Painless extraction? Mining and water-resource protectionby Oliver Carr

Discharge of arsenic-contaminated water from a goLd-mine taiLings Lagoon into ariver in south-west Ghana.

Mining brings jobs to rural areas, but theimmediate and long-term environmental costscan be high. Can project planners put into placeassessment and monitoring systems to preventpermanent damage to local water resources?

THE PROTECTION AND manage-ment of water resources during theconstruction and implementation ofmining projects can make a substantialdifference to people living in or near tomining concessions. Effective planningis an essential process to ensure waterresources are considered to an appro-priate level and to protect local peopleand their interests. All too often in thepast, the people planning mining oper-ations have not fully considered envi-ronmental issues, which has led todegradation of resource quality and,sometimes, long-term adverse eco-nomic and social effects.

Mining in south-westGhanaThe management and minimizationof adverse effects in every projectphase in order to protect fully localpeople must be included in any project-planning exercise. Environmentalimpact assessment (EIA) provides aneffective opportunity for an examina-tion of water resources to assess andmanage the implications of a miningproject at birth, and forms the basisfor on-going management throughoutthe project's life. This article recountsthe experience gained by environmen-tal consultants SGS Environmentduring environmental assessmentfor several mining projects insouth-west Ghana.

In recent years, Ghana's miningindustry has expanded considerably;the Government has recognized thepotential adverse environmental effectsand has introduced regulationsdemanding an EIA before operationstart-up. An important part of any envi-ronmental assessment is ensuringappropriate water-resource manage-ment, together with the protection oflocal people. Many of the mines insouth-west Ghana are located in rela-tively well-populated areas previouslyused as mixed forest and agriculturalland, although local people mine therivers extensively for gold. Water

resources are used for drinking andwashing, as habitat for fisheries, andfor transport; they also have religioussignificance. In addition, the rain-forests of the area can form importantcomponents of catchment hydrologyfor water-resource management.

SurveysIn order to understand fully how a min-ing project might affect waterresources, a thorough examination ofthe resources and their uses is needed.This involves carrying out surveys ofwater resources, including an assess-ment of resource quality and uses. Thevalue of the resources is then exam-ined, enabling evaluators to grasp fullythe project's significance. This evalua-tion requires specialist understandingof the environment under considera-tion; standards and guidelines, such asthose on water quality issued by theWorld Health Organization - andcomparisons with experiences in otherareas - will help.

SGS Environment found that, in therural areas chosen for new sites, local

people generally used either surfacewaters or shallow wells for their drink-ing- and washing-water supply; waterwas frequently of poor quality. Theshallow wells were frequently contami-nated by overland flow of water, andthe surface waters were polluted byfaecal wastes, and from small-scalegold excavations. Local people searchfor gold deposits in river gravels in andaround the rivers; this causes high lev-els of suspended solids and pollutionby the mercury used in gold process-ing. Some of the more accessible vil-lages had piped water supplies, mostlyof good quality, although, in somecases, iron contamination reduced itssuitability both for drinking andclothes-washing.

Diet and healthUse of the local water bodies for fish-eries was found to be important, asfreshwater fish is an essential source ofprotein in the local diet, although mostof it is sea fish bought at the market.The types of fish vary; from migratoryspecies, to those found all year in tribu-taries, and species which live and breedin swamp habitats. The maintenance ofthe living and breeding habitats forfish, and pathways between tributaries,swamps, and the main rivers and fish-ing sites, therefore, was important.

Water also influences local people'shealth, with many diseases being

WATERLINES VOL. 14 NO.1 JULY 1995 19

Gold-diggers in Brazil: they may take away with them more than just gold.

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related directly either to water quality,or to the presence of disease vectors inaquatic habitats. The investigationsshowed that significant diseases in thearea ranged from diarrhoea in faecal-contaminated drinking-water tomalaria, bilharzia, river blindness, andguineaworm.

The effects of mining projects can beconsiderable. Both direct and indirecteffects can lead to the loss or reductionin resource quality. Direct effects aredefined as changes caused by the pro-ject, such as land-take. Indirect effectsare more difficult to assess, and arise asa result of 'remote' factors; for exam-ple, from the movement of peoplewhich can result in increased resource-use, and a deterioration in quality.Environmental assessments should beintegrated so that indirect effects, suchas socio-economic changes, are fullyassessed. The assessment must alsotake into account likely future changeswhich could influence water resources,and the combined effects of other exist-ing projects.

Environmental impactsThe major direct effect of any miningproject is the loss of, or alteration to,surface waters as a result of land-take.This can cause a reduction in the avail-

ability of drinking- and washing-water,for example, from water abstraction;changes to catchment-hydrologythrough the loss of rainforest and occu-pation of sites traditionally used fordrinking-water or washing; the reduc-tion of the fisheries potential of an areaby loss of habitat for reproduction andfishing locations, interruption to migra-tion pathways, and loss of fishing sites.A further, serious potential impact inthe humid tropics is the likelihood ofthe fast-increasing number of sites,such as pools, for the growth of diseasevectors such as mosquitoes.

