Water Journal September 1983 by australianwater

ISSN 0310-0367

Official Journal of the

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I Vol. 10, No. 3, Sept. 1983-$2.50 I Registered by Australia Post -

publication no. VBP 1394

Erosion before corrective measures

Same area after remedial work.

Before .. . Combination of structural works and vegetative protection .

The advantages and beauty of willows and poplars.

. After

Restoration by structural and vegetative works.

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3397HSE 10

WATER

FEDERAL PRESIDENT F. Bishop, Scott & Furphy , 390 St. Kilda Rd ., Albert Park, 3004

FEDERAL SECRET ARY F. J. Carter, Bo x A232 P.O. Sydney South, 2001 .

Officia l Journal of th e - ~A~u=s= r n=-A~L~IA~N~ 'WA TER AND WASTE WATER AS SOCIATIO N

FEDERAL TREASURER

Vol. 10, No. 3 September 1983

J. H. Greer, Cl- M.M.B.W .

625 Lt . Collins St. , Melbourne , 3000.

BRANCH SECRETARIES Canberra, A.C.T. J. E. Dymke, 4 St ory St. , Curtin , 2605. Office 062 (81 9385)

CONTENTS Viewpoint .................. . ....... ........ . . . . ... . .

Association News, Views and Comment ........ .. . ..... .

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

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

Alternatives to Chlorination for Water Disinfection -David Barnes .... . . ...... . . .. .... ... .. . ....... .

Water Quality Factors in Inland Waters - An Overview. Lake Eppalock - W.M.Drew.......... ..... ............. . . ..... .

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

New South Wales D. Russell , Camp Scott & Furphy , 781 Pac ifi c Highway , Chatswood 2067. (02 412 2688)

Victoria J. Park, S.R.W.S.C. Operator Training Centre , P.O. Bo x 409, Werribee, 3030 . (741 5844)

Queensland D. Pettigrew , C.I.G . Ltd ., P.O . Box 40, Rocklea 4106. (07 275 0111)

South Australia A. Glatz, State Water Laboratories , E. & W.S. Private Mail Bag , Âˇ Salisbury, 5108. (259 0319)

Western Australia R. Loo, 455 Beach Rd ., Carine, 6020. (09 447 6550)

Tasmania G. Nolan , 21 Browne St., W. Hobart , 7000. (002 28 0234)

Northern Territory M. Wyatt , P.O. Box 37283 Winnellie , N.T. 5789.

EDITORIAL & SUBSCRIPTION CORRESPONDENCE G. R. Goffin, 7 Mossman Dr., Eaglemont 3084 03 459 4346

COVER The scenes on the cover of this issue are from "Revegetating Victorian Streams " , a publication produced by the State Rivers and Water Supply Commission . For many years the Commission has been concerned that almost all plantings used to protect river improvement work were exotics - in particular willows and poplars. That these are so commonly used is understandable since there has been little information on alternative Australian species. Determining the most suitable species and, in particular, the identification of suitable native species for use whenever possible, has been a major objective of the Standing Consultative Committee on River Improvement. This committee was established in 1975 by the Commission and included representatives from the Forests Commission, the Ministry for Conservation, Department of Crown Lands and Survey, Association of Victorian River Improvement Trusts, Conservation Council of Victoria, Soil Conservation Authority and the Fisheries and Wildlife Division. The publication covers many aspects of revegetating streams and in cludes a guide to selected species for planting. Copies are available from the Public Relations Office, State Rivers and Water Supply Commission, 590 Orrong Road, Armadale, Victoria 3143.

ADVERTISING Miss Ann Sykes, Appita, 191 Royal Parade , Parkville 3052. 03 347 2377

The statements made or opinions expressed in ' Water' do not necessarily reflect the views of the Australian Water and Was tewater As sociation, its Council or committees. WATER Seprember, 1983

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WATER September, /983

EDITORIAL Chairman, E. A. Swinton F. R. Bishop B. P. Maguire Dr. Wayne Drew W. Rees J. H. Greer B. Robbins R. McGrath J.E. Dymke C. Weeks G. Nolan R.Vass G.Jackson Dr Barb. Bowles D. Simpson Editor: Publisher: G. R. Goffin A.W.W.A .

BRANCH CORRESPONDENTS

CANBERRA A.C.T. J.E. Dymke 4 Story St., Curtin 2605 Office 062 81 9385 NEW SOUTH WALES W. H. Rees ·Inv. Eng., Advance Planning M.W.S.&D.Bd. P.O. Box A53 Sydney South 2001 02 269 6595 VICTORIA R. Vass , M.M.B.W., P.O. Box 4342, Melbourne 3001 . 03 615 4362 QUEENSLAND D. A. Simpson Munro, Johnson & Ass . P/L 67 St. Pauls Terrace Brisbane 4000 07 221 6616 SOUTH AUSTRALIA B. P. Maguire I. & T. P. Branch E. & W. S. Dept. Victoria Sq. Adelaide 5000. 08 227 3966 WESTERN AUSTRALIA B. Robbins, Camp Scott & Furphy 47 Ord St ., W. Perth 6005 09 321 4582

TASMANIA G. Nolan , 21 Browne St., W. Hobart 7000. 002 28 0234 NORTHERN TERRITORY G. Jackson , P.O. Box 37283 Winnellie 5789, 089 84 3666.

VIEWPOINT THE 1982/83 DROUGHT BANE OR BLESSING? Nineteen eighty-two/ eighty-three was the driest year on record for much of south eastern Australia. Many urban users suffered restrictions, including, for example, most people in metropolitan Melbourne, and many irrigation areas were hard hit with shortfalls. Some storages were drawn down to such low levels that risks of restriction in the coming year are the highest yet. Low streamflows, and heavy grazing pressures on catchments, have led in many cases to poor water quality. Water agencies and governments must now ask questions such as:_ • what risk of shortage of supply to users is appropriate, are present risks satisfactory or too high, or could they be higher still, and what should be done to bring risks to appropriate levels? • in what circumstances is it appropriate to connect users to new or existing systems, and at what price and standards of supply? • is it appropriate to accept the poor quality of supply and the environmental effects of low quality and low streamflow; if not, what quality criteria and risks should be set, and what should be done to achieve them? There are no easy answers to these questions , but they must be answered as logically and as fully as possible, if we are to ensure effective planning and management of our water resources for the greatest benefit of the community . Solutions adopted to solve existing and emerging problems are likely to be very different than those in years gone by, when heroic works were the order of the day, and when as Bert Kelly, M.P. said so aptly, 'as election times approach, every politician fee ls a dam coming on'. It was not long ago that the water sector had little difficulty in securing all the funds it needed. The water agencies were among the largest spenders of State funds. Today that has all changed . Education, health and transport now take up the lion' s share of State recurrent funds . The present recession has meant greater calls for spending on welfare and housing. The drought has compounded the problem, with lower agricultural production and lower taxation revenue as a result. Bushfire emergencies, frost damage to crops, and flood damage have not helped. Today's community is better informed and more sophisticated . Its expectations are for improved services, but with increased attention to issues such as the environment. Governments are concerned to consult, and their ecbnomic and financial policies reflect a much greater concern with equity, efficient resource allocation, and stimulation of economic activity. As well, all Governments are concerned to reduce to a minimum the rising trend in rates and charges. In these circumstances, a number of States and agencies are responding not necessarily by further construction works, but by making it possible for communities to consider alternatives, such as demand management, as ways of matching needs to available resources. Thus, most States and agencies are now taking a path which involves: • greater efforts to plan effectively, for example, State water plan development in New South Wales and Victoria; c demand management; involving strategies such as pay-for-use pricing, the technology of efficient water use, and public awareness campaigns; • a shift in emphasis from major construction to effective and efficient system operation. The drought, despite its often serious impacts, may well serve a long-term beneficial purpose if it focuses our attention as an industry on the need for new and innovative approaches to old problems. Overseas experience shows that such paths can be followed; our challenge is to learn, to avoid others' errors, and to more effectively meet our society's challenges. I believe the A WWA has a vital role to play in assisting this process . JOHN SHEPHERD Director of Water Resources, Victoria WATER September, 1983

ASSOC/A TION NEWS VIEWS AND COMMENTS PRESIDENTIAL MESSAGE PATRON OF ASSOCIATION I am pleased to announce that His Excellency the Right Honourable Sir Ninian Stephen, AK, GCMG, GCVO, KBE, KStJ, Governor-General of the Commonwealth of Australia, acceded to the Association's invitation to become Patron of the Association, effective from 1st August, I 983.

DARWIN INTERNATIONAL SPECIALIST CONFERENCE By the time you receive this journal, the Specialist Conference on the Water Regime in relation to Mining, Milling and Waste Treatment with emphasis on Uranium Mining will have been concluded beneficially for all participants from within and without Australia. A small but able and energetic Conference Organizing Committee, led by Chairman John Paul and supported by his Executive, Ron Freyling and John Kenworthy together with a small band of helpers, have toiled hard and enthusiastically to make the Conference a success, both technically, socially and hopefully financially. Most members are well aware that the financial success of a conference depends largely upon the support and participation of members and the voluntary efforts of the Branch members.

AFFILIATIONS The recent dialogue with the Civil College of the Institution of Engineers, Australia has resulted in our Federal Secretary, John Carter, liaising directly with Robin Henderson of the I.E. Aust. Headquarters, Canberra, and a Committeeman from each State branch has been nominated to liaise with its respective I.E. Aust. Division in order that a co-operative and effective approach can be taken in regard to meetings, seminars and conventions of mutal interest to both organizations. Our Convention a nd Journal Papers will now be included on the computerised data base 'Waternet' of the American Water Works Association as well as the Water Research Centre (U.K.).

MANAGEMENT OF WATER AUTHORITIES Water and Sewerage Services are capital intensive, but have been severely restricted in capital expenditure over the last few years. As a result, ageing assets, the Australian economy in recession, little or not Gross Domestic Profit, and increasing Consumer Price Indices present a difficult scenario which militates against improvement of the systems . 6

WATER September, 1983

The industry problems are reflected in various Government strategies to improve performance by various forms of structural change in water and sewerage authorities, both large and small, in the States of Australia. Public participation and submissions from interested parties have been received by the various Governmental Committees, but the A WW A has not been encouraged to give assistance. While I do pretend that members of the Association are the only people who are cogni sant of the needs of the Water Industry, I believe members have much to offer. Normal Branch Meetings are planned on topics relevant to this subject later this year, and it is my hope that a National Seminar on the Management of Water Authorities can be arranged in 1984. Only good can. come from an open objective examination of our Industry, not only for the industry but for community at large.

Local Government Department as Executive Engineer (Chemical). He entered private practice in I 964 as a Consulting Analyst and Chemical Engineer and in this capacity became widely known and valued for his knowledge and competence. During his long professio_nal career, Alan was closely associated with the design, operation and maintenance of water supply and sewerage systems throughout Queensland and with corrosion and concrete and mortar leaching problems in the water and associated industries. He was an Honorary Life Member of the Institution of Engineers, Australia, the Royal Australian Chemical Institute, the Australian Water and Wastewater Association and the American Water and Wastewater Association .

W. G. VOLK 1925-1983

FRANK BISHOP Federal President

DARWIN CONFERENCE The International Specialists Conference held in Darwin, September 4-9th, has come and gone as we go to press. Our record of the activities will appear in the next issue. The Conference was something different for A WW A - a 'specialist' meeting in every sense of the word with a 'specialist' theme. As such, it was an innovation in the Association and a very successful one. More anon, in the meanwhile, congratulations to the hard-core of the Branch organisation, John Paul, John Kenworthy, Ron Freyling and their hard-working wives. *

Bill Volk died suddenly in Brisbane on June 24th at the age of 58. Educated in Charters Towers, he served four years with the RAAF and graduated from the University of Queensland in 1949. He joined the Brisbane City Council Department of Works and, until 1964 was associated with major water supply design, bridge design and water supply maintenance. In 1964 he joined the consulting organisation of Blain, Brem,ner and Wi lliams, firstly in Gladstone and after 1967 in Brisbane where he became an Associate Director and in 1981 a Director of the Company. He specialised in water and sewerage work and was associated with many treatment and distribution projects in Queensland. Bill was a Member of the I.E. Aust., a Registered Engineer, and Local Government Engineer and an active Member of the A WW A serving as President of the Queensland Branch and representing the branch for many years as Federal Councillor . He will be sad ly missed by his colleagues and associates in the Engineering Profession.

M. A. SIMMONS 1905-1983 We record with regret the passing of Alan Simmons and pay tribute to his lengthy association with the water industry and the Association, and his very considerable contribution to this field of activity. Alan was one of the first Graduates in Chemical Engineering from the Queensland University, in 1929. He joined the Brisbane City Council Water and Sewerage Department and remained with that organisation until 1949 when he moved to the

WESTERN AUSTRALIA BRANCH ACTIVITIES Our July Mini Symposium attracted an excellent attendance of 80 members and friends . Eight papers on 'state of the art' methods of Waste Water Treatment were presented by J. Holbrook, R. Loo, D. McClearie, R. Lugg, A. Gale, P. Dundan, H. Rule, K . Cadee.

