Water Journal March - April 1999

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Volume 26 No 2 March/April 1999 Journal Australian Water & Wastewater Association Editorial Board F R Bishop, Chairman B N Anderson, D Deere, P Draayers, W J…
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Volume 26 No 2 March/April 1999 Journal Australian Water & Wastewater Association Editorial Board F R Bishop, Chairman B N Anderson, D Deere, P Draayers, W J Dulfer, G A Holder, M Muntisov, P Nadebaum, J D Parker, M Pascoe, AJ Priestley, ] Rissman, F Roddick, E A Swinton·, Water is a refereed journal. This symbol indicates that a paper has been refereed.General Editor Margaret Metz, email: nunetz@awwa.asn.au AWWA Federal Office (see JXlStal address below)Features Editor EA (Bob) Swinton 4 Pleasant View Cres, Wheelers Hill Vic 3150 Tel/ Fax (03) 9560 4752 Email: swintonb@c031 .aone.net.auBranch Correspondents ACT - Ian Bergman T el (02) 6230 1039 Fax (02) 6230 6265 N ew South Wales - Leonie H uxedurp Tel (02) 9895 5927 Fax (02) 9895 5967 N orthern Territory - Mike Lawton Tel (08) 8924 64 11 Fax (08) 8924 6410 Queensland - Tom Belgrove Tel (07) 3810 7967 Fax (07) 3810 7964 South Australia - Angela Colliver Tel (08) 8227 1111 fax (08) 8227 1100 Tasmania - E d Kleywegt Tel (03) 6238 2841 Fax (03 6) 234 7109 Victoria - Mike M untisov T el (03) 9278 2200 Fax (03) 9600 1300 Western Australia- Jane Oliver Tel (08) 9380 7454 Fax (08) 93881908Advertising & Administration AWW A Federal Office PO Box 388, Artarmon N SW 1570 Level 2, 44 Hampden R oad, Artarmon T el (02) 94131288 Fax (02) 94131047 Email: info@awwa.asn.au Advertising: Angela Makris Graphic Design: Marion Kennedyt;"Water (ISSN 0310 • 0367)is published six times per year: January, March , May, July, September, November byAustralian Water & Wastewater Association Inc ARBN 054 253 066!UP\idCONTENTS From the Federal President ... .... ........... ........ ........................ .. ..... .................. 2 From the Executive Director ............... ................................. .. ... .......... .... ....... 4 MYPOINTOFVIEWMaking the Intangible Tangible ....... .. ... .. .... ................ ....... .. ........... ...... ......... 3. A Makris WATER Water Solutions .............. ................................................ .................... ............. 7 C Allen ·, Identifying Cryptosporidium Using DNA Methods ... ....... ... .. ... ...... ..... .-.... 9 U Morgan, R C A Thompson ·, Water Treatment Options for Cryptosporidium and Giardia ........... ... .. 11 B Murray, K Linneman n, K Craig [ ·, Bioavailability of Aluminium In Alum-treated Drinking Water and Food ............... ............................ ................. .... ............ .. ... .......... ..... ......... 17 J L Stauber, CM D avies, MS Adams, S J Buchanan, TM Florence Asia Water Comes to Sydney ... ... ..................... ...................... ...... .... ..... ....... 23 C D avis WASTEWATER ~ Groundwater Contamination from Effluent Irrigation ... .. ............. ........ 26 VO Snow, P J D illon, W J Bond, CJ Smith, B J Myers Sustainability and 'SNABWEMs' .... .............. ... ............. ...... ...................... .... 31 M Laginestra ENVIRONMENT......Federal President Greg CawstonExecutive Director C hris D avis Australian Water & Wastewater Association (AWW A) assumes no responsibility for opinions or statements of facts expressed by contributors or advertisers. Editorials do not necessarily represent o ffi cial AWWA policy. Advertisements are included as an information service co readers and are reviewed before publication to ensure relevance to the water environment and objectives of AWWA. All material in Water is copyright and should not be reproduced wholly or in part without the written pennission of the General Editor.Subscriptions Water is sent to all members of AWWA as one of the privileges of membership. Non-members can obtain W,1ter on subscription at an· annual subscription rate of S50 (surface mail).Ozone Water Treatment Used to Save Rare Queensland Frog ... ... . ... ... .. . .. 33 P Barlow [ ·f Protecting Inland Waterways: Environmental Management at Lower Molonglo .................... ...................................................... ........ .......... .. 35 R H ogg, A Wade, A Wijeratne BUSINESS "·, Water Markets: Buyer and Seller Perceptions ......................... ..... ........ 41 H Bjornlund , J McKay DEPARTMENTS International Affiliates ...... ..... ............................................................. .......... 5 From the Bottom of the Well ........ ....... .... ...... .... .. ............................... ........... 4 Meetings ... ........... .......... ... .. ... ...... ..... ... .............. .. .... ....... .. .. .. ..... .... ......... ... .... 49 Books ................. ............. ............ ... .......... ... ...................... ... ... ......... .... ...... . 