EIA

Question 1

Define ‘Life Cycle Assessment’ (LCA)

Answer 1

Life Cycle Assessment is an objective process to evaluate the environmental burdens associated with a product, process or activity, by identifying energy and materials used and wastes released to the environment, and to evaluate and implement opportunities to affect environmental improvements.

(SETAC, 1990)

Question 2

What are the key objectives of LCA?

Answer 2

• Identify and quantify the environmental loads involved - e.g. the energy and raw materials consumed, the emissions and wastes generated
  
  • System-wide examination (whole cycle)
  • Multi-media approach (air, water, solid waste)
• Evaluate the potential environmental impacts of those loads (e.g. the car tyre)
• Assess the options available for reducing these environmental impacts
  
  • Identify trade-offs among alternatives
  • Identify opportunities to improve systems
  • Done in high-impact areas first
• Support environmental decision making
  
  • (e.g. right now gas is almost as cheap as coal, so we should invest more in gas to maybe kill coal industry)

Question 3

What is meant by the term ‘product system’ in the context of LCA?

Answer 3

A product system is defined by ISO as a ‘collection of materially and energetically connected unit processes, which perform one or more defined functions.’

(ISO 14040, 2006)

Question 4

What is meant by the term ‘system boundary’ in the context of LCA?

Answer 4

A system boundary establishes a specific set of criteria designating which unit processes are part of the product system.

(ISO 14040, 2006)

Question 5

What is meant by the term ‘elementary flows’ (which includes both inputs and outputs) in the context of LCA?

Answer 5

Elementary flow is split into both inputs and outputs: inputs are the raw material or energy taken from the environment entering the product system; and outputs are the material or energy leaving the system that are released into the environment.

(ISO 14040, 2006)

Question 6

Why is it important to consider the inter-linkages between resources and their life cycles?

Answer 6

The energy security, water security and food security sectors are harmoniously linked with one another, in that actions that take place in one sector will most likely directly impact upon one or the two other sectors also.

Question 7

What is meant by the analysis of the Energy, Water and Food (EWF) Nexus and how it is implemented?

Answer 7

Analysis of the EWF Nexus includes the identification, integration and evaluation of linkages related to the inputs, outputs and environmental impacts of a product process operating within governed system boundaries across the energy, water and food sub-systems throughout their life cycle

Question 8

Draw a schematic representing the EWF nexus in the context of LCA.

Answer 8

Question 9

What are the LCA phases?

Answer 9

1. Goal and scope definition (5-10%)
2. Inventory analysis (70%)
3. Impact assessment (10%)
4. Interpretation (10%)
   
   • Development and improvement
   • Strategic planning
   • etc.

Question 10

What is involved in ‘Goal Definition’, in the Goal and Scope Definition LCA phase?

Answer 10

Goal definition:

• identify the decision context (e.g. CO2 emmissions from coal fired power plant),
• intended application (product development and improvement, strategic planning, public decision making, marketing, other, (e.g. reduce CO2 emmissions by x% by 20XX)
• identify the audience. (present information appropriately to the public etc.)

Question 11

What is involved in ‘Scope Definition’, in the Goal and Scope Definition LCA phase?

Answer 11

• Describe the system to be studied, the functions of the system, the functional basis for comparison and the required level of detail.
  
  • Comparison on the basis of an equivalent function (1000 liters of milk packed in glass, plastic bottles or packed in carton, instead of 1 glass bottle versus 1 carton)
• Define:
  
  • the life stages to be covered,
  • the impacts to be investigated,
  • the impact assessment methods to be applied,
  • the interpretation methods to be used,
  • the assumptions made about data and method issues,
  • value choices, limitations, data quality requirements,
  • type of critical review and
  • format of the report required.

Question 12

In LCA, what is a cutoff?

Answer 12

An impact not under consideration because it’s effect is very small (e.g. <1.5% of overall)

Question 13

What is the Inventory Analysis LCA phase?

Answer 13

Inventory Analysis is the LCA phase involving the compilation and quantification of inputs (e.g. raw materials and energy) and outputs (e.g. wastes and emissions) for a given product system throughout its life cycle.

Steps:
– preparing for data collection
– data compilation
– calculation procedures
– allocation and recycling

Question 14

What happens in the Impact Assessment phase of an LCA?

