Water Journal September 1982 by australianwater

j 1ssN 0310-03 67

Official Joarnal of the

rA•~ii;t~MM:l!Mii=t;E~l•J Ml--ii=WMi3;'*i-i•XeJMit•1:1 0

Registered b

ustralia Po st -

publication no . VBP 1394

I "

Vol.

, No. 3, Sept. -4 982 •

$2.00

SEWAGE ODOR CONTROL wi th ACTIVAT ED CARBON SIMPLE

. .....

RELIABLE

. ECONOMICAL

The AQUA-WRIGHT SOC units are spec iall y designed for sewage odour contro l. Uti lis ing GRANULAR ACTIVATED -1 CARBON they have proven comp letely effective in elim inating citizen odour comp laints. Consultants and Authorities recognise AQUA-WRIGHT Sewage Odour Contro l Units as the most effective means to remove sewage odours. Already more than 30 of these units are in operation throughout Austra lia, giving simp le, reliable, economical service. Hydrogen Su lph ide and odo ur causing organ ics are removed by pass ing the odorous airstream through a bed of activated carbon. Purified air is vented to the atmosphere. AQUA-WRIGHT S.O.C. units are effective for high , low or vary ing concentrations of odorants , in large or small airf lows. Our systems are based on improved activated carbon technology to give you a more efficient and economic approach to sewage treatment plant odour control. Comp lete packaged adsorption un its are availab le in f lows from 25 to 3000 li tres /second. The units are bu ilt with corrosion resistant materials and are engineered so that noise and maintenance are minim ised. The only moving part is the blower/motor assemb ly. For SIMPLICITY, RELIABILITY & ECONOMY in sewage odour control, write or telephone us today.

AQUA-WRIGHT A division of Wright and Company Pty. Ltd . Head-office 32-40 Maddox St . , Alexandria, NSW 2015, Tel. 51-3371, Telex 24237 Branches in Brisbane, Melbourne, Adelaide, Perth

EDITORIAL Chairman, F. R. Bishop E. A. Swinton Mary Drikas Dr. Wayne Drew W. Rees J.H.Greer C.Tucak R. McGrath J.E. Dymke D. Hammerton R. Camm J.Paul A.Payne 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 062-89-1777 NEW SOUTH WALES W. H. Rees Inv. Eng., Advance Planning M.W.S.&D.Bd.

P.O. Box A53 Sydney South 4000 02-269-6595 VICTORIA E. A. (Bob) Swinton, C.S.I.R.O., P.0. Box 310, South Melbourne 3205. 03-699-6711 QUEENSLAND D. A. Simpson Munro, Johnson & Ass. PIL P.O. Box 57 Spring Hill 4000 07-221-6616 SOUTH AUSTRALIA B. P. Maguire Inv. & Policy Branch E. & W. S. Dept. Victoria Sq. Adelaide 5000. 08-227-3966 WESTERN AUSTRALIA C. M. Tucak, 18 Ventor Ave., W. Perth 6005 09-321-2421 TASMANIA G. Nolan, 20 Browne St., W. Hobart. 002-28-0234 NORTHERN TERRITORY J. Paul, Water Div. Dept. of Transport & Works, P.O. Box 2520, Darwin 5794. 089 89 6077 EDITORIAL & SUBSCRIPTION CORRESPONDENCE G. R. Goffin, Â· 7 Mossman Dr., Eaglemont 3084, 03-459-4346 ADVERTISING Miss Ann Sykes,, Appita, 191 Royal Pde., Parkville 3052. 03-347-2377

WATER

Official Journal of the AUSTRALIAN WATER AND WASTE WATER ASSOCIATION

Vol. 9, No. 3 September 1982

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

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

Chlorine Dose and Trihalomethane

Formation -N. H. Pilkington . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

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

Water-Pristine Pure? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

Intermediate Sedimentation with Two-stage Biological Filters -K. J. Hartley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Australian Society for Limnology -21st Conference-Griffith N.S. W.. . . . . . . . . . . . . . . . .

Book Reviews-Letters . . . . ..... . .. . .. . . .. .... ( . . . . . . .

COVER The Barossa Water Filtration Plant, 39 km north east of Adelaide, will supply filtered water to the northern plains of Metropolitan Adelaide. It will be the third of six plants proposed ultimately to filter all water supplied to the Metropolitan area. With a capacity of 160 ML/d. The plant has been designed and constructed by the Engineering and Water Supply Department and it will be commissioned in late 1982. The plant will draw water from the Barossa Reservoir, an off-stream storage which is supplied by the South Para Reservoir and the Warren Reservoirs. River Murray water from either the Swan Reach-Stockwell or Mannum-Adelaide pipelines can be used to supplement the system demand. The Barossa dam (background), a thin wall concrete arch completed in 1902, has been named the ' Whispering Wall' because of the unique acoustic phenomenon of transmission sound and voices around the 144 m curve of the dam . The statements made or opinions expressed in ' Water ' do not necessarily reflect the views of the Australian Water and Wastewater Association, its Council or committees .

SEPTEMBER 1982

To offer little or nothing takes a lot ... It takes Kent Veriflux - quite simply the most advanced and reliable Electromagnetic Flowmeters in the World . Kent Veriflux gives you the choice of bi-polar d.c. pulse or a.c. flux sensing systems, a wide range of detector heads from 3mm up to 1600mm size plus guaranteed accuracy of ± 0.5% offlowrate. Of course, Veriflux flowmeters are made in Australia by Kent and are calibrated in the NATA registered flowmeter calibration laboratory at the Kent Caringbah, N.S.W., factory.

Little • Low power consumption - only 12 to 27 watts with d.c. systems. • Less circuitry and less complexity • Reduced weight • Lower installation and service costs

Nothing • No zero drift • No submersion problems • No bore obstruction - no pressure loss • No electrical interference problems With Veriflux Kent offers you little or nothing but gives you a lot.

BBC

Kent Instruments (Australia) Pty Ltd

PJ 4197

Sydney (02) 525 2811 Melbou rne (03) 874 1233 Brisbane (07) 369 131 1 Perth (09) 277 5377 Adelaide (08) 352 1455 Townsville(077) 71 2555 Canberra (062) 51 5659 Launceston (003) 81 1222

BROWN BOVERI

Lime... the pollution fighter. Lime is one of the most efficient pollution fighters known to man . Thanks to the versatility of Lime, it's possible for us to breathe cleaner air, drink purer water and eat better food . Lime purifies , clarifies and neutralizes, removing undesirable elements from water , sewage , smoke stack gases, industrial wastes and mining discharges .

WATER

\Ulii\

r For further information , send this coupon to:

II Dovid Mitchell Estate Limited,

David Mitchell Estate Limited TAS: P.O. Box 68, MOLE CREEK , 7304. Phone: (003) 631187

range of benefits .

Lime .... the versatile chemical

You should be looking to Lime's exceptional efficiency and low cost.

VIC: P.O. Box 486 , LILYDALE, 3140 . Phone: (03) 7350644

Lime can also: • Absorb • Alkalize • Beneficate • Causticize • Clarify • Coagulate • Dehydrate • Disinfect • Flux • Neutralize • Plasticize • Purify • Precipitate • Refine • Stabilize Learn more about Lime 's remarkable

P."O. Box 486, Lilydale, Vic., 3140.

I NAME

I ADDRESS ............................................ .

OLD: Calcium Products Pty. Ltd. , PO Box 224, AYR, 4807. Phone (077) 788743

I I I . ············ 1

· I

·······

I I .I I I I COMPANY NAME ....................................... ...................... . L - -- - - - - - - - - - - - - - - - - - - j

SEPTEMBER 1982

For Resource Recovery and Pollution Control there's just one name to remember...

EIMCO Thickeners - Centre Drive/Column Type

EJMCO Belt Filter

There are a lot of important riames in the fields of resource recovery and pollution control - names like EIMCO, WEMCO, Shriver, Goslin, Carrousel<!> and ASH. But one name - Envirotech - covers them all. Together with broad engineering design and manufacturing skills, Envirotech offers the continually up-dated technology of acknowledged world leaders. When you need equipment for ... • Flotation • Heavy Media Separation • Thickening & Clarification • Vacuum, Gravity & Pressure Filtration • Water & Wastewater ' ·Treatment ... there's only one name to , remember.

WEMCO H.M. Separation Drum

Envirotech Australia Pty. Ltd. A Company in the Engineering Division of Mitchell Cotts Carrousel®Sewage Treatment Plant

SEPTEMBER 1982

Sydney

Perth

1021 449 4222 Telex: AA21775

109) 321 4541

WATER

AUSTRALIAN WATER ANDI WASTE WATER ASSOCIATION I

VIEWPOINT

FEDERAL PRESIDENT D. J. Lane, State Water Laboratories , E. & W.S. Department , Private Mail Bag , Salisbury, 5108

FEDERAL SECRETARY F. J. Carter, Box A232 P.O. Sydney South , 2001.

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

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

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

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

Queensland K. Strickland, C.I .G. Ltd ., P.O . Box 40, Rock lea 4106.( 07 275 0111)

South Australia A. Glatz, State Water Laboratories, E. & W.S. Private Mail Bag , Salisbury , 5108. (258-1066)

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

Tasmania P. E. Spratt , Ci- Fowler, England & Newton , 132 Davey St., Hobart , 7000. (23 -7591)

Northern Territory J. Kenworthy , G.H. & D. P.O. Box 351 , Darwin 5794 . (089-81-5922)

WATER

OUR AFFILIATIONS One of the objectives of the Australian Water and Wastewater Association is to ' liaise and establish affiliation with related organisations at home and abroad'. Within Australia this policy is being actively pursued and liaison has been effected, both at State and Federal level, with the Institution of Engineers. We have been represented at meetings of the College of Civil Engineers of the Institution and their representatives have attended our Federal Council meetings. This interchange will be further developed to the mutual benefit of both organisations . Affiliation with overseas organisations is more complex, and in some cases involves considerable expenditure by the Association. The main international bodies of concern to our Association are the International Association for Water Pollution Research and Control (IA WPRC-formerly IA WPR), the U.S . Water Pollution Control Federation (WPCF), the American Water Works Association and the International Water Supply Association. The IA WPRC in Australia is controlled by the Australian National Committee. Prior to 1976, IA WPR acted independently of the Australian Water and Wastewater Association. However following the successful joint Conference in Sydney in I 976 , a close working relationship has been maintained between the two bodies. This affiliation does not involve any expenditure by A WW A. A WW A is a member of the Water Pollution Control Federation and a representative of A WW A is required to attend every second annual meeting of the Federation. The cost of travel for this purpose is borne by A WWA . The WPCF provides a valuable point of access to information and publications on water pollution control and this affiliation is strongly supported. The Federal Secretary of A WWA is sponsored by the Association as a member of the American Water Works Association. This contact complements that provided for wastewater throu gh the WPCF. The A WWA is a Corporate Member of the International Water Supply Association and the A WW A Executive is the Australian National <;ommittee of that Association. As IWSA is centred mainly about Europe, with headquarters in London , attendance at meetings is time consuming and expensive, with little apparent benefit to A WW A . Advantages of affiliation with IWSA are not clear. Financial support for international re lationships is provided by the major water authorities in New South Wales, Victoria and South Australia. These funds are used to cover the cost of attendance at IA WPRC a nd IWSA meetings. The cost of Corporate Membership of IW SA is high and the minimum attendance at meetings in Europe- once every two years-is expensive and there are doubts as to the technological benefits. The funds involved might be better employed in bringing overseas specialists to Australia . With the rapid rate of technological change, it is unquestioned that A WWA should foster all fruitful international affiliations and this should include closer ties with Japan and other Asian countries because of our shared technical, geographical and trade interests. If IWSA can offer a channel of communication in this area, maintenance of association could have merit. The President of IWSA will be with us for the 10th Federal Convention in April, his visit will provide an opportunity for discussion of these matters and the question of continuance of A WW A affiliation with IWSA . DOUG LANE Federal President

SEPTEMBER 1982

ASSOC/A TION NEWS VIEWS AND COMMENTS PRESIDENT'S MESSAGE NATIONAL WATER RESOURCES PERSP ECTIVES

In May 1982 thi s Association was invited to prepare a submission to the Steering Commit tee on National Water Resources Perspectives to the year 2000. Thanks to the persistence of Vice President Frank Bishop and the support of Branches, a seven page statement was for warded within the prescribed time. The preparation of thi s submission is consistent with the policy of our Association for greater involvement in National water issues. 21st ANNUAL REPORT

A final draft of this publication will be avai lable to the November meeting of Federal Council, immediately prior to printing. RULES

The final draft of the Rules was approved by the Executive Committee on 20th August, I 982. Action regarding the Plebiscite was initiated at that time . As I will be retiring as President at the completion of my two year term in November of this year, this is the last time I will use this column . I would like to record my sincere appreciation for the support provided by Federal Executive, Council and Branch Committees. DOUG LANE Federal President

* * * *

VICTORIA BRANCH ACTIVITIES

The June meeting was a very practical description of the pipeline being installed to take away about 35 ML/d of highly saline waste from the ash sluicing systems of the Loy Yang Power Station. Fifty-six kilometres long, the line will discharge into the Bass Strait. The pipe is 610 mm O.D . in width and 6 mm thick mild steel, protected by 0.4 mm of high-build epoxy resin on the inside . The outside, when buried, will be covered by 2.5 mm of polyethylene, or, if above ground , by zinc-rich epoxy primer with MIO epoxy topcoat. The joints are rubber sealed. Laurie Reilly and Malcolm Hannan of the S.R.W.S.C. described the testing system designed to ensure that the landscape is not sprayed with the wastewater . A mobile "holiday'' detector scanned the surface of the 12 m lengths, and any flaws were rectified immediately. On July 27th Roger Vass of the M.M. B.W ., fresh from an overseas study tour, talked about the concept of 'multiple lines of defence' required to protect against contamination between the catchment and the consumer. This concept assumes that no 6

single treatment process can be relied upon to provide l 00 per cent protection against transmission of disease, an d has been proposed in various health and water control publication in the U.K. since 1939. T ypical 'lines of defence' would be contro l of catchment pollution, long storage, fi ltration, and finally chlorination, with the latter being most suscept ible to operational failure . Roger demon strated how a computer model might be built up to evaluate the risk of failure in any one parameter, and its effect on water quality . The paper was an interim report, and no easy solution to the application of the model to multiple catchments has yet been developed. Wayne Drew and Gordon Hirth, both of S. R.W .S.C ., described in August the experiments now bein g run under the auspices of the Ministry for Water Resources on the re-application of slow sand filtration. This process has been known for 150 years, and is used quite widely in Europe a nd for most of London's supplies . Why investigate it in Australia in 1982? This is because despite its engineering simplicity, the purification process relies on the biological activity of the "schmutzdecke" which is complicated by a numberr of parameters including solar input. The project should assess the process merits in competition with the conventional alum floc culation and rapid sa nd filtration. Interim result s indicate the possibility of 'horses for courses', but the final report may define the choice more accurately. September 15th sees the Annua l General Meeting complete with smorgasbord promising a variety of delicacies (at the S.W .R.C ., 6.30 p.m.) and the retiring President talking on 'Waler and Wastewater Treatment in Victoria-Warts and all' . October brings us to the Spring Breakout, Bendigo, 9th- 11th.

For sewerage , a major system is nearing completion in the northern sector at Corio. These works will reli eve loading on the present system and provide an important link for conveyance of wastewater from Lara . At Black Rock outfall, the performance of a "Screezer" is being evaluated as a possible replacement for the existing (and ageing) comminuters. In conjuction with the Water Commission and Department of Minerals and Energy, possible utilisation of the ground and surface water resources of the Gellibrand River Catchment is under investigation. A further project with other Authorities is a two year programme to collect data on water quality and quantity throughout the Barwon and Moorabool Catchments and Rivers.

•••• M.M.B. W. CHAIRMAN RETIRES Alan Croxford retired at the end of July after 16 years as Chairman of the Melbourne and Metropolitan Board of Works, Me lb ourne's water supply, sewerage, drainage and town planning authority. During his term, he presided over the most dynamic construction period in the Board's history in wh ich three major water storages were constructed ; nearly 30 ki lometres of tunnel were excavated to divert water from the Thomson River for use in the metropolitan sy~em and a start was made on the giant Thomson Dam with a capacity of more than I. I million megalitres of water.

