Water Journal June 1977

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Official Journal of the AUSTRALIAN WATER AND WASTEWATER ASSOCIATION IVol. 4 No. 2, June 1977 Price $1.00I Registered for posting as a periodical -

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EDITORIAL COMMITTEE Chairman: C. D. Parker Committee: G. R. Goffin G. R. Scott F. R. Bishop L. C. Smith Joan Pawling R. L. Cllsby A.G. Longstaff B. S. Sanders E. A. Swinton W. Nicholson J. H. Greer A. Macoun Editor: Publisher: B. J. Murphy A.W.W.A

BRANCH CORRESPONDENTS CANBERRA A.C.T.: A. Macoun, P.O. Box 306, Woden, 2606.

NEW SOUTH WALES: G. R. Scott, James Hardie & Coy. Pty. Ltd., P.O. Box 70, Parramatta, 2150.

VICTORIA: M. Smith, Ministry of Water Resources and Water Supply, 9th Floor, 100 Exhibition St., Melbourne, 3000. · QUEENSLAND: L. C. Smith, 24 Byambee Street, Kenmore, 4069.

SOUTH AUSTRALIA: R. L. Clisby, C/- E. & W. S. G.P.O. Box 1751, Adelaide, 5001 .

WESTERN AUSTRALIA: B. S. Sanders, 39 Kalinda Drive, City Beach, 6015.

TASMANIA: W. Nicholson, 7 Swansea Court, Lindisfarne, 7015.

NORTHERN TERRITORY: C/- N. R. Allen, 634 Johns Place, Nightcliff, Darwin, 5792.

Editorial Correspondence: B. J. Murphy, Box 125, Chelsea, 3196.

Or to State Correspondents.

Advertising Enquiries: Mrs L. Geal, C/- Appita, 191 Royal Par., Parkville, 3052.

Phone: (03) 347 -2377.

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1,ssN0310

03s1 J

Official ..Journal of the !AUSTRALIAN WATER ANDI

,...

l'ASTEWATER ASSOCIAT.!lm]

• •

Vol. 4, No. 2, June, 1977

CONTENTS Editorial ....

. ...

5

Association News

6

Cadmium and Lead In Port Phillip Bay Mussels....

8

The Dartmouth Dam Environmental Survey

12

Land Conservation Council, Victoria, Final Recommendations on the Melbourne Study Area . . . . . . . . . . . .

15

The Destruction of Waste Cyanide with Hypochlorlte....

....

16

Recent Developments In Hydraulics Within the Hydroelectric Commission of Tasmania - Part 2

18

Operator Training In Victoria

22

... .

.. ..

Environmental Studies Course In 1978

23

Waste Exchange

23

Conference Calendar

24

Products, Processes, People

25

• INSTRUCTIONS TO AUTHORS Articles should be of original thought or reports on original work of interest to the members of the A.W.W.A. and preferably not more than 5,000 to 7,000 words.

Full instructions are available from Branch correspondents or the Editor.

FRONT COVER Excavation of the cascades at the Dartmouth Dam site. Rock from the cascade excavation is being used in the construction of the 180 m high central core rockfill embankment of 14 million m 3 volume which will impound 4 million Megalitres of water on the Mitta Mitta River in North-East Victoria.

Measure conductivity anywhere with Beckman laboratory and field conductivity bridge.

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The RC-16C can be operated using any of three convenient types of power sources (dry cells, rechargeable nickel-cadmium batteries, AC line). Reliable , solid state circuitry provIaes Iong, maIntenance-rree serv,ice, ensures low current drain on batteries. Tough, shock resistant, molded ABS plastic case with protective cover allows you to carry RC-16C anywhere conductivity measurements are made.

BECKMAN® New Beckman Model RC-16C Portable Conductivity Bridge for use In Laboratory or Fleld .

For full information on Beckman Mode l RC-16C laboratory and field conductivity bridge, contact the Selbys office in your state.

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this is; drin~ng . water -¡

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It has just travelhiJd through 8 power stations, generate 15 million unlts of

it is still Water and mountains are the natural ingredients of our electricity.

We wouldn't want to spoil either of

3

The Strzelecki forests - tall trees grow again New Mountain Ash forest planted on former farmiand.

Reforestation in the Strzelecki Ranges which form the ., southern rim of Victoria's Latrobe Valley is a major project being carried out by the Forests Commission of Victoria and AP.M. Forests Pty. Ltd. Pioneer settlers cleared most of the steep slopes of the ranges for agriculture during the latter part of the nineteenth century. ()_,er two generations many of the settlers moved on to more suitable land and the farms gradually reverted to scrub, bracken and noxious weeds.

Today the Forests Commission and AP.M. Forests are replanting the area with trees. To date the company has established about 5CXX) hectares each of eucalypt and pine plantations and is continuing to plant additional areas every year.

AUSTRALIAN PAPER MA UFACTURERS LIMITED

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FEDERAL SECRETARY: P. Hughes, Box A232 P.O. Sydney South, 2000.

FEDERAL TREASURER: J. H. Greer, C l - Melbourne & M.B.W., 625 Lt. Co lli ns St., Melbo urne, 3000.

BRA NCH SECRETARIES: Canberra, A.C.T. D. Butters, C l - Dept. of Hous ing & Construction Philli p, A.C.T., 2606 New South Wales: P.J. Mi tchell, C l - Envirotech Australia Pty . Ltd., .P .O. Box 220, Artarmon, 2064.

Vict oria: R. Povey, C l - S.R. & W .S. Commission, 590 Orrong Rd., Armadale, 3143.

Queens land: A. Pett igrew , P. O. Box 129, Bri sbane Markets, 4106.

Sou t h Australi a: A. Glatz, C l - Engineering & Water Suppl y Dept.

Vi ctoria Sq uare, Ad elaide, 5000 .

Western Australia: R.J. Fimmel , P.O. Box 356, West Perth, 6005.

Tasman ia: P.E. Spratt, C l - Fowler, England & Newton, 132 Davey St., Hobart, 7000.

North ern Territory: N.R. Allen, 634 Johns Place, Ni ghtcl iff, Darwin , 5792.

THIS ISSUE Th ank you to t he Victorian Branch for you r con tri bu t ion s to this issue.

EDITORIAL E¡N ERGETIC ECOLOGY "Water is the only really big source of energy that can be counted as income and not capital".

Charles Darwin .

The raising of environmental consciousness during the last decade has meant the end of the so-called expert dispensing technical expertise and the vast majority content to accept his decisions and get on with their own private lives .

An accelerated rate of development in all areas of human knowledge has produced large numbers of people capable of understanding environmental problems and making a substantial contribution to decision making processes. • Those people with a more than average interest in the w ell-being of future generations can be a thorn in the side of the scientific specialist.

However it must be borne in mind that this involvement has progressed hand in hand with scientific specialization so deep that it must be controlled to a narrow front.

The amateur expert can make a significant contribution to the community by publicising technological development and presenting facts to the community. We may have learnt to handle water, but as yet we are infants in the handling of amateur experts. Nowhere was this more evident than during the recent petrol strike in Victoria.

Groups interested in the conservation of energy rushed into print advocating everything from solar heating to bicycle tracks. There was a noticeable dearth of comment on the advantages of sea, river and canal transport, or the decentralization of industry to areas close to sources of cheaper hydro-electric power (including New Zealand) or to areas where water can be used as a transportation medium.

Perhaps our amateur experts would be better employed in realizing that water can never be replaced as a resource or source of energy, and as such it must be skilfully collected, used efficiently, and above all neither neglected nor wasted. Even things we take so much for granted require water for the production. For example a gallon of petrol takes 7 gallons of water to produce, one newspaper takes nearly four gallons, a 2 lb. loaf of bread 562 gallons and a half pound block of butter 1200 gallons.

It is shortsighted in the extreme to restrain the funding for developments in the science and technology of the efficient use and reuse of water. Any pause in technological development at this or any stage is likely to result in a backlog of work so acute that the conservation of this resource will be placed in jeopardy .

If recruitment in areas of water management falls away the loss of technical expertise will have repercussions for generations . In both the energy and resource crises there are obvious credibility gaps, inherited from the past, which must be bridged by well-informed public discussion by both technical and amateur experts .

Barrie Murphy, Hon. Editor, "Water".

A.W.W.A. MEMBERSHIP Requests for Appllcatlon Forms for Membership of the Association shou Id be addressed to the appropriate Branch Secretary.

Membership is in four categories : 1. Member-qualifications suitable for membership In the Inst . of Engineers, or other suitable professional bodies.

2. Associate-experience in the W. & W.W. Industry, without formal qualifications .

3. Student.

4. Sustaining Member-an orgapisation involved in the W. & W. W. Industry wishing to sustain the Association .

5

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ASSOCIATION NEWS

A special international conference on land treatment, under the auspices of the I.A.W.P.R., has been proposed for October 1978 following on the success of the Conference visits to the Melbourne Board of Works last October. It will centre on Werribee.

Federal Council has collated the views of the Branches and prepared a submission to the Senate Committee of Enquiry on National Resources in respect to the planning and management of our water resources .

FEDERAL COUNCIL A meeting was held in May. The following items from the meeting will be of interest to members generally.

It was decided that Association membership fees would remain unchanged for the coming year. This · does not bind any of the Branches in regard to any special levies.

AWWA members of ten years standing who have retired from full-time employment or practice may apply to their Branch to continue membership at half-fees .

Guidelines have been drafted to help Branches in the award of honorary life memberships and service plaques. The Service Plaque can be awarded to a member or non-member in recognition of distinguished service in the areas of interest of the Association. The service must be of outstanding order, and may be either technical, administrative or organising , or a contribution of significant order to the community in the fields of water or wastewater.

Honorary Life Membership is to be made to a member only for significant and productive service of outstanding order, to the Association itself.

Awards should be limited in number and should not be bestowed lightly. It is emphasised that length of service, as such, does not constitute sufficient grounds .

There has been correspondence between the Association and the Water Pollution Control Federation in regard to a proposed Engineer-Scientist Exchange Scheme. It is hoped that, through the auspices of the two organisations, a couple of jobexchanges across the Pacific could be organised each year, between engineers or scientists of at least 5 years experience. Obviously there are many diff ic ulties to be ironed out in regard to relative remum,,ation , etc. but both sides are keen to establish a working arrangement.

Mr. R. H. Edwards has been nominated by the Association to serve on a committee of the Standards Association of Australia to review AS881 .

The locations of our Biennial Conference have been confirmed as Queensland for 1979 (as reported last issue) and West Australia for 1981.

6

CANBERRA The Canberra Branch meeting held on 3rd May was addressed by Dr. Ron Rosich who is a Senior Lecturer in Environmental Chemistry . Dr. Rosich spoke of his experiences and observations when he recently spent six months at the Swiss Federal Institute for Water Resources and Water Pollution Control at Dubendorf and six months at the Environmental Research Laboratory Duluth, Minnesota, U.S.A. Chris Settle, this year's Branch President , recently left Canberra after many years of contributing to the activities of the Association and all members wish her well. Charles Speldewinde has taken over the President's duties .

The Annual Social Night was held on 27 May - this year at the Hibiscus Theatre Restaurant.

Planning for the Federal Convention is running smoothly and it is hoped to see many members in Canberra in September.

QUEENSLAND The main Queensland news centres around two successful symposium held in recent months. The first "Symposium 77" held on 28th April, 1977, attracted over 100 delegates and dealt with the water and wastewater problems of Industrial and Urban Development.

Members will be familiar with the news of a recent incidence of a Cholera infection of a woman living in Beenleigh apparently resulting from consumption ot town water contaminated with Cholera Vibrio . This incidence inspired a second Symposium entitled "Water Born Diseases in Public Water Supply" which was held on 9th June and attracted some 80 delegates. The following papers were presented and sparked a spirited discussion.

Mr. P. Wood Lecturer Q.I.T . : "Waterborne Diseases".

Dr. D'Arcy Kelly Health Officer - Dept. of Health & Welfare : "Monitoring of Health Standards".

Mr. K. P. Murphy Exec. Engineer Water Supply Section D.L.G. : "Town Water Supplies".

Mr. B. P. O'Connell Chief Engineer & Manager - Dept. of Water Supply and Sewerage - Brisbane City Council: "Major City Water Supplies" .

Dr. D. Brady PhD Senior Lecturer • University of Queensland: Summary.

Copies of papers of each symposium may be obtained by writing to the ~

JOURNAL SUBSCRIPTIONS AUSTRALIAN WATER & WASTEWATER ASSOCIATION JOURNAL I enclose herewith the sum of $ ............ (Australian) as

prepayment for supply of the following issues of 'WATER'.

June D Sept. D Dec. D 197March D Note: All subscriptions conclude with the December issue, renewals are due by the end of February for a full year's subscription. Price, including surface mail to all countries, is $1.00 (Aust.) each issue, made payable to the A.W.W.A. 'WATER'.

Name ..... .... ..... .............................................................. .

Address .. ....................................................................... .

········································································· ········· ··· Mail this form to: Subscriptions Manager, F. R. Bishop, c/- Camp, Scott & Furphy

390 St. Kllda Road, Melbourne, 3004.

fo llowing address and enclosing $5.00 for each set of papers.

A.W .W.A. P.O. Box 129, Brisbane Markets, a. 4105.

SOUTH AUSTRALIA A combined meeting between the A.W.W.A. and the Clean Air Society of Austra lia and New Zealand was held on 18th May 1977. The guest speaker was Dr. B. T. Commins, Director, Water Research Station, Medmenham Laboratories U.K., and his subject was "Air, Water and Health".

Dr. Commins spent 20 years on air pollution work in Eng land before joining the Water Research Station.

Dr. Commins' talk ranged over chemical and particle contaminants in air and he also spoke on air sampling methods which should, he said, be done in terms of population exposure.

Ideally, samples should be taken at breathing height and be personally taken, but this is impractical. Since the decline in domestic heating by coal fires in Eng land there has been a significant reduction in air pollution. In former days of coal fire heating, research indicated just as high air contaminant load inside as outside domestic dwellings which particularly adversely affected the health of young and old people.

With regard to water, Dr. Commins said that lead was important in England because of lead piping, but there were difficulties in measuring the lead ing est ion rate of the population.

Composite sampling was necessary.

Cardiovascu lar disease was less common with hard than with soft water.

WEST AUSTRALIA The Branch has had three most successfu l technical meetings to date in 1977, these being :An inspection and demonstration of Wastewater Laboratory equipment and analytical techniques at the M.W.B. Laboratory, Subiaco - February 1977.