Answer 14

• Life Cycle Impact Assessment is the 3rd phase of LCA
• The effects of the resource use and emissions generated are grouped and quantified into a limited number of selected and defined baseline impact categories which may then be weighted for importance
• Additional selection and definition of indicators and models
• Classification
• Characterisation (model convert to equivalent terms)
• Normlisation to e.g. EU standards i.e. make additive e.g. GWP (kg/CO₂ eq.) (EU standards different to African standards, for e.g. eco toxisity valued less in African)
• Aggregation and/or weighing
  
  • In the evaluation phase the normalized effect scores are multiplied by a weighing factor representing the relative importance of the effect.

Question 15

What happens in the Interpretation phase of an LCA?

Answer 15

• Results interpreted and reported in the most informative way possible.
• The need and opportunities to reduce the impact of the product(s) or service(s) on the environment are systematically evaluated based on the data.
• Includes quality, completeness, sensitivity and consistency analysis/checks
• Address the uncertainty and accuracy of the results.
• Conclusions are drawn
• Highlight limitations
• Recommendations are derived.
• All relate to the goal and scope of the research
• Should include a review by independent experts

Question 16

What is a functional unit?

Answer 16

A functional unit is a quantified description of the performance of the product systems, which is used as a reference unit

Question 17

What does gate-to-gate, cradle-to-gate, and cradle-to-grave mean in the context of LCA?

Answer 17

They are each a type of LCA

• Gate-to-gate: Considers production of good only (e.g. takes place just at plant)
• Cradle-to-gate: Raw materials to finished good (no use or end life considerations)
  
  • e.g. build coal power station close to coal source to save on transport
• Cradle-to-grave: Considers everything from harvesting materials to the disposal of the finished goods and wastes (landfill or recycled), and the life-time of the infrastructure (demolition?)

Question 18

What are the system boundaries, typically?

Answer 18

• Natural resource aquisition
• Materials production
• Intermediate products manufacturing
• Assembly manufacturing
• Use
• End-of-life

Question 19

What is a reference flow?

Answer 19

A quantified amount of product(s), including product parts, necessary for a specific product system to deliver the performance described by the functional unit

Question 20

In LCA, what are some environmental interventions and economic flows?

Answer 20

Question 21

In Life Cycle Inventory Analysis (phase 2), what calculation procedures need to be done?

Answer 21

• relate process data to the functional unit (matrix algebra)
• allocation of multiple processes (multiple outputs, multiple inputs, re-use and recycling)
  
  • e.g. coal power plant
  • fly ash: utilized in road construction, and used to stabalize heavy soil; contains heavy metals
  • once coal power plant closes down need to find new ways to produce gypsum
  • Particulate matter potent
• aggregation over all unit processes in the inventory table

Question 22

List the possible baseline impact categories present in a LCIA.

Answer 22

• Depletion of abiotic resources
  
  • e.g. fuel consumption, coal, copper, natural gas
• Impact of land use
• Climate change
• Human toxicity
• Ecotoxicity (diff. animals in diff. env - diff. comparison)
  
  • freshwater aquatic ecotoxicity
  • marine aquatic ecotoxicity
  • terrestrial ecotoxicity
• Photo-oxidant formation
  
  • photooxidation from NO_x from exhaust fumes
• Acidification
  
  • SO_x, NO_x
• Eutrophication
  
  • fertilizers e.g. nitrates, phosphates

​Results still difficult to understand due to differences in scale and units e.g. local toxicity vs global climate change

Question 23

During LCIM, normalization does what?

Answer 23

Normalisation relates the results to a reference value, for example, total world impacts in 2002. Result is often referred to as the normalised environmental profile.

But even after normalisation, there is no clear answer:

• aggregation of (normalised) impact category results into a single index
• subjective weighting factors increase the priority given to impactcategories we think are important, and decrease the priority given to those we think are unimportant

In order to gain a better understanding of the relative size of an effect, a normalization step is required. Each effect calculated for the life cycle of a product is benchmarked against the known total effect for this class.

• Normalization enables you to see the relative contribution from the material production to each already existing effect.
• Normalization considerably improves our insight into the results. However, no final judgement can be made as not all effects are considered to be of equal importance.

Question 24

How do impact categories relate to damage categories?

Answer 24

Question 25

If all the scores for one product are higher than those for another, it is easy enough to conclude which is the more environmentally friendly. But if one has a higher score for acidification, while the other has a higher score for the greenhouse effect it becomes difficult to justify such a conclusion.

Interpretation depends on what two factors:

Answer 25

• The relative size of the effect compared to the size of the other effects. It is important to see whether a seemingly arbitrary score of say 100% refers to a very high or an extremely low effect level. This is normalisation.
• The relative importance attached to the various environmental effects. This is evaluation.

Question 26

Environmental impact monitoring aims at determining what?

