Water Journal December 1980

I 1ssN 0310 - 03671 Official Jgurnal of the AUSTRALIAN WATER AND Vol. 7, No. 4, Dec. 1980 Registered tor posting as a periodical -

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EDITORIAL

Chairman, C. D. Parker F. R. Bishop Mary Drikas E. A. Swinton T. M. Smyth B. S. Sanders Joan Powling T. Fricke W. Nicholson W. E. Padarin J. H. Greer B. J. Murphy P.R. Hughes J. Bales H. Wilson Editor: Publisher: G. R. Goffin A.W.W.A. BRANCH CORRESPONDENTS CANBERRA A.C.T. C. Coucouvinis, Ci- River Murray Commission, P.O. Box 409, Canberra City, 2601

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

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Association News ........ . .. .. .. . .. . ... .. .. . .. . ..... .

6

062-480-177

Retiring President Reports . ... . ... . ... .. .... ... . . , ... . .

10

NEW SOUTH WALES T. M. Smyth, G. H. & D. Pty. Ltd., P.O. Box 219, Neutral Bay Junction, 2089.

02-908-2399

The Philosophy of Australian Water Legislation - Part II - Sandford D. Clark .. .. .. . .. . . . ........... ... ... .

11

Water Quality Management in Arid and Semi-aird Environments - Barry T. Hart . .. . . ... . ..... . . . . . . ..... . ... ... .. .

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Water Resource Allocation by Land Use Control - M. R. Till .. . .. ... . . . .. . . .. .. ... . .. ... . . . . . .. . . .

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Activated Sludge Treatment Subiaco - W. Australia Developing Operating Procedures - Allen J. Gale .. .... . . .. .. . .... . ................ .

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Economic Effluent Treatments and Re-use of Water in the Textile Processing Industry - M. W. Simmons .... . . .. . .. .. . ............. .. . . .

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Calendar .. . ....... . ....... .... ....... . ... ·•· ..... .. . .

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People -

Comment . .. .. .. . .... .. . . . . . . . .. .

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Letters ............ . .... . ... . . . . . .. . .. .. . .. ... . ..... .

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VICTORIA J. Bales, E.P.A., 240 Victoria Parade, East Melbourne, 3002.

03-651-4685 QUEENSLAND P. R. Hughes, P.O. Box 276, lndooroopilly, 4068.

07-378-9111 SOUTH AUSTRALIA Mrs. M. Drikas, State Water Laboratories E. & W. S. Private Mail Bag Salisbury 5108.

08-258-1066

WESTERN AUSTRALIA C. M. Tucak, 18 Ventor Ave., W. Perth 6005 09-321 -2421 TASMANIA

R. Camm, Cl- Met. Water Board, Macquarie St., Hobart.

002-30-2330 NORTHERN TERRITORY H. Wilson, Water Div. Dept. of Transport & Works, P.O. Box 2520, Darwin NT 5794.

089-81-2450

Products -

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VIEWPOINT

!AUSTRALIAN WATER AND! !WASTEWATER ASSOCIATION!

FEDERAL PRESIDENT D. J. Lane, State Water Laboratories , E & W.S. Department, Private Mail Bag, Salisbury, 5108 FEDERAL SECRETARY P. Hughes, Box A232 P.O. Sydney South, 2000.

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

BRANCH SECRETARIES Canberra, A.C.T. D. Coucouvinis, Cl- River Murray Commission, P.O. Box 409, Canberra City, 2601. (480-177) New South Wales R. M. Lehman, Sinclair Knight & Partners, 2 Chandos St., St. Leonards, 2065. (439-2866) Victoria J. Park, S.R.W.S.C., Operator Training Centre, P.O. Box 409, Werribee, 3030. (741 -5844) Queensland J . Ryan, Cl- Gutteridge Haskins and Davey, G.P.O . Box 668K, Brisbane, 4001. (221-7955) 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, Cl- Fowler, England & Newton, 132 Davey St., Hobart, 7000. (237-591) Northern Territory K. Sajdeh, Water Div. Dept. of Transport & Works, P.O. Box 2520, Darwin, N.T. 5794. (895-511) WATER

COME -

VISIT THE WEST

It is hoped that April 1981 will see everyone interested in water and all its aspects heading West to the 9th A.W.W .A. Federal Convention in Perth . Western Australians are firmly convinced that "Eastern State rs" think Australia stops at the border to W .A. A visit to the first Federal Convention held in the West will dispel that view, if it exists, and show how the West is tackling a diverse range of problems in the water and wastewater fields.

More than a decade of rapid population growth and development in Western Austra lia has forced all those concerned to critically examine man y basic permises and become more innovative than in the past. We hope therefore that all delegates to the Convention will learn a great deal from the exchange of ideas in April.

A predominant feature of the Perth region is the sandy coastal plain on which the city is situated. This environment has permitted the widespread use of septic tanks, it provides disposal sites for solid and liquid wastes and ye t, at the same time , harbours a substantial unconfined groundwater resource. This water resource has been increasingly developed for urban water supplies during the I 970's and is the only reason a serious drought has been successfully combatted over the past five years.

In the South West region of the State, long standing problem s of soil and river salination arising from clearing of the land , have escalated. Conflicts in land use management involving agriculture, forestry, water harvesting and conservation have intensified and these have been compounded by the new activity of bauxite mining .

The management and use of water resources is accordingly very complicated and now involves working with full appreciation of the whole hydrological cycle.

Perth and th e West have a great deal to offer the visitor - the situation of the City on the Swan, its friendline ss and its hospitality and in the technical areas , some absorbing and unusual activities. ._ Conventioners will see the extensive groundwater abstraction systems in operation in the Perth area, a visit which will be highlighted by inspection of the Sirofloc Water Trea tment Plant employing magnetic means of water clarification.

Delegates will hear of the work underway on alternative sewer systems in the search of lower costs and of the critical re-thinking and re-appraisal being given the design and functioning of the humble septic tank. A special session will be devoted to the rare but deadly waterborne disease, amoebic meningitis . , Amongst the technical tours will be the opportunity to see a major experiment in groundwater re -charge using secondary effluent. This project, utilising land inflitration, is planned with an eye to possible aquifer re-charge in the future .

With over eighty papers catering to a wide range of interests, with a bu sy and enjoyable social programme planned and with the attractions of Perth and its climate, the 1981 Federal Convention is a must.

CHARLES TUCACK President W.A. Branch

A.W.W.A. MEMBERSHIP Requests for Application Forms for Membership of the Association

should be addressed to the appropriate Branch Secretary.

Membership is in four categories: 1.

Member-qualifications suitable for membersh ip in the Inst. of Engineers, or other suitable professional bodies . ($15 p.a.)* 2.

Associate-experience in the W.&W .W. Industry, with formal qualifications. ($15 p.a.) * 3.

Student. ($5 p.a.)

4. Sustaining Member-an organisation involved in the W.&W.W. Industry wishing to sustain the Associat ion. ($65 p.a.) *P lus State levy where applicable.

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ASSOCIATION NEWS PRESIDENT'S COMMENTS OVERSEAS RELATIONS During recent weeks it has been my privilege to represent this Association in several overseas countries, primarily with a view to strengthening the ties and co-operation between our organisation and other waterrelated bodies. The Queensland Standing Committee has been given the responsibility of External Relations on a long term basis .

New Zealand. New Zealand Water Supply and Disposal Association. The first and most obvious area of co-operation should centre upon New Zealand where, although the numbers of the NZWSDA are not great , the level of interest and of technology is considerable - indeed , we could have a lot to learn from N .z. The main activities of the Association centre upon Auckland , with Mr. Brian Carlisle as the current President. To actively promote co-operation and liaison between water-interested bodies in New L.:aland, the NZWSDA has initiated the Auckland Combined Water Group, consisting of the Institution of Engineers, Institute of Chemists , Academic and Government bodies, and any other interested parties .

This Group maintains a high standard of design , innovation and practical operation in water and waste maragement. Mutual benefits would result from an active liaison which will be cultivated by the Standing Committee . Federal Council will promote further co-operation, both through the supply of our AWW A Journals, interchange of technical data and hopefully attendance at Conferences.

United States of America, Water Pollution Control Federation. AWW A bonds with the WPCF are well established and are further developing in a healthy atmosphere. As an active member of the Federation, our Association is attracting ¡increasing attention, and our Standing Committee would emphasise the excellent representation we have enjoyed through the work of Dr . Trevor Judell, as the present Director for AWW A on the 'WPCF Board of Control.

The WPCF President, Mr. Carmen Guarino and Executive Director Mr. Bob Canham have both indicated their intention to attend the Perth Conference and it is clear that we are by no means behind the rest of the world in technological development - in some areas. we are ahead, largely because our isolation and small population have by necessity made us highly innovative.

It has been suggested by the WPCF that their Journal will promote membership of our 6

Association periodically, through complementary advertising and AWWA will also actively promote WPCF memb ership, which has now been made more straightfo rward with the issue of new membership applications, these are avail able through the Federal Council office.

United Kingdom. International Water Supply Association . Meetings in Lond on with the Secretary General of the IWSA, Mr. Peter Stott, have indicated considerable interest in joint involvement with AWW A and plans are already in hand for the IWSA to be associated with us in the 1983 Conference of this Association . IWSA is a large Association, active in over SO countries, and concentrates its financial assistance in the developing countries . IWSA are looking to Australia fo r the development and cohesion of activities in the Pacific Region .

United Kingdom . Intern ation al Association of Water Pollution Research. There is a most progressive relationship existing both with the Australian National Council and the Parent Body in London . With Professor Dick Engelbrecht as the current President of IA WPR , we can expect even greater cooperation and an invitation has been extended to him to attend our 9th Federal Conference in Perth.

Other UK Associations . Contact has also been made with other professional and learned associations, in the U .K., namely: Institution of Public Health Engineers Institute of Water Engineers and Scientists Institute of Water Pollution Control In the UK , liaison between 'Water Interested bodies' has been mooted and investigated on several occasions in the past, and there currently appears to be some indication of progress in this area. We will maintain contact with these bodies, all of whom are members of the Water Pollution Control Federation , with a view to further cooperation wherever possible. The current President of the Instit ution of Public Health Engineers , Mr. Ted Flaxman , will be amongst the speakers at the Perth Conference.

Australian Water Co-ordinating Committee The AWCC continues to activate liaison with bodies of common interest within Australia. In addition to existing contacts, the Australian Water Resources Council was represented at the last Co-ordinating Committee meeting in June.

The year-end meeting elects Council officers for the ensuing year and formalises implementation of any changes in Branch representation .

Doug Lane of S.A. was elected Federal President and Frank Bishop of Victoria succeeds him as Vice President. Current Office Bearers , members of the Executive Committee and Councillors are as follows: Executive President: Mr. D. Lane (S.A.) Vice President: Mr. F. Bishop (Vic.) Im. Past President: Mr. A. Pettigrew (Q'ld) Hon. Sec.: Mr. P. Hughes (NSW) Asst. Hon. Sec.: Mr. R . Dengate (NSW) Hon. Treas urer: Mr. J. Greer (Vic.) Branch Councillors

A.C.T. Mr. C. Price Mr. R. Badger N.S.W .

Mr. K. Waterhouse Mr. M. Dureau Q'ld Mr. A. Pettigrew Mr. M. Allan N.T. Mr. R. Lloyd Mr. J. Paul

S.A .

Mr. D. Lane W.A .

Mr. D. Montgomery Mr. R. Fimmel Tas .

Mr. H. McPhie Mr. D. Walters

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NEW FEDERAL PRESIDENT At the Federal Council Meeting on November 7th , Doug Lane of Adelaide was elected Federal President in succession to All an Pettigrew. Our new Vice President is Frank Bishop from Melbourne Branch.

Conclusions

These comments are an indication only of the liaison which must be actively pursued with both overseas and Australian bodies. It is my belief that Australia will play an ever increasing role in world water technology and could well form a common meeting ground for major overseas organisations.

ALLAN PETTIGREW

FEDERAL COUNCIL The Council's year ended with a fin al meeting in Sydney on November 7th , held with some difficulty as result of the grounding of planes through industrial problems. However, absentees were few and the usual heavy Council programme did not suffer as a res ult.

l Doug is Manager of the State Water Laboratories of the Engineering and Water Supply Department in South Australia and has accumulated some 28 years experience in the fields of water analysis, quality assessment and management.

Taking his B.Sc. in Adelaide in 1951, his activities have ranged widely over the State sphere, the Australian National area by association with the Australian Water Resources Council, the River Murray ComWAT ER

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mission and numerous other bodies including the Water Co-ordinating Committee and the international scene through membership of supply, research and health organisations dealin g with water and sewerage matters .

In the AWWA he is a Foundation Member and has rendered sterling service to the South Australian Branch over the eighteen years of the Branch existence. He was first appointed a Federal Counc illor in 1973, was Vice President for the last two years and will now have full scope for his knowledge and experience in the vital fields of the Associations activities in the role of Federal Pres ident.

NORTHERN TERRITORY Branch Activities October 24th saw the Annua l Dinner and Ladies Night of the Branch held at the Palmerston Hotel. Twenty couples enjoyed win ing, di ning and dancing followed by a sess ion at the Casino and endeavours to recoup the evenings ' outlay - successfully or oth.erwise is not on record.

T he November meeting, on the 13th, enjoyed a presentation in fo ur parts. Nor m Allen talked on the bacteriology of a potable water supply. Hugh Wil son on water chemistry, Kevin Bowland on the limnology of stored water and David Field on the structure of a water quality assessment programme.

T he final flutter for the year, the Christmas wind-up fu nction is sched uled for December 4th as this issue goes to press. Several films from the Australian Atomic Energy Commissions library will be shown and promise to be of considerable interest to members, guests and the ladies.

T he showi ng will cover expl oration and mining for uranium and the processing of uranium oxide for power generation - all very topical. T he film available includes exploration in the Alligator Rivers region and the produ ction of radioisotopes and their uses.

Territory News

Rapid Creek Recrea1ional Developmenl A community project of considerable interest is the recreational development of the lower section of Rapid Creek , a tidal watercourse, for which the Water Division of the Department of Transport and Works and the Conservation Commission of the N .T . are jointly responsible.

T he development involves a variety of recreational feat ures including a mangrove botanical garden , tropical water garden, restaurant , bike fun park , skateboard bowl and cycle and horse tracks. Construction has commenced.

¡ New Water Supply - Kalh erine Work to replace the hard lime- laden borewater supply to Katherine is well und erway. T he new scheme , taking water from the Katherine at the Donkey Camp area, will cost in the vicinity of $2. 7 million and is scheduled for completion in late 1981.

T he Department of Transport and Works is carrying out the major works by contract.

Design and construction of the water treatment pl ant and associated works has been awarded Willi am Baby & Co. (A ust) P / L. WATER

Further contracts have been let to S.B .S. Constructions P / L for construction of 6 km of 450 N.B. pipeline and to Steelcon Constructions P / L for construction of the pumping station and associated works .

Tubem akers of Australia Ltd. supplied the ductile iron concrete lined pipe for the rising main .

Ma ry Ann R ecreational Dam A dam and water recreational area provided by the Northern T erritory Government for Tennant Creek was completed earlier this year . T he project was designed by Consultants G.H. & D. and the major contract was awarded to McM ahon Construction P / L in September 1979.

Constructed at a cost of $800,000, the rock fill d am has a ten metre high concrete face and impounds 451 megalitres with an average coverage of 8 .5 ha and maximum of 17.4 ha.

Boat ramp and tra iler park have been provided and an access road from the Stuart Highway. While this water recreational area is small , it is of great value in this arid region and a significant contribution by the Government .

TASMANIA At the AGM on September 24th , Mr. J. Lawrence was elected President for the coming year, succeeding B. Healey. This was the only change in th e 'establishment' of the Branch .

In a most interesting talk , Mr. J. R. Ashton , Commissioner of the Hydro Electric Commission who has just returned from overseas, spoke on his attend ance at the World Energy Conference in Munich . The purpose of the Conference was consideration of the world energy situ ation and the rising trend in energy demand. After commenting on these aspects , Mr. Ashton followed with an account of alternative energy source studies in various countries.

A.C.T. In August , Dr. Allan Wade of the Commonwealth Department of Health gave the Branch a review of the current thinking on the epidemiological and toxicity aspects of potable water quality criteria under the title 'Safe Water'.

T he Branch AGM was held in October and the incoming President , Ron Badger expressed to David Philp the appreciation of the Branch for his services as President during a difficult year. Dr. Ron Rosich is Vice Pres ident, Jim Coucouvinis Secretary and Mike O' Keefe , Treasurer.

After the formalities, Dr. Peter Tyler provided some light relief with 'tall tales and true ' of Lakes Meronictic and Caldera in south -western Tasmania.

During the past year there have been a number of changes in Branch membership due to transfers and relocations including the moves of Werner Padarin and David Henry to Indonesia.

Allan Hatfield , after many years of innovative and outstanding contribution has moved out of the water industry and will be missed by his many associates in this area.

WESTERN AUSTRALIA The AGM for the 'W~ t' yielded the following changes in the Committee structure : President is Charles Tucak, Secretary Treasurer, R. Loo and Committee members are Dr. G. B. Hill and Messrs. D. Montgomery, K. Nelson , B. Sanders , B. Robbins , J. Katric , R. Fimmel, R. Mercer and N. Platell.

The forthcoming 9th Convention is tending to dominate Branch activities. Preparations are proceeding smoothly, papers submitted are numerous and of excellent standard, interest is of high order and it is said that the Conference tour of the Swan Brewery may be marked by a special brew to highlight the occasion.

QUEENSLAIS.D At a Symposium on September 12th with the topic of 'Design Frontiers In Water and Wastewater Treatment' some SO registrants had a rewarding afternoon with speakers describing both research and practical aspects of new methods of water and wastewater treatments. Details and copies of papers are available from the Hon. Sec. AWW A, P.O. Box 668K, Brisbane, 4001.

At the October meeting on the 22nd, formal approval was given to the proposed new ByLaws to be submitted to Federal Council after debate as to the necessity for revision of the existing By-Laws .