•••• STATE NEWS-GEELONG ACTIVITIES

Geelong Trust's extensive capital works programme ($30 million over the past three years) includes the Wurdee Boluc-Pettavel Pipeline, 19 km of 1,675 mm I.D. steel pipe which is due for completion at the end of this year. Built at an estimated cost of $15 million and with a gravity capacity of 300 ML/d, the line will approximately double the capacity of the present open channel system-a marked improvement to the system. Work is also progressing on a $5 million groundwater scheme near Barwon Downs which when completed in late winter 1983 will increase the safe annual yield of the Trust's Barwon Water Supply system by some 8000 ML. Other water supply works in the Geelong urban area include a number of large transfer and feeder mains and will involve more than 30 km of steel pipeline from 600 to 1450 mm diameter. SEPTEMBER 1982

In the same period, the Board constructed the South-Eastern Sewerage System, lightening the burden on the Werribee Treatment Farm and enabling the provision of sewerage facilities to many areas wh ich could not previously be served. Alan took marked interest in A WW A activ ities and was the source of considerable and much appreciated assistance to the Association. We wish him well in hi s retirement. He is succeeded by Mr. Ray Marginson as part-time chairman. A full time General Manager is yet to be announced. WATER

....

ASSOC/A TION A.C.T. BRANCH ACTIVITIES

Branch activities have resumed and it is a pleasure to report progress over the last few months. On June 10th, T. Daniell and K. Paine, both of the Department of Transport and Construction, A.C.T. presented a talk to the Branch on the 'Simulation and Operation of Multi-source Urban Water Supply Systems'. July saw a joint meeting of the Branch with the Canberra l3ranch of the Hydrological Society, held on the 13th. The speaker, Dr. J. Burgess spoke on 'The Bacteriological Content of Village and Tuggeranong Creeks'. The Annual General Meeting was held on August 19th, the guest speaker being Dr. A. Jarmin of' the Australian Centre for Local Government Studies, Canberra - his subject, 'The Interrelation of the Professional and th~ • Executive in Public Authority Organisations' .. The report of this meeting and of CRiri!llittee appointments is not to hand as-we· go to press and will follow in the next isstfe. ~

..:'QUEENSLAND BRANGH 'ACTIVITIES

Committee.and Office Bearers for 1982/ 83 are: President, :John Ryan; Vice-President, Keith Strickland; Im. Past President, Brian Riggen; ·Secretary, Ian Bell; Treasurer, Norm Whyte; Membership Secretary, and Asst. Treasurer, Michael Bowe; Asst. Secretary, David .Pettigrew; Correspondent, David Simpson ; Programme Officer, Rod Lehmann; Federal Councillors, John Ryan and Brian Rigden; Committee Jack O'Connor, Robin Black, Don Mackay, Humphrey Desmond, Alan Pettigrew, Bill Solly, Col Richardson. At the meetjng on 30th June, Rod Lehmann of Sinclair Knight and Partners spoke on 'Inflow-Infiltration Studies of Sewerage Reticulation Systems'. At the meeting on 14th July, Brian Ridgen and Eleanor Thomas of the Queensland Institute of Technology and Ross Sadler and Phil Carson of the. Department of Local Government combined to present 'Biodisc Treatment of Sugar Mill Waste'. Both evenings were interesting and produced some lively discussion. Operators' certificates were presented on both occasions. Fred Greenhalgh who retired as Engineer for Design , Water Supply and Sewerage with Brisbane City Council in March 1981 and is currently a Specialist consultant to Munro, Johnson and Associates presented 'Sewering of Brisbane-Some Reminiscences' at the Annual General Meeting on 18th August. Among other aspects he explained how revision of design requirements i"n the mid '50s contained costs and permitted a boom sewerage progr~me for two decades from the early '60s. • On August 21th a seminar - 'Water QualiWATER

•

NEWS

•

VIEWS

ty Aspects of Residential Waterway Development' attracted an audience of 70 plus to hear papers presented by seven speakers drawn from the fields of biology, entomology, water sciences generally, consulting and municipal engineering. The papers created great interest and made clear that the development so far seen in south-east Queensland is only the forerunner of very extensive projects in the future. The programme for the remainder of I 982 includes: 28th October - 'Experiences in Papua New Guinea in Organising Water and Wastewater Treatment' by Vince Schmidt; 17th November 'Water Resources of Australia-Usage and Ways of Conserving Supplies' by Leon Henry. Keith Duncan retired from James Hardie at the end of July 1982. Murray Allen has retired from the Committee and also from his position as Federal Councillor. Thanks to both for your services to the Branch. Our thanks also to Leo Roessler, Clive Norton and Julie Ivison for services to the Committee. If you haven't already heard the news, the Town Water Supply and Sewerage Branch has left the Queensland Water Resources Commission and returned to its former home of the Department of Local Government as of 1st July 1982.

TASMANIA BRANCH ACTIVITIES

After a period of relative inactivity the Branch Committee decided upon the follow ing programme for the financial year. • July 6th: 'Solid and Liquid Trade Waste Studies in Malaysia' - Steve Hollis of Scott and Furphy. • August: Annual General Meeting. • November: Topic and date to be announced. • May 1983: Weekend seminar, 'Historical Aspects of Water Supply and Sewerage in Tasmania'. The location will be Swansea and members with information relating to the subject and \he area are asked to contact the Secretary . The subject of the July talk has already been covered in 'Water ' in the March issue but personal presentation by Steve Hollis from Scott and Furphy's Canberra Office was very much appreciated by over 20 members and guests. STATE NEWS

A number of projects in our field of interest are in hand or pending and in time, details will be provided. One major project under way is augmentation of the Derwent Water Supply to Metropolitan Hobart which will increase the system capacity by 150 ML per day. The programme calls for 27 km of 1371.6 mm O.D . mild steel cement lined underground pipeline to carry water from the Water Treatment Plant at Bryn Estyn. SEPTEMBER 1982

•

COMMENT

Pipe manufacture commenced at the Hobart Factory of Steel Mains P / L late last year and installation started in February last. Stage I augmentation of the treatment plant, pumping stations and of the pipeline is scheduled for September I984 .

WESTERN AUSTRALIA BRANCH ACTIVITIES

On June 22nd some 50 members attended the final general meeting for the I 981-82 session, when the award of onorary Life Membership to Don Montgomery was announced as reported in June 'Water'. The Certificate of Membership was presented to Don for hanging in his favourite room . Then followed a very successful mini seminar on the Peel Inlet with its problem of Phosphorus entry and deposition and algal growths presented by: • Dr. E. P. Hodgkin who gave a summary of the problem and cures less likely to succeed and why. • Mr. P. B. Birch who spoke on ways of reducing the phosphorus at its source. • Mr. J. 0. Gabrielson who spoke on chemical precipitation of phosphorus and the estuarine sediment store . • Dr. W. Andrews who summarised the potential for Engineering Solutions. Interim conclusions suggested improved farm management in the catchment areas of the rivers feeding into the inlet with possible large savings in cost of fertilizer to the farll) ing community or expenditure of the order of tens of millions of dollars , to effect an engineering solution to gain either improved flushing of the estuary or by-pass of the flow from the rivers. On August I 3th the Branch held its I Ith Annual General Meetfng. Although the date was inauspicious and the temperature in the low tens some 60 members and partners attended at 7 .30 to hear the outgoing President C. Tucak and Treasurer, P. Verschuer present their reports. Membership during the year increased dramatically by 32 per cent for individual memberships and 38 per cent for sustaining members. The growth appears to be continuing and on current predictions we should exceed a total of 200 members by the next Annual General Meeting . The growth after a very successful Federal Conference in I 98 I has resulted in a bonus of Funds to Federal Council, the Conference alone yielding a nett profit of some $9,500. The President commended the Branch Secretary, Rein Loo for his untiring efforts in administration of the Branch, arranging a record number of meetings and for having survived his editorial lapses and provocative reports while producing the Branch Newsletter 'Waisted Warters'. The Committee for the 1982-83 season is: President, Noel Platte!; Vice President, Bob Fimmel; Secretary, Rein Loo; Treasurer, Peter Verschuer; Committee-Peter Dundon; Ron Edwards, John Holbrook, Brian 7

ASSOC/A TION Kavanagh, Don Montgomery, Bruce Nelson, Barry Robbins , Barry Sanders, Charles Tucak and Max Wishaw. The President also commended the efforts of retiring Committeeman Jack Katnic who did r:iot seek re-election. The new President, Noel Platte! has been a Committeeman since the Branch was first formed. Noel is a W.A . Graduate in Chemistry and he is head of the Water Division of the Government Chemical Laboratories. His field includes treatment, management and problem solving in water supply and wastewater. Following a showing of the film 'Manganninie' the meeting adjourned to the supper room where struggling tables coped with a heavy -loading of chicken, champagne and other tasty items. A fitting (and late hour) · finale to our I 0th year as a Branch.

•

NEWS

•

VIEWS

SOUTH AUSTRALIA BRANCH ACTIVITIES

The Seminar 'Disinfection of Water Supplies' (July 23rd) mustered a pleasing attendance of 130 including a number from interstate. The Hon. Jennifer Adamson, Minister of Health opened the session by emphasising the importance of disinfection, particularly in South Australia.

•

COMMJ!NT

the Department described increased corrosion problems with chlorinated waters, particularly in the Morgan Whyalla pipeline dezincification of all pipes and fittings is one method of control in the home . The production of trihalomethanes was discussed by Mr. Bursill of the Laboratories, the significance, tastes , odours and finally approaches to control. The day's activities were rounded off by

STATE NEWS 'A Water Board by any other name . . .'

In 1980 the Metropolitan Water Supply Sewerage and Drainage Board of Perth streamlined the mouthful to Metropolitan Water Board. This resulted in some confusion between the Board of Control and the servicing body and led to the servicing Board being renamed the Metropolitan Water Authority in July 1982. With the change in name the Board membership was altered to seven with several new appointees. Board of control now consists of the Chairman, Mr. D. W. Zink and Messrs. H . J. Glover, K. J. Kelsall, F. Pinczuk, J. W. Dallimore, A. B. Wood. Both Mr. Kelsall and Mr. Wood are members of the W.A. Branch of A.W.W.A. Another change is the adoption of triennial revaluation of rateable properties with increases phased in over the three year period . With the valuation adjustments, annual rate increases will be limited to 40 per cent increments and optional methods of payments will be introduced yielding savings to the rate payer at very much the same cost to the Authority . A short testing period has produced no significant public comment which seemingly indicates the change to be successful. The move appears to be more sound than the change some years ago from full rating on property valuation to 'pay as you use' which coincided with bad drought, water restric'tions, corresponding reduced revenue to the Board and rate increases, restricted by the State Government. In its recent annual report the Authority estimated a five year expenditure of some $50 million each on sewage treatment plants, a new ocean outfall and sewers into built up areas with approximately $40 million on trunk sewers and pumping stations . On water supply an approximate expenditure of $30 million for trunk mains and service reservoirs and approximately $_50 million on service mains to consumers. 8

At the seminar (left to right): Ray Williams, Bob Clisby, Dr. John Rolls, Hon. Jennifer Adamson, Harry Hodgson, Jack Davis.

Dr. Mulcahy of the S.A. Institute of Technology introduced the first session 'Current Practice' with a thorough outline of the chemical aspects of chlorination, treatment chlorination, reaction rates and reactive species. Mr. Jantevics of !CI followed with an account of the history of the chlorine production process, present methods and control procedures . Also from J.C .!., Dr. Yates spoke of new means of production including the membrane cell which provides higher purity sodium hydroxide (as a byproduct) and longer membrane life . In the session "Technology and Effectiveness' Mr. Damien of the E.&W.S. described chlorinator types, dosages and locations and commented upon reliability. Mr. Walters of the Departments State Water Laboratories followed with a description of virus types and bacteria and the factors affecting control and target organism numbers. He then elaborated on methods of measurement of effectiveness of chlorination and interpretation and reliability of results . Mr. Robinson, also of the State Laboratories took up the story in discussing different types of amoeba particularly Naeglaria fowler, the cause of amoebic meningitis, in its various forms including the cyst stage which is most chlorine resistant. Other amoeba species are more resistant but note as deadly to humans. With a break for a most enjoyable dinner, Session 3 on 'Side Effects and Alternatives' was opened by Mr. Ridley of the E.&W.S. Department on the advantages of chlorination in maintaining the hydr.aulic performance of pipelines. Mr. Beckworth , also of SEPTEMBER 1982

Dr. Barnes of the University of New South Wales with discussion of alternatives available including ozonation, chlorine dioxide, chloramines and ultraviolet radiation. He spoke of production measures , effectiveness and by-products . Altogether a very successful exercise. Next meeting of the Branch will be the A.G.M. on September 24th when Mr. B. C. Stone of Brian Stone and Associates Perth will talk on 'Water Filtration Plant Operation Performance Compared with Design' .

NEW SOUTH WALES BRANCH ACTIVITIES

In early July an audience of some 80 enjoyed Prof. Wes Eckenfelder's technical magic when he spo le on 'The Treatment of lnustrial Wastewater' at the Water Board Theatrette on 8th July . He gave particular attention to the biological treatment of wastewaters containing high concentrations of soluble B.O.D . and slowly degradable and inhibitory toxic materials . After hectic sessions with N.S.W. Government agencies following his presentations at the Gold Coast Seminar, his time with the Branch was indeed appreciated. Disappointment turned to joy, as they say, when, following a viral illness of our speaker the Hon. E. Pickering, for the 21st July meeting, Geoff Kidd of Sedgman and Associates was able to stand in and address the Branch on 'Aspects of Water Use in the Coal Preparation Industry'.

The address which was very well received by an audience of some 45, covered the multiWATER

ASSOC/A TION treatment streams of a typical coal preparation plant and touched on two particular problems facing the industry, namely: • Are there alternatives to filter presses and the like for treatment/ disposal of waste tailing slimes? • Do mines have to have 'closed water' systems and why can't surplus saline water be disposed of by bleeding to natural drainage systems when flows are adequate? In an era when the Australian coal industry can compete internationally on productivity, but is burdened with Federal and State levies and transportation imposts , these are important issues for export livelihood. At the A.G.M. on August 12th , Office Bearers and Committee for the year were announced: President, Lance Bowen ; VicePresident, Tim Smyth; Secretary, D. Russell; Treasurer, J. Olliff; Committee M. Dureau, D. Stevens, T. Lawson, T. Tuyman, J . Eslake, G. Laughton, T. Judell, F. Randal, J . Brown, N. Brady, G. Douglas , H. Bandier and D. Garman. Dr. Garman and Mr. Randall were welcomed as new members to the Committee. Speaker for the night was Mr. R. Conoll y, C hairman of the Metropolitan Waste Disposa l Authority, who gave a most interesting talk on "Grappling with Sydney's Liquid and Solid Wastes Disposal Problem ". Mr . Conoll y made the members aware of the major planning and logistical problems in-

•

NEWS

•

VIEWS

volved in disposal of these wastes from a city the size of Sydney. The Newcastle Sub-Branch held a meeting on 12 July, where Mr. F. Kalk spoke on the 'Effects of Mining on Groundwater Resources'. The Sub-Branch held its Family Day at Silver's property at Halton on 18th July. This annual event was again very successfu l and enjoyable. Coming Events

September 17. Annual Dinner Dance to be held at the Sebel Town Hou se, Sydney, where Mr. Robert Mackeller wi ll be presented with the Water Board Gold Medal by Mr . E. Worrell, Presid ent of Metropolitan Water Sewerage and Drainage Board. September 25. The Newcastle Sub-Branch will hold its Annual General Meeting at the Belmont 16 ft. Sailing Club , where Dr . J. Paterson, President of the Hunter District Water Board, wi ll be the Guest Speaker. October 26. A joint Technical Meeting is to be held with the Institution of Engineers, Australia at Eagle House, Milsons Point. This promises to be yet another very successful joint meet ing between these two bodies. November 26. The Branch proposes to hold its Chirstmas Party at the Mandarin Club in the city. All members are urged to attend this happy social function. April 11, 1983. The 10th Federal Conven-

