

C HCIBr,

TCA

C HBr,

< 1 42 372 70

< 0.05 0. 50 0.80 < 0 .05

< 1 17 116 83

< 1 4 28 47

< 1 < I 4 IO

< 1 < 1 1 6

waters co nta ining hi gh levels of naturally oc-. curring o rgani cs. The compou nds formed in this type o f react ion play no useful part in the di sinfection process.

CHLORINATED PHENOLS It is well known that ph e nols are very im portant in re lat ion to water qualit y as c hlorinated pheno ls with very low taste and odour thres holds ma y be produced on c hlorination. Although ex pe riment s with m odel compounds for humi c a nd fulvic acids have shown that ch lo rin ated phenols may be p rod uced on c hlorination (Larson & Rockwell, 1979; Norwood et al, 1980; Boyce & H orn ig, 1983) , no ch lo rinated aromat ic compo unds were found o n chlorination of humic acid (C hri stm a n er al, 1983) and there is li tt le evi d e nce t hat c hlorin a ted phenol s occur in ch lorinated drinkin g wate rs. However a rec urring taste a nd odour proble m with the ch lori nated water supply at Mt. Gamb ier wou ld appear to be due to bromina ted p heno ls . Tribromoph e no l has been identified b y gas chromatography/ mass spectrometry and b y th e re tention tim e of it s pentafluorobenzyl d e ri vative. It s concentrat ion in the latest incid e nt was found to be 5 l'g/ L. Th e occurrence of brominated phe no ls is not surpri sing as th e co ndition s under which the wa ter is chl or in ated leads to C HBr, as th e predomi -

nant THM so hypobromous acid is obv iously th e halogenatin g agent. However the precurso r and its source art unknown at thi s time but Masumoto (1982) has identifi ed phenol s in water which wou ld appear to ari se from plant material a nd these sa me phenols produce c hlorin ated phenols on c hlorinati on (Larson & Rockwell, I 979). Of particu lar interest in relation to the ch lorin ation process a re th e effluent s from pu lp and paper industries where c hlo rination is carried out for bleaching purposes. Compounds of a number of different classes have been identified. Nonpolar compound s such as C HCI, and chl orinated cyme nes, and chlorin ated pheno ls, including catechols and guaiacols have been identified (Bjorset h er al, 1979; Paas irvirta el al, 1983) . T hus effl uent s from pulp and pape r indu stri es a re poten tial ly ser iou s sources of pollu tion from ch lor inated compounds.

TOTAL ORGANIC HALOGEN (TOX) The identification of a ll b yproduct s of c hlorination would requ ire len gth y and complex analytical procedures. A more genera l parameter which is a measure of the amount of ha logen incorporated into orga ni c mo lecules is the Total Orga ni c H alogen (TOX). In the analys is of water for TOX the organ ics in WATER September, /984

13


the water samp le are extracted by some means , usually adsorption on carbon. The halogens present are converted to halide by pyrolysis, and the halide measured. Although giving no indication as to the identity of compounds present, it is a relatively rapid procedure for estimating the degree of contamination by halogenated compounds formed during the ch lorination process . That THMs are on ly part of a spectrum of halogenated organics formed during chlorin ation is evident from TOX measurements. Oliver ( 1978) showed that 43 per cent of the organic ch lorine produced on chlorination of fulvic acid was in the form of nonvo lati le ch lorinated organics. However at pH 11 essentia lly all the TOX was accounted for by THMs wh ile at pH 5 the major part of the TOX was nonvolatile compounds. These results are consistent with THMs being readi ly formed from in termediates at high pH whi le at low pH intermediates are more stable with a decrease in THM production. A recent report states that the level of TOX compounds may be 3 to 5 times higher than the level of total volati le halogenated hydrocarbons (Saleh & Mokti , 1983). TOX measurements have great promise as routine parameters in water quality assessment. The relationship of TOX to THM leve ls suggests there may sti ll be more halogenated compounds to be identified in ch lorinated waters .

CONCLUSIONS There are a wide range of compounds formed during the ch lori nation of water containing naturally occuring hum ic and fulvic material. Most of these byproducts are formed at very low concentrations, but some compounds, namely the haloacids and haloketones can occur at levels wh ich approach those of the trihalomethanes. Because there is concern that some of the byproducts of chlorination including the trihalomethanes may have so me adverse health effects, and since none of the alternatives to chlorination are completely wit hout problems there will continue to be a great emphasis placed on studying the reaction s of chlorine with humic a nd fulvic material. This is particularly true for the non-volatile compounds whi ch are not readily identifiable, but may comprise the major proportion of the byproducts formed .

REFERENCES ARGUELLO, M . D., CHR ISWELL , C. D. , FR ITZ, J. S., KISSINGER , L. D. , LEE, K. W . , RICHARD, J. J. a nd SVEC, H . J. (1979). Trihalomethanes in water: a report on occurrence, seasonal variation in concentrations, and precursors of tri halomethanes. J. Am. Water Works Assoc., 71 , 504-508. BATJER , K., GABEL, 8 . , KOSCHORREK, M., LAHL, U., LIERSE, K. W., STACHEL, 8. and THIEMANN, W. (1980) . Drinking water in Bremen: Trihalomethanes and social costs. Sci. Total Environ., 14, 287-29 1. BELLAR, T. A., LICHTENBERG, J. J. and KRONER, R. C. (1974) . The occurrence of organohalides in chlorinated drinking waters, J. Am . Water Works Assoc., 66, 703-706 . BJORSETH , A., CARLBERG, G. E. and MOLLER, M . (1979). Determination of halogena ted compounds and mutage nicit y testing of spent bleach liquors. Sci. Total Environ. , 11, 197-21 1. 14

WATER September, 1984

BOLZER, W. (1979). Zur Frage der Bedeutu ng von Trichlormethan fur das Weiner ¡Trinkwasser. Gas/ Wasser/ Warme, 33, 80-82 . BOYCE , S. D. and HORNIG, J. F. (1983). ' Reaction pathways of trihalometha ne formation from the halogenat ion of dihydroxyaromatic model compounds. Environ. Sci. Technol., 17, 202-211. BRETT, R. W. and CALVERLY, R. A. (1979). A one-year survey of trihalomethane concentration changes within a distribution system. J. Am. Water Works Assoc. , 71, 515-520 . BURSILL , D. 8. (1983). Trihalomethanes in South Australian water supplies. Proc. AWWA 10th Federal Convention, Sydney, April 1983, 4-1 4-13. BURTTSCHELL , R. H., ROSEN , A. A. , MIDDLETON , F. M. and ETTINGER , M. 8. (I 959). Ch lorine derivatives of phenol causing taste and odour. J. Am. Water Works A ssoc., 51, 205-214 . CA IRO , P. R., LEE, R. G., APLOW ICZ, 8. S. and BLANKENSHIP , W. M. (1979). ls your chlorine safe to drink? J. Am. Water Works Assoc., 71, 450-454. CARNS, K. E. and STINSON, K. 8. (1978). Controlling organics: T he East Bay Municipal Untility District experience. J. Am. Water Works Assoc., 70, 637-644. CHAMBON, P., TAVEAU, M., MOR IN, M ., CHAMBON, R. and VIAL, J. ( 1983). Survey of trihalomethan e levels in Rhone-Alps water supplies. Water Res., 17, 65-69. CHR ISTMAN, R. F., NORWOOD, D. L., MILLINGTON , D. S., JOHNSON , J. D . and STEVENS, A. A. ( 1983). Identity and yields of major halogenated products of aquatic fulvic acid chlorination. Environ. Sci. Technol. , 17, 625-628 . CRANE, A . M., KOVACIC , P. and KOVACIC, E. D. (1980). Volatile halocarbon production from the chlorination of marine algal byproducts , including O-mannitol. Environ. Sci. Technol., 14, 137 1- 1374. EKLUND, G., JOSEPHSSON, 8. and ROOS , C. (1978). Determination of volatile halogenated hydrocarbons in tap water, sea water and industrial effluents by glass capi llary gas chromatography and electron capture detectio n . J. High Res. Chromatog. and Chromatog. Commun., I , 34-40. FUJII, T. (1977). The determinat ion of traces of o rganohalogen compounds in aq ueous solution by direct inj ection gas chromatography-mass spectrometry and single ion detection. Anal. Chim. Acta, 92, 11 7- 122. GLAZE, W . H . and RAWLEY, R. (1979). A preliminary survey of trihalomethane levels in selected East Texas water . upplies. J. Am. Water Works Assoc., 71, 509-515. GLAZE, W. H . and HENDERSON, J. E. (1975). Formation of organochlorine compounds from the chlorination of a municipal secondary effluent. J. Water Pollut. Control Fed., 47 25 11 -2515 . GUROL, M. 0 ., WOWK , A ., MYERS, S. and SUFFET, l. H. ( 1983). 'Kinetics and mechanism of haloform formation: chloroform formation from trichloroacetone, in Jolley, R. L., Brungs, W. A., Cotruvo, J . A., Cuming, R. 8 ., Mattice, J. S. and Jacobs, V. A., Eds. 'Water Chlorination: Environmental Impact and Health Effects', Vol. 4, Book I, Ann Arbor Science Publishers, Ann Arbor, Michigan, 269-284 . HOEHN , R. C. , BARNES, D. 8., THOMPSON, 8. C., RANDALL, C . W. , GR IZZARD, J. and SHAFFER, P. T. 8 . (1980). Algae as sources of tri halomethane precursors. J. Am. Water Works Assoc., 72, 344-350. HOEHN , R. C., RANDALL, C. W., BELL, F. A. and SHAFFER, P . T. 8. (1977) . Trihalomethanes and viru ses in a water suppl y. J. Environ. Eng. Divis., Proc. Am. Soc. Civil Engs., 103 (EE5), 803-814.

KRING:'iTAD, K. P., LJUNQUIST,. P. 0 ., DE SOUSA, P . and STROMllERG, L. M. (1983). On the formation of mutagens in the chlorination of humic acid. Environ . Sci. Technol. , 17, 553-555. LARSON, R. A. a nd ROCKWELL, A . L. (1979). Chloroform a nd chloropheno l production by decarboxylation of natural acids during aqueous ch lorination. Environ. Sci. Technol. , 13 , 325-329. LUONG, T. V., PETERS, C. J. and PERRY, R. (1982). Influence of bromide and ammonia upon the formation of trihalomethanes under water treatment conditions . Environ. Sci. Technol., 16, 473-479. MATSUMOTO, G. (1982). Comparative st ud y on organic constituent s in po ll uted and unpolluted inland aquatic environments-lll. Phenols and aromatic acids in polluted an unpollu ted waters. Water Res. 16 , 55 1-557. McCONNELL, G. (1976). Halo organics in water suppli es. J. Inst. Water Eng. Scient., 30, 431-435. M ILLER,. J. W . and UDEN, P. C. (1983). Characterization of non volatile aq ueous chlorination prod ucts of humic substances. Environ. Sci. Technol., 17, 150-157. MILLER, J. W., UDEN, P . C., and BARNES, R. M. (1982). Determin atio n of tric h loroacetic acid at the parts-per-billion level in water by precolumn trap enrichment gas chromatography with microware plasma emission detect ion . Anal. Chem., 54 485-488. M INEAR, R. A. and BIRD , J. C. (1980). Trihalomethanes: impact of bromide ion concentrat ion on yield, species distribution , rate of formation and influence of other variables, in Jolley, R . L., Brungs, W. A. and Cumm in g, R. 8., Eds., ' Water Chlorination : Environmental Impact and Health Effect s' . Vol. 3, Ann Arbor Science Publishers, Ann Arbor , Mich igan, 151 - 160. MORRIS, J. C. and BAUM, 8 . (1980). 'Precursors a nd mechanisms of haloform formation in the chlorination of water suppli es, in Jolley, R. L., Gorchev, H . and Hamilton , D. H. , Eds., 'Water Chlorination: Environmental Impact and Health Effects', Vol '. 2, Ann Arbor Science Publishers, Ann Arbor, Michigan, 29-48. NAS (1977), 'Drinking Water a nd Health ' National Academy of Sciences, Washington. NORWOOD, D. L., JOHNSON, J. D., CHRISTMA~ R. F. , HASS, J . R . and BOBENR IETH, M. J . ( 1980). Reactions of chlorine with selected aromatic models of aquatic humic material. Environ. Sci. Technol., 14, I 87- 190. OLIVER, 8. G. ( 1978). Chlorinated non-volatile organics produced by the reaction of chlorine with humic materials . Canad. Res., 11(6), 2 1-22. OLIVER, 8. G. (1980). Effect of temperature , pH and bromide concentration on the tri halomet hane reaction of chlorine with aquatic humic material, in Jolle y, R . L. , Brungs, W. A. and Cumming, R. 8., Eds. , 'Water Ch lorination, Environmental Impact and Health Effects', Vol. 3, Ann Arbor Science Publishers, An n A rbor, Michigan, 14 1- 149. OLIVER, 8. G. (1983). Dihaloacetonitriles in drinking water: algae and fulvic acids as precursors . Environ. Sci. Technol. , 17, 80-83. OLIVER, 8. G. a nd LAWRENCE, J. (1979). Haloforms in drinking water: a study of precursors and precursor removal. J. Am. Water Works Assoc. , 71 , 161 - 163. OLIVER, 8. G. a nd SH INDLER, D. 8. (1980). Trihalomet hanes from the chlo rination of aquatic algae. Environ. Sci. Technol. 14 , 1502- 1505 . OTSON, R., WILLIAMS, D. T. , BOTHWELL, P. D. and QUON, T. K. ( 198 1). Comparison of trihalomethane levels and other water quality parameters for three treatment plants on the Ottawa River. Environ. Sci. Technol., 15, 1075-1080.