"Clean up the River Thames", a paper

by Mr Co lin Porter, B.Sc . M.I.E. Au$!., M.A .W.W .A., Assistant Director, Department of Conservation and Env ironm ent, W.A. - April 18, 1977.

"Bugs and Bunkum the truth behind the tests in water Bacteriology ." A paper by Dr. Richard Lugg, B.Sc. M.B .B.S., M.P.H. M.A.W .W .A. Public Health Department, W.A. June 29, 1977.

The Annual General Meeting will be held on Monday August 15th and negotiations are underway for an overseas speaker for this important occasion.

The Committee has had a major drive on obtaining Sustaining Members which was considered an essential step to build up the strength of what is still a very small branch . We are delighted with the response and have recently added 7 new members to our original Sustaining Member, the M.W.B. These new members are Humes, Vinidex, G. B. Hill, James Hardie, D. J. Dwyer, Degremont-M.I.S.-Warman and H. L. Brisbane and Wunderlich.

The Committee has appointed its State President and Federal Councillor Mr. Don Montgomery as Chairman of t he 9th Convention Committee to be held in Perth in 1981. The Vice Chairman will be Mr. Barry Sanders, former Secretary /Treasurer and Federal Councillor for the Branch .

VICTORIA Three meetings have been held since I made the last report ..

Mr. S.Y. Ip, C.S.I.R.O. , addressed the April meeting on recent ¡ development work at the Physicochem icai pilot plant at Lower Plenty.

Mr. lp's extensive knowledge on this subject was evident from his talk.

The interest in new developments in wastewater treatment was maintained at the May meeting when Mr. David Van Dort expla in ed the deep shaft effluent treatment process .

A joint meeting of the A.W.W.A. and the Victorian Branch, Polymer Group of the Royal Australian Chemical Institute was arranged for the June meeting. At this meeting Dr. Russell Smith (C.S . I . R. O . ) spoke on "Reverse osmosis - problems and promises" and Mr. Peter Gebbie followed with a talk on "Wastewater treatment using ultra-filtration" . Dr. Smith's use of a piece of crumpet to illustrate a typical R-O membrane was most interesting.

Mr. W. J. Robertson and Mr. D. A. Wimpole, both of the M .M.B.W., have agreed to face the masses at the July meeting and explain the new trade waste policy for Melbourne. It is hoped that the audience will have an opportunity to express their opinion of the proposed policy.

Fo llowing the success of the first two weekend conferences (Lorne 1975 and Cowes 1976) a third conference is being organ ized for October 21st-23rd, 1977.

The location this year is Thornton and the theme wi ll be "Inland Victorian Waters" . Planning is already well advanced and more details will be re leased in the near future. For those of you who fear that a weekend conference cou ld be too much like hard work, arrangements are in hand to try to organize tours of Lake Ei ldon, Snob's Creek Hatchery, Frazer National Park and the Jamieson Pub! Mr. Lang's comprehensive report on "The re-use of Wastewater" has

recently been published . A limited number of copies are available to libraries (contact Mr. M. A. Smith for further information) .

NEW SOUTH WALES The Regional Conference held at Bowrai on the week-end commencing 18th March was voted a success by ail those who attended . Mr. Ken Aubrey, Chairman of the Sub-Committee , reported that 48 registrants and their ladies attended. He suggested that we should promote the golf day very energetically next year as the trophies provided by the sustainin g members were well worth competing for.

The technical papers were of a high standard and were enjoyed by the delegates .

78 conferences and their ladies sat down to dinner on the Saturday night in what was described as a "cosy" atmosphere . After dinner, some of the brighter sparks danced until early in the morning.

The following Sunday, 23 cars participated in the tour of the Shoal haven Scheme Works. A barbecue was held to close the Conference at Kangaroo Valley .

27th July: "Air Pollution Control for Coal Handling Facilities" by E. M. West of Planner West & Partners Pty. Ltd .

18th July: "Computers as Tools in Water Pollution Control Decision Making" by Prof. R. G. H. Prince, Head of Dept . of Chemical Engineering & Dean of Faculty of Engineering, University of Sydney.

Presentation of Thistlethwaite Memorial Prize to winner - Mr. J. A. Munroe.

16th September: Annual Dinner at North Sydney Club . After dinner speech by Mr. A. J. Carmichael, President, Hunter District Water Board .

12th October: Film Night .

16th November: Speaker and Paper to be advised .

1st December: Christmas Party, 7 p.m. at North Sydney Leagues Club.

NEWCASTLE REGION An interesting programme of meetings and excursions has been arranged for 1977 and we look forward to meeting you on these occasions.

17th July: Family Day - Halton .

17th August : 33rd General Meeting Joint meeting with institution of Engineers . Speaker Dr. A. Pattison, Rainfall and Runoff .

19th September: Tenth Annual General Meeting. Speaker, Mr. W . Johnson .

10th October: 34th General Meeting .

Speaker , Mr. D. Anderson . Some Water Supply Dams and Their Problems.

13th November: Family Day .

7

CADMIUM AND LEAD IN PORT PHILLIP BAY MUSSELS

by V. Talbot, M.Sc. and R. J. Magee, D.Sc. Chemistry Department, La Trobe University, Bundoora, Victoria 3083.

SUMMARY

This paper reports the levels of cadmium and lead found In the trace metal indicator mussel, Mytilus Edu/is, in Port Phillip and Corio Bays. It describes their relative toxicities and implies that in 1975 the littoral waters · and sediments of both bays had undesirably high quantities of both metals.

Some analyses on oysters and scallops are also reported .

INTRODUCTION

While some metals, which are not essential to life, are excreted by marine organisms, there are those which the organisms only partly excrete. Two of these are cadmium and lead. The toxic effects of these metals have been reviewed 1, 2 and are currently receiving much attention in Victoria3.

A recent survey of trace metals in sediments of the bay has been reported by this laboratory4. The results have been in part conflrmed5 , 6. The present paper reports an extension of this earlier work.

EXPERIMENT AL Sample collectlon

Samp les of the mussel Mytllus edu/1s were collected in June 1975 from 22 sites round the shores of Port Phillip and Corio Bays, Victoria, as shown In Fig . 1. The bulk of the samples were collected by diving from locations which were continuously submerged. A few samp les were taken from the intertidal zone, from piers in Corio Bay. Oysters [Ostreidae Angas/] were co llected from Corio Bay. Scallops were purchased from various commercial distributors but no record of their origin was obtained other than that they had been harvested in Port Phi llip Bay. Analytlcal procedure

From each location, twenty mussels of approx imately 5.5 cm length were divided into two sets . The total soft portions of one set were dried at so·c for 24 hrs, separately homogenised, then analysed . The others were 8

dissected and the various tissues prepared In the same way in order to determine the sites where cadmium and lead were concentrated 7 . Results are presented as the mean values and standard deviations of each set .

Oysters from each location were homogenised Into a single sample; scallops were dissected and analysed separately . The samples were analysed by adding 0.1 g dried homogenate to 1o ml of doubly-distilled 7M nitric acid and evaporating to dryness, then reoxidising with 8 ml 3.5M nitric acid and 2 ml perch lo rlc acid. The dry residues were then disso lved In 1M nitric acid and analysed using a Varian Techtron AAS atomic absorption spectrophotometer.

Blanks were run twice to check background corrections on reagents.

Preliminary checks were made in conjunction with other analysts to determine variances in the technique .

The National Health and Medical Research CounciI12 and others13 stil l adhere to the wet weight system . To convert from wet weight results to dry weight results it is necessary to multiply by a rough factor of 4.5. This approximate factor takes into account the variation of percentage of water in the mussels throughout the year.

Fig . 1 gives the sampling locations for mussels and oysters in Port Phillip and Corio Bays.

Fig . 2 summarises the results of sim ple toxicity tests on Mytilus edu lis, at varying concentrations of cadmium and lead salts added to seawater at a pH 8.1, temperature 14-17°C and an oxygen range of 6-9 ppm.

Fig . 3 summarises the level of metals found in the dead organisms during the above toxicity tests at the time when half the population had succumbed .

Blologlcal experiment

1 . Toxicity of shellfls'h to humans Table 5 lists the limits set by the Austra lian National Health and Medical Research Council for metals in foodstuffs. Ttle W.H.O. standards are not tabulated, but maximum daily intakes of certain trace metals are recommended, from which trace metal levels in foodstuff can be calculated14,15

DISCUSSION

Toxicity determinations in mussels were performed In the usual manner using various amounts of cadmium and lead chloride salts in seawater.

Comp li cations due to other ions were not Introduced .

An experiment using A.C. and D.C. to stimulate the anterior byssus retractor muscle of Mytilus was performed according to procedure published by other authorsB,9,10,11 Both uncontaminated and heavily contaminated specimens were tested .

RESULTS

Table 1a gives the mean values and standard deviations for each set of ten determinations for cadmium levels in the mussel samples collected from the table 1 b the sea floor and corresponding lead levels.

Table 2a and 2b give comparable values for mussels collected from inter-tidal zones in Corio Bay. Table 3 gives values for both metals found in oysters collected in Corio Bay .

Table 4 gives values for cadmium in the edib le portions of scallops harvested from Port Phi llip Bay .

The results are all quoted as ppm of metal on dried tissue weight.

(a) Cadmium The cadmium levels in mussels from 15 out of 22 locations sampled indicate that the littoral waters of Port Phillip • and Corio Bays, in June 1975, could be regarded as heavily polluted as a food source (Table 1a) . Even those locations not so polluted were , however, close to it . If, on the other hand, W.H .O. standards and not N . H . M.R.C. standards for food are used, al l locations may be considered as being polluted. Two anomalies appear to exist in the water, in Corio Bay and in the inner part of Point Richard Channel, and to a lesser extent at the mouth of the Yarra River. Errat ic results occur in these estuaries and industrialised areas because of dredging, currents, etc ., which influence musse l migration .

Further, sudden chemical changes in water affect the cadmium levels present .13

Tables 1a, 1b Levels of metal in Mussels from Port Phillip and Corio Bays (ppm on dried tissue, mean values and standard deviations) Lead

Cadmium Loe. 1 2 3 4

Foot 16.8 8.9 16.3 6. 7 28 .6 17.9 8.9 4.8

5

6 7

8 9

10 11 12 13 .

14 15 16 17 18 19 20 21 22

4 .6 2.6 17.8 9. 7 4.9 2.3 3.6 2.8 2.2 1.8 3.7 2.3 4.6 3.2 4.7 2.7 5.2 2.3 4.6 1.9 12.6 4.3 6.7 2.8 7.2 2.9 3.9 3.1 4.9 2.9 3.2 2.2 6 .9 3.8 3 .3 2.4

GIiis 73 .2 29.4 32.8 14.9 98.4 38.7 75.3 31 .2 56.7 15.6 70 .9 22.8 33.2 12.4 21 .6 8.9 14.4 6.8 21 .6 9.8 16.6 7.7 39.7 12.8 16.7 3.9 21 .8 4.7 17.6 8. 1 14.4 3.9 12.4 3.3 27 .3 12.4 11 .8 5.6 18.7 5.3 10.4 5.7 8.8 4.1

Stomach 76 .7 31 .2 28.1 10.6 93.8 19.9 68.3 24.6 32.4 10.3 78 .3 27.4 14.3 6.4 8.3 3.3 7.2 2.5 11 .6 3.8 17.9

Muscle 32.3 9.8 27.8 12. 7 59.8 14.6 21 .6 8. 7 33.7 8.9 36.4 17.2 8 .7 4.7 7.3 4.2 8.3 4.5

6.6 3.3 14.3 9. 1 31 .1 9.7 11.9 4.3 13.7 4.6 12.3 4.8 12.7 4.3 9.6 2.6 11 .3 8.4 10.3 4. 7 17.3 4.9 8.9 4.3 3. 9 2.2

8.4

35.8 13.9 18.7 4.9 26.4 6.9 14.7 6.3 18.6 6.4 11.6 3.8 24.9 12.6 12.9 6.8 16.7 4.8 23.9 6.8 9.3 2.9

Mantle 26.7 10.3 16.3 9.8 49.3 24.4 12.4 7.3 8.4 5.1 29 .8 16.3 7.8 4.2 6.8 4.7 6.9 3.2 6.4 2.9 10.9 6.2 16.6 8.6 6.4 2.2 6.9 2.4 6.2 2.7 5.6 2.8 6 .3 2. 1 7.3 3.8 4 .3 2.5 5.5 2.6 5.7 3.8 2.6 1.2

Shell 10.5 3.3 3 .5 1.9 10.9 3.8 7.3 2.2 9 .3 1.8 11.4 3.1 6 .9 2.5 3 .9 1.2 2.8 0.9 3.3 1.2 2.8 1. 1 4.9 2.2 2.2 0.7 4.4 2.3 3.6 1.9 2.8 1. 1 3.3 1.9 4.1 1.5 1.9 0.5 1.8 0.6 3 .9 1. 7 2.4 1.8

Bulk 63 .1· 17.8 48 .4· 12.6 88 • 32.3 43 • 14.7 33.s· 18.9 62 .4 .

21 .6 18.3 .

7.2 12.3+ 5.3 8.35.2 17 • 6.4 9 2. 1 24 .a • 6.3 6.64.2 21 • 8.3 10.5+ 5.2 14.8+ 4.9 9.43.7 15_4• 5.7 5.33.9 6 .14.3 17 • 5.8 7.33.9

Loe.

1 2 3 4

5 6 7

8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Foot 6.4 1.3 8.3 2.8 8.2 3.2 7.3 2.2 4.3 2.4 3.7 2.8 4.2 2.8 8.3 4.6 5.1 2. 1 8.3 4.9 7.4 2. 1 3.7 2. 1 4.7 2. 3 5.7 3.2 7.3 4. 1 7.8 3.4 8.3 4.6 6.4 3.3 7.3 2.9 4.9 2. 1 8.4 3.6 6.2 2. 1

GIiis 32.6 13.8 16.3 4.8 14.6 4.8 24.6 10.8 15.9 4. 1 19.4 6.4 18.7 6.8 15.3 3.8 12.4 3.6 11 .2 2. 1 23 .8 6. 7 18.8 3.6 18.7 2.6 26.8 8.4 12.8 5.5 17.8 4. 7 20.6 4.3 18.7 4.5 23 .8 7.6 13.5 5.4 19.1 6.7 14.3 4. 7

Stomach 18.9 9. 7 8.9 4.2 9.6 3. 1 22 .9 8. 1 9.3 4.4

8.9 2.3 9.4 2. 1 12.6 4. 1 11.6 2.9 9.6 3.2 14.3 5.9 16.9 4.7 13.9 4.8 29 .4 9.2 13 .4 5.3 20 .6 4.3 19.3 3.9 17.3 6.8 21 .8 5.8 12.6 4.9 23. 6 5.8 12. 6 3. 4

Shell 27 .4 3.6 24.3 4. 7 27.3 4.3 36.3 5. 1 24.8 15.4 81 12.6 35.8 5.8 18.9 ~ 6.9 37.1 9.6 16.3 5.3 8.7 4.1 33.4 11 .8 36.4 8.6 17.4 5.4 36 7.8 61.7 18.9 53.4 16. 7 46 .0 13.5 29.4 9.9 36.1 12.9 52.0 17.4 26 .1 9.7

Bulk 1s.2· 4.3 10.7+ 2.9 13.3+ 3.7 19.a • 3.9 11.1 + 4.2 18.9.