•

COMMENT

tion of A.W.W.A. at the Wentworth Hotel, Sydney. In Apri l, Sydney will be magnificent! The Convention Committee have an excellent two-stream technical programme arranged for the convention. On the social side, the unique attractions of Sydney, the Harbour, the Opera House, the Blue Mountains, the Hunter Valley are all included in tours and social activities. This convention promises to uphold the very high standard set in Perth and the Committee aims to surpass the success of the last convention. Registration will issue late in 1982. Enquiries to the Secretary, 10th Federal Convention, P .O. Box A232, Sydney South, Australi a 2000.

r---~----------------, CHANGING YOUR ADDRESS? PLEASE LET US KNOW! NOTIFY ADDRESS CHANGES TO YOUR BRANCH SECRETARY OR THE EDITOR ADDRESSES PAGES 1 & 5

10th AWWA FEDERAL CONVENTION Sydney, N.S.W. -

11th-15th April, 1983 ,

The Convention will present 63 interesting and topical papers in ten subject groups comprising two program streams-clean and wastewater. THE VENUE, the luxurious Wentworth Hotel will provide the optimum in facilities and convenience-right in the heart of the city. SYDNEY IN APRIL, will be offering its best - viewing and dining cruises on that lovely harbour, the historic Rocks area, the Opera House, lovely seaside suburbs, sailing, golf, theatres, the beautiful environs north and south. THOSE ACCOMPANYING REGISTRANTS will be especially welcome and catered for. POST CONFERENCE TOURS will include the Hunter Valley vineyards, mining and industries. ENQUIRIES AND PRELIMINARY PROGRAMS-write the Secretary, AWWA 10th Convention, P.O. Box A232, Sydney South, Aust. 2000. WATER

SEPTEMBER 1982

CHLORINE DOSE AND 1,RIHALOMETHANE FORMATION N. H. Pilkington SUMMARY

It is prudent to control trihalomethanes (THMs) in potable water supplies, but THM control should take second priority to ensuring that the water is adequately disinfected. 100 /Lg/ L is a realistic goal which should be achievable without jncurring undue expense . Prevention of THM formation is preferable to removal. Laboratory chlorination studies on algae laden waters demonstrate that the presence of both free chlorine and precursors is required for THM formation. Thus, chlorine demand, as well as chlorine dose, must be taken into account when comparing THM formation from different waters. In addition, reaction conditions can be controlled to minimize THM formation . INTRODUCTION

The proposal of the U.S . E.P .A. to require a maximum concentration limit for trihalomethanes (THMs) in potable water supplies (U.S. E.P.A., 1976) generated much controversy in the water industry of that country. Debate on the major issues - the rationale and the value of the limit - rapidly spread worldwide. Different countries have taken different approaches for setting such limits. However, as a result of the research stimulated by the proposal, the conditions under which THMs are formed became understood. Hence, knowledge of appropriate action to enable compliance with a limit is now available. The aims of this paper are threefold: 1. To acquaint Australian readers with overseas approaches to THM legislation; 2. To comment on the desirability of a THM limit, and on methods of THM control; and 3. To use the results of laboratory chlorination studies of algae laden surface waters to illustrate some of the chemical principles involved in THM formation so that favourable conditions for their formation can be avoided. In particular, the need to minimize free available chlorine is demonstrated. TUM LIMITS History and Current Status

The THMs, of which chloroform is the most familiar example, are methanes in which three of the hydrogen atoms are substituted by halogen atoms - Cl, Br, or I, the latter being rarely found in practice. The substituting halogens may, but need not, be the same. The water industry was first alerted to the presence of small amounts of THMs in potable water supplies in 1974 by Rook in the Netherlands and Bellar, Lichtenberg and Kroner in the U.S.A., who showed that they could be formed from naturally occurring organic matter (mainly humic and fulvic acids - the compounds responsible for "colour" in natural waters) when the water was chlorinated to destroy any microbial pathogens which may be present. A national survey in America then established that the presence of these and other, potentially carcinogenic, compounds in water was widespread (Symons et al, 1976). The U.S. E .P.A. (1976) responded to protect Âˇhuman health by giving advance notice of a proposal to limit the total concentrations of THMs to 100 /Lg/L. The official announcement of the limit was made in February 1978 (U .S. E.P .A., 1978a). Simultaneously, an independent requirement to use granular activated carbon (GAC) for the control, in potable water, of synthetic organic chemicals of industrial origin was also proposed. Comments on the two regulations were requested (U.S. E.P .A., 1978b). Many respondents incorrectly assumed that GAC was required for THM control. This was not the intention, although GAC does have limited use for that purpose.

Mr Norman Pilkington is a Senior Research Scientist at the CS/RO Division of Chemical Technology, South Melbourne. 10

The U.S. water industry, which was faced with the cost of compliance with the limit, reacted strongly to the THM proposal. Over 800 comments were received (U.S. E.P .A., 1979). The major concern was the basis upon which the health effects data were being used to support the regulations. The E .P .A . was charged with acting prematurely and setting an arbitrary limit. After due consideration of the comments, the E.P .A. defended its position and formally promulgated the THM regulations on November 29, 1979 (U.S. E.P.A., 1979). Several typographical corrections followed a few months later (U.S. E.P.A ., 1980). Some minor amendments to the original proposals were conceded , but the maximum concentration limit of 100 /Lg/ L was retained. In summary, the regulations are that community water systems serving populations greater than 75,000 must commence the specified monitoring programme within one year of the promulgation date and must control THMs to less than 100 /Lg/ L within 2 years (i.e. by November 29, 1981). For systems serving populations of 10,000 to 75,000 the corresponding periods are within 3 years and 4 years of promulgation. Other countries have set different standards which range from 25 /Lg/ L in West Germany to 350 /Lg/ L in Canada (Water Research Centre, 1980). In the U.K., by contrast, the Joint Committee on Medical Aspects of Water Quality concluded that "the evidence concerning a carcinogenic risk form current levels of THM is inconclusive but that any risk which may exist is likely to be extremely small" (Zabel, 1980). Hence, they did ncit consider the removal of THMs from water to be a high priority; nevertheless, they did take the view that steps be taken to reduce the concentrations of THMs "as far as practicable in the light of other calls on resources and while retaining basic water disinfection techniques" . In Australia, no official positions have yet been taken. The Department of Health, NHMRC and AWRC (1980) may well have had trihalomethanes in mind , however, when they stated in the publication "Desirable Quality for Drinking Water in Australia" that "In certain areas some additional characteristics . .. may be of concern . The authority should give these special consider1tions if it is suspected they could impair drinking water quality" (paragraph 1-3). Further, in paragraph 1-7 (op. cit.) they recognized that future revision in respect of, for example, certain organic substances may be necessary. Discussion

Whilst there is a potential health risk from trace organics in water supplies, the greatest danger to human health from water supplies arises from. viruses and pathogenic bacteria. Hence adequate disinfection must be the primary consideration. Within this framework, however, it is prudent to keep in mind the risk from THMs and to take steps to control them . A further advantage of controlling THMs is that the presence of other halogenated organics will also be minimized. THMs represent a convenient surrogate parameter for organo-halogens because they are easily measured (by gas chromatography) and because other haloorganic compounds are unlikely to be formed during chlorination if THMs are not also liberated. As with TOC/COD/BOD correlations (Pilkington and Swinton, 1974), there is not theoretical reason to expect THM/ Total Organic Halogen (TOH) correlations, but, for particular sources, correlations will probably be found. I do not consider, however, that there is yet a defensible numerical standard applicable to all situations. The American standard does represent a convenient goal, though, even when economic factors are taken into account. Firstly, the majority of waters for which data have been published meet the 100 /Lg/L criterion even when their treatment schemes, if any, were designed without THM control in mind. To date, little information is publicly available for Australian waters, but Kimpton (1981)

SEPTEMBER 1982

WATER

has shown that Sydney's water supply easily complies with the U.S. standard. This state of affairs is probably the norm, especially in the major cities. On the other hand, in an extreme case in South Australia, where a highly coloured water is chlorinated-before being transported a long distance in an above-ground pipeline, THM values in excess of 500 Jig/L have been reported (Lane, 1981). Secondly, in many cases, THM levels can be reduced with only minimal additional expense, simply by better control of existing unit operations (especially flocculation and chlorination) or by rearrangement of the treatment scheme (e.g. moving the point of appiication of the chlorine). Such simple techniques may not be applicable in Australia because, in general, it is suspected that many of the water supplies with high THM values would currently be subjected to only the most rudimentary treatment. However, if more sophisticated treatments are installed, consideration of THM control at the design stage should not result in undue additional expense.

TUM CONTROL

COLORINA TION OF ALGAE LADEN WATERS Samples of algae-laden surface waters from three impoundments near Pretoria were chlorinated under laboratory conditions. Some chem ical water quality data are shown in Table I . The amounts of THMs formed were determined by a so lvent extraction/ gas chromatographic technique (Van Rensburg et al, 1978) . A ll reaction s were quenched with ascorbic acid (after Kissinger and Fritz, 1976) after a period of I hour. In cases where free chlorine was still present, THM formation would have continued. The data, therefore, do not necessarily represent the full potential for THM formation at the chlorine dose indicated.

TABLE 1. WATER QUALITY PARAMETERS OF ALGAE LADEN SURFACE WATERS Rietvlei

Harrbeespoort Raw

Filtered

Raw

Filtered

9.6

9.6 N.A. 4.8 45 1.2

8.5

8.5 24 6.0 38 1.2

6. 1

7.0

Roodeplaat Raw

Filtered

9.3

9.3 II

6.6

119

3.5 70

1.5 30

6 120

4.0 24 0.8

• Calcula1 ed from Chloroph yll -a valu es.

In pure culture experiments, both a lgal biomass and their exWATER

therefore primarily carried out to determine whether prechlorination, which would be required for algae removal by alum flocculation, would be acceptable from the point of view of THM formation. The results are shown in Fig. I.

200

(RP)

,(RP-F) (HBP) ~.::/...- · ( RV l

;:;<,

150

.,,........

::::::

Two basic approaches are possible for THM control: (a) Removal of THMs produced during the existing treatment scheme; or (b) Prevention of THM formation by (i) the removal of precursors before chlorination; (ii) the control of ch lorination reaction conditions; and/ or · (iii) the use of a disinfectant other than chlorine. Adsorption techniques (using GAC or specially developed resins such as Rohm and Haas' XE-340) and air-stripping are contending methods for THM removal but neither is considered to be both successful and economic in the long term. Adsorbents, especially GAC, possess low capacity for THM, compared with the competing organics normally present in waters. In addition, chromatographic effects on the column can lead to a sudden increase in THMs in the effluent, particularly for in fluents with low concentrations of THMs. Large-air-towater ratios ( > 20: I) are required for efficient stripping of low concentrations of chloroform . The other THMs are less volatile, and, thus, are even more difficult to remove by air-stripping . The preferred alternative is prevention of THM formation. Based on a n overall consideration of cost, efficiency and maintenance of a residual disinfection ability, ch lorine continues to be the best choice of disinfectant. Hence, control of TH Ms by control of precursor concentration and chlorination conditions is the optimum route. Some of the chemical principles involved are discussed below, and are based on experimental wcirk that I undertook wh ilst on a secondment to the National Institute for Water Research in South Africa.

pH Colour (Pt-Co units) TOC (mg/ L) Chloride (mg/ L) Bromide (mg/ L) Ch lorophyll-a (ug/ L) AlgaeDry weight• (mg/ L) Wet weight• (mg/ L)

tracellular products have been shown to be THM precursors (Hoehn

et al, 1980; Oliver and Shindler, 1980). The experiments were

c,,

3:::E

I I

100

:I:

~ '

I I

I •

,I,'

,•

I ' ' .:: I '. '

'/0 ,,,,'

_,1:

.w· It

;§

,. ,

~,, ,.-"'.,,, -· ,."'_ .,, . .. ·

KEY •········· Hortbeespoort ( HBP) • - · - Rietvlei ( RV) • - - Roodeploot ( RP) o---- Roodeploot-filtered (RP-Fl

o-------~-----~ 0

10 Chlorine dose (mg/I)

Figure 1. THM formation as a function of chlorine dose (1 hour reaction period).

As di scussed in more detail in an earlier paper (Pilkington and van Vuuren , 1981), the results showed that, at chlorine ,doses of 5- 10 mg/ L, simi lar amounts of TH Ms were formed whether the algae were present during chlorination or were removed beforehand by a physical technique. (In the laboratory , filtration through a 0.45 Jim membrane was used). Thus, the a lgal biomass did not significantly contribute to THM formation, and prechlorination for a lg/e removal did not produce more THM s than wou ld have occurred in any case for these waters. The soluble precursors on their own yielded THM values in excess of 100 Jig/ L. In the case of the Roodeplaat samp le, the sample with the highest a lgal content of the three (Table I), chlorination of the raw water or doses above 10 mg/ L yielded more THMs than did the filtered sample. However, the contribution of algal biomass to THM formation was still relatively minor. For example, at 20 mg/ L chlorine dose, the increase in THM formation in the presence of the algae was only 15% (Fig. I). Alth ough it was observed during the reaction that the green colour of the algae was lost, chlorophyll cannot be the major source of algae-derived precursors. Morris and Baum (1978) found that at a chlorophyll concentration of 117 mg/ L (or 15 times that present in this example) only 56 Jig of CHCI, per litre of water were produced at a ch lorine dose of 40 mg/ L with a reaction time of 100 hours at pH 7. For both the Hartbeespoort and Rietvlei samples . similar amounts of THMs were formed from the filtered and unfiltered samples even at ch lorine doses as high as 20 mg/ L (Pi lk ington and van Vuuren, 1981). Chlorine Demand and THM Formation The effects of ch lorine dose on THM formation can be explained in terms of the need for the presence of free chlorine in order for THM s to be formed. This is readily shown in Fig. 2, in which the data in Fig. I are re-plotted against the measured free ch lorine value at the end of a one hour reaction period . Until sufficient chlorine is added so that there is free chlorine present during at least part of the reaction period , significant formation of THMs does not occur.

SEPTEMBER 1982

200

KEY 150

OI ~

:::c::

/,,,' '

I-

Algal pond secondary effluent

Filtered algal pond effluent

--·

-·· :ii""" ~=--. -::-:-·

100

I '

~-I r

:::c:: I-

•·······-

•-·•--

KEY

I-

Hartbeespoort Rietvlei I

Roodeplaat

?11:.

0 0

100

Chlorine dose (mg/I) Figure 3. Chlorination of secondary effluent from an algal oxidation pond, Daspoort, Pretoria (1 hour reaction period).

10 20 0 Free Chlorine after I hour reaction period (mg/I) Figure 2. THM formation vs measured free chlorine (1 hour reaction period).