ASSOC/A TION The symposium commenced around 3.30 p.m. in the afternoon and finished 8.00 p.m. in the evening with a congenial buffet meal and refreshments. The symposium gave members a much appreciated opportunity to learn of recent technical developments and to meet one another socially - congratulations to the organisers and all those who presented papers. Membership

From our somewhat humble beginnings in the '70s, we now have a membership of 188 including 20 sustaining members. We are fortunate indeed that the majority of members regularly attend our meetings and show a healthy interest in association activities. Annual General Meeting

On the 17th August, approximately 60 members and wives attended the Ann ual General Meeting which was held at the Swan Brewery. Brewery staff entertained us all with lashings of their finest product and a conducted tour of all operations of the brewery and associated museum. The tour was fo llowed by a short PR film on the brewing of beer. When we were still seated, President Noel Platell conducted the shortest Annual General Meeting on record (less than I 0 minutes!) a fact which was appreciated greatly by all those present. The company then retired to refresh their taste buds at the brewery's expense and to partake of a pleasant buffet-style dinner. Everybody enjoyed themselves immensely and it appeared that PR staff of Swan Brewery would have to eject a large group of hangers-on who remained after closing time. Office bearers and committee for the following year are: President, Noel' Platell; Vice President, Barry Robbins; Secretary, Rein Loo; Treasurer, Peter Verschuer. Committee: Peter Dundan, Bob Fimmel, John Holbrook, Brian Kavanagh, Don Montgomery, Barry Sanders, Neil Smith, Charles Tucak, Eddie Wajon.

NEW SOUTH WALES

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progress had been made in improving the quality of the river's water - the Royal Commission of 1902 commented on problems still in existence. It was suggested that the administraton of the river was like the river itself - rather murky, flowing slowly and even, on occasions, flowing backwards! Mr. Johnson felt progress has been made and a new agreement promises further improvement given co-operation. River water quality is superior to many of the major rivers overseas. The river receives little industrial and domestic wastes, the main problems being salinity, turbidity and nutrients. A start has been made on salin ity reduction - 11 schemes costing $32 million have been constructed since 1968. Water monitoring commenced five years ago to assist decision making. A hi gh light of the meeting was the presentation to Peter Hughes of Honorary Life Membership of the Association and a Service Award for his work as Federal Secretary between 1976 and 1980. In making the presentations, Federal President Frank Bishop spoke of Peter's hard work in improving the administration of the Association and of his continued interest in its work since becoming Engineer-in-Chief of the Sydney Water Board. In reply Peter expressed his pleasure at receiving the awards and spoke of the many fine people he had been associated with during his term of office. At the business meeting, the following office-bearers were declared elected for 1983/84: President, Lance Bowen; V. President, Timonthy Smyth; Secretary, David Russell; Treasurer, Fred Randall; Committee: Norm Brady, Hans Bandier, Jeff Brown, Chris Davis, Mike Dureau, Graeme Douglass, John Es lake, David Gorman, Ii:n Law, Tom Lawson, Peter Nixey, Rob Pearman, Bill Rees, Errol Samuel, Tas Twyman. Thanks were expressed to retiring Committee members - Trevor Judell, Dick Ash, Jim Olliff and David Stevens who served the Association with great distinction over many years. The meeting closed with a convivial dinner at the Club. Half Yearly Social Function

BRANCH ACTIVITIES

Hardly recovered from the Federal Convention, the Branch embarked on a busy programme of activity. Annual General Meeting

On 17th August at the Royal Automobile Club, 60 members met to conduct the necessary business and to hear Mr. Ken Johnson, Chief Executive of the River Murray Commission speak on 'Keeping the Murray clean - the role of the River Murray Commission'. The Murray (and Darling) is the most important river basin in Austra lia, supporting a population of two million people, half the nation's agricu lture and three quarters of its irrigation. In some ways it appears that little

On June 17th the Branch enjoyed an evening at the Cyprus-Hellene Club and a dinner of traditional Greek dishes. The attendance was good, about 120 alth ough the promised Greek music was a little on the quiet side. Nostalgia was shared by a number seen later reminiscing upon their 'Idyllic' days over a glass of Retsina or Ouzo. Lecture Evening

Despite a train strike, more than 50 members gathered in the Water Board Theatrette on 29th June to hear a lecture entitled 'Effective Organics Removal by Conventional Water Treatment Processes' given by Associate Professor Michael Semmens, M.A., M.Sc., Ph.D. Professor Semmens is currently on sabbatical leave from the

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COMMENrJ'

University of Minnesota and held a temporary appointment in the School of Civil Engineering at the University of New South Wales until August 1983. Dr. Semmens has worked upon and evaluated the effectiveness of conventional treatment in several areas in the USA. He spoke on organic removal, the effectiveness of granulated activated carbon and the influence of pretreatment by coagulation. A lively discussion followed the presentation of the paper. Inspection Dockyard

Garden Island Naval

On Sunday, 7th August on a perfect winter day some 60 members and their families gathered at Garden Island Fleet Base and Naval Dockyard for a tour of inspection and picnic lunch. The tour was guided by Mr. Fred Randall, Superintendent of Works and Planning, ably assisted by his son, also Fred, who is a Branch Committeeman and now Treasurer. The party gained fascinating glimpses of early days of the Dockyard dating from the 1880s including the century old figurehead of the frigate, HMS Penguin which operated in Australian waters. A 20 year plan of modernisation is being implemented and some of the work was seen during the visit. The tour concluded with a barbecue while enjoying the harbour views and some energetic members of the party toured the guided missile destroyer, HMAS Brisbane which was open for public inspection. New Members

Dorr Oliver Pty. Ltd. is now a Sustaining Member, Messrs. P . G. Coleman, B. W. Cooper, W. E. Day, JC G. Friend, R. B. Grover, G. L. Hanna, R. A. Minshull, J.E. Sutton and W. M. Wood are Members and Messrs. J. E. Hansen, J. K. Morris and Ms. R. Redrup, are Associate Members welcome. Coming Events

23rd September - Dinner Dance at the Sebel Town House. Guest speaker will be Mr. Ted Bryden-Brown, Public Affairs Director at Taronga Zoo. 19th October - Lecture by Mr. Ian Law (Camp Scott and Furphy) on South African experience in industrial wastewater treatment and nutrient removal. 23rd November - Lecture by Mr. Joe Weinberg (Israel Desalination Engineering Ltd.) - a state of the art address on desalination, evaporation and distillation techniques. 2nd December - Christmas Party, Northbridge Golf Club . NEWCASTLE GROUP

The 63rd General Meeting of the Newcastle Sub-Branch was held at the Hunter District Water Board on the 23rd May. Paul Dougas from Sinclair Knight and Partners spoke on 'Liquid Waste Treatment'. The speaker had WATER September. /983

ASSOC/A TION

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recently visited a number of liquid waste treat ment fac ilities in England, Europe and America and attended a major conference in Denmark. Mr. Dougas's well illustrated address referred to specific projects on wh ich his firm had been engaged . Mr. T. Jenkins from th e Hunter Dist rict Water Board was guest speaker at the 64th General Meeting on the 20th June. Mr. Jenkin spoke on the topic 'Destatification of Chichester Dam' . The speaker covered a literature search made to date and the recently installed aeration equipment at th e dam site. A very successfu l fami ly combining perfect weather and attendance approach ing 80 persons with the hospitality of Leon Sivyer and his fami ly was held at Leon' s property on the Upper Allen River on the 10th July. The 65th General Meeting at the Uni versity of Newcastle on the 27th Jul y and was a joint meeting with the I.E. Aust. Mr. A. Pepper and Mr. T . Angus from the Hunter District Water Board spoke on the 'Post-tensioning of C hichester Dam'. The talk included background on the dam st ru cture, site geo lo gy and on-site testing met hod s employed . The 66th General Meeting took the form of a follow-up excursion to Chichester Dam on 30th July. Some 30 people enjoyed the perfect weather to view the 93 re-stressible a nchor s being installed . Followi ng the meet ing a picnic/ barbeque was held at the Jerusalem Creek Picnic Area in the Telegherry State Forest . Future Meetings

Friday, 16th September - 16th Annual General Meeting. Monday, 17th October - 68th General Meeting Mr. R. Cadde n of th e Metropolitan Water Sewerage and Drainage Board will speak on ' Insitu lining of sewers'.

VICTORIA BRANCH ACTIVITIES

The May meeting was an excursion into the past, looking at the beginning of the water treatment industry in Australia, through the vivid memory of Mick Martin, the founder of Sulphates Pty. Ltd. and Filtration and Water Softening Pty. Ltd. Through these two companies, in the 1920s and 30s Mick developed Australian technology, both in chemistry and engineering, applying coagulation and filtration to swimming pools, industrial and municipal water treatment. Mick Martin , at th e noble age of 84, still spry and eloquent, addressed a crowded meeting for an hour , and joined in discussion afterwards . He told of his first venture into chemistry in his mother's kitchen, trying to make aluminium metal using clay in lieu of bauxite, so that the Allied fighter planes could be made of something stronger than spruce and canvas. However, the war ended, and he had 8

WATER September, /983

NEWS

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VIEWS

· the intermediate, alum inium sulphate, which could be so so me use. He won a contract from APM - and the business set off. Paton and Baldwin's brand new mill in Launceston, the YMCA pool in Melbourne, a bauxite mine in Gippsland, a factory in Yarravi lle, and, at 28 years old , he was off and runn ing. Mick developed firm ideas on the subject of backwashing of sand filters, disdain ing both the British and the American techniques. Hi s automatic filters were installed all over Australi a, and st ill run to th is day. Both the water treatment industry and th e chemical industry of Australi a owe a debt to Mick Martin and we were pr ivi leged to listen to a grand old man and pioneer telling hi sto ry as hi s own story. For the June meeting Trevor Ri chards of State Rivers and Water Supply Commission asked us 'why design PVC pipe for a li fe of 11 400 000 years when you will have retired in 50 years time?' The bas ics of thermoplastic engineering were graphically described, with exhibits, and passing references to the effect of Melbourne's cold weather on rigidity. The creep phenomenon in ductile fract ure has a logarit hmic time exponent (which explai ns extrapolation to mi ll ions of years) but choice of more suitable factors of safety can yield substan tial econom ies. Trevor spoke of the observation of a number of anoma lous brittle fractures in high pressure PVC pipelines in the Commission's system. The cracks a ll commence at some foreign inclusion causing localised stresses, but are more related to incompletely polymerised material. A simple test introduced by the Plastics Institute now ensures no substandard products . The July meeting saw a first for the Branch with a mini-seminar on Anaerobic Sludge Digestion. John Parker of Water Science Laboratories moderated over the proceedings. Excellent presentations on the subject were given by Kevin Kirby CS IRO, Johnat han Crokett, Gutteridge Hask ins & Davey and Ian Law, Camp Scott & Furphy. Over 40 people attended the AGM in August. Highlights included the presentation of life membership to Ken Wood, who served the Branch for over 11 years as Treasurer and the election of Alan Howard, EiC of both the Ballaarat Water Commissioners and the Ballaarat Sewerage Authority, to the branch presidency. The audience was treated to an excellent presentation by the outgoing president Jan Lowther on the subject 'Chlorination - has it a fut ure?' Ian spoke of his experiences with the treatment tech nique at the Geelong Water Trust where he is the Chief Chemist. The answer was 'Yes, Chlori nation has a future ' as app li cation in service basins and mains in the Geelong system has been most successfu l in disinfecting bacterially contaminated water. STATE NEWS

More news on the drought in Victoria . While much of the State has had heavy and

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COMMENT

significant winter rain fa lls, Melbourn e's water supply catchments continue to receive well below average rain . Up to 15th August the catchment monthly aggregated rainfall was on ly 28 mm compared wit h a long term August monthly average of 135 mm. Streamflows harvested into the reservo irs were 47 per cent below Aug~st average. Restrictions are sti ll in force. The giant 1.1 million megalitre Thomson storage, being bui lt by the MMBW on the Thomson River north of Moe in Central Gippsland, passed a ' milestone ' during mid July . The stoplogs were placed on the diversion tunnel thus commencing storage behind the 160 m high wal l. It is expected the water level, which was 25 m up mid August, will be kept below the 60 m level until late Autumn next year when the out let towers are expected to be completed.