3.8 17.9· 4. 1 11 .3+ 3. 7 10.3+ 4.2 9.72.8 15_4• 4. 7 15.2· 4.9 1s.a· 5. 1 22_4• 2.8 6.63.4 14.1 + 4.8 17_9• 5.2 15.a· 6.2 18.9· 5.2 13.6+ 4.6 18.9· 7. 2 8.32.9

.,,

exceeds W.H.O. standards.

Borderline.

Under.

+

Muscle 12.3 3.9 10.1 3.4 9 .8 2. 1 15.3 4.2 4 .2 3. 1 10.1 2.9 6.1 2.3 10.3 3.4 8.7 2.9 5.4 3.3 12.1 6.4 8.5 2.9 10.2 3.8 17.8 6. 7 7.7 3.2 13.5 4.6 15.1 4.6 9.4 4.4 14.6 4.8 10.4 5. 1 14.8 3.8 7.2 3.8

Mantle 4.6 3.2 4.6 3.8 8.2 2.9 5.3 2.4 4.1 2.7 8.6 2.4 6.8 2.4 9.1 2.8 8.6 2.7 4.8 2.9 7.4 4.3 7.5 2.7 6 .5 3. 1 14.5 4.9 6.9 2.4 7.8 3.1 8.7 2.8 8.9 4.6 13.7 4.3 7.2 3.8 7.3 2.3 5.4 2. 1

Tables 2a, 2b Levels of meta l in Mussels sampled from the inter-tidal zone of piers in Corio Bay (ppm on dried tissue, mean values/standard deviat ions)

Cadmium Loe. 4

8 10 11

Foot 3.7 1.8 1.8 1.2 4.8 2.3 2.1 1. 7

GIiis 19.9 7.3 6.8 2.6 14 .3 5.4 5.6 3. 1

Stomach 9.8 3.9 3.5 2.1 16.7 6. 1 6 .3 3.2

Muscle 8.1 3. 7 4.2 2.5 10.4 3.9 3.8 2.3

Mantle 7.3 2.8 3.9 1.9 5.9 2. 8 2.4 1.4

Shell 3.9 2.4 2.4 1.8 2.2 1.6 1.7 1.1

Bulk 13.5 4. 7 4.2 2.7 7.7 3.8 2.8 0.9

Mantle 2.2 1.2 2.6 1.4 2.7 1.4 3.1 1.3

Shell 13.4 2.8 12.6 3. 1 11 .9 2.8 11 .4 3. 1

Bulk 4.7 1.4 4.6 2.4 3.7 1.1 3.4 1.4

Lead Loe. 4

Foot 3.4

8

3.1

1. 1

1.4

10 11

2.1 1.5 2.4 0.9

GIiis 4.9 1.4 4.7 2.1 4.8 2. 7 5.1 2.1

Stomach 4.8 1.7 5.1 2.2 4.6 2.2 4.8 1.6

Muscle 2.9 1.3 3.3 1.8 3.9 2.6 3.8 1.6

Q

I('

20

'---- -~-K 1l oni et 1 1: '>

Sampling locations for mussels and oysters In Port Phllllp and Corio Bays.

9

On N.H.M.R.C. standards, the non-industrial area between Sorrento and Mornington might be regarded as a borderline case .

Metal levels in mussels sampled from the intertidal zone of piers are considerably lower than those found in bottom dwellers that are continously submerged. This may be partly due to the accumulation of metals in sediments16 so that mussels on the bottom sh-c>w a greater uptake of cadmium.

A most interesting comparison Is that between the uptake In oysters and mussels. The results in Table 3 clearly indicate that oysters have a greater uptake of cadmium, and those from Corio Bay were particularly toxic.

Table 4 indicates that the cadmium levels in the edible portion of scallops from Port Phillip Bay are well within the safe limits for food as set down by the W.H.O. However, metals accumulate in _the digestive system of scallops just as happens for many other species.

Inedible portions of scallops from Port Phillip Bay have had as much as 28 ppm cadmium dry weight. (b) Lead This element is present In mussels at levels unacceptable by N.H.M.R.C. standards for food. It appears to be even more widespread than cadmium. although in smaller concentrations.

30 20 10

s 4 3

E

g:

2

u C 0

u

1

I

·S

1

2.,

I

:I:

.,,

j 2

3 4 S

10

20 30 40 SO

100

200

TIME ( DAYS)

L.D. 50 curves for Cd(o) and Pb(x) for the mussel, Mytl/us edulfs at a pH of 8.1 and a temp. range of 14-17°C.

30 20

Table 3

Levels of Cd and Pb in Oysters from Corio Bay (ppm on dried tissue, mean values and standard deviations) Location 2

3 6

Cd

35.5 8.9 174.3 39.5 64.9 14. 7

Pb 5.4 2.7 8.0 2.6 4.0 1.8

10

s E a. a.

u

C 0

u

E, .,

:I:

Table4

Levels of cadmium in the edible portion of Scallops collected in 1975 from Port Phillip Bay (ppm on dried tissue, mean values and standard deviations) Source A B

C D

E

F G H

J

10

Muscle 1.92 .94 .97 .48 1.8

Gonads 3.21 1.73 4.82

.89

8.26

2.58 .78 2.76 . 77 .86 .56 1.7 .35 2.2 1.02 .92 .81 1.66 1.28

4.12

6.89

s

l -1 L , . . - - - - - - L . . , : - - - - - - - - - - - 1 . : - - - ~ - - - - - - ; ; - 5 - - - - - 4 10 2 103 104 2x10 10 Cone . of Metal in Myt1lus after half t he population had d ied, ppm .

Cd(o) and Pb(x) levels detected In mussels on completlon of the L.D. 50 experiment at various concentrations .

8.64 2.84

4.82 4. 10

5.43 3.81 8.38 6.38

10.4 • 17.9 4.92 3.89 7.89 4. 19

Table 5

N.H.M.R.C. standards for metals in food .

Metal Zi nc

Cadmium Manganese

Copper lead

ppm (wet weight) 1000 2.0 100.0 30.0 2.0

approx. ppm on dried tissue 4500 9 450 135 9

It may be concluded that there is more lead pollution on the east coast of the bay. The sources may well be widespread, but water movement durin g ebb tide and flood tide flushes out the Yarra estuary in a direction parallel to the east coast, thus distributing the po ll ution17. Other sou rces of this metal appear to be the Werribee River area and t he Corio Bay area. It is noteworthy that musse ls have a greater uptake of this metal than oysters, even though mussels have no known biological need for this toxic metal.

2. Toxicity to the shell-fish In spite of lead being considered a very toxic element, its short-term effect on mussels is much less severe than that of calcium. Fig . 2 gives the results of simple tox icity tests, plotting the L.D.50 for various concentrations of cadm ium and lead salts added to seawater. It shows that 1.5 ppm of cadmium has a more toxic effect on mussels than 30 ppm of lead . However, the concentrat ions of the metals in this toxicity experiment were many orders of magnitude higher than any found in the waters of either Corio or Port Phillip Bay, the latter being around 0.0005 ppm. Nonetheless, the available concentrations in the sediments may be much higher. Fig. 3 summarises the leve ls of meta ls found in the dead mussels when half of the populat ion in the toxicity had succumbed experiments .

Levels of lead up to 16,000 ppm (on dried tissue weight) were found in organi sms which surv ived for 200 days.

It does not seem likely that the levels fo und in the mussels sampled from the Bays pose a short-term hazard for the organisms themselves .

Levels of cadmium ranged from 600 ppm to 2,300 ppm. It has been reported previously 20 that mussels taken from Corio Bay in 1974, from locations c lose to sources of pollution , contained more t han 200 ppm of cadm ium , and yet were stil l ostensibly healthy .

Noel-Lam bot 21 reported that in 36 days , mussels accumulated 80 ppm wet weight (or approx. 360 ppm on dried t issue) of cadmium from seawater co nta inin g 0.13 ppm and 2.8 ppm (12 .6 ppm on dried tissue) in 90 days from 0.005 ppm .

Thus the leve ls found in the samp les analysed in th is investigation do not necessarily pose a hazard for the organisms themselves.

It has been shown by Noe l-Lambot, and conf irmed by the authors, that metal lo-thionein is synthes ised by the organism in response to cadmium uptake, However, if the uptake is abrupt , and the organism is unab le to sy nth es ise the metal-binding-protein (M -B-P) quickly enoug h, t hen death may ensue. One must take into

account the balance of accumulation, i.e., uptake and excretion, as well as the t ime factor.

Unpublished work by the authors show that excretion from contaminated mussels is initially rapid, but decreases in rate with time; hence the assignment of one discrete biological half-life for cadmium in mussels is erroneous.

Protein fractionation of mussel tissue extracted on a sephadex column by this laboratory shows that cadmium is bound to three discrete organic fractions each having its own rate of uptake and excretion.

Further unpublished work has shown that lead, when added to seawater in the nitrate form, rather the chloride form, is more toxic. It can be concluded that our simp le L.D.50 model for metal salts in seawater is only a first approx imation and that ideally toxicity has to be associated with metal speciation .

A.c and d.c. st imulation of the anterior byssus retractor muscle of Mytilus indicated that the present levels of lead and cadmium in the mussels in Port Phil lip Bay do not pose a threat.

However, laboratory mussels contaminated with lead especially showed that the catch mechanism in the muscle did not release abrupt ly, hence not all owing the musse l to open Its valves very quick ly. This observation has been drawn on a stat ist ical basis after observing a large number of mussels.

used as a monitoring tool to keep a watch on lead. Such an a.,pp lication can enable one to differentiate between the levels of lead in the environment before and after domestic and industrial development. More subtle measurements can be carried out, as in this laboratory, where the calcite, aragonite and organic matrix of the shell are separately analysed. Since the growth of the shel l matrices can be dated, so also can the variat ion of lead leve ls in the environment in which it grew.

Sim ilar work has been reported from Sweden! 9 CONCLUSIONS Cadmium and lead le els found in shel lfish in 1975 indicate that these metals were present in the littoral waters and sed iments of Port Phil 1ip and Corio Bay in quantities that contaminated the food chain . Mussels and oysters were rendered unsafe for human consumption, though the edib le port ions of scallops were within limits set by N.H.M.R.C. Cadmium is more toxic to mussels than lead when admin istered abruptly.

However, from small er concentrations, the organism can accumu late large concentrat ion s of both metals, the cadmium as a protein complex, principal ly metallo-thionein, the lead largely in the inorganic PbCO3 form.

Thus, ne ither of the metals pose a short term lethal threat to the musse ls themse lves . Analyses of lead in mussel shell s may give a historical record of po ll ution.

3. The shells of Mytl/us as a pollution indicator

Trace metals usual ly accumu late in the digestive system and grills of mussels7 . One anomaly is that higher leve ls of lead were found in the inorganic shel l material than in some organs of the soft body . Calc iu m and lead both form divalent ions; a pH model for spec iation of Pb in seawater at a pH of 8.1 const ru cted from ava il ab le and estimated thermodynamic stabi li ty constants and activity coeff icients in dicate that 87% of Pb is present in the PbCO 3 form18. The same workers predicted that Cd, Zn and Cu wou ld be in the CdC 2 , ZN (OH) 2 and Cu(OH) 2 forms, respective ly . Unpubli shed work by this laboratory has shown that lead accumu lates in the cytop lasmic solutions of cell s of the mussel Mytilus edulis as the inorganic PbCO3 species. Further work has shown that the fractional turnover of lead is very slow compared with cadm ium which is predominantly bound to protein fractions . Hence it is difficult to get lead levels in mussels to fal I even if the sources of pollution are removed.

Computed analyses on lead levels in th e total shells of mussels have indicated that the accumulat ion of lead in musse l she ll s can be successfu lly

REFERENCES 1. Flick, D. F., Kraybill, H. F. and Dimitroff, J. M., Envir. Res. 4, 71 -85 (1971) .

2. Clayton, B. E., B~ Med . Bu ll ., 31, 238-240 (1975).

3. Talbot, V. W., Magee, R. J. and Hussain, M., Mar. Po ll . Bu ll ., 7, 84-85 (1976).

4. Talbot, V. W., Magee, R. J. and Hussain , M., Mar. Po ll. Bull., 7, 5J-55 (1976).

5. Anon. Env ironmental Protect ion Aut hority.

Report No. 16/76.

6. French, H. T. and Thistlethwaite, P. J., Proc.

Roy Aust. Chem . In st., 43, 73 (1976) .

7. Brooks, R. R. and Rumsby , M. G., Lim .

Oceanog ., 10, 521-7 (1965).

8. Sandow, A. and Isaacson, A., Journ . of Gen. Physio l. , 49, 937 (1966) .

9. Lowy, J. and Millman, B. M., Phil . Trans. R. Soc . B., 246, 105-148 (1963) .

10. Takahaski, K., Annotnes Zool. Jap., 33, 67-84 (1960).

11 . Kerkut , G. A., "Exp. in Physlo. & Biol." Vol. 1, Acad . Press . Lond. & N.Y. (1968).

12. Ecos. C.S. I. R.O. Envir. Res., 1, 3-10 (1974) .

13. Fulkerson, W. and Geoller, H. E., (Eds.), Cadmium - the d issipated element. Rep. No. ORNL: NSF-EP-21. Oakridge Nat. Lab. N.T.I.S., pp. 46-55, pp. 371 -394 (1973).