8, 30 OUR COVER: Fleayi's Barred Frog (Mixophyes fleay1) is in danger of becoming extinct and the water industry is doing its b est to ensure the survival of this rare Australian species. In cooperation with Lone Pine Koala Sanctuary, Sea World and th e Queensland D epartment of Environment and H eritage, Ionics Watertec has designed a water filtration and ozo nation system that removes pathogens and reproduces th e pristine water quality of the frog's rainforest stream habitat as an essential part of a captive breeding program to be undertaken over the next five years. Photo courtesy of Eric Vanderduys of the Queensland Museum and IonicsW atertec. WATER MARCH/ APR IL 19991~WATERU Morgan, RCA Thompsoncollected over 400 different isolates of Cryptosporidit1m is an intestinal Cryptosporidit1m, of which approxiparasite found in humans and animals. mately 300 have been characterised It m ultiplies within the surface layers genetically or 'genotyped.' of the host's small intestine, causing At present, at least seven genotypes damage w hich may lead to severe of C. parvum have been identified: a diarrhoea. When this ti ny (5 Âľm) 'human' genotype which has so far single- celled protozoan parasite leaves been fo und only in humans; a 'cattle' its host, a tough outer shell favours its genotype found in domestic livestock survival during routine water an d such as cattle, sheep , goats etc. and wastewater di sinfectio n and treatwhich can also infect humans; a ment. 'mouse' genotype that has been found Cryptosporidit1m has co me to in mice from around the world and prominence in Australia as a result of more recently 111 bats; a pig Cryptosporld/um and Giard/a In the small the recent contamination of Sydney genotype; a 'marsupial' genotype th at water supplies, but came to world Intestine has been found in koalas and kangapro m inence in 1993 whe n over both genetically and biologically. It is roos; a 'dog' genotype; and a 'ferret' 400,000 people in Milwaukee, USA possible that these strains will be classed genotype. became infected with it as a result of as new species in the near future. So fa r only the 'human' and 'cattle' drinking contaminated drinking water. Currently, our research in the genotypes have been found in healthy Amongst AIDS patients who contracted Division of Veterinary and Biomedical human beings, and the public health cryp tospo ridiosis as a result of th is Scienc es at Murdoch University significance of the remaining genotypes outbreak, the outcome of disease was involves cha racterising the is unknown (see Figure 1). Since most severe, w ith 52% to 68% of people Ciyptosporidium fou nd in a variery of of these ' new' genotypes appear to be dying within six months to a year after hosts using sensitive DNA-based detec- host-specific, they are unlikely to infect the outbreak. Since t his epidemic, tion methods. As part of our role as a people with intact immune systems. It Cryptosporidit1m has been the subject World Heal th Organisation is possible, however, that individuals of an enormous amount of research Collaborating Centre for the Molecular with deficient immune systems such as wo rldwide and has the unusua l Epidemiology of Parasitic Infections, AIDS patients may be su sceatible to distinction of having its own we have been collaborating w ith a wide other Clyptosporidiwn genotypes. magazine, C1yptosporidit1m Capsule variery of National and International Current methods for identifying (http://www.fspubl.com). R esearc h Ce ntres, including the Cryptosporidium in water supplies Despite the vast amount of research Centres for Disease Control (CDC) in generally rely on immunofluorescent that has been conducted, there is still a Atlanta, USA, and we have now microscopy and/or flow cytometry, in great deal that we do not know about which fluorescent antibodies bind Ciyptosporidium. At present up to to Cryptosporidium and diagnosis eight species have been recognised: is made on the basis of morphologC. muris which infects mostly ical characteristics. H owever, rodents but also cattle and other because all the genotypes of C. hosts; C. wrairi w hi ch infects parvum are morphologically identiguinea pigs; C. meleagridis and cal, they cannot be differentiated C. baileyi in birds; C. serpentis in using these techniques. This can reptiles; C. nasornm in fish; C. [elis be done using DNA- based only in cats and C. parvum in humans techniques. and other mammals. If we can determine the Cryptosporidium parvum is the genotype of Cryptosporidium most widely stud ied species. In the found in water supplies, this will last couple of years it has become not only tell u s if parasites that are increasingly clear that C. pa1-vt1m is potentially infectious to humans not a single species but is are present, bu t it will give us Purified Cryptosporidlum oocysts (arrow shows composed of a number of distinct information about their source. single oocyst) 'strains' (or genorypes) th at differ WATER MARCH/APRIL 19999WATERTransmission of major Cryptosporidium genotypes C. parvumFigure 1 Transmission dynamics of CryptosporidiumFor