The requirement that the ch lorine must be available as free ch lorine has not been sufficiently emphas ized in the past. In turn, the chlorine demand of the water is an important parameter since the same chlorine dose applied to different waters will produce different free ch lorine values. Surface waters such as those discussed above do not normally have a significant immediate chlorine demand, but this fac tor can be important in other types of waters. For example, significant formation of THMs from the filtered effluent of an algal oxidation pond used for the treatment of raw sewage does not occur below chlorine doses of Ca . 15 mg/ L (Figure 3). In this case, most of the demand will be from ammoniacal nitrogen, which consumes approximately 8 mg of Cl, per mg of NH , - N . In the unfiltered sample, the organic matter and microorganisms also co ntribute to a chlorine demand via reactions such as disinfection, oxidation and the formation of other chlorinated organics . Thus, at chlorine doses up to about 60 mg/ L, less THMs are formed from the unfiltered than from the filtered sample because of the higher chlorine demand · and hence lower free chlorine value of the raw sample at the same chlorine dose . As the chlorine dose is increased beyond the immediate chlorine demand, the precursor concentration takes over as the limiting factor to THM formation. Thus, in the case of the Hartbeespoort and Rietvlei samples, the precursor concentration is limiting when the free chlorine concentration exceeds 10 mg/ L, whereas, for the Roodeplaat sample, there is still a rapid increase with chlorine dose in the a mount of THMs produced at free chlorine values near 20 mg/ L (Fig. 2). Similarly, the algal pond effluents show that precursor concentration is not limiting at free chlorine values as high as 40 mg/ L. Odour formation during chlorination

During the chlorination reactions for the algae-laden surface waters, it was observed that at chlorine doses up to 5 mg/ L, a foul odour was formed in the product water. The odour diminished as the 12

chlorine dose was increased to 10 mg/ L, and, at 20 mg/ L added chlorine, there was no noticeable malodour in the product water. Presumably, the decaying algae release foul- smelling compounds which are then oxidized or otherwise removed if sufficient ch lorine is present. This result demonstrates the care with which water chlorination must be carried out. Sufficient chlorine must be added not only to disinfect the water, but also to overcome any taste and odour taints produced, whilst , at the time, the amount added must be minimized to avoid problems such as THM formation. , Assessment of THM formation potential for different water sources

The major prerequisite for THM formation is the simu ltaneous presence of both free chlorine and appropriate precursors . However, th e reaction condition s can also influence the amount of THMs formed from the same water at the same chlorine dose. These effects have been reviewed by Trussel and Umphres (1978). In summary, THM yields can be minimized by avoiding high pH, high temperatures and long reaction times. As discussed above, the primary aim of chlorination, i.e. adeq uate disinfection, must not be lost sight of. The THM formation reaction is selective for bromide ions (Pilkington and van Vuuren, 1981), so waters containing even sma ll amounts of those ions (say, > 0.2 mg/ L) can yield substantial quantities of bromine containing THMs. Gross parameters such as colour or TOC should be used with caution when THM formation potential is being assessed. They a re satisfactory in a general sense, but , strictly speaking, there is not a true correlation. This is demonstrated by the results presented in Table 2 for the chlorination of a number o~ waters, including two secondary effluents from sewage treatment processes. The results are quoted at a constant one hour free chlorine value of IO mg/ L to eliminate ch lorine demand as a variable. In the case of TOC, the lack of correlat ion is not unexpected. Firstly, THM precursors would represent only a sma ll proportion of the total TOC present. Secondly, even those organics which are precursors will vary in their reactivity and THM yield. Hence, as well as their concentration, the type of organics must also be taken into account.

SEPTEMBER 1982

WATER

TABLE 2. TOTAL THMs PRODUCED FROM VARIOUS WATER SOURCES AT I HOUR FREE CHLORINE VALUE IO mg/ L Sample "As Received"

Water Sample

Hartbeespoort Dam Roodeplaat Dam Rietvlei Dam Humus Tank Effluent Algal Oxidation Pond Effluent

Filtered Sample Colour (Pt-Co units)

TOC (mg / L)

TTHM

(µg/L)

TOC (m g/L)

6.1 6.6 7.0 7.5

150 170 155 101

5.0 4.0 6.0 7.3

11 24 24

140 140 145 145

113

4.7

Institute for Water Research, C.S.I.R., South Africa and by the South African Water Research Commission, which enabled.me to spend a period at the N.I.W .R. laboratories in Pretoria. Mr A. J. Hassett and Mrs I. Coetzee ass isted with some of the THM analyses and extractions.

TTHM

(µg / L)

The Rietvlei sample contained the least algae but the most colour (Table I) whilst the Roodeplaat samp le was low in colour but had the highest algal population. Humic and fulvic acids, which are the species mainly responsib le for the colour of surface waters, are known to readily produce THMs when they are chlorinated in aqueous solutions (Rook, 1974; Trussell and Umphres, 1978). Thus, at very low chlorine doses, more THMs were produced from the Rietv lei water than from the Roodeplaat samp le, but the rate of increase with chlorine dose levelled off quickly as the precu rsors were consumed. The consumption of ch lorine for disinfection was also a contributing factor to the low THM production from the Rocideplaat sample at low chlorine doses, because of the high algal population of that sample . The algal extra-cellular products wou ld also be expected to be less reactive than colour bodies towards THM formation. Thus, high chlorine doses were required before the increased THM formation potential of the Roodeplaat sample was realized in practice. CONCLUSIONS

The American limit of 100 µg / L is a realistic goal for the control of THMs in potable water supplies. Both precursors and free chlorine are required for THM formation. THM formation can therefore be minimized by reducing precursors (e.g. by floccu lation or by absorption) before the ch lorine is applied, or by reducing the free chlorine by the use of just sufficient chlorine for the required disinfection, or by the use of an alternative disinfectant . Chl orination reaction conditions can also be controlled to minimize THM formation (e.g. low pH , low temperature, short reaction time) . However, reduction of THMs should take second priority to the microbiological quality of the fin ished water. Because free chlorine is needed for THM formation , the chlorine demand of the water is an important consideration when the amounts of THMs produced from different waters are compared at the same ch lorine dose . ACKNOWLEDGEMENTS

REFERENCES BELLAR, T. A., LICHTENBERG, J . J . and KRONER, R. C. (1974) . J. Amer. Water. Wks. Assoc. 66 (12) 703-706 . DEPARTMENT OF HEALTH, N .H .M.R .C. and A.W.R.C. (1980). 'Desirable Quality for Drinking Water in Australia'. Australian Government Publishing Service, Canberra. HOEHN, R. C., BARNES, D . B., THOMPSON, B. C., RANDALL, C. W., GRIZZARD, T. J. and SHAFFER, P. T . B. (1980). J. Amer. Water Wks. Assoc., 72 (6) 344-350. KIMPTON, C. D. (1981). Preprints 9th Federal Convention, Austr. Water and Wastewater Assoc., Perth, April, 1981. pp 12.22-12.24. KISSINGER, L. D. and FRITZ, J. S. (1976). J. Amer. Water Wks. Assoc., 68 (9) 435-437. LANE, D. J. (1980). 'The future quality of South Australia's water supplies'. Paper presented at 50th ANZAAS Congress, Adelaide, May 1980. MORRIS, J . C. and BAUM, B. (1978) . 'Water Ch lorination: Environmental Impact and Health Effects' (Jolley, R. L. , Gorchev , H. and Hamilton , D. H., Eds.), Volume 2, Ann Arbor Science, Ann Arbor. pp 29-48. OLIVER , B. G. and SHINDLER, D. B. (1980) . Env. Sci. and Technol., 14 (12) 1501.-1505. PILKINGTON, N. H. and SWINTON, E. A. (1974) . Water , 1 (2) 19-21. PILKINGTON, N. H. and VAN VUUREN, L. R. J . (1981). Preprints 9th Federal Convention , Austr. Water and Wastewater Assoc ., Perth, April, 1981. pp 17.16-17 .22. ROOK , J . J . (1974). Water Trtmnt. and Exam., 23 (2) 234-243. SYMONS, J. M., BELLAR, T. A. , CARSWELL, J . K., DE MARCO, J., KROPP, K . L., ROBECK, C. G., SEEGER, D. R., SLOCUM, C. J ., SMITH, B. L. and STEVENS, A. A. (1975). J. Amer. Water Wks. Assoc., 67 (11) 634-646. TRUSSELL, R. R. and UMPHRES, M. D. (1978) . J. Amer. Water Wks. Assoc., 70 (11) 604-612. U.S . ENVIRONMENTAL PROTECTION AGENCY (1976). Fed. Register, 41 (136) (July 14) 28991-28999. U.S. ENVIRONMENTAL PROTECTION AGENCY (1978a) . Fed. Register, 43 (28) (Feb. 9) 5756-5780. U.S. ENVIRONMENTAL PROTECTION AGENCY (1978b) Fed. Register, 43 (130) (July 6) 29135-29150. U.S. ENVIRONMENTAL PROTECTION AGENCY (1979). Fed. Register, 44 (23 I) (Nov. 29) 68624-68707. U.S. ENVIRONMENTAL PROTECTION AGENCY (1980) . Fed. Register, 45 (49) (Mar. 11) 15542-15547.) VAN RENSBERG, J. F. J., VAN HUYSTEEN, J. J. and HASSETT, A. J. (1978). Water Res. , 12 (2) 127-131. WATER RESEARCH CENTRE (1980) . Papers ,and Proceedings W.R.C. Seminar on Trihalomethanes in Water, Lorch Foundation, 16 and I 7 January, 1980. (Publ. by W.R.C., September, 1980) . p. 246. ZABEL, T . F. (1980) . Papers and Proceedings W.R.C. Seminar on Trihalomethanes in Water, Lorch Foundation, 16 and 17 January, 1980. (Publ. by W.R.C. , September 1980). pp 175-210.

I am grateful for the financial assistance, provided by the National

'WATER' NOTICE TO SUBSCRIBERS

SUBSCRIPTION INCREASE Rising costs have forced the Association to increase the subscription rates for the journal. Commencing with the March issue for 1983 rates will be: Per issue: $2.50 Aust. Per annum: $10.00 Aust.

Rates include surface mail to all countries.

WATER

Mail requests to: The Editor 7 Mossman Drive Eaglemont, Vic. 3084 SEPTEMBER 1982

All subscriptions conclude with the December issue.

TECHNICAL INTERESTS NATIONAL WATER RESEARCH COUNCIL

DEPART MENT OF SCIENCE AND TECHNOLOGY

The Government's response to submissions from th e A WRC, CSIRO and Bureau of Mineral Resources as announced by the Minister for Natural Development and Energy, Senator Carrick is summarised below. A National Water Research Council will be establi shed with terms of reference including: • advise on goals for water research in A ustralia; • maintain a continuing overview of water research in Austra lia with a view to developing an overall balanced national water research effort; • assess on a continuing basis national needs and recommend national researc h priorities; • recommend on funds necessary to implement a balanced program of research and development; • eva luate appropri at e research and demonstrati on programs and projects, and recommend funding for indi vidual projects; and • advise on an effective program of technology transfer from the research and demonstration sectors to operati ng authorities and users. T he Governmen t acknowledges community concerns justifying upgrading of water research in A ustralia reflecting increased competit ion - between urba n, industrial , agricultural and recreational demands; increasing pressure on existi ng supplies from maj or new energy related developments; salinity problems of the Murray Valley and Wes tern A ustralia an d other aspects of water supplies. The States have promised full co-operation in this important new initiative. Membership will be considered shortl y and the Council should quickly co ntribute expert advice to the Government on research needs, priorities and programs. Technical and administrative support will be provided by the Department of National Development and Energy. Initial allocat ion this year for research proj ects will total $400,000 in addition to ongoing projects in the current triennial program of the A WRC. Co-ordination of water research within Commonwealth Agencies will be improved. T he Ministers for National Development and _Energy and for Science and Technology wi ll have joint roles in the formulation and direction of research programs and wi ll be kept advised by a Water Research L iaison Committee. The Government believes that recent CSIRO re-organisation in the areas of water research and the above proposals will enable an orderly expansion of established research organisations which will be more effecti ve than the establishing of new institutions. T he Government is determined to ensure that water supply difficulties of quantity and quality do not constrain national development.

BILATERAL SCIENCE AND TECHNOLOGY AGREEMENTS

Limit ed funding is available to facilitate interaction betwee n agencies in Au s tralia and variou·s countr ies. The activities li sted below wi ll receive priority but others will be c onsidered .

India/Australia: agricu ltura l sciences, so lar energy, earth sciences . FRG (Germany)/Australia : energy resea rc h (coal and so lar energy) , marin e science and tec hnology , Antarctic re search . Japan/Australia: app li ed biology, app lied physic s, earth sciences, polym er chemistry , applied science/engineering, Antarctic research , marine geology and geophysi cs . Mexico/Australi a: plant g·ene·tics , rangeland managem ent , cattle breeding ; energy-coal, solar, biomass conversion; engineering-meta llurg y, materials ; oceanography, applied physics. China /Australia: animal production and husbandry , plant production , arid and se mi arid region deve lopm ent , environmental sciences, energy sources , Antarc tic res earch , medical sc ience and hea lth , meteorology ; deve lo pment and utilisation of non ferrous metals and min eral resource s; engin eering and architecture . US/Australia: no form al priority areas. Activity Commencement is July 1st to Dec. 31st, 1983. Application Closing Date: Oct. 1st, 1982. Enquiries to Program Manager, Bilateral Science and Technology Agreements, P.O. Box 65, Belconnen, ACT 2616 ((062) 64 1158).

PIPE FRICTION SEM INAR 2 p.m. November 11 - Melbou rne The Austra li an Pump Manufacturers ' Association Ltd . will ho ld a Technica l Seminar in co njunction with th e ·1aunch of it s latest publication, th e 'A PMA Pip e Frict io n Hand bo ok ' at the Leonda Convention Centre , 2 Wa ll en Road , Hawth o rn , Me lbourne. Speakers wi ll in c lud e: N. T. Cowper, Slurry Systems Pty. Ltd .; A. Bro w n, State Ri ve rs and Water Supply Commission; and A. Long staff , G. H. & D. Pt y. Ltd. Th e seminar wi ll be .a n important SEPTEMBER 1982

and informative event for all involved in pipeline design , appl ication and usage . The Pipe Friction H.andbo'ok provid es th e first standardised set of pipe friction tables as a practical reference for al I people associated with movement of materia'ls by pipeline. Further information: APMA National Secretary , P.O . Bo x . 817 , Canberra City , ACT 2,600 or phone Greg Crowther (06 2) 49 6360, 49 6364 .

.....

i I

. . ...

ENGINEERING .. EXCELLENCE AW A"RD INSTITUTION

oF' ENGiNEERS·AusT.

VICTORIA Twenty-two impressive entries posetl a problem to the jury panel adjudid1ting aliocation of the 1982 awards . The panel, Chairman John L. Grigg and members John Hill, Harold Richanisand Dr. Howard Worner finally awarded two 'Excellences' and three 'Highly Commended'. Recipients were: • Exce llence Award to ' Aeronautical Research Laboratories, Department of Defence, for its research and development of a boron fibre reinf6rced piastic patching technique as employed for the repair of cracked metal components on RAAF Mirage III aircraft. • Excellence A~rd to Varian Techtron Pty. Ltd. for the novel graphite furnace atomiser which is the latest development incorporated in its series of atomic absorption spectrophotometers. • Highly commended the Melbourne and Metropolitan Board of Works for the design of the Winneke Reservoir which stores the natural water resources of the lower Yarra River to supplement Melbourne water supplies while minimising environmental impact. • Highly Commended Repco Research Pty. Ltd. for the design and development of an advanced 350 tonne hydraulic blanking p ress utili sin g the adva ntages of hydraulics and microprocessor co ntrol. • Highly Commended W il so n Elec tri c Tra nsformer Com pan y Pty. Ltd. for the integrated design of the firm's new electric transformer plant at Wodonga. These engineering achievements reflect the Profession's and community co ncerns for resource preservation, safe and pollution free li ving and enviro nment and value for money speak. T he judging left the panel with high opinions of the technical standard s and innovative aspects of engineering in Vicloria. WATER

TECHNICAL INTERESTS (cont'd) MINE WATER PROBLEMS NEW ASSOCIATION The International Mine Water Association held its first International Conference in Budapest in April last with an attendance of over 300 from some 20 countries. President of the Executive Council of IMWA is Prof. C . 0 . Brauner (Canada), Vice-President is Prof. R. E. Williams (U.S .A.), Australian representative on the Council is Mr. S. Hancock, Melbourne. The main objectives of !MW A are: • improved exploitation of mineral resources consistent with desirable standards of safety against water hazard; • increased protection of the environment against mine drainage and related activities; ~ improved uti lization of mine water; and • improved technology and economy of mine drainage and control operations. The major activities of !MW A are intended to be: • the organization of conferences at regu lar intervals; • the organization of working groups ahd commissions on matters of common interest and concern; • the publication and dissemination of technology to members throughout the world. Membership is sought from Mining Companies, Universities and relevant Government Departments. Enquiries should be addressed to : Prof. Dr. R. Fernandez Rubio , Secretary General, Int . Mine Water Association Granada, Spain or Mr. Stephen Hancock: Australian Groundwater Associates P/ L, 36 Wellington St., St. Kilda East, 3184.

INSTITUTION OF WATER ENGINEERS AND SCIENTISTS

SYMPOSIUM AND EXHIBITION MANAGEMENT AND APPLICATION OF MICRO-ELECTRONICS IN THE WATER INDUSTRY DEC. 2nd-3rd-London Program includes: corporate, motivating and manufacturers views; practica l aspects in process industry control, computer aided plant operation, data acq uisition, management and trai ning and the Government view . Enquiries to: The Secretary, Inst. of Water Engineers & Scientists , 31 High Holborn , London WC IV-6AX , U.K. WATER

CALENDAR 1982-83

Nov. 14-19, Capetown, S. Africa

18th Int. Conference on Coastal Engineering.