14. W.H .O. Tech. Rep . Series, No. 373, 15 (1967).

15. W.H .O. Conference Report, Geneva 1975.

16. Bloom, H., " Heavy Metals in the Derwent Estuary", Univ. of Tasman . Report (1975).

17. Melb. Metro. Board Works , "Envir. Study of Port Phi llip Bay". Rep. Phase one (1973) .

18. Zirino, A. and Yamamoto , S., Limnol Oceanogr., 17, 661-671 (1972) .

19. Sturesson, U., Ambio, 5, 5-6, 1976.

20. Vic. Parl. Hansards, 27 , 7881 (1975).

21. Noel-Lambot, F. , Experientia, 32, 3, pp. 32436 (1976).

11

The Dartmouth Dam Environmental Survey Compiled by:

a. Farmar-Bowers, B.Sc.(Hons.), Dip.Ag.Econ., Dip.Bus.Stud.M.A. Environmental Studies Officer, State Rivers and Water Supply Commission of Victoria

INTRODUCTION

Dartmouth Dam, a central-core rockfill embankment 180 m~tres (m) high and with a volume of 14 million cubic metres (m3), will impound a reservoir of 4 million megalitres (Ml) capacity on the Mitta Mitta River In north-eastern Victoria. It will be Australia's highest dam to date.

The Mitta Mitta River rises near Mt. Bogong, the highest peak in Victoria and flows generally north-westerly until it enters the existing River Murray storage, Lake Hume, near Tallangatta. In the vicinity of the dam site, the river is incised below the earlier mature topography in a V-shaped gorge with a valley width at river level mostly between 15 and 30m . A locality map of the area is shown in Figure 1.

The three main rock formations in the project area are Snowy River volcanics, granite and un-named metamorphic rocks probably of Devonian , Silurian and Ordovician ages respectively. The rock type in the gorge section of the Mitta Mitta River in which the dam is located is granitic gneiss.

Granite occurs both upstream and downstream of this section, where, due to the greater tendency of granite to chemical weathering, the valley has been widened .

The dam and associated works are being constructed for the River Murray Commission (AMC) by the State Rivers and Water Supp ly Commission of Victoria (SRWSC). New South Wales, South Australia, Victoria and the Commonwealth of Australia are partners in the project which will supply each of the riparian States with additional water for irrigation and town supplies. This will include water pumped to the city of Adelaide, situated 2,200 kilometres (km) downstream . The SRWSC, as the Constructing Authority, has engaged the Snowy Mountains Engineering Corporation as its design consu ltant .

A hydroelectric power station will be located at the downstream toe of the dam, and discharges from this station will be regulated by a pondage formed by a concrete dam across the river downstream of the main dam . These works wi ll be desigrred and constructed by the State Electricity Commission of Victoria (SECV) . The power station will be operated in accordance with an agreement between the SECV, SRWSC and AMC, covering the release of water for power generation .

Excavation and lining of the low level and high level tunnels is basically complete . Placing of the main embankment and excavation of the spillway-cascade is well advanced.

Concurrently with this major dam construction programme environmental aspects have been progressively examined and analysed.

investigation, design and construction of the Dartmouth Dam .

The purpose of the survey was to establish the existing physical and biological conditions in the area so as to provide a base from which future changes could be measured and , in addition, to provide information on which future operational procedures could be planned so as to minimise adverse environmental and ecological effects of the dam.

It was also deemed necessary for both Commissions to be in a position to refute any mis-statements on the ecology which might be made from time to time and this is only possible if factual results from suitable research are available .

Under the chairmanship of the Chief Engineer, Major Work s, of the Water Commission, a steering committee was set up comprising senior representatives from both the Forests Commission and Fisheries and Wildlife Division. At

...

I

ENVIRONMENTAL SURVEY

On 27th June, 1972, the River Murray Commission agreed that an ecological survey of the Dartmouth area and the Mitta Mitta River downstream of the proposed damsite was a necessary part of the implementation of the Dartmouth Dam Project.

The State Rivers and Water Supply Commission as the constructing authority under the River Murray Waters Agreement, was authorised to conduct the survey, the cost of which was to be regarded as part of the cost of the 12

All dimensions ore in metres

DARTMOUTH DAM GENERAL ARRANGEMENT

Mitta Mitta River at Mouth of Dart River.

its .first meeting in August 1972, tentative terms of reference for the study were drawn up.

The participating organisations are the Forests Commission, Fisheries and Wildlife Division of the Ministry of Conservation, the National Museum, the Conservation Council of Victoria, the Vermin and Noxious Weeds Destruction Board of the Lands Department, the State Electricity Commission of Victoria (SECV) and the Water Commission.

The pre-impoundment phase of the environmental survey is complete and the estimated cost about $350,000. Certain significant ecological parameters will be monitored for some years after completion of the dam.

potential ot the new lake and assist in Its early management.

It is also important to know the relative area's of deep and shallow water in the lake and the fish species already ¡ present, for these will make the earliest contribution to its future fish population .

The downstream survey will provide a basis on which to assess the effect of construction of the dam, and later Its discharge operations, on the fish population along the Mitta Mitta River downstream as far as Lake Hume, especially those which use the upper or lower reaches for spawning .

The downstream tributaries have also been surveyed.

Three distinct fish habitats emerged from the study of the M Itta M Itta.

1. Between Lake Hume and the damsite, redfin are numerous and there are some brown trout. There is an established population of Murray cod in the section below Mitta Mitta township but above this point they are only of occasional occurrence with a few Macquarie per.ch just below the damsite.

2. Above the damsite there is a significant number of Macquarie perch and a good brown trout population with some blackfish and redfin.

3. Upstream of the reservoir area brown trout are predominant with blackfish present in some sections of the river.

Various tributary streams carry single or mixed populations of brown trout, rainbow trout, blackfish and redfin.

Wildlife Survey - In the area to be inundated a survey of the terrestrial vertebrates was carried out which revealed 24 species of mammals, 24 species of reptiles, 10 of amphibians and 100 species of birds. No rare or unusual animal species have been found.

Both surveys were undertaken by the Fisheries and Wildlife Division of the Ministry-for Conservation.

Invertebrates

Vegetation

In order to assess the impact of the dam on the upstream and downstream plant communities it was essential to determine the characteristics of the existing vegetation and associated soils. Approximately 600 plots were involved In this part of the study, most of which are in the reservoir area .

The vegetation survey is being carried out by the Forest Commission .

High quality aerial photography of ail areas of importance was executed to (i) facilitate the vegetation survey (ii) assist in animal studies and (iii) facilitate detection of downstream erosion patterns and former courses of the stream .

Transect plots across selected downstream lagoons were sampled together with transects across a range of water courses. Permanent plots have been established at and above full supply level in each of the defined plant communities.

These plots will be used for continual observations of the effects of inundation on the vegetation.

As a result of the vegetation survey eight plant communities have been defined by a computer-aided analysis. A total of 430 plant species were identified, eleven of which are of importance or unusual occurrence.

The invertebrates fauna of the Inundation area was the subject of an initial survey by the National Museum in order to compile fauna l lists, identify "key" species and map their distribution to assess changes in the ecosystem caused by the flooding .

The emphasis however was later shifted to the river downstream of the damsite for it is ~ere that significant changes in the aquatic invertebrate population may occur following expected alterations to the temperature and flow regime of the river.

Several sites were chosen for a quantitative survey of the invertebrate animals which spend some part, or all, of their life cycle In water. These include the caddls flies, midges,

Vertebrates Fisheries Survey -

This study was designed to examine the phys ica l and biological characteristics of both the Mitta Mitta River and the future lake as fish habitats and to survey the river for its existing resident fish population and its use by non-resident fish as a spawning ground. Upstream and downstream reaches of the river have been sampled for this purpose.

Information from the upstream river reaches and the tributaries is necessary in order to predict the fishery

Sampling for aquatic invertebrates in a swamp upstream of the damsite.

13

water beetles and many other insects together with snails, mussels, worms and crustaceans.

Results have shown a large and diverse population of these small aquatic animals in the river and its associated bi ll abongs; also in the lagoons of both survey areas. The most important factors influencing their distribution are the nature of the stream bed, whether sand, gravel or mud , and the ve locity of the f low. As many of these animals depend on various precise river conditions to complete their life-cycles , quantitative pre-impoundment data is essential as base- line information on which to base further monitoring studies to assess the impact of the dam on these very sensitive biologica l indicators of river conditions.

Vermin and Noxious Weeds The Vermin and Noxious Weeds Destruction Board conducted three studies.

Fox and Dingo Project - The diet of dingoes or feral dogs and foxes in the reservoir area was investigated by analysis of hair structure in dropped faeces (scats) of these animals. The main food items of dingoes or dogs were wallabies, wombats and great grey kangaroos . In the lower valley region rabbits were t he main food of foxes and in the upper regions native r.odents, dasyurids and possums were more important. Other food consisted of insects , fruit and birds .

A list of mammals in the area was made. The inundation of the reservoir area wil l cause loss of habitat for prey and subsequently predator anima ls. Some foxes and rabbits but not dingoes may be able to re-establish in disturbed areas .

Based on experience in other parts of the State, it is possible that the number of feral cats will increase after completion of the project due to the increase in tourism .

Rabbit Project Based on serum protein , three genetically distinct sub-populations of wild rabbits were found in the Dartmouth region . These have evolved on highly developed farmland and in native forest. There has been differential selection for coat colour (yellow , black and grey) and blood serum allotype. There is no evidence that the construction of the dam will Increase rabbit control problems except in areas which are cleared and grassed .

Weed Project - Blackberry is the main weed problem at Dartmouth because the thickets eliminate other vegetation and prevent access to streams. This weed is extensively spread by foxes and emus.

The frequency of alien plants declined with increasing distance from roads and this was associated with a reduction in l ight.

Wetter plant communit ies were more colonised by alien plants than drier commun ities . A range of alien plants was present and these differed in their ability to spread into the bushland from the disturbed roadside sites. It will be necessary to inspect the roadsides and water line annually for noxious weeds and to spray new infestations with herbicides.

Conservation Although not actively participating in the surveys the Conservation Council of Victoria was inv ited to liaise with the Water Commiss ion in matters relating to the studies.

Contribut ions included investigations of the route of the Dartmouth-Mount Beauty powerline, the environmental aspects of the poss ible re-routing of the Omeo Highway and poss ible river improvement works along the M itta M itta downstream of the Dartmouth .

River Flow Survey The SECV has been involved in an investigation of present and future river flow and river bank stabi lity. Aerial photographs were used and the work has included surveys of banks, soi l types, and comparat ive studies of natural flows with regulated f lows as regards discharge, variab i lity and temperature variat ions .

14

Wa ter Research The Water Research Sect ion of the Water'tommiss ion has und ertaken a groundwater survey and a farm survey of the Mitta Mitta River flats to determine the effects the altered flow regime could have on groundwater levels, pasture growth and general agricultural activities .

The groundwater survey involved periodic monitoring of water levels in groundwater observat ion bores, selected lagoons and the M itta M itta River.

A _confident ial survey of farms was carried out to assess the influence of the existing flow regime of farm management practices and to obtain detailed Information on farm production in the area.

Post- impoundment studies will invo lve monitoring of groundwater levels at selected times .

Water Quality • The Water Commission's laboratories are responsible for regular water quality monitoring over the entire survey period and will also undertake limnological investigations in the new lake from the commencement of impoundment .

Sampling for various physical, chemical and biological parameters commenced in February 1974 in order to establish a base from which comparisons of water quality during and after construction can be made. Turbidity measurements will be highly significant in view of construction operat ions and temperature is pertinent to the future management of a storage which is expected to discharg e water of uniform low temperature unless design modifications are made . Concentrations of iron and manganese , and the plant nutrients nitrogen, phosphorus and sili con may have a sig nificant influence on the water quality of the new lake.

An automatic water qua lity monitoring device has been placed in the Mitta Mitta River below the dam for continous recording of temperature, dissolved oxygen, suspended solids , conductivity, turbid ity and solar radiation.

River Temperature Control of Discharge Temperatures - Predictions are that the 170 m deep Dartmouth Reservoir wil l thermally stratify in the summer with water temperatures of up to 24°C in the upper layers and down to 9°C in the lower layers. The thermocl ine or level of sudden drop ill temperature where the wind induced circulating currents cease to operate is expected to occur at about 20m below the water surface.

As originally designed, the sill of the main outlet , the high level outlet, would be 63m below full supply level , and therefore summer discharges.,could be wel l below normal summer river temperatures . The Commission arranged for a group of limnologists , fisheries and invertebrate bio logists and eng ineers to investigate and report on the ecological effects of such a change. As a result the River Murray Commission agreed that provision should be made in the outlet design for facilities for water temperature control to be instal led at a later date should the eco logica l studies show this is necessary.

This prov ision consists of : (a) Modifying the high level outlet to allow an upward extension with multi-level intakes to be bui lt at a later date. (b) Designing and partial ly instal ling aeration equipment to assist the upper circu lating currents to penetrate the thermocl ine and bri ng warm water from the upper layers to the high level outlet .

A number of destratification installations in the U.S.A. and Europe were in spected before developing the Dartmouth des ign and th is was fo llowed up by hydraulic mode l studies and f ul l sca le fie ld tests on Ei ldon reservoir. The design cons ists of two aerators set into the reservoir bed 180m upstream of the out let and 100m below ful l supply level. It has been estab lished that bubb ling air through the water from these aerators w ill modify the outlet . discharge temperatures.

l

I

1 I

J

LAND CONSERVATION COUNCIL, VICTORIA¡ FINAL RECOMMENDATIONS ON THE MELBOURNE STUDY AREA The Land Conservation Council, Victoria, has published final recommendations for the use of public land within the Melbourne Study Area. This area extends from the vicinity of the Moorabool River In the west, eastwards to a line running through Yallourn, and from Bass Strait northwards to a line through Castlemalne, Seymour and Mansfield .

The Land Conservation Council Is required to make recommendations to the Minister of Conservation with respect to the use of public land throughout the State with a view to providing for the balanced use of such land In Victoria . In publishing Its recommendations for the Melbourne Study Area, the Council has nominated Its assessment of the best use for the public lands and Indicated what it considers to be the most appropriate form of tenure for these lands and the most appropriate managing authority .

The Council has recommended the establishment of a comprehensive system of 27 national , state and regional parks, a large multi-purpose park containing all public lands in the Yarra Valley , reference and education areas together with wild life reserves for a number of sites containing valuable faunal habitat . Large tracts of land are recommended to be utilised for timber production .

Many of the proposed parks contain water supply catchments and , where appropriate, the Land Conservation Council considers that these should be proclaimed under the Soil Conservation and Land Utilisation Act . The Council indicates that wherever possible there should be multlple use of catchments and that where recreational uses of storages Is permitted it must be carefully controlled to ensure adequate protection of water supply, the responslblllty for this being with the Water Supply Authority. The Council also Indicates that it believes that In most situations It Is not necessary for a Water Supply Authority to control and manage all land In Its water catchment. It indicates that public authorities managing land within a proclaimed catchment should consult and co-operate with the Water Supply Authority and

"1:1,000.000 ~

the Soil Conservation Authority regarding location, timing and type of management activities in the catchment . It also indicates that the Water Supply Authorities should control and manage the buffer strip around storages and diversion works in addition to the actual water works area and makes recommendations relating to the appropriate water supply authority and the width of buffer for storage areas and diversion works within the study area .