QUEENSLAND BRANCH ACTIVITIES

The 1983/84 Committee is essentiall y as for the prev ious year with Derek Brady and Howard Wa llace, replacing Co l Richardso n. Many thanks to Col Richardson for his services to the Committee. Derek is a Senior Lecturer at the University of Queensland and is co-author of the paper 'A method for Estimating Odour Concentrati ons Arou nd Wastewater Treatment Plants' whi ch won the Dr. Michael Flynn award for the best paper at the Tenth Federal Convention in Sydney in April. Howard Wa llace has recently been promoted to the position of Chief Engineer, Investigation and Review Section with the Department of Local Government. He was prev ious ly Deput~ Director of the Water Quali ty Council. The Committee, elected at the AGM on August 3rd comprises: President, John Ryan; Vice President, Keith Strickland; Immediate Past P resident , Brian Rigden; Treasurer, Julie Ivison; Ass istant Treasurer, David Simpson; Secretary, Don Mackay; Assistant Secretary, David Pettigrew; Membership Secretary, Michael Bowe; Journal Correspondent, David Simpson; Programme Officer , Rod Lehmann; Committeemen: Derek Brady, Humphrey Desmond, Jack O'Co nnor , Alan Pettigrew, Billy Solly, Howard Wallace, Norm Whyte. At the meeting, a Life Membership Certificate was presented to Murray Allen for services to the Associat ion. Murray worked for Australian Paper Manufacturers for the whole of his working life, except for a stint in the army during World War II and from 1959 until his retirement in 1976 he was Technical Superintendent at the Petrie mill. He was a foundation member of A WW A (1962) and has been an active member since that year. He was Queensland Branch Vice President in 1969/70 and 70/71, President in 71/ 72 and 72/73, and Federal Coun ci ll or for six years. For the AGM, Tom Fenwick, Senior

ASSOCIATION Engineer Special Proj ects, Queensland Water Res ources Commission presented a ta lk on ' The Burdekin Ri ver Project' . Thi s project which will be the largest of its type in Queensland a nd probab ly A ustra li a, involves a 37 m high mass concrete gravity and is directed principall y to irri gation. The subject could provide a n interes ting pa per for Water. At th e meeting on 6th July 1983 , Ken Hartley of Gutterid ge Haskin s & Davey Pty. Ltd. presented an excellent paper on ' Bundamba Wastewater Treatment Plant - The First Six Months'. Th e paper desc ribes a mong other things how a constant sludge age is maintained in the oxidation ditc h . Th e Regional Conference held at Cedar Lak e Resort I 9th-21st A ugust was attended by 50 delega tes a nd 14 wives. The theme was 'Effluent Disposal Methods'. · Eight papers were presented as follo ws: • The Go ld Coast C ity Council Sewerage System - Where are we going Noel Hodges a nd Geoff Hamilton - Gold Coast City Co un cil. • The Albert Shire Co uncil Sewerage System Barry Spall - Albert Shire Council. • Ocean Disposal Systems - A Case History John King and Angus Jackson - Gold Coas t Cit y Council • Tertiary Systems Ca rey Anderso n - William Boby & Co. (Aust.) Pty. Ltd. • Determination of E ffluent Stand a rd s for Ri ver Discharges Bob Craswell - Water Quality Co uncil • Land Disposal System s - A Case History Graham Thompsen John Wi lson & Partners • Domestic On-site Treatment Systems Sta te of the Art Chris Palmer Department of Local Government • Dom es ti c On-site Treatment Systems H ea lth Aspects Dr. Tony Bourke - Department of H ea lth Copies of th e papers a re avai lable from the Queens land Branch at a nomin al cha rge.

The conference at the Malendinar W.T . plant.

At t he Con ference dinner Mr. Lorin Hawes, th e prev ious owner of the Boomerang Factory at the Gold Coas t was the Guest Speaker.

•

NEWS

•

.LJ -

·"'

·...

-- ~,.

•

....

•

VIEWS

..:

,'k

...

Merrimac WWP-clarifiers and lagoons.

On Sunday 2 1st A ugust 1983 , technical inspecti o ns of the Hinze Dam Lower Intake Pumpin g Station, Malendinar Water Purification Plant and Merrimac Wastewater Treatment Plant was fo llowed by a lunchtime barbecue nea r the Nerang Ri ver. OBITUARY

It is with regret that Queensland Branch records the deaths of two of its members . M.A. SIMMONDS (1905- 1983) Allan Simmo nds died quietly on the 12th Jun e, 1983, a t th e age of 78 years, a fter a period of ill health. M r. Simmond s was a Life Member of A WW A. W. G. VOLK (1925- 1983)

Bi ll Volk died suddenly in Brisbane on Jun e 24th at th e early age of 58 . A tribute to these two members a ppears earlier in t he Association News in this iss ue.

SOUTH AUSTRALIA BRANCH ACTIVITIES

In recent years the use of oxygen has become increas ingly popular, pa rticularly in Australia, as a means of conditioning and treating wastewaters. Th is topic was furth er ex plored a t the meeting held on 16th June , l 983 when Mr. Merv Ogston, Env iroshi eld Engineer with CIG Ltd. in Adelaide spo ke on 'Use of Oxygen in the Wastewater Indu stry' . Mr. Ogston's informati ve talk , which was well illustrated wit h the aid of slides together with a photographic display, covered many aspects of th e subj ect including methods of oxygen produ ction , on-site storage, dissol ving techniques a nd th e use of oxygen for odour co ntrol, in -sewer trea tm ent and treatment pla nt augmentation. Th e use of oxygen inj ection for odour co ntrol is mainl y directed towa rds the control of hydrogen sulphide in sewe rs - in main o xygen treat ment has been described in the paper o n Boulder Bay in th e June iss ue of Water. Oxygen inj ection at treatm ent pla nts has been used success full y to upgrade the trea tment capacity of ex isting fac iliti es, or to improve efflue nt quality. At Rosney in Tasmania, the required improvement in treatment peforma nce was achi eved usin g a modifi ed ac-

COMMENT

tivated sludge process together with oxygen injection. A highl y successful combined meeting between the S.A. Branch, the S .A. Civil and Structural Branch of the l. E. Au st. and the H ydrological Society of S.A. was held on 5th July, 1983. Mr. G. F. McIntosh, a Supervising Planning Engineer from Water Resources Branch of th e E .W. S. Department addressed an audience of about 90 on a subj ect particularly relevant to South Australia, namely, 'The Control of Salt Flow in the River Murray'. Mr. McIntosh introduced hi s topic by outlining the sources of both natural and man-induced salt inflows into the River Murray and the manner in wh ich these progressively accumulate in the river as it moves downstream. He then elaborated on the current status of investigations into the economic impact salinity was having on domestic, indust rial and agricultural uses of water in South Austra li a. To co nclude his presentation, Mr. McIntosh described measures currently being underta ken to mitigate the effects of salinity through the intercept ion and di sposal of saline inflows before they reach t he river. Major drainage schemes in Sout h Australia, include the Noora Basin , Rufus River and Berri-Cobdogla schemes . Membership

The Co mmittee extends a warm welcome to new members, Messrs Collin s, Cook, Dunsford , Wi lby, Delaverde, H es keth , Yerre l, Hau ghey, Ochota, Joll y (st udent) , Woods (student) and to a new sustaining m e mb e r , U ltr av io le t Techno lo gy of A ustra lasia . The Committee also regrets to record the death of Peter Waller on 13th July, 1983. P eter was a long sta nding Branch member and wi ll be sadly mi ssed by his many acquaintances in the A WW A.

Coming Events

September 23 - Ann ual General Meeting. Selected speakers from the State Water Laboratories of the EWS Department will give a presentation on 'Chloramination', an alternati ve water supply disinfection process currently under investigation by the EWS Department. · November II - Annual Guest Night. Dr. Frank Sear from the Department of Classics at Ade laide Uni ve rsit y will give an authoritative talk on ' Water Supply Systems of Ancient Rome'. STATE NEWS

The State Government has approved $ 1.65 million to upgrade water supplies to th e Ade laide Hills town of St irling, Crafers, H eathfield and Ald ga te in order to cater for the rapidl y increasing population in the area. The upgraded sys tem will provide for future growth in th e townships, but will also give residents a guaranteed water supply in the WATER Seprember, /983

.BRANCH NEWS (cont'd)

CALENDAR 1983-1984

event of electricity blackouts and bushfires. The upgrading work is expected to be completed by June 1984. Âˇ Highly turbid water entered the River Murray early in July as floodwaters from the River Darling flowed into South Australia. By late July the front of highly turbid water had reached the river towns of Mannum, Murray Bridge and Tailem Bend, and by early August had reached the Murray mouth at Goolwa. Samples taken at various locations along the river indicated that the peak turbidity was approximately 400 NTU, the highest level recorded in the River since I 947. Turbidities of about 300 NTU are expected to persist until about the end of September, after which they should steadily decline to about 100 NTU by the end of the year. Country areas of the state supplied directly from the River are the most adversely affected as a result of these highly turbid floodwaters. Unfortunately there is no current feasible way of significantly reducing turbidities in supply to these areas. Proposals for pumping and treatment strategies to significantly reduce the turbidity in River Murray water supplied to consumers in Metropolitan Adelaide are being developed by the EWS Department and will be implemented if and when required . River Darling floodwaters have caused turbidity increases in River Murray water, but have also reduced salinity levels through dilution to their lowest levels for many years, and have enabled Lakes Alexandria and Albert to be flushed and refilled with low-salinity water. The substantial increased flows in the River Murray have also been of considerable benefit to the Murray Mouth and the Coorong. It is estimated that the natural scouring of the Murray Mouth as a result of the floodwaters has saved the State Government up to $200,000 in opening the mouth artificially.

CHISHOLM INSTITUTE OF TECHNOLOGY

WATER QUALITY SYMPOSIUM Nov. 21-22 -

1983

The Role of Particulate Matter in the Transport and Fate of Pollutants

Keynote speaker, Dr. Rod Allan, Chief of Environmental Contaminants Div. at the Canadian National Water Research In stit ute will be speaking on the 'Transport of Heavy Metals and Tox ic Organics with Particulate Matter' and 'Bio-availability of Particulate Associated Toxic Organics' and will be supported by other eminent scientists. Details: Mr. Tom Dav ies, Co-ordinator, Water Studies Centre, Chisho lm Inst. of Technology, P.O. Box Âˇ197, Cau lfield East, Vic. 3145. 10

WATER Sep/ember. /983

October 2- 7, Atlanta, U .S.A WPCF Conference . October 3-6, Tel Aviv, Israel Agritech '83 .

1984 February 6-10, Canberra, A.C.T. 5th A WW A Summer School.

October 5-7, Amsterdam, Netherlands Oxidation Ditch Technology .

March 25-29, Bet Dagan, Israel Soil Salinity Under Irrigation Processes and Management.

October 6-8, Stuttgart, W. Germany Int. Seminar, Rotating Biological Discs .

April 2-6, Brisbane, ,Australia Annual Engineering Conference, I.E . Aust.

October 9-13, San Antonia, U.S.A. 19th American Water Resources Conference and Symposium (AWRA). October 14-23 , Moscow, U.S.S.R. Water Management. October 17-22, Bern, Switzerland Introductory Course on Tracer Hydrology . October 18-20, Knoxville, Ten., U.S .A. Lake/ Reservoir Management October 25-27, Innsbruck, Austria 5th Int. Symposium on Internal and External Protection of Pipes. October 25-27, Capri, Italy Int. Conference on the Modern Approach to Groundwater Management. October 26-27, New York, U .S.A . World Congress on Coating Systems for Bridges and Steel Structures. October 27-28, Vancouver, Canada Lake Restoration Protection Conference. November ? , Brisbane, Australia Metal Structures Conference.

April 9-13, Sydney, Aust alia 38th Annual Conference of Appita . April 10-12, E. Kilbride, Scotland Flow Measurement in the Water Industry . April 11-13, Uni. of Southampton, U.K. Int. Conference on Hydraulic Design in Water Resource Engineering. April 16-18, Adeliade, Sth. Australia 5th Int. Conference on Expansive Soils. April 24-25, Antwerp, Belgium Electrical Magnetic Separation of Filtration Technology . May ? , Canberra, Australia 54th ANZAAS Congress May 22-26, Munich, W. Germany European Sewage and Refuse Symposium (EAS). May 28-June 2, Colorado, USA 12th . Int. Congress on Irrigation and Drainage. June 10-12,.Quebec, Canada Syposium-Watefshed Chemistry.

November 5-11, Jakarta, Indonesia Asia Pacific Water Supply Conference.

June 18-22, Vermont, U.S.A. 5th International Conference on Finite Elements in Water Resources

November 8-10, Hobart, Australia Hydrology and Water Resources Symposium.

June 24, Denver, U.S.A. Int. Symposium on Impermeable Barriers for Soil and Rock.

November 8-10, Jakarta, Indonesia Asia Pacific Water Supply Conference.

July 15-20, Cambridge, U.K. Int. Conference on Ion Exchange .

November 20, Cambridge, U.K. Conference on Water and Development in Asia.

September 10-14, Stockholm, Sweden Int . Symposium on Balances of Chemical Substances in Water.

November 22-24, Canberra, Australia Workshop on Water Resource Data.

September 17-20, Amsterdam, Netherlands 12th International Conference on Water Pollution Research and Control, IA WPRC.

November JO-December 2, Canberra, Australia Symposium on Prediction in Water. December 5-9, Sydney, N.S.W. Int. Conference-Groundwater and Man.

September 17-20, Amsterdam, Netherlands AQUATECH '83-International Water Technology Exhibition .

December 7-15, San Francisco, U.S.A. Symposium on Parameter Estimation for Groundwater Models

September 30-Oct. 5th, New Orleans, U.S.A. WPCF Conference.