Sept. 13-17, Philadelphia, U.S.A.

Nov. 29-Dec. 4, Birmingham, U.K.

3rd Int. Filtration Congress.

1982 Public Works Exhibition & Congress.

Sept. 14-16, Reading U.K.

Nov. 30-Dec. 2, Canberra, Australia

Int. Conference on flow induced vibrations in fluid engineering.

Symposium on Prediction of Water Quality (Aust. Ac. of Science).

Sept. 14-16, Southampton, U.K.

Dec. 2-3, London, U.K.

Shoreline Protection . Sept. 19-Oct. 1, Denver, U.S.A.

Int. Seminar on Water Systems, Management, Operation & Maintenance. Sept. 20-24, Eastbourne, U ..K.

1982 Meeting, Inst. of Water Pollution Control. Sept. 21-23, Berne, Switzerland

WHO Int. Symp·osium on hydrological research basins and their use in water resources planning . Sept. 21-23, Southampton, U.K.

Inst. Water Engineers & Scientists Symposium, Microtechnology Dec. 5-8, Nashville (Ten.), U.S.A.

Water Quality Technology Conference.

1983 Jan. 16-19, New York, U.S.A.

Meeting of Water Pollution Control Federation. March, Queensland, Aust.

Conference on Coastal Engineering.

Boundary Element Methods 1n Engineering.

March 1-4, Mexico City

Sept. 22-24, Coventry, U.K.

Aqua Mel,-'.83 Int. Water Technology Ex and Conference (Water Decade 1981 / 90) .

Int. Conference on Hydraulic Modell ing of Civil Engineering Structures.

March 7-10, Melbourne, Vic.

Sept. 27-Oct. 2, Varna, Bulgaria

Int. Symposium on computation of groundwater balances (UNESCO). Sept. 27-30, Toowoomba, Q'ld. Aust.

Workshop on non-po int sources of pollution in Australia. March 21-25, Darwin, N.T.

Agro-Research for Australia's Semi-Arid Tropics.

Symposium on Rural Drainage in Northern Australia.

March-April, Queensland, Aust.

Sept. 28-Oct. 1, Asilomar, Cal., U.S.A.

April 11-15, Sydney, Aust. A WWA 10th Federal Convention .

Impacts of Limited Water for Agricu lture in the Arid West.

Eng. Conference

op Tunnelling.

May 2-6, Noordwijkerhout, N'lands Oct. 3-8, St. Louis, Mo., U.S.A.

Water Po ll ution Control Fed. Conference. Oct . 4-10, Lelystad, Netherlands

Polders of the World, Int. Symposium and Exhibition. Oct. 10-14, San Francisco, U.S .A.

18th American Water Resources Conference.

Int. Symposium on Methods and Instrumentation for the Investigation of Groundwater Systems. May 9-11, Perth, W. Aust.

53rd ANZAAS Congress. May 16-20, Brisbane, Queensland

Annual Scientific Meeting, Soc. of Microbiology. June 5-8, Florence, Italy

Oct. 13-15 , Rotterdam, Netherlands

Delta Barrier System.

1983 Conference of Int. Federation of Consulting Engineers.

Oct. 17-Jan. '83, Haifa, Israel

July 15-26, Hamburg, Germany

Master of Science Course in Engineering Management of Water Resources. Oct. 19-21, Canberra, Aust.

Energy I 982 Conference. Nov. 2-5, London, U.K.

London Civil Eng. Construction Show and Conference. SEPTEMBER 1982

Int. Symposium and Workshop on Hydrological Application of Remote Data Transmission . August, Newcastle, N.S. W.

Computers in Engineering Hydraulics and Fluid Mechanics. August 14-19, Perth, W. Australia

Solar World Congress. 15

WATER- PRISTINE PURE! Dr. W. N. Sloane Dr. W. N. Sloane is Deputy Director, Public Division (Clinical Services) of the Health Commission of Victoria gave rh is 'keynote' speech to the Water Research Foundation in Melbourne on September 10th. It is a great ho nour to be asked to make the keynote speech to launch th e United Nations International Drinking Water Supply and Sanitation Decade upo n a largely unheeding world . I venture to suggest that the man in the street knows nothing o f this concept and cares even less. To him , water , especially if it comes from a tap , is a substance of pristine purity: the occasio ns when he has been wrong fill books such as those published by the U.S. Centres fo r Disease Control. T he same man in the street a lso knows th at water served abroad (except in aeroplanes and good hotels) is suspect , and can cause disease in clean living white men , but not of course in the natives who are used to drinking such fl uids. That he is o ften wrong is shown by the numerous clean living white men who return to this country with bowel in fections and/ o r infes tations, as well as other more social diseases. I am sure that other speakers will tell you what happens when the quality of drinking water is low. Note that word " quality": that bas-ically is what this Decade is about. Quality implies that there is some kind of sta ndard against which the water in question is meas'u red . Now, how do we set such standards? Ob·vio usly there must be a "beneficial use" of such water, and as we are discussing drinking water, it o bviously implies that the water must be pleasant to drink , a nd more importantly, the drinker must not be made ill . So, we set our q uality standard in such a manner as to make the water safe and pleasant to drink . It sounds simple-it isn't. Many nations have set quality standards, and in Australia, we have until recently tended to follow such overseas standards as those set by the U.S. Public Health Service or the World Health Organisation . Now, Australia has its own set of standards, titled " Desirable Qualit y for Drink ing Water in Australia", jointly put o ut by the Natio nal Health and Medical Researc h Council and the Australian Water Resources Counci l. These two bodies set out separately to fix standards, and then wo ke to the fac t that it would be more sensible to agree among themselves upon levels, and then jointly publish with the authority of both bodies. T he scheme wo rks well and several people are on both committees . Funnily enough, despite the emphasis upon bacteria, there 1s no bacteriologist upon either and if you thin k that this is a typical Australian bureaucratic stupidity, let me point o ut that as fa r as I can judge there was no bacteri ologist upon the W.H .O. working part y. The fu nction o f these Committees is to produce standards and the method , as far as Australia is concerned , is very much a matter of applying overseas work. There is very little purely Australian research which coldly and scientifically sets out to develop a standard fo r this country. We are too small a nation to devote sufficient resources to the job , and I ask what is so special about Australians that we need our own special standards? Yet, there are diffe rences in Australia. We are lucky in that by and large our rivers do not receive massive sewage discharges as do the rivers of Europe and America. We do not seem to have the large q uantities of chemical poisons which periodically fa ll or are washed into waters abroad . Also, we have in many places the fa mous water tank s whose use may mask the dangers of some of o ur water supplies . Also o ur relative isolati on and high hea lth standards has meant that we no longer have the faecal-oral diseases which afflict oth er nations. But this is now 'changing. We are accepting Asian migrants, our populati ons are most mobile and London is now 28 hours away when in my youth it was six weeks. Ou r young no longer holiday at Mordialloc bu t in exotic overseas venues often noted fo r the availability of drugs a nd enteric in fec tio ns. Ten years ago , we would have scoffed at the thought that cholera could be reintroduced , and now the o rganism is often fo und in Northern Australian waters . Recently, th e World Health Organisati on produced in dra ft fo rm a new series of water quality standards. T hese appear to be all embracing and deal with : • Biological aspects of water • Organic substances quali ty • Aesthetic aspects of drin king • Microbiological aspects of water water quality • Radiological examinati on of • Health related inorgani c condrinking water stituents • Application o f the guidelines fo r drin king water quality T he fi rst six will be produced as Document A-the guidelines and Document B- the justificatio n and background . Both documents are very well written and most interesting to read .

T he _W. H.O. experts (who varied from Document to Document) are not afraid to say, fo r example-" long term ingestion of Barium from drinking water is not considered a health hazard " and again " there is insufficient information to recommend an action level for Asbestos in drin king water" . Document B for inorganics discusses 17 water constituents under the headings: •

Summary, giving the action level eg. Cyanide 0.1 mgm/ L. • General Descri ption (a) Sources (b) Occurrence in water • Routes of exposure (a) Drinking water (b) Food (c) Air i A mbient ii Industrial iii Cigarette smoking

taJ Relative significance of

the different routes of exposure • Meta bolism (a) Ingestion (b) Absorption • Hea lth effects (a) Ingestion (b) Inhalation (c) Epidemiological studies • Literature References

As I have said,. these are magnificent productions, giving a Cooks Tour of each subJect. When published, they will be invaluable works of reference fo r which we all should have use. You may think that now W. H.O . has spoken , there is not hing left to say-no more water quality criteria to write. Well you are wrong. Let me tell you of a few more criteria which I feel we could observe with advantageDES IGN: I know of one small country tow n which is used as a holiday resort by fi shermen and water sports enthusiasts. T he town's water supply comes from the local river which contains, besides water, the run off . f:om the local paddocks containing the usual animal faeces, pes uc1des etc. The water, plus additives, is pumped direct fro m the river into the reticulati on witho ut treatment. Small wonder th at the water exceeded the W. H. O. microbiological standards 100 per cent of the ti me and that Pseudomonas organisms were fo und in the reticulated water. ~Al1'.'TE NANCE: A slightly larger country town well known in Victorian hi story pumps from a local creek into a reservoir. Whatever good 1s done by the resultant retention is somewhat negated by the run off into the reservoir from pastures and drains during heavy rain . Again , all samples fa iled W. H .O . microbiological criteria, 92 per cent continued E. coli, and in addition Salm onella have been fo und, but it cert ainly saves in pumping costs! WATER T REATMENT : Th ere are some Trusts in Victoria who save on chlorine costs by not ordering any. We h~ve looked at one Victorian supply where the chlorinator was corroded solid . Funnily enough, a local food fac tory was logging chlorine resid uals in the water, a miracle somew hat analogous to the changing of water into wine at Cana. To be fa ir, on_e cannot.really blame Water Trusts if they don' t use the o bvio usly mfe n or ch_I on ne sold today. There a_re so many chlorinated supplies which have hi gh bacterial counts and fa il to meet W.H .O . criteria that it must be a fa ult of the chlorine-they couldn ' t all be poor operators, could they? What do these examples show us? l feel that _there must be a watchdog organisation, and moreover, a watchdog with teeth . Don ' t rely upon the Healt h Commiss ion. Its only legal power is to close a supply. It has power to order flu oridation to protect teeth , but no power to order chlorination to protect health . Why should some people- drin k inferior water? I propose that there should be .a small water quality orga ni sation set up within the Water Ministry; 11 should have both public health and engineering ex pertise and the responsibilit y of raising the quality of water reticulated in Victo ria. It should have free access to a competent laboratory and sho uld h_ave i_ts own sampling staff (who would sample unannounced) as I consider It wrong in pnnc1ple that the supplier also does the sampling. It should have a small assessment and advisory team with members fro m both disciplines and with the task of raising the perfo rmance of trusts . And l_astly, it sho uld have the power to compel Trusts to improve supplies 1f all other met hods of persuasion fa il : perhaps it sho uld have a direct lin k with T reasury. Gentlemen , I commend to you the United Nations In ternational Drinking. W_ater an_d Sa nitation Decade. Perhaps some of you will get involved in 1mpro~ing the water supplied in developing nati ons, as Victona ns have done in the past. I wish you every success. But if you decide to stay home, I th ink you will agree that there is an awfu l lot of work to do in Victoria to better the quality of the water we drink .

SEPTEMBER 1982

WATER

PLANT AND EQUIPMENT KENT INSTRUMENTS (AUST.) FLOW PRODUCTS CATALOGUE A new 20-page catalogue published by Kent Instruments (Australia) Ply. Ltd. describes the extensive Kent range of Flow Products for industrial, scientific and research applications. The range includes electromagnetic flowmeters, differential -type pressuretype flowmeters, mechanical water and oil meters, variable-area meters , turbine meters , vortex meters , rotary shunt meters , open-channel flowmeters , flowrate controllers, flow alarms and a wide range of associated products. Also included in the catalogue are details of the calibration service that is available to all flowmeter us e r s throughout Australia from the NATA registered flowmeter calibratio n laboratory at th e Kent Caringbah , N.S.W. plant. Copies of the catalogue are available, free of charge, from the Marketing Department, Kent Instruments (Australia) Ply. Limited, P.O. Box 333, Caringbah, N.S.W. 2229 or from any Kent Branch Office throughout Australia .

CHLORINE GAS DETECTOR ADDITIONAL SAFETY The series 1030 chlorine gas detecto. from Capital Controls Co. is a compact, electronic instrument designed to sense chlorine gas, detect its presence, and initiate a warning and/or alarm signal.

Ill

TOTAL ORGANIC CARBON ANALYZER A new total organic carbon (TOC) analyzer which will measure organic pollutants in river and lake water, as well as industrial waste and sewage water, has been released by the Scientific Group of CIG Medishield Ramsay of North Ryde, New So1,1th Wales.

The Model TOC-10B Analyzer , manufactured by the Shimad z u Corporation of Japan , has been designed for laboratory use and features a meas uring range adujustable between 0-1 0 mg/litre and 0-4000 mg/litre and a linearizing circuit incorporated in the infrared gas analyzer to ensure excellent lin earit y. TOG determinations require only 2-4 minutes as against two hours for COD tests and five days for BOD 's.

MONO MUNCHER SOLVES SEWAGE BLOCKAGE PROBLEMS The Mono Muncher represents a new approach to sewage and waste water comminutio n/macerat ion processes. It represents what may be classed as a ~i~e.di splaoemeot dlsi otegca_t_o_r.~n

Basically, the machine consists of two parallel shafts fitted with an in termeshing series of cutters. The two shafts rotate at different speeds, which encourages a tearing action at the nip contact point , permitting the machine to make easy work of such diverse materials as nylon , plastic, paper, cloth , tin cans , wood etc . Extra tough objects are ejected and the Muncher shuts down sounding an alarm . , Further information from: Mr. D. Dawson, Mono Pumps (Aust .) P/L, P.O. Box 123, Mordialloc 3195.

* I * *

SILENCED PACKAGED BLOWER SETS Godfrey Engineering now offer a rang e of Roots type blower sets operating at 80dBA or below , test readings taken at 1 metre . The Holmes SIPAC 80 range feature specially engineered acoustic housings that fully enclose both motor and blower. They are designed to meet th e increasing ly stringent requirements of Environmental and other Authorities.

DURAMIT PULSATION FREE DOSING PUMP This low capacity pump now available from ProMinent & Fluid Controls has maximum capacity of 1.4 L/h against a maximum pressure of 6 bar with capacity adjustable to 10 per cent of maximum.

.â&#x20AC;˘ ! j

-1

:â&#x20AC;˘J

..,!

I '

The gas detector consists of an electronic instrument control and circuit box and a solid-state sensor, remotemounted at the desired detection point . Separate alarm and warning circuits provide back-up alert in the event of a chlorine leak. For further information: Acromet (Aust .) P/L, 14 Winterton Rd., Clayton, Vic. 3168 (Ph. 544 7333). WATER

Capacities range fro m 100 to 8UO m3/h at pressures up to 11 5 kPa. The smallest unit requires 2 m2 of floor space, the largest , 6.5 m2. For information: Godfrey Engineering P/L, Mathews Ave , Airport West, 3042. SEPTEMBER 1982

The Duramit is a pulsation free dosing pump suitable for liquid chromatography and simi lar purposes. It has an inbuilt pulsation dampener with the necessary adjustments for accurate and repeatable dosing . Information from: ProMinent & Fluid Controls P/L, 54 Frenchs Rd ., Willoughby 2068 and 21A Shierlaw Ave ., Canterbury 3126.