The formal business was followed by a most interesting talk by Mr. Evan Richard on 'The History of Brlsbanes Drainage System'. Mr. Richard, now retired from the B.C.C. as Investigations Engineer has researched the subject for many years and his talk and collection of maps, posters and slides was fascinating . There was a suggestion that Mr. Richard and Geoff Cossins could , as co-authors , produce fi most interesting coverage of the City's water, sewerage and drainage systems.

The final function for the year, the traditional Christmd gathering was again very generously hosted by Commonwealth Industrial Gases through Keith Strickland, Manager of Environshield (Q'ld). C.I.G. personnel demonstrated what can and what can't be done with gases - all followed by an enjoyable meal with Christmas Cheer gaseous or otherwise - and warm appreciation of C.I.G.'s hospitality.

SOUTH AUSTRALIA Branch Activities At the Branch AGM on September 26th, Moss Sanders was elected President and Bob Clisby, Vice President. Tony Gatz is Secretary and Mary Drikas Treasurer also continuing her role as Correspondent for 'Water'. The Committee is Arthur Greenhough, Paul Harvey, Charles Hulse, Doug Lane, Kevin Trevartin and Gavin Wood . Doug Lane and Moss Sanders are Federal Councillors and Mr. D. Orchard was appointed Branch Auditor.

Branch membership increased by a net seven with five new Sustaining Members Selby's Scientific Ltd ., Townson and Mercer (Distributors) P / L, Commonwealth Industrial 7

Gases Ltd., the Department of Mines and Energy and Santos Ltd. A fascinating and informative evening was provided by Mr. Gordon Robinson , Chief Hea lth Surveyor of the S.A. Health Commission and Mr. Terry Grirnrnond, Chief Microbiologist of the Flinders Medical Centre on the subject of 'Water Use In Hospitals and the Food Industry'.

Mr. Robinson discussed the use of water in the fluid industry with some fascinating glimpses of 'tricks of the trade' in the industry. 'Caveat emptor ' was the message.

Hi s pragmatic definitions included -'sausages, a stable emulsion of protein, water and fat ' and mayonnaise - 'a sta bilized water and oil mi xture'!

Mr. Robinson stressed the importance of safe chlorinated wash water for operators and the need for vigilance and quoted the introduction of the 'Aberdeen Typhus' by corned beef canned in Argentina. The cause here was an inoperative chlorinator, unbeknown to operators and a coincidentally faulty gasket which allowed the cooling cans to take in contaminated cooling water.

Mr. Grirnrnond discussed water usage at Hospitals and in particular the Flinders Medical Centre . The predominant use is for the gardens , the water for the hospital proper being chemically treated , softened and redisinfected before distribution . Dernineralised water is used for analytical purposes and the Pharmacy Section produces irrigation fluid for the washing of external wounds.

He described problems encountered including the reduction of chlorine residual in water in an operating theatre due to a build up of algal sludge in storage tanks and contamination arising from bacterial growth on floor mops .

The final event in the 1980 programme on November 28th was a talk by Mr. Warren Banython, 'A Walk Through the Flinders Ranges'. The speaker lived up to his reputation as a well travelled, well-informed and entertaining conservationist and did full justice to his picturesque subject with excellent slides .

State News

Water Filtration for Metropolitan Adelaide The Engineering and Water Supply Department is well advanced with its programme of providing filtered water to Adelaide and its suburbs . The first plant, Hope Valley with a designed capacity of 273 ML/day, was opened in March 1977 and serves the N.W. area of Adelaide. Th e Anstey Hill Water Filtration Plant, opened in March this year, supplies the N .E. suburbs and has a design flow of 313 ML/day. The Barossa Plant, with a capacity of 160 ML/day is now about 70% complete (Commissioning programmed for Oct. 1981) and will serve the northern suburbs and Elizabeth - Salisbury satellite towns.

In conjunction with the Barossa plant, the Little Para Plant will serve the Elizabeth Salisbury area (mainly in summer). This plant has a designed capacity of 160 ML/day and is estimated to cost $16.9 million and to be operational by September 1983. Excavation is complete and Dillingham Australia Ltd. recently commenced work on the first civil 8

contract . Finally. the largest installation will be the Happy Valley Water Treatment Plant to serve the southern suburbs . The design is complete and earthworks are programmed to commence late in 1981 with compl etion of the project in 1988.

Brukunga Acid Neurralisation Plant Officially opened on September 18 by the Hon . R . Goldsworthy , Deputy Premier and Minister of Mines and Energy, this plant will overcome a serious pollution problem from the Nairne Pyrites mine which operated between 1955 and 1972.

Rain and ground water passing through the old mine workings , rnullock heaps and tailings darn become highly acidic and laden with heavy metals . A diversion scheme constructed to collect the seepage and return it to the tailings darn proved ineffective and resulted in severe pollution of Darvesley Creek running into the Bremer River. The Neutralisation Plant and proposed revegetation. grading and sealing will permit the Bremer to be used safe ly for water supply.

Happy Valley Trunk Sewer System This $6.1 million scheme for a major trunk sewer to serve the southern suburbs of Happy Valley, Reynella, Aberfoyle Park and the Corornandel Valley is a complex project . Now about 70 % complete, the estimated finishing date is mid 1983 although partial commissioning may occur before this time .

Personal Para's Doug Lane, the newly elected Federal President recently returned from a private overseas trip. He attended the thirteenth International Water Supply Association Congress in Paris and the OECD Environ mental Protection Agency Conference in Portland , Maine, USA. He also visited water authorities in USA and Canada.

Roger Stokes, Manager Investigations and Technical Policy Branch of the E. & W.S. Department has resigned after 22 years service to commence his own consulting organisation.

NEW SOUTH WALES Branch Activities The Branch's premier social event, the Annual Dinner Dance on September 19th, provided a pleasant occasion at the Silver Spade Room, Chatswood . A contrast to the technical fare of the year was a most enjoyable after-dinner talk by Tim Read , Producer in Chief of Film Australia and a sensitive musical background by the 'Moby Disc' maestro and his electronic hurdy gurdy.

At a joint meeting with I.E. Aust on November 5th , some sixty gathered for a presentation on 'Vacuum Sewerage Systems - Metropolitan Applications' by Marshall Whyte (Inspecting Engineer, Investigations, MWS & DBd) and Jack Child, Manager, Environmental Systems Division, Electrolux.

The vacuum system is one alternative developed to provide sewerage at lower costs in urban areas. The system described was installed at Sylvania Waters, an estuarine 'keys' development where ground settlement up to one metre has been encountered .

The basic Electrolux system (vacuum valve at the sanitary fitting) has been modified to

meet the Board's requirement for conformity to standard sewerage practice . Co-operation between the Board and Electrolux was a feature of the project and the system holds promise for application in rocky and intractable terrain .

Also on November 5th, the joint A WW A and WRFA Symposium on 'Water Supply Demands In Towns and Cities' drew an interested audience of some 115 for a comprehensive programme.

Papers and discussion at and following the Symposium are available in bound form ($12) from the Conference Secretary R. R. Ash, 37 Boronia Ave. , Cheltenham 2119.

For his effort in almost single handed organising this highly successful event to Dick Ash the sincere thanks of both Associations.

Future programming includes: • Christmas Party, Dec. 12th at ' La Maison' • January inspection of M.W .S. & D.Bd. Sewage Treatment Plant either at North Head or Warriewood • February (tentatively), talk on 'Biological Aspects of Water Management and Control

by Fish Toxicology Testing' • Regional Conference Hunter Valley, March 6-8.

State News Item Neville Rees of the Water Resources Commission of N .S .W. has recently been appointed Commissioner. Arthur Tilly, Dep. Engineer in Chief - Investigation and Survey of the M.W.S. & D.Bd. has retired; Ken Aubrey replaces him and is succeeded by Marshall Whyte, (previously Investigating Engineer, Sewerage). All three are Members.

Water Treatment at Tamworth The City Council's Water Purification Plant was opened on August 29th by the N.S .W. Minister for Public Works, Mr. Jack Ferguson ; cost of the project was $6.9 million.

The plant is designed for an initial throughput of 68 ML/day (45,000 people) with provision for enlargement to 93 ML/ day (60 ,000 people) and to provide: • Separate or, common treatment of water from Dungowan Dam and the Chaffey Dam , and pumped from the run-of-the-Peel some 40 km downstream of the dam.

• Treatment of Dungowan water generally by direct filtration following coagulant injection, flash mixing and detention.

• Treatment of Peel water , generally by coagulant injection, solids contact clarification and filtration.

• Classification and filtration enhancement by polyelectrolyte. Dual media filtration anthracite over sand and gravel.

• pH correction , chlorination and fluorida tion .

• A large pumping station housing backwash pumps and two sets of high lift pumps (water cooled 3.3 kV) .

The Department of Public Works designed the electrical system and plant control system utilizing computerised control , and the slude lagoon system and landscaping. The Department also supervised and co-ordinated construction .

Gutteridge Haskins and Davey was responsible for investigation, design and specification of the civil, building and plant items.

WATER

The major Contractors were: Graham Evens, Gatic-Fuller, Actral, Honeywell, Weir Engineering, and Edmunds Moir, with Peel Cunningham County Council on the electricals.

VICTORIA As tradition dictates, the Annual General Meeting in September was followed by an address from the retiring President. Bob Swinton filled the bill with a description of the work the CSIRO is doing with its industrial collaborators, ICI and Davy-McKee, in the development of a new technique of continuous ion-exchange, using the unique properties of magnetic micro-beads. He defied McNamara's Rule (that the chances of a demonstration going wrong are proportional to the number of onlookers) by mounting a successful piece of showmanship , with absolutely nothing up his sleeve. To be continued at the Perth Conference.

The Spring Break-out in October was held in conjunction with the Centenary of the Ballarat Water Commissioners. It was ev.erything one could wish for . . . two beautifully sunny days in delightful and interesting surroundings. The Friday evening rendezvous at the Commission's Office (rated National Trust) was admirably hosted, and Bob Ford, from dusty files and cupboards mounted a superb historical exhibition. The quality of draughtsmanship . . . even art ... in some of these hundred-year old drawings was mind-boggling. Many an engineer was heard to mumble . .. 'wish the young blokes in the office could see these.'

On Saturday the conference was held within the Sovereign Hill Historical Township. To wander up the deserted street at 9 a.m. before the gates were opened to the tourists, saunter up the boardwalk, then climb the stairs of the United States Hotel to a plush and chandeliered meeting room was an experience in itself. There was nothing old-fashioned about the papers though: • Anaerobic treatment of potato processing wastes, by J. Parker • Pollution levels in urban run-off, by C.R. Weeks • Nutrients in the Latrobe catchment, by G.J. Pooley.

Then through the forests to the Creswick Forestry School, superb gardens and cricketon-the-village-green thrown in. Back at Sovereign Hill for a dinner dance at the New York Bakery, with floorshow ably(?) provided by some very eminent members of the water industry with aprons, moustachios and all.

Outside the full moon silhouetted the huge poppet head and lit the ancient shop-fronts . . . how the sounds of those old songs must have echoed.

Sunday saw a return to history. Neil Andrew talked of his search through the Commission records, dwelling particularly on the politics of the water supply in the twenty turbulent years between the discovery of gold and the relatively sedate 1880's. He illustrated his talk with tattered-edged old plans, and newspaper reports of the stand-up fight between Ballarat (Government and Commerce, sitting on the water supply) and Ballarat East (where the action was, on the WATER

diggings). One wonders how much the Eureka Stockade was prompted by lack of a good water supply.

The a paper with a difference ... water at $300 per kL. A.C. Laing of the Department of Minerals and Energy r'eported on the current revival in mineral waters, now grossing over three million dollars per year in the Daylesford region, giving sanguine estimates of their formation and value.

Further details of courses are available fromThe Manager, Operating Training Centre, P.O. Box 409, Werribee 3't>30.

(03) 741-5844.

VICTORIAN CONFERENCE SEWERAGE ENGINEERS AND OPERATORS

Victoria's Spring Break-out luncheon at Moorabool Reservoir.

The final barbecue overlooking the Moorabool reservoir came at the end of a delightful car tour through the wooded catchment areas of Ballarat. All in an, a tremendous credit to the local organisers, Alan and Audrey Howard, Bruce Price and Bob Ford.

Robin Povey arrived back from his scholarship tour of U.K., and instead of going straight back to his old job as Secretary, was promptly promoted to Vice-President .. . handing over the secretary's job to John Park (same address) The Victorian Branch has presented a perpetual trophy to the "Treatment Plant Operator of the Year" . Stan Franzi was awarded the trophy this year at the Engineers and Operators Conference at Werribee.

One more paper to come in this year's programme on the Use of Water for Fire Fighting ... a subject neglected by most of our members. Barry Lee, of Wormald International will discuss the problems . . . particularly in high-rise buildings, on November 26th, as we go to press.

OPERATOR TRAINING EXPANSION IN VICTORIA The Ministry of Water Resource and Water Supply is continuing to expand Operator Training through further activities at the Operator Training Centre at Werribee .

The already established programme includes regular Level I courses for Operators of municipal wastewater Treatment plants, extended aeration package treatment courses and chlorination courses for the operators of both water and wastewater plants.

Adding to these, the Centre recently conducted two, one day seminars on chlorination for management personnel drawn from the Victorian Institute of Water Administration and in the near future will introduce a basic course for Engineers included with wastewater treatment.

This years Annual Conference - the 43rd - and now under the management of the Victorian Ministry of Water Resources, attracted a record 226 delegates to Geelong on October 23rd and 24th.

Engineers and Operators from Victoria, Queensland, South Australia and Tasmania met to examine and discuss topics with the central theme of 'Sewerage and the Public'.

After opening remarks by the Hon. Glyn Jenkins , M.L.C., probably the highlight of the technical sess io ns was a thought provoking panel di scussion on 'Pub li c Relation s and the Wastewater Industry'.

The keynote address "Engineering Works, the Environment and the Public" was given

by Mr. W. P. Dunk, Assistant Director (Assessments) of the Ministry for Conservation and stressed the harmonious combination of these aspects through proper planning and execution.

Stan Fra nzi (right) receives the Operator of the Year Award from Vic. Branch President, Alan Longstaff.

An innovation was the presentation for the first tim e of an award by the Victorian Branch of the AWW A for the 'Operator of the Year'. This will be an annual event and is prompted by the interest of the Branch in continued involvement with the practical aspects of the water resources industry and with the Committee of Management for Operator Training.

The Award recording will be maintained on a large shield to be held at the Training Centre at Werribee, recipients of the award wi ll receive a small replica of the shield.

The initial Operator of the Year is Mr. S. J. Franzi, Operator in Charge of the Melbourne Board's Western No. 2 Purification Works.

Stan Franzi is outstanding in hi s field and has been seconded to the Training Centre for fifteen months to assist in developing the early Operator Training Courses. The award was presented by the Vic . Branch President, Alan Longstaff.

Next year's Conference will be at Mildura.

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RETIRING PRESIDENT REPORTS As my term as Federal President has drawn to a close, it is my pleasure and privilege to report to you on the progress o.f the Association over the past two years, and to welcome the new President, Doug Lane, to this office.

The small group of people who originally laid the foundations of the Association must indeed be gratified by the progress in somewhat less than 20 years. The features which initially made the Australian .Water and Wastewater Association "different" from other learned bodies are precisely those which now lend themselves to its further development, namely, the fact that we encompass many professional disciplines associated with the Water field , many and varied Government and Commercial interests , and the enthusiastic support of International affiliates .

Membership

The growth of numbers is a clear indication of the increasing standing of the Association. Some States have had increases of 20%, ranging to Northern Territory whose membership has doubled.

However there is some danger in the numbers system as a gauge of effectiveness, and it is even more important to look at the Membership growth from the point of view of the continued support of those new members, their attendance at and participation in our activities, and the overall balance of professional , multi-disciplinary, associate, student and industrial interests.

Association Name

Periodically the name of the Association comes up for review , both at Federal Council and at Branch level. The response has been considerable, and the concensus once again has been that whilst the A.W .W .A. has some shortcomings of nomenclature, it does at least convey even to the unitiated the widest meaning of our activities. Most members feel that our name should be left as it is, and our energies expended on furthering our cause rather than changing our title.

Communications

For those members who devoted much time and effort to the conception and production of the Journal, the past year has been a fulfilling one. The Association now has a paid editor for the Journal 'Water' which after some turbulence is now publishing on schedule and producing a high standard document of use to our members. This ~an and will be improved by constant support from members by supplymg the editor, Mr. G . Goffin, with articles and general information from all over Australia and overseas. What is common knowledge for one group is news for another.

The success of the Journal depends upon the fullest support of its members. It is a truism that people invariably have more inclination to be critical than to be constructive. If you have a comment, by all means make it - your letters are most welcome to the Journal Committee.

If you have a criticism, it too is welcome - but let it be a constructive criticism. I have yet to hear that the Journal Committee were inundated by so many letters that they had to run an extra page.

Technical data being published is tending more towards the innovative , and after a recent review of overseas activities in our field, I am convinced that we in Australia have a great deal to offer in this regard. Because we are a limited population, we cannot build bigger, but we can certainly manage better, and much of this increased efficiency is coming from the application of new concepts, or the adaption of existing ideas to new circumstances . Our Journal is our mouthpiece, and new ideas should be promoted. ¡Conferences

Our Conferences are great areas of communication, and whilst we acknowledge that there is a danger of too much talk and not enough action , the interchange of data and introduction of new concepts are the lifeblood of the Water field. The forthcoming Conference in Perth gives every indication of being an outstanding success, and is attracting considerable interest from affiliated bodies overseas.

Australian Water Co-Ordinating Committee

1980 has seen the establishment of the Australian Water Coordinating Committee, on the initiative of this Association. This is not just another organisation, but a Secretariat to co-ordinate the activities

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of affiliated bodies . We seek to provide a forum specifically for like organisations and learned bodies to plan and promote conferences, seminars and talks in a thoughtful manner so that Australia's limited resources are not abused, but used economically.