TECHNICAL INTERESTS INTERACTIVE COMPUTER GRAPHICS FOR WATER RESOURCE PLANNING Professor Daniel Loucks of the Department of Environmental Engineering at Cornell University will commence a three week lecture tour on November 5th . The tour programme includes: • Keynote address at the Hydrology and Water Resource Symposium, Hobart, Nov. 7-10 • Seminars at the Universities of Melbourne and Monash • A teaching course at the University of NSW • Address at ACADS functions and at the annual general meeting of the Victorian Water Engineering General Committee, Nov. 27th • Workshop organised by ACADS Queensland Water Engineering Technical Committee

Enquiries to: the Association for Computer Aided Design (ACADS) in each state or ACADS Head Office, 576 St. Kilda Rd., Melbourne 3004

WATER RESEARCH FOUNDATION

REFERENCE FACILITIES The Foundation's Water Reference Library can consult networks in the USA, Canada and Australia providing access to major water related data bases including: - Water Resources Abstracts - Aqualine - BHRA Fluid Engineer - Compendex - NTIS - Watrnet - Delft Hydro - Australian Bibliography on Agriculture - Aquatic Sciences and Fisheries Abstracts Costs of on-line searches vary between $50-$70, $100 in exceptional cases Enquiries to Librarian, Water Reference Library, King St ., Manly Vale , NSW

INST. OF WATER ENGINEERS & SCIENTISTS

SYMPOSIUM ON DETERIORATION OF UNDERGROUND ASSETS London -

CONFERENCE

WATER & WASTEWATER TREATMENT AND DESALINATION Sydney -Nov. 21-22

Organised by Israel Desalination Engineering (Zarchin Process) Ltd and Minedrill Pty . Ltd . the Conference will include presentations and discussion on: • Water treatment and desalinationadvanced technology • Low temperature evaporators, scale prevention techniques, dual purpose plants in power stations • Arid Zones - brackish and seawater desalination • Industrial wastes - ultimate zero discharge • Industrial water supply for coal and copper mines • Effluent treatment for power stations • New developments Enquiries : Miss J. Lawrence , Minedrill Trading & Transport Pty. Ltd ., GPO Box 990, Sydney 2001

7-8th Dec. 1983

INTERNATIONAL CONFERENCE

GROUNDWATER AND MAN Sydney -

5-9 December '83

Sponsored by Australian Water Resources Council with Australian Academy of Science, Int. Association of Hydrologists, Int. Association of Hydrological Sc iences Three main Themes: • Investigation and Assessment of Groundwater Resources • Groundwater and the Environment • Groundwater and Development

For all particulars and details of accommodation available: The Secretary , Groundwater and Man Conference, Australian Convention & Travel Services Pty. Ltd ., PO Box 1929, Canberra City, ACT 2601

* AMERICAN WATERWORKS ASSOCIATION

FUTURE OF WATER REUSE Symposium -

San Diego,August 1984

CALL FOR PAPERS

Promoted by the deteriorating state of underground pipelines and sewers and the extraordinary pressures on financial resources the symposium will be directed to problems and their source, remedial actions of most value and the total economic approach

This week long symposium will be directed entifely to renovation , recycling and reuse of wastewater by individuals, municipalities, industries and agriculture

Details : Secretary, 31 High Holborn, London , WCIV 5AX, England .

Abstracts (10 copies) of not more than 500 words covering proposed papers and giving all details, must be submitted by October 31st to:

MEMBRANE TECHNOLOGY

John DeBoer, Water Reuse Symposium 111 , AWWA Research Foundation , 6666 West Quincey Ave., Denver, Col. 80235, USA

Sydney -

Nov. 8-10

An International Conference will examine new developments and commercial opportunities in a wide range of technologies including: Electro-dialysis, reverse osmosis and ultra filtration along with uses in effluent treatment, biomedical devices, gas purification and other areas. A half day will be devoted to commercial opportunities. Details : Dr. A. G. Fane, School of Chemical Eng. and Ind . Chemistry., University of N.S.W., PO Box 1, Kensington 2033.

A.W.W.A.

ELEVENTH FEDERAL CONVENTION MELBOURNE, AUST.

April 26-May 3, 1985 WATER September, 1983

ALTERNATIVES TO CHLORINATION FOR WATER DISINFECTION David Barnes SUMMARY

Ozone a nd chlorine diox ide are used overseas as water di sinfectant s, while ultraviolet radiation• has some ex ist ing specialist water disin fect ion applications. Of the chemical disin fecta nts ozo ne is the most powerfu l, whi le chlorine dioxide also is more effective than ch lorine. The partial destruct ion of some com plex organic molecules can lead to the formation of by-products such as quinones, the hea lth effects of which are un certain . T he oxidant end-products of chlorin e dioxid e are reported to interfere with blood funct ion and a recommended residua l concentration limit is 0. 5mg/ L. T he alternative disinfectants are all more expensive than chlorin e. Chl orine dioxide and ultraviolet light do no t ge nerate triha lomethones, ozone on ly genera tes brominated met ha nes in the presence of bromide ions. 1. INTRODUCTION

A range o f disinfectants has been used or researched for poss ibl e use ', these include in addition to chlorine and hypochlorites • ozone • chlorine dioxide • ultraviolet light • chloramines • bromine chloride • potassium perm anga nate • hydrogen peroxide • heat • silver • ultrasonics • filtration • extremes of pH Ozone and chlorine dioxide are used in E urope and North America for potable water disinfection, ultraviolet irradiat ion is used in Au stralia for some speciali st application s, for example , water treatm ent in shell fish cul ture, these alternat ive disi nfectants wi ll be discussed in this paper. Of the other disinfectants ch lorami nes are used to provide a stab le residual, the biocida l power of chloram ines is significantly less than that of chlorin e, (approximately 25 times less). Bromine ch loride, iodine, potassium permanganate and hydrogen peroxide are all effective disi nfectants which have been in vestigated as alternatives to chlorine but have not been widely used in full scale plants but are used for small scale or emergency disaster applicat ions. Heat is the trad itional emergency disinfectant , boi ling water for approximately 20 minutes under normal conditions will kill the majority of pathogens, care has to be exercised as the boiled water contains no residual once it has cooled . Silver in low concentrations acts as a long term disinfectant for waters which contain little particulate or organic material. Ultrasonics can di sintegrate microorganisms, while ultra filtration of waters can remove microorganisms, these methods are used for small sca le or research applications such as the production of microbial free water for media formu lation. Raising the pH to greater than 12 or less than 2 will kill microorganisms, as with many of the other alternative disin fectants such an option will be relatively expensive and is only considered for small scale, emergency or speciali st applications. The basis upon which disinfectants have to be compared ' has to consider their ability to ki ll pat hogens and any side effects or res iduals. The requirements of a disinfectant can be summ arised • Ability to kill pathogens under normal environmental conditi ons, such as those of pH, temperature and turbidity.

Dr. Da vid Barnes is Associate Professor in the Departmenl of Wa ter Engineering of the University of New South Wales. This paper was presented to the 'Seminar on Water Disinfection ' conducted in Adelaide by the So uth A ustralian Branch of the Association on July 23rd 1982. 12

WATER September, 1983

•

Any end-products, by-products or res idua ls shou ld be non toxic to man. • The process shou ld be inexpensive in both capital and operat ing costs. • Some disi nfec tant residual should be provided to protect the water during di stribution. • The disinfected water should be neither unpalatable nor obnox ious. • The disinfectant should be easy and safe to tra nsport, store a nd di spense. • Analysis of the dose, residual, end -produ cts a nd by-prod ucts should be simple and inexpe nsive. • The water fo r supply a nd di stribu tion should be non corrosive . It is unreal istic to expect any si ngle di sinfectant to meet all of these conditions for all types of raw water. A ll that can be expected is that for a pa rticular suppl y a nd situation one or several o f the co nditi ons wi ll be critica l and a disinfectant ca n be used as the best option for that location. The limitations of space prevent a detailed discussion of all of these conditions for the three di sinfectants. Th e paper will concentrate upon the particul ar requirements for th e disin fec tant , pathogen or indicato r organism kill rates and end-prod uct and byproduct production. A preliminary di sc uss ion of relative costs will be mad e but aspects such as corrosivity and analysis will not be attempted. The chemica l analys is of certain of the species such as ozone residual is an area of specialist interest beyond the scope of this di scuss ion. 2. OZONE

2.1 Generation

Ozone is generated by passing an electric di schar~e through clean dry air or oxygen. The electri c current dissociates some of th e oxygen molecul e which ca n reform as a three oxygen atom molec ule. 30, .= 20, The resultant ozone is a very strong oxidant which ca n be 'smelt' in the air at less than 0 . 1ppm weight per weigfit. The species is tox ic to man attacking the eyes, nose and throat. Th is high chemi ca l activity is th e basis of ozone's ability to kill pa thogens and ozone is used in approximately 1,000 water treatment plants mainl y in Europe and in some other countries including Canada' . To achieve reliable and effective ozonation of oxygen th e feed gas must be particle free and dry. Pretreatment particu larly of air is required to filter and dessicate the gas pri or to the generator. This pretreatment ca n include compression, water separation , refrigerant drying and drying towers packed with dessicant such as a mixture of activated alumina, mol ec ular sieves and alumina balls'. The generation of ozone decreases substantia ll y if moi sture is present in the gases to be ozonated. For example a dew point of less than - 50°C representing less th an 24p pm of water in air by weight resu lt ed in efficient ozone production' . At a dew point of - 40°C ozone production was reduced by 4% and by a dew point of - 20°c (1 50pp m water by weight) was reduced by 15% . At hi gher water concentrations the efficiency of ozonation decreases rapid ly until the generator short circui ts ('flooding ' ), damaging the generator a nd producing no ozone. A generator is constructed as a relatively small unit which contains closely spaced anodes a nd cathodes . The production of ozone from a given unit will depend upon the flow rate of purified gas through the genera tor and the power applied. A mappin g diagram can be prepared for the generato r' such as that in Figure I for th e ozone production from air. Clearly higher ozone co ncentrations are produced at lower flow rates, however the overall costs tend to be lower at high flow rates. Fo r exam ple to ge nerate 5mg/ L of ozone requires 33.3kWh/ kg0, at a flow rate of I0L/min , 16.7 kWh / kg0, at 50L/ min and 15.3kWh/ kg0, at 120L/min. Additionally at th e lo w flo w rate

10 l / m i n .

"'E C 0

~ C

~ 10

"'0 C

1500

500 Power W

Figure I. Influence of flow rate and power on ozone concentration (after ref. 4). · approx imately 10 times more generator units are required than for the 120L/ min now rate. For a n efficient ozo ne generat io n syste m ca re is required to operate th e pretreatment effecti ve ly and to unders tand th e impli cations of no w and power respo nses of the generator. 2.2 Solubility of Ozone

The basic laws of gas solubility in liquid s a re H enry's a nd Dalton 's law. Henr y's law states th at the weight of a gas that will di ssolve in a give n vo lume of liquid is directl y proportional to the partial press ure of that gas in contact with the liquid .... Dalton' s law states that in a mixture of ideal gases eac h gas exerts th e partial pressure that it would if separate, i. e. pa rtial press ures are additive .. •. Therefore the concentrat ion of gas C, in co ntact with a mixture whi ch contains a partial pressure of gas p, is given by C, = Hp, Where H is a Henry's law constant. For oxygen in air at atmospheric press ure p, wo uld be 0. 2 1 of a n a tmosphere for pure oxygen it wou ld be 1.0 at mos pheres. The value of H vari es with tempera ture, solubilit y decreases with a n increase in temperature. Di fferent gases have different va lu es of H (at constant tempera ture) so lub le gases such as chlorine a nd ca rbo n dio xide have hi gh values of H whil e oxygen a nd nitroge n have small H values. O zone is more soluble t han oxygen but is still not highly soluble. For exa mple at 0°C, air wit h 2 111/o oxygen conta in s 299mg 0, / L air a nd 14 .6mg 0, are soluble in a litre of water. Ozonated air whi ch co ntain s 111/o by weight o f ozone contains 12.9mg 0,/L of air a nd 8.3 mg 0, a re soluble in a litre of water•. Thus ozone is approx im a tely 13 times more soluble than oxygen, to ac hieve I mg/ L of ozone in water the gas concentrat ion must be 1.6mg 0, / L air whi le to achieve lmg/ L of ox ygen requires 20mg 0 2 / L air' . The diffi culty with ozon e is to achi eve significa nt ozone concent ra ti ons in the gas phase at a n eco nomic rate. Several methods are availa ble to dissolve ozone in water'·' a nd high (>8011/o) solution efficiencies can be achieved.