INTERMEDIATE SEDIMENTATION WITH TWO-STAGE BIOLOGICAL FILTERS K. J. Hartley SUMMARY · Comparative tests were conducted at the Gatton Wastewater Treatment Plant to determine• the performance of a two stage biological filter system .with and without intermediate sedimentation. The plant comprised a plastic media primary filter followed by a rock media secondary filter and treated a predominantly domestic wastewater . Remo,val of BOD was found to be the same whether intermediate sedimentation was provided or not, but humus .sludge production was greater with intermediate sedimenation. Nitrification efficiency was better when intermediate sed imentation was operating, but whether this was a result of the process configuration or of the higher BOD loadiong prevailing at that time is uncertain . No ponding of the secondary filter at Gatton had occurred during• five years of operation without intermediate settling, but this could have been a problem at lowe'r ~Y,draulic loading rates . BACKGROUND

The omission of intermediate sedimentation between two stage biological filters is reported to have little effect on the overall performance of systems treating domestic strength wastewaters (WPCF and ASCE,,1977 and Pike, 1978) but actual data are scarce. Ponding of a secondary filter has been reported (Hambleton and Kirby, 1974) a nd probably for that reason many two stage systems incorporate intermediate solids removal. In 1976 the Gatton (Queensland) Wastewater Treatment Plant was upgraded by the addition of a plastic media primary filtei.ahead of an existing rock filter. Intermediate sedimentation was omitted. The design of a similar upgrading scheme for a plant at Bundaberg prompted an examination of the performance of the Gatton system, both with and without intermediate sedimentation, during October and November 1981. GA TION TREATMENT PLANT

The Gatton treatment plant has a design population of 6800 and provides screening, primary sedimentation, two stage biological filtratio·n, lagooning and chlorination. Sludge is anaerobically digested and air dried. Sewage is pumped to the plant. Primary effluent gravitates to a distribution structure and is pumped to the primary filter at a constant rate of 50 Lis. The filter distribution system comprises a series of fixed nozzles. Effluent from the.primary filter gravitates to a second chamber in the distribution structure and hence to the secondary filter's rotary distributor. The primary filter feed pump is controlled by suction water level and operates intermittently. While the feed pump is not operating, primary filter effluent is recirculated through the primary filter at a rate of 10 Li s by a separate recirculation pump. Standby units are provided for both feed and recirculation pumps. · The opportunity to include intermediate sedimentation between the two filt ers for comparative 'test purposes was offered by the existence of two old primary sedimentation tanks which had not been used since the plant was upf aded in 1976. One of the two recirculation pumps was used to trans r primary filter effluent via temporary pipework to the inlet structu e feeding the two sedimentation tanks. Settled effluent then gtavitated to the secohdary filter . The primary filter effluent pump was controlled by suction water level and discharged an average of 32 Lis in this mode of operation . A volume 'of 6.6 m3 was available in the suction chamber for balancing the 50 Li s inflow. Excess pumping cycle volume cou ld overflow from the slfction chamber and gravitate direct to the secondary filter, by passing the intermediate sedimentation tanks. It is est imated that less than-10 per ceni of the flow during the test period actuall y overflowed

Ken Hartley is a Principal Engineer with Consulting Engineers Gutteridge Haskins and Davey Ply Ltd in Brisbane. 18

and this has been ignored in the analysis of the results . lt was observed during the tests that the rotary distributor on the secondary filter rotated more slowly when the flow rate was· 32 Li s, compared with the usual 50 Li s, but whether this had any effect on filter performance is unknown . The primary filter is 4.8 m square with 4.2 m of LC.I. 'Flocor' plastic media having a specific surface area of 92 m'm 3 • The secondary filter is 24.4 m diameter and 1.75 m deep with a rock media estimated to be 35-75 mm size with a specific surface area of 50 m'lm 3 • The two intermediate sedimentation tanks are 6.0 m diameter with hopper bottoms and the secondary tank is 13 m diameter with a mechanical scraper. TEST METHOD

The test procedure was as follows: I . It was ensured that the plant operated routinely without intermediate sedimentation for two weeks (41 10181-181 10181) . 2. Sampling was conducted for one week to determine performance without intermediate sedimentation (5 day, 191 10181-231 10/ 81) . 3. The plant was modified and intermediate sedimentation put into operation during the following week (261 10181 -30110181) . 4. The plant was run in this mode for another two weeks to allow it to settle down (till 151 11 18 I). 5. During the following week sampling was conducted for a' further five days to determine performance with intermediate sedimentation (161 11 181-201 11/8'1). Samples were collected from the following locations: A. Primary filter feed chamber. B. Primary filter effluent chamber . C . Composite of equal volumes of effluent from each of the two in termediate sedimentation tanks (second sampling week only). D. Secondary filter effluent chamber (unsettled) . E . Secondary sedimentation tank effluent. Four hour samplings (0800-1200 hours) were conducted on all days except Tuesday 2011018 1 when a 24 hour sampli ng was carried out. Hourly grab samples .were composited 4 hourly in proportion to the hourly plant flows. All samples were collei!ted while the filter feed pump was operating; sampling was carried out during the pumping cycle closest to the nominal sampling time. Samples were collected by one man in the alphabetical order listed above, starting when the filter feed pump had been running for 3 minutes . Analyses were conducted in accordance with Standard Methods (APHA et al, 1976) . BOD and SS analyses were done in triplicate, the BOD analyses at three different dilutions, and the results averaged. Flow readings were taken from the magnetic flow meter on the plant influent. The weather was fine during both sampling weeks except for the last two days .. Rain started during the afternoon of Thursday 191 11 181 and con tinued on the following day. This was reflected in the flows for those two days . Wastewater temperature was not measured but is estimated to have been about 24°C. During the test period a local vegetable processing firm was discharging wastewater (particularly potato waste) to the sewer. The company ·later indicated that to their knowledge, waste discharges during both sampling weeks were comparable , Another influence was the return of digester supernatant to the plant inlet. During the two sampling weeks supernatant was returned as usual from one or both secondary digesters from about 0945 to 1100 hours each day except Monday I 61 11 181 . Both quantity and quality were variable but no measurements were made. RESULTS

Figure I depicts the overall behaviour of the filter system based on

SEPTEMBER 1982

WATER

the 4 hour samples (Ind suggests that the addition of intermediate the primary filter solids was comparable. Removal o.lSS was relatively insensitive to overflow rates up to 2 m/ h and averaged 520Jo in the sedimentation did not produce any improvement in performance. It is ' evident that the BOD loading was higher and more variable during the . second week . The calculated filter rate coefficients are set out in Table I and first week and that the final effluent quality responded in a consistent equation (2) is plotted in Fig. 3. manner to variations in influent BOD and flow. · The primary filter effluent BOD for 20/ 10/ 81 was inexplicably high , particularly as the BOD of the secondary filter effluent was comFILTER PERFORMANCE parable with that on other days. As can be seen in Table I, this has the Filter performance has been evaluated using the following model effect of producing a very low rate coefficient for the primary filter (Eckenfelder, 1979): · and a very high coefficient for the secondary filter. The results for that § = e - KA,mDS.p/ q" (I) date have been ignored in calculating the weekly means.

where S So

effluent BOD,, mg/ L feed BOD,, mg/ L K rate coefficient A, = specific surface area of media, m'l m3 D filter media depth, m q hydraulic loading rate, L/ s.m' m coefficient, with reported values ranging from 0.6 to I n coefficient, ranging from--0 .5"ttH · p = coefficient, ranging from + 0.5 to - I e = naperian log base In the present analysis, total BOD, of the feed has been used for S. , and total carbonaceous BOD, of settled filter effluent for S. This approach lumps into the rate coefficient a number of effects, including removal of both soluble and particulate BOD and the performance of the sedimentation tank, but is considered the simplest and most useful. The data have been analysed using various values of m, n and p and the following form of equation (I) found to give the best correlation of the performances of both primary and secondary filters: § = e - KA,D/ qo• (2)

)(

100 t::.

•

SECOND WEEK

)

e )

24 h RESUtTs6

SEC. TANK

n~~ ,· !:!. ~ -------X)(

;;i!

FIRST WEEK

INT, TANKS

.·

)(

)(-------x........_

ffi

V) V)

The value of the rate coefficient, K, has been calculated for both the primary and the secondary filter for each day, based on the 4 hour results. 350

300

200 X

100

~::::::-! •

19/ 10

Figure 1.

21/10

l'l./ 10

Figure 2.

' 500

f!NAL SETTL[OEFFLUEIU

~---)<

23/10

J--x----~-----r.,;;"

------·

•

•oo-~ ~

300

"' >

o---1Lo 200

o- - ~

1.6

2.0

Sedimentation tank perforriian~e.

Date

Primary Filter

Seeondary Filter

19/ 10 (20/ 10) 21 / 10 22/ 10 23/ 10

0.00443 (0.00081) 0.00322 0.00266 0.00208

0.00269 (Q.00550) 0.00287 0.00303 0.00359

16/ 11 17/ 11 18/ 11 19/ 1I · 20/ 11

Mea~'

O.OOllO

0.00305

" Mean·.

Date

Primary Filter

Secondary Filter

0.00285 0.00258 0.00264 0.002-16 0.00242

Q.00261 0.00350 C>.00192 0.00296 0.00163

0.00253

0.00252 .

Means exclude ,coeffidents fo r 20/ 10

100

~ 16/11

..,, _.-d:::-c~,...,::::::::: !;::::::,;11111

' 18/ 11

19/11

20/11

Overall behavjour of the filter system.

The average SS removal in the intermediate sedimen\atjon tanks during the second week has been used to calculate the BOD of settled primary filter effluent during the. first week. In both weeks, settled BOD has been used in the calculations for primary filter effluent and secondary filter feed. The rationale behind this fpr the first week is that settleable solids discharged from the primary filter largely comprise biomass which would not impose a direct BOD loading on the biomass in the secondary filter, and that these solid~ constit1.1.te part of the BOD removed by the primary filter. In adqition, it wiil be seen that analysis of the results in this fashion gives equal rate coefficients for primary and secondary filters during both weeks; if unsettled primary filter effluent were used in the analyses for tl}e first week, the rate coefficients for the primary and secondary filters would be lower and higher respectively during that week while overall performance of the filter system would still be the same as that during the second week. The performance of the sec;!imentation tanks is shown in Fig . 2. It is apparent that the settleability of the secoqdary filter solids was similar in both weeks and it seems reasoniible to infer that the settleability of WATER

1. 2

TABLE 1. FILTER RA TE COEFFICIENTS

~·~ '°°s •,

20/10

FEED

• !I

~ ~

•0

0.8

OVERFLOW RATE (m/h)

WITH INTE"4EOIATE SEOIHENTAT ION

~ x--:-:.__~-

ISO

WITHOIJTINTERHEOIATE SEOIHENTAT ION

•

::; 2S.0

! ~

•

0.4

Application of Student's t test to the weekly groups of results indicates that· there is no significant difference between the mean K values for the primary filter for the two weeks, for the secondary filter for the two weeks or for the primary and secondar filters for each w~ek (.P < 0.10). This means that during the two weeks the primary filter performed consistently and the secondary ·filter ,performed the same whether or not intermediate sedimentation was included. A normal probability plot of the daily K values ·is 'shown in Fig. 4, overall mean K value is 0.0027, with 950Jo confidence limits of 0,0018 and 0.0037. · · ' NITRIFICATION

Nitrification w,as greater during th~ second week when intermediate · sedimentation was in operation. Percentage nitrification is plotted against ·BOD loading in Fig. 5 and compared with risults published by the US EPA (1975). Nitrification efficiency is comparable with the EPA information .when correlated with the BOD loading on the total two filter system but not wheri correlated with the loading on the secondary filter alone (calculated from unsettled feed in the first week) . It is possible that the poorer nitrification during the first week was a result of the higher BOD loading rather than omission of intermediate sedimentation, but this is uncertain.

SEPTEMBER 1982

VALUE S FOR 20/ 10 OM I TTEO

0.9

PRIMARY ·

SECONDARY

FI RST WEE K

0 .8 0. 7

PRIMARY

SECONDARY

SECOND WEE K

VALUE S FOR 20/ 10 OMITTED

0.6 A 0.5

•

o•

•

0.4

PROOAB ILI TY EQUAL TO OR LE SS THAN (%)

Figure 4.

Normal probability plot of the filter rate coefficient.

••

1;15)

0. 3

K = 0.0027

0 V)

---

t 0. 2 ~ -- ~ - -~ -- ~ --0-~ - -~ -0 100 200 300 400 500

~ 600

AD / q0 . 5 V

Figure 3.

Correlation of the filter variables.

SLUDGE PRODUCTION

The total mass of solids removed in both intermediate and secondary sedimentation tanks was 2.5 times greater when intermediate sedimentation was provided, as shown in Table 2. Application of Student's t test indicates that the difference in mean sludge production is highly significant (P > 0.001). The results suggest that, unless there was an unobserved periodic unloading of the secondary .filter when intermediate sedimentation was not provided, solids in the primary filter effluent degraded considerably in the secondary filter. The figures are in general agreement with values given by Pike (1978) . He reports sludge production values of 0.6-1 .1. kgSS/kgBOD, removed from high rate filters and 0.08-0.6 for conventional filters . TABLE 2.

SLUDGE PRODUCTION

Without intermediate sedimentation

With intermediate sedimentation

Sludge production KgSS/ kg BOD, removed

Date

Sludge production kgSS/ kg BOD, removed

22/ 10 23/ 10

0.143 .0.191 0.449 0. 194 0.303

16/ 11 17/11 18/ 11 19/ 11 20/ 11

0.601 0.568 0.425 0.650 1.000

Mean

0.256

Mean

0.649

Date 19/ 10 20/ 10 ·21 110

UTILITY OF FILTER MODEL

The utility of the filter model is illustrated in Fig. 6, where the measured values of effluent carbonaceous BOD, are compared with the 95% confidence limits calculated using equation(2). The fit is considered close enough for design purposes. PONDING

TWENTY FOUR HOUR SAMPLING

Twenty four hour sampling was conducted on 20/ 10/ 81. Unfortunately the 4 hour results (0800-1200) indicate that 20/ 10/ 81 was the most unrepresentative day of the whole two week sampling period. Both the feed BOD and the filtered and total BOD of the primary filter effluent were abnormally high. Nevertheless the 24 hour results do allow the following observations:

I . The final effluent BOD remained remarkedly constant over the day despite the variations in flow and feed BOD. 2. The high value of primary filter effluent BOD in the 4 hour result (0800-1200) also stands out in the 24 hour figures. The BOD falls to a more consistent value in the other 4 hour periods of the day. 3. In every daily 4 hour sampling over the two week period the secondary filter effluent (unsettled) had a lower suspended solids concentration than the influent to that filter. On 20/ 10/ 81 the relative magnitudes were reversed for the other 20 hours. In addition, the SS concentration in the effluents from both the primary and secondary filters rose sharply during the early hours of the morning when feed was applied to the filters less frequent ly. This suggests that the low sludge production without intermediate sedimentation calcu lated from the 4 hour results could be too low because of so lids shedding during other parts of the day. However, the 4 hour and 24 hour sludge production figures for 20/ 10/ 81 are 0.191 and 0.220 kgSS/ kg BOD, removed, respectively , a difference of only 15% . This is much less than the day to day variation in sludge production. 4. The K values for the primary and secondary filters calculated on the basis of: • mean flow rate for the day • flow weighted mean BOD values, anci • 52% settlement of suspended solids from the primary filter effluent at an average 0.53 mg BOD,/ m SS, are 0.0020 and 0.0026 respeciively . These are much closer to the mean 4 hour value for the two weeks (0.0027) than are the 4 hour values for the same day given in Table I (0.00081 and 0.00550 respectively) . 5. Secondary sedimentation tank performance for the six 4 hour periods over the day was consistent with the 4 hour performance on the other days (Fig. 2) .

Ponding of a secondary filter occurred in English experiments when an intermediate sedimentation tank performed poorly (Hambleton and Kirby , 1974). However, the Gatton plant has operated satisfactorily without ponding for 5 years since the primary filter was commissioned. The difference in hydraulic loading rates may offer an explanation . The English filter was loaded hydraulically at about 0.014 L/s.m', whereas the secondary fi lter loading rate at Gatton during the test period averaged 0.050 L/ s.m' and the influent was actually applied to the filter at 0.1 I L/s .m' (50 Li s) .

SEPTEMBER 1982

WATER

\<\ ""''

300

OF EPA OATA \ '°" FILTERS, 2<» C.

N >u

u.J

• • \ \

• • 6

FIRST WEEK

SECOND WEE K

..s Cl 0

100

----~"

------~

-:::::.--z;---: 6

6 ~

Nitrification efficiency.