Mining can also cause changes towater quality; from excavation activi-ties (with de-watering and drainagewater, for example), with increasedlevels of suspended solids and solubleminerals, the accidental release of oils,sewage from the work camps, andeffluents from mineral-processingactivities. Gold miners use a numberof methods to process the gold ore,some of which use potentially haz-ardous chemicals, such as cyanide. Inaddition, other dangerous chemicals,such as arsenic compounds, may bepresent in some of the gold oresreleased during processing. Since thesecompounds have the potential to causesubstantial environmental damage, andpose a serious threat to people, strict

controls are essential. Any suchchanges in the quality of waterresources - surface or groundwaters- can have implications for the use ofwater resources, and can extend overthe catchment below the mining site.The effects can also be long term.

Socio-economic effectsThe indirect effects of a mining projectrelate mostly to socio-economicchanges. Large mining projects willalways act as a magnet to people insearch of work. Water supplies for alluses are stretched further, and the intro-duction of disease and water contami-nation by sewage are likely to occur.These factors are, very often, the mostdifficult to assess, because predictingthe scale of immigration and its effectsIS never easy.

Assessment of the magnitude, extent,and duration of an impact is made byhaving a detailed understanding of theproject proposals and an understandingof the likely response of the environ-ment to the proposals. The significanceof an impact can then be assessed bymatching the magnitude, extent, andduration of an impact against the valueof a resource for people and wildlife,which is established during the evalua-tion of the baseline. It is particularly

WATERLINES VOL. 14 NO.1 JULY 1995 21

The way forward?In Ghana, new mining projects cer-tainly have adverse consequences forenvironmental resources. There is nodoubt, however, that the quality ofenvironmental protection and theawareness of environmental problemsis considerably better than in the darkdays before the introduction of envi-ronmental impact assessments. Theresult is markedly better environmentalconditions in the vicinity of the pro-jects, and these projects have appropri-ate plans which seek to minimizefuture environmental degradation.

The problem withmitigationThe implementation of mitigation mea-sures is not always straightforward,and can cause conflict between localgroups, traditional land-holding andadministrative structures, and the (new)national government authorities. Forexample, a mining company can striveto protect a forested area because of itswildlife interest and value for water-shed management. Whilst this may beagreed with the government authori-ties, the local chief may sell the log-ging rights, so that the forest is lostanyway. A clear understanding of thelocal political environment is needed,therefore, before implementing thistype of mitigation.

Further problems occur with com-pensation. Its value as a form of miti-gation depends on who receives it. Alltoo often, it is unclear who shouldreceive the compensation, and whetherthe most vulnerable members of acommunity benefit.

Mitigation must be implemented atan appropriate level of technology, andshould not encourage over-dependenceon the project. While a mining projectshould seek to minimize its impacts onlocal people or, in some cases, improveconditions - for example, by improv-ing access to water supplies - themine owners and managers should notbe expected to solve all local problems.The use of high-technology solutionswhich, unless operated by the minewould fall into disuse, can lead to over-dependence. The key is careful mitiga-tion planning, and the use of appropri-ate, probably simple, technology.

Dr Oliver Carr is Associate Director of SGSEnvironment, Yorkshire House. Chapel Street,Liverpool L3 9AG. UK. Fax:+44 1512581511.

ease vectors, such as pools which mayact as mosquito-breeding sites.

Control measures include the use ofsystems to treat wastes such as sewage,or the use of sedimentation ponds toreduce suspended solids loadings. Inthe case of gold-mining projects, effec-tive schemes to treat processing waters- and thus protect local waterresources - are needed and, in gen-eral, are incorporated into project pro-posals.

Compensation should be consideredas a last resort, albeit an essential one.Compensation can range from replace-ment, for example, of drinking-watersupplies lost to the project by newborehole or treated-water supplies. Itcan also involve financial remunerationfor lost resources such as lost fishingsites and catch returns.

'Restoration' is the attempt toreplace the resources lost following anadverse impact. An example would bethe restoration of land following a min-ing operation which, in the context ofwater resources, would restore catch-ment-drainage characteristics as wellas land productivity.

During the operational phase of amining project, monitoring plays animportant role, in ensuring that mitiga-tion measures are carried out thor-oughly, and that the project responds toproblems and complaints as they arise.This requires the formulation ofan environmental-management systemwhich empowers staff both to solveproblems, and to report at a highlevel in the company structure sothat environmental issues are broughtto the fore.

Hazards associated with mine water tailings lagoons must be clearly identified toprevent use by local people.

important to understand the signifi-cance of an impact because this deter-mines whether an impact or combina-tion of impacts can be consideredacceptable, or whether mitigation mea-sures or alternative proposals areneeded.

Managing environmentalimpactsThe main challenge of an environmen-tal assessment is to devise alternativeproposals, or to develop mitigationmeasures to prevent, control, repress,or compensate, and to ensure the pro-tection of people and wildlife resourcesas and when necessary. It is also impor-tant that mitigation measures, in partic-ular preventive measures, are consid-ered at an early stage in the project.This allows time for improvements atthe outset of the planning stage, beforethe proposals are fixed, and mitigationbecomes difficult to incorporate.

Mitigation must address the impactspresented in the EIA. It is crucial thatimpact assessors are experienced, toensure that the importance of impactsand the effort given to mitigation isappropriate. This also goes back to thebaseline study, in particular to justifyspending on mitigation, where thevalue of particular resources has beenevaluated.

The most effective forms of mitiga-tion prevent environmental damage.This can involve altering proposals toavoid sensitive areas such as fish-breeding sites, or to prevent the cre-ation of sites which can be used by dis-

22 WATERLINES VOL. 14 NO.1 JULY 1995