l

l


PAASIV IRTA, J., KNUUTINEN, J., TARHANEN, J., KUOKANEN , T. , SURMAAHO, K., PAUKKU, R. , KAARIAINEN, H ., LAHTIPERA , M. and VEIJANEN, A. (1983) . Potential off-flavour compounds from chlorobleaching of pulp and chlorodisinfection of water. Waler Sci. Technol. , 15, 97-104. QUAGHEBEUR, D. and DE WULF, E . (1980) . Volatile halogenated hydrocarbons in Belgian drinking waters. Sci. Tola/ Environ., 14, 43-52. ROOK, J . J. (1974). Formation ofhaloforms during chlorination of natural wate rs. Waler Treal . Exam., 23, 234-243. ROOK, J. J . (1976). Haloforms in drinking water. J. Am. Waler Works Assoc., .68, 168-172. ROOK, J. J. (1977). Chlorination reactions of fulvic acids in natural waters . Environ. Sci. Technol., 11 , 478-482. SALEH, F. Y. and MOKTI, M. (1983). Fulvic acid and ch lorinated fu lvic acid in water sed iment : HPLC fractionation and spectroscopic characterizat ion , in Jolley, R. L., Brungs, W. A., Cotru vo, J. A., Cumming, R. B., Mattice, J. S. and Jacobs, V. A., Eds., 'Water Chlorination Environmental Impact and Health Effects', Vol. 4, Book I, Ann Arbor Science Publishers, Ann Arbor, Michigan, 201-217. SCHREIBER, J. S. ( 198 1) . The occurrence of ¡ trihalomethanes in pub lic water supply systems of New York State. J. Am . Waler Works Assoc., 73, 154- 159.

SMITH, V. L., CECH, I., BROWN, J. H. and BOGDAN, G. F. ( 1980). Temporal variations in trihalomethane content of drinking water. Environ. Sci. Technol., 14, 190- 196. SONNEBORN, M. and .B OHN , B. (1978) . Formation and occurrence of haloforms in drinking water in th e Federal Republic of Germany, in Jolley, R. L., Gorchev, H. and Hamilton , D. H., Eds., 'Water Chlorination: Environmental Impact and Health Effects' , Vol. 2, Ann Arbor Science Pub lishers, Ann Arbor, Michigan, 537-542. STEVENS, A. A., SLOCUM, C. J ., SEEGER, D. R. and ROBECK, G . G. (1976). Chlorination of organics in drinking water. J. Am. Waler Works Assoc., 68 , 615-620. SUFFET, I. H. , BRENNER, L. and SILVER, B. (1976). Identification of I , I, 1-trichloroacetone (I, I, 1-trichloropropanone) in two drinking waters: a known precursor in halofor m reaction. Environ. Sci. Technol., 10, 1273- 1275 . SYMONS, J. M., BELLAR , T. A., CARSWELL, J. K., DEMARCO, J. , KROPP, K. L., ROBECK, G. G., SEEGER, D.R., SLOCUM, C. J., SMITH, B. L. and STEVENS, A. A. (1975). ational Organics Reconnaissance Survey for halogenated organics. J. Am. Waler Works Assoc., 67, 634-648.

THOMAS, R. F., WE ISNER, M. J . and BRASS, H. J . ( 1980). The fift~ trihalomethane : dichloroiodomethane, its stabilit y and occurrences in chlorinated drinking water, in Jolley, R. L., Brungs, W. A. and Cumming, R. B., Eds., 'Water Chlorination; Environmental Impact and Health Effects', Vol. 3, Ann Arbor Scienc¡e Publishers, Ann Arbor, Michigan, 161-168. TREHY, M. L. and BIEBER , T. I. (1980) . Detection, identification and quantitative analysis of dihaloacetonitriles in chl o rinated natural waters, in Keith, L. H. , Ed ., 'Advances in the Identification and Analysis of Organic Pollutants in Water' , Vol. 2, Ann Arbor Science Publishers, Ann Arbor, Michigan, 941-975. TRUSSELL, A . R ., CROMER, J. L. , UMPHRES, M. D. I(ELLEY , P. E. and MONCUR , J. G. (1980) . Monitoring of volatile halogenated organics: a survey of twelv.c drinking waters from various parts of the world, in Jolley, R. L., Brungs, W. A., Cumming, R. B., Eds., 'Water C hlorination: Enviro nm ental Impact and Health Effects', Vol. 3, Ann Arbor Science Publishers, Ann Arbor, Michigan, 39-53. UDEN , P. C. and MILLER, J. W. (1983). Ch lorinated acids and ch lora l in dri nking water. J. Am. Waler Works Assoc., 75, 524-527 . VEENSTRA, J. N . and Schnoor, J. L. (1980). Seasonal variations in trihalomethane levels in I Iowa River water supply. J. Am. Waler Works Assoc., 72, 583-590.

*

CALENDAR 1984/85 October 1-2, Adelaide, Austra lia Hydraulics in Civil Engineering (IE Aust)

November 23-25, Adelaide, Sth. Australia Hydraulics in Civil Engineering (IE Aust).

October 1-5, Paris, France 18t h Int. Symposium on Remote Sensin g of Environment.

November 27-28, Melbourne, Australia Water Quality Management Symposium .

October 4- 7, Piacenza, Italy Geofluid '84 . October 7-11, Canberra, Australia 'Drill '84', Conference and Exhibition National Waterwell & Drilling Association.

November 28, Sydney, Australia One Day Seminar, Problems of Ex isting Stormwater Drainage Systems (WRFA).

1985

Apri l 28-May 5, Melbourne, Australia 1st International and 11th Federal Convention, AWWA. May 6-9, Burlington, Ontario Toxicity Testing Using Bacteria. May 14-16, Sydney, Australia , Hydrology and Water Reso urces Symposium.

January, Arizona, USA International Congress of !AH

May 16-17, Sa lzburg,tAustria 6th European Conference on Environmental Pollution .

January 14-July 12, Birmingham, UK Water Resources Technology in Developing Countr ies.

June 9-15, Brussels, Belgium 5th IWRA World Congress on Water Reso urces.

October 29-Nov. 2, Monastir, Tunisia 15t h IWSA Congress & Exhibiti on

February 11-14, Melbourne, Australia ' Pol ymer '85'. International Polymer Symposium .

June 10-14, Alexandria, Egypt 3rd International Symposium on Indu strial and Hazardous Wastes .

October 30- ov. 1, Griffith, Australia ANC ID Seminar on Socio-Economic Effects of Irrigation in Australia .

March, Jakarta, lndonesea 1st SE Asian Water Technology Exhibition and Conference.

June 10-15 , Libreville, Gabon 3rd Congress of African Union of Water Supp liers and IWSA Regional Conference.

October 30-31, London, UK Re-use of Sewage Effluent.

April 14-27 , Newcastle upon Tyne, London Management of Hazardous Wastes and Difficult Industrial Effluents.

October 15-17, Bangkok, Thailand !st International Conference on Rural Water Systems . October 22-23, Sydney, Australia Tunnelling Conference (IE Aust).

August 19-23, Melb ourne, Australia International Congress on Hydraulic Researc h .

November 6-9, Adelaide, Australia Multi -objective Planning & Management of Water Resource Systems.

Apri l 16-18 , Coventry, UK 9th Pump Technology Conference.

November 12-17, Johannesberg, S. Africa Water Supply H ydrology.

April 16-18, London, UK Trenchless Construction.

September 4-5, Geneva, Switzerland Technical Conference on the Use of Microprocessors and Microcomputers in Operational Hydrology.

November 22-23, Adelaide, Sth. Australia Seminar, A WW A & IE (Aust) - Changing Management Needs in the Industry.

April 15-19, Melbourne, Australia 8th Australian Symposium on Analytical Chemistry.

September 8-13, Cambrid ge, UK 18th Congress of !AH-Hydrology in the Service of Man. WATER Seplember, 1984

15


Land Management - Key to Water Quality Control R. E. Hartley, D. J. Maschmedt and D. J. Chittleborough SUMMARY This article describes a project currently underway in which the disciplines and philosophies of three organizations are combined to investigate and control water pollution from non-point sources in an Adelaide metropolitan watershed. A 410 ha catchment within the watershed with market gardening as the predominant land use has been identified as a major contributor of nitrogen, phosphorus and sediment pollution to Mt. Bold Reservoir. Soil erosion resulting from conventional land management practices is the main process by which pollutants enter surface water. An understanding of the catchment system is being developed by continuous monitoring of hydrological response, soil loss and land management practices. This information is being used to validate a computer model called ANSWERS for use in the prediction of runoff and soil loss in ungauged catchments, and to evaluate alternative land management techniques for the control of soil erosion. The monitoring , model validation and evaluation of best management practices is expected to continue until 1987.

NON-POINT SOURCE POLLUTION General There is a growing awareness of the importance on non-point sources of pollution throughout the western world . These are diffuse sources such as agricultural, forested or urban land, where pollutants are discharged into waters via di spersed pathways. Unlike point sources, it is diffi cult to allocate blame and therefore to legis late against the offending activity which creates the pollutants. Pollutants include any constituents that degrade water quality, such as sediment , plant _nutrients, herbicides, insecticides and heavy metals. In North America diffuse sources are the major contributors to pollution of water resources (Browne el al 1979). In the United States the Federal Water Pollution Control Act Amendments of 1972 have focussed particular attention on agriculture and forestry. This Statute proposes a means of controlling non-point source pollution through whole catchment land use management. This approach recognises that it is impractica l to control non-point sources of pollution by any legi slation directed to dealing with point sources. It recognises that th e problem mu st be controlled with the co-operation of land managers on the catchment, to obtain the adoption of land management practices that minimize pollution over a large proportion of the area. In Australia, non -point sources have been recognised as major contributors to pollution of water resources. An 18 month st udy of Lake Burley Griffin, A.C.T., revealed that 68 per cent of all phosphorus entering the Lake came from non -point sources compared with only 29 per cent from point sources such as sewage effluent from th e upstream city of Queanbeyan (Cullen and Rosich, 1979). In Queensland, non-point so urces are not only affecting fresh water resources, but also marine resources where rivers laden with sediment from sugar-cane fields flow into the sea (Desmond, pers. comm).

_Adelaide's Water Supply Catchments In South Australia, the sufficiency of water supplies has been a problem since the state was founded. However, more recently, water quality has also become a matter for increasin g concern. The River Murray supplies about 70 per cent of the State's water needs and maintenance of an acceptable level of salinity has a high priority. Furthermore, the watersheds feeding Adelaide's metropolitan reservoirs are mu ltiple land use areas and yield runoff frequently high in suspended solids and plant nutrients.

Rodger Hartley and David Maschmedt are Senior Research Officers with the Department of Agriculture, South Australia. Dr. David Chittleborough is Lecturer, Departm ent of Soil Science, Waite Agricultural Research Institute, S.A. 18

WATER September, 1984

R. Hartley D. Maschmedt Moore (I 974) measured nutrient concentrations in farm dams in small catchments wi thin the watershed of Mt. Bold Reservoir, a major storage in the Mt. Lofty Ranges near Adelaide. The investigation revealed that levels of concentrations necessary to maintain massive algal blooms (see Table I). Critical nutrient levels for eutrophication are 0.3 mg/ L nitrate nitrogen and 0.015 mg/ L soluble phosphate. (Sawyer, 1966). Moore (1974) concluded that agricultural industries could be a contributing cause to D. Chittleborough eutrophic condition of Mt. Bold Reservoir . Since 80 per cent of the catchment of this rese rvoir has an agricultura l land use including cattle and sheep grazing, orchards and market gardens, pollution of the reservoir is predominantly from agri cultural non-point sources. Mt. Bold and other reservoirs wit h catchm ent s dominated by agricu ltural land use, constitute the headwork s of the Metropolitan Adelaide water supply system. They retain loca l surface runoff and are al so used as storages for water pumped from the River Murray. TABLE 1. (after Moore, 1974). NUTRIENT CONCENTRATION IN FARM DAMS RECEIVING WATER FROM PASTURES, ORCHARDS AND NATURAL SCRUB Land Use Pasture Orchards and Pasture Natural Scrub

N03-N (mg / I)

So l. P. (mg / /)

0.10-179 0.09-6 .65 0.02- 0.37

0.04-1.97 0.03 - 0.84 0.01-0.03

Piccadilly Valley Piccadilly Valley is an area of intensive horti culture within the catchment of Mt. Bold Reservoir. Cl im ate, s"i ls and the avai lability of good quality underground water allow vegetable crops to be grown for most of the year. However, a major limitation to this la nd use is th e steepness of the slopes . The comb inati on of an in tense, winterdominant, annual rainfall of 1100 mm and frequent cultivation of steep slopes (gradients up to 30%) co nst itute a major so il erosion hazard. Furthermore, excess ive and ill -tim ed fertilizer appli cations potentially contribute hi gh concentrations of phosphorus and nitrogen to the eroded soil. The valley occupies about 2 per cent of th e overall reservoir catch ment, but preliminary investigation s have indicated that about 30 per cent of the total nitrate enterin g the reservoir comes from this area. The signifi cance of the contribution of sed imen t from Piccadilly Valley to stream and reservoir pollution was furth er hi ghlighted by data collected recently (Chittleborough, 1983). Unit area sediment losses from Piccadilly Valley were five times greater than from Aldgate Creek, a ca tchment of predominantly ubra n land use , and 15 times greater than from Waterfall. Gu ll y, a catchment with nati ve vegetation (see Table 2). As all three catchments occur within the same land and climatic system, so il loss variation s can be attributed principall y to differences in land management. The data show that 95 per cent of the total nitrogen and 91 per cent of total phosphorus in the runoff water are cont ain ed in the sediment fraction rather than in so lution (see Table 3). Since the nutrients are adsorbed by the co lloidal component of the sediment which remain s in suspension, most of the nitrogen and phosphorus in the runoff water reac hes the rese rvoir. It is apparent that so il erosion must be controlled to reduce the nutrient pollution of runoff water whi ch enters Mt. Bold Reservoir from Piccadilly Valley.