Answer 26

Determining the occurence and magnitude of an impact. It is also important to establish that the perceived change is a consequence of the project under consideration and not the function of some other cause.

The changes might result, for example, from natural variations in the parameter monitored or may be the result of some other development in the vicinity and, thus, not related to the projet under consideration.

Question 27

What are ‘reference monitoring locations’?

Answer 27

During environmental impact monitoring, it is common practice to use reference monitoring locations in order to ensure that an impact is assigned correctly to a project. The reference locations are selected in areas similar to the treatment (impact monitoring) locations where the impacts are not expected to occur.

For example, a number of river quality monitoring stations may be put downstream of an industrial effluent discharge point, together with reference stations upstream and downstream of the same river and its tributaries.

Question 28

There are several techniques of gathering and monitoring environmental data. The basic techniques
include:

Answer 28

o Grab sampling techniques with periodic data analysis
o Automated sampling techniques with periodic data analysis
o Automated continuous monitoring and data analysis
o Biological monitoring systems

Question 29

What are the disadvantages of using traditional monitoring techniques?

What is the advantage of using continuous monitoring techniques over these traditional monitoring techniques?

Answer 29

• Traditional monitoring techniques involving periodic sampling are often used in industry to monitor environmental variables.
• These methods have the disadvantage that by the time these samples are analysed the impact of the pollutant on the environment can have already occurred.
• Furthermore, with this type of sampling all but the most rudimentary (i.e. undeveloped/basic) process control techniques are impossible to use.
• Recent improvements in the continuous monitoring technology can allow certain environmental
  attributes to be monitored continuously in real time, thus allowing a control system to be established

Question 30

Planning permissions for the operation of mining licenses often require, environmental monitoring and sampling of particular environmental variables at what frequencies

Answer 30

frequencies far beyond those which could be achieved by none automated methods.

However, most environmental data collection techniques are, for the most part, not automated.

The manual or semi computerised analysis of large volumes of data of the different environmental variables in different systems does not facilitate the accurate collation of the data or allow for the introduction of an automated control system.

Question 31

What are grab sampling techniques usually used for?

Answer 31

Simple data gathering techniques such as grab sampling are often used for the evaluation of water quality, soil quality and gaseous emissions. These methods have the disadvantage that by the time these samples are analysed the impact of the pollutant on the environment could have already occurred. This has a particular importance in sensitive areas such as effluent discharge into rivers or ground water control in and around tailings dams.

Question 32

Briefly describe what continuous monitoring means.

Answer 32

The more sophisticated approach is that of continuous monitoring of the environment. A precise definition of continuous monitoring is rather difficult due to a number of different implementations.

Generally the term ‘Continuous’ is applied to all monitoring instrumentation that has the ability to repeatedly monitor one or more attributes at a regular interval.

The frequency of the measurement may be defined by the user, or by the physical limits of the monitor.

Question 33

Some types of environmental data are not suitable to be continuously monitored, nor would the continuous monitoring of these parameters be useful. Give examples.

Answer 33

An example of this would be a study of soil contamination, in which samples would be taken at regular intervals in time to study the cumulative effects.

Other examples would include biological surveys which would be virtually impossible to automate and the day to day results would not yield useful information.

Question 34

Give exclusive examples of typical continuously monitored environmental variables

Answer 34

• River water quality
  
  • Flow rate
• Water quality at ground water wells
  
  • Chemical content
• Noise
  
  • L_eq, L_max, L_n, L₁₀
• _​Air quality
  
  • Ambient dust,
  • gaseous emissions
• ​Meteorology
  
  • Wind direction,
  • wind v,
  • rainfall,
  • T,
  • humidity
  • sunshine hours

Question 35

Give examples of typical periodically monitored environmental variables

Answer 35

• Soil quality
  
  • metals
  • nitrates, sulphides
  • Org content
  • pH
• Soil herbage
  
  • bio-diversity, bio-population
  • metal cont.
• Water quality
  
  • BOD, COD
• Biological surveys
  
  • bio-diversity, bio-population
  • metals
  • general condition
• Air quality
  
  • Dust deposition
  • composition

Question 36

What are the potential impacts associated with mining?