example, if the 'human' genotype is detected, it must have come from human faecal co ntamination of the water; if it's the 'marsupial' genotype, it may have come from marsupials in the catchment area; and so on. R esearch to date on a number of waterborne outbreaks in the UK and USA , including the famous Milwaukee outbreak , has indicated that most waterborne outbreaks have been caused by the ' human' genotype. Future genetic and biological characterisation studies are required on a wider range of isolates in order to confirm the distribution of these genotypes and to determine if they are in fact separate species. Ongoing human-infectivity trials in the USA will also provide important information as to the public health significance of the 'mouse', 'pig', 'marsupial' 'ferret', and 'dog' genotypes. Authors Dr Una Morgan is a molecular biologist and Professor R C Andrew Thompson is a parasitologist with the World H ealth Organisation Collaborating Centre for the Molecular Epidemiology of Parasitic Infections and State Agricultural Biotechnology Ce n tre, Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch WA 6150. 10WATER MARCH/APRIL 1999Cryptosporidium for sale Purified, freshly passaged, viable Cryptosporidium oocysts suitable for standardisation are now available on a regular basis from Murdoch University at a cost of $500 per 6 million oocysts. For more information contact:Dr Una Morgan morgan@numbat.murdoch.edu.au Fax:(08) 9310 4144 Tel: (08) 9360 2457 Prof. RCA Thompson andrew t@numbat.murdoch.edu.au Fax:(08) 9310 4144 Tel: (08) 9360 2466mWATERWATER TREATMENT OPTIONS FOR CRYPTOSPOR/0/UM AND GIARD/A B Murray, K Linnemann, K CraigAbstract Theprotozoa n parasites Cryptosporidium and Giardia are found in catchments and groundwater worldwide , and have recently caused widespread co ncern following their detection in Sydney. Treatment is made di ffi cult by their resistance to normal di sinfectio n measures (especially Cryptosporidium) and their relatively low infective dose. T here are trea tme nt options w hich, combined W1th appropriate catchment n1anagement and storage, will reduce the risk of these organisms entering the treated water system. Optimisation of co nventional filtration systems is fea sible, using particle counting instrume ntati on w hich is faster and m ore economical than counting th e actual oo/cysts. Advanced treatment technologies may be incorporated into new or existing treatment processes. T his paper reviews the rem.oval efficiencies of such system s. IntroductionC1yptosporidium and Giardia are parasitic protozoa whic h are found worldwide and may be p resent in most ca tchmen ts and groundwater in Australia, with the poten tial risk of contamination of urban and ru ral water supplies. T he organisms can only reproduce inside the gu t of animals (including hu mans) . However, Giardia cysts may survive in water for several months and Crypto sporidiwn oocysts m ay survive even longer, especially at low temperatures. The species of these protozoa w hich cause illness in humans are generally Cryptosporidiwn parvum and Giardia lamblia. D espite a lack of clear correlatio n b etween illness o utbreak s and levels of oo/cysts in water, both are known to have a relatively low infective dose (Craun et al., 1998). R ecent studies have shown that rainfall can increase the concen tration of protozoan oo/cysts in rivers by a number of pote ntial m echanisms, inclu ding re- su spe n sion of bo ttom sediments, soil and faecal matter and sewage system overflows (Atherholt etal. , 1998). T h e high levels of Clyptosporidium oocysts and Giardia cysts repo rted in Sydney's water supply system. in winter 1998 followed high rain fall even ts in the catchments. Giardia cysts can n ormally be controlled through effective physical removal and adequate chemical inactivation. Cryp tosporidium oocysts, however, are smaller than Giardia cysts and therefore m ore difficult to physically remove. They are al so almost completely resistant to chlorine-based disinfectants at normal concentrations and contact times, (see Table 1, from Langlais et al, 1991) and have been reported to survive 24 hou rs at a chlorine concen tratio n of 1,000 mg/L (Smith et al. , 1989). Protection of Raw Water Supplies The main focus of this paper is the op tions fo r trea tment p rocesses. However, for maximu m protection against waterborne Cryptosporidium and Giardia, there must be appropriate management of ca tchme nt, reservoir and reticulation, supported by effective..oo/cysts ca n concentrate in layers or pockets in reservoirs, parti cularly w hen there is a drought followed by heavy rainfall. Therefore, m onitoring at various depths of a reservoir is required, especially after heavy rain. Multiple drawoff levels w ill offer advantages in th e cleanest wate r. selectin g D estratifica tion syste ms may be investigated to de te rmine t heir effect on Cryptosporidium and Giardia. The water circulation provided w ill not only dilute concentrated pockets