Consequently, soil erosion poses a real threat to the continued existence and profitability of agriculture in this area .

STUDY APPROACH In 1980, a co-operative study was begun to investigate the processes of non-point source pollution in Piccadilly Va ll ey and to evaluate modified management practices as a means of controlling this pollution and soil loss. The study team comprises officers from the Depart ment of Agricu lture, the University of Adelaide' s Waite Agricultural Research In stitute (W ARI), and the Engineering and Water Supp ly Department (E. & W.S .).

Department of Agriculture Program The program of the Department of Agricu ltu re is aimed at: the evaluation and promotion of modifed land management techn iques wh ich reduce soil erosion; • the validat io n of an ex ist in g predictive model for describing t he relationships between land management and non-point source pollution. These aims will be achieved through monitoring and research programs currently under way. The monitoring program is based on a series of instrumented gauging stations which continuously record stream water level and rainfall. Water samp les, co llected automatica ll y in response to stage hei ght changes are analysed for sed iment loading and nitrogen, phosphorus and carbon concentrations. Soil and crop management surveys have been carried out to provide information for the input files of a model of physical processes called ANSWERS. (Beasley and Huggins 1981). ANSWERS (Areal Nonpoint Source Watershed Environment Response Simulation) is a model intended to simulate the behaviour of watersheds having agr iculture as their primary land use, during and immediately follow in g a rainfa ll event. A fundamental characertistic of the model is its distributed parameter approach, as constrasted to the more common lumped parameter models. This distributed parameter model incorporates spatially variable parameters of the catchment in its operation. This is achieved by app lyi ng a grid of square cells or "elements" to a map of the catchment , and characteris ing the topography, so il s and la nd management within eac h element. The model output in response to a specific rainfall event includes the following information: • cumulative di scharge and sediment loadings at the watershed outlet over a period of time from the initiation of, rainfall. • net transported sediment yield and deposition for each element. • channel deposition. The compariso n of predicted and recorded runoff a nd eros ion is essent ia l for validation of the model. The co mprehensive instrumentation and data base which have been establishe8 in the Piccadilly Valley provide an ideal opportunity for this validation process. The model can then be used to predict with confidence the response to rainfall •

Sediment in H-flume after storm event. Total movement of soil and nutrients is greater than indicated by the data presented in Tables 2 and 3, as these refer only to the very fine grained and co lloidal material (0.2-5 microns). Coarser material eroded from the hil l slopes is deposited on lower slopes and in drainage ·lin es, and although lost from the field is not a lways recorded in runoff water. TABLE 2. (after Chittleborou gh, 1983). SEDIMENT YIELDS FROM ALDGATE, PICCADILLY AND WATERFALL GULLY CATCHMENT, 1982 Carchmenr Piccadilly Aldgate Waterfall Gully

Area (ha)

Dominanl Land Use

Annual Sedimenr Yield (kg / ha)

410 830

Intensive horticulture Urban Virgin scrub

2362 480 157

500

TABLE 3. (after Chittleborough, 1983). ANNUAL YIELD OF NURTIENTS FROM PICCADILLY VALLEY Form of Transporr Nurrienr Nitrogen Phosphorus

Sedimenl (ka / ha)

Solurion (kg / ha)

Tora/ (kg / ha)

19.0 5.8

I.I 0.6

20.1 6.4

Soil erosion losses are most severe during storm events. In 1982, two high intensity storms, on March 22 and August 11, caused large losses of sediment during the span of severa l hours. Table 4 shows that 56% of the annual sediment loss from Piccadilly Valley occu rred during these storms wh ich produced o nl y 7% of the annua l flow. However, no accelerated erosion occurred in the natural vegetated catchment of Waterfall Gully. At the peak of a 24 hour storm with a return period of only 2 years in July 1981, eight tonnes of sediment per minute were being lost from the Piccadilly Valley (Chittleborough, per. comm.). It is apparent that dramatic so il loss from this area can result from comparatively frequent storm even ts . Over the 100 years or more that the area has been farmed, up to 30 cm of so il have been eroded from the slopes. This loss is above a to.lerab le level given that the topsoil is less than 40 cm deep. At the present time cu lti vation of eroded slopes is bringing subsoil clays to the surfa ce. This resutls in a reduction in the hea lth and vigour of crops . TABLE 4 . (after Chittleborough 1983). PROPORTION OF ANNUAL LOSS OF SEDIMENT CAUSED BY TWO STORMS ON MARCH 22 A D AUGUST 11, 1982 Ca1c/11nen1 Piccadilly Aldgate Waterfa ll Gu lly

Sedimenr loss (lonnes)

Propor1ion of annual loss (%)

Propor1ion of annual flow(%)

539.9 102.2 0.25

56 26

7 8 2

Erosion gutter in over-cultivated soil. WATER Sep/ember, 1984

19


E&WS Department

o f water q uality in Mt. Bo ld Reservoir has led to the Depa rtment' s in vo lvement in thi s project. The Departm ent h as suppl,ed m o st the record ing instrume nts fo r th e catchme nt m o nit o ring progra m a nd is respo nsible fo r admini stratio n of the Natio na l Water Resources Assessm ent P rogra m fu nds whic h pa rtly support the p roject.

De11artm ent of Agriculture

Prob le.m identific~tion

Modelling-..,;

Techn ical e xpert ize ~

Monitoring).._._ _ __

DISCUSSIO N

Best management practice

The Pi cca di lly Val ley stu dy has a u n iq ue blend of p hil osop hi es w hic h is re fl ec ted in t he d isc iplin es o f the o ffi ce rs in vo lved a nd in th e ma nage me nt o p tio ns avai lab le to so lve th e prob le m s of so il eros io n a nd wa te r po llut io n . One poss ib le a pp roach is to e m p loy a k nown method for so lvi ng th e problem, t he re b y achi ev in g rap id result s . W hil st thi s opt io n has the ad va n tage of p rod ucing a degree of s uccess in the sho rt ter m , suc h dec isio ns are usua ll y m ade o n lim ited da ta a nd co nsequ e ntl y may n ot prov ide sa ti s factor y lo ng term so lu tio ns. Anot he r a p p roac h is the in ves tiga ti on of the processes o n no n-po int so urce po ll u tio n , eva lu a t in g th e ava il a ble ma nage me nt opti o ns o n a n experi me nt a l basis , an d so e nla rgin g the d a ta base fo r dec isio n m akin g . Th e two p h ilo sop hi es fo rm a feedbac k relat ion shi p. For in sta nce, a k n ow n m eth od of co n tro lling runo ff a nd e ro sio n is to red uce till age by usin g herbi ci d es to contro l weeds. T here is littl e do ub t th a t th is ma nageme nt alte rn a ti ve w ill red uce eros ion a nd sat isfy the objecti ve of so il co nservatio n . H owever, will suc h tec hniqu es be accepta bl e to th e g rowe rs w ho m ust m a intai n cro p p rod uctio n leve l? Furt her m o re, will such p ract ices resul t in o ne po llu ta nt , in the fo rm o f suspe nded so li d s a nd p la nt nu tri e nt s, sim ply bein g replaced by a no th er, na mely he rb icides? In o rder to full y eva lua te thi s co ncept of po ll uti o n co ntro l, it will be necessa r y to a ssess t he agro no mic aspects of red uced till age sys te m s a nd to in ves ti ga te th e process of herb ic ide t ra nsport in th e so il a n d wate r sys te ms . Th e in tegra ted ro les of th e participat ing o rga ni zat ions are sum marized d iagra m mati ca ll y in F ig u re I : T he lo n g ter m obj ecti ve o f th e p roject is a set o f best m a nageme nt practi ces fo r the co nt ro l of no n-po int sou rce po ll u ti o n in m etro po li ta n

Funding

S

assessme~t

WARI

Growers

~ n t lflcatlon of processes

Adoption

Influence of land use - - - - - - - - - - -

fi gure

I.

Int egration

of

A cti viti es Proj ect.

in

th e

Piccadill y

Va ll ey

eve n ts in o th er simi la r catc hme nt s whi c h a re subj ect to c h a n ging la nd ma nage m ent , o r w hi c h req u ire c ha n ges in land m a nagem en t to all ev ia te a n ex isting po llut ion to eros io n problem . The resea rc h aspect of th e progra m is foc uss in g o n t he eva lu ation of . mo di fed la nd m a n age m ent practi ces whi ch h ave the poten t ia l to red uce erosio n . If th ese necess ita te a cha nge from traditio na l far mi ng met h o d s , th e co-operatio n of the m a rk et ga rde ners in the a rea will be necessa r y fo r the m to be a d opted wide ly. Th ey woul d need to have im med ia te eco n o mi c be ne fit s to be a tt racti ve to the lan dh o ld ers . Wa it e Ag ri cultural Research Institute Program

Th e WA RI team is in ves ti gatin g th e fund a me n ta l processes of sedi me n t a nd nutri ent re m ova l by st ud ying in d etail th e m echa ni sm s of move m en t of co ll o id a l m ateri a l fro m th e soil pro fi le in to the hyd ro logic sys tem. A co mpa riso n o f wate r q ua lit y fro m a ra nge of catc hm etn s w ith co n tra sting la n d uses is a n integra l part o f thi s st ud y.

Role of th e Engin eering and Water Suppl y Department Th e E. & W . S. Department is respo nsible fo r ma intena nce of accept a ble qua lit y supplies for d o m est ic use . Co ncern a bo ut the deteri o ratio n

CONTINUED ON PAGE 24

STRATEGY FOR TH E CONTROL OF NON POINT SOURCE POLLUTION FROM AGRICULTURAL LAND 6 . Adoption of BMP ' s for contro l of NPS Pollution in metropolitan watersheds

Ed u ca ti o n faci li ty M o n it orin g for t er ti a r y +- ----- of run o ff a nd s tud e nt s p o llut a n ts

Ex t e ns io n Se rvi ces

Best Management Prac t ice s (BMP ' s) for control of Non Point Source (NP S) Pollution in Water Supply Catchment s

1. Eva luat ion of NPS Po llu tion under current land management pra ctic e s

Ve rifi ca ti o n o f ex i sti ng NP S m o d e l Fi e ld tri a l s

2 . Id e ntification of BMP ' s

Se l ec ti o n fr o m m o d e l pr e di c t io n s

5 . Prediction of NPS Pol lution and contro l measures in catchments without in s trumentation

Pr e di c ti ve m o d e l

4.