Inact ivation of poliom ye liti s virus has received fl'le most attention, confirming the hig h act ivit y of ozon e, for example to achi eve disinfection ', 0.05mg/ L of ozone, 0.08mg/ L of ch lor ine dioxide and 2.25mg/ L of chlorine have been suggested. Th e innuence of contact tim e a nd ozone dose on the surviva l of po!iovi ru s 1 is ill ustrated in Fi gure 2. For 9911/o inactivation thi s can be ex pressed 10 by t he empiri cal equa ti o n C' ·' t99 = 0.44 Wh ere C = co ncentration of ozone t,, = contact time for 9911/o inac ti vation. Again indicating a strong dependence on ozo ne conce ntra tion as opposed to co ntact time ". A more theoreti ca l approach to the inacti vation ki netics indi cated 10 that the inacti va tion co uld be described by dN = _ k C No.,9 dt Where N = viral n umbers k = consta nt. The activation energy of the reaction is low (3.6kca l) suggestin g that th e reaction is contro lled by the mass tran sfer of ozone through the protein coat of th e virus 10 • The ozone once insid e the protein coat breaks down the RNA structure of the virus 1°. T he inactivation of poliomyelitis vi ru s was not inhibited in the prese nce of turbidity du e to alum noes " in th e turbidi ty ran ge of 1-5 T. U. Simi lar results were obse rved for coxsac hi ev iru s A9 and Escherich ia coli. T he innu ence of organic turbidit y has not been reported 1•. It ca n be concluded t hat on th e ava ilab le ev idence o zone is a n effective di sinfecta nt o ve r a wide concentration ra nge a nd tha t the co ncentration of ozone is more crit ica l than the co nt act time in determining survival rates . No reference was found to the effects of ozone o n amoeba. 2.4 By-products and End-products

Ozo ne with orga nic material can fo rm little ch loroform because the o nly available chlo rin e a tom s are those in the organic ma terial. This has been con firm ed ex per im entall y". in di stilled water to whi ch was added !0mg/ L of humic ac id a nd !0m g/ L of ozone on ly 0 .6 /Lg/ L of chl orofor m co uld be detected. However ozone is a su ffic iently powerfu l ox ida nt to convert bromide to bromine a nd this ca n lead to the formation of brominated trih a lomet hanes. In ,th e presence of !Omg/ L of humic ac id, 10mg/ L of bromide ion s and 10mg/ L of ozon e 153.7 /Lg/ L of bromoform were detected " . Orga ni c mol ecul es can be degraded by o zone to carbon dioxide a nd water, however unless ozo ne is prese nt in a large excess some intermediates will be produced . For example p~enol is ox idi sed by ozone to orthodihydroxy benze ne and ortho benzoquinone. Further oxidation produces decarboxy li c ac id s of decreasin g cha in lengt h (C4 H, (COOH),, C, H, (COOH), , (COOH),), the malaeic and oxalic acids 100

10 0

> >

2.3 Kill Rate

The effect of ozone of Escherichia coli was reported ' to change with concentration . Effective bacteriocidal actio n was possible a t high concentratio ns whil e at low co ncentrations ( < 0.4mg/ L) ozone was a rela tively weak reagen t. By con trast chlorine maintain s its activity a t low concentrati ons. More rece nt studies• have indica ted that there is a linear depend ence of log tota l or faeca l coli for m reduction a nd log absorbed ozo ne dose . These later experim ents carefu lly measured the ozone utili zed and obtain a high degree of co rrela tion (r ' = 0.97). The coliform reduction was independent o f contact time . Hence for co liforms it would appea r that ozo ne is a strong bacteriac ide over a wide concentration range• . There have been several studies of the inactivation of viruses by ozone. In all cases '· " hi gh rates of in act ivat ion ( > 9911/o) were obse rved at low doses ( < I mg/ L) a nd short contact times ( < 5min) .

::,

....C Cl,

~ Cl,

0 ·1

0·01 L - - -- - - - - L - - - - - - -- - ' - - - - 50 100 Contact

t i me

Figure 2. Influence of ozone residual on survival of Poliovirus 1 at 20° , pH 7.2 (after ref. 10). WATER September, 1983

10 3 ...J

.., C

:::, 0

10 2

..,a; u

0 aJ

1() I

10°~---~~-----~----~----~ 200 Time - hours 0 400 Figure 3. Bacterial regrowth in seeded Lake Constance water (after ref. 15). can be oxidised to carbon dioxide and water' 6 · " . T he ozone requirement for phenol oxidation increases as the pheno l concentration is red uced, at low concentrations high doses of ozo ne relative to phenol ( > 3: 1) appear to be required . T he oxidation of organic material is likely to produce some partially oxidised products such as benzoquinones, the health effects of which are uncertain 15 • T he low molecular we ight products will be more biodegradeable than the initial organ ic material present prior to ozonation hence the growth of bacteria in ozonated water without a supplementary residual will be significant. Experiments carried out on water from Lake Constance •• showed that seeded water after ozonation was a much better growth media than non ozonated water, Figure 3. T he use of an auxi li ary disinfectant such as chlorine or ch loramines to provide a stable residual after ozonation for disinfection and organic degradation has clear advantages. Care has to be taken that sufficient ozone is added to degrade the organic material sufficiently to prevent subsequent organo ch lorine production". For example, pretreating a water which contained 20mg/ L of humic acid with ozone followed by 20mg/ L of ch lorine still produced some organo chlorine compounds. After 5 hours total contact without ozone pretreatment there was approximately 15 µg / L; with 0.6mg 0,/ mg C, 1100 µg / L; with 2.5mg 0,/mg C, 300 µg / L a nd with 8.6mg 0,/mgC 200 µg / L. Hence provided suffi cient ozone is used to substantially oxidise the humic acids relatively little ch lorinated organics will be produced . In general the products from ozonation will be of higher taste and odo ur threshold than for chlorine, clearly chlorinated phenols wi ll not form. T he end product from ozone is oxygen, the ozone breaks down in a few minutes leaving no effective residu al. 2.5 Ozone Summary Ozone is a good disinfectant against both bacteria and viruses. It will only produce trih alometh anes in the presence of bromides and the organic residues have not been implicated as a health hazard (yet!?). T here is no residual disin fectant action of ozone and the partially degraded organic residues can be a good bacterial growth media .

method of generatio n is by acid treatment of sodiuli) chlorite 1•. 5Na ClO, + 5HC l s=e 4Cl0, + 5NaCI + HCI + 2H,0 This gives a theoretical yield of 0.8 moles C l0 2 / mole of chlorite, with hydrochloric acid yields of this type are produced, with sulphuric acid the yield is closer to 0.6 moles C 10,/ mole of chlorite, which suggests a significant role for the chl oride ions in the reaction". T hi s production method will generate ch lor in e dioxide with little or no ch lorine contam ination . In the U.S.A. the gas is a lso prod uced from solium chlorite and chlorine for a 1: l molar yield . 2NaClO, + C l , s=e 2CI0, + 2NaC I Considerable care and control is required to prevent contami nation of the ch lorine dioxide wit h chlorine wh ile maintaining reasonable yields. T his may be required if chlori nated by-products are to be avoided during disinfection. Chlorine dioxide can be produced from solium ch lorite, sulphuric acid and hypochlorite ions . In the pulp and paper industry solium chlorate and acid are used. NaClO, + NaC l + H,so • .,. ClO, + 1c1, + H ,0 This route is more economic for large quantities (>tonne/ ct) but will always yield a mixture of chlorine dioxide a nd chlorine and is not reported for water treatment practice" . 3.2 Kill Rate Chl orine dioxide has been shown to be a more effect ive disinfectant than chlorine. The dose required to inactivate poliomyelitis virus is significantly less than that for chlorine' ·8 · 20 · " · " . T he survival of co li for ms is less effective in the presence of chlorine dioxide when compared with chlorine, Figure 4. The product of res idu al and time for ch lorine dioxide was always less for a given percentage kill than for chlorine'"·" . The overall kinetics of the bacterial destruction appear to be similar for chlorine and ch lorine dioxide' ". Chlorine dioxide maintains its disinfecting action over a wide pH range including high pH va lu es and is not subj ect to interference by ammonia and amino compou nds. 3.3 By-products and End-products

Chlorine dioxide forms only very small concentrations of tri halomethanes. For example 10mg/ L of humic acid and 10mg/ L of ch lorine dioxide only produced 0.2 µg / L of tri halomethanes, in a similar experiment with 10mg/ L of chlorine ;222.4 µg / L of trihalomethanes were produced 15 • This result has been confirmed in studies of the disinfection of nitrified effluents in wh ich doses of 20 and 40mg/ L of chlorine dioxide produced insignificant yields of both trihalomethanes and other halogenated organics••. By-products similar to those referred to frfr ozone (section 2.4) produced by partial oxidation, such as quinones, may be produced and their effects are not yet estab lished.

z z

010

3. CHLORINE DIOXIDE

There were reported' to be 84 plants in U.S .A. and 500 plants in Europe using chlorine dioxide (CIO,) as a disinfectant for water supplies. The major applicat ions appear to be for the control of tastes and odours, more recentl y chlorine dioxide has been used to reduce trihalomethane concentrations. 3.1 Generation Chlorine dioxide is a reactive gas which has to be generated on site and cannot be eas ily stored or transported. In Europe the major 14

WATER September, /983

> >

;; 10-'

<fl

Residual

10 1 10 2 time mg . min ./L

Figure 4. Survi val ratio of coliforms and chlorine a nd chlorine dioxide (laboratory studies) (after ref. 18).

The end products from the use of chlorine dioxide will include, chloride ions c1-, chlorite ions CIO,, chlorate ion s C l0, and residual chlorine dioxide CIO,. The oxidising residuals have been found to interfere with th e fun ction of the blood, oxidising haemoglobin and reducing oxygen transfer. The E.P .A. (U.S.) has recommended that the oxidant residuals (CIO,, CIO;, CIO;) should not exceed 0.5mg/ L, while other co untries restr ict chl orite concentrations (Norway Omg/ L, West Germany <0.3 mg/ L, U.S.S.R. <0.4mg/ L). The exact mechani sms for the ionic oxidant residual production has not been estab lished so prediction of these residuals is difficu lt. 3.4 Chlorine Dioxide Summary Chlorine dioxide is a powerful di sinfectant over a wide pH range which provides a stable res idual. There is no chl oram ine produ ction nor are trihalomethanes form ed . The production of chlorinated products is small although there is a small yield of chloroph enols, quinone and hydroquinone type of molecule. The oxidative endproducts a re considered to be a health risk and have to be controlled. Chlorine dioxide disinfection can be retrofitted to existing plants without major restructuring. 4. ULTRAVIOLET IRRADIATION

Ultraviolet li ght will disrupt the chemical bonds of many organic mo lec ul es a nd hence is a potent disinfectant , ultrav iolet light (uv) is considered to be absorbed by the DN A of cell s, particularly to produce thymine dimers" ·24 • The distorted DNA res ults in the death or mutation of the cell or production of non viab le offspring. As with other disinfecta nts it is necessary to defin e the dose, kinetics, cos t and side effects of u. v. irradi ation. The major applicat io ns have been to provide high purity process feed water in specific industries, eg. pharmaceutical and sem i-conductor manufacture and medical appliaction s. 4. I Ultravoilet Technology

Ultraviolet light can be generated fro m low pressure mercury lamps24 · 25 • In conventiona l u.v. disinfection systems the lamps are surrounded by a cylindrical sleeve of quartz, this being one of th e few materi als transparent to u . v. light. Water flo ws over a bank of quartz sleeves in a si milar manner to the shell side flo w of a shell and tube heat exchanger. In all bu t the cleanest of waters there wi ll be an accumulation of materials on the quartz sleeves which interferes with the irradiation of the water. Therefore it is necessary to have so me means of ensuring a clean outer sur face of the quartz sleeves. A mechani cal wiper system can be used 24 whi ch periodically scrapes away fouling. For this to be effective a high degree of engi neeri ng precis ion and reliability is needed , such a system has been reported in fu ll sca le operation 24 • Alternatively ultrasonic cl eaning can be used but to date has not been applied in full scale plants. Systems based upon a teflon piping system are availab le" . Teflon tran smits u . v. light and is stable under irrad iation . The water to be disinfected in passed thro ugh a teflon tube which is ex posed to irradiat ion from u .v. lamps. The teflon tubes can be arra nged to provide a serpentine flow of water and the u . v. intensity enha nced by incorporating a luminium reflectors in the system. T hi s system gives good exposure to the radiation while teflon is chemically inert and non wetting so fou ling is minimi zed". 4.2 Ultraviolet Dose A published compilation" gives the u. v. dosage necessary to inhibit colony formation for micro-organisms . For Escherichia coli this is reported as 6,600 µ.W / cm' and the majority of bacteria are within the range 2,500-22,000 µ.W /cm', common viruses such as the influenza virus are inactivated at a si milar dosage. The range of dosage for fungi and algae is wider, ll ,000-33 0,000 µ.W / cms'. The suggested irradiation for disinfection 24 • 25 is 16,000-25, 000 µ.W /cm'. The actual dose of u .v. light received by any mi cro-organ ism in either a quartz or teflon system will depend upon the proximity of that micro-organism to a u.v. lamp . Hence to calculate the dose requires a consideration of the configuration of lamps a nd water flo w and the properties of th e water. The exposure time to u .v. light , assuming no short circuiting or back mi xing will be given by24 •

Exposure time t =

Where V., void volume Q = flow m' / s

The lamps used for irradiation can be defin ed'; for example 24 the incident intensity I, from a lamp of 1000 cm' surface area and 30W o utput would be theoretica lly 30000µ.W / cm', a 10% loss is lik ely hence 27000µ.W / cm'. The intens ity of th e light will decrease with th e distance from the lamp, hence ass uming no absorption of light in the solution the intensity I at a di stance x from a lamp of radius r will be:

I = I, r + x In fact the water will absorb some radiation and this can be defined by Beers law as I = I, e-ax Where a is a Beers law constant. Therefore the intensity of light at a given point will be 24 I = I _ r_ e-ax 0

r +

By making reasonable assumpti ons abo ut the value of a (usually within the range of 0.2-0.5 cm-•), the u. v. intensity within a u .v. lamp/ water co nfiguration can be mapped . The average intens ity is lik ely to be grea ter than the output intensity of a single lamp because the lamps wi ll be sufficiently close to increase the overa ll rad iation. For example for one configuration for lamps of incident intensity 27000µ.W / cm' the average intensity was 48000µ.W / cm'. Provided that the flow through the system is turbulent and does not short circuit it can be anticipated that this average intensity of irradiation will be experienced by all of the micro-organisms in the water.

4.3 Kill Rate

At high concentration s of micro-organism uv irradiat ion appears to give a fi rst order linear kill rate 24 however at lo w micro-orga ni sm numbers the dependence is non linear. Disinfection mu st occur at low micro-o rganism numbers and a better fit to the expe rimental data has been observed for a second order dependence . dN = - k N' I dt Where N is the number of micro-organism s I is th e u .v. intensity. This integrates to _!_ _ ~=k i t

The initia l number of mi cro-organisms N , is much greater than the number after co ntact tim e t , Hence

1. » 1. N

1. =

k It

N The survival of coliform bacter ia has been found to be a lin ear function of the product of u .v. intensity and cont act tim e 24 (Figure 5) .