Answer 36

• Acid Mine Drainage Formation (open cast)
• Erosion and Sedimentation
• Chemical Releases – Cyanide (used at Tara) & other
• Air emissions/air quality
  
  • Stacks for drying product in place for ~25 years before being put out of use (Tara)
  • Fugitive dust emissions (e.g. off road or tailings pond)
  • Ventilation raises that pump not-so-fresh air out of mine to surface
• Habitat modification
• Surface water pollution
• Groundwater pollution
• Noise
  
  • Complaints
• Ground vibration
  
  • Blast vibration twice a day
  • Development blasting in morning / production blasting in evening
  • Biggest source of complaint
• Tailings pond failure (disaster)
  
  • slurry-soild water mixture flows into nearby valleys

Question 37

What is the main disadvantage of using non-automated environmental collection techniques?

Answer 37

The manual or semi-computerised
analysis of large volumes of data of the different environmental variables in different systems does not facilitate the accurate collation of the data or allow for the introduction of an automated control system.

Planning permissions for the operation of mining licenses often require, environmental monitoring and sampling of particular environmental variables at frequencies far beyond those which could be achieved by none automated methods.

Question 38

What are the advantages of using continuous monitoring systems?

Answer 38

• Continuous Data in Time
• Instantaneous data
• Remedial action/closed circuit control possible
• Sampling error is minimised
• Less labour required
• A large amount of data

Question 39

What are the disadvantages of using continuous monitoring systems?

Answer 39

• Complex to install, maintain and operate
• Difficult to tailor a suitable ‘Customised’ system
• Calibration has to be carried out at regular intervals
• System is only as accurate as instrument
• Skilled labour required
• A large amount of data to process
• Initial capital cost
• Not suitable for all environmental attributes

Question 40

Give an example of a particular type of environmental data that is not suitable to be continuously monitored and why.

Answer 40

The study of soil contamination, or bio-diveristy in animal health studies, in which samples would be taken at regular intervals in time to study the cumulative effects.

The continuous monitoring of these parameters are not useful as the day to day results would not yield useful information.

Question 41

What are the potential sources of air pollution at the Tara Mine site?

Answer 41

• There are 4 air extraction stacks associated with the minerals processing plant (or Mill):
• These stacks are the crusher, the lead loadout, the zinc loadout and the zinc dryer
• Ventillation raises
• Dry tailings
• Roads

Question 42

The air quality impacts from minerals extraction (primary extraction of minerals + on-site processing) sources occur at what scale?

Answer 42

The air quality impacts from these sourcs occur at what is defined as a local scale in air quality modelling, primarily distances up to 10km.

Air pollutants at this scale are contained within what is termed the boundary layer of the atmosphere.

Question 43

What are the five factors that define the air pollution caused by minerals extraction?

Answer 43

• The spatial extent of the source. This can be of 3 types over 3 dimensions: point, line and area.
• The temporal extent or duration of the source. A source of air pollution may be instantaneous or occur over a period of time, or intermittently over a period of time.
• The type of air pollutant released. Primarily particulates, mainly in the form of dust.
• The effect of air pollution on the recipient.
• Minerals extraction is also likely to occur in or result in complex or highly varying surface topography. This can have a considerable influence on the dispersion of an air pollutant.

Question 44

What are some of the typical sources of air pollution from minerals extraction activities (including processing of minerals)

Answer 44

• Point
  
  • Ventillation outlets
  • Processing plants
  • Drilling
• Line
  
  • Truck haulage routes (can be treated as point sources over small temporal scale)
• Area
  
  • Tailings dams
  • Spoil heaps
  • Storage areas

Question 45

Blasting operations are temporally classified as what?

Answer 45

• Classified depending on the time scale of interest
• On a small time scale, say daily, blasting operations will be instantaneous sources of pollution.
• On larger time scales, say over a year, they could be considered as continuous sources of air pollution.

Question 46

What is the Planetary Boundary Layer?

Answer 46

The part of the atmosphere directly influenced by the Earth’s surface.

Question 47

The process of entrainment does what to pollutants?

Answer 47

Traps pollutants within the boundary layer.

Question 48

Objective measurements of sound levels are an indispensable part of any environmental noise
protection program. Environmental noise levels vary greatly – noise is often impulsive or contains
pure tones.

Assessing a fluctuating noise level means getting what?

Answer 48

a value for a level that is, in simple terms, the
average level.

The “equivalent continuous sound level”, the L_eq is known across the globe as the essential averaged parameter.

Question 49

What is L_eq, and how is it measured?

Answer 49

L_eq is a measure of the averaged energy in a varying sound level.

It is not a direct measure of annoyance. Extensive research, however, has shown the L_eq to correlate well with annoyance. It is obvious, though, that a noise level acceptable on a Wednesday afternoon may be distressing early on Sunday. Corrections for time of day may, therefore, be applied.

The Leq is measured directly with an integrating sound level meter (SLM)

Question 50

An analysis of the statistical distributions of sound levels is a useful tool when assessing noise.