FIRST WEEK

It is concluded that : I. The removal of carbonaceous BOD by the two stage filter system at Gatton was the same whether or not intermediate sedimentation was provided . 2. Nitrification was greater during the week that intermediate sedimentation was provided; it is possible that this was a result of the lower BOD loading during that week. 3. Total humus sludge production was 2.5 times greater when in termediate sedimentation was provided . 4. No ponding had been experienced over the 5 years of operation without intermediate sedimentation. It is possible that this cou ld have occurred at lower hydraulic loading rates. 5. Equat ion (2) provides a reasonable description of the performances of both the plastic media primary filter and the rock media secondary filter.

Figure

ACKNOWLEDGEMENTS

This investigation was conducted for the Bundaberg City Council with the encouragement of the Queensland Water Resources Commission. Plant operation and sampling were carried out by the Gatton Shire Council and laboratory analyses by Toowoomba City Council. T he three Councils have kindly given permission for this paper to be published .

AWWA MEMBERSHIP Notice to Applicants Application forms are available from Branch Secretaries (addresses on page 7 this issue) and sllould be completed and returned to the appropriate secretary. Fees are plus state levies where applicable.

CONCLUSIONS

WATER

I \ \/ 0

B0D 5 LOADING (lb/1000 ft~d)

Figure 5.

"" \

• --' 150 ...... O>

/o-O~EO

200

TOTAL FILTER SYSTEM

.,. "' "' "' "' "' "' 6

SEC. FILTER

SECON D WEEK

FIRST WEEK

• \ •

VOL. LOADI NG

:x>-

•

~ u. u.

t:,.

250

SETTLED PRIMARY FILTER EFFLUENT SETTLED SECONDARY FILTER EFFLUENT

SECOND WEE K

Comparison of measured tank performance calculated 95 per cent confidence levels .

with

REFERENCES APHA, A WW A and WPCF ( I 976) 'Standard Methods for the

Examination of Water and Wastewater' , 14th Ed. (Amer. Public Health Assoc.) . EKENFELDER, W . W. (1979) 'Princip~ls of Water Quality Management' (CBI Publishing Co ., Boston) . HAMBLETON, F. E. and KIRBY, T . H . (1974), Pilot plant investigations into partial pretreatment systems at Macclesfield, Wat . Pollut. Control, 78, 522. US EPA (1975) 'Process Design Manual for Nitrogen Control'. WPCF and ASCE (1977) 'Wastewater Treatment Plant Design , Manual of Practice No 8' (WPCF). PIKE, E. B. (1978) 'The Design of Percolating Filters and Rotary Biological Contactors, Including Details of International Practice', Tech. Rep . TR 93 (Wat. Res . Centre).

Membership is in four categories : • Member- qualifications suitable for membership of the Institution of Engineers (Aust .) or equivalent qualifications of similar professional organisations. Fees $20 p.a. • Associate -Exper ience in the water and/or wastewater industry without formal quali fications. Fees $20 p.a. • Student . Fees $5 p.a. • Sustaining Member-an organisation or firm involved in the water and wastewater industry , wishing to support and further the aims of the Association. Fees $100 p.a.

SEPTEMBER 1982

AUSTRALIAN SOCIETY FOR LIMNOLOGY 21st Conference-·Griffith, N.S.W. The address of the retiring President, to this Conference and a number of the papers presented are thought to be of interest to A. W. W.A. members and precis reports follow. The Society, with a current membership of 425 has, since its inception in 1961, vigorously promoted the role of limnological research and education through the organisation of conferences and various publications. Membership is multi-disciplinary and activities are directed to the management and conservation of aquatic resources and

the Society provides an authoritative and responsible voice on limnological matters and brings local ecological knowledge to a field where overseas research and experience can be inadequate. Full details of the Society and of membership requirements are available from the Secretary, Mrs. M . Hart, Department of Chemistry, Chisholm Inst. of Technology, P.O. Box 197, Caulfield East 3145.

MORE FINANCE FOR WATER RESEARCH The President of the Australian Society of Limnology for 1981 -82 was Mr Frank Burns, the first engineer to have h::id the honour of that position. Frank was the leader of the S.R.W.S.C. team which investigated destratification of reservoirs, and he is now working as a consultant, primarily in reservoir quality control. In his retiring Presidential address at the 21st Conference in Griffith, Frank gave voice to some cogent thoughts on the financing of research . Agreeing fully with the fact that there is much work to be done in Australia researching into the many limnological and water supply peculiarities of our own country, which nobody else is going to do for us, he yet asked the question 'Are water supply engineers ~oing to be able to use the results?' He made the point that whatever the finance for research, most of the money to put the results into action has to come from reve1;1ue, that is, direct from the public-from you and me. He then listed the typical priorities for household expenditure per year: $ Housing (to impress the neighbours) 4000 Food (not including the parties) 3000 Car (we must be mobile) 2000 Electricity (to run the TV) 400 Oil (to keep us warm by the TV) 400 200 Telephone (mainly for teenage daughter) Sewerage (a real essential) I 50 Water (why do they charge so much?) 70 In other words , rather reluctantly, we give the Water Authorities about one quarter of one per cent of our income to maintain storages, pipelines, services, and to employ the technical staff and equipment to implement the latest advances in water research .

Let us suppose, said Mr. Burns, that the Commonwealth could be persuaded to divert more of its tax harvest to water supply. They are not a Water Authority directly involved in supply, so all they could do would be to supply more money for capital works - which the At1thorities cannot afford to operate and maintain - or for more research - which the Au\horities cannot afford to implement. In their great era of development, the Water Authorities cou ld truly be proud of their achievements. In this, the driest continent, they supplied the highest per capita consumption in the world. They led the world in water legislation and stream gauging; construction of dams, channels and pipelines was second to none. However, that era is now past, and the emphasis must be more on management of the works which have already been built. There is more awareness and concern for our environmental responsibilities, and a demand for reservoirs which people can enjoy, and water which can be drunk without wrinkling the nose. · Water research is providing the knowledge and the technology to meet these new demands, but, asked Mr. Burns , who is providing the money to implement them? Capital works come from loans (usually subsidised), operation and maintenance must be funded from revenue . This means increased water rates, a politically sensitive issue because of the attitl.½le that you and I take as ratepayers. Unless we realise our obligations and demand (acquiesce?) realistic pricing of our water services, we are in the ludicrous position of having the technology to obtain good quality water but being un'.,,,,illing to pay for it. Only when Water Authorities are in a position to implement new ideas, will there follow an increased demand, or market, for further research . •

LIMNOLOGICAL CONSEQUENCES OF INDUSTRIAL AND URBAN DEVELOPMENT D. W. Connell, Griffith University, Brisbane

mineral processing has been taking place for some time without extensively devastating any biological systems. The natural resilience of ecosystems has long been overlooked, and the concepts of contamination and pollution, which is the excess contamination over the capacity of the ecosystem to absorb it l!re discussed. The environmental impact of some of the more dangerous contaminants from Australian mining is discussed. The role of the freshwater biologist in determining and reducing the environmental impact of mining operations is also discussed.

.. . .

In the last 10 to 15 years, the objectives of water managment in Australia have undergone considerable change. Today, in addition to traditional uses, water quality management aims to provide suitable water for recreation and to conserve aquatic life. This presents a more difficult problem since standards in recreation and conservation are difficult to define. There is a dependence by water management authorities in Australia on water quality standards and data developed in Europe and North America. In some parts of Australia, differences in ambient water temperatures and seasonal patterns of rainfall indicate that they may be inappropriate. The managment of water is substantially in the hands of State and Local government bodies. However there is an urgent need for co-ordination and co-operation at a national level to achieve adequate level of research into peculiarly Australian requirements in water management. A National Water Research Institute is needed, guided by a national consultative body. A funding scheme based on water users, akin in principle to research levies on wheat and wool, should be developed. THE IMPACT OF MINING ON FRESHWATER ECOSYSTEMS T. P. Farrell, CRA Limited, Melbourne

Mining can have a considerable environmental impact when emissions into freshwater ecosystems are considered. However mining and

SALINITY TRENDS IN LAKE MOONDARRA A. Mccredie, Mount Isa Mines Ltd.

Lake Moondara, a water supply impoundment, has increased in T.D .S. from a historical level of about 200 mg/ L to a current level of 300 mg/L, ranging up to 400 mg/ L during dry low lake level periods. The dam's spillway was raised by 1.52 min 1973, and this has been primarily responsible for the change in the T.D.S. , although it was not initially evident due to a series of exceptionally wet years during which the lake regularly overflowed. The raised spillway increased the maximum volume held from 79 to 107 million m3, and the maximum surface area of the lake from I 7 .2 km 2 to 23 .8 km 2 • The Lake Moondarra situation is being examined to determine whether the salinity has stabilised at the current acceptable level. If T.D.S. continue to rise, it may be necessary to lower the spillway, or implement land use controls.

SEPTEMBER 1982

WATER

PHANTON MIDGES (CHAOBURUS) IN MYPONGA RESERVOIR P. J. Suter, State Water Laboratories, E.&W.S. Dept., S.A.

The air curtain installed in Myponga Reservoir did not function to keep Chaoborus larvae away form the outlet tower, but by lowering the depth of the thermocline it actually displaced the high concentrations of phantom midge larvae away from the offtake valves. Therefore, the air curtain had the desired effect; of reducing the number of phantom midges entering the distribution system. WATER QUALITY CONTROL IN LITTLE BASS RESERVOIR F. L. Burns, Consulting Engineer, Glen Waverley, Victoria

Little Bass Reservoir, of 240 ML capacity and a IO m maximum depth, services three towns in Gippsland, Victoria. In the 1980/ 81 summer, algal problems and anoxic water due to thermal stratification made the water completely undrinkable. Emergency aeration with a 100 CFM compressor gave some relief from these problems late in the summer. In the I 981/82 summer the reservoir was kept destratified by intermittant operation of a 25 CFM compressor, at a cost of about $5 per week. This kept the water in excellent condit ion. The success appears to be associated with the production of an active benthic population carrying out a waste stabilisation role. This throws doubts on the wisdom of using copper su lph ate to reduce algae . AN INTEGRATED AQUACULTURE SYSTEM FOR THE TREATMENT OF WASTEWATER P. M. Nuttall, Dandenong Valley Authority, Victoria

A field-trial aquaculture system for the purification of stabilization pond effluent is described. The initial aim of the system was to achieve significant and continuous macronutrient and phytoplankton removal from secondary treated sewage effluent discharged to a watercourse. Over a period of one year, only on two occasions was high nitrification achieved. Uptak~ of macronutrients occurred but a maximum removal of 2.5 mg/ L total phosphorus has been achieved. Phytoplankton removal as ch lorophyll-A was good. Alth ough harvesting of plants is necessary to remove assimi lated nutrients, a reduction in the plant cover affected both the incidence of phytoplankton, and the availab le immersed substrate for microbial attachment important in nitrification processes. It is unlikely that denitrification contributed to overall ammonia-nitrogen removal. The composition of macroinvertebrates in the system is similar to those in stabi li zation ponds. Invertebrates are recognised as an important nutrient sink and as a concentrator of contaminants. Removal is through the mergence of adult aquatic insects, and trophic levels to fish. Survival and growth of some fish and crayfish species in the system are being monitored. TREATMENT OF WASTEWATER USING AQUATIC MACROPHYTES M. Finlayson, CSIRO, Griffith

The potential of three emergent aquat ic plant species to treat effluent from a poultry abattoir was eva luated in a short-term experiment involving percolation through plastic lined gravel trenches. The system successfu lly reduced the suspended solid s, turbidity, nitrogen and phosphorus concentration in the effluent while maintaining an acceptable pH and with some species oxygenerating the anaerobic inflow. These results are used as a basis for future work . ST A TUS OF CARP IN VICTORIA D ; J. Hume and A. R. Fletcher, Fisheries and Wildlife Division, Shepparton, Victoria

Carp were introduced prior to 1908. In 1961-62 a new strain was introduced and eventually spread throughout sout h-eastern Australia. Numbers of carp apparently have declined since the early 1970s. Research conducted by the Carp Program, since 1979, has been aimed at determining the distribution, abundance, and life history patterns of carp as well as determining the effects of carp on the aquatic environment. Fish communities containing carp were considered with respect to competition and predation interactions. The main food items of carp were invertebrates. These consisted of microcrustaceans and aquatic and larval insects, from midwater or benthal areas . Plant

WATER

matter was only eaten in minor proportions by a fel!i large carp . The evidence for carp being responsible for physical destruction of aquatic habitats is considered . Carp seemed to rarely uproot or directly consume macrophytes. Some physical disturbances may occur when large numbers of carp are present, as indicated by a comparison of vegetation between billabongs. A comparison of turbidity values from all permanent sites and in experimental ponds did not support the contention that carp disturb bottom sediments and increase turbidity. INVERTEBRATES OF THE RIVER DEE IN RELATION TO THE POSSIBLE EFFECTS OF COPPER MINING A. P. Mackey, Capricornia Institute of Advanced Education, Rockhampton

The Dee is an intermittently flowing river that has been subject to the effluent from a copper mine. To observe the effects that copper mining may have had on the macroinvertebrates in the river, a longitudinal fauna! survey was conducted. The n umber of invertebrate taxa was depleted downstream of the effluent and this was associated with marked changes in the copper concentration in the water, and water pH. Twenty-two kilometres downstream of the effluent, the invertebrate fauna had begun to recover but even 46 km downstream of the effluent, the fauna had still not fully recovered. This was best demonstrated by the absence of molluscs. Further work may make it possible to identify indicator groups useful in the biological monitoring of mine effluents. LAKE MOONDARRA-CHANGES FOLLOWING BIOLOGICAL CONTROL OF SALVINIA T. Orr, James Cook Unversity, Townsville

Changes in the hydrobiology of Lake Moondarra have been monitored subsequent to the introduction of Crytobagous singularis to control the aquatic weed Salvinia moles/a. Special attention has been directed towards macro nutrients in the lake waters and their effects on plant biota, especially phytoplankton. No evidence of a major buildup of N and P was noted during decomposition of the Salvinia mat, and significant algal blooms did not occur. There was, however , a rapid increase in the standing crop of the rooted macrophyte Myriophyllum verrucosum. HYDROLOGY AND NUTRIENT LOADING IN LAKE JOONDALUP ' R. A. Congdon, Monash University, Victoria

The water and nutrient budgets of Lake Joondalup (near Perth) were investigated over 27 months to pro~_ide guide-lines for the management of the lake. As a consequence of the mediterranean climate, the lake experiences large seasonal fluctuations in volume. Swamps to the south of the lake accounted for 88 per cent of the surface discharge into the lake during 1980, with the remaining 12 per cent coming from stormwater. There is no surface flow from the lake, and groundwater contributed a net input. The southern swamps supplied some 73 per cent of the external phosphorus loading to the lake, rainfall 26 per cent and stormwater only I per cent. Seventy-eight per cent of this input was lost to the sediment and metaphyton, and uptake by macrophytes. The large phosphorus loading from the swamps stim ulates blooms of the bluegreen alga. Rainfall is the most important nitrogen input, supplying 69 per cent of the external loading. The swamps supply 30 per cent and stormwater about I per cent. A nett loss of nitrogen was recorded from the lake water column .

B~atth~ .... AWWA 10th FEDERAL CONVENTION

Sydney

SEPTEMBER 1982

11th-15th April 23

BOOK REVIEWS Rivers of Energy: the Hydropower Potential. D. Deudney. Worldwatch Inst. Washington D.C. US$2 . This monogragh of 55 pages assesses the present and future use of hydropower on a world basis. In I 980, 23 per cent of the world's electricity was derived from this source, the combined capacity being 363 000 MW. It has been estimated by the World Energy Conference that even with all the environmental and economic restraints, this could be multiplied four to six times. Contrasted to the state of development in Europe, 59 per cent of potential; North America, 36 per cent. Asia and Africa have only developed 9 and 5 per cent respectively. The monograph discusses such disadvantages as ecological damage, health effects, silting, salination of irrigation areas downstream and disturbances of fish production. The subjects of conflicts over water ;ights versus states of mutal dependence and forecasts for the aluminium industries are also touched upon. The booklet is a well reasoned exposition of the pros and cons of hydropower .

