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abstracts for
4 Coastal & Island Mines

abstracts for 4.8 Northwest Territories, Labrador

Fallis, B.W. 1982. Trace Metals in Sediments and Biota from Strathcona Sound, N.W.T.; Nanisivik Marine Monitoring Programme,1974-1979. Canadian Technical Report of Fisheries and Aquatic Sciences No. 1082. Government of Canada, Fisheries and Oceans. 34pp. BOX: 20.

Abstract:

The development of the Nanisivik Mine resuited in the federal government initiating a programme to monitor changes in trace metal concentrations in sediments and biota in Strathcona Sound, NWT. The first set of post-operational samples since commencement of production at the mine in October, 1976 were collected in August, 1979. Analytical results indicate that concentrations of lead, zinc, cadmium and arsenic in sediments, seaweed (Fucus vesiculosus) and molluscs (Mya truncata) in tie vicinity of the marine terminal (station 3) have increased relative to pre-operational concentrations. Concentrations of lead, zinc and arsenic in sea urchins, (Strongylocentrotus droebachiensis), at station 3 have also increased; however, the post-operational cadmium concentration in sea urchins was slightly less than that recorded prior to production. Increases relative to pre-operational concentrations at station 3 were as follows: mean lead concentrations in sediments, Fucus and Mya rose by 56.0, 57.4 and 1.09 ug/g, respective, representing 3.8, 28.3 and 1.92 times pre-operational values, while the concentration in sea urchins rose from below the limit of detection to 23.9 ug/g. Mean zinc concentrations in sediments, Fucus, Strongylocentrotus and Mya rose by 595, 405, 213 and 283 ug/g respectively, equivalent to elevations of 4.8, 5.6, 4.3 and 3.7 times pre-operational values. Arsenic concentrations rose 5.4, 10.1, and 0.2 ug/g respectively in sediments, Fucus and Strongylocentrotus, equivalent to 2.4, 1.4 and 1.1 times pre-operational values, respectively.

Concentrations of lead, zinc, cadmium, arsenic and mercury in Serripes groenlandicus from station 3 increased 2.99, 97.4, 0.92, 4.32 and 0.11 ug/g, (19.7, 2.3, 1.9, 1.7 and 4.7 times) respectively, between 1975 and 1979. Metal concentrations in Cardium ciliatum also showed an increase at station 3 during the same time period with lead, zinc, cadmium, arsenic and mercury elevations of 0.37, 33.8, 218, 3.37 and 0.11 ug/g, equivalent to increases of 1.4, 1.7, 2.4, 1.7 and 2.2 times pre-operational levels, respectively.

Comparison of 1979 Fucus metal concentrations at stations 1 and 2 to Bohn's (1979) 1975 pre-operational concentrations at comparable stations, indicated highly significant differences (P<0.01) in cadmium and zinc concentrations at station 1 and a significant difference (P less-than-or-equal-to 0.05) in the concentration of zinc at station 2. Lack of pre-operational data from other stations in the Sound prevented assessing the extent to which trace metals in biota at other stations have changed. Analytical results from samples collected in subsequent years should provide an indication of the zone of influence resulting from trace metal inputs to Strathcona Sound.

Concentrations of lead and zinc in Strongylocentrotus and zinc concentrations in Mya in the vicinity of the marine terminal (station 3) currently exceed the maximum recommended levels (1.0 ug/g Pb, 100 ug/g Zn) for marine animal products established by the Canadian Food and Drug Directorate. Correlations between dry weight of soft tissues, shell height, width, and length and metal concentration in Mya truncata and dry weight, test height, width, and metal concentration in Strongylocentrotus droebachiensis, showed no consistent pattern with respect to the various stations sampled and thus prevented predictions of future concentrations which may be attained in these species. Continued inputs of trace metals to Strathcona Sound may result in elevation of biota concentrations to threshold levels at station 3 (and possibly other stations), beyond which further elevations will be less likely. The toxicological and physiological consequences of such threshold trace metal levels on biota in Strathcona Sound are unknown.

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Tester, F.J. 1974. Municipal Engineering in the Canadian Arctic: Strathcona Sound, A Case Study. Environmental Sciences Centre (Kananaskis) and The Faculty of Environmental Design, University of Calgary. 67pp. BOX: 20.

Abstract:

The Canadian north presents the municipal engineer with many special problems. In designing sewer and water Systems for the north, the municipal engineer must participate in overall community planning, the design of buildings for the Canadian north, and must play a meaningful role in the making of decisions which determine transportation and communication systems within isolated arctic communities. All of these concerns are significantly related to the eventual provision of water and sewer systems to northern communities. The municipal engineer must understand the costs of operating in the north, be aware of health problems which are created by a lack of adequate sanitary engineering, and must understand the concerns and attitudes of the native residents of the north. Above all, the municipal engineer must be acutely aware of the social, economic, and cultural impacts of transporting values based on southern living conditions to an environment where they are no longer appropriate.

The problems mentioned above are discussed in this manuscript. A proposed mining town which is being considered for Strathcona Sound, Baffin Island, North West Territories is used as a case study in order to concretely illustrate the points made, and in order to demonstrate the application of solutions to many of these problems. The intent is to orientate the municipal engineer to problems of engineering in the north. It is recommended that the municipal engineer familiarize himself with as many aspects of community planning and life in the north as possible in order that an integrated systematic approach to the problems of providing services to communities in the Canadian north can be made.

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Thomas, D.J. and S. Metikosh. 1984. The Effect of a Lead-Zinc Mining Operation on the Marine Environment of Strathcona Sound, N.W.T., Canada. 561-566. Environmental Contamination International Conference- London, July 1984. BOX: 20.

Abstract:

An oceanographic and biological sampling programme was conducted in 1982 to assess the effect of a lead-zinc mining operation on the marine environment of Strathcona Sound, a fjord located at the northern end of Baffin Island in Arctic Canada. The concentrations of lead and zinc were measured in sea water, sediments and the clam Mya truncata collected from the Sound; the highest concentrations occurred in the vicinity of the marine terminal at Nanisivik where lead and zinc concentrates are loaded onto ships. It was not possible, however, to assess the direct influence of the mining activities on the observed lead and zinc distributions in Strathcona Sound because Twin Lakes Creek, which flows past the ore body, enters Strathcona Sound at the loading dock and delivers significant amounts of Pb and Zn (from both natural and manmade sources) to the Sound. Biochemical measurements indicated no adverse effects in Mya truncata that could be related to their proximity to the creek mouth/marine terminal area. Three microscope techniques - scanning electron microscopy, light microscopy and interference microscopy - were appraised during the study as potential tools for detecting the presence of discrete particles of metal sulphides in marine sediment. Interference microscopy was judged to offer the greatest promise as a rapid, cost-effective method for mapping ore concentrate particles during routine geochemical reconnaissance surveys.

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Dobrocky SeaTech Ltd. 1974. Interim Report of the Hydrographic and Limnological Survey at Little Cornwallis Island, N.W.T. August, 1974. Submitted to BC Research Council. 45pp. BOX: 21.

Abstract:

Diver examination of the shallow marine areas near the Polaris mine-site and the outflow from Garrow lake indicated a rich and varied subtidal biota. The extensive clam population noted is apparently a significant food source for walrus, whilst seals and birds were also observed frequently in the same area. The deep water in Garrow Lake is exceedingly saline, very warm and high in sulphide content. The possibility of a geothermal source beneath the lake should be explored. The suitability of the lake as a tailings disposal site is now in question, and the feasibility of a marine disposal should be re-examined. Some recommendations for future water quality tests are presented.