Hardwood production is an important activity in a significant part of the Melbourne Study Area and the report, in effect , recommends that most timbered land In the area be used for hardwood production except in defined area where landscape or conservation values are considered to be of greater importance. Similarly the need for extension of soft wood production In some areas Is recognised but extension of exist ing areas is generally recommended to be met by purchase of private property .

Other sections in the report relate to the establishment of flora and fauna reserves , bushland reserves where appropriate to maintain the local character and quality of the landscape, coastal reserves , public land and water frontages abutting rivers and streams, roadside conservation and highway parks , education areas and school plantations, historic areas containing Aboriginal relics or those having historical or archaeological significance .

The final recommendations of the Land Conservation Council, Victoria, were published In January, 1977. The report contains 120 pages and Is accompanied by 16 maps showing existing and proposed use of public lands within the study area .

Editor's Note: This Is a significant recommendation with far-reaching lmpllcatlons. Comments are Invited on the subject of catchment control from members of the Association or persons Involved In water supply management.

LANO CONSERVATION COUNCIL MELBOURN E STUDY AR EA

15

THE DESTRUCTION OF WASTE CYANIDE WITH HYPOCHLORITE by G. E. Mapstone, M.Sc., Ph.D., B.Com., D.Sc., F.I.E. Aust. and B. R. Thorn, Dip. Eng. (Chem.), Grad. I.E. Aust.

Swinburne College of Technology, Hawthorn, 3122.

This paper was presented at the conference of the Institution of Engineers Aust., Canberra, 15th June, 1977.

Summary

Cyanide is very rapidly oxidized to cyanate and cyanogen chloride by hypochlorite. Since these reaction prod ucts are also rapid ly oxidized by h_ypoch lorite, sufficient oxidant must be used to comp lete both stages of the reaction before all the cyanide is destroyed . Any cyanogen chloride remaining in solution is rapid ly hydro lysed to cyanate . However, the evolut ion of nitrogen in the second stage of the reaction can lead to the discharge of dangerous amounts of the highly toxic and lachrymatory cyanogen ch loride into the work place. The control of this escape would appear to be the most important feature of the treatment process .

Introduction

The destruction of waste cyanide by oxidation with hypoch lorite or chlorine is a long establ ished industria l practice (eg. White, 1910; Southgate, 1948; Bessel ivre, 1969; Koziorowski & Kucharski, 1972) . Both cyanate (Dobson, 1947) and cyanogen chloride, (Eden, Hampson & Wheatland, 1950) are formed as products of the reaction, and both can react with further hypochiorite to give nitrogen and carbon diox ide . Recent work (Mapstone & Thorn, 1976) has shown that the overal I picture of the reaction between cyanide and hypochlorite can be written : CN' + CIO'

~ i t

CNC I

HYDROLYSIS

CIO'

N2 + CO2

CNO' CIO'

N2 + CO2

In both stages the reaction kinetics are second order, being first order with respect to the reactant and to hypoch lorite.

In Stage A the parall el chemical reactions, which take place in approximately equal amounts, are: NaCN + NaOCI + H2 0 - CNC I + 2NaOH (1) 16

and NaCN + NaOCI - (2) .

NaCNO + NaCl The parallel chemical reactions in Stage Bare: 2NaCNO + 3NaOCI' + H2O N2 + 5NaCI + 2NaHCO3 + H2O (3) 2CNCI + 3NaOCI + 4NaOH N2 + 5NaCI + 2NaHCO3 + H2O (4) In Stage A the reaction rate is unaffected by the nature of the alternative products formed and has a very low temperature coefficient . In Stage B the rate of oxidation of cyanogen chloride and of cyanate by hypochlorite would appear to be very nearly the same if not the same .

Consequent l y the hydrolysis of cyanogen ch loride to cyanate would have no effect on the reaction times and the process can be taken, at least as a close approximation, as two consecutive second order reactions with one reactant (hypochlorite) in common .

equations describing the reaction is such that no algebraic relationship has yet been derived that would give the variation of the concentration of cyan ide and its first stage oxidation products with time.

An analogue simulation programme was therefore prepared and run on the digital computer to give the required data: the results presented in Tables 1 and 2 show that the reactions are essentially comple f e within ten seconds after mixing . Also , even with a large excess of hypochlorite over that required to destroy the cyanide alone, a significant amount of the cyanide was left unoxidized as long as some of the first stage oxidation products, cyanate and cyanogen chloride, remained. Complete destruction of the cyanide therefore theoretically requires sufficient hypochlorite (2.5 mol/mol) to destroy also all the cyanate and cyanogen chloride formed. This is in agreement with industrial experience that a minimum of 2.5 mol of hypochlorite or chlorine per mol of cyanide is required if all the cyanide is to be oxidized .

The treatment of complex metal cyanides have not been included here since the necessary kinetic data has not yet been obtained.

Cyanogen Chloride

Reaction Kinetics

Both reactions are of second order although the stiochiometry of the oxidation of cyanate or cyanogen chloride requires 1.5 mols of hypoch lorite per mol of cyanide . The reaction kinetics can therefore be written dx dt = · k1 (a-x) (b-x-1 .5Y) (5) dy dt = k2 (x-y) (b-x-1.5y)

(6)

where a = initial concentration of cyanide M L"1 b = initial concentration of hypochlorite M L:' 1 = time in seconds M L·1 x = amount of cyanate oxidised ML"1 y = amount of cyanate + cyanogen chloride oxid ized M L:' 1 k 1 = reaction rate constant for Stage A = 0 .23 L M· 1 sec · 1 k 2 = react ion rate constant for Stage B = 0.13 L M ·1 sec ·1 (18°C for both of the reactions.)

The co mplexity of the differential

In large scale practice the highly tox ic cyanogen ch loride that is formed in approximately equal amounts with the cyanate in the first stage of the reaction (i.e. at iOncentrations equal to ha lf the values g iven in Tab le 2) is very not iceab ly formed and evolved from the system . Its unpleasant lacrymatory properties are noticeable at 0.5• ppm (Steere, 1967) which is below the odour thresho ld , and 159 ppm i.e. 436 mg/m3 is fatal to man in 10 minutes; (Steere, 1967) . The evolution of nitrogen from Stage B of the reaction means that this unpleasant and highly toxic material is inevitably evolved into the working area . Workmen in the area therefore must always be equipped with goggles and breathing apparatus .

Because the presence of cyanogen chloride is so noticeable its final disappearance is usually taken as indicating the end of the treatment process . Th is would appear to be due to its hydrolysis to cyanate in the alkaline solution . Using the kinet ic data of Eden & Wheat land (1950) for the rate of hydrolysis of cyanogen chloride at 18°C (k = 60 M L· 1 sec -1) and assuming that the alkaline solution is buffered, then the cyanogen chloride concentration will be reduced by a factor of ten in 2.8 minutes at pH 11, in 8.8 minutes at pH 10.5 and 28 minutes at pH 1O, and 280

minutes at pH 9. . These figures emphasise the need for raising the pH for the treatment to be effective.

The minimum retent ion of ten minutes with pH 10.5 to 11 used in industrial practice therefore corresponds with a twenty to thousand fold reduction in the concentration of dissolved cyanogen chloride which, from Tab le 2, is very low after about 10 seconds. Obviously, the preferred 20 minutes retention time will reduce the residual concentration to a negligible level, particularly when this is the usual excess of hypochlorite.

The limited data of Eden, Hampson, & Wheatland (1950) for the volatility of cyanogen chloride over water, has been extended using the Clapeyron-Clausius relationship and presented in convenient nomographic form in Figure 1.

The dashed line in the nomograph shows that nitrogen (or air) escaping from a solution containing only 25 ppm of . cyanogen chloride at 15°C will contain the highly toxic concentration of 436 mg M-3 of cyanogen chloride or 159 ppm.

One mol of nitrogen is finally evolved for each two mols of cyanide oxidized, and much of this will have been evolved in the early stages of the reaction while the cyanogen chloride concentration is relatively high . This explains the rapid evolution of cyanogen chloride into the atmosphere of the work place and the consequent need for worker protection and adequate area ventilation . The lack of instantaneous and complete removal of gases containing cyanogen chloride means that it would be detectable in the work area even after it had been reduced to a negligible concentration in the solution .

Subsequent treatment After the treatment has been allowed to go to completion, the pH will have to be lowered before it can be discharged to the sewer. In addition, if chromate is present, the pH may be lowered to 2 or less so that it may be reduced with su lphur d ioxide . At this pH any unoxidized cyanate wil l hydrolyse, first to carbamate and then to carbon dioxide. The evolution of carbon dioxide on acidification has therefore frequently been claimed as evidence of this hydrolysis of cyanate.

The data from Table 2 show that, with normal practice in which more than 2.5 mols of hypochlorite are used per mol of cyanide, the residual cyanate concentration will be negligible. The carbon dioxide evolved at this stage wi ll be from the carbonate formed in Stage B of the process.

Conclusions The application of the kinetic data on the oxidation of cyanide and cyanate with hypochlorite has allowed an analysis of the treatment of industrial cyanide wastes and explains various features of the process. The evolution

C)

CONCENTRATION

/

N 0

0

OF

CN Cl

IN

/I

w 0

/

WATER,

ppm.

/

/ /--i

w

0

m

/ /

3:

0

7J

om

/

::0

)>

--i C ::0

m 0

/

/ /

CONCENTRATION / OF CJ)

0 0

(Jl

/~

0 0

/

I

CNCl w

IN

AIR

0 0

0

mg / m3 _.

N 0 0

0 0

0

I

t.

Fig. 1. Volatility of cyanogen chloride over water.

of nitrogen gas during the first stages of the reaction carries toxic cyanogen chloride into the air space above the solution and is the main process hazard. Any cyanogen chloride remaining in solution after the oxidation has been completed (generally 10 to 20 seconds) will then hydrolyse to cyanate.

This hazard could be overcome by carrying out the treatment in a closed

vessel and purging the air space above the reactant solutions through a hypoch lo rite wash .

Further work is needed to determine the effect on the reaction kinetics of heavy metals such as silver, zinc, and copper, etc. which give oxidizable cyanide complexes . Also some technique is required to break down the nickel and iron complex cyanides which are not attacked by hypochlorite.

TABLE 1 Residual cyanide M L- 1 (Initial concentration 1.00 M L- 1 )

Seconds hypochlorite, ML- 1 1.0 1.4 1.8 2.2

0.332 0.183 0.097 0.021

2

5

10

0.285 0.140 0.057 0.004

0.280 0.129 0.043 3 X 10-4

0.280 0.129 0.042 2 X 10-5

•

600

0.280 0.129 0.042 8 X 10-13

TABLE2 Concentration of cyanate plus cyanogen chloride M L: 1 (NB. Concentrations of these will be approximately equal)

Seconds hypochlorite, ML-1 1.0 1.4 1.8 2.2 2.6

0.522 0.538 0.491 0.410 0.320

2

5

10

600

0.533 0.524 0.434 0.302 0.180

0.534 0.518 0.399 0.216 0.048

0.534 0.518 0.397 0.194 0.022

0.534 0.518 0.397 0.191 2 X 10-5

REFERENCES BESSELIVRE , E.B ., (1969) , The Treatment of Industrial Wastes, New York, McGraw-HIii. DOBSON, J.G., (1947), Sewage Works, J., 11; 1007.

EDEN , G.E., HAMPSON, B.L. and WHEATLAND, A.B., (1950), J. Soc. Chem. Ind., 69; 244-249.

EDEN, G. E. , and WHEATLAND, A.B ., (1950), J. Soc. Chem. Ind., 69; 166-169.

KOZIOROWSKI , B., and KUCHARSKI, J ., (1972), 1st English Ed. , New York, Pergamon.

MAPSTONE, G. E. and THORN, B. R., (1976) Unpublished data STEERE, N. V. (Editor), (1967), Handbook Laboratory Safety, Cleveland, Chemical Rubber Co. SOUTHGATE, B. A. , (1948). Treatment and Disposal of Industrial Waste Waters, London, H.M.S.O. WHITE , H. A., J. Chem . Sl>c. S. Air., (1910), 11;

15.

17

j

RECENT DEVELOPMENTS IN HYDRAULICS WITHIN THE HYDROELECTRIC COMMISSION OF TASMANIA PARTII P. T. A. Griffiths THE CAVITATING CONTROL ORIFICE The speed of operation of many an hydrau lic machine is contro lled by the passage of oil or water through an orifice. Somet imes it is important that there shou ld be no easy way of altering the characteristic of this orifice such as when incorrect adjustment could convert a hil ltop valve from a safety device into a t:,omb to destroy the pe nstock it is designed to protect.

Frequently an orifice is located in a pipe system in which the hydraulic losses vary greatly with temperature and discharge and these losses then inf luence the discharge through the orifice. These losses then complicate design ca lcu lations and alter machine performance .

For some time the H .E.C. has been us ing a contro l orifice which greatly simp li fies calcu lation and wh ich makes the operat ion of the machine it controls almost independent of hydraul ic losses in the contro l circuit. This has been named the cavitating orifice because, under all important conditions of operat ion, cavitation occurs immediately downstream of it. The occurrence of cav itation causes the pressure immediate ly downstream of the orifice to be vapour pressure. The orifice is located normally in the body of a servomotor so that there are very smal l hydraul ic losses upstream of it . The or ifice discharge is then dependent on ly on the pressure in the servomotor above vapour pressure, the area of the orifice and a constant discharge coeff icient. This applies for an extremely wide ra nge of Reynolds numbers, and the discharge is computed from the familiar equation:Q = CA(2gH)½ where H

=

head above vapour pressure in the servomotor a = the orifice discharge = orifice area A and C = the orifice discharge coeffic ient which has a va lue of about 0.6.

The or ifice has a length which is tw ice the diameter with sharp edges, is checked for size and absence of burrs by exam ining amplified images and sometimes tested on a rig .

Bas ic information was obta ined from t he literature on diesel injection equipment, but model tests using water and 18

oil to extend the Reynolds number range of the data available were con ducted. One main aim of the tests was to confirm the conditions under which cavitation will occur downstream of the or if ice . Provided the pressure downstream of the orifice is not more than 50% of the pressure in the servomotor and that the servomotor pressure is above about three atmospheres, the orifice will cavitate quite happily , and suffers little or no cavitation damage because the cavitation cavities co llapse clear of solid surfaces.

Fig. 7 shows the control circuit of the Wilmot hil ltop valve which uses cavitating control orifices to simpl ify the circu it and increases its secur ity.