Affillated Associations

A profusion of initials quickly becomes a .confusion, considerable efforts are being made at Federal Council level to further ~ur co-operation with the International Association for Water Poll~tton Research Water Pollution Control Federation , and the International Water Supply Association together with other Nati?nal and International water - related organisations. It is also essential to keep in mind that we are a Pacific Region country, and to look at our activities in this context, and in the context of Asia and China, their proximity to us, together with like climatic conditions, problems and solutions.

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Activities

The Annual Reports of the State Branches highlight the many and varied activities and the increasing interest of Members. Most branches are now conducting Annual Seminars and / or Regional Conferences.

N.S.W. Branch held a most successful conference at Goulburn, while Victorians "Broke Out" at Ballarat at the onset of spring. Tasmania makes a feature of the A.G .M . and Annual Dinner , Northern Territory has been very pleased to have a series of speakers from Industry to address their meetings - this is most helpful to the smaller branches.

South Australia hosted a most successful Summer School, Queensland mounted the 8th Federal Conferences, whilst Western Australia is very well organised to hold the 9th Conference. There is interest in the formation of regional branches in several states.

These are just a few of the multitude of meetings, dinners , seminars, inspections, environmental studies, training courses which the branches have organised and supported. Enthusiastic Committees and dedicated people are working in varied ways for the dissemination of knowledge which is our essential motivation.

Rules and Bylaws

In an effort to keep abreast of the changing needs of the Members, the Federal Council recently initiated an updating of the Rules of Association; several of the Branches have also reviewed the bylaws and made update alterations. Whilst it is usual for an Association such as this to suffer some "growing pains" when membership reaches the 2000 mark on a National level, it should be noted that the basic changes required are not major, and tend 11\ostly to as~ist the smooth management of our affairs. It is a tribute to the far-sightedness of the foundation members that in the present era of rapid change, our original concepts for the Association are still highly applicable.

In conjunction with this updating, a new A.W.W.A. brochure has been produced , and our thanks are due to the N.S.W . Standing Committee for their excellent presentation . I would urge all members to re-read the aims and objectives contained in this brochure, and to actively promote and support the Association.

Federal Council

During the past 2 years the Federal Council has continued to meet each 6 months; with the growth of the Association, the executive felt it necessary to meet more frequently. Six meetings have been held during the past 12 months, together with the formation of the Standing Committees on essential aspects of the Association's function , to ensure that no areas of potential activity are neglected .

I am most grateful for the support which these Standing Committees have given, and for the considerable discussion and diversity of opinion which ensues at Federal Council level, as the representatives of the Branches express their views and opinions . This results in healthy growth and constant review , and augurs well for the future of the Association.

To the many people who have contributed ideas and support, encouragement and advice, and in particular to Peter Hughes, Federal Secretary, my sincere thanks.

ALLAN PETTIGREW Federal President WATER

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THE PHILOSOPHY OF AUSTRALIAN WATER .LEGISLATION PART II Sandford D. Clarke 2. GROUNDWATER 2 .1 Common law principles concerning groundwater The development of common law principles concerning groundwater is often ascribed to prevailing ignorance by scientists and judges alike , of the behaviour of percolating groundwater. There is no shortage of judicial statements consistent with such an hypothesis . One of the most qu oted is from an Ohio case in 1864, Frazier v. Brown: "The existence, origin, movement, and course of such waters , and the causes which govern and direct their movements , are so secret, occult and concealed that an attempt to administer any set of legal rules in respect to them would be involved in helpless uncertainty, and would be, therefore, politically impossible. " 11 Perhaps ignorance contributed in part to the complex rules which emerged, but there was also , doubtless , reticence on the part of the courts to interfere with what was perceived to be the natural rights inhering in land.

Thus the common law rules are primarily marked by a conceptually significant, but practically insignificant, distinction between underground rivers (which attract the riparian doctrine) and percolating waters. The former apparently flow rather more frequently in the law reports than they do m practice. The second characteristics of the common law rules is the so-called "absolute right" of the overlying owner to use percolating groundwater beneath his land to any extent, and for any purpose , he pleases - irrespective of the harm this may cause to other well-owners . In England, at least, this absolute right can be asserted, even if one's motive for pumping is purely malicious and intended to interrupt one's neighbour's supply. The rules , as they exist, can be summarised as follows .

2.1.1 Underground rivers (a) Known and defined channels

An overlying landowner is restricted in the use he may make of groundwater drawn from an underground river, the course of which is both known and defined.

In Australia, it has been held that a course will be known and defined if " its existence is demonstrated by excavation or can be inferred from observable facts, e.g. where a surface stream disappears underground and emerges again lower down the slope, but the onus is on the plaintiffs to prove that the abstraction complained of is from a kn ow n and defined channel."

In such a case, the ordinary riparian rights doctrine applies, limiting the amount which may be taken for other than domestic and stock purposes and creating the obligation to let the water flow , substantially undiminished in quantity or quality.

A lower owner who is riparian to the stream - whether surface or underground , at that point - may sue an upper overlying owner who exceeds his riparian right for an injunction and for damages . He may obtain an injunction even if he has not actually suffered damage as a result of the defendant's use. (b) Where the channel Is not known

It is possible that water may flow in defined underground channels and scientific evidence may establish its existence beyond doubt. It will not be " known " in the legal sense, however, unless an ordinary, reasonable man would have been able to conclude that there was an underground channel by studying the physical appearance of the area.

Where the channel is not "known" in the legal sense, the riparian doctrine does not apply. Water in such underground rivers is subject to the same rules as percolating groundwater.

2.1.2

Percolating groundwater

(a) Rlght to extract groundwater

The Author is Harrison Moore Professor of Law at the University of Melbourne. This paper was presented by Professor Clark at the A WAA Summer School in Adelaide in February /980.

Part I of rhe paper was published in the September issue of Warer.

Parr Ill will follow in the March issue, /981.

WATER

An overlying owner, although he does not have property in water percolating beneath his land, has an absolute right to take such water in such quantites and for such purposes as he sees fit.

Under English law, the purpose for which water is taken need not be beneficial and need not be related in place or purpose to the use made of the overlying land . To take water, with the sole intent of depriving one's neighbour is not illegal.

Under Australian law, this absolute right may be somewhat limited, by reference to a standard of reasonableness. To extract water with the malicious intent of harming one's neighbour would probably not be permitted . It is impossible to predict, however, whether reasonableness will intervene to diminish other aspects of the overlying landowner's absolute right to use.

Although percolating water is not the property of the overlying landowner, once it filters into his well it is reduced into possession and is subject to ownership. (b) Position of other overlying owners

A neighbouring landowner , whether or not he has a well which is adversely affected by the pumping of the overlying owner, is unable to sue. While he , too, can extract such water as percolates beneath his land he cannot sue a neighbour whose pumping prevents water from percolating to his well.

Again, it is possible, but by no means certain, that Australian courts may qualify the English rule and allow an action where the pumping which interrupts supply is done with malicious intent, or is deemed to be unreasonable in some other respect.

The same rules which prevent an action apply, whether the interference is caused by pumping water percolating towards a neighbour's land, or by extracting water from beneath the land of a neighbour. Immunity in the latter case applies only between neighbouring landowners in Australia, but will apply, even if the extraction causes neighbouring land to subside.

To distinguish this rule and to allow a remedy where land does su bside , the courts sometimes find that a mixture of, say, sand and water has been removed - and thereby escape the rule, which only applies to groundwater. f A neighbouring landowner will be able to sue, however, for any activity which leads to the pollution of groundwater percolating beneath his land. The rule has been long-established, although recent developments in the law of nuisance may cast some doubt on the precise scope of this remedy . To maintain an action for an injunction to prevent the pollution of groundwater, it is uncertain whether the plaintiff must prove that he has suffered, or is about to suffer, actual damage. The same uncertainty, which arises from certain aspects of the riparian right at common la,w , also affects the question as to the circumstances in which continuous and unchallenged pollution of an underground source may give rise to a prescriptive right to continue polluting - quite apart from any statutory provisions which may prohibit such pollution. (c) Position of landowners riparian to adjacent streams

A riparian landowner can only assert his general common Jaw riparian right against an overlying owner whose well interferes with the flow in a surface stream, if the well is pumping from a "known and defined" underground channel.

Where there is no "known and defined" underground channel, a distinction must be drawn between influent and defluent waters. A downstream riparian will have no action to prevent the extraction of influent waters by an overlying landowner. On the other hand, reason, if not authority, should allow him to sue if the overlying owner pollutes water influent to a surface stream.

Where the effect of pumping from a well is to draw-off water already flowing in a surface stream, the position is otherwise. A downstream 11

riparian may sue for an interruption to the customary flow where water is drawn-off "directly" from the water-course into an adjacent well or excavation. Where the effect is not so "direct" and is attributable, say, to a general drop in water-table due to pumping, no remedy will lie .

The distinction, as a matter of hydrogeology , may be difficult, if not imposs ible, to maintain , and there is doubt whether the rule applies to percolating water, but it appears to be firmly established by early English cases wh ich have not sub sequently been judicially cricitised in eith er England or Australia .

2.2

The philosophy of Australian groundwater legislation

2.2. 1 Controls over construction At the risk of oversimplification, the first pressures for legislative intervention were to permit Crown moneys to be expended on the development of artesian and sub-artesian wells in New South Wales, but the rapid expansion of private drilling of deep artesian wells in Queens land and New South Wales after 1887 quickly produced a situation where loss of artesian flow became apparent. In 1906, New South Wales legislation recognised a need to "guard against indiscrimin ate borings or the waste of the water" and required licences for new artesian wells. Further, the development of cement casing techn iques and elimination of problems of corrosion indicated that control over the ma nner of construction would reduce both problems of wastage and transference between aquifers.

The early legislation of this century in New South Wales, Queensland , Western Australia and South Australia was thus primarily concerned with excess ive waste and , inferentially, long-term conservation . It was not intend ed to interfere with the absolute right of the landowner to use water as he pleased, nor even to bring about more eq uitable distribution of available supplies - although Queensland ultimately introduced provisions to allow an order to be made that excess groundwater be shared with neighbours. Controls were thus initially aimed purely at construction , not at use and applied primarily to artesian bores where un capped wells produced conspicuous waste.

There was certa inly no intention to assert a supervening State right to control the use made of groundwate r . 12 In retrospect, this may be seen as showing a desire not to interfere unn ecessarily in the landowner's enjoyment of land and its natural advantages - perh aps in recognition of the common law right of the overlyin g landown er to use such groundwater as he could win for any purpose he saw fit.

2.2.2 Controls over extraction of ground water Modern hydrogeology, of course, points to many reasons why controllin g the extraction from all bores is also justified. Over-pumping can ca use undue depletion of the resource , often associated with adverse effects du e to aquifer or surface subsidence, or can equally cause saline intrusion or contamination, the effects of which, if not irreversible, may take many years to eliminate. Modern political and soc ial th eory add furth er reasons to control extraction. Although economic factors can occasionally justify a conscious decision to mine an aq uifer, political factors generally seek to promote the stability of development in particular areas. There is thus often a desire to protect existing investment against the consequences of draw-down beyond the reach of ex isting bores, or the potentially harmful effects of using bores for drainage or waste-disposal, and to place controls on the use made of both existing and new bores to ensure the continued viability of the resource. In direct contrast, political factors may also sometimes dictate that existing uses give way to some new use which is perceived as more socially or economically desirable, such as public urban water supply . A conditional licensing system , which subjects the extraction of water to controls and allows the possibility of varying, restricting, or even revoking the conditional right to extract and use water , allows many of these objects to be achieved.

The reasons just outlined point to a vigorous and comprehensive system to li cence all extract ion of wate r and it must be remembered that, in relation to surface-wate r, we have become well-acc ustomed to a syste m of ad min istrative apportionm ent of rights . Nevertheless, the in tensity of gro undwater development differs from State to State, and there are differences in the degree to wh ich the socia l object ives mentioned above are perceived as politically acceptab le. There are thus differences in policies between the States, as revea led by their leg islation. although th e newer generation of ground water legis lation in

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South Australia , Tasmania and Victoria are generally similar in scope. 13 The transition from mere control of bor construction to the imposition of controls over extraction is marked by several distinct phases. As previously mentioned, early legislation was primarily concerned to control the construction of artesian bores. Thus, Queensland and Western Australia still retain a system whereby control, even over the constru ction of sub-artesian bores, is only poss ible in certain declared areas.The licensing provisions in each case initially adhered to the acts of constructin g, en larging, deepening or alterin g a bore, and were not concerned, on the face of it, to regulate the use made of the water , other than to prohibit waste. Originally, the permit to construct a well seemed to be the only administrative threshold requirement; thereafter , the right to extract would continue as an indefinite entitlement, for whatever purpose the overlying owner chose. There were limited or doubtful powers to intervene, or to cancel a 1icence, once issued. There was certainly no intention that the continued use of water wou ld be closely monitored - or that rights of use would be subject to adjustment or qualification.

The criterion of intended use seems to have had its first regulatory impact in relation to the absolute and conditional exemption of bores from licensing requirements. Thus, some legislation exempts bores supplying water for domestic and stock purposes. This exemption doubtless owed someth ing to the ordinary common law right of the riparian owner to take surface-water for such purposes (which had been preserved under surface-water legislation) , but the exemption nevertheless established th e purpose of use and, inferentially, the quantity of use as relevant criteria to determine what bores should be reg ul ated.

The need for data as to the quantity and occurrence of ground water - in order to permit more expeditious location of sources for future bores, rather than to control existing users - led to the imposition of certain requirements concerning the reporting of use . It became customary to require in formation as to the proposed purpose and, sometimes , volume of use as part of an application for a construction permit.

The next identifiable purpose of regulatory intervention in the use made of water was to control waste and pollution. Both the New South Wales and Queensland Acts prohibited waste from artesian wells and gave powers to direct remedial action, although they conferred no powers to intervene.

Even the limited desire to control waste and pollution was eventually suffi cient to justify the imposition of more striQgent controls over use .

Thus the Underground Waters Preservation Act , I 959 (S .A.) allowed direct ions to be give n to deal with contamination and includ ed the power to restrict the amount of water taken. It further provided for the variat ion of conditions attaching to pe~mits.

The next phase in development marked an important change in the phi losophy of regu lation and a complete abandonment of any lingering influence of the absolute rights accorded by the common law. The alterations to the South Austra li an Act in 1966 and 1969 typify this change in emphasis. Whereas the I 959 Act provided that permits remain ed in force until revoked, the 1969 Act lim ited all permits to twelve months duration. The powers to grant and revoke permits, to attach terms and conditions, and to give directions were, after 1966, no longer merel y exercisable to control waste, contamination and deterioration. but cou ld also be used to prevent the inequitab le distribution groundwater and the undue depletion of supply. This amo unted to statutory recognition of the potential interest of both ex isting and future generations in the continuance of the resource and a supervening interest of society in ensurin g that it is duly apportioned among potential users. Nothing could be further from the common law pos ition.

This does not mean that the security of existing users is necessarily abandoned . The first purpose of a licensing system is to ensure stability of ex isting development and, indeed , some Acts envisage that conditi ons wi ll be attac hed to licences in order to ensure that supplies of other users will be protected. While legislation of this phase thus protects ex isti ng uses, there are also libera l suppl ementary powers to declare protected areas where more intensive controls may be applied; to vary. revoke or ca ncel cond itions attached to licences; to refuse to renew licences on expiration; to impose quantitative restrictions on pum ping: and to give directions and to intervene in the even t of fai lure to comp ly.

Al l th ese provisions. in combinat ion , generally all ow great fl ex ibility WATER

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I,

in the formulation and implementation of policies and potentially subject uses to qua li fication in the public interest. Such, or course. is logica lly consistent with the fundamental vesting provisions in the majority of Acts which confer on the State a supervening right to the use of all groundwater.

The regulation of groundwater use, at least in the eyes of the hydrologist, most probably reach es the highest point of sophistication where. cons istent with the unity of the hydrological cycle, it achieves the planned conjunctive and complementary use of surface-water and grou ndwater. Accordingly, a 1974 amendment to the Victorian Groundwater Act 1969 probably marks the highest philosophical attainments of Australian groundwater legislation. In deciding whether to grant a licence to extract water, the State Rivers and Water Supply Commission must consider, not merely whether sufficient groundwater is avai lable, but the quantity of water from other sources which is ava ilabl e to the applicant, and the effect of granting the app lication on the supply of other water users , whether they are supplied from surface or groundwater. 14 As already suggested. the legislation of the Australian States differs in the degree to which it contains provisions directed to controlling the use made of water. In New South Wales, Queensland, Western Australia and Tasmania the only licence required is a single construction permit. This does not mean , of course, that the use of grou ndwater is unregulated in those States. lt means, rather, that such controls as do ex ist are imposed by the terms and conditions attached to construction permits, instead of through statutory provisions related to use. The legislation of Victoria and South Australia is in a very different mould. In Victoria, all bores require a construction permit and a separate extraction li cence. ln South Australia, a construction permit is necessary for all bores, but a separate extraction licence is on ly required if the bore lies within a proclaimed area . The decision separately to control the use of a bore reflects a conclusion that the act of sinking or altering a bore has its own identifiable risks and consequences, which are different in character and kind from the possible consequences of using a bore, whether for investigation, extraction , drainage or waste-d isposal. Equally, the technology of sinking a bore is separate from that related to its use. Finally, to

approve construction is to regulate a finite Act; whereas the regulation of use is a continuing process, calling for different powers and mec han isms . and different sanctions. There are ~us technical and administrative reasons to support a division between construction and extract ion permits: although it seems that bureaucratic factors have also strongly influenced the outcome in some cases.

2.2.3

Controls over drillers

As previously mentioned, the original purpose of groundwater leg islation was to control the way in which artesian bores were sunk and. through a system of construction licences , to limit the harmful effects of improper bore construction . lt is apparent, however, that the mere act of specifying the way in which an act is to be executed cannot, of itself. ensure that it is done properly, and that penal sanctions may punish but not avert acts or omissions caused by ignorance of inadvertence. lt is thus the inherent inability of a conditional licensing syste m to ensure that bores are, in fact, properly constructed, which ultim ately leads to the policy of placing separate controls on those who are all owed to carry out the work authorised by a construction licence.