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Dobrocky SeaTech Ltd. 1975. Report of the Hydrographic and Limnological Survey at Little Cornwallis island, N.W.T. August, 1974. Submitted to BC Research. 66pp. BOX: 21.

Abstract:

Diver examination of the shallow marine areas near the Polaris mine-site and the outflow from Garrow Lake indicated a rich and varied subtidal biota. The extensive clam population noted is apparently a significant food source for walrus, whilst seas and birds were also observed frequently in the same area. Some additional quantitative data on benthos can be extracted from underwater cine-film records taken by divers. The deep water below 10-20 meters in Garrow Lake is exceedingly saline, unusually warm and high in sulphide content. The ocean water in Cominco Bay showed temperatures within the range of typical values for the area and stream, and salinties slightly lower than typical. The metal content of sediment, shellfish nad water samples from Cominco Bay are presented. Zooplankton samples are held in storage for examination on request.

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Ellis, D.V. and J.L. Littlepage. 1974. Feasibility Study for Marine Disposal of Tailings at the Polaris Mine-site. Biology Department, University of Victoria. BOX: 21.

Conclusions:

  1. Marine disposal cannot be recommended in view of the alternative of apparently safe land disposal.
  2. Researchto generate information showing the pattern of dispersal of tailings after discharge to the sea would need further hydrographic surveys, field studies of current profiles throughout a full year, and model studies to simulate tailings disposal. The probable cost to obtain definitive information are great, probably in excess of several hundred thousand dollars. The most likely result would not support marine disposal. Therefore initiation of such research cannot be recommended.

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Ellis, D.V. and J.L. Littlepage. 1975. Re-assessment of Tailing Disposal to the Sea at Polaris Mine. A Report to Cominco Ltd. 25pp. BOX: 21.

Abstract:

Marine environmental data gathered in 1974 show expected oceanographic conditions and normal biological communities. Dense bivalve beds in shalow water in Cominco Bay are grazed by walrus. Controlled discharge of double cycloned tailing to a 140 ft depression in Cominco bay will smoher benthos in the main depositional area and produce a fringe area of light tailing. The expent and effect of this fringe area cannot presently be predicted and needs assessment by more detailed environmental studies. Resolution of environmental problems in the main depositional area may be resolvable by burying. Recommindations of further environmental assessment studies and routine effluent quality and receiving area monitoring are made.

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Ellis, D.V. and J.L. Littlepage. 1975. Re-assessment of Tailing Disposal to the Sea at the Polaris Mine; Consideration of the 1974 Environmental Reconnaissance Data. A Report to Cominco Ltd. 15pp. BOX: 21.

Abstract:

A marine disposal system for tailing now appears possible at the Polaris mine site, but may not be practical. Discussions on January 23 with mine staff prior to submission of details for a control and impact program to the regulatory agency should answer the remaining questions.

It appears unlikely that any system for marine disposal will be permitted if land disposal is practical, and Cominco must be prepared for a variety of suggestions to be put forward by the regulatory agency.

The marine system now considered requires Cominco to accept restraints on the discharge similar to those laid out by the Pollution Control Board of British Columbia for the mining industry but with additional restraints on particle size composition. These particle size restraints will be dependent on results of a current survey and laboratory studies to be undertaken in 1975. Cominco must also agree to operate a continuing program of marine environmental assessment, and to cover the deposited tailing if the assessment program indicates a developing environmental problem unacceptable to the regulatory agency. Such coverage may be acheivable in a number of ways.

Recommendations are made for the continuing environmental assessment program, but details will need agreement with the regulatory agency.

Recommendations are also made on a continuing environmental assessment program in Garrow Bay, which will be the receiving area for any overflow from the slime-receiving area of Garrow Lake.

Finally, Cominco is recommended to develop in-house capability for on-site supervision of the environmental program.

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Kuit, W.J. and J.K. Gowans. 1985. Tailings Disposal in an Arctic Environment. No Source. 15pp. BOX: 21.

Abstract:

The Polaris lead/zinc mine located on Little Cornwallis Island in Canada's high Arctic started production in November, 1981 and is the most northerly metal mining operation in the world. Both the remoteness of location and severe prevailing climatic conditions have required the implementation of several unique design, construction and operational measures in order to make it a viable enterprise. In addition, difficult constraints imposed on environmental planning necessitated innovative approaches, particularly with respect to the discharge of 1 500 t/d concentrator tailings. Sea and land disposal schemes were considered in the earlier stages of project development but were rejected on environmental and engineering grounds. The system selected and now in operation is based on the discharge of thickened tailings to the bottom zone of a meromictic lake which contains abundant hydrogen sulphide and has a salinity content about three times that of seawater. This paper provides a general overview of a highly interesting mining operation and focuses on the development and operation of an environmentally satisfactory tailings disposal system which is likely unique in the world.

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Anon. 1996. The Voisey's Bay Mine/Mill Project: Project Description Report. Voisey's Bay Nickel Company Limited. BOX: 21.

Abstract:

Voisey's Bay Nickel Company Ltd. (VBNC) is proposing to develop a nickel-copper-cobalt mine and mill (the "project") at Voisey's Bay, Labrador. The indicated mineral resource has been estimated at approximately 150 million tonnes. The life of the project is expected to be longer than 20 years. It is envisioned that approximately 500 persons will be employed throughout the operational life of the project.

The project is located in northern Labrador, 35 km southwest of Nain and 79 km northwest of Utshimassits (Davis Inlet). It is within an area subject to on-going aboriginal land rights negotiations. The climate is subarctic with short summers and long winters. The surrounding terrain is rugged, with elevations ranging to 400 m above sea level. Most of the project area is located in a sheltered north-south oriented valley connecting Anakalak Bay, to the north, with Voisey's Bay to the south. The valley is largely forested, while upland areas consist predominantly of barren rock.

The project includes open pit and underground mining operations, the construction and/or operation of storage and disposal areas for waste rock and overburden, site roads, an airstrip, a concentrator, a tallings impoundment area, an accommodations and services complex, a port site, maintenance and storage areas, a sewage treatment system, a power supply and distribution system and a water supply and distribution system. The ore deposit will be mined by conventional open pit and underground mining. The ore will be processed to nickel-cobalt and copper concentrates using conventional milling processes. The concentrate will be shipped to a smelter off site.

The project will be constructed and operated to manage environmental effects. Mine waste will be managed to minimize Acid Rock Drainage (ARD). The site will be reclaimed progressively during operations and upon cessation of the project.

VBNC has been conducting environmental baseline studies in anticipation of the requirement for an environmental assessment pursuant to the current statutory obligations.

This document has been prepared to support a referral by the federal Department of Fisheries and Oceans (DFO) to the Minister of Environment for the purpose of initiating the environmental assessment process. It has been anticipated that the DFO will be the Responsible Authority pursuant to CEAA and provisions under the Fisheries Act, due to the loss of aquatic habitat resulting from the infilling of the tailings basin and deposition of potentially acid generating rock under water. VBNC is fully prepared and committed to conduct a complete environmental assessment of the project.

The project has been subject to significant public interest, therefore, it is expected that it will be referred to the public hearing process.

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Ellis, D.V. and J.L. Littlepage. 1975. Projected Ecosystem Consequences Arising from the Discharge of Mine- Tailing to the Sea. From: Proceedings of the Circumpolar Conference on Northern Ecology. September 15-18, 1975, Ottawa. National Research Council of Canada. BOX: 21.