"

02

/ l1

LJ

PUMP

WILMOT HILLTOP VALVE CO NT ROL S YSTE M FIGURE 7

S 0102

TANK SERVOMOTOR ORIFICE

~ ~!} LINES V

CHECK VAL VE

The circuit involves two servomotors label led S supp lied by oil lines L 1 and L3 from the vane pump P. When the hi ll top valve ope,Is most of the oil from P flows back to tank T via line L2 and cav itating or if ice 02. The pressure immediately upstream of 02 is independent of losses in L2 and depends on ly on the discharge through 02 .

The capacity of pump P varies only by a few percent with pressure and the capacity is chosen so that the pressure upstream of 02 wil l be suff icient to force oi l through lines L 1 and the or ifices 01 into the servomotor S to open the hi ll top valve . But it wil l fu lly open the valve on ly when pressure on both sides of the valve blade are the same . Oil then passes from the servomotors back to the tank via line L4 .

Under these conditions losses in lines L1 and the orifice 01 are small.

The pressure at 02 is suff icient to open the hilltop valve blade on ly a few degrees when pressures across the blade are unba lanced . The va lve stalls w ith the discharge of a few cusecs at normal upstream pressure .

The valve is held by a latch in the fully open pos ition . When valve closure is initiated against f low, the valve wil l close whether pump P is operating or not . Generally pump P wil l not be operating because initiation of closure cuts supp ly to the motor and a wel l chosen motor would come off on overload.

When the pump is not operating during valve closure, the discharge through orifices 01 wil l be independent of the losses in lines L1 or the head upstream of 01 or the losses in line L2 .

It will also be sensibly independent in line L4 because the pressure on top of the pistons can vary from a few p .s.i. be low atmospheric pressure to vapour pressure whi le the pressure beneath the servomotor pistons will be at or above 1000 p.s.i. Orifices 01 wi ll cavitate through the entire closing stroke .

When the pump is operating during the closing cycle, the valve will close at about ½rds its normal speed until it sta lls near the ful ly closed position .

While the pump operates the hilltop valve discharge Is a few crnsecs .

In the design of this sort of circuit, one has a few things to keep in mind.

The main one is that the press ure downstream of . an orifice , which is required to cavitate, should not exceed say 40% of t he pressure upstream of the orifice.

THE DESIGN OF A VALVE BYPASS Frequently it is necessary to fi ll the conduit downstream of a va lve through a bypass system. The head across the valve may be high and a good deal of vibrat ion due to cavitation occurs in some bypass systems which can q ui ck ly cause structural damage.

H .E.C. bypass systems are designed so as to m inimise cav itat ion and vibrat ion without using elaborate va lves . Care is taken to ensure that cav itat ion cannot occur in the bypass system and that the energy of the high pressure jet is d issipated where it can do no damage . Cavitation is prevented by creating appropr iate pressure by means of a downstream control nozzle, wh ich is also used to direct the jet .

At Lemonthyme one could be unaware that the bypass system of the hilltop valve was operating if it were not for a qu iet sound coming, not from the area where the energy was

being dissipated, but from an upstream elbow which feeds the bypass pipe.

It is usually sound policy to try to dissipate energy well clear of important machinery and in as large a body of water as possible.

The energy dissipated downstream of a hilltop butterfly valve can be great and so can be the vibration of the valve until air is admitted to cause the jets issuing past the valve blade to spring clear of that blade and to dissipate their energy well downstream of it.

THE PARANGANA SLIDE GATES The Parangana Dam diversion tunnel was to have been sealed by simple stoplogs 24 feet wide by 22.5 feet high , when belatedly it was decided to provide facilities within the stoplogs (or gate) for dewatering the storage at the rate of 2 500 cusecs under a head of 130 feet.

It was decided to make the logs in three parts, the lower two to be 9 feet high by 24 feet wide while the top part was to be 4.5 feet high. In each of the lower parts was to be a slide gate to cover a water passage 6 feet wide by 4.5 feet high . The three components would be placed in position separately and linked together for removal as a single unit by flotation equipment.

Normally slide gates of this type are supported by structures which are massive and which yield very little under load . In addition it is usual to have two gates in series in case one should fail. The large components of the diversion tunnel gate were relatively flexible in that maximum deflection under load was about ¼ inch and there was no reasonable way of mounting two gates in series. As a result it was necessary to make the whole assembly as vibration free as possible and to ensure maximum reliability of the slide gate control mechanism.

Fig. 8 shows the solution. The two slide gates are mounted on the upstream side of the skin plate of the 9 ft. high logs and the skin plate is on 9..llE GAJE

I

(

II

the upstream side. The slide gate shape was dictated by hydraulic model tests and is operated by two double acting hydraulic rams so that, if the controls to one ram were to fail, the other ram would still be capable of operating the gate. The trash racks upstream of the diversion tunnel intake were designed so that any trash passing the racks could be severed by the sharp nose of the slide gates.

The details of the skin plate and the elements downstream of it are such that water passing through the gate does not touch the gate again after leaving the skin plate . In this way it was hoped to minimise vibration however, the 9 ft. by 24 ft . gate sections were designed to be as tough as possible to withstand vibration should it occur . This dictated attention to weld details particularly on the tension components and the use of friction grip bolts where it appeared unwise to weld and the whole assembly was stressed relieved. In the end it was concluded that the precautions taken to toughen up the gate element against vibration added little if anything to its cost whilst the use of friction grip bolts simplified construction at some points .

The slide gates have been operated under full head and their operation has been observed from beside the emerging jet. Except at very small openings , when stray jets drum on the metal work downstream of the skin plate.

These gates were recovered when permanent facilities were built in the Parangana diversion tunnel and subsequently were installed at the Scotts Peak dam to provide emergency dewateri.ng facilities .

As a further example of multiple use the gate which was used to close the Wilmot diversion tunnel was also used to close Devils Gate, Cethana and Paloona diversion tunnels plus the second stage diversion conduit in the Gordon dam . This gate is in 5 sections or logs each of 10 tons weight and is 24 feet wide by 22.5 feet high . It was recovered for use in emergency in the Mersey Forth area and for the Pieman River Power Development .

9<H< FUTE

REVERSED RA!lAL GATE

SICE ARMS

Ba.TS

600J OJSECS AJ 200 FEET

,uo

OOJ'EO Ft.At«S

Tt>.PEREO GAl'E BOO<

PARAII.GANA SLOE GATES FIGURE 8

GORDON REVERSED RADIAL GATE FIGURE 9

STFFENN3 FR.A.'"£

••

The logs are assembled into a single unit in the gate slots ',1{011 clear at the invert, and then lowere'tl by hydraulic rams . A recovery cable is attached and the rams and other equipment used for installation are removed before the water rises or are floated out whilst a barge is used to recover the gate from water up to 350 feet in depth .

THE REVERSE RADIAL GATE Gordon dam has an 8 ft. dia. control filling outlet which can operate under a head of 200 feet to pass about 6 000 cusecs. It was intended to have more than one such outlet at different levels but to have only one downstream control gate which would be moved from one outlet to another as required.

The cheapest control gate for this purpose was a reversed radial gate as shown on Fig .9. When It was decided to have only one outlet , it was decided also to retain this concept, the design and model test of which were well advanced.

THE SCOURING ROCK TRAP Lemonthyme power tunnel is unlined and to achieve a reasonably smooth invert the tunnel spoil was removed to near the rock points and rolled . When water passes over an Invert like this some of the invert material Is carried downstream where it must be trapped to prevent damage to the penstock paint system and to the turbine .

The rock for the most part is schist which provides a relatively large proportion of flaky particles when it is fractured by blasting or broken by earthmoving equipment. It would have been possible to have• made a very large conventional rock trap or perhaps a smaller one which could have been emptied as required when the tunnel was dewatered , Iii ow ever, Fig. 10 shows what was done to capture material which moves along the invert .

Hor izontal baffles at close spacing were arranged to trap material moving downstream near the invert by means of the eddy action caused by the baffles.

After passing through the baffles the material settles to the bottom of a hopper in the base of which is a large hole . Below the hole in the base of the hopper is a chamber into which material from the hopper passes . The material in this chamber lies at its angle of repose and , when sufficient material has passed into the chamber, the material seals the hole in the base of the hopper . If additional material falls into the hopper, the hopper fills but there is not further movement of the material in the chamber below the hopper .

The dimensions of the chamber below the hopper are such that , when the hole in the base of the hopper is sealed, there are empty passages on both sides and downstream of the material in the chamber. Upstream of this material is a wall shaped to cover only the 19

SCOURING ROCK TRAP ROOF CRANE

2000011TO INTAKE

FLOW -+

~ : I

SUPPLY PIP!:: - - - - / UPSTREAM WUL

~

-· SCOUR CHAMBER

,,.

TOWER

PASSAGE

SCOUR CHAMBER

\

FOR WATER

TRAPPED MATERIAL

SECTION B · B

/

GATE HOIST

EDDIES

l ~BAFFLES FLOW -+

\~-------:~::

-.::!.-_-_-:.,-=_:-_:-_--:..~=----~

PLAN

material lying at its angle of repose.

Upstream of this wall is a pipe which can supply water to the chamber via passages between the ends of this wa ll and the sides of the chamber.

Downstream of the materia l lying at its ang le of repose is a carefu lly shaped transition which terminates at the scour pi·pe which extends to the tunnel portal where there is a butterfly guard valve and a reversed radial gate.

When the hopper is to be emptied, the butterf ly guard valve is opened and care is taken to ensure the blade is wide open and safely sheltered beh ind a member to protect the blade from the stones soon to rush past it.

The reverse radial gate is then opened and water f lows from the tunne l, past the wal I upstream of the material in the scour chamber, past the material lying at its angle of repose and so into the pipe downstream of the chamber.

As the water passes on both sides of the mater ial in the chamber that mater ial is eroded and swept down the pipe . As material is eroded from the chamber, further mater ial falls from the hopper and the process continues until the hopper and chamber are empty .

The baff le system which is very sim ilar to that used in the Poatina trap was model tested as was the hopper, the scouring chamber and scour pipe.

The novel feature of the trap is the control device it contains which has no mov ing parts and which, by its dimensions, dictates which of the many possible modes of operation the system wi ll adopt. As the flow past the trapped material increases, the rate of erosion of that material increases and the head loss in the downstream conduit wi ll also increase. This causes the f low to decrease and the rate at which material is ·eroded also to decrease . This decreases the head loss so the f low increases again . cho ice of scour chamber By dimensions, it is possible to cause a un iform f low of eroded material with the particles moving at constant velocity.

It is also poss ib le to make the rate of erosion of the material sens ibly uniform while individua l partic les skip and hop down the pipe. Again it is possib le to make the system hunt in a variety of ways inc luding that in which the flow

20

~ E S H SCREEN

FIGUR E 10

will stop almost completely with large heaps of materia l at rest at intervals along the pipe . After a while the flow will increase; most of the material in the pipe will be removed ; the flow will reach a peak and erode at a high rate .

Later the flow wil l almost cease and then the whole process will be repeated.

Tests showed that it is possible to b lock the system only with particles with dimensions of about half the pipe diameter or with the help of sticks .

Sticks are excluded from the system by a screen beneath the baffles and the mode of operation selected was that in which particles move continuously down the pipe .

The scouring system works wel l and 50 cu.yds. can be removed within about 5 minutes. Material ranges from about 1 / 16 inch up to the occasional 3 inch stone and larger pieces of flaky material.

The system of transverse baffles to divert material into the hopper has worked reasonab ly well. With velocit ies of 5 ft. per second a small percentage of particles move along the tunnel f loor and skip over the trap. These are generally up to about¼ inch partic les .

Since the materia l removed from the rock trap can be measured the rate at which material is caught can be known at all times and some hundreds of cubic yards have been removed from the tunne l by the scouring rock trap.

THE GORDON POWER INTAKE The Gordon power intake shown in Figure 11 will be tested by mid -1977.

It consists of a 200 foot high tower standing as an extension to a vert ical shaft about 450 feet deep with an internal lined diameter of 27 feet and it is designed to pass up to 15 000 cusecs under normal operating cond itions to the five machines of the underground Gordon power station.

At the base of the tower are six large openings protected by arched trash racks and sealed by six bulkhead gates which can be placed under st ill water conditions only . For sealing against f low, a cy linder gate is provided which is capable of closing very quickly aga inst discharges of 15 000 cusecs and more. A roof crane has been

GORDON INTAKE FIGURE II

provided for the placement and remova l of trash racks , bulkhead gates and for other maintenance and construction purposes.

When the decision was taken to use a cylinder gate it was known that gates of this type had vibrated seriously.

The bottom circumferential seal of the gate is 85 feet long. It has proved difficu lt to bring the bottom seal of such gates steadi ly and evenly on to an embedded sill since as the gate approaches the sil l plate, pressures under the seal fluctuate' and the whole gate tends to vibrate .

This situation is sometimes made worse by the fact that there is no lateral load to prevent tl'le gate ratt ling around in the tower. It is of course poss ible to reduce the extent of the latera l movement by small clearances between the gate guide shoes and the embedded guide members, however the use of fine tolerances can increase costs and fabricat ion prob lems .

Sometimes cylinder gates are held by suspens ion systems which are hundreds of feet long and these, when subject to fluctuating vertica l forces, have behaved like springs to perm it the gates to move up and down like forging hammers . This situation has sometimes been aggravated by long closing t imes made necessary by three rod suspensions . It has not been possib le to synchronise the operation of these rods for fast gate closure .

It is be lieved that these problems have been overcome by the use of a bottom seal embedded in frames set ih the concrete, by the app lication of a high lateral load to prevent the gate rattling and by the use of a sing le hydraulic suspension close ly coup led to the gate which can close the gate in a few seconds .

-=- -=:c=-

9ULKHEAD GATE S~OT CYLINDER GATE

CRAFT TUBE a.JTlETS.

INFLAT,BlE

:~~7 ) ~

':>E.GL - - ~..,

POINT OF

MINIMUM WIDTH ~NNULAJL_ PJ.SSAGE

.J

GORDON GATE S~AL

The arrangement of the bottom seal is shown in Fig . 12. The gate travels to its fully closed position and then a lateral seal is inflated to close a small annular water passage . The shape of this annular water passage is such that, if · the seal fails to inflate, water will move through the passage without vibration or cavitation . The precise details were determined by model tests and full scale seal elements tested at prototype pressures .

To prevent the gate rattling within the tower, a lateral load will be applied to the gate. Selected guide shoes will be pre-loaded against the guide rails, so that the whole gate would become a spring to keep them there whilst some shoes must remain unloaded with sensible clearances to their guide rails . If this were not done, the gate could become wedged in position.