4.4 U ltraviolet Irradiation Summary

Ultraviolet irradiation can act as a powerful disinfect ing agent. In order to understand and optimise the sys tem it is necessary to understand the flow regimes through a u.v . cell a nd th e light intensity to which micro-o rga ni sms are exposed. There is little available data on the by-products of u .v. disinfection. The method leaves no residual to kill micro-organisms in the distribution system and may produce some organic or inorganic by- products due to chemical reactions induced by radiation . It is necessary to maintain a u.v . system to ensure continued effective disinfect ing action. This will involve replacement of u .v. lamps (perhaps every year 24 ) and preventive actions to ensure th at the light and flow patterns are not impeded .

5. COSTS

Clearly it is difficult to make meaningfu l cost compa risons between chlorine and alternative di sinfectants beca use there are no alternative disinfectants in large sca le use in Australia. Costing information is available from North America and E urope , the former sources have been used in thi s paper. The relevance of such information again can only serve as a guid e, there are several variables which may di stort the direct translation of the quoted fi gures to local practice - these include WATER September, 1983

,o 5

TABLE 1: COSTS OF DISINFECTION Planr size flowrarem.g.d.

..J,04

Cosrs", cenrs/ 1,000 gall. (U.S.)

Chlorine 2mg/ L

E 0

I IO

100 150

3.25 1.08 0 .58 0.5 5

Ozone I mg/ L Air Oxygen 5.65 1. 88 1.1 6 I. II

7.33 1.96 I. I 3 1. 07

Chlorine dioxide I mg/ L 3.45 1. 63 1. 25 1.22

1/l

6. CONCLUS IO NS

10 1

500

100

Uv dose 10 3 µ. W s/ c m

Figure S. Co liform survival as a function of uv dose (after ref. 24).

•

T he interest rat es from sources more than 12 mo nth s o ld will tend to be significantl y lower than those curren tly available. As the cost of these systems includes between 20 a nd 50% for a morti zed cap ital costs' ·" ·" the data is very sensiti ve to interest rates. Interest rates of a pproximately 8% have bee n in much of t he repo rted data. • Supplies of both equipm ent and chemica ls are more restrict ed in Australia. For example sodium chlorite is not loca lly manufactured so will be expensive un less t here is a large loca l use of chlorine dioxide . • The economic co mpa ri so n of systems of d isin fect ion must account for the required doses to achieve a specifi c water qua li ty. The response of all waters will differ in t he disinfectant requirements, while in genera l the concentration of ozone a nd th e chlor ine dioxide will be less than that of chlorine the actual ratios will be dependent upon th e characteristics of the water . • Energy costs have in creased recently a nd represent a variab le proportion of each total di sinfecta nt cost. For t he purpose of thi s paper publi shed costing data is presented without attempting to recalculate on a local or current bas is. T he fi gures should on ly be taken as a guid e for the basis of qualitat ive compariso n . A published compa ri son of U.S. costs is given in Tab le I for chlorine, ozone a nd chlorine dioxide a t doses of 2mg/L, lmg/L a nd lmg/L. The data 2• quotes costs in USc/ 1000 U.S . gallons (approximately USc/ 4m') for vario us sizes of plants, again lm .g. d . represents approximately 4000m'/d . For each water treated the di sin fect ion doses and their rati os will be different. In all cases chlorine is the cheapest disinfectant. For small plants chlorine d ioxide is comparable, but for the majority of cases alternat ive disinfecta nts a re 2-3 ti mes th e cost of chlorine. Quoted costs for u. v. irradiation 24 indicate that for treatin g flo ws of 1- 100 m .g .d. th e costs ra nge from 4-2 .7c/l 000 gall on s (U.S.), again the costs a re co mpa ra bl e for t he small size of pla nt but more expensive for large plants (C l ,, range 3.25-0. 58 c/1 000 ga ll ons (U .S.)). Again it shou ld be stressed that these figure s ca n only act as a guide. T he use of supplementa ry processes such as superchlorination/ dechlor in a tion or precurser remova l with acti vated carbon and separate residu a l disin fection for example with ozone may have to be considered . Th e influ ence of water cha racteristics a nd loca l factors such as chemi ca l cos ts will furth er d istort th e figures, for example generation of chlorine dioxide may req uire the supply of bulk chemicals cost ing ten tim es those for chlorin e. Seaso nal use of alternatives to ch lo rin e, to co unteract spec ifi c problems such as reservo ir overt urn , or mi cro bia l grow ths again ca n infl uence overall costs. 16

WATER September, 1983

It is not feasible to suggest that a ny single di sin fecta nt has un iversal mer it, on ly general conclus ion s can be drawn. • Ozone is the mos t act ive disinfectant , fo ll owed by c lor ine dioxide a nd chlorine . Ultrav io let irradiation has simil ar act ivity but will depend upon the applied irradiation. • All of the chemica l disinfectants produce some by-products or end -prod ucts which represe nt a hea lth ri sk or are improve n. Ch lor ine produces chlor inated orga ni cs in cl uding trih a lomet ha nes, chlorine di ox ide does not produce chlo rinated o rganics (to a sign ifica nt extent) but the oxidat ive end -products (CIO,, C lO,, Cl0 2) have been implicated, ozo ne on ly prod uces tr ih alo metha nes in the presence of brom ide ions and both ozo ne and chlorine dioxide prod uce some pa rti al ox idation products which are bein g investigated. • Ch lori ne and chlorine diox ide provide a stable res idual, ozone a nd u. v. irradiation do not prov ide a res idu al. • Chlorin e is the cheapest di sin fectant however fo r small plants ( < 5ML/d) u. v. irrad ia tion a nd chlorine d ioxide may be compara ble. For a ny water treatment plant it will be necessary to eva lu ate th e relative merits of each di sinfectant for loca l use. It shou ld be stated that as with all Public H ealth Engineering projects a com plete evalua tion of the treat ment systems is req uired. Optimisation of onl y one uni t process , in th is case disinfectio n , may be to the detriment of the overall system . Over reliance upo n disin fect io n for pathogen remova l can be a short sighted evaluation of water treatment. By improving the effec ti veness of other unit processes such as aerati o n , filt ration, storage and coagula ti o n the im porta nce of factor s such as organo chlorine compoind formation can be less sign ifi ca nt.

7. REFERENCES I. D. Barnes, P. J. Bliss, B. W. Go uld, H . R. Vallentine. 'Water and Wastewater Engi neering Systems' Pitmans, London , Me lbourne , Marshfie ld, I 98 I. 2. G. W. Mi ller er al. An assessment of ozone and chlorine diox ide tech no logies fo r treat ment of mu ni cipal wate r suppl ies, E.P.A. 600/ 2-78- 147, U.S .E .P.A. C incinn a ti , 1978. 3. K. L . Rack ness er al. Case history: ozone disinfecti on of was tewater with an air/ ozone system , in Proc. Wastewater Disinfect io n A lte rnati ves - State-ofthe-Art Workshop, W.P.C.F. Conf. Houston , 106- 137, 1979. 4. A. D. Venosa a nd E . J. Opatken. Ozone disinfectio n - State-of-th e-Art, ibid 7 1- 105. . 5. S. Sheffer and G. L . Esterson . Mass transfer and reaction kin etics in the ozone/ ta p water system Water Research 16, 383-389, I 982. 6. R. M. Fetner a nd R. S. lngo ls. A comparison of the bactericidal activity of ozone a nd chlorine against Eschi. coli at 1° c J. Gen. Microbial 15, 38 1-387, 1956. 7. 0. Hettche and H . W. S. Ehl beck. Edidemio logy and Proph ylaxis of poliom ye lit is with reference to the role of water in its tra nsmission . Arch. Hyg. Berl. , 137, No. 440, 1953. 8. F. L. Eva ns. Ozone Techn o logy - Current Stat us in O zo ne in Wate r and Waste water Treatment , F. L. Eva ns, Ed ., An n A rbor Sci., Ann Arbor, Mich. , 1972. 9. L. M. Ev iso n. Inact iva tion of ent eroviruses and coliphages with ozone in water a nd was tewaters Prog. Water Tech. IO, 368-378, 1978. 10. D. Ro y, E . S. K. Chia n and R. S. Engelbrecht. Kinetics of ent erov iral inactiva ti on by ozone Proc. Am. Soc. Civ. Eng ., J. Envir. Eng. Div., 107, 887-90 I , I 98 I. 11. D . S . Wa lsh , C. E. Buck and 0 . J. Sprou l. Ozone in acti vat ion of noc associa ted viruses and bacteria, ibid 106 , 7 11 -726, 1980.

Continued on page 21

Water Quality Factors in Inland Waters An Overview-Lake Eppalock W. M. Drew INTRODUCTIO

As a consequence of its role as a water resource management agency, the State Ri vers a nd Water Supply Com miss ion (the Water Commission) carries out catchment and water quality studies on many of its larger reservoirs in order to assist in developing suitab le management strategies. A recent in tensive study on Lake Eppa lock and its catchment is discussed as an example of the Co mmiss ion's work. Lake Eppa lock as a Water Supp ly Source

Lake Eppalock is a supplementary so urce of the Caliban Water Supply System which supp li es the city of Bendigo. In addition to augment ing the supply to the Bend igo Urban Complex it for ms part of the water supp ly system to sma ller towns as well as being used for irri gation in the Coliban System, and via the Campaspe Ri ver, in the Campaspe Irrigation District near Rochester. The reservoir was completed in 1963 for the specific purposes of: • safeguarding the supply of the Coliban water supply system; • perm itting increased development in urban areas, includ ing the Bendigo ubgan complex and other towns; • maintaining the rural suppl y within the Caliban system; • providing irrigation water to the Campaspe Irrigation District; • securing supplies to diverters a long the Campaspe River down stream of the dam .

to the system via a 900 mm diameter pipeline to the No. 7 and Spring Gully Reservoirs. At these points Eppalock water mixes with water from the Cal iban Reservoirs, to give a composite water quality as show n in Table I . The water quality is, on average, very good and except for co lo ur, turbidity and iron, complies wit h th e "Long Term Objectives" specified in the Austra lian Water Quality Guide lin es (NH & MRC I 980). In general, the average quality meets the "Desirable Current Criteria" as specified in the sa me guidelines, except for iron .

It is thi s qua lit y the Commission wishes to preserve. Any reduction to unacceptab le quality leve ls (specifica ll y for co lour, turbidity and iron) cou ld require expe nsive water treatment facilities to meet Bendigo's needs, additiona l to the $ 10 million (approximately) being spent on the Sandhurst reservoir and the Eppalock pipeline ($3.9 million, incl uding a proportionate share of the reserv ior cost). Some of the Eppa lock catchm ent factors

THE COLIBAN SYSTEM AND WATER QUALITY A schematic representation of how Eppalock lin ks into the Caliban water supply system is given in Figure 1. The major point to note about the Bendigo Urban supply is that Eppa lock is co nnected

Dr. W. M. Drew is Chief, Water and Materials Science Division of the Slate Rivers and Water Supply Commission, Victoria. This paper was first presented at a Vic1orian Branch Conference, Bendigo, Oc1ober 1982.

THE 1980/ 81 CATCHMENT AND WATER QUALITY MONITORING PROGRAMME

Previo us studies (i.e . prior to the 1980/ 8 1 programme) achieved:

SYSTEM DEMANDS Bendigo Urban

Coliban Irrigation

Reservior stat istics

The vital stati stics of the storage are: Capacity 312,000 megali tres Surface Area (full) 3,237 hectares Shoreline 153 km Maximum Depth 39.6 m Average Depth 9.6 m Embankment Height 45 .1 m Lengt h 700 m Outlet tower: Number of outlets 7 Location of outlets 2 near FSL 2 mid depth 3 near bottom

affecting water quality in the reservoir wi ll be discussed, the so urce being the Report by the Int er-depart menta l Com mittee (!DC) o n Lake Eppalock, June 1981. The !DC was formed in March I 980 to " . .. establish guide li nes for development for Lake Eppalock and its environs cons istent wit h water qua li ty requirements from the lake". This work followed two previous studi es (Coulthard 1976 a d Water Comm ission 1979) and took into account previous monitoring programm es and data collected. The Committee also comm iss ioned a water qualit y stud y (1980/ 8 1) to provide it with additional data regarding specif ic s ub catchment run -off qua lit y, recreational effects, lake quality and major input stream quality.

Bendigo Reservoirs Specimen Hill Crusoe No.7 Reservoir Sp ring Gully

Releases Via Campaspe River to Ca mpaspe Weir for Irrigation (near Rochester)

Strathfieldsaye Eppolock Pipeline

Compospe River Diverters

Eppdlock Reservoir

I _l

Sandhurst 1 1 ~nder conss

Caliban Main Channel

Costlemo ine and small towns

Caliban River Compaspe Inflows Wild Duck & Other Creek Inflows

Caliban Reservoir Mal ms bury Louriston Upper Cal iban

Coliban Inflows Figure 1. Sc hematic of the Coliban Water Supply System . WATER September, /983

TABLE 1: SUMMARY OF MAIN PHYSICAL AND CHEMICAL CHARACTERISTICS AT COLIBAN SUPPLY HEADWORKS AND NO. 7 RESERVOIR 1973-1980t Characteristic (all units mg/ L) unless stated)

Eppalock Res.

pH units TDS Colour (Pt. Co Units) Turbidity (NTU) Hardness Alkalinity Chloride Calcium Magnesium Sodium Sulphate Fluoride Iron Manganese

Malmsbury Res.