Abstract:

Three case-histories of mines discharging tailing to the sea in British Columbia are used to predict ecosystem consequences in northern seas. One mine discharges a regulated tailing slurry by a deep outfall to a threshold fjord and has had minimum ecosystem consequences. Another mine previously discharged an unregulated effluent to a similar threshold fjord and residual effects can be detected. The third mine discharged a regulated effluent to a waveswept sand platform, and some engineering and environmental problems developed. It appears that present effluent and outfall controls on the mining industry in British Columbia can substantially reduce ecosystem effects, predominantly benthic smothering and metal entry to food chains. Similar controls in northern seas would need to consider fine particle dispersal behaviour in "arctic" marine conditions, the feeding depths of benthic predators such as walrus, eider ducks, groundfish and prawns, and metal uptake patterns in northern species.

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abstracts for 4.9 Related Topics

Asmund, G. 1992. Pollution from the Marine Tailings Disposal at the Lead-Zinc Mine at Maarmorilik, West Greenland. pp. 587-594. In: Environmental Issues and Waste Management in Energy and Minerals Production. Edited by Singhal et al. Balkema, Rotterdam. BOX: 21.

Abstract:

Tailings from a lead zinc mine on the west coast of Greenland were disposed of in a fjord from 1973 to 1990. Between 10 and 30 t of lead, 30 and 55 t of zinc and 300 and 600 kg of cadmium dissolved per year, giving rise to environmental problems, especially with regard to lead. The dissolution process occured after discharge and before the settling of the tailings close to the outlet point. Further transport of dissolved heavy metals was mainly controlled by the winter mixing in the fjord that received the tailings and in connection with periods with large freshwater input to the fjord. In 1979 several changes of the tailings discharge system were made and at the same time the mining company improved their tailings quality. This led to an improved environmental situation. After the close down of the mine the tailings were left on the fjord bottom covering appr 0.6 km2. A year after the close down zinc was released from the tailings at a rate of 18-33 kg per day, lead release rates were from -1 to +0.5 kg per day.

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Asmund, G., J. Christophersen and J. Steensboe. 1990. Rehabilitation and Demolition after the Closure of the Zinc and Lead Mine 'Black Angel' at Maarmorilik, Greenland. Polartech '90. Proceedings ofthe International Conference on Development and Commercial Utilization of Technologies in Polar Regions 14-16 August 1990. Copenhagen, Denmark.16pp. BOX: 21.

Abstract:

On basis of a concession from 1971 production started at the "Black Angel" mine in 1973. The principles regarding clearance and environmental measures after the closure were established in 1968 in an addendum to the concession. The mining company reserves an amount at DKK 80 mill. for these purposes. The specific details for the clearance and environmental measures have afterwards been laid down by the Mineral Resources Administration.

One of the central purposes for the clearance and environmental measures is that the area within a period of a few years must as far as possible return to the environmental conditions as it was before the mining activities started.

All buildings, including the concentrator plant, power station, storage facilities, and apartment houses must be demolished. Before demolition the structures and areas polluted with ore or concentrates have to be cleaned. Unpolluted waste from the demolition has to be stored underground or on the site of the demolished concentrate storage building and covered by clean crushed rock.

Polluted waste and mineral waste from the cleaning must be stored in the mine and all accessible entrances closed in a safe manner. Toxic waste from oil, chemicals etc. must be shipped to reuse or destruction outside Greenland.

There are 4 main pollution sources after the closure:

  1. Dispersed metal rich minerals in the surrounding environment.
  2. Remains of ore and concentrate in the former industrial area.
  3. The tailings deposit at the bottom of the fjord.
  4. The waste rock dumps.

It is expected that item 1) and 3) will be of minor environmental significance after the closure. Item 2) is covered by the above mentioned cleaning of buildings and areas before demolition. Waste rock dumps will therefore be the largest pollution sources after the mine closure if nothing is done to abate the pollution. One of these dumps is placed environmentally most inconvenient partly on land and partly on shore. This dump will be required to be taken away from its present placing and dumped into Affarlikassaa fjord on top of the tailings deposit. Laboratory experiments have shown that the release of lead from waste rock deposited on the bottom of the fjord will be of minor significance. Other waste rock dumps, placed away from the action of sea water, are not, for the time being, planned to be removed.

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Asmund, G., M.M. Hansen and P. Johansen. 1988. Environmental Impact of Marine Tailings Disposal at the Lead-Zinc Mine at Maarmorilik, West Greenland. Proceedings of Conference on Control of Environmental Problems from Metal Mines. Roros, Norway, June 1988. 17pp. BOX: 21.

Abstract:

Tailings from a lead zinc mine on the west coast of Greenland are disposed of to a fjord. Approximately 6 t of lead, 12 t of zinc and 80 kg of cadmium dissolve per year, giving rise to environmental problems, especially for lead. The dissolution process happens after discharge and before the settling of the tailings close to the outlet point. Further transport of dissolved heavy metals is mainly controlled by the winter mixing in the fjord that receives the tailings. In 1979 several conditions were imposed on the tailings discharge system, and the mining company improved their tailings quality. This led to an improved environmental situation. Comparisons with lead zinc mines at Rana Fjord in Norway and at Nanisivik in arctic Canada show that only the tailings from Maarmorilik contain soluble lead compounds. It also appears that 90% of the lead in the Maarmorilik tailings are soluble in acetic acid.

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Grønlands Geologiske Undersøgelse og Grønlands Fiskeriundersøgelser. 1976. Recipientundersøgelse af Agfardlikavsâ, Qaumarujuk 1975-1976. (Recipient Investigation of Agfardlikavsâ and Qaumarujuk 1975-1976). In Danish with English Summary (pp. 109-111). 113pp., BOX: 21.

Summary:

This report illustrates a number of environmental aspects in Qaumarujuk and Agfardlikavsâ fjords, as experienced two years after permission was granted to Greenex to dump the tailings from the flotation plant in Mârmorilik into Agfardlikavsâ.

By the end of April 1976 the dumped tailings, mainly consisting of pyrites and calcite with minor amounts of sphalerite and galena, had reached the level of 1,050,000 metric tons. This amount is augmented monthly by about 35,000 metric tons. The dumping has had the effect that the bottom of Agfardlikavsa is covered with a varying thickness of tailings over its total area.

Hydrographic survey

As previously, the gradients of temperature, salinity, pH and oxygen content of the waters were determined, correlated with depth. Additionally, the oxygen content of the water layer immediately above the tailings were measured, in order to detect any oxidation of the sulphides.

As was expected, no immediate influence on the physical environment of the fjords by the mining operations was detected. Neither has any measurable decrease been observed of the oxygen content of the water layer in contact with the disposed tailings in Agfardlikavsâ.

The dissolved content of Pb, Zn, Cd, Cu and Hg in seawater

The content of these heavy meta1s disso1ved in seawater was determned under two different conditions: in open water and under the ice cover.

The analytical results confirmed last years observation that the contents of the heavy metals Pb, Zn and Cd are vastly increased in the top layer, immediately under the ice cover in the waters adjacent to the tailings disposal outlet, while the concentration drops appreciably in the upper 20 metres of the water column, when there is free tidal movement across the outlet shelf. However, the lower waters from 30 to 70 metres depth in Agfardlikavsâ are contamined throughout the year.

The Hg content, as expected, remained at its low natural level, as the ore does not contain appreciate amounts of mercury.

Benthos

No detectable change has occurred in the faunal population of the deeper parts of Qaumarujuk. However on more exposed sites near Mârmorilik, a notable decrease of the number of individuals of the benthic fauna has been observed. The benthos in Agfardhkavsâ has been severely affected by the increasing silting of the bottom by tailings.

The sampling technique employed has been shown to be inadequate to reach more precise conclusions as to the effects of tailings disposal. For this reason sampling in the future will be extended and the techniques even more standarized in order to increase the reliability of statistical appraisals.

