Territory Stories

East Alligator district centre water supply assessment : Kakadu National Park



East Alligator district centre water supply assessment : Kakadu National Park

Other title

D . Pidsley


Jamieson, M.; Pidsley, D.; Paiva, Jerome


E-Publications; E-Books; PublicationNT; Technical Report ; 26/1991




Made available via the Publications (Legal Deposit) Act 2004 (NT).






Water-supply -- Northern Territory -- Kakadu National Park; Groundwater -- Northern Territory -- Kakadu National Park; Kakadu National Park (N.T.)

Publisher name

Power and Water Authority

Place of publication



Technical Report ; 26/1991


1 v. : ill., maps ; 30 cm.

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Check within Publication or with content Publisher.

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Technical Report WRD91026 Viewed at 15:07:48 on 29/07/2010 Page 99 of 107. ., . ! , .~ " 1 t $,nQm_nnq Can~Nf1t:. O.twtn MIIV 11 ns. 1987 Extreme Corrosivity of Northern Territory Coastal Groundwater !iupplies - Origin, Effects and Materials of Construction A.R. MARKS Chief Engineer PubHc Works. Nonn.rn fetritory OelJal1ment ot TranSQOrt and Works P. JOLl.Y Pnncl~.,t S'nglnut$ Assessment Branch. Ware" Resourees Division, Nor..hem TerritOry Oepartm"nt of Mines and Enel'9Y The coastal st...-ip of Northern Territory,. Aust..."'3.lia,. has sort acidic grcund;.{acars '.whidl .are highly ..,.u;cYcsiVllt to ~per, brass, mill:} steel, galvanized. iron, asbestos cerent. and ctm!nt lined pipes and fittir.gs, and other hydr3Ulic catQOnents~ '!he cause of the corrcsivit'! is acidity" aris~ fraa. dissolved CO, believed to originate fran the high CO2 respiration rate of tree and plant roots i.n ttl!! aquifer ':'eC1arQe areas dlrirq th.e 'Net season.. 1he lntrodu~ion of cort"05icn resistant materials of constr.lCtion is mt1.ined as tt'l.e preferred cption to ..,.rater t....~at::rent ... Al.zros:t all camunities in the ,S(,rt..'1ern Territorl rely on qrcundwater in t.!oJ.e ema of oores or permanent sprin:,;s .JS their pri.'"tIar'l sc:urce of supply.. '!he ext:e9tions are ll!I.rwin,. lat."lerine" .tcd /Igtll<urr (llq>e.- Ri"".-) whim have surface catC'men.t supplies 1-n.th minor supple:rentation fran bores. '!he 1.lndI!!rgra.md watf';r rua.:=o;3 C t.'1e Territor,! V'Ar/ qreatly in quality,. gene-rally havin; lew to ;nary lew JUine:cal.iution in the m::msconal areas to the north wit..'1 increa.sirq min&l':'alization in the temperate an:! desert: inland ra;ri".,.. to the 5O..l t.'>. '* ~ .. '!'() .AWe! "SPRi.';S -AU. ~1-6( ...... ( !M.<;Ur'O 1 !i>rthern Territor{ ",,,,,,tal toms -.i t:I\ hiQ1l.y c:orrmive ll%K2:tgram<i vatElr scw:ces Corrcsivity of the waters is 'J."lriable tut al~ the coastal ,/i:OJ..n.d'...ater a.:pp1ics are highly cocrcsive.. 1'WenJ:t/ one .:rain "'-""A!Stal camunities and nurrerOJ.$ small Oltscaticns ~.....sin;;: a pc:pulacion of .".aM J.2,OOO (9t of the Territor!) are involved as shewn in Figure 1. Suoolies to Alyarq.t.!.a ar.d Angur~ are dt-emical.ly t~-3.t.ed to rOCuce the corrosive ci1aract'.er::'<:I.ticsf' and aerat:ion orovides D3rti3l treabre~!C at ~tu .. J.Uf'b:'y" Afl of t.."":e ota'1er suppli;"""s are rel:l.cul.at..o:d witi'lCtlt. condit.icning" treattwtnt.-5 In 1983 t followinq incidents of high -water -use and ="'" of plumbing cor:oding cut 50 r.:;pidly that hOlSes cculd not be nei...,tained in an habit:.able condition, the Cep.act:tent of Trarb';'Ort. and 1Io~ engaged '!he Nstr31.ian Mineral Oavelccment Laboratories (}Ol1DEt.l of Oleens.1a.nd to invest.igate t.."le problem. !he consultant o::!ncluded thz:...: failures were cccurrin; on a :rassL.'e scale to an extent: un.knc:Mn e iser.omere in Aust.'"Ollla.. and that the high failure rate of ccpper pipe # brass fittings arxi hot water systsrs resu..i.ted f::'OIl. the high corrcsillity of the soft, acidic bore ...raters (AMIEr.., 1984) .. In addi~ion to house plumbing i~ has been otse!:Ved that: galvanized iron and as.best:C6 cement retiOJ..lation :naif'S, brass tapping fer:ules and asscciated. fittings,. galvanized iron t.anks, mild steel bore casin;; and co.il..:mns, and. ~ CO"I'{:Onents are attac~ed. Corrcsivicy ~ a 'Mater may be defi.~oo all the ?Jtential or ability of :.. .... ac water to dissolVtt mat~rials of ccn5t..."'"tlction.. Ccrrcsicn is a physic:::l....,...:..erucal act.ien rela.ted to the characteristics of the A'ater and mat.erial of const.:"..lction. Wat.ers beo::r.e ;rore disro.i.ved oxy.;en, _ol .. ::Slve .. It..>-::. dis-sol'led car.bOn increasin; dioxide,