Mon it o rin g pr ogra mm e

l

Adoption of BMP ' s in Piccadil l y Va ll e y

E xte n sio n se r v i ces

L a nd m a n a g e m e nt s ur vey

r ev i e w Li t e r a tur e

M o n i t o ring pr og r amm e

V e r i fi ca tion o f m o d el

Figure 2. Strategy for the control of non poin t source pollution from agricultural la nd. WAT ER Seprember, /984

Eva l ua ti o n of pr ese n t sys t e m ( mo nit o r in g pr og r a mm e )

3 . Eva lua tion of NPS Po llu tion under BMP ' s

Ve rif icati o n of model

20

L a nd m a n age m e nt s ur vey

En v ir o nm e nt a l e ff ec t s - imp ac t of h e rbi c id es

1 I l


DISINFECTION OF WATER FOR CONTROL OF AMOEBAE B. S. Robinson and P. E. Christy INTRODUCTION Primary amoebic meningoence phalitis (PAM), know n po pular ly in A ustrali a as 'a moebic meningiti s', is a severe in fect io n ca used by th e free- li ving a moebo flagellate Naeg leria jowleri. Since recogni tio n of th e di sease at the Adela ide C hild ren 's Hospita l, cases have been described from fo ur states of A ustra li a and fr om th e USA , So uth America, Brita in , E urope, New Zea land, Africa an d Ind ia. While it is a very uncommon di sease, t he mo rta lit y in recogni zed PAM cases is abo ut 98 per cen t. Publi c a nxiety in a reas and season s where cases ca n occur is often hi gh , and detai led p ress coverage of in dividua l cases occurs. Of the A ustralian cases, 70 per cent have occurred in th e mid - a nd upper-north of So uth A ustra li a (approx im ate ly IO per cent of th e wo rld cases). PAM is waterborne, associated with bathing water whi ch reac hes temperat ures aro und and abo ve 30 °C, rather tha n with d ri nk ing water. In t he USA, most infections have been associated with natural or semi-nat ura l fres hwater bodi es (John , 1982). In Europe, sources of infect io n have includ ed heated swimm ing poo ls (Cerva, I 97 I) and t herma lly polluted natura l waterways or canal s (va n den D riessche et a l. , 1973). In Bri tain and New Zealand, cases have been associated with natura l therma l water (Bath Public H ealth Lab., 1978 ; Brow n et a l. , 1983) . A ustra lia is the o nl y country where cases ha ve been li nked with ret icul ated wa ter or where N. jowleri has been d etected in pub lic wate r supplies (Dorsch et a l. , 1983). For a uni cellul ar organ ism, N. fowleri has a complex li fe cycl e, with three fo rms : the a moeboid stage or trophozo ite (phagocytic feedin g, prolifera tion) , the fl age ll ate (h ighl y mot ile, no feeding or pro li feration) a nd the cys t (i nact ive, relat ively res ista nt to adverse co ndi ti o ns). The li fe stages have im porta nt ro les in t he seasona l behavio ur of N. jowleri popu la tions and in th ei r d ispersal (Griffin , l 983). invo lvement o f swimmin g poo ls and water supplies in some countries sugges ts th at those infections shou ld be preventa ble by a deq uate disinfection . There are confl ictin g reports in th e medical a nd micro biological literature concern ing th e effecti veness of chl o rine, th e chemi ca l most widely used for water di sinfecti on, in contro lling N. fowleri. Labora tory stud ies have shown th a t N. jowleri trophozoites and cys ts are susceptible to fr ee chlorin e (Curson s et al., I 980; de Jon ckheere and van de Voorde , l 976; Robinso n , I 977). H owever, confusio n has a risen beca use of the apparent fai lu re of chl or ination in the circumstances lea ding to some of th e in fections, and because of lack o f understandin g of the cond itio ns required for chl o rine to be effective against N. jowleri. This paper di scusses t he susceptibili ty of N. jowleri exposed to chl orine a nd related di sinfec tants a nd prese nts da ta from field surveys to show the e ffectiveness of di sinfec tion in South Au stra li a n water suppli es. T he effectiveness aga inst N. fowleri of other di sin fec tion processes used for drinkin g a nd bathing water will a lso be di scussed. Reports of infect ions (or iso la ti ons of N. Jaw/en) associa ted with 'disin fected' water will be reviewed, with comm ents o n th e cond iti o ns requ ired for adequate di sin fect ion. For comparative purposes, some laboratory data co ncerning a moebae in the unrelated genus Acanthamoeba will be in culded. Acanthamoeba species have been res po nsib le for a number of hum a n infection s of va r¡ying sever ity. Wh il e few of the infect ions a ppea r to have been waterborne, Acanthamoeba a re widespread in so il and in fre sh and sa lt water.

been studied to assist with decision s abo ut chl orine doses for supplies where thi s organi sm may occu r. C hl oramination is a di sinfec ti o n option being considered fo r extensive country water suppli es, ow ing to the relati ve sta bility of th e chloramines produced. To prov id e a background fo r fi eld tri a ls of chloramination, the suscept ibility of N. jowleri to monochl oram in e, the preferred B., Robinson chemical product of chl orami natio n has a lso been stu d ied. N. jo wleri trophozo ites a re killed ra pidly by free chlorine, with contact times for 99 per cent mortality (t.,) varying with concent ratio n (Figure l) . The tim e course of disinfection is a short lag phase (diffi cult to measure for free ch lor ine), fo ll owed by acceleration to an expo nentia l ph ase whi ch approx im a tes a fir st-ord er chemi cal reaction. No significa nt clumpin g of trophozoites occ urs, so th e lag phase presum ab ly rep resents a finit e tim e re_/ quired for penet ration of th e cell whi ch is p . Christy bulk y compa red with th e size of bacteri a and viru ses. N. Jowleri cys ts are less susce ptibl e to ch lorine than troph ozo ites, with longer lag ti mes at co m parab le doses (Figure 2) . In cys ts of a related nonpa thogen ic amoeba , Naegleria gruberi (shown for co mpari so n), t he lag ph ase is lo nger still. Since N. gruberi cys ts are a lso more resistant to desicca tion , it is lik ely tha t th e perm ea bility of th e cys t wa ll to sma ll mo lecules determ in es at least the initia l kinetics of disinfection. Figure 3 illu strates th e relat ion shi p of t 99 to in iti a l co nce ntrati on fo r N. Jo wleri troph ozoites a nd cysts ex po sed to fre e chlorine a nd monochl orami ne. Monochl oramin e a cts more slow ly on N . fow leri, as it d oes on other micro-organi sms. In ex perim ents with trophozo ites , t99 was a pprox imately three times longer th a n with t ree chl ori ne at equi valent concentrati o ns . T hi s rat io is lower tha n is genera ll y report ed for mortality of bacteria a nd viruses whi ch is 20 to 80 times slower with chl oram in es (Whi te, I 972). T he rela ti ve susceptib ility of N. jowleri cfs ts to th e two disinfecta nts is mo re diffi cul t to int erpret, owing to the greater d ecay of th e free ch lorin e over the lo nger contact tim es required. Below a give n initia l conce ntration (in t hese experi ments, I .3 mg.L- 1 ) , the decay o f fr ee chl ori ne was suffi cie nt for N. Jowleri to be kill ed more slow ly than by monochl oram ine. In ge neral, th e 'crossove r' concentrat io n will depend on the chl o rin e a nd chl ora min e dema nds, pH and temperatu re, whi ch deter m ine the decay rat es . A more effecti ve measure of ex pos ure to th e di sin fectant wou ld be an int egrati o n of the cha nging co ncentrat io n with time. At prese nt, we a re developin g such a n ' integrated dose ' mod el fo r control of N. fow leri by th ese dis in fectan ts. Th e known sta bility of monochloramin e a nd a stud y of chl oram in e decay rates in water fr o m the Ri ver Mu rra y sugges ted that chl oramin a ti o n would be a suit a bl e d isinfec tion process for co nt ro l of N. Jowleri in ex tensive rural wa ter suppli es, pro vided that th ere is sufficient contact tim e before t he first dom est ic services.

SUSCEPTIBILITY OF NA EGLER/A FO WLERI TO CHLORINE AND MONOCHLORAMINE

SUSCEPTIBILITY OF ACANTHAMOEBA SPECIES TO CHLORINE

Most So uth Austra lian water suppli es a re di sinfected by conventiona l chlorination , a nd suscep tibilit y of N. jowleri to chl o ri ne has been studi ed to ass ist with d ecisions abo ut chlorin e doses for sup pli es

Fata l Acanthamoeba infection s, a n encep ha li tis m ore protracted than PAM , have been repo rt ed in severa l co untr ies , includi ng a case in Austra li a (Ca rter et a l. , 1981). Nonfata l infec tions have a lso occ ur red , mos t common ly eye ulcerat io n oft en leading to perma nent loss of sight. The suscept ibili ty to chlorin e of cys ts of a n Acanrhamoeba st ra in (polyphaga gro u p) is compa red to th a t of N. fowleri cysts in Figure 4. Acanthamoeba strain s in thi s gro up, whi ch is defin ed by cys t st ru cture, have been respo nsible fo r several of the eye infect io ns. At the

Bret R obinson is Senior Scientist, Amoebae Research with the State Wa ter Laboratory of the Engineering and Water Supply Department, South A ustralia. Peter Christy is Microbiologist with the Amoebae Research organisation.

r

WATER Sep tember, 1984

21


100

,, ,

tio n of a num ber o f chl o rin a to rs in th e Morgan-Wh yalla system has led to sa ti sfacto ry co nt rol of Naeg leria spec ies in water supplied to tow ns where P AM cases have occ urred (Wa lters et a l. , 198 1) . Acan 1hamoeba species a re th e most common a moa bae detected a t th e high fr ee chlorin e levels immedi ately after chlorin a ti on at several of th e stati ons. No infecti ons by th ese o rga ni sms have been a ttributed to contact wit h publi c water suppli es. Late in the 1980-8 1 summer, N. fow leri was detected in water supplied to a number o f count ry a reas from t he Ri ver Murray. The conta mina ti o n was parti cularl y wid espread in th e Yo rk e Peninsula supply, a nd emergency co ntro l meas ures were introduced. Th e meas ures included di sin fecti o n of indi vidua l storage ta nk s a nd continuous chlorin ati o n using mobil e pl a nt whi ch has since been replaced by pe rma nent stati o ns . Figure 5 shows th e di stributio n of free chlorine a nd o f co nt a min ati o n by N aegleria species three wee ks a fter commencement of the emergency meas ures. Naegleria isola tio ns were limit ed to a reas not reac hed by a t leas t 0. 5 mg .L· 1 free chlorine . Further monitoring showed progress ive improvem ent in mi crobiological qua li ty, including reduced incidence o f a moebae . However it was not possible to eradica te N. Jowleri fr om thi s suppl y for severa l reaso ns . Even with three chlo rinatio n po ints, continuo us di sin fect io n o f th e ex tremiti es was no t practical with o ut un accepta bl y high chlo rin e resid uals in ot her pa rts of the sys tem . Furtherm ore, th e sediment accumul a ted in storage ta nk s protects the a moebae from di sinfecti o n a nd provid es bac terial nutrients . N . f owleri has been detected in sediment coll ec ted fr om tank s du ring cleanin g at densiti es as high as 4200 per gra m d ry weight. Wi t h such potenti al sources of con tamin atio n within a water suppy, continui ty a nd pers istence of dis in fec ti on a re clearl y import a nt in co ntro lling N. fow leri . A tri al o f chlora minati o n was co ndu cted in the York e P enin sula suppl y from November 1983 by adding a mmoni a a t th e existin g

....

II

I I I I I I 11 I I I I

\

\

\

\ \ \ \

10

a, Cl

ro

initial concentration

i:a, u

ai

a. 1-0

0

2

6 8 4 Contact Time , min.

10

12

Figure 1. S usceptibility of N. fowleri trophozoites to free chlorin e at three initial conce ntrations (dem a nd-free med ium , pH 7.0, 30°C).

rela tively hi gh chlo rine d oses used in this experim ent, N. fow leri cysts were killed rap id ly, but 50 per ce nt of A . p olyph aga cys ts survived after o ne ho ur . Whi le th e repo rts of Acan1ham oeba infec tio ns have been even less freq uent tha n cases of P A M a nd few a ppear to have been waterborne , th ese o rga ni sms are of interes t beca use o f their res ista nce to a range of ph ys ical a nd chemi cal condi tio ns.

10 N.fo wleri

CONTROL OF AMOEBAE IN WAT ER SUPPLI ES T he prim a ry purpose of disin fec tion of publi c wate r suppl ies is usuall y to prevent ent eri c in fec tio ns by bacteria a nd virsues. Disin fectio n is co nsidered adequate prov ided th e numbers of these pat hogens (or of a ppro pri ate indicator organisms) are redu ced below certain levels, around whi ch na ti o nal a nd int ernati o nal stand a rds for water qu alit y a re based . In ad diti o n to requir ing hi gher chlorin e concentra tio ns a nd / o r lo nger contact tim es fo r cys t des tru ctio n th a n a re required to kill most bacteria a nd viruses, Naegleria a nd Acanlhamoeba species prese nt ot her di ffic ulties . Amoebae may multipl y fr o m ex tremely low densities (undetecta ble in the la bo ra to ry) if the di sin fecta nt does not persist, because they a re fr ee- li vin g. Do ub ts abo ut th e a bility o f chl orin e to contro l N. f o wleri da te fr o m the fir st report o f thi s orga nsim from reti cul a ted wa ter in So uth Austra li a (Anderson a nd J a mieso n , 1972). The wa ter supplied to P ort Augusta was descr ibed was ' unin fi ltered , chl orin a ted river water' . At th a t time, however , water pum ped fro m th e Ri ver Mur ray a t Mo rga n was chl o rin ated continuo usly a t low doses (probably less than the dema nd ) a nd 's lug d osed ' for bri ef peri ods each week to preve nt fo ulin g of th e pipelin e . Sin ce th e wa ter is pumped 280 km fr o m the source (d etention tim e fr equ entl y seven days or lon ger) , it is cert ain th a t free chl or ine did not pe rsist as far as P o rt Augusta . Su bsequ ent in sta ll a22

WAT E R Sep rember, /984

1-0 - - - - - - - - - - - - - - - - - - - - -

- - - - - -

0-1 ,...__ _~ - - ~ - - ~- -- ~ - -~ - - ~ 10 2 4 6 8 12 0

Contact Time , min. Figure 2 . Susceptibility of N. Jowleri and N. gruberi cysts to free chlorine, initial concentration 2.0 mg . L· 1 (demand-free medium, pH

7.o, 30°c).


100

100

A. polyphaga

10 10

trophs , NH 2 CI

(/)

(1)

\

:iC:

.E

Cl)

E i=

... ...

ro

-~ > ....