Heavy metal content in biological tissue

The heavy metals, Ag, Cu, Fe, Ni, Pb, Zn, Cd, were determined in biological tissue with the aid of an optical spectrograph.

The Hg content was determined by means of atomic absorption spectroscopy. In mussels no essential change has been observed in the heavy metal content, as compared with the results for 1974, which showed a marked increase all along the coasts of both fjords when compared to the natural state before mining started. It seems that the mussel fauna has adjusted itself to a new increased equilibrium level.

Seaweed has been showed to be an excellent indicator for the gradual dispersion of the heavy metals released from the tailings or transported as dust - in this case, lead, zinc and cadmium. An increased level of zinc can be traced to a distance of 8.5 kilometres from Mârmorilik.

The influence of a general increased level of heavy metal pollutants in the benthos cannot be expected to be mirrored in the fish fauna after only two years, as factors other than purely environmental may overshadow the increased pollution.

Attention has mainly been focused on two species of fish, Greenland halibut and catfish. In general no marked change in heavy metal content of samples of muscle in these two species has been observed. A reexamination of the lead content in catfish liver has revealed a marked increase in 1975 compared to the two previous years, especially for catfish caught in Qaumarujuk in the weight group 1.5 to 2.4 kilograms.

Fish fauna

Fishing was carried out by means of shrimp trawl and longline. In the shrimp trawl catch no changes in terms of species composition and catch (e.g. number of individuals) were observed compared to similar fishing carried out before mining operations started.

In the longline catches no changes in species composition have been observed compared to the catches obtained before the mine started production. However the number of fish caught, especially of Greenland cod, has declined. lt is not clear whether this change is due to natural variation, the mine, or other factors.

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Grønlands Geologiske Undersøgelse og Grønlands Fiskeriundersøgelser. 1977. Recipientundersøgelse af Agfardlikavsâ, Qaumarujuk 1976-1977. (Recipient Investigation of Agfardlikavsâ and Qaumarujuk 1976-1977). In Danish with English Summary (pp. 127-130). 135pp., BOX: 21.

Summary:

"Recipientundersøgelse 1976-77, Agfardlikavsâ, Qaumarujuk" is a report in a series of yearly accounts of the environmental impact in the vincinity of the mining operations at Mârmorilik. It is especially concerned with the impact on the marine environment of tailings disposal in Agfardlikavsâ, in open connection with Qaumarujuk and for that reason with the whole fjord complex in Umanak district.

From the start of the mining operations in the autumn of 1973 until today some 1.5 million metric tons of tailings has been deposited into the sea. A number of heavy metal elements are thereby dispersed in larger quantity than is the case in natural weathering processes. This is in particular the case for zinc and lead, as the average content of these metals in the tailings is l.2% zinc and 0.4% lead, respectively. Moreover, about 20 ppm cadmium is dispersed in the tailings in close connection with zinc. The tailings additionally contain about 150 ppm arsenic and some 400 ppm copper. The heavy metal elements are contained in sulphides, which gradually dissolve in seawater.

Hydrographic surveys

Measurement of the gradients of temperature, salinity and pH with relation to depth below sealevel shows no discernible impact of the mining operations on the physical milieu of Qaumarujuk. The knowledge of these parametres, however, has practical implications for the evaluation of living conditions for organisms, and of the physical influence on the chemical parametres.

The content of lead, zinc, cadmium, copper and mercury in seawater.

Again this year the results of chemical analysis confirm previous observations, that the distribution of dissolved heavy metal elements is quite different whether the fjords are covered by ice or not. In March 1977 in Qaumarujuk it was found, that the dissolved heavy metals were primarily concentrated in the upper water-layer to 20 m below the ice cover. Previously it was found that the content of heavy metal elements in the water column of Qaumarujuk was distributed rather homogeneously. In March 1975, though, a marked maximum was observed at a depth of 30 m below sea level. In the open water situation, where the tides and the winds have free access, the content of heavy metal elements in the upper water layer of Qaumarujuk drops to low values. Normally the highest values in the water column are then observed at a depth of about 100 m below sea level.

In Agfardlikavsâ the content of dissolved zinc and lead is from 500 to 1000 ppb near the bottom the whole year round. Under ice cover this level is reached throughout the total water mass, but in open water the level drops to 5 ppb in the upper water layer of 20 m.

It is required to pay much attention to the consequences of the accumulation of heavy metal elements in the upper water layer in Qaumarujuk under ice cover. This obviously is due to the longlasting winter ice cover on the inner fjords during which water mixing almost ceases. Under those conditions the content of dissolved lead and zinc exceeds the recommended norms for sea water, as established in the United States. The polluted sea water is dispersed over a much wider area than anticipated, because no mixing occurs with sea water from below, and hence no dilution to a level which is acceptable for the environment.

The content of mercury and copper, both dissolved and in suspended matter in sea water is at a low level, as previously observed.

Bottom sediments

Monitoring the chemical composition of the bottom sediments in Qaumarujuk since 1972, particularly lead and zinc, shows that the heavy metal element content in the upper 2 cm of the sediment is slowly increasing. There are different opinions as to the cause. Partly it may be due to sulphide particle dispersion, either by airborne dust or by suspension in sea water, carrying the very fine fraction from the tailings in Agfardlikavsâ into Qaumarujuk. And in other part, dissolved heavy metal elements may be chemisorped by the naturally occurring mineral grains which are sedimenting the fjord.

Benthos

Many more samples were taken this year in order to provide a broader statistical base for appraising the state of the benthos as to number of species, number of individuals and its diversity. In Agfardlikavsâ, as observed in the previous year, the benthos is greatly reduced. In Qaumarujuk, no effects of mining activities on the benthos have yet been observed, except, possibly, that crustaceans are few in number of species and individuals. However, on the underwater sill between Agfardlikavsâ and Qaumarujuk changes in the benthos are observed which must be attributed to pollution.

Fish fauna

As in previous years longline and trawl fishing was carried out in Qaumarujuk. No change in the number of fish species has been observed since mining operations started. The trawl catches are at the same level or even larger than at the start of mining operations. Longline catches at first declined after tailings dumping commenced, but the decline was not continued in 1976/77.

Heavy metal element content in biological tissue

As before, chemical analyses of heavy metal elements have been carried out in biological tissue from seaweed and mussels, as well as liver and muscle tissue from spotted wolf-fish, Greenland halibut and Greenland cod. In seaweed and mussels in Qauma-rujuk, a increase of zinc has been observed. The mussel fauna in the outer part of Qaumarujuk is as contaminated with zinc as that in Agfardlikavsa which has reached a level of 35 ppm, double that in 1975.

Concurrently, cadmium in tissues is increasing. Lead has continuously increased in seaweed, but has been more or less constant in mussels since 1974.

The increase in lead content in the liver of spotted wolf-fish, already evident in 1975, is still continuing in samples taken in 1976 and 1977. To make sure that this can be attributed to only mining operations, and not to a simultaneous global dispersion of lead, catches were made in March 1977 in the vincinity of Umanak. The analytical results show a marked difference in lead content between the spotted wolf-fish caught near Umanak compared with those near Mârmorilik, which unambiguously establishes that the increase in lead in liver tissue is due solely to local pollution near Mârmorilik. The lead content in Greenland halibut liver and liver from Greenland codfish is also slowly increasing, on a lower level though. The other analysed heavy metal elements like zinc, cadmium, copper and nickel, have largely remained at previous levels, although some accumulation of cadmium in the liver of spotted wolf-fish is obvious. Muscle tissue, on the other hand, does not show the same tendency to accumulate heavy metal elements. There has not been observed any significant deviation from the levels as established previously.

In summary, it can be maintained that heavy metal dispersion, especially as to zinc, lead and cadmium, can clearly be traced in the stationary flora and fauna, being represented.