Although the need to control construction was early recognised, no moves were made to restrict those who might carry out drilling operations until the I 960's. One reason for this delay was doubtless that intervention to regulate activities by administrative control was much less com mon in the earlier part of the century, but this basic reason may have been reinforced by additional factors . While some limited in terference with the common law rights of a landowner to use his land as he pleased, including his right to win and use groundwater, might be tolerab le. it was probably not politically defensible to limit his own right to undertak e such work as he pleased on his own land by his own labour , and equally intolerable to restrict his power to engage such labour as he pleased to carry out work on his own land. The other side of the coin is that a system of licensing drillers amounts to a restriction on the right to work, and an individual's freedom to pursue such avenu es of economic gain as he may choose. Firmly held views on both these matters wou ld have made it politically difficult to introduce a syste m of licensing drillers at the same time that construction permits were introduced.

Continued on page 26

WATER QUALITY MANAGEMENT IN ARID AND SEMI-ARID ENVIRONMENTS Barry T. Hart ABSTRACT Water in arid and semi-arid regions is a very scarce resource and special care is needed to protect its quality. This paper considers the fundamentals in formulating a water quality management strategy , and highlights some of the problem s associated with the management of water quality in arid and semi-arid regions.

•

• the addition of effluents to streams during periods when there is either no flow or very low flow; • the protection of ground water quality; • the increase in stream salinity due to changing land use patterns or other influences .

FUNDAMENTALS OF WATER QUALITY MANAGEMENT

INTRODUCTION

Management Strategy

The development of effective management strategies is essential if stream water quality is to be adequately protected. In the development of such strategies it is not sufficient to concentrate only upon the water body itself; the close link between the stream and its catchment must also be recogni sed. A great number of the activities occurring within the catchment can eventually affect the stream itself.

This paper, outlines the fundamentals in volved in formulating a water quality management strategy, and considers three of the special problems associated with managing water quality in arid and semiarid areas of Australia, viz.

The primary purpose of any water quality management program is to maintain, and perhaps enhance, the water qual ity such that none of the designated water uses are adversely affected in the short or long term. To achieve this aim, the formulation of a suitable water quality management strategy needs to be separated into a number of stages.

T hese are shown in Figure I. lt is acknowledged that many of the fundamentals noted here as relating to water quality management apply equally well to all aspects of resource management.

Briefly, the development of a water quality management strategy involves five major steps : i) Assembly of detailed knowledge of the system (stream + catchment + ground water) to be managed, including the physical, chemical and biological characteristics, present and proposed land use in the catchment, present and proposed waste inputs .

The system must be considered in the widest sense to include the total catchment and not just the river section or lake in question.

Dr. Barry T. Harl is Head, Chemistry Deparlment and Water Studies Centre, Caulfield Institute of Technology, Victoria. This paper is based on a presentation made at an International Conference on "Hydraulic Resources of Arid and Semi-Arid Regions",held in Recife, Brazil, 17th-21st March, 1980.

WATER

13

Identify major

Identify environmental units and record significant figures

beneficial uses with in each envi ronmental un it

Identify the possible impacts of the development on the

Identi fy present and proposed inputs to each unit

water qual ity in each unit

Baseline survey -

identify physico-chemical

Exi sting water quality criteri a

and biological characteristics of each unit

Formulate water quality objectives to protect the benefical uses

Existing water

quali ty standards

In formation from further laboratory work to determine quantitative effect

levels

Formulate management plan

(include effluent policy and land use policy)

Further survey and monitoring work to determine modifications to existing water quality objectives

Figure I. Formulation of a water quality management strategy .

Frequently, insufficient time and money is allocated to obtaining the essential background information to the sys tem.

Also, if the planning and implementation of an environmental survey are poorly done, the in formation forthcoming will be inadequate. The principles involved in plann ing and implementing environmental surveys have been discussed by Hart (1980a), and are: • survey design - in which a "problem-oriented" approach and the use of conceptual models was advocated and stress placed upon the need for very carefully defined and realistic st udy objectives, the best system indicators and the methods to be used in assessing the da ta before the study commences.

• data collection - the need was stressed for a management team to consider the emerging data at regular intervals and, if necessary, to make changes to the project direction.

• data assessment - an activity is made all th e easier if the methods to be used in assessment of the data are considered in the survey design. ii) The determination of the beneficial uses of the water body to be protected. Most water bodies have multiple uses including one or more of domestic supply, agricultu re, irrigation , industry , recreation and the preservation of aquatic ecosystems.

Beneficial uses are hierarchi cal in that protection of some uses will also ensure the protection of others. For example, in order to protect lakes for passive recreational and aesthetic enjoyment, it is necessary to protect the water quality, at least to some degree, for foreshore and wild life preservation, for scientific and educational use and for maintenance and preservation of the aquatic ecosystem . The role of the public in th e task of identifying beneficial uses should not be overlooked. iii) Establishment of the best indicators to ensure that the identified beneficial uses are in fac t protected. As far as possible, these system indicators should be capable of quantitat ive measurement.

Ideally these sets of indicators would relate specifically to the system in question and would include physical, chemical and biological as pects. This ideal is seldom achieva ble; however, there art available several compilations of information on the possible sources, fate and effects of pollutants added to aquatic environments . Such data are known as water quality criteria (Hart, 1974; E nvironment Canada, 1979), and are collections of 14

scientific information relating the exposure to a pollutant and the risk or ma gni tude of effects. Water quality criteria then are scientific information on which a decision or judgement may be based as to the suitability of water quality to support a designated use. They can be either qualitative or quantitative.

While it is clear that certai n criteria, e.g. those rel ating to drinking waters, can be used with minor modifications in a ll parts of the world, this is not the case for criteria such as those relating to the preservation of aquatic ecosystems (Hart, 1980 b). Most of the water quality criteria in present day use are based on data relating to Northern Hemisphere systems, and must be used with some caution in Southern Hemisphere environments.

In Australia we are still in the v~y early stages of developing appropriate indicator species to test the potential biologica l impact of various pollutants (Williams, 1976; Mills et al., 1979). iv) The fo rmulation of management strategies, with emphas is on the development of policies for controlling effluent discharges and land use changes , such that water quality will be protected. such strategies should be flexible enough to permit any modifi cations shown to be desirable, e.g. rapid application of the results of a monitoring program.

Experience in a number of countri es has show n th at it is not • sufficient to defin e water qualit y objectives for identified beneficial uses and to use these to develop so-ca lled receiving water quality standards . Furthermore, it is necessary that an overall water quality management strategy be form ulated, to ensure that adequate controls are placed on the sources of potential po llu tants. This involves two aspects : th e development of poli cies for li censin g of all waste di sc harges a nd relating to a ll land use practices that could add to the overa ll waste load enteri ng the water body. The first is now common practice in Austra li a, but, beca use of the number of Aut horities with part ial pla nning responsibilit y, it is often difficult to ensure that water qua li ty implications of a ll planning a nd developm ent activites within a catchment are adequ ately consid ered. v) The development and implementation of a n adequate monitoring program to measure the success or otherwise of the management strategies. Clearl y, if this is to occur one must ensure that the best water qualit y ind icators are measured, and that th e WATER

sampling frequency and distribution is sufficient to detect any short or long term changes in quality.

Monitoring programs are of little value unless there also exists a mecha ni sm whereby any changes made obvious by the monitoring data can be decided upon and implemented. One way in which authorities can be kept "hones t" is by making . monitoring data freely available to interested members of the public.

Effluent Disposal

In arid or semi -arid areas it is common for stream flows at certain times of the year to be either extremely sluggis h or non-existent. In fact, in a number of streams in rura l parts of Victoria in summer, the stream flow consists almost entirely of sewage effluent discharged from a township.

The discharge of effluents, particularly those high in BOD, nutrients or toxicants, into slow moving streams, can have a number of consequences which may not be apparent at times of higher stream flow, including: • dissolved oxygen sag over considerable distances; • anoxic conditions in bottom waters of the deeper pools found in most streams; • increase in alga l growth in certain parts of the stream where the water moves very slowly; • increased macrophyte growth along the banks; • accumulation of toxicants in deeper pools.

In many parts of Australia, streams may dry up to form a series of isolated waterholes. Effluents discharged to the creek just prior to cessation of flow wi ll be trapped in the water hole and contribute to a significantly reduced water quality. Since these water holes often provide an essential habitat for the ecosystem survival such as fish breeding stock, any deterioration in water quality can prove disastro us.

The use of wastewaters to maintain stream flow may be extremely beneficial , and has been suggested in a recent report to the Australian Government (G.H.&D., 1978) as one of a number of potential re-use options for sewage effluents. However, if wastewaters are to be discharged in periods of low flow, it is essential that the quality be such that deterioration of the water qualit y does not occur . It is rare that the quality of effl uent is adeq uate to permit discharge at low flows without caus in g considerable qualit y dete ri oration .

During dry periods effective use can be made of effluents . In Australia there are many examples where adequately treated effluents have been used for ir rigation of sports field s, public lawns and crops such as lucerne. T he re-use of wastewaters in this way can have an important influence on the total water resource usage in an area by reducing the usage of first quality water for these purposes.

Groundwater

In arid and semi-arid regions gro undwater often provides an extremely important water resource . In many parts of Australia such are virtuall y the only source of water for stock (sheep and cattle). Additionally in many arid and semi -arid areas, gro undwater inflows may represent a considerable proportion of the flow in creeks and streams.

Obviously then, there is a need for special care in ensuring that land based activities do not cause deterioration of the groundwater quality.

Activities that may necessitate prohibition or particularly close control include: • land irrigation using wastewaters from domestic sewage plants, dairies, butter factories, food processing plants and other factories.

• land disposal of sl udges.

• land di sposal of urban wastes into " tip " sites.

• land disposal of industrial wastes.

• deep well injection of industrial effluents.

Activities contributing to an increase in so il or groundwater salinity should also be controlled as covered in more detail in the next section .

Two ot her points should be made regard in g gro undwat er quality.

Firs tly, because of the generally slow rate of travel of most ground waters, serious deterioration in water q uality may on ly become apparent at some considerable time in the future, perhaps as great as hundred s of years. Secondly, the difficulties and high costs of monitorin g groundwater quality shou ld be recogn ised.

WATER

Salinity

Long term increases in salin ity are occurring in an increasing number of Australian streams. The consequent decrease in quality can seriously affect the use of the water for domestic supplies, irrigation and stock watering. These salinity increases appear to result from two factors: • specific forms of land use, such as irrigation; • fundamental ecological modification, such as the replacement of native forests with shallow rooted perennial or annu al pastures for grazing purposes.

The first of these is well illustrated by the current situat ion in the River Murray valley, the largest area in A ustralia affected by salinity.

Salinity in the River Murray progressively increases from around 30 mg/L (TDS) in the upper reac hes to around 300 mg/ L at Merbein.

The salinity at Merbein varies considerably and, over the past 6 years (1974- 1979), has ranged between 100 and 500 mg / L (Graham , 1979).

Horticulturalists in the Mallee Zone (near Merbein) have experienced problems from irrigation with river water during grolonged periods of high sal inity. Stone fruit and citrus trees are mos affected .

A major proportion of the sa linity increase in the River Murray occurs in the Riverine Plains Zone, where irrigation has resulted in considerable rises in the water table levels, in some areas to within I m or less of surface. In some regions the gro und waters are quite saline ( 20 000 mg/ L). This rise in the water tab le has resulted in considerable loss of production (pastures, horticultural crops) through water-logging of soils and increasing salinity in the root zone, and in addition is contribu ting considerab le loads of sa lt to tributar y streams and eventually to the River Murray.

Estimates have been made of the relative causes of the increased salinity between the upper reaches and the Mallee Zone (G.H.&D., I 970). These are: Concentration by evaporation IO OJo Salt inflows - tributaries 30% Drainage discharges from irrigation areas 20% Groundwater inflows 40% The other factor referred to as contributing to increased stream salini ty, that of ecological modifications, has resulted in major problems in both Victoria (Jenk ins, I 979) and Western Australia (Peck, 1978).

The transition from deep rooted, natural evergreen forests (roots to 20 m) to shallow rooted, peren nial and a nnu al pastures (roots to I -2m) has been shown to have very major effects on the lo cal water balance (Peck and Hurle, I 973). Since there is' considerably less evapotranspiration from the pastures, more of the total rainfall which penetrates the soil will be added to the groundwater. The groundwater table ri ses a nd increased hydra ulic pressure head may force this water to the soi l surface at low points, or into th! st reams of the catchment .

These gro undwaters often conta in high levels of dissolved salts and may result in salini sat ion of areas of surface so ils and increases in stream sa linit y. T he effects on the land are referred to as dryland salting. The estimated extent of the areas affected are: Victoria 85 000 ha (Jenkin, I 979).

South Australia 14 000 ha (Matheson , 1968).

Western Australi a 167 000 ha (Malcolm and Stoneman , 1976) .

The areas affected in other States, are not known.

In South Western A ustralia the largest river, the Blackwood, has shown a three-fold in crease in sa linit y from the 1910s to the 1960s (Peck et al., 1973) mainly du e to the widesp read change in land use from forests to grazing . A su rvey of river qua lities has shown that over one third of the annual discharge had TDS in excess of 1000 mg/ L and a furth er one third of the flow had TDS in the range 500- 1000 mg/ L. In We stern Victoria, the stream sa lini ties now ra nge from around 60 mg/ L to more than 3000 mg/ L with mean values around 1350 mg/ L (Graham , 1979).

>

REFERENCES ENV IRO NMENT CA ADA . ( 1979). Guidelines for Surface Wa1er Quali1y, Inl and Wa1ers Directorate, Wa1er Quali1 y Branc h , Environm enl Canada , O!lawa.

G. H .&D. ( 1970). Murra y Valley Salini1 y l nves1iga1ion, Guueridge Hask ins and Davey , Melbourne.

Continued on page 26 15

WATER RESOURCE ALLOCATION

BY LAND USE CONTROL M. R. Till SUMMARY

At Padthaway, in South Australia, groundwater from a n unconfined aquifer is used for the irrigat ion of lucerne, pastures, field crops, vines and vegetables. The soils are so permeable that a large proportion of the water app lied by flood irrigat ion percolates back to the aquifer; large suppli es of water are obtained and deep rooted crops may draw directly on the watertab le. Under these conditions control of the water resource by regulation s based on volumetric measure would be in appropri ate, and instead the nett amo unt of water actually used by a crop cou ld better provide a basis to determine water allocation s. A system was devi sed whereby landhold ers were involved in es timating the relative evapo-t ran spiration rates of different crops.

These estimates were incorporated into a method of control by land use which enabled a landholder 's "water quota " to be specified and thereby transferred, divided or changed from one crop to a nother, for instance from lucerne or pasture to sunflowers, vines or vegetables .

The acceptance of this system by ti)e community has probably been aided by the irrigators being involved in development of the techn ique. This paper describes a method of water allocation which can be used where the volum etric measurement system is inappropriate. The approach allows water allocations to be reduced , changed from one crop to another, and to be split or transferred upon sale of a property.

--- -

10

0

SCALE O F KILOMETRES

THE PROBLEM

As shown in Figure I, the Padthaway Irrigation Area li es midway between Keith and Naracoorte . The average an nua l rainfa ll is 530 mm and the average annual evaporation 1520 mm . The irrigation area lies on a gently sloping plain and on the frontal escarpment of a sand range which rises 100 metres a bove the plain. The area irrigated is about 3 000 ha, distributed over 35 sq km elongated in a northerly direction over a distance of 35 km a long the escarpment. The ranges have a sandy topsoi l, usually one metre deep, becoming shallower along the top of the frontal slope. Soils of the plains are sands to sandy loams over well-structured clays immediately at the foot of,the range, tending to more impermeable clays further out across the plain.

The so ils are highly permeable so there is virtually no surface run-off and excess rainfall and irrigation water infiltrates vertically. The water resource exploited by irrigation is the watertable aquifer which, on the plain, is so close to th e surface that water can be pumped using centrifugal pumps mounted at the surface or in a shallow pit. In vestigations show that the water source is a small amount of stream discharge (3 OJo ), underground flow through the sand range (25 OJo) and rainfall (72%) (Gerney et al. 1975).

The region is used for grazing beef cattle and sheep for meat and wool production together with a small a mount of cereal growi ng.

Pastures and crops are also grown for seed production. Irrigation was imposed on an existing extensive land use. At Padthaway it began about 1956 and by 1965 was well estab lished. Initial development was by flood irrigation of pastures and lucerne using high capacity centrifugal pumps to draw water from the shallow water table. Subsequently, vegetables and vineyards were grown and irrigated by sprinkler or drip m_e thods as well as by flooding. Irrigat ion of the frontal slope of the sandy range commenced during this second phase. These enterprises , involvin g new crops and soils, were usually by new landholders. The areas and types of crops have changed continua ll y as landhold ers react to changing economic conditions (see Table !), After the 1967 drought, landholders expressed fears abo ut the long term yield of the groundwater basin because of apparently declining water levels . Investigat ions bega n in I 970 to determine the characteristics of the water reso urce, its rate of exploitation and the options

Max Till is Principal Soils Officer (Irrigation), Department of Agriculture, Adelaide, South Australia.

16

SOUTH

AUSTRALIA

#

PADTHAWAY AREA - LOCAT ION MAP

------

FIGURE 1

available for manage ment. First repo rts by Harris (197 1) showed that usage of the water resource was 80 per cent of the intake. Further investigation by Gerny et al. (I 975) confirmed this situation and indicated further that intensive irrigation was permissible on a long term basis only on a strictly limited scale.