:,

cysts , free Cl

trophs , free Cl

>,

~

ra

0

~

1-0

"'

a, a,

~

Initial

1-0 Chlorine , mg .L- 1

1-0 N. fow/eri

(1)

Cl

ra

c

(1) (.)

ai

a. 0-1

o~.___ ___._ _.__.____.__,_~~-- ~-~~~_,_~ 0 .1

Cl)

10-0

Figure 3 - Susceptibility of N. fo wleri trophozoites and cysts to free chlorine and monochloramine: 199 vs initial concentration (dem and free medium , pH 7 .0 , 30 °C).

chl o rin a ti o n sta ti o n a t P askevill e . Control of pH , whi ch was generall y alkaline, was no t at tempted a nd fi eld residual meas urements d id not differenti a te th e chlo ramin e species . C hlora min es spread t hrou gh the suppl y progressively ove r severa l wee ks; mo nitoring permitted chl o rination a t the supplementary sta tions to be turn ed o ff as the chl ora mines a rri ved . Figure 6 shows th e di stributio n of chlora min es at the end of Jan ua ry 1984 wit h the d istribu tio n of N. fowleri iso lated during th e 1983-84 summ er. N. Jowleri was no t detected a t a ny locatio n reached by chl o ramin es . H owever th e organism reached a densit y of 2 700 per litre a t Edith burgh sho rtl y befor e a rri val o f the di sin fec ta nt , a fter which its numbers fell 10 000-fold within 48 hours . C hloramina tion fulfilled th e requi rement for persistence a nd co nti n uit y of disinfectio n in the extre mi ties o f thi s supply more effecti ve ly tha n had co nventio na l chl or ina ti on, a nd hence co ntrolled N . fow leri mo re successfull y. Qu est io ns abo ut potential hea lth effects of chl o ramin es a nd chl o ra minat io n byprodu cts still need to be resolved.

0

20

40

60

80

Contact Time , min. Fig ure 4 - S usce ptibility of cysts of A ncantham oeba sp. (po lyphaga group) a nd N. fow leri to free chlorin e, initital con centration 4 .0 mg.L· ' (de ma nd free medium , pH 7.0 , 30° C).

Main tai nin g continu o us co ntact between the disin fecta nt and all potentia ll y co ntamin ated sur faces in t he pool system appears to be a major diffi culty in co ntrolling N. fow leri in swimm ing pools . Protecti on of mi cro-o rga ni sms by o rga ni c ma teria l acc umul a ted o n the surface of the poo l filt er has also been d~mo nstra ted (Warren a nd Ridgway, I 978). Densities of a moebae washed fro m the filt er d urin g

DISINFECTION OF SWIMMING POOLS A number of PAM cases have been associated wit h sw imming poo ls where di sin fect io n fa iled to cont ro l t he a moebae . In Czechos lova kia, 16 cases occur red betwee n 1962 a nd 1965, associa ted with a sin gle poo l. Conta min a tion by N. fow leri occurred repeatedl y despi te free chlorin e residual s around 0.3 mg. L- , (Cerva, I 97 1). C hl o rin a ti o n practi ce was improved , but a rec urrence of the conta minatio n in th e mid - I 970s led to mo re deta il ed in vest igati o n . A co ncea led water-fill ed cav it y a bo ut 100 mm wid e was d iscovered behind one wa ll of the pool, where a moebae co ul d sur vive a nd mul tiply, iso lated fro m the chl or ine in t he pool (Kadlec et al. , I 980) . In fect ive a moebae were a ppa rently in troduced to th e pool durin g cha nges in water level. A single case occurred in simil a r circum stances in Ba th , Engla nd in 1978 . In t hi s in sta nce, untreated wa ter from a th ermal spring ga in ed access to the poo l t hrough a gratin g in th e noo r (Bat h P u bli c H ea lth La borato ry, 1978) .

Chlorination Free chlorine :!' 0 -5mg.L"1 •

Naegteria sp. present

F igure S. Yorke P eninsula Wa ter Supply, South A ustralia . Distribu tion of free c hlorin e residu al a nd Naeg leria species, 17-18 .2.8 1. WATER Seprember, 1984

23


Chloramination Combined chlorine :!0 0-Smg . L- 1 •

N. fowleri present

Figure 6. Yorke Peninsula Wa ter Suppl y, South Australi a. Distribution of combi ned chlorine residual (24.1.84) and N. fowle ri (Jan uaryMarch, 1984) . backwas hing ca n reach ma n y t h ousands per li tre (Lyo n s a nd Kapur, 1977), a nd th ese organi s m s may be introduced to t h e poo l durin g periods of inadequate d is infectio n . Sat is factory co n tro l of amoebae h as been reported in well mainta ined, brom in ated sw imming pool s . Ho wever, h ydrot h erapy pools in Belgium w hi c h u sed c irc ul atio n t h ro u g h an ultra-v io le t light system a s the h ole m ea n s of dis infect ion were p ersiste ntl y co nt a minat ed by Naeg leria sp ecies (de J o n c kh eere, 1982). Acanthamoeba species are occas iona ll y detected in pool s at hi g h free c hlorine levels . T h e ir m edica l s ign ifica n ce is diffic ul t to a ssess . In a r ecent report of an eye in fect io n , a spa poo l was identified a s t h e likely source of infect ion (Samples et a l. , 1984), and an un completed sur vey of s p a pools in South Au stra li a has sh ow n co n s iderable contam in ation by Acanthamoeba spec ies. Th e abil it y of Acanthamoeba to infec t ex is tin g wo u nds s u ggests t h at u se of s uch pools for hydrotherap y, in parti c ul a r , cou ld lead to infect ion.

CONCLUSIONS The pathogen ic amoeboflagellate Naegleria fow leri is su scept ible t o ox idative dis infecta nt s s u c h a s c hl orin e and monoch loram ine. Under favo urabl e co ndition s, thi s organi s m can multipl y fr o m extremel y low numbers that ma y h ave s ur vived initial d isin fection . Cyst s of Acanthamoeba species a re more res is ta n t to d is infection , but t h e ir sig nifi ca n ce a s co ntamin a nt s of water is uncerta in. Co ntrol of potentially pathogen ic free- li v ing a moebae requ ires continuity and p e rsis te n ce of d is infection throug h out a water suppl y or swim ming pool.

REFERENCES ANDERSON, K. a nd JAMIESO N, J. A. ( 1972). Primary a moeb ic menin goencephalitis . The Lancet I : 902. BATH PUBLIC HEALTH LABORATORY (1978). Primary amoeb ic meningoen ce ph a lit is. Bath, Somerset. Commun ica ble Disease Report 78/ 42. BROWN, T. J ., CURSONS, R. T. M., KEYS , E. A., MARKS, M. a nd M ILES, M. ( 1983). Th e occ urence and distribut ion of pat hogen ic free-liv ing amoebae in thermal areas of the Nort h Island of New Zeala nd. N.Z.J. Marine and Freshwater Research 17: 59. CARTER, R. F., CU LLITY, G. J. , OJEDA, V. J ., S ILB ERSTE IN, P. and W ILLAERT, E. ( 198 1). A fatal case of men ingoen ce phalitis due to a freeliving amoeba of uncertain identit y probably Acanthamoeba sp. Pathology 13: 51. 24

WATER September, /984

CERVA, L. (197 1). Studies of limax amoebae in a swimming poo l. Hydrobiol. 38: 141. CURSONS, R. T. M .. BROWN , T. J ., and KEYS , E. A. ( 1980). Effect of disinfect ion on pathoge nic free- li vin g a moebae in axenic cond itions . Appl. Env. Microbial. 40: 62. DE JO NCK HEERE, J. F. ( 1982). Hosrital hydrotherapy poo ls treated with ultra vio let light: bad bacteriological qua lity and presence of thermop hilic Naegleria. J. Hygiene 88: 205. DE JONCKHEERE, J. F. and VAN DE VOORDE , H . (1976). Differences in destruction of cysts of pathogenic and nonpa1 hogen ic Naegleria and Acanthamoeba by chl orin e. Appl. Env. Microbial. 3 1: 294 . DORSCH , M. M., CAMERON, A. S., and ROB INSON, B. S. (1983). The epidemiology and co ntrol of primary amoebic meningoencepha litis wit h particular reference 10 South Austra lia. Trans. Roy . Soc . Trap. Med. Hyg. 77: 372-377. GR IFFIN, J_ L. ( 1983). The pathogenic amoeboflagellate Naegleria fowleri: envirnmental isolatio ns, competitors, ecologic interact ions. and the flage llate-emp ty habi tat hypothesis. J. Proto zoa /. 30: 403. JOH N, D. T. (1982). Primary amoebic meningoencwphaliti s and the biology of Naegleria fowleri. Ann. Rev. Microbial. 36: 101. KADLEC , V., SKAROVA, T., CE RVA , L. a nd NEBAZN IVA , D. (1980). Virulent Naegleria fowleri in indoor swimming poo l Folia Parasitol. 27: 11 . LYONS , T. B. a nd KAPUR , R. (1977). Limax a moebae in public sw imming pools of A lban y, Schenec tad y a nd Re nsselaer Counties, New York: their concentr_at ion , correlations and signficance. Appl. Env. Microbial. 3: 55 1. ROBI NSON, B. S. ( 1977). Effect iveness of chlorine in the contro l of Naeg leria: laboratory a nd fie ld studies in South Australia. Proc. 7th Fed. Conv. Australian Water and Wastewate r Assoc . : 465. SAMPLES, J . R., BIN DER, P S., LU IBEL, F. J. , FONT , R. L., VISVESVA RA, G. S. , a nd PETER, C.R. ( 1984). Acanthamoeba kerat itis, possibly acquired fro m a hot tub. Arc hi v. Ophthalmo l. 102: 707. VAN DEN DR IESSC H E, E. , VANDEPITTE, J ., VAN D IJ CK, P. J. , DE JO NCK HEER E, J. a nd VAN DE VOORDE , H . (1973). Primary amoebic meningoencephalit is after swimming in stream water. The Lancet 2: 97 1. WALTERS, R. P. , ROBINSON, B. S., and LAKE , J . A. (198 1). Experiences in the control of Naegleria in public water supplies in South Australia. Proc. 9th Fed. Conv. Australi an Water and Wastewater Assoc ., Sec tion 3: I . WARREN , I. C. and RIDGWAY , J. ( 1978) . Swim ming poo l disinfection. Water Research Centre Tech nical Report TR90, U.K. WH ITE, G. C. (1972). 'H a ndbook of Chlorination ' (Va n Nostra nd Reinhold, N.Y.).

R. HARTLEY, D. MASCHMEDT and D. CHITTLEBOROUGH continued from page 20 waters hed s . The strateg y for th e ac h ievement of thi s objective is diagramat ica ll y re presented in Figure 2. Activ it y is cu rre n1l y con centrated in stages 1, 2 and 3 and by 1987, t~ anticipated completion date of the project, stage 4 wi ll be underway. Exten sio n of the strat egy int o stages 5 and 6 w ill occ u r in respo n se to the indent ification of nonpoint s ource po llu tio n prob le m s in th e futur e. The a nti c ipated b e n e fits res ultin g from th e s tud y include: • protect ion of th e soil res ources of th e area, leading to improved long ter m p r o spect s for h orticultura l prod u c ti on: • sub stantial reduction in the costs of water purification, part ic ularly filtr a ti on and copper s ul phate treatment: • a mo re h ea lth y aquatic env ironment: • availab ili ty of a pred ictive co mput er mod e l, w ith the faci li ty to re li ab ly ident ify exist in g or potential non-po int po ll ut ion problems a n d so lutio n s more qu ick ly and c h ea pl y than is poss ible a t prese nt.

REFERENCES BEASLEY, D. B. and HUG G INS , L. F. ( 1981). ANSWERS Users Ma nual. U.S. E nviron ment al P rotect io n Agency - 905 / 9-82-001. BROWNE , F. X. and G IZZARD, T. J . (1979). Wat er pollution . Non-point sources. J. Water Pollution Control Fed. V5 1(6): 1428- 1444. C HITTLEBOROUGH . D. J. ( 1983). The Nutrient load in surface waters as influenced by la nd use patterns. Proc. of a Symposiu m - The Effects of Changes in Land Use Upon Water Resources. A.M.F., Glenside, May , 1983: 42-53. CULLEN, P. a nd ROS IC H , R. ( 1979). Effect s of ru ral a nd urban sou rces of phosphoru s of Lake Burley Griffen. Prag. in Water Tech. V/1(6): 2 19-230. MOORE, S. D. (1974). C hanging Lan d Use Increases Nitrogen and P hosphorus Concentratio ns in Farm Dams. Soil Conservat ion Branch , Department of Ag ri c ulture, Sout h Au stralia S l4/ 74 . SAWYE R, C. (1966). Basic concepts of eutrop hication. J. Water Pollution Co ntrol Fed. V38(5): 737-744.