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Grønlands Geologiske Undersøgelse og Grønlands Fiskeriundersøgelser. 1979. Recipientundersøgelse af Agfardlikavsâ, Qaumarujuk 1977-1978. (Recipient Investigation of Agfardlikavsâ and Qaumarujuk 1977-1978). In Danish with English Summary (pp. 56-58). 61pp., BOX: 21.

Summary:

"Recipientundersøgelse 1977-78, Agfardlikavsâ, Qaumarujuk" is a report in a series of yearly accounts of the environmental impact in the vincinity of the mining operations at Marmorilik. It is especially concerned with the impact on the marine environment of tailings disposal in Agfardlikavsa, in open connection with Qaumarujuk and for that reason with the whole fjord complex in Umanak complex.

From the start of the mining operations in the autumn of 1973 until to-day some 1.9 million metric tons of tailings has been deposited into the sea. A number of heavy metal elements are thereby dispersed in larger quantity than is the case in natural weathering processes. This is in particular the case for zinc and lead, as the average content of these metals in the tailings is 1.2% zinc and 0.4% lead, respectively. Moreover, about 20 ppm cadmium is diepersed in the tailings close connection with zinc. The tailings additionally contain about 150 ppm arsenic and some 400 ppm copper. The heavy metal elements are contained in sulphides, which gradually dissolve in seawater.

Hydrographic survey

Temperature, salinity, oxygen content and pH gradients were measured in September 1977 at 7 stations in the fjord complex. In February 1978 only temperature and salinity profiles were determined, at 6 stations. As observed before, no measurable influence on the hydrographic situation around the mining town could be detected.

The content of lead, zinc, cadmium and copper in seawater

The observations on the distribution of these heavy metals in seawater in September 1977 and February 1977 has confirmed the seasonal variations, as previously reported, since 1974. However, in February 1978 it was noticed that the upper water layer, with increased lead and zinc concentrations, in contrast to the situation during the previous winter, had reached down to 50 metres below sealevel, instead of the usual 20-30 metres. The level of heavy metal concentration though was lower in February 1978 compared to March 1977. The lower water column, 30-40 metres above the bottom of Agfardlikavsa, was heavily polluted by heavy metal in solution, both in September 1977 and in February 1978, as generally has been the case in previous years. In February 1978 also the upper water layer of Agfard1ikavsâ was polluted by heavy metals, contrary to the situation in September 1977, when the level of heavy metal concentration was comparable to that of Qaumarujuk.

Bottom sediments

The gradual silting of Agfardlikavsâ with fine tailings is particularly noticeable at stations 1 and 2, which are situated at a relatively long distance from the tailings outlet. The results of chemical analyses from the upper 2 cm layer of the sediments at these stations vary from year to year, but generally show gradually increasing lead and zinc content, which shows inequilibrium in the outflow of fine tailings and the imput of particular matter carried by melt-water streams from the Inland ice. Analytical results, moreover, point to an irregular distribution of both the natural sedimentation products and fine tailings. Also at station 5, on the threshold between Agfardlikavsâ and Qaumarujuk, an irregular distribution of lead and zinc has been observed from year to year, which could be interpreted as being the result of bottom transportation of fine particulate matter over the threshold. At the same station the chemical analyses of groups of parallel samples taken at the same time may vary by a factor of 3, as has been observed previously. The analytical results of samples taken in 1977 show the same trend observed in 1975 and 1976 of a gradual slow accumulation of both lead and zinc on the total bottom area of Qaumarujuk. The increase is particularly taken place around the stations 13,14, 15 and 15A. Here also, no equilibrium is reached between the fine-grained lead and zinc-bearing solids and the naturally sedimented particulate matter. At station 16, however, the level of lead and zinc in the bottom sediments, has not increased since last year.

Heavy metal content in biological tissue

As has been the case in previous years, the content of silver, cadmium, nickel, iron, lead and zinc was determined in seaweed and mussels, as well as in the liver and muscle tissue from spotted wolffish and Greenland halibut, which also have been analyzed for mercury. It is observed that the copper, zinc and iron content in seaweed as well as in mussels has been at a constant level in the past three years in the whole fjord area, while the lead content increased steadily in Agfardlikavsa, as well as in the outer part of Qaumarujuk. The cadmium content is generally below the detection limit of 0.4 ppm, but can be as high as 1.4 ppm in both seaweed and mussels.

The continuing observations on spotted wolf-fish and Greenland halibut have shown that the trace element content in muscle tissue of these two spicies has not changed since mining began. In liver tissue from spotted wolf-fish, the lead content has been rather constant in the past three years, although significantly higher than the background values found in liver tissue samples analyzed before mining was started, or in samples from spotted wolf-fish caught near the township of Umanak. There appears to be a tendency for the lead content in liver tissue from spotted wolf-fish with a weight of less than 2.7 kg to be higher than that in similar tissue from bigger fish. With respect to the remaining trace elements, no change in content has been observed in liver tissue. With mercury, however, it is noticed that there is a slight tendency to increase in muscle tissue from spotted wolf-fish, as compared to analytical results from the period 1974-76. As to the other tissue samples, muscle from Greenland halibut and liver from spotted wolf-fish, no change has been noted since observations were initiated in 1974.

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Møller, J.S. 1984. Hydrodynamics of an Arctic Fjord. Field Study, Affarlikassaa, West Greenland. Resonance of Internal Seiches and Buoyancy-Driven Circulation. Institute of Hydrodynamics and Hydraulic Engineering. Technical University of Denmark. Series Paper 34. 197pp. BOX: 21.

Summary:

A comprehensive field measurement programme in an Arctic fjord is reported. The fjord, Affarlikassas, is a small sill fjord (length 4 km, width 500 m, maximum depth 70 m, sill depth 21 m ) with a simple topography. The fjord is connected with the West Greenlandic Uummannaq fjord system by the larger fjord Qasmarujuk. The fjord is ice-covered from December to June, and it is stratified most of the year due to fresh water input during the summer. The measurements were carried out during the period September 1981 to September 1983. Automatic recording instruments recording current, salinity and temperature were used.

On the basis of these data, and the data previously collected by other institutions, a descriptionof the hydrography of the fjord is given. Special consideration is given to the transport mechanisms for the bottom layer water of the fjord and the flow conditions under ice cover. The existence of tidal-generated internal seiches is demonstrated. The existence of buoyancy-driven circulation due to salt rejection from the growing sea ice is demonstrated. pollution transport is discussed, and it is shown that long term several years variations in the hydrography of the outer fjord system govern the present mixing conditions of the fjord.

The tidal-generated internal seiches are described by an analytical mathematical model. It is shown how resonance of the seiche will occur during the autumn. The mixing efficiency of the seiche is investigated, and it is shown that the mixing effects of the seiche are small compared with the other mixing processes present in the fjord.

The buoyancy-driven circulation is described by a two-layer analytical model. The governing equations are integrated over the layer depths, and a constant densimetric Froude number for the flow is assumed. The model is verified by the field measurements and by a series of laboratory experiments conducted at ISVA.

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Vandkvalitetsinstituttet. 1974. Recipientundersøgelse, juli 1973, Qaumarujuk Fjord, Agfardlikavsâ. (Recipient Investigation of Qaumarujuk and Agfardlikavsâ August 1973). In Danish with English Resume. 169pp., BOX: 21.

Summary:

The investigations carried out in July 1973 in Qaumarujuk and Agfardlikavsa were a continuation of the investigations initiated in 1972 by the Institute for Water Quality.

The purpose of the investigation were to describe: the tide, plant and animal life and heavy metal concentrations in water, sediment, plants and animals in the unaffected fjord system.