When management of the water resource in the Padthaway Irrigation Area was considered necessary, water allocation by measure was considered but was di scarded beca use: TABLE I: AREAS OF CROPS: PADTHAWAY IRRIGATIO N AREA CROP Lucerne Pasture Seed crops Sunflower Sorghum Maize Vegetables Vines Total

1972-73 (ha)

1975-76 (ha)

I 437

429 140 435 558 0 96 177 600 2497

601 476 17 1 36 18 16 538 3293

WATER

1

the expense of metering large capacity pumps was co nsiderable and moreover these pumps were often relo cated during the irrigation season; the return fl ow to the watert ab le of irri gat ion water not used by plants co uld not be metered; the deep rooted crops of vines and lu cerne wou ld ha ve roots reaching the watertab le. The water use by these crops co uld not be metered.

The prob lem therefore was to devise a syste m of water allocation which did not use contro l of water by measure a nd which would allow for the transfer of water a llocations within a holding or upon sale of a property and for a chan ge in land use from pasture or lu cerne to vineyards, vegetables and sunflowers. To be effecti ve any method of a ll otment wou ld require the endorseme nt a nd co-o perat ion of th e com munity . For th is reaso n it seemed d es irable that the communit y should be involved in its development a nd imp lement a tion .

WATER ALLOCATION BY LAND USE CO TROL The ex tra water used by an irri gated crop is th e difference between it s actual evapo-t ra nspiration and th e contribution from rainfall. The relative use of the water resource by various cro ps is expressed by the ratios of these differences . These ratios therefo re express the areas of the different crops having the same gross water u se . This gives a basis for determining equ ivalent areas in terms of gross evapo-tran spiration independ ent of the qua ntities of water pumped and a pplied. Lucerne was chosen as a sta nd ard crop for three reas ons : when co ntrols were imposed it occupied the greatest fra ction of th e irrigated area, its a nnua l evapo-transp iration per unit area was li kely to be th e greatest of any crop, a nd because most changes in crop type were ex pected to be from lucerne to som e other crop.

One of the simplifica tions adopted was to ignore the effects of the method of m a nagem ent o r utilizati o n of th e lu ce rn e crop on its a nnual evapo -transpiratio n . The evapo-t ra nspiration of the la nd use sys tem for the whole year was considered even though this was artificial and arbitrary in the case of vegetables, which are only grown for part of the yea r . Using thi s co ncept of the a rea of a cro p which has the same gross withdrawal of water from the water resource as a unit area of lucerne, calcu lations of the ratios or " lucerne equivalents", as they were called , could be m ade for eac h crop .

As a n example, the calculation of a lucerne equi va len t for vineyards is as fo llows : Lucerne Vineya rds A nnua l evapo-transpiration (mm) 1 100 780 A nnual rainfall (mm) 532 532 Withdrawal from water reso urce (mm) 568 248 Lucerne equivalent fo r vineyards 568/248 = 2.3, i. e. 2.3 ha of vineyards with draw the same gross amo unt of water from the water resource as 1.0 ha of lucerne.

Lucerne equivalents for other crops were calculated to be: Ir rigated seed crops 3.2 Summer fodd er crops I. 9 Potatoes 2.5 Onions 2. 7 Spr ing irrigated past ure 1.9 1.9 S unflowers The water a llocation to a la ndhold er was calculated in th e following way . T he areas of a mixture of crops was expressed as a si ngle figure of hectares of lu cern e equi valents . Reduct io ns in a llocations were m ade as a perce ntage of th is figure, thus a ll owi ng the landholder to reduce the area o f whichever crop he chose. If an a llocat ion was split upon the sale of a property, the total lucerne equivalent was divided accord in gly and if a landholder wished to change his mixture of crops, this was possible provided he did not exceed his tota l lucerne eq ui vale nt. The system requ ires monitoring of the irrigated areas which is done by ae rial photograp hy a nd property inspection s rather than by a ny techniques of wa ter m eas urement.

COMMUNITY INVOLVEMENT IN WATER RESOURCE MANAGEMENT The Undergro und Waters Preservation Act 1969-1975 and subsequently the Water Resources Act 1976- 1979, enacted by th e Govern ment of So uth Austral ia, provid e a forma l structure for th e j oint in volvement in water resource m a nagement by members of the com -

TABLE 2. CROP CALENDAR FOR SUNFLOWERS AT PADTHAWAY, SOUTH AUSTRALIA, AND IMPLIED "CROP FACTORS " MONTH

C ROP OR SO IL CON DITIONS RE LATEJt CROP FACTOR TO WATER LOSS " f"

Jan

85 per cent grou nd cover, crop I met re high start ing to flower, irrigations every 2-3 weeks.

0. 7

Feb

Irrigations continue, maximum growth period, leaves are green and in fu ll flower.

0. 7

Ma r

Irrigations continue - 5 for season. Crop now d ryi ng off a nd leaves dropping - crop finish by end of mo nt h .

Reaping Apri l-May, crop t hen dry brown sta lks.

0.5

May

As for Apri l, green cover if not sprayed wit h herbicide .

0 .5

Jun

Green growi ng grass o r wet soil.

0. 7

Jul

As for Ju ne.

As for June.

0. 7 O. 7

Ap r

Aug

0.4

Sep

First ploughing bare.

ground not yet completely

0.3

Oct

Ground bare a nd drying, cu lti vatio ns continue.

0 .3

Nov

Ground bare and dry, irrigat ion may be required crop sown mid- late November.

0 .2

Dec

Crop 30 cm high by end of month, irrigated o nce, no complete gro und cover b y end of month.

0.4

munity a nd Govern m ent employees. In the a dm inistration of these Acts, th e responsible Minister of the Crown m ay take the advice of a local Adv isory Committee set up under eith er Act and hi s d ecisions regardi ng the issue of a prescribed licence or the condition s attached to a li cence may be challenged by the la ndh older in an Appeals Tribunal. In the Padthaway Irrigation Area, which was proclaimed under t he latter Act as an Area where the Act app lies, both these opportunities for landholders to influence ¡ water management policies were taken .

In October 1973 t he Minister responsib le for t he admini stration of the Underground Water Preservat io n Act ann ou nced his intention to restrict underground water usage in the A rea to that u sed in the 1972/73 seas on and that this restriction would be implemented by con trolling the area of irrigated crops and that t he base would be those crops irrigated in th e 1972/7 3 seaso n . Necessary clianges to the Act delayed implementation until I Jul y, 1975. T he Water Reso urces Act replaced th e ex istin g Act on 1 Jul y, 1976, with similar provis ions for the con t ro l of water reso urces . U nder the new Act , the total water withdrawa l from Jul y 1st , 1976 for a periodtof 3 years, was reduced to 95 percent of the leve l of tota l usage in 1972/73 sea so n . These Minister ia l decisions were the kind of decision s where the advice of the Padthaway Water Reso urces Advisory Committee might be so ught.

In t he p roposa l for the use of lucerne equivalents to represent water use, th e local m emb ers on the Advisory Co mmittee played a more direct role. The mean a nnua l rain fa ll and evaporation and th e a nnua l evapo-transpiration of the cropp ing system were required. The meteorologica l data were available (Gerney et al. 197 5) but not th e annual evapo-transpiration. Estimates of this were mad e using the form ula: E, = fEP where E, is evapo-transpiration, EP is evaporation from a U.S. Weath er Bureau Cla ss A evaporimeter and " f " is the ratio of E/Ep called the "crop factor" which varies from month to month. The a nnua l evapo-tra nspiration is the sum of the monthly estimates .

Comm unity involvem ent was obtained th rough a meeting of a selection of farmers from Padthaway, each with expertise in a particular crop. The method of lucerne equiva lents was explained and the use of "crop factors" to es timate evapo-transpiration. The group was given the tas k of describin g t he stage of growth of th e crop or sta te of soil preparation for eac h month . Officers of th e Departm ent of Agri culture set crop factors for we ll watered lucerne at 0. 7 and bare ground at 0. 1 and tak ing into account the growers' knowledge of their crops, crop factors we re set for each crop for eac h month. Th e lucerne equi va le nt s for eac h c rop were th e n calcu lated a nd a noma li es ironed o ut. A n exa mple of the informa ti o n for sunflo wers in shown in Table 2.

Continued on page 26

17

ACTIVATED SLUDGE TREATMENT SUBIACO W. AUSTRALIA DEVELOPING OPERATING PROCEDURES Allen J. Gale INTRODUCTION Adequately controlled operation of a wastewater treatment plant is most critic al if the design effluent quality is to be maintained and nuisance to the public avoided. It is wasteful of public funds to expend large sums construct ing a technically well-designed plant and to then fail to appreciate the significance of correct operating procedures.

This paper outlines the experience of Camp Scott Furphy (CSF), Consulting Engineers at the Subiaco Wastewater Treatment Plant (WWTP) in Perth where CSF was responsible for operation of the installation as a demonstrtion plant for seven months and for analysis of operat in g results for a further five months. CSF was commissioned to undertake these duties by the Perth Metropolitan Water Supply, Sewerage and Drainage Board (MWB) as an adjunct to a main study of upgrading measures for the plant.

For the purpose of the study modifications were made to the existing installation as described herein and the modified plant is termed the 'demonstration plant' .

REASONS FOR INVESTIGATIONS The major reason for operating the demonstration plant, and in fact for undertaking the main study, was the public outcry over several years against odours generated at the Subiaco WWTP. The odours were most significant during the summer months although complaints were received throughout the year. The problem existed over a wide area, with comp laints received from locations as far as five to six kilometres from the p Ian t .

Initia l in vestigatio ns showed that if the raw wastes were chlorin ated, odours from the influent and primaries co uld be contro ll ed .

It appeared that the secondary treatment processes were re sponsible for the most objectionable odours, and a demon stration plant was decided upon with particular attention to the secondary treatment.

The seco ndary faci li ties were operated as a Modified High Rate System with solids retention times (SRT's) in the order of I to I ½ days, and mixed liquor suspended solids (MLSS) concentration s in the order of 400-500 mg / L. There was some concern that the wastes may not be suitable for biological treatment, so it was necessary to establish that the activated sludge process could operate satisfactorily and to determine the most satisfactory operating range.

DESCRIPTION OF SUBIACO WWTP Treatment facilities at the Subiaco WWTP were conventional, as shown in Fig. 1. However, many of the facilities were outmoded, or deficient in mechanical details, and this had a detrimental effect on operation and treatment efficiency. Modification to some facilities was required prior to commencement of demonstration plant operation.

The plant incorporated pre-chlorination followed by grit removal, screening and primary settling. The primary effluent passed to four aeration tanks each of which was fitted with a coarse bubble diffused air aeration system of one form or another. Compressed air generated was insufficient to permit all the primary effluent to discharge to the secondary treatment facilities, and so a portion of the primary effluent was bypassed .

Primary effluent entered the aeration tanks at the head end of the tanks only, and discharged at the effluent end. The flow pattern was plug flow through the long, narrow tanks (length to width ratio of 15:1).

Mixed liquor from the aeration tanks flowed to six circular secondary clarifiers . Several design features of these clarifiers were inadequate,

Allen J. Gale is an Associate of Consulting Engineers Camp Scott Furfly Pty. Ltd. in the Company's Perth Office.

18

INFLUENT

GRIT

TO ON SffE OSPOSAL

]

DIS INTEGRATOR

SLUDGE PUMPING STATION SUPERNATANT

PRIMARY ANAEROBIC DIGESTERS

RETURN & WASTE SLUDGE PUMPING STATION

FLOW MEASURING FLUME

IFFLUENT

•

TO SEA

SUBIACO WWT. P. SCHEMATIC

Figure I. Subiaco Wastewater Treatment Plant -

schematic.

causing malfunction of the solids/ liquid separation phase of the activated slud ge process. This contributed to failure of the process at times, with consequent odour generation for extended periods.

Because of the limited oxygen supply , the quantity of primary effl uent receiving secondary treatment was affected considerably by the organ ic loads in the primary influent. If the organic loads were excessive, dissolved oxygen (DO) in the aeration tanks was depleted, resulting in anaerobic conditions in these tanks and consequent odour generation. Dissolved oxygen profiles taken during periods of peak loading, prior to commencement of the demonstration plant revealed that a considerable portion of the aeration tank s was deficient in DO and that there was a large variation of DO concentration with depth .

The limited air supply placed a severe restriction on operation of the demonstration plant.

Prior to commencing the demonstration plant, three temporary modifications were made to the secondary clarifiers to achieve a satisfactory activated slud ge system. First the inlet wells were modified to minimise short-circuiting of the mixed liquor discharged into the tanks (in the original system much of the incoming mixed liquor was WATER

drawn directly back to the return sludge line) second, a positive sludge scraping system rep laced th e ex isting cha in scraper mechanisms.

The tank fl oor had been graded steeply with the intention that the chain wou ld force the settled slud ge down the slope into the withdrawal hopper. However, this did not eventuate, and banks of anaerobic sludge acc umulated. Occasionally the sludge sloughed off and was returned to the aeration tanks as a thick anaerobic mass or rose to the surface to form malodorous floating mats. The temporary plough scraper proved to be an effective although not completely satisfactory slud ge removal system. And third , the speed of rotation of the scrapers was increased from about 0.9 m/ sec to 2.5 m/ sec to reduce the holding time of the slud ge in the clarifiers and minimise the potential for development of anaerob ic conditions.

OPERATION OF THE DEMONSTRATION PLANT The demonstrating plant operation commenced 16th March , 1979 and ended 7th September, 1979 (25 weeks). The operations and analysis period continued until 29th February, 1980. During these periods the secondary facilities were operated over a range of SRT's between 0 .85 days and 5.7 days, and with MLSS concentrations ranging between about 900 mg/Land 3,000 mg/ L. PROCEDURES FOR CONTROL OF ACTIVATED SLUDGE OPERATIONS Mode of Operation The desired operating range of the activated sludge process was controlled by maintaining a required SRT rather than Food-micro orga nism {F / M) ratio. The SRT was a much more meaningful relationship and could be directly related to daily operations . It necessitated analysis for MLSS and RAS concentrations only. Once these were known , the mass of slud ge to be wasted for maintenance of any SRT could be determined. The F/ M ratio is a somewhat impractical method for control as the F (or the BOD load to the aeration system) cannot be determined for five days.

Once a required MLSS concentration had been attained the general proced ure was to maintain a specified wasting rate for several days . If the MLSS varied outside the required range, the time of wasting was varied for a day or two to adj ust the MLSS concentration . This method was preferred to adjusting the wasting time on a daily basis as the process was not sufficiently sensitive to the variations required.

Dissolved Oxygen Control DO control was achieved by varying primary effluent flow rather than the normal operation of adj usting air input. Air flow was maintained essentially constant and organic loads varied to maintain a DO in the order of 1 mg / L at the inlet end of the aeration tanks. This method of control was possible only because a portion of primary effluent was bypassing the second ary system at all times .

Although variation of primary effluent inflow was an inefficient method of DO control (since it was impractical to vary the flow to match variations in organic loads), it was better than varying the air flow beca use of severe limitations on blower capacities and the lack of faci lities for convenient adjustment of air inputs.

Return Sludge Settled mixed liq uor was returned from the secondary clarifiers at an esse ntially constant rate for each operating mode, to maintain a particul ar MLSS concentration. No attempt was mad e to vary the return rate diurnally to match variations of organic loads to the secondary fac ilities.

Beca use of the limitations of the temporary sludge scraping system high return ratios were empl oyed to aid transport of settled sludge to the withdrawal hopper (ratios were generally in the range 1.1 to 1.9).

Form ation of a slud ge blanket in the clarifiers was not possible at these high return ratios.

Sludge Wastlng Sludge was wasted from secondary clarifiers to maintain the desired SRT's. Beca use of the high capacity of the waste activated sludge (WAS) pumps in relation to the flows and loads to the aeration facilities , wasting was on ly required for a short period each day (varying between one and six hours per day). The shorter wasting times were carried out in one operation, the longer in two operations.

WATER

Control Charts and Tables For the known limits of the system , it was possible to develop a series of ch arts and tables which enabled variations nec~sary to any portion of the process to be determined quite rapidly rather than to make calc ul ations each for each variation.

Charts were developed for: • the relationship between MLSS concentration, SRT (or conversely F/ M ratio) and the mass of BODs to be added per aeration tank.

• oxygen requirements (and thus air requirements for a known diffuser transfer efficiency) for different SRT's and mass of BODs to each aeration tank . From this a relationship between SRT and maximum mass of BOD 5 to be added to aeration, based on the. maximum amount of air available, was developed . RAS • the relationship between the return sludge·ratio and the - - - ratio .

MLSS . . an SRT ",or a part1cu . 1ar MLSS RAS rat10. . . ttme .

• wastmg to mamtam • wasting time to adjust the MLSS concentration.

These charts were simple to interpret and using them, highly trained personnel were not required to determine operating requirements for the second ary faci lities. Development of simil ar charts for any activated sl ud ge system would be of great assistance to any operator.