Water Treatment for the Northern Towns of South Australia R. C. Thomas ABSTRACT The Ri ver Murray is th e major source of water for the ' Iro n Triangle' cit ies of Wh ya ll a, P ort A ugusta a nd Port Pi rie a nd for other nort hern town s of South Australi a and tow ns in th e Barossa Valley, the midnorth and Yorke Peninsula. The co mplex water suppl y system for this region ex ten ds over an a rea in excess of two mi ll ion hec tares a nd serves a popu lation of a bo ut I 20 000 people . A major wo rks progra mm e for the treatment of the water suppl ies fo r the ' north ern towns of Sout h Austra lia ' has no w commenced with the co nstru ction of the Mo rga n water filtration plant.

had little or no ca pacity to provide water for stock and ot her farmin g requirem ent s. As a result a nd quite ear ly in the hi story of

R. C. Thomas LEGENO Northern Towns Water Ois l ribu tion Area ProL>O~l!ll Wi,it1,r F1lt , .,1wn Pl<>nl

Sto,aye Rese, so"

Iron Knob

Sc, v,ce

AtStfVO!I

Pump,og Station

<I.

D

...• ...

M a 1o, P 1pehne

1.0 INTRODUCTION The ea rl y d evelopment of the mid -north of So uth Au stra lia relied heav il y on shipping for t he mo ve m ent of peop le, goo d s an d agricu ltural produ ce. T he strategic locations at Port Pirie a nd Port Augu sta at th e head of Spencer Gu lf provided a ppropri ate port faci lit ies to perm it read y access to north ern far ming and m ining areas . T he develop ment of th ese tow ns a nd the region as a whole wa s, howeve r , dependent on the pro visio n of a suit a ble water supp ly sys tem. Initia lly, wa ter was supplied from ra inwater ta nks a nd by carting fr o m nearby strea ms. Not surp ris in gly these meth od s of supply were qui ckly outgrown. Th e development of a pub lic water supply sys tem for th e northern town s co mm enced in I 865 when th e first pub lic standpipe was in sta ll ed a t Port A ugusta. In 1874, Port Piri e was also pro vid ed wit h a pub lic standpipe. Both sys tem s were initia ll y supp lied from local springs a nd each was later augmented by water fro m sm a ll loca l sur face water storages. A lthou gh Wh yall a was es tabl ished in the ear ly 1900s as the base of the iron ore min ing operations of the BHP Co mpan y at Iron Knob and Iron Monarch, it was not until 191 I t hat a pub lic wa ter supply co nsist in g of tank s fed by a sur face catc hm ent was esta blished. In addition, la rge quant ities o f water we re brou ght to t he to wn as ba llast in ore stea mers . Bores, springs or sma ll dam s were used to provide wa ter fo r ot her loca l wa ter supply schemes in th e no rth ern inland a reas. So me of the loca l schemes are still being operated , hav ing been upgraded a t times to meet current need s. As d eve lo pm ent cont inued a nd the popu lation base ex pand ed , the water supp ly sys tems soon beca me inadequate for th e increas in g needs of th e townships a nd furth ermore th ey

R oberr Th omas is Supervising Investigating Engineer with the Engineering and Water Supply Department, South Australia.

Swan

"'""' V)

WATER TREATMENT FOR NORTHERN TOWNS WATER DISTRIBUTION SYSTEM

Fi .1 So uth A ustra lia , the Stat e Gove rnm ent turn ed its atte ntion to th e development of co mparati ve ly large reservo irs d esigned to supp ly ex tens ive rura l areas a nd associated co mmuniti es through netwo rk s of pipelin es .

2.0 PRESENT WATER SUPPLY SYSTEM The development of the water supply sys tem s has co ntinued to th e present d ay with

the present system se rvin g th e northern a reas of th e State a nd is extensive and complex and provides flex ibility which is necessary to ensure adequate a nd rel ia ble supplies. The major ele ment s of the sys tem are sho wn o n Figure I a nd con sist of: • Water sources and associated trunk mains • Service reservo irs a nd storage ta nk s. • Distribution pipew ork a nd pumpin g sta tio ns • Treatment fa ciliti es WATER September, 1984

27


2.1 WATER SOURCES AND ASSOCIATED TRUNK MAINS The Beetaloo Reservoir (3 700 mL capacity) was constructed between 1885 and 1890 to serve an area extending from Port Pirie to the northern Yorke Peninsula. It was a scheme of considerab le size whi ch estab li shed a precedent for other reg iona l suppl y schemes throughout the State. In 1902 the system was augmented by the co nstru ction of the Bundaleer Reservoir (6 370 mL ca pacit y) and in 1920 the Baroota Reservoir (6 140 mL) was co nstructed providing additiona l water for Port Pirie and other northern areas. The system was then augmented by a sc heme to pipe water from the River Murray to supply t he industria l and domestic needs of Whyalla and to augment existing supplies in other northern areas . This scheme, known as the Morgan-Whyalla pipeline approved in I 940, was completed in I 944. Water is pumped through a 750 mm diameter MSCL pipe for a di stance storage, in a series of four lifts tota lling 475 m. The water t hen · gravitates 266 km to Whyalla via Port Augusta . The majority of th is 358 km main is co nstructed above-ground. The pipel ine also fed into the three northern reservoirs allowing the respective distribution areas to be extended as far so uth as Edithburgh on Yorke Peninsula. In the years that followed, major branches were also constructed to serve Woomera, Iron Knob, Jamestown and Peterborough. After World War II rapid development of the north ern area occurred with decisions by BHP to manufacture steel at Whya ll a, and by the Electricit y Trust of South Austral ia to generate electricity at Port Augusta. To meet these a nd future demands, a second Morga nWhya ll a pipeline of I 050 mm diameter was constructed between I 962 and I 967. Thi s MSCL pipeline was laid alo ngside the original pipeline to near the Baroota reservoir where th e diameter reduced to 825 mm and the pipeline deviated from the origina l route with a 14 km crossin g beneath Spencer Gulf cont inuin g to Whyalla, with a 71 km saving in length . The southern part of the region from the Barossa Va ll ey to the upper Yorke Pen insul a, and port io ns of th e Beetaloo and Bundaleer sc hemes are served by the Warren Trunk Main which derives it s suppl y from th e Warren Reservoir (5 080 mL capacit y) co nstructed in 1916, and the Swan ReachStockwell Pipeline which was commissioned in 1969 to pump water from the River Murray. In this latter system, water is pumped through a 900 mm diameter MSCL pipe for a distance of 35 km from Swan Reach to summit storage tanks at Moculta in a series of three lifts totall ing 406 m a nd then gravit ates some 17 km before the pipeli ne joins the Warran Tru nk Main. T he pipeline then co ntinues for a furt her 130 km before reaching th e open storages a t Upper Paskevi lle whi ch serve as the di str ibution reservoirs to the Yorke Peninsu la.

15 service reservoirs with ca pacities ranging from 0.14 mL to 455 mL. In addition, over 100 storage tanks with capacities of 0.25 mL to 56 mL assist in balancing diurnal variations in demand and maintainin g supplies during breakdowns or maintenance periods.

2.3 DISTRIBUTION PIPEWORK AND PUMPING ST A TIO NS The distribution sys tem served by the Morgan-Whyalla pipe lines and the three northern reservoirs now includ es over 5 500 km of mains, and serves an area exceed ing one million hectares. The Warren Trunk Main feeds a distribution system with about I I 00 km of mains in the lower north, and jointly (with the Morgan-Whyalla sys tem) supplies water to 800 km of mains on Yorke Peninsula , via the Upper Paskevi lle services reservoir. The comb in ed tota l of water distribution main s serving the northern areas of the state now exceeds 7 400 km . Pumping stat ions in th e system a re used to move water from lower to higher storages and booster stations are used when gravity flow is insufficient to meet demand.

2.4 TREATMENT FACILITIES The major treatment facilities currently operated by the Department are the 20 ch lorin ation stations provided to assist in the contro l of the microbiological qualit y. Chlorination was introduced at Morgan in I 959 on an intermittent (weekly) basis for co ntrollin g biological growths in the pipelines. In I 960, a sma ll con tinuous ch lorine dose was used in add itio n to the interm ittent slug doses . Continuous chlorination commenced in 1972). In I 983, the chlorination station at Upper Paskeville at the head of Yorke Peninsula was co nverted to a chlorination facility to evaluate the effectiveness of thi s form of di sinfection in controlling microbiological quality. Preliminary result s have b'een greatly encouraging and it is possible that ch lorination could enventua ll y be used for di sinfection throughout the system. The high level of chlorination of the water suppli es did introduce problems of low pH (down to 5.9 on occasions) and increased corrosion rates in pipelines and fittin gs. To co unt eract this prob lem a pH correction station usi ng caustic soda was co mmissioned in 1974 at Robertstown, the fina l-lift pumping station on the Morga n-Whyalla pipelines, to raise the pH of the water supplied to Port Pirie to at least 7 .0. Following evidence of severe corrosion in the Morga n-Whyalla rising main sections, a new pH correction statio n using hydrated lim e was comm iss ioned at Morgan in 1979 to replace the Robertson faci lity. The Morgan correct ion stat ion now raises the pH of water being pumped from Morgan to a t least 8.0 a nd preferably to 8.5 .

3.0 WATER QUALITY CONSIDERATIONS

2.2 SERVICE RESERVOIRS AND STORAGE TANKS

3.1 General

The supply to the northern region is from the source waters directly, or from one of the

The term water quality embraces those physical, chemica l and bio logical characteris-

28

WATER September, 1984

tics relevant to the use to which the water will be put. Furthermore, the b~ad assessmen t of quality into classifications such as poor or good, depends upon the degree to which these characteristics sati sfy the requirement s of the particular use. For example industrial users quite often place most emp hasis on both the physica l a nd chemica l properties of th e water si nce th ese are important co nsiderat ion s for the co nt rol of corrosion, sca le format ion, pro cess requirements and other sim ilar co nsiderations. The most important quality requirement for a public water supply is its suitab ilit y for human consumpt ion and requires the ·absence of disease producing organisms and toxic substances. Most people now take for granted that water from a public water supp ly system in modern cities will satisfy these public health criteria. It is the aesthetic characteristics of the water wh ich causes greatest pub lic concern since the reticulated water supply for a modern cit y is expected to be clear and odo urless with a pleasing taste. Unfortunately, water supp lies in South Australia have continuous ly fai led in the past to meet modern water quality expectations, and have long been the subject of public criticism. In the northern towns area water quality is highly variable depending on the source, climatic conditions and the time of the year. Figures 2 and 3 illu strate the variation in turbidit y and colour respectively of the northern region water sources. The problems of turbidity, co lour , and taste a nd odour are the resu lt of poor natural catch ment areas and reli ance on the River Murray, which during recent years, has prov ided an average of 79 per cent of the total demand fo r the northern towns . The Morgan-Whya ll a pipelines alone have suppl ied 68 per ce nt of the total demand for these areas during the corresponding period. During the recent drought yea r of 1982/ 83, over 90 per cent of water supplied to the northern towns area came from the Rivtr Murray. The River Murray has a catchm ent of 160 million hectares (approximately one seventh of the area of Austra li a) containin g vast a reas under inten sive agricu lture and horticu ltu re, large urban centres, industrial activit y and extensive recreation areas. The raw water qu ali ty of the River, not surprisin gly, fa il s to meet internationa l drinking water standa rds for colour, turbidity, iron , taste and odour, total di ssolved so lids , and bacterial numbers over significant periods of time. Furthermore, water temperatures in the northern towns distribution system are occassiona ll y very high due to long lengths of above-ground pipelines with temperatures exceedin g 40 °C recorded at Whyalla and Port Augusta.

3.2 Microbiological Quality In an effo rt to ensu re the provision of a relatively safe supply of water to the northern towns, chl orina ti on has been adopted for the control of the bacteriological quality but it is proving increasingly more difficult to continually meet recognised public health goa ls for bacteriological qualit y, due to the extent and complexity of the sys tem, interferences


99 ·9

LEGEND

99

Morgon Pump Stn.

0 9 9 - -- +---+--+- :c l--<f--+-+--H--------1---1

~

98

-.;

>

9 I--- -+---+--+~ -++-1-+-+ - - --+--l

.-.._, 9

"" ""e 8 " .fJ "

Swan Reach Bundoleer

Pump Sin .

Resr.

Beeloloo

Resr.

Boroota

Resr .

Warren

Resr.

--o

~

UJ

70

j° 6 0 ~

:e"

50

i

TABLE 1. TOT AL THM CONCENTRATIONS IN THE MORGAN-WHY ALLA PIPELINES

~ 40

0 30

Location

-=

~

:;;

Organisation . Although g uidelines o n other specific trihalomethanes have not been recommended d ue to the lack of appropri ate data, a World Hea lth Organ isat ion Task Group has concluded that concentrations of tota l THM shou ld be minimi sed. South Aus tra lia n waters, a nd in part icu lar the River Murray, exh ibit relatively high levels of naturally occurring organ ic materia ls with the res ul t t hat ch lorinat ion of t hese waters prod uces high concentrations of trihalomethanes. Furthermore , the formation of trihalomethanes is time-dependent and is acce lera ted by elevated tem perat ures a nd is exacerbated by the long lengths of aboveground pipelines in the northern water supply sys tem. Tri ha lomet hane levels for the Morgan-W hya lla pipelines f.!ee Table l) are con sistently high.