The 1973 investigations intended to extend and improve the knowledge of the original state of nature before discharge of tailings was initiated in August 1973.

The investigations were planned and carried out in co-operation with the GFU, the GGU and the VKI-staff.

The investigation in the area took place in July 1973, and working up of the material collected during 1973-74.

The investigations included hydrographic measurements, water analyses sediment and biological material for heavy metals. The bottom and the fish fauna have been described on the basis of the collected bottom samples and on yield with trawl and longline.

The investigations proved:

The main conclusion from two years' investigations is that the natural heavy metal content in water, sediment, animals, and plants do not differ substantially form the heavy metal content to be found at corresponding investigations in the north-atlantic area.

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Coles, S.L. 1977. Marine Management and the Siting of Electrical Generating Stations on Tropical Shorelines. Marine Research in Indonesia 19: 52-71. BOX: 21.

Abstract:

Expanding utilization of electricity by developing tropical nations will produce increasing amounts of waste heat that will, in most cases, be disposed into natural water systems. Such disposal represents a serious potential marine management problem for nations which intensively utilize the nearshore marine environment in their subsistence economy. This communication reviews the marine environmental effects resulting from thermal disposal at three generating stations on the Island of Oahu, Hawaii and compares these with results of similar studies made elsewhere in the tropics and subtropics. Conclusions are drawn from these studies concerning desirable environmental features to be considered for thermal outfalls in tropical areas, and some environmental consequences of alternative methods of cooling water treatment are discussed.

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Coles, S.L. 1982. Guidelines and Environmental Considerations for Siting Power Stations in Tropical Areas. Submitted to the GESAMP Working Groupon the Biological Effects of Thermal Discharges, FAO, United Nations. 23pp. BOX: 21.

Abstract:

Once-through circulation of cooling water is proposed to be the most economic and energy efficient method for removing waste heat from the condensers of steam-electric generating plants. The environmental effects from using water from marine and estuarine systems have been shown to generally be non-detrimental to organisms resident in receiving waters provided that reasonable precautions are taken in plant design to protect the aquatic environment. Such precautions are particularly important in tropical areas, where marine organisms normally live at temperatures much closer to their upper tolerance limits than their temperate counterparts.

A number of case studies are presented which describe environmental problems that have resulted from thermal discharge in tropical and subtropical areas. The information gained from these examples is used in developing guidelines and desirable characteristics for siting power stations in tropical and sub-tropical areas.

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Coles, S.L. 1984. Colonization of Hawaiian Reef Corals on New and Denuded Substrata in the Vicinity of a Hawaiian Power Station. Coral Reefs 3: 123-130. BOX: 21.

Abstract:

The colonization and growth of reef corals settling on new substata (concrete and basalt) and on a denuded coral reef were studied over a seven-year period. The study area is in the vicinity of an outfall discharging thermal effluent from a Hawaiian power station, and both numbers and coverage of settled corals were found to increase exponentially with proximity to the outfall's discharge. Recruitment rates adjacent to the outfall were at least ten times greater than values previously reported for open ocean areas in Hawaii, and the estimated time for recovery of the coral community near the outfall was comparable to the most rapid that has been reported worldwide. By contrast, coral recruitment and recovery more distant from the outfall compared well with slower rates reported for other areas in Hawaii. Entrainment of coral planulae in water discharged into the area by the outfall is proposed to be the principal mechanism promoting the high coral colonization.

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McCain, J.C., S.L. Coles and J.M. Peck. 1975. The Marine Biological Impact of the Honolulu Generating Station. Sea Grant Technical Report UNIHI-SEAGRANT-TR-76-01. 50pp. BOX: 21.

Abstract:

Studies of the effects of the Hawaiian Electric Generating Station on the zooplankton, reef corals, and fishes of Honolulu Harbor, Oahu, Hawaii were made during 1972-73. No distinct detrimental effects attributable to the generating station were revealed by these studies. The macrozooplankton community in the outfall basin more closely resembled communities sampled outside the harbor than elsewhere in the harbor, which receives a variety of pollutants Differences in distribution and abundance of macrozooplankton were more closely related to depth and temporal differences than to power station discharge. Although reef corals were restricted from the wall directly in the path of the outfall jet plume, the total coverage of live corals in the discharge basin exceeded that of the intake basin and discharge basin coral colonies were generally larger. Negligible coral growth was found anywhere else in the harbor. Fish standing crop in the discharge basin was estimated to be approximately twice that of the intake basin and little movement was noted between the two areas. Standing crop in both basins was generally higher than estimates for tropical and subtropical shallow water areas. No clear comparisons were possible concerning weight per unit length of fishes in the intake versus discharge basins.

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Carey, J.E., M.A. Pettit, W.S. Rooney and T.L. Judell. ND. Baseline Studies and Continuous Monitoring for a Shallow Tropical Bay Receiving Nickel Refinery Effluent. No Source. 11pp. BOX: 21.

Abstract:

Pre-discharge baseline studies and a long-term post discharge surveillance program have been undertaken in order to monitor any effect of nickel refinery effluent on the coastal waters of Halifax Bay, Queensland, Australia. Short-term toxicity studies were conducted as a basis for determining the maximum limit of ammonia, the principal toxicant. Physical and chemical characteristics of seawater and substrates, chlorophyll a concentrations, zooplankton populations and the benthic invertebrate community have been monitored for eight years. These studies have indicated that the receiving waters, which were initially nitrogen-deficient, have been locally enriched in ammonium-nitrogen. No adverse effects on the marine ecology have been detected. The diversity and abundance of the benthic invertebrates have been maintained. Marginal changes in composition and structure of the benthic invertebrate community, in chlorophyll a concentration and zooplankton density and biomass, appear unrelated to effluent discharge. It is considered that effective long-term biological monitoring requires a firmer theoretical foundation than is presenrly offered in the stability-diversity hypothesis and that this can only be attained by wider dissemination of available data.

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Hildebrand, L.P. 1984. An Assessment of Environmental Quality in the Baie des Chaleurs. Environmental Protection Service Report Series EPS-5-AR-84-8. 191pp. BOX: 21.

Abstract:

This report represents an overview of the available information relevant to the environmental quality of the Baie des Chaleurs. It was prepared in response to a need to assess the pollution sources and effects in the Bay, to evaluate their impact on environmental quality and to document the success of control efforts.

The report proceeds by discussing major sub-watersheds and associated coastal zones of the Bay. It discusses, where information was available, each industry, its contribution of effluents and emissions, resultant impacts on the receiving environment, the control efforts, and improvements over the last ten years. Levels of contaminants in atmospheric, aquatic and terrestrial components are discussed.

The emphasis lies on the improvements in the period between the early 1970's and early 1980's. The report concludes by identifying areas where continued efforts are warranted.

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Judell Platt Thomas & Associates. 1989. Consideration of Importation of Nickel Ores Via Halifax Bay with Respect to Effects Upon the Marine Ecosystem. Dallhold Nickel Management Pty. Ltd. Report. 27pp. BOX: 21.

Summary:

In this report, impacts upon the marine ecosystem of proposed operations associated with the transportation of nickel ores to the Yabulti nickel refinery via Halifax Bay, are discussed.

Possible effects of spillage of ores into the sea have been studied and water quality criteria upon which standards should be based in order to prevent adverse changes in the marine ecosystem are described.

Investigations into the nature of solubilities in sea water of metallic constituents of imported ores from three mines have been carried out.

Effects of trace metals upon marine ecosystems are discussed and effects of the leaching by seawater of ores which may be spilled from ships and shuttles during unloading and handling operations have been investigated.