Analyses Made Sampling and analysis was carried out by MWB personnel at the Subiaco WWTP laboratory, seven days per week, and included the following: MEASUREMENT

FREQUENCY

{I) RAW WASTEWATER

• • • • •

BOD 5 - total and soluble CO D - total TOC - total TSS pH

(2) PRIMARY EFFLUENT & SECOND EFFLUENT • BOD 5 - total & soluble • COD - total • TOC - total • TSS • pH • Amonia-Nitrogen (N HrN) • Nit rate-Nitrogen (NOrN) • Nitrite-Nitrogen (NO 2-N) • Alkalinit y, as CaCO3

(mg/ L) (mg/ L) (mg/ L) (mg/ L) (no units)

Daily bulked sample

Daily bu lked sample (mg/ L) (mg/ L) (mg/ L) (mg/ L) (no units) (mg/ L) (mg/ L) (mg/ L) (mg/ L)

.,

(3) MIXED LIQUOR • M LSS at effluent end of each aeration tank & of comb ined mixed li quor

(mg/ L)

Twice daily grab sample

• Initial sett ling velocity (ISV) of combined

(m/ hr)

Daily grab sample

• Sludge volume index (SV l) of combined

(m l/ g)

• Volatile solids in combi ned

("lo)

Twice daily grab sample Intermittent grab sample

• DO 's & temperature at inlet end, I / 4, I / 2, 3/ 4 and effluent end of aerat ion tanks • pH at effluent end of each aeration tank and of combined mixed liquor

(mg/ L, 0 C}

(no units)

Twice daily in aeration tan ks

Twice daily grab sample Twice daily grab sample

• Microscopic examination

(- )

• Oxygen uptake rate at inlet end, l /2 point and effluent end of acration tank

(mg/ L/ hr)

Week ly grab sample

(mg/ L)

Twice daily grab sample Twice da ily grab sample

(4) RETURN ACT/VA TED SLUDGE • TSS

• pH

(no units)

19

RESULTS OBTAINED: WASTE CHARACTERISTICS

BODs and TSS Concentrations Both BOD 5 and TSS in the raw wastewater were extremely variable with a range of 240 to 650 mg/L forBOD s and 205 to 510 mg/ L for TSS over the period June 1978 to February 1980. The high BOD s value reflects the effect of industrial discharges on plant inflow - the major industries are-food related and discharge wastes high in soluble BOD 5 Improvement in effluent quality was achieved after making temporary modifications to the plant and amendments to operating procedures. Secondary effluent BODs decreased from an average 70 mg/ L for the period September 1978 to February 1979, to 22 mg/L for the eq uivalent period in 1979/ 80 . Similarly secondary effluent TSS decreased from 76 mg/ L to 28 mg/ I. Relationships Between Organic Parameters Although BOD 5 is the bes t es ta blished a nd most com m onl y used organic parameter for design and operation of a secondary biological treatment process, it is inconvenient because of the time factor and possible inaccuracy . On the other hand , the COD and TOC tests can be comp leted in a maximum of fo ur hours and are less susceptible to inaccuracy.

The results for COD and TOC should be considered as an independent measurement of organic matter, rather than a substitute for the BOD 5 test. T heoret ically, there is no definable rela tionship between these parameters, but for a particular waste it may be possible to develop approximate relationships which could then be used to determine an approxi mate BOD 5 load, in shorter time. Relationships oetween the organic parameters vary from plant to plant, and the variation may be quite significa nt , depending on the extent and constituents of the industrial waste fraction.

Straight line relationships between COD/ BOD and TOC/BOD were developed for Subiaco WWTP raw wastes, but correlations were poor and reliable relationships could not be developed. The poor corre lations were indicative of th e extremely variable nature of the incoming wastes.

COD T he ratio BODs for the raw wastewater was in the order of 1.7 to 2.0 for BOD 's in the range 200 mg / L to 400 mg / L indicating that the wastes should be amenable to biological treatment.

IBtlmate BOD and BOD Reaction Rate The ultim ate BOD's and BOD reaction rate constants for the raw wastewater and primary effluent were determined on two occasions, resu Its are set out in Table 1.

TABLE I. ULTIMATE BOD & BOD REACTION RATE ULT IMATE CAR BO NACEOUS BOD (mg/ L)

Raw Primary Wastes Ef fluent •576 :573

545 470

• 14Feb 1979

BOD REACTION RATE CONST ANT k @ 20°C (to base 10) ( 10 days - 1)

80020 8005

Raw Wastes

Primary Effluenr

Raw Wastes

Primary Effluenr

0.444 0. 135

0. 131 0. 140

1.34 1.43

1.36 1.31

: 5 April I 979

T hese res ults indicate that the wastes are readily treatable using biological processes. The BOD reaction rate constants compare favourably with published data for essentially domestic wastewaterS', as do the relationships between BOD 20 and BOD 5. It was concluded that the industrial wastes di scharged to Subiaco WWTP did not adversely affect treatability by a biological process , providing allowances were made for the additional organic loads imposed.

RESULTS FOR SECONDARY FACILITIES

Results of analyses made during the demonstration plant are not reproduced here, as detailed investigation of these data is beyond the scope of this paper. However, there are some points which are worthy of note with regard to operations and comment follows .

Effects of Variable Atmospheric Conditions During the twelve month investigation period the plant was subject

20

to wide variations in clim atic conditions, the most significant being temperature. Variations of temperature affect the basic kinetics of the activated sludge process such as the rate at which the reactions occur, oxygen transfer efficiency and sludge production , together with settling properties of the mixed liquor. T heoretically, the specific carbonaceous BOD 5 reaction rate doubles for a 10°C increase in temperature and the nitrification rate doubles for a 6°C increase. Hence the retention time to attain a specified degree of treatment should be much less at elevated temperatures . For Subiaco WWTP, with wastewater temperatures up to 30°C, the potential effects of temperature were particularly significant. Qu antific ation of these effects is sometimes difficult but attempts were made wherever possible to allow for effects of temperature on the results obtained .

Mixed Liquor DO / Oxygen Consumption DO's varied considerably along the length of the tanks, which would be expected with a plug flow system, as the organic loads reduce with travel along the tank. Except for the initial few weeks of the program, DO at the inlet end of the aeration tanks was maintained at about 1.0 mg/L with the DO at the effl uent end in the order of 4.0 to 6.0 mg/ L. No control was possible over the high DO' s at the effluent end of the tanks if a satisfactory DO was to be maintained at the inlet end.

Satisfactory facilities for tapered aeration were not available.

Mixed liquor DO concentration significantly affects oxygen transfer to the wastes. Oxygen transfer efficiency is normally expressed as a percentage under standard conditions . These standard conditions are recognised as zero atmospheres pressure, 20°C temperature, and zero DO . Adjustments for conditions other than standard conditions are norm ally based on the fo llowing equ ation (using the gas/ liquid / film transfer theory):

1.024(T-20)

X

[ CST - CT ]

X

E20

(I)

C s20 0 2 transfer efficiency at temperature T a nd wastewater DO co ncentrat ion CT 0 2 transfer efficiency at 20°C, zero DO Sat ura tion DO co ncentration in wastewater at Temperature T (mg/ L) Actual DO concentration in wastewater at temperature T (mg/ L) Saturation DO concentration in wastewater at 20 °c Most references stress the importance of the effect 'of temperature on oxygen transfer efficiency, but little emph asis is given to the importance of the operating DO concentration.

From equation (1), the effects of temperature on oxygen transfer effi ciency are slight, as the first term oi the right hand sid e (an allowance for reduced kinematic viscosity with increased temperature) is almost completely offset by the second term on the right (an allowance for reduced driving force with increased temperature.)

However , the DO co ncentration in the wastewat er, CT, ha s a most significant effect on oxygen transfer efficiency and ac.counts for the variations in the quantity of oxygen actually dissolved into the wastewater between two d ays when , although all other conditions were equal, the DO concentration in the wastewater varied .

T he following example illustrates the above point:

Oxygen added to wastes Temperat ure T Sa tura ti o n DO at T(CsT) (for Beta = 0.90)

CASE I 10,000 kg/ d

CASE 2 10,000 kg/ d

30 °c

30°c

6.9 mg/ L

6.9 mg/ L

Satu ratio n DO at 20°C (C 520) DO at T(CT)

8.3 mg/ L

8.3 mg/ L

1.0 mg/ L

3.0 mg/ L

From eq uation (l) ET, CT

0.90 E20

0 .60 E20

T herefore , under the same conditions, the system with mixed liquor DO of 1.0 mg/L will transfer 50% more oxygen than the system with mixed liquor DO of 3.0 mg/L . Physically this means th at the higher the operating DO concentration the larger the oxygen generation facilities required , and the higher the operation costs for the same degree of treat ment.

WATER

Nitrification

For the purpose of th e Subiaco st udies, nitrification was defined as the ox idation of Ammoni a Nitrogen ( Hr N) to ei th er the itriteNitroge n (NOr N) or Nitrate-N itrogen (NO r N) form. Degree of nitrifica tion was meas ured as~ (NH 3 pri mary - NH3 seco ndar ylFor the extremely high wastewater temperatures experienced during summer (up to 30°C) nitrification may occur with SRT's as short as one day and therefore. although not req uired for effl uent quality, nitrification ca nn ot be prevented for a significan t period of the year.

Thus the effects of nitrification on the demonstration plant were given special consideration.

Durin g th e demo nstration plant operati ons a nd anl ys is phases, nitrification did occ ur , but 'complete' nitrifi cat ion (i.e. oxidation to the NO 3 - N form) was inhibited. Based on estab lished theory the NO 2 forming micro orga ni sms (Nitroso monas) ha ve a slower growth rate tha n the 0 3 form in g mi cro organisms (N itrobacter). Thus, if nitrification does occur then th e predominant ox idized fo rm should be NO 3 - N. The appa rent inhibition of Nitrobacter may have been due to excess ive fr ee amm onia or gree nitrous ac id , as reported by Anthoni se n el. al. a nd Won-Chon g & Loehr .

Nitrification significa ntly reduced the mixed liquor pH and alkalinity (primary effl uent alk alinity was in the order of 150 mg/L. As nitrification com menced pH dropped from in excess of 7 .0 to as low as 5.8. pH co rrection, by the additi on of sodium hydrox id e to primary efflu ent, was applied for six weeks without havin g any noticeable effect on the degree of nitrification.

Denitrification was definitely occurring although there was no evid ence of it occurring within the second ary clarifiers (e.g. rising slud ge in the clarifiers). From Fig. 2 it can be seen that as the degree of nitrification increased so did the degree of denitrification. The degree of denitrification was extremely high for times of high degrees of nitrification and in fact was as high as reported elsewhere in integrated nitrification / den itrification plants with an anoxic zone preceding the aeration basins. (Cooper el. al. 1977a and Cooper el. al. I 977b .) Data was insufficient to define where denitrification was occurring.

For the SRT's employed at Subiaco (up to 5.7 d ays), chlorin ation of the RA S was inhibitory to nitrification. The critical rate was somewhere between 10 mg/ L and 33 mg/ L. further study is necessary to better define th e critica l rate.

trations and ISV (and therefore surface loading rates) developed to aid satisfactory operation of second ary clarifiers .

At Subiaco. results obtained from the ISV tests indicated settling properties below those in the published literature, requiring larger than norm al secondary clarification facilities.

FOAM CONTROL WITHIN SECONDARY FACILITIES During the demonstration plant operation a significant foam problem developed within the secondary treatment system. Complete analysis of the problem is beyond the scope of this paper, but this general description is included .

The foam differed from the normal white sudsy detergent foam often encountered on aeration tanks. It was extremely dense, with a high solid s content. Defoaming oil, normally quite effective for control of the norm al light foam, was completely ineffective and water sprays only temporarily coll apsed the foam . If allowed to build up in the mixed liquor channels and clarifier inlet wells, the foam compacted and took on the appearance and texture of a scum, up to 150 mm thick .

The major effect of the foam was a significant increase in maintenance involved in its removal from the secondary clarifiers. The degree of treatment attained was not affected although effluent qu ality deteriorated due to scum carry-over.

Several samples of th e foam were analysed by the Western Australian Public Health Department, with particular attention to identification of the bacterium Actinomycetes Nocardia, species Amarae. In literature there are several references to this species causing nuisance problems in activated sludge plants throughout the world and to possible methods of controlling its formation . There is little knowledge however , of the reasons for its generation and methods of positive control. The Public Health Department did succeed in tentatively identifying Actinomycetes Nocardia but the species Amarae cou ld not be positively identified .

Further research is required on the formation and control of the foam . The most promising control method at Subiaco was chlorination, although further work is required to determine: the optimum dose rates both for removal of the foam and prevention of its re-formation. the best point of application . effects on activated sludge operations. positive identification of the constituents of the foam and conditions conducive and detrimental to its formation.

Secondary Clarifiers

Ana lysis of the ac tivated slud ge process is incomplete without consideration of the secondary clarifiers; they are an integral part of the process and it is not sufficient to attain a high stand ard of biological treatment without achieving satisfactory solids / liquid separation in the second ary cl arifiers.

In addition to solid s/ liquid separa tion the clarifiers must provide adequate thickening of the return sludge for maintenance of required MLSS concentrations in the aeration tanks. If adequate solids/ liquid separation and thickeni"ng are not attained , the MLSS concentrations will not be maintained and the activated sludge process will fail, resulting in poor quality effl uent.

Settling of mi xed liqu or follows hind ered settling theory which in effect means that if the hydraulic overflow rate from the clarifiers exceeds th e initial settling veloc ity (ISV), failure of the secondary clarification process will occur. ISV varies with SRT, temperature and MLSS concentrations , the most significant factor being MLSS (the hi gher the mi xed liquor concentration the lower the ISV and therefore the larger the clarification requirement .) Thus the ISV must be determined for a ra nge of MLSS concentrations.

Once a pattern is established , the ISV test can also be used as an indicator of poorly settling sludge developing within the system. ISV's can be determined quite simply by adding mixed liquor to a container, such as a 2-litre cyclinder, and plotting the height of the sludge/ liquid interface aga inst tim e. The slope of the straight portion of the curve represents the ISV (in metres/hour). Although the actual test is simple, there is much conjecture as to the effects of column diameter, sludge depth. DO. and application of stirring (and stirring rate)- and to the relationship of data obtained in a small container to performance in a clarifier.

Neverth eless , this approach is one of the best presently available for estimating limitation s of secondary clarifiers . The test can be eas ily perform ed on a daily basis and a relationship between MLSS concenWATER

CONCLUSIONS From the Subiaco WWTP demonstration plant and analysis of continuing operations, the following general conclusions on operation of an activated sludge facility can be drawn : 1. It is imperative to assess the unit# capacity and the physical capabilities of an existing treatment system prior to commencing any assessment of the operating capability of that system. The best operating procedures will not overcome physical deficiencies.

2. A minimum MLSS concentration of 2000 mg/L should be maintained to ensure that any odourous substances which pass to the activated sludge process are absorbed by the mixed liquor and not discharged to the atmosphere.

3. Control charts and tables should be developed for any activated sludge plant as an aid to operations and to enable alterations required to operating parameters to be readily determined .

4. To ensure satisfactory activated sludge operation it is essential th at positive solids/ liquid separation is achieved in the secondary clarifiers and that positive and rapid sludge removal is employed .

5. Daily monitoring of operating parameters, similar to those conducted for the demonstration plant, is essential for activated sludge plants if consistent operations are to be attained.

6. As the process is biological, any adjustments should be made gradually with adequate time allowed for the system to stabilise after process adjustments.

7. In areas where the wastewater temperatures are high (up to 30°C). nitrification will occur and cannot be prevented without operating in a potentially unstable range. Allowances for nitrification should therefore be made in the design and operation of any treatment plant receiving high temperature wastewaters.

8. Provided sludge is removed quickly from the second ary clarifiers denitrification in the clarifiers should not occur .

Co ntinued on page 26 21

ECONOMIC EFFLUENT TREATMENTS AND RE-USE OF WATER IN THE TEXTILE PROCESSING INDUSTRY M. W. Simmons TABLE 2. PROBABLE CONT AMIN ANTS AFTER TEXTILE OPERATION. (TEXTILE RESEARCH COUNCIL 1978)

ABSTRACT

Various techniques for effluent treatment of textile waste liquors are disc ussed in relation to the recycling of the " clean stream. " Particular reference is made to colour removal and BOD/ COD reduction.

Four st udies are reported where chemical floccul ation , hyperfiltration, no treatment and activated carbon treatment of dyeing li quors have been used successfully to conserve water, fue l. dyestuffs and chemical in recycling systems. A short precis is given of the alternatives to water in textile operations.

INTRODUCTION

Water is one of the two main ingredients in textile operation of a wet pro cess nature. Past pre-requi sites have included access to clear potable water, now re-appraisal of this aproach in poss ible . Unless consideration is given to some degree of recycl ing we may, like the U.K. and Common Market countries face hu ge efflu ent clean-up costs .

Due to public concern with water pollution, practically every Australian State, in compacts or agreement s with the Federal Government, has enacted laws and legislation for the control o f th is problem.

With the increased demands for water cleanliness for those effl uents discharged to the environment , it would appear unreaso nable to ex pend effort in producing clean effluent only to throw it away.

Therefore, th e fea sibility of re-cycling must be exam ined.

Technically the requirements for recycling are different from those for discharge to the environment. Recycl ing is technically feasible and at this point in investigative procedures, the suggested treatments proposed are biased towards less thorough ly proven physical and chemical treatments and away from estab lished biological procedures, if only to take into consideration specific parameters in textile effluents.

THE RAW MA TERI AL -

WATER

Whatever the reasons for an investigation into the feasibility of water recycl ing, the first requirement is the specification of the volumes used in the various industries, and an understanding of the contaminant levels permissable for the success ful re-use of water.

The literature sources investigated (Anderson & Wood, 1979; Funk, 1969; Textile Research Council, 1969) clearly show discrepancies in

CONT AM I NATION

SPECIF IC CONTAM INANTS

QUALITATIVE DESCRIPTOR S

Colou r

Dyestuff

Metals Organic Matter

Fe,Cu ,AI Colourless Synthetic Waste

Absorbance at specific wave-lengths of max absorption . mg/ L

Fluorescent Brightening Agents Inorganic Salts

Wool Wool Wool Wool

Scouring Carbonising Dyeing and Cleaning Rinsing

Cotton Cotton Cotton Cotton Cotton Cotton Cotton

Sizing Scouring Bleaching Mercerising Dyeing Printing and Rinsing Washing

20 - 40 5- 7 10 - 180 30 - 90 15 4 150 7 10 25 120

- 20 - IO - 180 - IO - 200 - 30 - 160

Max Simmons is Dyehouse and Technical Manager of Messrs.

Coats Patons (Australia) Ltd. , Launceston, Tasmania. This paper is based on M. Ti/l's presentation to th e 8th Federal Convention in 1979.

22

mg/ L

Na Cl, Na250c NaOCI Na OCI, H 20 2 Ca Fibre Residues P roprietary Oils Wool Grease.

mg / L mg/ L CaCo 3 mg/ L mg/ L mg/ L

both volumes and fina l contamination levels of liquors used in the industries. However, by averaging the published figures, we can arrive at an approximation that ignores speciality equipment or novel, unique systems recently introduced by textile machine manufacturers and dyestuff companies.