Total THM Concentration (µg / LJ

20

Average (5 y rs)

0

Maximum

.fJ 0

a:

Morga n (before chlorination) (after chlorination) Port Pirie (190 km) Port Augusta (270 km) Whyalla (via No 2 pipe lin e)

0 5 2 l

29 486 688

0 253 311 383

I 122

508

734

3.4 Corrosivity 2 l

5

10

50

100

500

Tu r b i d it y ( N ephe l ometric Uni t s)

REPRODUCED FROM

Water Treatment for Northern Towns Turbidity in Northern Region Water Sources Fig. 2 EWS REPORT ,.WATER TREATME NT FOR NORTHERN TOW NS,. 1978

to d isinfec ti o n ca used by particu late a nd o rganic matter in the water, and reco ntamination of the supply. Prior to 1972, 13 documented cases of the in fect ious di sease prim ary a moebic meningoencep ha litis, or amoebic men ingiti s as it is common ly known, occ urred in the northern towns area o f So ut h Austra li a . O ne case in 1972 strongly li n ked to conta mi nation of the pub lic water supply in Port Augu sta by Naeg leria Jowleri, th e orga nism respon sible fo r th e d isease. In 1972 ch lorination of the water supply fo r m icrob iologica l contro l was introduced at selected locati o ns. T he water su pply was co ntinua ll y disinfected at the var ious sources and boosting of the free ch lorine residua l to greater tha n 0.5 mg/ L was practi ced at Port P iri e, Port A ugusta and Kadi na (where previous cases of amoebic meningitis had occurred). However in ot her parts of the extensive water su pply sys tem , free chlo rin e res idua ls were low or even non-existent. No furt her cases of amoebic meningit is occurred in t he nort hern tow ns area un til the dea th of a chil d in W hya ll a in 198 I. Further di sinfection faci li ties have since

bee n constructed but it is still not possib le to ma inta i n adequate ch lorine re s idual s throughout the entire system. T he pub lic ity which has ge nera ll y surrou nded cases of amoeb ic meni ngit is has contributed to the support for treatment of water supplies to these areas. Disinfect io n strategies for t he co ntrol of Naegleria Jowleri a re d iscussed in an accompanying paper by Robin son and Christy in thi s issue of WATER.

3.3 Trihalomethanes Trihalomet hanes (THM) are chem ical compo un ds whi ch are fo rm ed when chl orine used for disi nfection reacts with organic substances in water. Because of the suspected carci nogenic effects of these compounds, some countr ies have now introduced, or are considering, limits on tota l THM concent ratio ns in dr ink ing water. Typ ica l exa mples are USA (100 l'g/ L, Canada (350 l'g/ L) and West German y (25 l'g/ L). A guid eline va lu e of 30 l'g/ L for chl oroform (one of the THM group) has now been recommended by the World Health

T he high doses of chlori ne used for the disinfect ion of the water supplied to the norther towns introduced t he prob lem of increased co rros ion rates in pi pelin,es a nd fitt ings. Although pH control is practised at Morgan fo llowing initial ch lorination, subsequent chl o rin atio n o nl y serves to aggravate the problem, part icular ly in the more d istant parts of the sys tem. '

4. 0 DEPARTMENT AL INVESTIGATIONS In earl y 1975, the Engin eering and Water Supp ly Department co mmenced an in vestigation to determine the fea sibi lity of improving the q uality of the water supp li ed to the north ern tow ns of the State. T he investigation cons idered a wide range of issues and a variety of trea tment options whi ch cou ld possibly be used wi thin the co mplex water supp ly sys tem. The treatment options included: • domestic water treatmen t • urba n ce ntre water treatme nt • source water treatment The cu lminat ion of the investigation was the preparat ion of a compre hensive report, 'Water Treatment for Northern Towns' and a summary report - both of wh ich were completed in Augu st I 978. T he report concl uded that: 'The qua lity of water suppli ed to the consumers in thi s region of South A ustra lia is genera ll y below accepted world stan dards for dri nking water , the situation be ing aggravated by the abnormally high doses of WATER September, 1984

29


ch lorine requ ired for amoeba control during summer'. a nd furt her: ' . . . with p reva ilin g sta nd ards, art itudes and va lues, water qu a lit y in th e nort hern tow ns area req uires sign ifi cant im provement, but in view of the hi gh cost involved and the present competit ion for fund s, someth in g less than ideal is indi cated ' . The idea l solut io n identified in th e report was based on the source water trea tm ent o ption and requ ired the provi sion of six water filtration plant s together with the roofing and lining of 11 open service storages. Subsequent proposa ls reduce the treatm ent plants to five . The report recommended the ini tial constr uction of two major wa ter filtration plant s : at Morgan (on th e Morgan -W hya ll a pipelines) a nd at Black and White Hill (on the Swan Reach-Stockwell pip e lin es ) wit h capacities of approximat ely 250 mL/da y and 100 mL/ day respective ly . A later proposa l located the latter plant near Stockwell so that , with so me system modificatio ns , water . from bo th th e Ri ver Murray a nd the Warren reservo ir can be treated at th e one plant. By utili sing these two water filtration plant s to the optimum extent, treated water , blended at times with sett led reservo ir water from the northern storages, will be made ava ilab le th roug hou t th e nort hern towns area. Thi s will provide substa ntia l qua lit y im provement whi ch in turn will permit muc h more effective dis in fect ion and amoebae control. It will also provide ba sic fa cilities wh ich can be augmented in future to give further water quality im provement, with th e longter m obj ecti ve of ac hie vin g Wor ld Hea lth Organisa ti o n gu id elin e va lues in the whole ystem .

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5.0 WATER FILTRATION TO IMPROVE WATER QUALITY With the progress ive deterioration in the qua lit y of water in th e Ri ver Murray, the suppl y to the Nort hern Town s co ntinu es to be ad versely affected . On February 2nd 1981, State Cabinet approva l was gi ven to p roceed with the developmen t of co nceptua l and detailed designs, specifications a nd ten d er document s for two water filtration p la nts , on the Morgan-Wh yalla and Swa n Reac hStockwell pipelines, at an estimated cost of $3 mi lli on. The proposed Plants wi ll adopt treatment processes similar in broad concept to those being used at a ll ex istin g plants in the Ade laide Metropolitan Water Filt ra tion Scheme . The safe wa ter will be produced by th e removal of micro-organi sms to acceptab le leve ls, and an aest het icall y pleasing and pa latab le water , by the remova l of turb idit y, colour, iron , taste and odour. The control of Naegleria fow leri will be imp roved by more effect ive d isinfect io n . However , the lim iting o f triha lo meth a ne production d own to low levels is not poss ible with the e fac iliti es although judicious operat ion will enab le some reduct ion on present leve ls in unfiltered supplies. The ac hieve ment of a signifi ca nt reduction o f triha lomethanes wo uld requ ire eith er th e introduction of chlora min at ion for disinfection o r add iti o nal treatment techniques which

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in some cases are still being de veloped. This iss ue is being in vesti gated closely by the E ngineer ing and Water Supply Department. Firm recommendations o n th e contro l of trihalomethanes in t hi s a nd other system s cannot rea list icall y be present ed to Govern ment until the present investi gation into the occ urrence , formation and contro l of these compounds is comp leted , and objective levels are estab lished for So uth Au stra li a n water supplies.

6.0 MORGAN WATER FILTRATION PLANT T he Morgan Water Fi ltration plant will supply filtered water to th e major indu strial tow ns o f Port Piri e, Port Augusta a nd Wh ya ll a a nd adjacen t mid -north area s a nd will supplement th e suppl y to the Yorke Peninsula. Some 90 000 consumers will benefit. In Jun e 1981 , the co nsulting firm of Camp Scott Fu rph y Ptd. Ltd. was engaged to carry o ut th e concep tua l a nd detailed des ign fo r the Morgan Water Fi ltra ti o n P la nt , the co nceptual d esign report was present ed in March

1982, and detai led design and documentation is now comp leted. Th e ma in s tru ct ures a nd buildings of the pla nt will be co nstructed adjacent to the two ex isting Morgan Pumping Stat io ns (referred to a s No I a nd o IA) on Crown Land. Although the hydrauli c capacit y of the p ipelines su pp lyin g water to the summit storage tank s at H anson is 250 mL/ da y the exi stin g pumping sta ti o ns a t Morgan have a capacit y of just over 200 m L/day. Pumping capac it y ca n be increased by augmenti ng the pumping fa cilities a lo ng the Morgan -Whyalla ri sing main s. T he proposed Morga n Water Filtration Plant has been designed wit h a process capac it y of 200 mL / day a nd a hydrauli c capacit y of 250 mL/ d ay to enab le the plant to be upgraded to treat a flow of 250 mL/day mat ching the hydraulic capacit y of the pipeline. It is not expected that augmentat ion of the sy tern will be requ ired before the yea r 2005. River Murray wa ter wi ll be drawn thro ugh th e screen structure a t the ex isting No I A pumping stat io n a t Morgan a nd pumped to


th e filtr a ti o n pl a nt by three new va ri a bl e speed pumpin g unit s whi ch will be loca ted in sid e th e Nci I A Pumpin g St a ti on. Alum for prim a ry coagul at io n will be a·dd ed to th e water in a 2-stage ra pid mix ta nk in corpo rating mecha ni cal mi xe rs fo r chemi ca l di spersal. Th e coag ula ted wa ter will th en be con veyed eith er to th e fl occ ul a ti o n a nd sedim ent a ti o n ta nk s fo r th e no rm a l mod e o f opera tion , or directl y to the filt ers fo r a direc t fi ltra t ion mo de of o pera ti o n when wat er qu a lit y in th e Ri ver Mu r ray is suit a bl e with co nsequ ent reduction in o pera tin g co sts. Th e 3-stage flo ccul a tion tank s pro vide gentle stirrin g with mec ha nica l mixers of th e verti ca l turbin e type to aggrega te th e fin e pa n ciles and so produce a se tt leabl e flo e. Th e mi xe rs will be provid ed with speed ad justment (to pro duce a G va lu e betwee n IO a nd 80) to ensure th a t co mplete co nd iti o ning o f th e wat er ca n be achi eved under va riou s wa ter qua lit y fl ow co nditi o ns. T wo ho ri zo nta l fl o w sedim ent at io n ta nk s ra ted a t 3 m/ hr and 1. 3 hours d ete ntion will rem ove th ~ maj·orit y o f th e so lid im puriti es . Eight sa nd / a nth rac ite filt ers rated a t 14 .5 m/ hr a nd utili sin g filt ered water flo w co ntro l will remo ve th e rema ining fin e flo e particl es p rodu cin g a high qu a lit y filt ered wa ter. Aft er chl o rin a ti o n , th e filt ered wa ter will fl o w to a 12 ml circ ular con crete tank from whi ch it will be draw n by the hi gh lift pumps in No I a n No I A pum p ing sta ti o ns fo r di sc ha rge to th e Morga n-Wh ya ll a pipelin es a nd th ence into th e di stributi o n system. Oth er chemica ls used will be qui c klime fo r pH adjustement a nd corros ion control , acti vated silica to ass ist coagu lat ion and flo ccu la ti o n , po lye lec tro lytes to ass ist coa gulatio n a nd fl occula ti o n o r filtra ti o n , a nd hydrofluosilicli c acid a s th e fluoride source to ass ist in the impro ve ment o f dental hea lth. Space will be prov ided fo r th e possibl e d os ing 0f acti va ted car bon (for taste a nd od o ur con trol), chlor ine dio xide (as an a lt ern a tive di sinfectant or fo r organi cs oxid a ti o n to assist in th e control of trih a lom eth a nes) , and aqu eous a mmoni a for chlo ra minati o n whi ch ha s th e p o te nti a l t o grea tl y im prove mi cro bi o logica l qu a lit y co ntro l throu gho ut the wa ter suppl y sys tem a nd to a lso a ssist in th e contro l of tri hal o methan es. Air ass isted bac kwas h will be used a nd was h wa ter will be recycl ed to the wor ks inl et at a contro ll ed rate as a wa ter con serva tion meas ure . Sludge fr o m th e sediment a ti o n ta nk s will be removed by automati c travellin g bridge sludge coll ecto rs a nd di sc harged to a slud ge thi ckener inco rpo ra tin g a pi c ket-fence thi ckener mec ha ni sm . Th e thi ckened sludge will th en be pumped to the two hecta res o f slud ge dryin g beds where a ir dryin g will be prac ti sed in th e idea l clima tic co nditi o ns which preva il at Morgan. Th e dried slud ge will be removed from the beds a nd tra nsport ed to a suitab le land -fill sit e. Annu a l average da il y sludge p roducti o n will be a bo ut 8.5 to nn es of dry so li ds but a t tim es of hi gh turbidit y (exceedin g 400 NT U) da il y pea k sludge produ cti o n could be in excess o f 60 to nn es of dry so lid s. T o ca ter for thi s wid e va ria tion a nd varia t ion s in clim a ti c conditi o ns, 12 000 m 3 of sludge sto rage will be pro vided in a ddition to th e dryin g beds .