Occurrences of nickel ore sediments in New Caledonia arising from the deposition there of residues from nickel ore mining and erosion have been studied. The nature and results of these investigations are described and their implications are discussed.

Programmes for monitoring of trace metals, fuel oil, suspended solids and turbidity involving water columns, sediments and biota are proposed, based on water quality criteria developed by the United States Environmental Protection Agency.

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Reid, J.G. 1978. Metallurgical Operations at the Yabulu Nickel Refinery of Queensland Nickel Pty. Ltd. The Aus. I.M.M. Conference, North Queensland, September, 1978: 347-354. BOX: 21.

Abstract:

Geologists employed by Metals Exploration Pty. Ltd. discovered nickel enrichment at Greenvale, 180 kilometres West of Townsville, in 1967. Subsequent drilling proved an ore body containing 45 million dry tonnes of ore containing an average of 1.5% nickel and 0.11% cobalt.

The Freeport Minerals Company, who had experience in treating lateritic nickel ore, were invited to participate in development of the ore body. This resulted in the formation of the operating company Queensland Nickel Pty. Ltd., jointly owned by Freeport Queensland Nickel Inc. and Metals Exploration Queensland Pty. Ltd.

With the completion of successful pilot plant testing of Greenvale ore at the Freeport research facilities at Belle Chasse, Louisiana, a treatment plant was constructed at Yabulu, 24 kilometres North West of Townsville. A 225 kilometre railway line was built connecting the Greenvale line and Yabulu Treatment Plant.

The ore reduction and ammonia/ammonium carbonate leaching flowsheet is similar to that constructed and operated by the Freeport Minerals Company during World War II at Nicaros Cuba. Modifications to the Nicaro flowsheet implemented at Yabulu include facilities to recover cobalt in a mined nickel/cobalt sulphide product and the reduction of nickel oxide calcine with hydrogen gas.

This paper describes the stages of treatment required to produce nickel oxide products and a mixed nickel/cobalt sulphide product at Yabulu.

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Whyte, A.V. ND. The Role of Information and Communication in the Regulation of Emissions from a Heavy Metal Smelter: The case of Avonmouth. No Source: 111-127. BOX: 21.

Abstract:

The paper reports upon an empirical investigation of information flows and the pattern of communication between experts, government officials, company management, the media and the general public, in the pollution incident which occured at the R.T.Z. lead, zinc and cadmium smelter at Avonmouth, near Bristol, England in 1972.

The study describes the impact of information on public awareness and analyzes communication flow in terms of a) the characteristics of the "sender", b) the perceived characteristics of the "receiver", c) the relationships between "senders" and "receivers" and d) the types of message.

The role of these communication flows is shown to be important in public perception of government action and shaping the activities of "action groups". Governmental response to heavy metal pollution can be understood in terms of an information model. Changes in the information and communication process would, if adopted, alter significantly the public perception and appreciation of government regulatory decisions.

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Newell, P.F., R.C. Newell and M.W. Trett. 1990. Environmental Impact of an Acid-Iron Effluent on Macrobenthic and Meiofaunal Assemblages of the St. Lawrence River. The Science of the Total Environment 97/98: 771-781. BOX: 22.

Abstract:

A method for the quantitative extraction of the macrofauna, small invertebrates and meiofauna from sediments is described. The large variety of organisms obtained by this method allows sensitive analyses of assemblage structure in relation to the discharge of an acid-iron effluent from Tioxide Canada Inc. at Tracy, Quebec. Group average sorting and multidimensional scaling (MDS) techniques suggest that the effluent results in the formation of a modified benthic assemblage corresponding with the zone of dispersion of the wastes. Assemblages in the surrounding sediments are, however, rich and diverse, comprising a total of 73 taxa of macrofauna and small invertebrates and 86 taxa of meiofauna (mainly nematodes and copepods).

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Newell, R.C., P.F. Newell and M.W. Trett. 1990. Assessment of the Impact of Liquid Wastes on Benthic Invertebrate Assemblages. The Science of the Total Environment 97/98: 855-867. BOX: 22.

Abstract:

Modified assemblages corresponding with the zone of dispersion of acid-iron effluents from the manufacture of titanium oxide pigments in a range of marine and freshwater receiving waters have been identified in tropical and temperate climates. The findings of these studies over several years are reviewed using a wide range of examples. The methodology used for the collection and extraction of the macrofauna, small invertebrates and meiofauna is described. Multivariate analytical techniques used to identify and delineate impact zones are illustrated and the high resolution attributed to the detailed examination of the meiofauna. The shape of such impact zones is dependent, among other factors, on the strength and direction of current flow. Although the sediments in the impact zones which we have studied are not abiotic, their assemblages tend to be characterized by a reduced species richness and a corresponding increase in abundance of resistant species. Results from one of these detailed surveys (Calais), over a 5 year period, indicate that the impact zone is remarkably stable and occupies a similar area in successive years. Disposal of these anthropogenic wastes thus appears to modify assemblage structure in a way which is essentially similar to that imposed by natural stress factors.

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Bourcier, M. and M. Zibrowius. 1973. Les "Boues Rouges" Déversées dans le Canyon de la Cassidaigne (region de Marseille): Observations ensoucoupe plongeante SP 350 (juin 1971) et résultats de dragages. Tethys 4 (4): 811-842. BOX: 22.

Summary:

The "red mud" discharged into the submarine canyon of Cassidaigne (near Marseilles). Observations from the diving saucer SP 350 (June 1971) and dredging results.

For several years aluminum plants in the Marseilles area have been discharging mineral residues (fine red coloured fluid mud) from the alkaline treatment of bauxite into the submarine canyon of Cassidaigne. This is done by means of two pipes ending 3,5 miles offshore at depths of 320 and 330 m. When in contact with seawater, soluble soda quickly reacts, precipitating magnesium hydroxyde. The greater part of the red mud forms a density current and spreads in the central deeper part of the canyon. There the macrobenthic specics are eliminated by the mechanic effect of the thick fluid layer of deposited mud. There is no intoxication of the marine biota, the mud particles being inert unsoluble oxides mainly of iron, aluminium and siIicon. In the more peripheric zones of the canyon with thinner deposits of red mud (a few mm to cm) animal life appears normal and undisturbed. Through animal activity the red mud becomes mixed up and integrated with the natural muddy sediment found at these depths. In the more peripheric zones suspension feeders as well as species feeding on sediment and various kinds of fish are prosperous and appear unaffected by the presence of red mud.

Particles of red mud are incoporated into various Polychaete tubes, including calcareous tubes of Serpulidae. Red mud annulations spaced out on Serpulid tubes are best explained by dense suspensions of red mud particles passing by episodically when currents in the deeper part of the canyon are modified by storms. Exceptional currents are responsible, too, for lifting up a small part of the discharged red mud to the border of the shelf (about 110 to 120 m) on the western side of the canyon.

The discharge of the red mud under the conditions described cannot be considered as a major disturbence, by pollution, of the marine ecosystem in the Marseilles area.

Observations and samples taken from the diving saucer while surveying the red mud, together with dredging results from the same area, contribute to a betler knowledge of the deeper benthic fauna in the Marseilles area. Various species new for the Marseilles area, the Northern Mediterranean, or even unknown in the Mediterranean have been observed or collected for the first time. Special attention is paid to the depth distribution of Madrepora oculata. Previously considered as the principal species of a bathyalbiocoenosis in the Mediterranean ("white corals"), M. oculata appears common on the westernborder of the canyon of Cassidaigne, associated with Corallium rubrum at depths of only 130 to 150 m.