Tables I and 2 outline these averaged figures for water consumption and contaminant parameters.

Effluents from textile process ing contain a , wide variety of pollutants, the nature of which depend , amongst other things, on the type of processing carried out, the type of fibre bei ng treated, and the form of fibre, that is, whether loose, yarn, piece or carpet.

Table 3 (Gardiner & Borne, 1978) attempts to highlight th e waste loads of some of the principal properties M textile effluents in regard to re-use or recycling. It must be stressed that this table is an averaged result , and inevitab ly some of the ranges shown are broad .

TABLE 3. AVERAGE MIXED WASTE WATER ANALYSIS FROM TEXTILE MILLS

PROCESS

LITR ES/ KILO

Proprietary OBA' s

Oxidants Hardness Suspended Matter Oils and Grease

TABLE I. AVERAGED WATER QUANTITIES IN THE TEXTILE OPERATION

OPERATION

COD mg / L OBA

Wool Scouring and Dyeing Cotton Dyeing Polyester Dyeing Nylon Dyeing Cotton Processing

S.S. mg / L

pH

COD mg/ L

BOD mg/ L 360 2400 400 1800

120

8.5-9

1920

200

5-8

2700

96

4-6

634

292

75

7 - 11

810

4 - 12

1000

380 200 1800

30-300

DET. mg/ L

90 7

Na + ppm 400 1200 280

5 10

400

40

400

TRIAL RESULTS OF RECYCLING TREATED AND UNTREATED TEXTILE WASTE TO DYEBA THS Cotton Mill - Chemical flocculation (Shomakers 1977.)

The classes of dye most frequently used in th is mill were d irect dyes, vat dyes and reactive dyes .

WATER

The waste water arising was made up of the following baths Direct Dyes: 1200 litres dye bath 2400 litres rin se liquor

• A E Values are measures of colour difference; the higher the number the greater the difference . Subjectively, a n ~ E of I .4 indicates a shade difference that can just be discer~d by an untrained observer.

3600 litres total.

Vat Dyes:

1200 2400 1200 1200 1200

litres litres litres litres litres

dye bath rinse liquor oxidation bath soapy bath rinse water

7200 litres total.

Reacti ve Dyes:

1200 2400 1200 2400

litres litres litres litres

dye bath cold rinse water hot rinse water rin se water

7200 litres total.

The composite bath s, after exhaustion, (that is the conversion of dye in bath to dye in fibre) had the following composition: COMPONENT Direct Dye Sodium Sulphate Softener Calcium Hexametaphosphate Sodium Carbonate Acetic Acid Vat Dyes Sodium Hydroxide Reactive Dyes Sodium Chloride

PROPORTION OF ORIGINAL BA TH lOOJo 100% 50% 100% 100% 100% 10% 100 % 10% 100 %

The COD was found to be 400 mg/ Land the waste water was turbid and dark in colour. Chemical reagents were added in the following proportion 860 mg/L Alkali Heavy Metal Salt 675 mg/L Floccu lating Agents 10 .5 mg /L The effluent was pressed into an inj ector where fine bubbles mixed with the floes. The flotation products were then skimmed . Chemical analysis of clear liquor after flocculating and skimming were as shown in Table 4.

TABLE 4. ANALYSIS OF EFFLUENT COD pH Hardness Salts (by conductivity)

190 mg/ L 7.2 4° Clarke 3876 u/ second / cm @ 20°c.

The troublesome products are the inorganic sodium salts - Sodium Sulphate, Sodium Chloride, Sodium Carbonate, which are in the dyeing recipe.

These salts are degraded sparingly; because most recipes in this mill relied on sodium su lph ate, an attempt was made to modify the individual dyeing recipes to allow for the content of sodiu m sulphate already present in the recycled water. Tab le 5 summarises the composition of recycled water after eac h dye cycle and after chemical flocculation. Recycling dye liquors for up to five times with intermediate chemical flocculation was successfu l from the viewpoints of maintaining colour continuity and quality of the product as,'.\. E Values• were less than 1.5 (in comparison with the shade ach ieved using uncontaminated mains water).

Comparative maximum A E Values for recycling experiments using the three dye classes were as follow s: Ll E. Direct Dyes Vat Dyes Reactive Dyes

WAT ER

1.4 1.0

0.9

TABLE 5. ANALYSIS OF DYE LIQUOR AFTER CHEMICAL FLOCCULATION ANAL YSlS OF USED LI QUORS AFTER 2nd TREATMENT

3rd TREATMENT

4th TREATMENT

7.1 675 247

7.2 807 253

7.3 585 285

7.2 620 290

7 .3 620 264

64"7o

68.6"7o

5l. 3"7o

53.2"7o

57.4"7o 23.5 3.5 1.4

1st DETERMINANT TREATMENT pH COD In CO D Out Degradation in COD Salt Content as NaSO 4 Hardness Clarke 0 !i. E Values•

5.9 g/ 1

9.3

14. 1

a.

19. 15

3.5 0.9

2.25

3.5 0.8

3.5 1.1

1.3

5th TREATMENT

Man-Made Fibre Mill - Reverse Osmosis or Hyper-Filtration.

(Brandon, Nasher, Porter 1975 .)

Reverse osmosis or hyper-filtration can be applied to dye liquors.

Three types of dyeings can be cons idered • Separate and indepen dent dyeings employing only the ultra filtrate as the new dyeing bath , or • Using only the concentrate residue with its chemicals and residual dyestuff, or • Using one dyeing sequence where the ultra-filtrate is used as the dye bath medium and the concentrate is used wholly or in part in the same bath for reuse of the dyes and chemicals in the concentrate .

Having collected the input process water, membrane filtration was used to separate the dye and chemical residues from the clean ultrafiltrate . Test dyeings were carried out in the laboratory so that plant scale formu lations could be developed . The plant recipe or form ulation and the dyeing time/ temperature cycle were then given to the plant dyer to conduct the dyeings.

Two o bjectives dictated the selection of shad es to be dyed(!) Selecting shades in the immediate production schedule and adding whatever dyes were needed to majch the shade, or (2) Selecting a shade in the range that was nearest to that produced by the concentr ate and which required minimal amounts of additional dyes .

Table 6 summarises the comb ined feed water before hyperfiltration, the purified ultra-filtrate and the concentrate after six successive dyeings each followed by hyper-filtration. This trial was successful, but further rotation would be restricted by turbidity caused by accumul ation of colloidal textile residuals.

TABLE 6. ANALYSIS OF HYPER-FILTRATION STREAMS

DETERMINANT pH BOD mg/ I COD mg / I Turbid ity Total Solids mg / I Colour (H aze n) Hardness as Ca mg /I

Woo llen Mill -

COMBINED FEED WATER

ULTRA FILTRATE

6.6 15 170 55 780 595 45

7

CONCENTRATE

I

25 6.3 285 90

IO

7.4 IO

435 80 3425 11 20 140

No cleanup treatment of dyebath liquor

A series of three experiments has been performed on dyebath recycling witho ut treatment but with adj ustment of pH or ionic strength (conductivity) or both.

23

The dyed goods were assessed for commercial acceptability, the criteria for commercial acceptance being reproducibility of shade without detriment to any fastness tests.

The dyeings were made on 80/20 wool/ nylon carpet yarn and normal handknitting yarns.

The experiments were designed for control by analytical monitoring which may be easily carried out in any dyehouse, by aiming for high conversion from dye in bath to dye in fibre, and by maintaining a constant pH and/ or ionic strength of the dyebath liquors. Hence the only moni toring equipment necessary was a pH meter and a conductivity meter .

The experiments showed that satisfactory dyeings with acid levelling and acid milling dyes may be achieved using dye liquors which have been recycled up to 16 times . Apart from considerable savings in chemicals, in addition to savings of water consumption, there were significant savings in effluent charges and fue l (by recovery of heat from the exhausted liquor at 80°C ex the dyebath.)

The results of this series of experiments are summarised as follows:• Water savings ranged from 27 - 620/o .

• E ffluent charges based on a COD, Suspended Solids, pollution load equation were reduced by between 11 OJo and 580/o.

• Fuel savings ranged from 200/o - 400/o.

• C hemical savings based on acid and sodium sulphate ranged from 570/o - 800Jo. • There was no deleterious effect on shade levelness or colour fastness.

• The number of cycles possible was limited by protein precipitation caused by prolonged boiling increasing the turbidity and suspended solids and impairing the final dyed finish .

Thi s paper has reviewed method s of efflu ent treatment app lica ble to the textile industry where the resulting "clean " stream may be reused a number of times with or without prima ry treatment.

Results have shown that in some organisations, total reuse of water is possible withou t recourse to any treatment. In other areas, primary treatment of dyebath effluents can be performed to bring them to a level suitable for reuse. In some cases the economics are doubtful at the present time.

The situation will change in the future with increased knowledge of what the textile technologist requires. At present in Au stralia the effect is to make wholesale treatment for reuse at least as costly and probably much more costly than treatment for discharge.

In these circumstances, recycling without treatment can be the only financially acceptable route. This can only be justified if the additional cost is lower than the cost of the raw water supply. Th e exercise is therefore likely to be attractive where more expensive water is employed , and may be technically imperative if water is in short supply throughout the year or in specific locations.

The use of activated carbon for the removal of organic loads

REFERENCES

This process is both practical and economic for the removal of organic loads from textile effluents.

From a case study (Rhys 1978), conducted from 13 American mills covering cotton, man-made fibres, silk and wool, there was an average of 940/o removal of total organic carbon (T.O.C.,) a 980/o reduction in colour absorption limits and a 1000/o reduction in American Public Health Authority Limits (Hazen Units) (Table 7) .

ANDERSON , C. A. a nd WOOD, G. F. (1979) . Tex tile Effl uent s and Their Trea1men1. Textile Journal Australian Vol 28, No. 10.

BRANDON, C. A., NASHER, A. E. and PORTER, J . J. (1975).

Hyperfillra1ion Pil o1 Plan1 for Tex tile Was 1c Wa1er Renovati on.

American Dyestuff Reporter, Pages 20-44 , October.

FUNK , J. W. (1969) . Industrial Wa1 er and Efflu e111 Management in 1he Tex til e Indu str y. South Afri ca n Co un cil for Sc ientifi c and Industrial Research.

GARDNIN ER, D. and BORNE, B. J. (1978 ). Tex tile Was te Waters: Treatm ent and Environment al Effects. JSDC 94 (8 ) 339.

KO ETH , (1977). Tex til e So lve nt Tec hnology . AATC Sy mposium , Page 127 , January.

LOV E, R. (1976) . Wh a1 Happens Wh en 1he Industry Run s Dry.

TABLE 7. REMOVAL OF TOTAL ORGANIC CARBON FROM MIXED TEXTILE WASTE WATERS

ITEM

UNTREATED FIL TE RED EFFLUENT ONLY

CARBON FILTERED

ORG .

MATTER RED ' N

9-4670 290

9-3335 183

1-440 17.4

75 -99% 94 %

0 .02-5.4 0.56

0.02-1.64 0.29

0.005-.09 0.01

78-100% 98%

50-7000 480

0.3 -3500 410

T.O.C.

Range Median Colour Absorbance

Range Median Hazen Units

Range Median

0-15 0

98-100% 100%

ALTERNATIVES TO WATER IN TEXTILE PROCESSING SOLVENT PROCESSING The success of this operation depends on dyestuff manufacturers marketing special forms of existing dyes . Colour yield (i.e. depth of shade/ unit of dye added to the bath) as shown by Kothe (1977) in the use of perchlorethylene on dyeing polyester fibres demonstrated that of 1100 additive-free disperse dyes studies, only one gave a colou r yield greater than 500/o (where 1000/o is the depth of shade produced by aqueous dye-bath.)

Whatever solvent is used for dyeing or textile preparation, finishing, water will have been involved in its manufacture so that water usage will still be finite. Preparation and finishing in the same solvent should be possible, thereby reducing handling costs and eliminating costly intermediate drying processes. Love (1976), showed that solvent dyeing improves levelness and attains shorter dyeing cycles but the req,very of unused dy:stuff fro~ the dye bath after dye-

24

ing and the expensive reclamation of gaseou s solvent s added to the overall cost.

Pollution is not avoided . Fibre impurities, oils ~ nd spinnin g assistants concentrate in the solvent and these will require disposal. Solvent retention by the fibre s will lead in evitably to air pollution .

However, it would be wrong to totally di smi ss solvent dyeing . It is one of a number of options available to the dyer in his efforts to conserve water and to guarantee continuity of production where water is in short supply.

CONCLUSION

JSDC 92 380 .

SHOMAKER S, P. (1977). Dyein g Trials wi1h Treated Tex tile Waste Water. In t Textile Bullentin, 4/ 77, page 4 14 .

Tex til e Research Co un cil ( 1987 ). Wa1er ' Qu alit y Requirement s and Waste Wa1er Recycling in 1he U.K. Tex tile Industry.

RHYS , 0 . (1978). Absorption on Ac1i va1ed Ca rbon. JSDC 94 (7) 293 .

JOURNAL SUBSCRIPTIONS AUSTRALIAN WATER AND WASTEWATER ASSOCIATION - 1981 Subscription to the Journal for 1981 is increased to $8 p.a. or $2 per issue, inc luding surface mail to al l countries .

SIMMONDS & BRISTOW WATER & WASTEWATER CONSULTANTS ANALYTICAL INVESTIGATIONS Water Sewerage & Industrial Wastewater POLLUTION PREVENTION Process & Pilot Plant Investigations Treatment Plant Operations & Control WATER BACTERIOLOGY Algal Iden tifications Environmental Surveys CORROSION Assessment & Prevention 30 Shottery St., Yeronga - Phone: (07) 48 7699 If no answer 202 6534

WATER

CALENDAR-1981 PEOPLE -

MONO PUMPS

February-March, Perth

Perth Metropolitan Groundwater, (CSIRO / WRFA) .

March, Noordwijkerhout, Netherlands

International symposium on the quality of groundwater. (Neth . Inst. for W.S.).

March 23-27, Canberra

I.E. Aust. 1981 Engineering Conference.

March 30-April 1, Berlin

Wasser Berlin '81.

March 31-1 April, Berlin

IWSA specialised conference on low cost technology in water supply.

April 2-3, Berlin

IWSA specialised conference on instrumentation monitoring and automation in water protection and supply.

April 6-10, Perth, Australia AWW A 9th Federal Convention. ~fay 3-7, Bratfslavla International conference on numerical model ling of river, channel and overland flow .

(IAHR , WMO, HASH) .

May 11-15, Brisbane

51st ANZAAS Conference.

May 18-21, Melbourne

Seminar on drainage of agricultural lands .

May 22-24, Wallingford, U.K.

Practical Techniques for Regionalising and transferring Hydrological Variables (Inst. of Hyd .).

June 8-13, Kuala Lumpur

Groundwater '81.

June 14-19, Urbana, U.S.A.

2nd International Conference on Urban Storm Drainage (IAWPR).

June ?? , Toronto, Canada 2nd Symposium on Interaction of Sediment and Fresh Water (UNESCO) .

June 15-19, Brighton, U.K.

Water Industry 1981.

June 20-26, Munich and Rome Water quality monitoring (IA WPR) .

Groundwater Hydrology, Short Course (Murdoch University.

August 1981, Grenoble, France

11th Int. Irrigation and Drainage Congress (ICID).

August 10-14, San Francisco

Water Forum 1981 (ASIE).

September, Melbourne

Hydrology Symposium.

September, Jonkoplng, Sweden

International Trade Fair and Conference on water conservancy and pollution control.

September, West Germany

Congress

on

Metallic

September 6-12, Travemunde, Germany

2nd International Symposium on Anaerobic Digestion.

September 7-11, Lisbon

Int. Symposium on Water Resource Management in Industrial Areas.

WATER

Mr. E. F. Bird has moved from Melbo urne to New Zealand where he has taken up the pos ition of Manager and Director of Mono Pumps (New Zealand) Limited.

He was previousl y Austra li an Sales Manager of Melbourne based Mon o Pumps (Aust.) P/L. The previous Manag er of Mono Pumps in New Zealand , Mr. F. R. Edwards has been assigned new responsibi lites for Mono Pumps in another part of the world.

For further information contact Mr. G. H. Snow , Managing Director, Mono Pumps (Aust.) Ltd.

SHARPLE-STOKES SUPER¡D-CANTER CENTRIFUGES In April last, Sharp ie-Stokes Division of Pennwalt Corp . was awarded by the City of New York Authority an $11.8 million order for Anaerobic Sludg e Dewatering Centifuges .

As part of the tender submission, all tenderers for th e project were required to test their equ ipment in one of the Authority 's Sewerage Plants .

All testing was by t h e City 's Eng ine ers. All Sharples and other centrifug e tenders did was to install and operate their equipment. The Cit y of New York Supervising Engineers carried out all collection and ana lysis of samp les, the recording of f low rates, recording of polymer dosages and all other read ing s.

Tis procedure was followed to enable true assessment of performance and to ensure equitable and valid comparisons during th e side by side testing of tenderer 's submiss ion s.

DIVERSEY

July 6-10, Perth, W.A.

8th International Corrosion.

PRODUCTS -

Bacteria for Methane Produ ction The Warne Biolytics (Europe) Company of Dublin has for several years been producing packaged specialised micro-organisms for aerobic waste treatment. These are valued highly throughout the world, particularly in Europ e. (Refer " Wat er", June and December, 1979).

The latest from W.E.B., now undergoing field trials in Europe, is Methanobac, designed to improve the effic iency of anaerobic digestors and thereby increase methane production .

Indications at this stage are good and the product will soo n be avai lable in production quantities.

The Australian Distributors, Diversey (A'Asia) Pty. Ltd ., will be pleased to arrange samples for evaluation and to discuss possible trial sites . Contact John Abery, Diversey (A'Asia) P/L, 31 Berry St., Bayswater, 3153 (03-729-5600).