The authors, Robert Dean who has directed a large number of projects in the A WT Programme of the USEP A and Ebba Lund, Professor of Virology in Copenhagen, have extensive experience in this field. They consider that reused water can be safe for all municipal uses provided it is prepared by appropriate technology and that safeguards against system failure are built in from the start. This limits application to large communities. The book is written for people who, either as public managers or informed citizens wish to learn more about the problems and possibilities of water supply augmentation without necessarily having advanced scientific or engineering training . The authors have covered every issue in this field in a straightforward and honest manner with the minimum of jargon . The book is highly recommended for general readers and tertiary educational institutions.

encouraging to see articles a{ this standard in 'Water' . I congratulate the authors and also the editorial committee. STEPHEN HANCOCK Australian Groudwater Consultants P / L

* * * •

DILUTING EQUIPMENT 'BRAND' The manual Diluette is ideal for laboratories carrying out a limited number of dilutions and provides an efficient and economical alternative to pipetting. The four sizes range from 20-500 u L for the sample and 0.1-0.5 m L for the reagent.

E. A. SWINTON * • * •

TO THE EDITOR

E. A . SWINTON

Ozone Treatment of Industrial Wastewater. R. G . Rice and M . E. Browning: Noyes Data Corporation, Park Ridge, New Jersey, U .S.A .. This book, No . 84 in the Pollution Technology Review series, is based primarily on information in a literature survey entitled "Ozone for Industrial Water and Wastewater Treatment" (E.P .A . 600/2-80-060) also prepared by the above authors . A useful introductory section on oxidation processes compares the relative mertis and fields of application of biological, air, thermal and chemical oxidation. This is followed by a section on the fundamentals of ozone technology. The main body of the book is a survey of industries grouped into 20 categories and discussed in alphabetical order . A survey of the literature dealing with the oxidation products of ozonation follows. The final chapter covers the rapidly growing field of Biological Activated Carbon. The book is well illustrated with clear graphs and line drawings and a well selected bibliography concludes each section. The authors have combined in one volume a considerable body of information which will be invaluable to ~orkers in this field.

R. McNEILL Water Reuse: Problems and Solutions. Robert B. Dean and Ebba Lund. Academic Press. London. $38 .00. This small but valuable book of 250 pages reviews the problems of municipal water supplies which may contain varying fractions of reused water , either intended or covert. There is special emphasis on the pollutants which seem to pose the greatest risk. It presents the treatment processes available and discusses both their capabilities and limitations.

Sir , In reference to the paper by Smith and Schrale in the March 1982 Journal, I should like to congratulate them on an excellent summary, but I feel that it is perhaps premature to assume that there are no rapid movement paths. In the analysis presented, porosity is assumed and is said to be confirmed by the movement rate measured, the actual pollutant load however is not in balance. Their contention that fixation of pollutants near the disposal site may be valid , but it is also possible that if the porosity is lower than they believe a significant volume may be moving undetected down preferred flow paths at a rate markedly faster than that in the mass. Such a phenomenon represents a real short term danger to the Mt. Gambier water supply . These would not necessarily be seen by vertical electrical sounding. It would seem to us that electrical resistivity traversing at a carefully selected current electrode spacing should be carried out and used as a basis for siting further holes. Without this the results must be questionable . In addition neutron and density logging of the existing and new holes to evaluate porosity is desirable. Finally, since nitrate is a very persistent waste in the groundwater environment a more rigorous approach to denitrification may be necessary than just dilution and irrigation. Controlled intermittent infiltration has achieved better than 60 per cent NO 3 removal consistently. It could have real application here if the problem is of sufficient real magnitude long term. Finally containment of the plume by transfer of water from upstream to downstream could also be practised. Consideration of these matters in relation to the problem should provide readers with a good insight as to water problems of which they do not commonly confront. It is most

SEPTEMBER 1982

For frequent diluting the MUL TILUTOR (illustrated) covers a working range of 20-1000 uL of sample and 0.2-20 mL of reagent by eight modules. The equipment provides steplessly variable volume and dilution ratios while the metering rate can b'e matched to both volume range and the working medium . Further information: Townson & Mercer, P.O. Box-.501, Concord, N.S.W. 2137.

HYGROMETER FOR TRACE MOISTURE MEASUREMENTS The New Model 300 EG & G chilled mirror hygrometer continuously accounts for contamination build-up as well as automatically adjusting critical loop constants. This is a primary measuring instrument with nominal accuracy of ± 0.2°c with dew point range of - 100°F to + 212°F which by means of a microprocessor carries out continuous optimal balancing to compensate for the effects of sample contaminants. The microprocessor also continuously ad justs all critical control loop constants. Sample pressures from vacuum to 300 psi can be used. Standard features include sensor diagnostics, large 0.8 in LED display, control condition logic signals, test voltmeter and keyboard array of function/status switches. Numer-ous options are available. Information from: Leeds & Northrup Aust. P/L, 18 Mandible St., Alexandria 2015.

WATER

NEW TEMPERATURE TRANSMITTER KENT INSTRUMENTS

LOW COST AUTOMATIC FILTER

Kent have produced an updated version of the successful Kent K-tran V temperature/e.m.f. Converter- the new Model V-VB. With new circuitry and recently available components the new Model V-VB is technically superior to the original version and less expensive. The K-tran V Converter accepts d.c. voltage , current and resistance inputs from sources such as thermocouples , resistance thermometers , process transmitters, gas analysers etc. , isolates and amplifies them and generates an accurate and proportional 4 to 20mA, 0 to 10mA or Oto 10V d.c. output signal. Two mounting forms are available , one suitable for surface mounting (with a sheet metal cover as illustrated) and the other suitable for mounting by itself or with a second Converter in a standard IP65 hoseproof case. Th e RF screen fitted to this second mounting form also makes it suitable for installation in equipment enclosures , cubicles etc . where the protective cover of the standard surface mounting case is not required . For information: Douglas J. Rickard, Marketing Manager, 70 Box Rd ., Caringbah 2229.

The FIL TOMAJ" is an in-line steel unit in size range 2 to 14 inches, powered completely by the internal line pressure and automatically removing the accumulation of solids via rotating suction fins.

FIL TOMA TS are applicable to a variet y of industrial and agricultural purposes for the removal of algae, sand and sediment , for the clarification of water, the protection of drip , spray and sprinkler systems, cooling towers and heat exchangers and in wastewater and water purification plants . Further information: Triangle Industrial Products, 95 Ormond Rd. , Elwood, Vic. 3184.

SODIUM FLUORIDE SATURATOR FOR SMALL WATER SUPPLIES The ADVANCE 11 Series FS100 sodium fluoride saturator, a system designed for adding fluoride to drinking water, is now available from Acromet (Aust.) Pty. Ltd., a major manufacturer/distributor of chlorination equipment and related products. It is the most complete saturator system in the industry for use with small water supplies, especially those below 3,800,000 litres per day. The unit is a pump and tank assembly with a swirl -action diffuser, that mi xes water up through a dr. sodium fluoride bed placed in the bottom of the tank. The resulting fluoride solution is then fed by a metering pump into the water supply. The saturater comes completely assembled from the factory in floor or wall mounted versions. Both models are easy-to-install , requiring few on-site con nection s. Many outstanding features are includ ed as standard with this system. An inlet flow restrictor provides an optimum water flow of 15 Umin through the fluoride bed. Two separate anti -siphon valves prevent fluoride from siphoning back into the water supply and the uncontrolled flow of solution in case of negative pressure at the injection point . For information: Acromet (Aust.) P/L, P.O. Box 491, Clayton, Vic. 3168.

TOTAL CAPABILITY IN

CONTROL

In Mechanical, Process and Biological Engineering Mechanical Engineering Grit remova l pl ant Screening press and bagger un it Circu lar and rectangu lar sedimenta tio n tan k sc rapers Slu dge conso lidatio n tank thi cke ners. m ixing ta nk sti rre rs Sludge dryi ng bed mec hanica l lifters Sa nd bed lifters Contra Shear rotary scree ns

~ HAWKER

Process Engineering The rma l and c hem ical sludge conditio ning pl ants TC In cinerator for scree nings Mu ltiple hearth . fluidised bed . rot ary drum slu dge inci ne rators Static gra te inci nerator Disso lved ai r fl otatio n Ca rb on regeneration and absorptio n systems

Biological Engineering Standard ised activate d sludge pl ant for sma ll populat ions o f up to 20 .000 pe rsons Extended aerati on plan t. Aerob ic sludge digest ion . Diffused air activated sludge pla nt Automatic contro l systems fo r act ivated slu dge plant

SIDDELEY ENGINEERING PTV. LIMITED Incorporated in NSW

Head Offi ce : 262-2 84 He,de lberg Rd . Fa or t,etd . v ,c 30 78 Te l 489 25 11 Branch es : Sydney • B ris ba ne • Pe rth• Auck land Hawke r S1dd eley Gro u p su pp lies ele ctr ic al and me ch an ic al eq u ipment w ith wo rld- w ide sa les ano serv ,ce Agen ts l or Ha wke r S1dd ete y W ate r En g ineer ing lt d ( Tem plew ood Hawks ley A c t 1vat ~d Slud g e ) 3~60H$E

WATER

SEPTEMBER 1982

You can depend on most chlorine residual analyzers not to work.

TORRENS INDUSTRIES Tl 1003 GENERAL ALARM MONITOR AND PAGING SYSTEM

FIELD PROVEN The Tl 1003 is a field-proven alarm monitoring and alerting system which amongst other applications is particularly suited lor monitoring waste water pump stations. MICROPROCESSOR BASED The system is microprocessor based and wi ll report and log alarms from up to 64 pump stations with 8 inputs each. UHF RADIO PAGER Unattended alerting is via self-conlained UHF Radio Transmitter and pockel pagers which have a lypical ra nge of 30 ki lometres .

Or you can rely on one that does.

SYNTHESISED VOICE When an alarm occurs and the system is in lhe " remote" mode , lhe microprocessor " speaks " the synthesised station an d alarm inlormation via the pocket pager units and also by phone , whe n the operator acknowledges receipl ol the alarm.

Unfortunately, a typical analyzer spends most of its working life not working. No matter what any manufacturer might claim. But then , Capital Controls is not just any manufacturer. And our ADVANCE Series 870 is no ordinary analyzer. In fact, we consider it the most reliable in the industry. We believe you will, too. The 870 offers some rather unique features such as a positively driven electrode cleaning mechanism that eliminates signal drift and greatly reduces maintenance requirements . For normal service, the 870 needs only a weekly comparison check, no zero or calibration adjustments. With our analyzer, sample and reagents are gravity fed continuously, so metering pumps (often responsible for interrupted operation) are not required. -Better signal strength is achieved by the 870's gold and copper electrodes, which are many times bigger than others on the market. And a special thermistor ensures signal accuracy by automatically compensating for sample temperature variations. Whatever your specific needs, ~ Series 870 has versatility to match reliability. We offer two analyzer models that measure either free or total chlorine residual and monitor in seven ranges (from 0-0,5 mg/I to 0-20 mg/I) . They are available singly, with an indicator or chart recorder, or as part of any size ADVANCE chlorine residual, compound loop, or skid mounted gas feed system. Most companies who make analyzers also make excuses. We prefer to build analyzers that work.

FUTURE EXPANSION An important feature ol the system allows unskilled person nel 10 add future stations by pl ugging a circuit card into the base and adding a Transponder in the remot e station. The microprocessor is pre-programmed 10 accept up to 64 slations . No adjustments ate required . DATA GATHERING PAN EL Allows unskilled operators 10 expand system tram 1 to 64 pump stations by plug -in cards and addi ng remote Transponders . front panel LED 's display all alarm points . the system is lully Telecom approved (No. C79Âˇ26Âˇ41) .

MICROPROCESSOR MODULE Incorporates printer , date and time display, voice syn thesiser, phone acknowledge circ uit . audible alarm sounder and accept key . All station and alarm inlormation is printed together with date and time . PAGER MODULE Includes pager encoder and UHF radio transm itter. Fron t panel keyboard allows manual page tacility lor contacting personnel within a lypical 30 km radius.

Ill

CHARGER AND BATTERY MODULE Separate vented enclosure includes " no maintenance " ba tt ery wh ich ensures 24 hour continued operation in the event ot power lailure . No power is required in th e lield. as all Transponders receive their power from the base of Telecom lines .

Torrens Industries manufactures a full ra nge ol equipmenl including 7000 series V. F. Remote control and indicalions equipmenl. Tl t 000 Fire Reporting Systems and Tl 1010 Portable Evacuation Ala rm Units .

For more information on the Tl 1003 or other product lines, contact:

- . .-/'

Field Transponders

ADVANCE ... at your service.

~:!';2,~'~;;: w;,-m,,"

i;! ROM

ACROMET CAUST.J PTY. LTD.

l~l Torrens Industries E-;J

Telephone : (03) 544 7333 . Telex: AA 30918 N.S.W.: 19 G1bbes St., Chatswood , 2067 . Telephone : (02) 407 0201 Telex : AA 22586 ACR1 3

SEPTEMBER 1982

Orb House, 95 Wollongong Street, Fyshwick A.C.T. 2609. Telex: 62044 P.O. Box 41, Torrens, A.C.T. 2607, Au s tralia Telephone: (062) 80 6609, 80 6897

WATER

Portable, High Performance Unit-Made in Australia This new Nephelometer was designed in conjunct ion w ith CSIRO and is used for the measurement of the turbidity of fluids . It has an extremely wide range and most samples can be measured directly without being diluted . A feature of the instrument is that it can be adapted to measure refract ive index by us ing a separate probe assemb ly wh ich is av~ ilable as an accessory.

D D D D

Three ranges: 0-2000 NTU ; 10-20 000 NTU ; 100-100 000 NTU Compact size for easy field use Digital liquid crystal display Push button operation Probe can be connected directly to control unit or attached using extension lead

SELBYS SCIENTIFIC LTD. Melbourne

Sydney

Brisbane

Perth

Adelaide

Hobart

544 4844

888 7155

371 1566

451 2577

51 4651

28 4691

~ ENVIROSHIELD

â&#x20AC;˘

~ ~

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 1982

• 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 MPa 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 - either centrifugal or the simple and robust Roots type. Major uses include smelter gas exhausting, 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 .

Donkin products, associated with the gas industry for 150 years, are utilised in gas compression and control for process engineering, industrial gas supply and pneum atic conveying in every part of the world.

,._,, Hawker Siddeley Engineering Pty. Limited Incorporated in NSW

Head office : 262 -284 Heidelberg Road, Fairfield Vic. 3078. Tel : 489 2511 Branches : Sydney, Brisbane, Perth. Hawker Siddeley Group supplies electrical and mechanical equipment with world-wide sales and service.

3397 HSE 10

WATER

More sizes. More options. Amillion ways to specify the DeZURIK eccentric valve. 28 sizes, Â˝"-72" . 15 body materials. 5 end styles . 5 packing materials . 9 resil ient plug facings. 5 actuators and 29 accessory options . Over a million combinations , and DeZURIK controls the quality every step of the way. The DeZURIK foundry and rubber molding operations assure material quality and valve performance . Actuato rs are designed and built to valve requirements . Versatility. Quality control. Proven performance . That's why DeZURIK eccentrics are specified for the toughest municipal applications. Eccentric action and resilient plug facings- for a lasting, dead-tight shutoff.

Rugged, machined bearingsprevent binding and assure lasting , easy operation without lubrication . Corrosion resistant nickel seat minimizes plug wear on all 3"-72 " cast iron valves. Multiple ring stem seal- seldom , if ever, requ ires adjustment or

~---

replacement, even under continuous operation . For more information contact: DeZURIK OF AUSTRALIA PTY. LTD. P.O. Box 204, Vineyar Road Sunbury, Victoria 3429 , Australia, Telephone : 03-744-2244 Telex : AA33732

~ ~ -- TOTALLY ENCLOSED POWERED OR MANUAL ACTUATORS

___.,,

WELDED-IN NICKEL SEAT

~ ,/

CORROSION RESISTANT BEARIN GS A U NrT OF GENERAL SIGNAL

DeZURiiK Ad No. 1978-3 Printed in U.S.A. CApril 1978 DeZU