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Mining Journal Research Services. 1996. Environmental and Safety Incidents Concerning Tailings Dams at Mines: Results of a Survey for the Years 1980-1996. Report Prepared for United Nations Environment Programme and Joint UNEP/ DHA Environment Unit. 51 pp. and Appendices. BOX 22.

Synopsis:

The tonnage of mine tailings generated around the world each year is very large. For example world copper production in 1995 resulted of l,5OO Mt of tailings, while gold output generated 500 Mt. 120 Mt of tailings from potash mining were produced.

The collation of data concerning tailings dams remains with individual agencies, with wide variation in the amount and quality of information held. Accordingly, it is rarely possible to estimate the true population of impoundments nationally, or world-wide. As a guide respondents reported 350 tailings dams in the State of Western Australia and 164 in the Canadian province of Quebec. For the Republic of South Africa, the estimate is of the order of 400.

Tailing darn embankments are typically (but rot universally) constructed from non-cohesive materials such as cycloned tailings, earthfill or waste rock, all of which can be easily eroded by water. Failure of decant systems, spillways and diversion conduits is a major factor in smaller incidents. Inadequately sized spillway or decant systems can also lead to wall failure.

An area for concern continues to be inadequate supervision of construction as noted by theNew South Wales Mine Inspectorate: "In regard to the construction of tailings dams we are concerned that while their design may be adequate their construction may not be to specifications; construction is often performed other than by the designer".

Most failures occur as a result of percolation through the dam wall, internal erosion, overtopping or flooding and may be triggered by natural phenomena such as earthquakes or persistent heavy rain. Incidents from uncontrolled seepage have become more common with the increased use of cyanide in the recovery of gold, in all parts of the world. Dust emissions can also present localised nuisance, such as dust blowing from the Kilembe tailings dams and pyrite stockpiles in Uganda, and the cadmium contamination that is emitted from Chinese tungsten mine waste. Bird kills from cyanide are increasingly reported. Fortunately large scale incidents are infrequent. This study identified fewer than ten major failures between 1980 and 1996.

Greater importance should be attached to relocation of communities that have a risk of inundation should a tailings dam fail. The fact that the largest number of casualties recorded within the study period were sustained by the general population and not mining company workers directly, underscores the potential vulnerability of these people.

Overall, the level of public reporting of major failures is very variable. There is no centralised source of information about tailings dam incidents, either internationally or for the most part, nationally.

The study concludes that tailings dams are a necessary constituent of modern mining practice. Incidents of varying degrees of severity have occurred in the past, and probably will in the future. The task ahead is to ensure that the risk of major incidents is minimised, and that also environmental impacts be given greater attention. Improvements in design, construction and operating practice will assist in achieving this, requirements increasingly being stipulated in the relevant regulations.

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Various. 1997. Proceedings of the International Workshop on Managing the Risks of Tailings Disposal. May 22-23, 1997, Stockholm, Sweden. 257 pp. BOX 22.

Executive Summary:

Tailings are the sand-like residues that remain after the valuable minerals have been extracted from an ore. For most non-ferrous metal mines, the tonnage of tailings is roughly the same as the volume of ore treated. Large impoundments, frequently called tailings ponds, are built to contain this waste material and to provide a catchment area for process water. Tailings can have a number of chemical and physical characteristics that may pose risks to people and to the environment. The workshop indicated that the tools to enable safe design, operation and closure of tailings impoundments are available, but they must be properly used arid managed.

The workshop pointed to the need for promotion of best practices, particularly among small- and medium-sized companies; the use of risk assessment as a basis for decisions in the siting, design and operations of tailings disposal systems; improved communication of technical and risk information; on emergency preparedness with the various interested parties including communities; and, enhanced cooperation between operating companies and regulators to make better use of the capacity of both sectors. Good practice not only addresses design, construction and operations, but eventual closure and subsequent land use.

The existence of design codes and standards does not prevent tailings impoundment incidents and failures. In most cases, tailings impoundment areas continually change as new material is added during the operation of a mine. The technical issues related to this evolutionary nature of tailings construction are not always appreciated. Lessons learned from past incidents are not always kept in mind.Nations aspire to have the sound institutional arrangements necessary for ensuring that the public interest with respect to safety and the environment is addressed. Income from mining can represent the most significant source of export earnings for some developing countries, however, such countries may not have the most effective regulatory regimes. Some governments lack technical expertise and administrative capacity to properly regulate. Only in the event of a disaster do issues gain sufficient attention to demand improved regulations.

There is a need for increasing attention by all parties. It was suggested that tailings issues are sometimes low on the corporate priority list and that, on occasion, lower cost options are chosen over the most environmentally sound and safety-oriented approaches. However, milling companies are vulnerable to business interruption and considerable cost in the event of tailings dam incidents. Furthermore, industry's reputation is judged on the behaviour of the weakest performer. Governments face public pressure to increase control over mining operations, while their capacity to do so is declining. It has been suggested that trust plus control equals a constant (T + C = K). Both industry and governments can benefit from increasing trust. The key is to find ways to develop and enhance that trust. This demands early and close cooperation arid coordination of the efforts of both operators and regulators.

The tools to achieve high levels of safety and reliability are available. Industry must make full and effective use of these tools. The use of risk assessment methodologies to evaluate risks and the application of total quality management approaches in planning, design, construction, operation, monitoring and closure are seen as key to safety and environmental protection. The Hazard Rating system employed in Western Australia is an example of the use of the risk assessment methods. Risk assessment provides a framework for consideration of all of the risks associated with tailings dams. It is an enabling mechanism to assess the trade-offs between reliability and affordability and allows for more informed and better balanced decision making. Such trade-offs include socio-economic and ecological considerations.

Environmental management systems are seen as a major step in improving the appropriate use of both technology and human resources. Such systems call for management leadership of employees who are aware, trained, competent and informed. The elements or good planning, excellent performance, continuous review and effective corrective action enable appropriate management of risks. Industry initiatives in applying total quality management to design, construct on, operations, inspection, monitoring, water conservation, pollution prevention and emergency preparedness will enhance the level of trust. Not only must plans be in place, but they must be demonstrated through testing that they in fact work. With such assurances, consideration may be given to a system of co-regulation based on sound communications, effective collaboration and mutual trust.

Conclusions

Two discussion panels were assembled to compile the conclusions and recommendations. The first panel addressed the question of what the regulatory climate in the future will likely comprise. The second panel addressed the challenges to both industry and regulators in meeting the expectations of the public in terms of the protection of health, safety and the environment related to tailings disposal systems. To facilitate this process, each participant was asked to complete a questionnaire identifying aspects of the workshop that most impressed or were lacking, what the follow-up should be and what messages should be delivered to companies, governments and associated organizations. Responses were addressed in the final discussions and are reflected in the Section entitled A Path Forward.

Regulatory Trends

Despite marked improvements in tailings disposal practices on the part of the large commercial mining companies, public concern has not diminished. Developing countries would like to have prescriptive codes and regulations to guide in the evaluation of new mining projects: They would like to call upon international standards such as have been developed by the International Commission on Large Dams (ICOLD). However, they lack the skills and capacity to enforce rigid control regimes. A more flexible approach would be ideal, but one that has some basis for enforcement, should the commitments not be kept. Some mechanism of financial assurance or performance bonding might provide the required backup in the case of non-performance as an alternative to stiff penalties. Developed countries are trying to introduce higher levels of training and accountability in tailings dam management. Tax incentives for using sound pollution control facilities and awards for high levels of performance may prove to be effective. Industry is taking the initiative to develop its own standards, being promulgated via workshops and peer pressure, that could result in regulators following this industry lead rather than reacting to the latest event. The operative word that seemed to arise was co-regulation.

A Path Forward

The following issues and messages were central to the closing panel discussions:

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