COMMENT

WRIGHT & CbMPANY T h e Co mpany announces the appointm ent o f Mr. A. (Andy) S. Kastanias as Product M an age r , Activat ed Carbon and Assoc iat ed Produ cts .

Mr. Kastanias is a Graduate of the Univers ity of N.S.W. - B.Sc .(Hon .) and h as considerable ex p erie n ce in analytica l chemica l work and in the producti o n of q u alit y controlled pharmac eut icals.

He deal s with activated carbo n and similar product s, appli ed technol og y and marketing activ iti es.

BINNIE & PARTNERS CONSULTING ENGINEERS Announ ce the follo wing changes.

1. The firm is now known as Binni e & Partners Pty. Ltd . with Director s Michae l Oddle , R. De V. Gibbs and T. G. Hammond . The firm now practices from new offices , 180 William so n St. , Melbourne , 3000.

2. Ken Rippin , Manager Perth , has transferred to Binnies , Hong Kong . The Perth branch will continue to practi ce at London House, 214 St. Georg e's Terrace, Perth under a new Manager, John Prior.

The firm also announces the estab li shment of a Queensland pract ice to be known as Binnie and Partners (Queensl and) P/L. This is a separate firm with Di rec tors R. De V. Gibbs , M. F. Odd le and T. G. Hamm ond and offices at National Bank Building, 420 George St. , Brisban e under Manager Graham Tombs .

AUSTRALIAN RAINFALL AND RUNOFF

• 5.1 Metric 1977 ERRATA (JULY 1980)

Cop ies of this errata wil l be provided free of cost if a stamped self addressed envelope is sent to 'Australi an Rainfall and Runoff' , Th e In stitutio n of Engineers , Au stralia, 11 National Circuit, Barton , A .C.T. 2600 .

'WATER' COMPUTER REFERENCE Throu gh the cooperation of th e Water Research Centre, Stevenage, U.K., 'Water' will in future be abstracted for inclusion in 'WRC Information ' and subseq uent storage in the WRC computer readable data base AQUALINE. This should be accessible in Australia via the DIA LOG Information Retrieval System.

The data base of the South Afr ican Water Information Ce ntre WATERLIT ha s included 'Water' in its coverage si nce 1976.

WA TERLIT is bei ng added to the U.S. System Development Corporation Orbit information sys tem which is available through many libraries in Australi a .

25

SANDFORD D. CLARK Continued from page 13

M. R. TILL Continued from page 17

In the interven ing years, countervailing factors have attracted attention. It has been realised that appropriate equipment in skilled ha nd s can reduce, if not eliminate, the danger of permanent or long-term damage to aquifers and the unnecessary depletion of supplies , and can also increase the efficiency of bores. The community's in terest in maintaining and conserving the resource is thus served by the licensing of drillers, and potential consumers are also protected from possible losses which can result if incompetent drillers are engaged. The possibility of using properly qualified drillers to ass ist in providing accurate and useful data also serves wider community purposes.

These wider community values were ultim ately seen to outweigh other factors and it is interesting to observe that, at much the same time , legislation began to require that wider community interests be considered in deciding whether licences to construct and use bores should be issued. The decision to require that drillers be licensed may thus be seen as part of a change in emphasis of groundw ater policy to ensure the even distribution and continued availability of the resource.

Legislation requiring drillers to be licensed now exists in all States other t han Western Australia and seems to be an important tool, not merely in ensuring that wells are properly constructed , but also in ensuring an effective flow of planning data.

Landholders again became involved in determ ining water management techniques when four a ppealed in the Water Resources Tribunal against conditions of th eir licences . After a hearing extending o ver severa l month s the pr inciple of water allocation by land use control was uph eld by th e lu ce rne equi val ent for the crop type of th e a ppella nt was chan ged.

The effect of comm unity involvement at various levels ,on the acceptance of the method of water allocation has not been quantified.

However, it is the fee ling amongst the growers and the administrators of the controls that the system is working well. It is the author 's opinion that this is du e to the apparent justice, logic and objectivity of the technique and the involvement of the comm unity in its development and imposition , but perhaps most importantly to the conviction of the irri gators that some restriction on water use was essential.

REFERENCES IO Thorpes Lid. v. Grant Pastoral Co. Pty. Ltd ( I 955 ) 92 C. L. R. 3 I 7, 33 1. See a lso Rapoffv. Velios [1975) W.A . R. 27.

II Frazier v. Brown ( 186 1) 12 Ohio St. 294,3 11.

12 See1 he ge nera l scope ofWa1erAc1, 191 2 (N .S. W.) ,ss . 11 2- 188A ; Wa1erAc1 1926- 1979 (Qld .) , ss. 54F-63 ; The Pas to ra l Act , 1895 (S .A. ) a nd a mendin g a nd replace ment Acts in 1904, 1922 a nd 1929 ; Ri ghts in Wa ter a nd Irriga tion Act, 191 4- 1978 (W.A.) , ss. 18-24.

13 See Wa te r Resources Act 1976-1979 (S. A .); Undergro und Water Act 1966 (Tas.); Ground wa ter Act 1969 (Vic.) .

14 G ro undwa ter Act 1969 (V ic. ), s. 5 1.

REFERENCES GE RNY , J . S ., SH E PH E RD , R. G., S H E PH ERD R. C ., BOW E R ING , 0. J. , HARRI S, B. M., C LA RK , R. D . S., KILLO C K, J . C., C LI SBEY, R. L . , BE ARE, J. A. , Till , M. R ., HOLM ES, J . W ., ALLI SON , G. 8 ., BOW E N , W. J., W E INE RT, R. M . a nd FARW ELL D. L. Pa dihawa y Area Wa ter a nd Sail Ba la nces, So uth -Ea st Wa ter Reso urces ln ves tigaiion Commiu ee Report No. I - Febru a ry 1975. Engi nee rin g a nd W ater Suppl y Departm ent , South A ustralia, Fil e No . EWS 4956/74 Libra ry Re ference EW S 75/2 .

GE RN Y J. S. ed. al. op. cit.

GERNY, J. S. et al. op . c it.

HARRI S, B. M . South Eas t Waier Reso urces - Padth away Area Report on Hyd ro logical In ves tiga ti o ns. Depa rtm ent of Mines, So uth Austr alia, Report Book 7 1/ 190.

ALLANJ.GALE Continued from page 21 9.

BARRY T. HART Continued from page 15 REFERENCES G .H .&D. ( 1978). Planning for the Use of Sewage, Gunerid ge Haskins and Dave y, M elbourne.

GRAHAM, W. A. E . ( 1979). The Prese nt Posit ion with Ri ver Sa lin ities in Vicwria . Paper Presented al Au lralian Water Researc h Foundation Symposium , Melbourne, August I 979.

HART , B. T. (1974). A Compilation of Australian Water Qualit y C riteria, AWRC T echn ical Report No. 7, Au st. Govt. Printing Service , Ca nb erra.

HART, B. T. (1980a). En vironmental Surveys, Chapt er 20 in W . D . Williams (Ed.}, An Ecologica l Basis for Wate r Resources Manage ment , Au st. Nationa l Un iv. Press , Canberra (in press).

HART , 8. T . (1980b). Australia n Wa te r Quality Cr it eria , Cha pte r 11 in W. D. William s (Ed.), An Ecological Basis for Water Reso urces Manage ment , Aust.

National Uni v. Press , Canberra (i n press).

JENK IN, J . J. (1979) . Dryland Sa ltin g in Victoria. P a per present ed a1 Australian Wat er Resea rc h Foundation Symposium , M e lbourne, A ugust 1979.

MALCOLM, C. V. and Stoneman, T. C. (1976). Sa lt Encroachm ent - The 1974 Salt land Survey. J. Agric. West. Aust. , i 7, 42-49 .

MATHESON, W. E. (1968). When Sa lt Takes O ve r. J. Agric. South Aust., 71, 266-272.

MILLS, B. J ., Lake, P . S. a nd Swa in , R. ( 1979). Two Freshwater Cru staceans Suitab le for Toxicity T ests in Au s tralian Wa ters. Water Stud ies Centre T echn ical Report No. 10, Caulfield In stit ute of T ec hno logy, Caulfield East, Australia.

PECK, A. J . (1978) . Sa linization of Non -Irrigated Soils and Associat ed Si reams: A Re view. Aust. J. So il Res., 16, 157- 168.

PECK, A . J. and H URLE , D. H . (1973). Chloride Ba lance of Som e Fa rmed and Forested Catchments in South Western Au stralia . Water Resources Res., 9, 648-657 .

PECK , A. J. , WILLIAMSON , D. R. , BETTENAY , E. and DlMMO C K, G. M .

(1973). Salt and W a te r Balances of Some Catchm e nt s in the So u1h-Wes1 Coast Drainage Di vision. Inst. En g. Aust. , Na tio nal Con f. Publ. No. 73/ 3, pp. 1-4.

W ILLI AMS, W . D . (1976). Some Pro blems for Australia n Limno logists.

Search, 7, 187-190.

26

For a plug flow system it is essential to maintain DO concentrations of 1 mg/ L or better at all times and at all locations within the aeration tanks . If there is any doubt as to the attainment of this objective, a series of DO profiles covering the width , length and depth of aeration tanks shou ld be carried out.

10. DO concentration is extremely significant when assessing the oxygen transfer efficiency of the activated sludge system and is much more significant than temperature . T he higher the DO in the system t he lower the transfer efficiency.

11 . There appears to be a lack of information on the oxygen transfer efficiency of various aeration sys~ms and the need for such information is becoming more significant from an energy conservation viewpoint. Because of this lack of information, it is possible that treatment plant design to be either too conservative, resulting in larger than necessary oxygen facilities ; or too optimistic, res ulting in insufficient oxygen being available at times of peak loads .

ACKNOWLEDGEMENT The a uthor thanks the Comm issioner, Mr. H.J. Glover and the Chief Engineer, Mr. H.E. Hunt , of the Perth Metropolitan Water Supply Sewerage a nd Drainage Board for permission to publish this paper.

REFERENCES ANTHON ISEN, A . C., LOEHR , R. C ., PRAKASAM , T. B. S. AND SR!NATH , E.G . (1976) . Inhibitio n of nitrificatio n by ammonia a nd nitrous acid . JWPCF48 No . 5.

WONG -CHONG AND LOEHR (1978). Kin etics of m icrob ial nitrificat ion: nitrite-nitrogen oxidatio n. Water Research 12 No . 8 . 605-609.

COOPER , P. F., DRE W , E . A., BAIL EY, 0. A ., THOMAS , E . V . (1977a) .

Recent advances in sewage effluent demitrificat ion: Part I. JIWPC 3.

COOPER , P . F ., COLLINSON , 8 ., GREE N, M . K. (1977b). Recent ad vances in sewage effluent demitrification: P a rt 2. JIWPC 4.

REMEMBER! 9th AWW A CONVENTION PERTH - APRIL 6-l0th WAT ER

LETTERS DISCUSSION 'WATER QUALITY MANAGEMENT OF STORAGE RESERVOIRS - D.W. LYNCH' [WATER, SEP. .

1980) .

FROM F .L. BURNS

Dr. Lynch is to be commended for his Paper on a subject which is justly rece iving increased attent ion from water supp ly engineers throughout the world - the control of water quality in the reservoir itself. In the past it h as been recognised that changes take place in the qualit y of water stored in reservoirs particularly deep reservoirs - over which we have had very little control. This has forced us into co nsiderable ex penditure on selective withdrawal fac ilities, water treatment works, and swa bbing of main s. to solve problems which it is now becoming possib le to solve at a fra ction of the cost by artific ia l m anipu lat ion of the natural reservoir limn ologica l cycle .

This chang in g situat ion has come with the clea rer und ersta nding of the limn ology of rese rvoirs. generated by such assoc iat ions as T.he Austra li an Society for Limnology and resea rch fundin g by bodies such as The Austra li an Water Resources Cou nci l.

Dr. Lynch m a kes m ention of my article in th e S.R. & W.S.C. journal Aq ua in 1977. on destratifying Tarago reservoi r . Thi s was a ve ry ea rly artic le on th e subject, and anyone interested will get much more information from the final report, published last year, on th is three yea r resea rch project , financed by The Australian Wate r Resources Council.

Thi s 240 page report by Barbara Bowles , Joan ? ow ling a nd myself contains considerab le detail of the design, operation and costs of destratifying Tarago reservoir , together with th e phys ical. chemical and biological effects, and is ava ilabl e from Government bookshops as A.W.R.C. T echnical Paper No. 46.

This report was not avai lable to Dr. Lynch when he wrote his paper a nd I suggest he rev iew his estimate of cost for destratifying Sugarloaf Reservoir usin g the design principles and cost data contai ned in it.

Alth o ugh larger than Tarago reservoir, Sugarloaf, with a ca pacity of 9S,OOO ML, is not a particularly large reservoir for destratification. We have destratified Eppa lock reservoir (311,000 ML) with an installation capital cost of $20,000 and $800 per month operating cost. and simi lar results have been obta ined destratifying Darwin River Dam (230,000 ML) and Cas it as Reservo ir (300,000 ML) in Ca lifornia.

I cannot see how an est imate as high as $270,000 cap ita l cost and $13,000 per month operating cost cou ld be arrived at for destratifyin g Sugarloaf reservoir , but unfortunately such estimates, based on incomplete information, are being made to the detriment of introduction of this economical and effective reservoir management technique .

In February 1979 we he ld a Join t U.S ./Austra li a Seminar a nd Workshop in Melbourne o n reservoi r destratification to improve water quality financed by the Austra lian Depaitment of Science and the U.S.A. Nat ional Science Foundation. The proceedings of this meet ing edited by Joan ?owling a nd myself. conta in the data and

WATER

experiences of the 26 Australian and American delegates who between them had been associated with 37 reservoir or lake' mi xin g projects. goin g back to 1962 . This is at present being published by the A.W.R.C. On e of the attractive features of destratification as a rese1-voir management tool is that the most ex pensive part of th e installation , the comp ressor sta tion, is above water where it can be readi ly maintained . modified or its cost substantially recovered if no longer req uired.

In fact th e compressor stat ion need not be built until after the effectiveness of the installatio n ha s been proved using hired compressors. The underwater works (aerators . a nd pipework) cost relatively little, and, while they ca n be placed in a n existin g reservoir , a more satisfactory and durable installation can be bui lt into the reservoir during construction.

The underwater portion of the $100 ,000 destratification insta llation for Dartmouth Rcse1-voir (4 ,000.000 ML) was built in during const ru ct io n at a cost of only $2S,0OO. This sugges ts t hat the relati vely minor cost of providing the und erwate r works (based on adeq uate design studies) for subseq uent destratification would be well worth inclu d ing in the construction cos t of all reservoirs, to a ll ow th e future use of this reservoir water quality m anageme nt technique if required .

Thi s would be advisable even where a mu ltiple leve l offtake structure is provided . sin ce th e situation can arise. as it did with t he Darwin Ri ver Dam, where alga l problems at th e upper levels. and dissolved Fe and Mn problems at the lower levels. make destratification the only option avai lable for providin g good qu a lity water from the reservoir.

F . L. BURNS , Designing Engineer, State Rivers and Water Supply Commission.

REPLY BY AUTHOR The Editor The primary objective of destratifying stored bodies of water is usually either: • to improve water quality with respect to such characteristics as temperature, dissolved oxygen , iron and manganese, and / or • to reduce/ control the concentration of algal standing crops The work done by the SR & WSC (at T arago Reservoir) and by others has shown that artificial destratification is very often an effective and low cost method of achieving the former objective. Furthermore where it is effective it is invariably much cheaper than the alternative options , such as a multiple level offtake structure , or providing some or additional treatment. The other facilities may still need to be provided for flexibility in reservoir and treatment p lant operation.

Only a relatively simple system including a single diffuser header at a single location is needed to achieve the former objective.

Further it requires only relatively low mixing energy inputs and infrequent operation. The capital and operating costs of such a destratification installation at Sugarloaf

Reservoir would be somewhat lower than those indicated in m y article, but it is doubtful whether they wou ld be qu i~ as low as implied

by Mr. Burns.

The work done on the use of destratification primarily or solely to achieve the latter objective has to date been far from conclusive.

Performance and effectiveness seem largely to be site-specific. In some cases destratification has increased algal standing crop concentrations while in other cases it has decreased them.

Destratification is not yet a proven water quality management technique in this regard.

A lot more work needs to be done : • to clarify the mechanisms which are important in achieving reductions in algal populations, and • to establish the important.design parameters and correlations.

Only then can accurate cost estimates be determined. At present reliable information can on ly be obtained from operation of a trial facility (preferably on a small scale) at the proposed site.

The costs presented in my paper for an artificial destratification installation for Sugarloaf Reservoir were estimated on the basis that a system could be designed to minimize a lgal populations. As stated the costs were preliminary only and, on the basis of present knowledge, represent a reasonable upper limit estim ate of the true total cost of such a system.

The costs include provision for such items as: • injection of a ir at several locations throughout the reservoir , using a compressor mounted on a floating platform; • adequate compressor capacity to ensure the contents of the reservoir can be rapidly mixed and algae taken on a light limiting path of maximum duration (this implies greater mixing energy than previously); • design overheads and other a llowances associated with provision and installation of the system; ., • energy for continuous operation; and, • manpower, including not only those personnel actually operating the system but also those associated with monitoring and evaluation of its performance and specification of its operating programme.

It is noted, for example, that translation and updating of the US costs of Fast et al.

(ASCE Proc. 102, EE6 , pll 7S 1976) for a sophisticated system for hypolimnetic aeration (an operation not dissimilar from destratificat ion) would indicate capital and operating costs, much higher than those suggested by Mr Burns and closer to those indicated by my paper.

Even on the basis of the higher costs it seems fairly obvious that artificial destratification is invariably a much cheaper option for improving the quality of stored water than the available alternatives. This is the point which needs to be emphasized .

The acceptance of artificial destratification as a water quality management technique will largely depend on the extent to which future research can demonstrate its practicability for minimizing algal populations.

DAVIDW.LYNCH 27

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