A ll c hemi cal storage, ha ndlin g a nd dosing fac ili ties will be loca ted in or nea r th e c he mi ca l build ing . :rh e a dmini str a ti o n buildin g will ho use the ma in co nt ro l roo m a nd asoc iated eq uipm en t incl uding a Kent K90-S/ P4000 co mpu te r based Da ta Acqui siti o n and Co nt ro l Sys tem , th e labo ra to ry, o ffi ce acco mm oda ti o n a nd staff a nd empl oyee a menities . A ma int ena nce buildin g will hou se fac iliti es fo r th e m ec h a ni ca l/ e lec tri ca l/ in strum ent at io n ma int ena nce of th e water filtra ti o n p la nt a nd the 11 ex ist ing pumpin g stat io ns a lo ng the Mo rga n-Wh ya ll a a nd Swa n Reac h-Stoc kwell pi pelin es , toge th er with stores, firs t a id r oo m a nd empl oyee a meniti es. In th e pla nnin g a nd des ign, enviro nm ent a l and aest heti c co nsid erati o n ha ve bee n o bserved a nd la ndscaping a nd p la ntin g p rovided fo r. Th e fo ur pai rs o f Mo rga n-Wh yall a Pum ping Stat io ns will con tinu e to o perate durin g off-pea k elec tri ci ty ta riff per iods to minimise cos ts . Th e Mo rga n Filt ra ti o n P la nt will o perat e accordin gly durin g th e off- pea k periods . W a ter p roduct io n wi ll no rmally occur between 8. 15 p .111 . a nd 7 .30 a .m . durin g wee k d ays a nd 24 ho urs per day a t wee kend s. Th e tota l est im a ted costs of th e p la nt in cludin g a ll a ncill ary costs a nd ho usin g for ' key' em ployees, is $3 1.2 milli o n (a t Jul y 1984 va lues). Th e Comm o nwea lth Go vern ment will co nt rib ute to th e ca p ita l cos t by way of gra nts un der th e Na tional Wat er Resources Progra mm e . Th e tot a l annu a l cha rges including debt recharge a re est im ated to be $6 .85 milli o n (a t Jul y 1984 values) . Bas ed o n a n es tim a ted a nnu a l thr o ughput in 1987 o f 38 300 ml , the to ta l a nnu a l cha rges represe nt a unit cost o f 17.9 cent s pe r kil o litre . C onstru ction of th e M o rgan Plant com menced in Febru a ry 1983 when a co nt rac t was let to A. W . Ba ulderstone Pt y. Ltd. fo r th e co nstru ction o f th e filt ered wa ter ta nk. Sin ce th a t tim e, ma jo r co ntracts have been let to A. W . Ba uldersto ne (fi rs t Civil Co ntract) , a nd F . R . May fi eld Pty. Ltd . a nd Kent In strument s (Au st.) Pty . Ltd . - Mecha nica l a nd Elect ri ca l Co ntract a nd Nomin a ted SubCo nt ract fo r Instrum en tat io n a nd Contro l Equipm ent res pec ti ve ly. Th e slud ge ho lding lagoo ns a nd dr yin g beds a re being con structed by Depa rt menta l d ay- la bo ur. Se pa rat e contracts for th e Buildings , a nd Road work s a nd Drainage will be let in due course. Th e a nti cipat ed commiss io nin g d a te for th e Mo rga n Plant is la te 198 6 - provid ed th a t adequ a te leve ls of fundin g continu e to be made avai lab le by bo th th e Commonweal th a nd Stat e G overnm ent s.

7 .0 STOCKWELL WATER FILTRATION PLANT The proposed Stoc kwe ll wa ter filtrati o n pla nt wil l supply filt ered wat er to th e Barossa Va ll ey, th e Mid -No rth a nd Yo rk e P eninsul a. Th e plant will se rve a po pul at ion of 30 000 plus co untry land use . It will be th e second of th e two pl a nt s to be des igned foll o win g approva l by Ca bin et in Febru a ry 198 1. After a de ta iled sit e in ves ti gati o n by th e Depa rtm ent th e pla nt will be constructed near Stoc kwell , upstrea m of th e juncti o n with the Wa rren Trunk Ma in, at a n es tima ted cos t o f

$ 13 .5 m illi o n for the water filtr a ti o n pla nt a nd $4.3 milli o n fo r associa ted wo rk s in volvin g th e di version o f th e Wa rre n Trunk ma in (Jul y 1984 values). Thi s sc heme will provide filt ered water to th e Yo rk e Penin sul a a nd m ost o f th e Ba rossa Va lley a t a ll times, wheth er th e so urce o f wat er be th e Swa n Reac h-Stoc kwe ll pipelin e o r Wa rren rese rvoir. Th e adopt ed sit e is pre ferrabl e to th e o rigin a l cho ice of Bl ac k a nd Whit e H a ll beca use it obv iates the need to co nst ru ct a furth er pl a nt in th e futur e to trea t Wa rren reservoir wa ter. Th e co nsultin g fi rm o f M o nt gomeryHos king P ty . Ltd. was engaged in November 1982 to deve lo p th e con cept.ua l d esign for Stoc kwell wa ter filtra ti o n pla nt a nd thi s wor k has now bee n co mpl eted . Deta il ed design a nd con struction of th e plant will be subject to the avai la bi lit y o f fund s in future years. Th e pl a nt will have a p rocess des ign capac ity of 100 ml/ day (w ith a n ultim a te ca pacit y o f 150 m l/d ay), and will compri se : • a single-stage ra pid mi x ta nk in co rpo rat ing a pum p bl ende r for chem ica l di spersion . • 2-s tage flo cc ulati o n ta nk s with mec ha ni ca l mixers o f th e ve rti cal turbin e type, with adj usta bl e speed ra nge to produ ce a G va lue betwee n 5 and 60. • two hori zo nt a l fl ow sedim enta ti o n ta nk s ra ted a t 2 m/ hr a nd 1. 5 ho urs detenti o n , complete with tra ve llin g bridge sludge col lectors. • fo ur Ha rdinge (travellin g bridge type) filt ers rated a t 7 .5 m/ hr with o ne off lin e . • a 20 ml fi ltered wat er storage tank. • 1.6 hecta res o f sludge dr ying lagoo ns fo r a ir d rying th e es tim a ted a nnu a l average d a ily slud ge produ cti o n a mo un ting to 2 .3 to nn es o f dr y solids. Fina l s'iudge disposa l after drying will be by la nd -fill. Th e Stockwell plant will use th e same process chemi ca ls (both initial a nd p ossibl e future) as th e Morga n,.pla nt , with th e excepti o n o f hyd ra ted lim e in li eu of qui cklim e. In additi o n, faciliti es will be pro vid ed for dos in g cau stic sod a fo r post-filtr a ti o n pH a dju stment , po lymer fo r slud ge co nditi o ning, a nd future dosin g with a corrosion inhibito r. Th e plant is on a hi ll top in a rura l community and pa rticular att ention has been give n th e en vironm enta l a nd architectura l aspects. The H a rdin ge filt ers a re a most int erestin g fea ture. A ut o ma ti c bac kwas h is e ffec ted by a bac kwas h hood ca rri ed o n a trave lling bridge a nd co vering eac h ce ll in turn a nd bac kwashing while the rema inder of th e filt er continu es in se rvice . Th e filt er med ia is sha ll ow (400 mm , sand) with res ultin g low head loss a nd requiring a filt er box of o nl y 2.5 m co mpared with 5 111 fo r a co nve nti o na l du a l medi a filt er . Th e a pproach is we ll suit ed to th e St oc kwell sit e o fferin g cos t sav in gs, re liabilit y a nd th e o pti o n of unm a nned o pera ti o n. Th e Co nsult a nt has recomm end ed a co mput er based co ntrol system with telem et ry to permit remo te mo nit o ring wh en the pl a nt is un a tt ended. Anti cipa ted staffi ng will be fo r eight ho urs per d ay req uirin g five full time a nd fi ve pa rt tim e perso nn el. For compa riso n , a three shift 24 ho ur/ d ay p lant wo uld requi re 16 perso nn el. WATER September, /984

31


The es tim ated constructi on cost of th e pl ant and associated wa ter suppl y system modificati on is $ 17.8 mili on and total annual charges including debt recharge· are estim ated to be $3 .7 million, at July 1984 va lues. Based on an est ima ted annual th roughput of 18 250 ml , the tota l annual charges represent a unit cost of 20.5 cents per kilolitre.

8.0 SUMMARY Despite the limited nat ure of th e water resources in South A ustra lia, th e State's residents have, by and large, enjoyed very reliable and unrest ri cted publi c water suppl ies. H owever , many of th ese maj or sources do not sa ti sfy recognised water qualit y obj ectives for municipal suppli es. Th e South A ustra lian Government has now embarked on a major wo rks programme for the treatmen t of the water supplies fo r the nort hern tow ns of the State . Constru cti on of the M organ wa ter fil trati on plant has now co mmenced and is scheduled to be co mpleted in late 1986 . Conce ptual design for the Stockwell water filt rat ion plant has been co mpleted, but detailed design and constru cti on will be subj ect to th e availabi li ty o f fund s in future yea rs. Because of the co mplexity of the north ern water supply system, the Morgan and Stockwell water filtration plants alone wi ll not prov ide th e panacea for all the wa ter qualit y ills of th e supply. Th ey will however represent a signi fica nt advance ment towards achieving accep table standards of public wa ter supply qualit y for the north ern towns of South A ustralia.

9.0 ACK NOWLEDG EMEN TS Th e developm ent and implement ation of pro posals by th e Engineering and Water Suppl y Departm ent fo r the treatm ent of the water supplies for the nort hern towns of South A ustra lia has invo lved th e effort s of many peopl e over several years . Thi s paper is published with th e permi ssion of th e Director General and Engineer in Chief , of the Engineerin g and Water Suppl y Departm ent , South A ust ralia.

AWWA-IE AUST. NATIONAL SEMINAR Adelaide-Nov. 22-23 'The Changing Management Needs of the Australian Water Supply and Sewerage Industry'. For details see Page 9 Branch News.

S. Au st .

Information and Registration - IE Aust., 11 Bagot St., Nth . Adelaide 5006.

32

WAT ER September, 1984

TECHNICAL INTERESTS GEOLOGICAL ENGINEERING AMIT Melbourne Th e Royal Melbourn e In stitu te of Tec hn o logy o ff ers th e only Geologi cal Engin ee ring Deg ree Course in Au s tralia. Th e four year co urse c ov ers a wid e range of topi c s from t he use of earth material s to tunn elling and mining operations and recovery of water and petro leum produ c t s from underground . Information from Mr. Jim Robinson, Dept. of Applied Geology, RMIT, GPO Box 2476V, Melbourne 3001 .

DRILL '84 SYMPOSIUM HIGH TECHNOLOGY IN DRILLING AND EXPLORATION Canberra, Oct. 7-11 Sympos ium and Exhibition of th e Nati o nal Waterw ell and Drilling Assoc iation of Au s trali a o ffers a se ri es of seminars and papers o n drillin g for new energ y sources, large diameter dril li ng and the use of co mputers in c ontract adm ini stration and drilling operations. Information from John Mills, PO Box 187, St. Ives 2075 (02 449 3382).

SYMPOSIUM

FRESHWATER ECOTOXICOLOGY IN AUSTRALIA

Water Research Foundation SEMINAR

Chisholm Institute of Technology - Nov. 27, 28

DRAINAGE SYSTEM PROBLEMS

Di sc ussio n will inc lu de a revi ew o f pas t and prese nt fres hwate r ec otoxico logi cal tes ting , th e use of data in d eveloping c rit eri a and a c riti cal look at present progamm es. Key note Speaker is Or. Don Mount , US EPA, oth er speakers are fro m USA and interstate. Information: Mr. Tom Davies , Water Studies Centre, Chisholm Inst. of Tech. , Caulfield East, 3145 (03 573 2168).

Sydney, Nov. 28

HYDRAULIC RESEARCH INT. CONGRESS Melbourne, Aug. 19-23, '85 Thi s 21st Congress is th e bi ennia l mee ting o f th e International Association for Hydraulic Research is spons ored by th e In st. Engin ee rs (Au st). Venu e is th e Univers it y of Melbourne. Th emes w ill in c lud e: • Subsurfac e flow , pollutant transport and sa linity . • Free surface hyd ra uli cs and wat er managem ent. • Fl ows and sedim ent s in Harbours and Inlet s. • Flow measurem ent s and data ac quisition. Parall el event s will be th e ' Flom ek' Conference on fl ow meas urement and a semin ar pro gramm e o n urban hydrauli cs, desi gn of hydrauli c stru c tures, hydrauli c tran sient s, sma ll hydro pow er generat ion . Information: Int. of Eng. (Aust), 11 National Circuit , Barton , ACT 2600.

The Foundati on will co nduct a one-day seminar on ' Problems of Existin g Storm water Dra inage Sys tems' at the Fl ying Angel House, 11 Macquari e Pl ace co mmencing 8.30 a. m . Details: Secretary WRFA , PO Box 123, ' Broadway, NSW 2007.

HAZARDOUS WASTES and DIFFICULT EFFLUENTS April 14-27, 1985 Thi s course, organi sed by th e British Council in co-operation with the Universit y of Newcastle upon Tyne wil l revi ew th e lat est d eve lo pment s in assess in g, contro ll ing , treating and di s pos in g o f haza rd o us wast es and diffi c ult in d ustrial efflu ent s. Topi c s w ill in c lud e: c lassifi cation , regulation and control ; incin eration , stabili za ti o n , landfill and leac hate ; radioa c ti ve , ph a rm ace utical , pe tro c hemi ca l, te xtil e and plating was t e manag ement . Venu e is th e Univers it y, Newcas tl e upo n Tyne, course will in c lude several site visit s. Information: The British Council, PO Box 88, Edgecliffe, NSW 2027.

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Water Journal September 1984  

Water Journal September 1984