Frictional forces at the guide shoes would tend to damp vibration in any direction.

A great deal of hydraulic modelling has been done to assist in understanding how the water behaves within the gate passages and to shape the passages for good hydraulic perform ance particularly since at full f low the water velocities will be about 30 feet per second. The recess shown on Figure 12 has been provided to ensure that debris will not be able to wedge the gate which has a cutting edge to shear through any timber which could pass through the trash racks . The presence of this recess influences the shape of the surface downstream of it.

This bottom seal provides a very efficient hydraulic entrance to the tower.

It was considered reasonable for this gate to close quickly in an emergency and full gate travel will be about 20 seconds. During closure against flow , the power dissipated in the hydraulic ram control system wou Id be 500H P for the 20 second closure and the ram load about 80 tons.

To undertake the design of a gate of this type requires the use of a reliable hydraulic laboratory organisation plus a sk ilful and experienced team to undertake the structural design of the gate and tower . In add ition there were

many problems of materials selection and the control of corrosion , particularly for built-in parts .

fl--[J-0-~"" .. ~

•

THE GORDON SURGE TANK Figure 13 indicates the original proposal for the conduit system of the Gordon Power Station . It involves the tower intake, a short penstock system leading to the turbines and a re latively long tailrace tunnel. In the absence of expensive turbine relief valves, a tail race surge tank is essential to prevent rupture of the draft tube water columns following rejection of load . If relief valves were used, a surge tank would be desirable to improve the ability of the station to control system frequency .

DIAGRAM Of

Ra.EASE

rum

.

.

--

TRAPPED AIR

GOROON

SUlGE

··

TANK

FIGURE U

any air, which goes into the tunnel as the water goes out of it, is trapped so that it will cush'ion the blow when the water comes back.

A separate shaft would be provided which would drain quickly and admit air to the tunnel within a second or so ~fter the start of full load rejection .

INTAKE TOW ER ----;7 t AKE GORDON

INLET

_( TAILR ACE TUN NEL

GO RDON CONDUIT SYSTEM FIGURE 13

A conventional surge tank system would be as shown . It involves depressing the upstream part of the tailrace tunnel and a large tank extending to above the roof of the station.

It was intended if possible to avoid having to depress the upstream part of the tunnel because it was considered it would complicate construction and subsequent draining of the tailrace tunnel.

Model tests showed that severe water hamm er occurred for a conventional ta nk with a tailrace tunnel which was not depressed . This was because the tailrace large ly emptied following load rejection and later the water came rushing back and struck the roof of the tunnel in the vicinity of the surge tank. To avoid this, the arrangement was changed to that of Fig. 14 so that

Most of the air would be trapped by water covering the air entrance soon after the water starts to come back along the tunnel . The trapped air brings the water to rest at a pressure level close to the downstream pond level and the system is sensib ly aperiod ic.

It was anticipated that, after very severe load rejection, some minutes would pass before the machines would be resynchronised. During this period the trapped air would be released via the ducts shown . Initially the air discharge would be high but decreases progressively as the water rises and covers the duct intakes. The air could be released at an average rate of about 4 000 cusecs and could take about four minutes . The maximum air pressure was expected to be about 10 p .s.i. The top air release duct would

21

be sucn that no severe water nammer could occur when the last of the air Is released .

If a partial load rejection occurred, or the machines were started up before al l the air were released, some air would be driven to the tunnel outfall and released.

The presence of the separate air shaft enables the surge tank to have a severe thrott le which enables the tank to be much smaller than otherwise.

In fact, the throttle proposed would have a head loss characteristic about two orders higher than that normally encountered and the tank would be perhaps 20% of normal size. All has to be dimensioned with care to ensure

the water in the air shaft does not become unstable.

Extensive tests were involved in the preliminary design of this tank including both mathematical and hydraulic models with the hydraulic model studies indicating in particular, the behaviour of air in the system. The matnematical models relate to the possibility of rupture of the draft tube water columns, surge tank stability and the effect of the tank on frequency control.

The range of possible tailwater levels that could occur downstream were reduced in 1976 and a mainly unlined tai Irace tunnel adopted. For these reasons it was decided not to proceed with the tank as initially designed but

to replace it with a conventional surge tank .

ACKNOWLEDGEMENTS: Appreciation is expressed to the Knight, Commissioner, Sir Allan C.M .G., M .E., B.Sc ., B.Com., F.I.E .

Aust ., for permission to publish this paper and to thank those who have assisted with its preparation particularly, Mr R. F. Edmondson Section Engineer, Gates and Valves, and his staff together with the many people throughout the Commission who have worked on these projects and whose combined efforts have resu lted in some interesting developments in the general field of hydraulics.

OPERATOR TRAINING IN VICTORIA

by Robin Povey

The State Rivers and Water Supply Commission of Victoria is proceeding rapidly with extensive proposals for establishing a permanent centre for training Operators of water and wastewater treatment plants.

The proposals, prepared by the Water Commission's former Chief Engineer for Town Water Supplies - Mr. J. D. Lang , involve the erection of a building for training up to 36 Operators at any one time. A permanent staff of up to 5 will ultimately be appointed to full time duties at the Centre. The complex is being located on a site leased from the Department of Agriculture at the State Research Farm, Werribee - some 30 km south-west of Melbourne. At this site, the Department of Agriculture already has an existing hostel which will be made available for Operators needing to "live-in". Extensive renovations of the hostel are being carried out by the Water Commission together with the other work necessary for establishing the centre.

Operators from Government, Local Government and Industrial plants throughout Victoria are expected to take advantage of the Training Centre. It is also hoped that Operators from both Commonwealth and other State Governments will join with Victoria to make the Centre the leading training unit of its type in Australia.

While there are no treatment works on the actual site , there are plants

[/

. .,.. <

(either in operation or proposed) within travelling distance in the surrounding region, and these will be used for practical training . The new building for the training complex will have an area of some 500 square metres comprising two classrooms, laboratory-research area, library, recreation room and offices and storerooms. The contract for its construction was awarded to Cemac Victoria Pty. Ltd . Work on this building and the renovations are now well advanced and it is expected that the first course could commence later this year.

Details of courses to be held have not yet been finalized but a suitable balance between theory and practical work will be kept. Initially it is proposed that courses prepared by the Water Pollution Control Federation (of America), suitably modified, will be utilized. This will allow the newly appointed staff to conduct courses as soon as possible and concurrently prepare courses specifically orientated to local conditions and needs. While the centre will accommodate up to 36 students, experience with similar courses indicates that the number of operators attending the regular individual courses should be limited to about 12.

The total estimated capital cost for the scheme is $350,000 which includes $90,000 for laboratory equipment, furniture, and general training aides.

The Commonwealth Government, in support of the concept of Operator

I

Operator's Training Centre, Werrlbee, Vic.

22

/

I

'\;I,¡.

Training, provided a grant of $260,000 in the 1976/77 financial year towards the cost of the project from the National Sewerage Programme Support Activities. The Victorian Government will provide the balance of capital funds needed to complete the Centre, together with funds for the annual operating costs .

A Committee of Management for Operator Training (C.O.M.O .T.), convened by the Victorian Water Resources Council will advise on all aspects relating to the Centre. Representatives for this Committee are being sought from various organizations with extensive interests in the performance of treatment works . These include:Water Commission (Nominee to be Chairman) Melbourne and Metropolitan Board of works ' Health Department Environment Protection Authority Provincial Sewerage Authorities Association .:>f Victoria Operators Association of Victoria.

A project manager will be appointed to the Water Commission's staff to control the Centre and act as Technical Secretary to the C.O .M.O.T. The day-to-day management of the Centre will thus be the responsibility of the Water Commission.

Acknowledgment The above artic le summarizes a paper prepared by the Author for the State Rivers and Water Supply Commission's official journal "Aqua".

Robin Povey, Dip. C.E., E.W.S., is an Executive Engineer in the Local Authorities Division of the Water Commission. He has been extensively involved in the conduct of courses by the Commission for Operators of wastewater treatment works and also managed a course, on behalf of the Victorian Branch of the A.W.W.A., for operators of water treatment plants. He is currently responsible for the establishment of the Commission's new Operator Training Centre.

ENVIRONMENTAL STUDIES COURSE IN 1978 A new postgraduate Course on Environmental Studies was launched at the University of Adelaide in February 1976. The aim of the Course is to present an integrated approach to environmental management problems and decis ion-making processes so that graduates, regardless of their previous training and experience, can gain a wider knowledge and comprehensive understanding of the environment which wi ll enable them to apply their basic sk ills to the solution of problems .

The concept of the Course is not to produce specialists in Environmental Stud ies, but rather to broaden the education of technologists, scientists, economists, lawyers and others whose work may in some way influence the human environment .

By bringing together graduates with a variety of skills and expertise, it is intended to train practical experts who will understand the factors involved in seeking effective solutions to difficult prob lems .

On ly twenty graduates are being adm itted to the Course in any one year.

An advertisement appeared in the nat iona l press about mid-May this year for the 1978 Course . Further details may be obtained from the Director of the Centre for Environmental Studies , Dr. J . R. Hai ls.

"WASTE EXCHANGE" Society is generating ever increasing quant ities of waste and consuming increas ing quantities of raw material s; max imum use needs to be made of these materials both from an economic and nat iona l point of view . The Metropo litan Waste Disposal Authority in Sydney, New South Wales, is committed to a policy of promoting recyc li ng of waste in order to conserve raw materia ls and reduce the demand for that valuab le resource - space for disposal of waste .

In li ne with this po licy the Authority has decided to establish an Industrial Waste Exchange which will put waste generators in touch with potential users of waste . There is much incentive for companies to try and exchange their waste, as a successful transaction will resu lt in the waste generator not having to pay waste disposal costs and the waste recipient will save raw material costs. Some examp les of wastes that could be exchanged are :(1) Waste oils and so lvents - these cou ld possibly by used as a fuel.

Alternat ive ly, solvents can be disti ll ed and the distilled solvent reused .

(2) Waste alkalis can be used for neutralisation of acidic effluents vice versa.

(3) Organic waste~ - some of these can be used as top dressing on golf courses and parks.

(4) Phosphoric acid - this can be used in the manufacture of fert ii izer, etc.

The first Waste Exchange was established in 1973 in Hamburg (West Germany) . Since then Exchanges have been set up in Holland , Belgium , Switzerland, Austria, Italy, U.K. , U.S.A. and New Zealand . The Hamburg Exchange initiated exchanges equivalent to 3% of the total waste stream .

The Authority 's Waste Exchange will be concerned with waste materials originating from manufacturing processes . It wi ll exclude wastes from domestic sources and those scrap metals for which adequate commercial markets are already in existence .

A register will be maintained of waste materials offered and waste materials sought and this information will be pub lished in the form of listings every four months . In order to protect the identity of participating companies, each item listed will be assigned a code number. Responses to listings will be promptly forwarded to the firm wh ich made the listing; - that firm can then choose the responder with whom it wishes to negotiate. There will be a fee of $5 per item listed and the fee is intended to cover only mailing and stationery costs .

The Authority expects that, besides wastes that it can help exchange, it will also be ab le to assist industry with adv ice on how to reduce waste disposal costs , e.g. many commercial and manufacturing establishments are not aware that by separating their waste paper they then have a waste material which they can sell rather than pay to have removed . The Waste Exchange will only prove successfu l if industry is prepared to " give it a go" . The be contacted by Exchange can telephoning the Metropolitan Waste Disposa l Authority on 412-1388.

ALLAN PETTIGREW CONSULTANTS PTY . LTD .

Consultants in Pol lution Control & Water Treatment P.O. Box 94 - ROCKLEA 4106 TELEPHONE : Business 275-3322 Private 200-1176

Manufacturers of a wide range of munic i pal and industr ia l water treatment plants for both large and small communities and industries.

Also the " Dracco" range of Air Po ll ut ion Contro l Systems.

GATX-FULLER AUSTRALASIA PTY. LTD. ÂŽ

454-456 Pacific Highway, St. Leonards , N.S.W . 2065 Telex 21693 Telephone Sydney 439 8177

ERRATA: We apologise for the following errors in typo,graphy in the paper on "THE USE OF NATURAL TRITIUM FOR EVALUATING AQUIFER RECHARGE".

by G. B. Allison which appeared in Vol. 4 No. 1, March 1977 issue.

1. Introduction, 4th paragraph, the first bracketed expression should read (as 1 H 3 H 0) 1 1 2. Equation (1) should read C = C 0 exp (- l t) where C0 (TU) is the initial concen tration, t (yr) the time since the water fell as rain and ,t (yr - 1 ) the radioactive decay constant .

3. Equation (2) should rdad C

=C

0

/(1

+ ..t

t)

4. Equation (3) should read t =

<"qH

In~-

5. Equat ion (4) should read ex:,

T =

r

Cn exp (- n l ) n=O where Cn is the tritium concentration (TU) of water moving into the soil profile in year n, and n is the number of years before the present.

KEITH ENGINEERING (SALES) PTY. LTD. For design manufacture & installation of Industrial Waste Water Treatment Systems.

Australia - P.O. ,Box 11, Mascot 2020.

Phone (02) 666-9042.

New Zealand - P.O. Box 124, Manurewa South Auckldnd - Phone 69005 Manurewa

Pettigrew Engineering Co. Pty. Ltd. Pollution Contro l & Water Treatment Engineers For Full Turnkey Projects 34 Reginald Street, Rockies. 4106 Telephone: 275-3322

44 Koornang Roaa , Scoresby 3179

Telephone 763 8988 W 4TII.

\

,

BOBY ;

~

BOBY ANALYTICAL LABORATORY SERVICES

m 23

CONFERENCE CALENDAR A.W.W.A. SUMMER SCHOOL HOBART, 6-10 FEBRUARY, 1978 The 1978 Residential Summer School will be held at the University of Tasmania, with live-in accommodation at Christ Co llege, a University Hall of Residence.

The School will consist of lectures, discussions and workshops, and it is envisaged that the general theme will be: Water Quality 1. Objectives 2. Management and Achievement 3. New Horizons

The Organizing Committee would be pleased to receive relevant topics, comments and suggestions on the general theme of the School from Interested individu als and Organizations. These should be received not later than 31st August, 1977.

Enqu iri es concerning the Summer School may be addressed to:Either: A.W.W.A. Summer School, P.O. Box 355 D, HOBART, Tasmania, 7001.

Or: Mr. B. 0. Healey, Environmental Department, 161 Davey Street, HOBART, Tasmania, 7000.