No. 7 Res.

•Australian Guidelines

min .

mean

max.

min.

mean

max.

min.

mean

max.

Desirable Current Criteria

Long Term Objectives

7.2 169 60 2 67 48 48 IO 9 3I 2

7.6 339 105 8.3 72

8.1 405 160 22 175 96 140 18 32 76 67

4.7 74 30 4 22 22 20 2. 1 4.0 12

7.4 97 60 13 44 35 26 6.9

8.4 324 150 30 121 86 44 9.2 16.0 21 42 .17 2.2

6.8 79 20 2 31 25 22 4.2 3.0 12 <I < 0.02 < 0.1 N.D.

7.5 108

9.2 340 140 30 83 82 68 11.0 15.0 46 25 .22 1.9 0.04

6.5-9.2 1500

7.0-8.5

56 5I 13 IO 37 27

.32 N.D.

1.2

2.3 0. 83

.02 .04

6.5 16 8 .06 1. 2 0

50 6 63 37 36 8.1 10.0 18 4.7 .07 I. I 0.02

500 5

25 600

100

600 200 150

200 75 30

400

200

1.0

0.5

0.1 0.05

• Com monwealth Depanment of Health. Nationa l Health and Medical Research Council, Au stralian Water Resources Council, 1980.

N.D. - not detected

Based on monthl y sampling programme.

• · A good understanding of lake chemistry

Tota l Manganese (Mn)

and dynamics • An indication through bacteriological monitoring of problems associated with foreshore practices. However , more information was required to enable more accurate predictions to be made regarding such potential influences as: • Periodic recreational activity • Genera l foreshore development • Land form features of the catchment • Townships within the catchment • Genera l land-use factors (e. g. Agricu lture and Forestry) in the wider catchment. Consequently, a comprehensive pro gramme was arranged to run through 1980 to early I 98 I as fo llows:

Escherichia coli (E. coli)

Periods Covered-1980/81 Bacteriological sampling (E. coli)

Labour Day week-end (8th-10th March I 980), lake on ly. Easter (4th-8th April I 980), lake plus input streams. Comprehensive Survey (including E. coli)

18th June up to 28th January 1981 (fortnight ly). Including the major holiday periods Christmas 1980 New Year 1981 Australi a Day week-end 198 l. The scope of the 1980/ 81 survey was: • Lake • Lake foreshore • Water catchment • Perimeter lessee supplies. The sampling points are shown in Figure 2. A tota l of 30 sampling sites were monitored in the catchment including the outlet from Lake Eppalock as part of the study. An additional seven lake side points were monitored near club sites. The water quality parameters measured wit hin the 1980/ 81 comprehensive survey included: Total Dissolved Salts (TDS) Suspended Solids (SS) Turbidity (NTU) Colour Total Iron (Fe) 18

WATER Seprember, 1983

Total Phosphorus (Tot-P) Nitrate + Nitrite (NO,· + NO,·) Ammonia (NH 3) Total Kjeldahl Nitrogen (TKN) Reactive Silica (SiO,) Total Organic Carbon (TOC) Total Lead (Pb) Cadmium (Cd) Copper (Cu) SUMMARY OF MONITORING RESULTS

Owing to the a mount of information collected (i.e. from 1963) only a brief overview can be given of the major findin gs which have emerged from an analysis of all data co llected, including the 1980/ 81 programme. Brief outlines of recreat ional activity and catchment factors are given for completeness.

shore zone as visitors create new tracks and parking areas. Further, since most caravan sites are let on an annual basis, people see king casual sites for one or two nights are often turned away and thus sometimes attempt to park in unauthorised areas. The Committees of Management have given consideration to improving public facilities including traffic control and roadworks, however, the Interdepartmental Committee 's view is that whilst this should be encouraged, care should be taken not to distract too many additional visitors, since in the I 980/ 81 studies, run-offs from monitored club sites have shown high faeca l bacterial levels (270,000/ 100 mL) combined with high suspended solids levels. At the moment this run-off is assimilated within the lake but the Committee believes that any 's ignificant' increase in recreation activity cou ld be harmful to water quality.

Recreation

Since its completion, Lake Eppalock has developed into one of the most popular inland water bodies for recreation in Victoria. Caravan park s, clubs and commercial establishments can provide overnight accommodation for 6,755 people. In addition, records show that up to 12,000 people per day have visisted the area during peak holid ay periods over Christmas, Australia Day and Easter. Some levelling off of the use of the lake and its surrounds has occurred in recent years with the estimated number of vehicles visiting the Kimbolton Com mittee controlled public areas decreasing from 12,800 in I 974/75 to 3,980 in 1979/ 80. Further, the number of power boats using the lake has decreased from 1,400 in January 1978 to 1,010 in January 1980. Notwithstanding this levelling off, the impact of recreation has continued to be significant, although the sep tic tank effluent from all caravan parks, public toi let blocks and most club sites has been connected to disposal systems which convey the effl uent to evaporation lagoo ns located away from the lake. The impact of the large number of visitors to the area shows up in disturbance to the fore-

Catchment Characteristics

The total area of the Eppalock catchment is 2, 124 square ki lometres, including 290 square kilometres comprising the catchment of the Coliban River storages at Malmsb ury, Lauriston and Upper Coliban. Only about 15 per cent of the total area remains forested . The remainder of the catchment is used for grazing, mainly sheep, some small areas for cropping and about one per cent is developed for urban purposes. So ils in the area are genera lly acidic and of low fertility, excep t where they overlay basalt , in which case they have moderate to high ferti li ty. About 40 per cent of the catchment base rocks are Ordovician, sedimentary slates and sa ndstones, and these areas have historicall y displayed extensive gullying and sheet erosion. Climate in the catchment varies from South to North. In the South the climate is predominantly humid , whilst in the North it tends to have cool, moist winters with very hot , dry summers. Average annual rainfall from South to North varies from 1,120 mm to 540 mm. Mean annual temperatures also increase from 10°C to 12.5 °C.

Lake Eppalock

VICTORIA

5 10 15 km

Air Valve 23 Lakeshore Caravan Park Gunn's Paddock Oerrinal Pool Subdivision

KBM Camp

Ferntree Gully Technical School Camp Richmond Technical School Camp Wild Duck Creek

Metcalfe Housing CO- OP

• Bacteriological Sampling Sites Coli ban River

Campaspe River

Limnological Sampling Sites

5km

I II II I Figure 2. Lake Eppalock sampling sites .

WATER Septem ber, 1983

TABLE 2: CONCENTRATIONS AND LOADS OF KEY WATER CONSTITUENTS IN MAJOR LAKE EPPALOCK INFLOWS (from IDC Report on Lake Eppalock (1981)) Inflow Stream / Flow Condition

Co nstituent Concen tration / Load Suspended Solids (S.S.)

E. coli E.C.

kg/ day

mg/ L

kg/ day

22 880 2300

5720 3150400 1560000

1150 474 3 10

17940 IOI 185 126480

0.24 1.95 3.76

6 698 2557

912 9984 39360

80 900 1300

60800 3455600 12480000

1180 720 340

538 10 165890 195840

1.0 2.43 3.68

76 933 3533

5 13 14

50 2964 3500

26 790 710

2600 1801200 1775000

2400 700 510

14400 95760 76500

0.21 1.71 2.32

2 390 580

2 15 16

66 2760 2256

70 1300 1700

23 100 2392000 2538000

2320 455 370

45936 50232 31302

1.51 2.48

278 350

Load kg/ day

Orgl 100 ml

< I 21 30

<26 75 18 20400

Coliban Ri ve r at Lyal-Site 16 Low Flow 76 ML/d Medium Flow - 384 ML/ d High Flow - 960 ML/d

12 26 41

Wild Duck Creek at Langworne r-Site 7 Low Flow 10 ML/ct• Medium Flow - 228 ML/d High Flow - 250 ML/d* Mt. Ida C reek at Derrinal-Site 5 Low Flow 33 ML/d Medium Flow - 184 ML/d High Flow - 141 ML/d

Low flow reco rd ed on 18 June, 1980. Medium flow recorded on 29/ 301h Jul y, 1980. Hi gh fl ow recorded o n 22/23 Augu st, 1980.

Fluctuating annual stream flow s are a feature of the area and historical hydrological data have indicated that between I 894 and 1948 the area experienced a number of dry periods extending over several years. Long dry periods fo ll owed by drought breaking rains have marked effects on water quality, particularly in respect to suspended solids concentrations (JDC Report on Lake Eppalock [1981]). No such extend ed dry periods have occurred (except for this year) over the catchment si nce the reservoir was built. Some of the conclusions of the study may need reassess ment in the light of what occurs as a result of the current dry situation . Soil sa linity problems are seen to become worse from South to North in the catchment. Comments on Specific Water Quality Findings

The parameters of major concern were suspended solids (turbidity), £. coli, total salts and iron. Table 2 gives a summary of the major findings for input streams in terms of concen tration s and loads for these parameters. A brief discussion of each follows: Suspended Solid s (and Turbidity)

The level of suspended so lids (and hence turbidity) in stream s responds markedly to st ream flow due to greater turbulence and transport energy associated with high flows. The increased turbulence provides an increased abi lity for the streams to keep particulate matter in suspension (see Table 2). During the I 980/ 81 survey the turbidity levels in the lak e remained low, the maximum recorded was 8. 7 NTU in July I 980. However, in I 973 and I 974 inflows were high and the turbidity at the outlet tower reached 22 NTU and maintained a level close to 14 NTU durin g 19 75 and 1976 before diminishing to about 4 NTU during 1977 and 1978. This respon se is believed to support the view that lake turbidity behaves in direct response to major infl ow rates and loads. 20

WATER September, 1983

Iron

Org x 10' per day

mg/ L Campaspe Ri ve r at Redesdale-Site 24 Low Flow 26 ML/d Medium Flow - 358 ML/d High Flow - 680 ML/d

Salt

An examination of rainfall and stream flow data over an 88 year period showed that inflows in excess of twice the average occurred on ten occasions which indicates that as a long term average, turbidity levels of 15-20 NTU can be expected in the lake at an annual frequency rate of one in nine. However , urban demand would lik ely be supplied by the Coliban storages at these times. Using a mathematical model it was possible to predict that even with inflows four times the average over three months, followed by average inflows, the turbidity level would peak at 24 NTU and would then fa ll rapidly as settlement occurred. Catchment features noted as affecting solid s and turbidity levels are land di sturbance due to housing, on farm development, roading, gully side erosion and natural geological characteristics . Runoff water collected from the residual club sites and caravan parks around the lake, and from the watercourse through Redesdale did show generally high levels of suspended material.

Bacteriological factors

It was found that £. coli counts var ied directly with flow, e.g. for the Campaspe River at Redesdale the figures obtained were: • low flow 22/ 100 mL • medium flow 880/ I 00 mL • high flow 2300/ 100 mL Similar results were obtained for the Coliban River, Wild Duck Creek and Mt. Ida Creek. The major inputs into the lake were therefore via the major inflowing streams . However , notwit hstand ing the effect of these streams upon faecal bacteria inputs, it was shown that lak eside activity and recreation gave positive counts as high as 34/ I 00 mL on one occasion with up to 5/ 100 mL measured at the outlet tower. The fact that these results were obtained is probably due to the high ambient temperatures recorded at the time and short-circuiting of flow s within the reservoir.

• Field es1imate of fl ow.

As a general comment, it can be said that under 'normal' conditions, the lake can assimilate a lar ge bacteriological load , however, at specific times bacteria can survive up to the outlet tower. Care should therefore be taken in the use of the lake and regard be given to the fact that it is used after ch lorination for domestic supply puposes. Iron and Manganese (and other metals)

The leve l of soluble iron concentration in the lake water due to anoxic condit ions in the hypolimnion when the lake is stratified is important, since together with manganese, it is respons ible for the prol iferation of bacterial film in the Eppalock pipeline. It can also cause disag reeable taste, discolouration of washing and can affect the taste of beverages such as tea . The gr~wths also increase the pipeline friction head , thus reducing the rate of delivery of water. Sources of iron (and manganese) were establis hed to be the Campaspe and Co lib an Rivers in 1978/79. However, in I 979/ 80 Wild Duck Creek contributed 20.3 per cent of the total load, indicating that despite its sma ll flow, it is a significant source of iron. It was also established that iron is largely associated with suspended solids, a factor which infers the need to control carefu ll y soil disturbance in the Wild Duck Creek catchment. Recent trials have confirmed that so luble iron levels in the lake water can be controlled by the use of hypolimnion aeration, and this procedure is being examined as a complement to swabb ing of the Eppa lock-Bendigo pipeline. It is also an option for contro lling peak concentration levels whi ch are experienced from time to time. O.ther heavy metals measured were zinc, copper, lead and cadmium, however, they were barel y detectable and hence of no concern. Total Dissolved Salts (TDS)

Historical data for the Campaspe River , taken together with data coll ected on the lake

since filling, shows the river TDS valu es have fluctuated widely from 132 mg/ L to over 900 mg/ L, whilst the lak e has smoothed out this variation (169 mg/ L to 450 mg/ L). · The available evidence shows there is no upward trend in lake TDS and provided dry land saltin g can be conta in ed or decreased, salt levels in the lake can be maintained at current values, if not improved. REGRESSION ANALYSES

Attempts are being made to establish whether there are any strong correlations between catchment factors and specific quality characteristics. The multiple regression analysis approach is proving quite usefu l, although the statistical interpretations are very difficult. Table 3 gives a summary of current correlations in broad terms. SUMMARY OF LAKE EPPALOCK WATER QUALITY

As a general assessment it can be said that the monitoring programmes have established the following factors regarding the lake and its catchment: • Suspended so lids (and turbidity) at levels higher than those currently experienced cou ld cause problems with disinfection of water drawn-off for supply to Bendigo. • During the right conditions, faeca l bacteria contamination in the lake water, can reach the outlet tower.