of oo/cysts bu t may also inactivate some oo/cysts by exposure to air and ultraviolet light. The water distribu tion system should be secured against re- contamination with sources of protozoan cysts. This can be achieved by regular ma intenance and monitoring and back0ow prevention . Biofilms on pipe surfaces may harbour protozoa w hi ch m ay be sloughed off by higher velocities. Effective Water Treatment If the raw water source is considered likely to become contaminated with Cryptosporidium and Giardia, aTable 1 Ct values for 99% inactivation at 5° C (mg. min/ L)OrganismCl 20.034- 0.05 E.coli 1.1-2.5 Polio v.1 0.01-6,480 Rotavirus 7.7 Naegieria 7,200 Cryptosporidium oocysts (90%) 30-630 Giardia muris cystsmonitori ng of raw and treated water and community health surveillance. Effec tive catchment managem ent would aim to protect the water source from contamination with human or animal faeces. Agricultural, residential, forestry and mining developments may be potential sources of faecal or other types of contamination in water supply catchments. A catchment-wide body with appro priate respon sibilities and powers may provide the best protection of water quality (McClellan , 1998). Cryptosporidium and GiardiaChloramine 95-180 770-3,740 3,810-6,480-7,200 1-400CI0 2Ozone0.02 0.4-0.75 0.2-0.6.7 0.1 - 0.2 0.2-2.1 0.006-0.06 3.7 0.75 78 5.0 7,2 - 18.5 1.8-2.0number o f short- , medium - and longte rm optio n s may be adopted to improve th e p erformance of water treatment plants (WTPs) for e nhanced removal of these organisms. A rapid resp onse to treating poo r quali ty water is shutting down the W TP after rain when very high turbidities are encountered or if high levels of Giardia or C1yptosporidium in the source water are suspec ted. This is feasible only if adequate raw and treated water storage capacity is available. Short- to m eclium- term approaches WATER MARCH/APRIL 199911WATER involve optimisation of the plant's process. Well-operated conventional treatment and direct/contact filtration plants can be expected to achieve 2 to 3 log removal of cysts and oocysts. Many plants, however, may only achieve 1 to 2 log removal. Medium - to long-term water treatm ent approaches may include additio n of new, more effective treatment barriers for Cryptosporidium and Giardia. Several researchers have examined a variety of treatment technologies which will provide furt her barriers to Giardia and Cryptosporidium in the water supply, some of which are discussed below.can be used to provide information and feedback for: • evaluation of WTP performance for the removal of cysts • chemical dosing and process optimisatio n • initiation of backwashing • monitoring filter ripening times. Proprietary software is normally provided by particle counter suppliers, enabling particle counting information for various particle size ranges to be logged and manipulated. T he software allows links to a WTP's central SCADA system, alarms and/or control systems for backwashing or filter-to-waste of ripening water.Particle Counting Instrumentation M onitoring to identify and achieve optimal performance should preferably incorporate particle counting information and turbidity measureme nts. Particle counting has several advantages over turbidime t ry becau se i t defines a greater n umber of parameters, covers a greater order of magnitude of results, and is more sensitive to water quality. Particle coun ters meas ure the nu mber of particles p er specifi ed volume of water, loggi ng seve ral parti cle size ba nd s simultaneously. T hey can give an instantaneous and low- cost indication of particle concentration in the 2- 12 µm size range of protozoan oo/cysts far more economically t han measurem en ts of actual oo/cysts. An illustration of the early breakth rough of particles in the oocyst range no t detectable by tu rbidity m easu reme nt is given in Figure 1, derived during p ilot trials fo r the Prospect T reatment Pla n t (Murray, 1994, 1995). Raw water p article counting ca n provide early warning of contamination. Particle counting of filtered waterWater Treatment Process Optimisation Operational approaches to optimise the removal o f Cryptosporidium and Giardia oo/cysts include: • optimising chemical dosing • minimising the effect of flow rate changes • optimising filter design and backwashi ng technique • minimising fil ter ripening • minimising recycli ng risks. Ma ny o f these options may be employed at established plants, depending on the design and layou t o f the plant. Some o ption s sho uld also be considered in the design of new W TPs. Studies have shown that optimised conventi onal treatment and even direct/contact fil tration p rocesses can achieve up to 4 log removal of oo/cysts. O ngerth and Pecorano (1995) fo und that direct filtratio n with dual media under optimised con ditions cou ld achieve approximately 3 log removal for Cryptosporidium oocysts and slightly better fo r Giardia. Sydney W
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