INTERNATIONAL WATER SUPPLY ASSOCIATION

KYOTO CONGRESS 2nd - 6th OCTOBER, 1978 A programme covering all aspects of water supply Is being arranged.

Further enquiries at this stage may be directed to any of our Federal Councillors, who have received a draft programme.

NATIONAL WATER WELL ASSOCIATION

DRILL '77 The rapidly developing twin cities of AlburyWodonga will be the location for the N.W.W.A .'s National Convent ion on October 15th, followed by schools on Advanced Cable Tool (percussion) Drilling and Pump Selection, Installation and Testing, October 16-20th.

As an integral (but optional) part of Drill '77, a study tour is being arranged to New Zealand, leaving on October 22nd for 10 days. This will cover several unusual drilling operations as well as ample opportunity to see many of New Zealand's famous sights.

For further information, contact the Executive Secretary, N.W.W.A ., Box 91, St. Ives, N.S.W., 2075 .

24

The University of New South Wales School of Clvll Engineering

SYMPOSIUM ON THE TREATMENT & DISPOSAL OF WASTEWATER LIQUIDS & SLUDGES It is proposed to hold a one-day symposium on the treatment and disposal of wastewater liquids and sludges at the University of New South Wales on January 20th , 1978.

The symposium will deal with aspects of domestic wastewater sludges and industrial liquids and sludges.

Lecturers will discuss techniques for dewatering sludges and liquids, ultimate disposal, discharge to the sewer and the characterisation of sludges.

The anticipated cost would be $28 per head including preprinted papers and lunch . Further details and application forms can be obtained from Dr. D. Barnes, School of Civil Engineering, The University of New South Wales, P.O. Box 1, Kensington, N.S.W. 2033.

A.W.W.A. Seventh Biennial Convention Canberra September 21-24, 1977 Noah's Lakeside International Hotel

REGISTRATION "PUBLIC ASPIRATIONS AND REALITIES IN WATER RESOURCES MANAGEMENT'/

The convention will be officially opened by Hi s Excellency , the Governor-General on Wednesday, 21st September. Overseas guest spe~kers will be Pro f .

Steve Hanke of Johns Hopkins University and Mr. Eric Gilliland of Thames Water . Authority who will deliver the keynote addresses.

Parallel technical sessions will be held and papers will be presented in the fields of - Water Quality Management - Advances in Treatment Methodology and Standards - Laboratory Techniques - Water Management - Laboratory Investigations.

Technical inspections will be made of the Lower Molonglo Water Quality Control Centre and the Googong Water Supply Project.

The Social Programme commences with a Cocktail Party on Tuesday evening for early arrivals and Is highlighted by the Banquet on Thursday night.

Leading industrial firms and suppliers will mount a Trade Exhibition which will be open throughout the convention .

To ensure receiving the preprinted book of papers be sure to register by 27th July . For a Registration brochure contact your branch secretary or write to : The Chairman, Convention Committee , A.W.W.A. 7th Federal Convention, P.O. Box 359, CANBERRA CITY, 2601.

PRODUCTS, PROCESSES, PEOPLE With Kent he wi ll still be able to make INTRODUCING use of his degrees in Chem . Eng. and Environmental Po llution Control as the YOUR NEW company is a leading supplier of instrumentation to both the water and EDITOR petchem industries. The complete Born and educated In New Zealand, Barrie J. Murphy joined the New Zealand Ministry of Works as a draughting cadet In 1955, graduated as a civil engineer In 1959 and was then appointed as an assistant engineer to the District Office In Dunedin and later in Wellington.

During this time he gained design and construction experience In such fie lds as airport construction, Irrigation works , roads, bridges and multistory buildings. He gained corporate membership of the NZIE In 1963.

In 1963 he was appointed senior engineer with Christchurch consultants being responsible for the design and supervision of construction of bridges, water supplies and sewerage schemes for a number of local authorities.

He joined the MMBW as a supervising engineer In 1969 being associated with the design of major sewerage projects, and In particular, the basic planning for the sewerage of the Dandenong Valley . Prior to his present appointment as Deputy Officer-in-Charge, South Eastern Purif ication Plant , he held the positions of Pol lution Investigation Engineer and Engineer for Purification Plants and Trade Wastes.

control system for the massive South Eastern Purification Plant in Melbourne, for examp le, was prov ided by Kent.

Kent, a member of the Swiss Brown Boveri Group, has just whirled Mike around the U.K. and Europe on a five week familiarisation tour to group companies. On the way home ne managed to organise the presentation of a paper on effluent treatment In sunny Surfers' Paradise at the A.I.F.S .T. Conference.

To finish on a right royal note, he reports that England was all decked out for Jubi lee year and even the skies were silver - or was that just grey! - and the si lver rain came sparkling down almost every day.

This year Kent have been awarded the instrumentation contracts for the Melton (Vic) and Oxley Creek (Old) sewage treatment plants, the Wanneroo (W.A.) and Ansty Hill (S.A.) Water Treatment Plant and four tertiary treatment plants for the Sydney Water Board .

NEW GENERAL MANAGER FOR MATHER & PLATT

NEW VICTORIAN SALES MANAGER FOR KELLY & LEWIS Mr Keith Jackson has been appointed Victorian sa les manager for Kelly & Lewis Pumps.

NEW VICTORIAN MANAGER FOR KENT Michael Dureau, well known agitator from the New South Wales Branch, has migrated south to join Kent Instruments (Australia) Pty. Ltd ., as Manager of the Victorian Division .

The new position meant giving up the Vice Presidency of the New South Wales Branch and a position on the Federal Council, but already he has squeezed himself onto the Victorian Comm ittee and back on the editorial staff of "Water" .

\

contro l and manufacturing responsibi lity for three plants and foundries wh ich produce pumps, electric motors and anti pol lut ion equipment.

During this period Mr Connor was involved with the development of a large and new type of ozone generator wh ich Mather & Platt produced In associat ion with the British Electricity Counc il and he comments that Mather & Platt will be looking for ways of introducing this and other anti-po ll ut ion equipment into Australian markets.

Mr Connor has had a distinguished career in the pumping industry, and has been chairman and member of a number of engineering and pump associations. He joined Kel ly & Lewis in 1950 as a junior draftsman and later qualified as mechanical engineer.

In 1962 he became chief hydrau lic des ign engineer, then chief engineer working in a group design team led by Mr Andy Gasiumas, an hydrau lic design engineer of international acclaim .

In 1968 he was appointed Director of Engineering .

Mr Connor comments that the company intends to strengthen Its pos it ion in the Australian pumping market as a result of recent developments by Mather & Platt In water and sewerage pump engineering as wel l as power generation equipment.

Mr Arthur W. Connor has been appointed general manager, director of Mather & Platt Pty. Ltd . He will be responsib le for group operations throughout Australia inc luding Kelly & Lewis Pumps, KL-Worth ington Pumps, Gil es & Gask in Pumps and Kell y & Lewis Mach inery .

He has recently returned from the United Kingdom where he spent nearly four years with Mather & Platt, first as techn ical director of the power division then as engineering and manufacturing director of the mach inery group.

Responsib ilit ies comprised research and development , engineering, quality

He joined the company in 1946 as production control ler then worked in the drawing office, purchasing department and sales office .

He will direct all general pump sales in Victoria, South Australia and Tasmania and be respons ible for al l distributor contacts .

25

KENT FLOW CALIBRATION LABORATORY NOW NATA REGISTERED The National Association of Testing Authorities , Australia (NATA) have registered the Flow Calibration Laboratory at the Kent, Caringbah, N.S. W., plant .

This unique facility which Is available to all flowmeter users throughout Australia, has been approved by NATA for the calibration of:Electromagnetic flowmeters Mechanical type meters (including pos itive displacement meters) Turbine flowmeters Vortex flowmeters Differential-pressure type flowmeters The Kent Flowmeter Calibration Laboratory comprises two Integrated flowmeter test rigs - one for small f lowmeters up to 125 mm (5 in) size and the other for larger flowmeters up to 750 mm (30 in) size and 380 I/s - it has a

common control room which houses the control panel for the operation of both test rigs and the monitoring of the flowmeters under test. A schematic diagram of the complete Flowmeter Calibration Laboratory is shown below.

The basic method of calibration employed with both the large- and small-flowmeter test rigs is to compare the actual amount of water which is passed through the meter being calibrated with the amount that is registered by the meter. For the large flowmeter test rig the actual amount passed is determined by volume, whilst with the small rig it is determined by weight . In either case the output of the f lowmeter under test can be expressed either in volumetric or weight units.

For further information please contact:Mr. D. J. Rickard, Marketing Manager, Kent Instruments (Australia) Pty. Ltd., 70-78 Box Road (P .O. Box 333), Caringbah, N.S.W. 2229.

Telephone: (02) 525-2811.

Or contact the Kent office in your State.

NEW LITERATUREMULTIMETERS FROM KENT

Schematic diagram of Kent Flowmeter Callbratlon Laboratory.

A new il lustrated publication is now available which gives details of the Goerz & Metrawatt range of Multimeters which are marketed throughout Australia by Kent Instruments (Australia) Pty. Ltd.

Included in the publication are both analogue and digital Multimeters, including the recently released Unigor D210 Auto-ranging Digital Multimeter.

The Multiscript range of portable recording multimeters is also included .

WARMAN VALVES

Pictured Is a 1000 mm dla. Warman double flanged butterfly valve with actuator for manual operation, recently manufactured for the Berri Irrigation Area.

In the background are a 450 mm dla.

Warman Tyta wafer type butterfly valve with manual gearbox and a 200 mm dla.

Warman Rovalco knife gate valve fitted with hydraulic operating cylinder.

Mr. D. Shakesheff (left) Is Sales Engineer for Warman International Ltd., Valve Division, and Mr. R. Barrett (right) was responsible for designing the 100 mm dia. valve.

TOTAL CAPABILITY IN

CONTROL

In Mechanical, Process and Biological Engineering Mechanical Engineering Grit removal plant Screen ing press and bagger unit Circu lar and rectangular sedimentat ion tank scrapers Sludge conso li dation tank th ickeners, mix ing tank stirrers Sludge drying bed mechanical lifters Sand bed lifters

Process Engineering Thermal and chemical sludge conditioning plants TC Incinerator for screenings Multiple hearth , flu idised bed, rotary drum sludge incinerators Static grate incinerator Disso lved air flotation Carbon regeneration and absorption systems

Biological Engineering Standardised activated sludge plant for sma ll popu lations of up to 20,000 persons Extended aeration plant.

Ae robic sludge digestion.

Diffused air activated sludge plant Automatic contro l systems for activated sludge plant

.._, HAWKER SIDDELEY WATER ENGINEERING A division of Hawker Siddeley Brush Pty. Ltd .

Vic. 262-284 Heidelberg Rd ., Fairfield , 3078. Tel. 489 2511 . ~S.W. 12 Frederick St. , St. Leonards, 2065 . Tel. 439 8444 . OLD. 193 Mary St ., Brisbane, 4000. Tel. 22 1 2155. W.A, 2 Ferguson Street, Kewdale , 6105. Tel. 68 7022 . N.Z. Goldfield , Takapuna . Auck land 9. Tel. 44 5294 .

Hawker Siddeley Group supplies electrical and mechanical equ ipmen t with world-wide sales and service.

Agents for Hawker Siddeley Water Engineering ltd . (Templewood Hawksley Activated Sludge.)

26

10SJHS

THE PARBURY HENTY RANGE OF WATER PURIFICATION EQUIPMENT INCLUDES:

SIMONACCO DISC FILTERS The Simonacco Rotary Vacuum Disc Filter provides continuous filtration of chemical slurries, mineral concentrates , sewage sludges, etc., and can be adapted to a wide range of industrial applications. Available with discs 1.8 m diameter up to 6 discs (24 sq. m) and with discs 3.96 m diameter up to 14 discs (266 sq. m) .

MANOR FILTEA PRESSES Manor Engineering Co. Ltd. equipment is supplied by Parbury Henty for sedimentation, thickening, filtration, chemical handling, pumping, elutriation, flotation, sewage and industrial effluent purification. Manor fully automated presses of the type illustrated have extensive uses for materials on short filtration cycles and having good cake release characteristics. â&#x20AC;˘

SIEBTECHNIK CENTRIFUGES The Siebtechnik Decanter is a screenless centrifuge, in which the solids are conveyed from the large to the small diameter against the centrifugal force. The worm acts as a conveyor as well as a regulating element, and its field of application includes materials which are too fine for the screening centrifuge, provided the solids have an adequate sedimentation rate, such as flotation concentrates and waste water.

PARBURY HENTV &CO.PTY. LTD.

MINING DIVISION

1 Lincoln Street, Lane Cove, N.S.W. 2066 Telephone 428 3533

Handles Water Beautifully -Applications

Typical Specifications:

"Len" Anthracite can be used:

Specific Gravity: 1.40-1.45 Acid Solubility : ' 1.0% (max) Effective Size: Type 2 0.85-0.95mm Typt 3 0.50-0.60mm Uniformity Coefficient: 1.4 Voidage: 55%

0 To increase the capacity and efficiency of existing filtration equipment

0 To reduce the capital cost of new equipment

0 For filtration of Alkaline Water: Caustic Acid Solution, Boiler Water and Oxidised Chemicals.

Distributed in Australasia by Kembla Coal & Coke Pty. Limited Box 1770, P.O. Wollongong, N.S.W. 2500.

Telephone (042) 28 7455 Telex: 29172

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The A~~ffiE[Li Aquasieve

•

• Reduces sewered waste and water pollution • Recovers reusable solids to increase total product utilisation • Requires minimal maintenance • Rapidly pays for itself • Installs easily in confined spaces • Reduces capital outlay and operating costs We are more than will ing to demonstrate this unit to you. Ring, write or call personally - let's talk.

ANZIEL PTY. LTD. 6 Bowen Crescent MELBOURNE. 3004. Australia.

Telephone 267-1333 Telex 31-308

32 Hastie Avenue MANGERE, AUCKLAND, NEW ZEALAND. Telephone 633-969 Telex NZ-2473

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51-tARl=JLES CENTRIFUGES

Sharples centrifuges for wastewater treatment

Sharples Super- D-Canter ® solid-bowl . continuousdischarge centrifuge.

Sharples SludgePak® solid-bowl centrifuge with skimmer and knife .

Sharples Nozljector ® disc-type. continuous centrifuge with internal recyc le concentrator.

No single type of wastewater centrifuge can handle all sludges - that's why Sharples makes all types.

SHARPLES-STOKES PTY. LTD. MAIL: BOX 367, ARTARMON. N.S. W. 2064 PHONE: SYDNEY 439-3378/4458 CABLES: PENNWALT SYDNEY