TABLE 3: PRINCIPAL FACTORS AFFECTING WATER QUALITY AS DERIVED FROM MULTIPLE REGRESSION ANALYSIS Characteristic

Salt E.coli Turbidity Suspended Solid s Colour Total Phosphorus Nitrate + Nitrite Iron Manganese ND

Factors affecting characteristic Concentration

Load

- NS/ - Erosion/ - Flow + Rain / + Graded roads + Flow/ + Sealed roads/ + Rain + Flow/ + Sealed roads/ + Rain + Rain / + Graded roads/ + Flow + Flow/ + Sewered houses/ + Flow + Non-P fertil izer/ + Unsealed roads/ + Sealed and kerbed roads + Flow I + Sealed roads

+ Crops/ + Hou ses/ - Non-P fertil izer ND - Septic systems / - Sheep + Septic systems/ + Sheep ND - Plutonic/ + Volcanic/ + Sedimentary + NS/ - Rain / - Sealed and kerbed roads + Septic systems/ + Crops/ - AW septics + Catt le/ - Septic systems

- Rain / + Relief/ - Erosion

= not done (difficult y of fittin g ver y large numbers into computer working area) .

• Examination of historical river TDS information, together with lake data indicate that the TDS in the lake is not increasing and could in fact, reveal a downward trend in future years. • Iron and manganese is associated with suspended solids in the input streams. Soluble iron levels can be contro lled by artificial aerat ion techniques, thus co ntrolling the proliferation of iron and manganese bacteria in the Eppalock pipeline. • Monitoring of perimeter lessee premises revealed positive co unts for £ . coli, supporting the need to disinfect water pumped from the lake prior to use .

= disianc

outh of the dam wall .

Catchment and major stream characteristics are such as to suggest that controlled development must be practised to preserve the lake in its current situation.

REFERENCES Commonwealth Department of Health, National Health and Medical Research Council, Australian Water Resources Council (1980), 'Desirable Quality for Drinking Water in Aust ralia' , 1980. Inter-departmental Committee on Lake Eppalock (Gillard) (1981), Lake Eppalock and its Catchment, Water Quality Requirements a nd De sirable · Development Levels, I98 l.

ERRATA

D. BARNES Con tinued from page 16

Koe and Brady -

REFERENCES 12. G. M. Fair, J . C. Geyer and D. A. OKun. 'Water and Wastewater Engineering , Vol. 2, Water Purification and Wastewater Treatment' John Wiley & Sons , N.Y. 1968. 13 . r:i. Roy, P. K. Y. Wong, R. S. Englebrecht and E. S. K. Chian. Mechanism for enteroviral inactivation by ozone. Applied Envir. Microbia l., 43, 7 18-728, 1981. 14. J . C. Hoff. The relationship of turbidity to disinfection of potable water, in Evaluation of the microbiology standards for drinking water C. W. Hendricks Ed., E .P.A. 570/ 9-78-006, U.S.E.P .A. Washington, 1978 . 15 . W. Kuhn and H. Sontheimer. Treatment; improvement or deterioration of water quality, Sci. Total Envir. 18, 219-233 , 198!. 16. C. Nebel, R. D. Goltschling, J. L. Holmes and P. C . Unangst. Ozone oxidation of phenolic effluent. Purdue Ind. Waste Conj., 31, 940-952, 1976. 17. M. Dore , B. Langlais and B. Legube . Ozonation of phenol and phenoxyacetic acids. Water Research, 12, 413-425, 1978. 18. P. V. Roberts. Chlorine dioxide: state-of-t heart, in Proc. Wastewater Disinfection Alternatives State-of-t h e-Art Workshop, W.P.C.F . Conf. Houston, 138- 167, 1979. 19. G . Gordon, R. G. Kieffer and D. H. Rosenblatt. The chemistry of chlorine dioxide, in Progress in Inorganic Chemistry, S. J . Lippard, Ed., Vol. 15, Wiley-Interscience, N.Y., 1972.

•

20 . M.A. Benarde, B. M . Israel, V. P. Olivieri and M. L. Granstrom. Efficiency of chlorine dioxide as a bactericide Appl. Microbial., 13 776-7, 82, 1965. 21 M.A. Benarde , W. B. Snow , V. P . O livieri and B. Davidson. Kinetics and mechanism of bacterial disinfection by chlorine dioxide Appl. M icrobial., 15, 257-265, 1969. 22. R. E . Selleck, B. M. Saun ier and H. F. Collins. Kinetics of bacterial deactivation with chlorine Proc. Am. Soc. Civ. Eng., J. Envir., Eng. Div. , 104, I [97- 1210, 1978. 23. E. M. Witkin. Ultraviolet mutagnesis and inducible D.N.A. repairs in Escherichia Coli. Bacteriological Reviews 40, 869, 1976. 24. 0 . K. Scheible and C. D. Bassell. Ultraviolet disinfection of a secondary wastewater treatment plant effluent in Proc. Wastewater Disinfection Alternatives - State-of-the-Art Workshop, W.P.C.F. Conf. Houston, 168-212, 1979 . 25. J . E. Cruver. Ultraviolet disinfection of wastewater , presented at 25th Great Plains Wastewater Design Conf., Omaha, 1981. 26. J. K. Carswell. et al. Ozone, chlorine dioxide and chloramines as alternatives to chlorine for disinfection of drinking water, in Water Ch lorin ation: Env ironmental Impact and Health Effects, R. L. Jolly, H. Gorchev and D. H . Hamilton, Ann Arbor Sci., N.Y., Vol. 2, 550-560, 1978.

June Issue

The captions to Figures 3 and 4 should be corrected as follow s: Figure 3 to read - Figure 4. Contours of sewage odour conqmtration Cn (sou/ m') at Tivoli WWTP, 15 / 11/79, 6 p.m. to 9 p.m. session . Figure 4 to read - Figure 3. Contours of sewage odour concentrations Cn (sou / m') at Tivoli WWTP, 6/ 9/79, 6 p.m. to 9 p.m. session.

INTERNATIONAL SPECIALIST CONFERENCE Darwin, 4-9 Sept., 1983 The Water Regime in Relation to Mining, Milling, Waste Treatment and Rehabilitation with Emphasis on Uranium Mining Complete volume of the 32 papers presented is now available App ly: Conference Secretariat , PO Box 37283, Winnel lie, N.T. 5789, Aust.

Price: $60 internal , $70 overseas WATE R September, 1983

PLANT AND EQUIPMENT KENT

ACROMET

SALES/SERVICE CENTRE DARWIN

PUMP LITERATURE

Kent Instruments (Australia) now serve the needs of users of industrial instrumentation and process control equipment in northern Australia through a new regional sales /service centre in Darwin. The resident sales/service engineer is Mr Elvio Ladora who has been with the company over 11 years and has a wide range of experience of industrial instrumentation and of computer systems. Prior to Darwin he spent some five years in the W.A. Division of Kent. The new centre address is: Kent -Instruments (Australia) P/L, 1737 Albatross St., Winnellie, NT 5789. Phone (089) 84 4611.

•

• o·ELTA

FREE CHLORINE SENSOR The Delta Scientif ic Free Ch lorine Sensor employs a polygraphic mem brane sensor and has an operating range of 0.20 ppm with an accuracy of ± 3% of full scale . Its application is in water and wastewater treatment and industrial process in g. Available in models for submersib le or flow -through app li cations , advantages include quick installat ion , simple membrane replacement , elimination of reagents , automatic temperature and pressure compensation .

New l it erature is availabl e from Acromet covering many of the wide variety of pumps handled by the Com pany and including: Vanton Chem-Gard centrifugals Vanton Prime-Gard self-priming, plastic CCGH bearingless Bulletin TL-59 - on plastic pumps PVDF pumps with special leak-proof seal Details from : Acromet (Aust) Pty. Ltd ., 14 Winterton Rd. , Clayton , Vic. 3168.

TECHNICON FIL TERI NG SYSTEM The Technicon system consists of a disposable plastic tube with an inert fi lter in the base. When pressed slowly into a samp le, particulate matter is forced to the bottom of the container while clear filtrate passes through the filter in to the reservoir on the tube. The fi ltered sample is placed on the samp le tray for direct aspiration into the Auto Analyser system .

MONO PUMPS

THE ABS PIRANHA This low cost , submersib le sewage pump grinds so li ds sma ll enough to feed through a narrow and long discharge line . Maximum capacity of this new unit, the smallest in the range, is 5400 L/h making it suitable for sparsely populated suburban areas, restaurants, hotels, hospitals, abattoirs and such .

Saves time, laboratory space and glassware in particulate removal for analyses of environmental samples, groundwater and drainage, soils, tobacco, foods . Enquiries to Technicon Equ ipment P/L , Melbourne , Brisbane, Perth , Adelaide.

HACl-1 DR/3 SPECTROPHOTOMETER FOR ALL ANALYSIS The DR/3 incorporates innovations in circu itry and performance inc reas in g the versatility and performance of the proven DR/2 . With greater sensitivity without the need of expensive accessori es, the improved photodetector gives better coarse and fine span contro l with locking mode making standardisat ion eas ier. The portable model operates on batteries or mains supply and has optional built-in conductivity meter for specific conductance, TDS and temperature measurements.

Chlorine readings are displayed on 4 ½ inch analog meter, 4-20 ma de output signal is transmitted for recording or data logging. Details: John Morris Scientific Ply. Ltd., PO Box 80, Chatswood, NSW 2067 or state offices. 22

WATER September. 1983

The Piranha shreds all destructible matter and requires only a 25 mm discharge line . There are now four models available giving flows ranging to 19000 Uh and heads to 35 m. Enquiries to: Mr. K. Lapinskas , Product Manager, Sewage Pumps, Mono Pumps (Aust.) Ltd ., PO Bo x 123, Mordialloc , Vic. 3195.

The laboratory model includes a 0.1V recorder output permitting graphic display of results for repetitive samples and photometric titrations.

Hach provide a handbook describing 99 different water tests and offer reagents and apparatus for measurement of many water, wastewater and in dustrial parameters . Enquiries to Selby Sc ientific in all states.

Take the work out of culture media preparation

SARTORIUS NUTRIENT PADS AND DISPENSER • pads are impregnated w ith a nutrient medium, addition of sterile water produces a culture medium • sterile, packed in a practical dispenser • economical and time-saving • choice of 22 different pad types • long shelf life Typical water testing applications: E. coli and coliforms, Enterococci , Pseudomonas aeruginosa and colony counting . Available fro m

SELBY SCIENTIFIC QLD 37 1 1566

NSW 888 7155

TAS

28 4691

51 4651

ENVIROSHIELD

VIC

544 4844 WA 45 1 2577

Laboratory (Queensland) For Independent Analysis of Water and Wastewater

For further information: C.I.G. Enviroshield, 1688 Ipswich Road, Rocklea, Brisbane 4106 Phone: (07) 275 0196 Telex: CIGAS AA40498 WATER September, 1983

• For expertise in difficult applications

• compression plant• blowers •valves

Donkin provide conventionally lubricated reciprocating compressors, or oil free units suitable for applications where no trace of oil must mix with working gases. Single and multi-stage centrifugal units are also available. Working up to 48 MP a gauge , Donkin compressors can be particularly suitable for 'difficult' gases such as coal and natural gas , petroleum refinery process products, ammonia and carbon dioxide.

Donkin supply rotary blowers, boosters and exhausters - eith er centrifugal or the simple and robust Roots type. Major uses include smelter gas exhau sting , fuel gas boosting , sulphur dioxide handling in acid plants, materials handling and providing air for sewage treatment. These low-pressure machines are available for high volumes - up to 170,000 cubic metres per hour.

The Donkin valve range includes gate, butterfly and non-return valves for the control of fuel gas mains, air, coke oven hot gases , corrosive sulphurous gases, or process gases in industry. Units are available from 600 to 1200 mm , even to 1800 mm pipe bore size.

Donki n products, associated with the gas industry for 150 years, are utilised in gas co mpression and control for process engineering , indu stri al gas supply and pn eumatic co nveying in every part of th e world.

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Head office: 262-284 Heidelberg Road, Fairfield Vi c. 3078 . Tel: 489 25 11 Branches: Sydney, Brisbane, Perth . Hawker Siddeley Group supplies electrical and mechanical equ ipment with world-wide sales and service.

3397 HSE 10

WATER

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Centrifugally spun cem ent mortar lining f ora clean, hydraulically-srnooth, corrosion-free bore.

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