Why?

Answer 50

The analysis not only provides useful information about the variability of noise levels, but is also prominent in many standards as the basis for assessing background noise.

For example, L₉₀, the level exceeded for 90% of the measurement time, is used as an indicator of background noise levels while L₁₀ or L₅ are sometimes used to indicate the level of noise events.

Question 51

What are the different kinds of SLMs?

Answer 51

• A number of different types of noise measurement equipment are commercially available with various levels of sophistication.
• The range includes instruments that are capable of:
  
  • measuring basic time varying sound pressure level
  • calculating statistical noise indices over time.

Question 52

Integrating or integrating averaging sound level meters will measure what?

Answer 52

the ‘A’-weighted equivalent sound level, L_Aeq.

Question 53

Statistical sound level meters will calculate what?

Answer 53

the statistical noise measurement parameters such as L_A90, L_A10, L_Amin, L_Amax as well as the L_Aeq.

Question 54

Environmental noise measurement using sound level meters, microphones and calibrators by both the Operator and the Regulator of have to comply with what?

Answer 54

a range of national and international standards

e.g. ISO standard in UK

Question 55

What’s the difference between basic and more advanced SLM instruments?

Answer 55

• Basic instruments may need to be manually interrogated and the results read off and recorded manually.
• More sophisticated models may be equipped with a noise logging facility. This will allow the meter to be set up to take one sample over a pre-defined period, store the result in its memory, start another measurement, and repeat the process continuously.
• All meters are able to able to measure in terms of dB(A) noise levels, this being the most commonly used scale for environmental noise assessment.

Question 56

Modern sound level meters usually have a wide dynamic range of around 80dB and can measure peak levels of over 140dB. And the measurement scales go down as low as 20dB(A).

What does this range allow for?
And what is the disadvantage of measuring as low as 20dB?

Answer 56

The range means that they can measure background (LA90) levels of say, 30 dB and still capture L_Amax, levels of over 100 dB.

Some meters at low levels produce electrical noise and when combined with thermal noise from some microphones, can start to influence the results, so in practice any level measured below 25dB(A) should be viewed with caution.

Question 57

What is it common to prescribe to the Equivalent continuous sound level, L_eq?

Answer 57

• Because the Leq is defined as the steady sound level that contains the same amount of acoustic energy as the fluctuating level over the prescribed time.
• It is common to prescribe periods of:
  
  • 1 hour (L_1h),
  • 24 hour (L_24h),
  • the day time hours from 7:00 a.m. to 7:00 p.m. (L_day), and
  • the night time hours from 11:00 p.m. to 7:00 a.m. (L_night).

Question 58

What is Day average sound level, L_day?

Answer 58

The equivalent continuous sound level in decibel determined over all the day periods of a year (the 12 hour time period from 07:00 to 19:00) is called day average sound level

Question 59

What is Evening average sound level, L_evening?

Answer 59

The equivalent continuous sound level in decibel determined over all the evening periods of a year (the 4 hour time period from 19:00 to 23:00) is called evening average sound level.

Question 60

What is Night average sound level, L_night?

Answer 60

The equivalent continuous sound level in decibel determined over all the night periods of a year (the 8 hour time period from 23:00 to 07:00) is called night average sound level.

Question 61

What is Day-evening-night average sound level, L_den and how is it calculated?

Answer 61

L_den is a long-term noise annoyance indicator recommended for use in strategic noise mapping by the Environmental Noise Directive 2002/49/EC.

L_evening and L_night have a 5 and 10 dB weighting applied to each respectively to take account of the difference in annoyance due to the time of day.

Question 62

What is Day-night average sound level, L_dn?

Answer 62

This is an average sound level taken over a 24-hour period, modified to account for the increased undesirable effect of noise at night.

10 dB is added to the actual sound level for the hours from 23:00 to 07:00. before the 24-hour energy average is taken.

Question 63

What is Maximum A-weighted sound level, L_Amax?

Answer 63

The highest sound level measured on a sound level meter, during a designated time interval or event, using fast time-averaging and A-weighting is defined as maximum A-weighted sound level.

Question 64

Why are noise levels rarely constant?

What are the exceptions to this?

Answer 64

• because the overall sound pressure is usually the result of numerous different sources of noise, each of which may be varying in strength from one instant to the next.
• Exceptions tend to be when one particularly constant source is very loud compared to the rest (e.g. close to an extract fan in a factory wall) or when all noise sources are at large distances from the receiver (e.g. in the bedroom of a remote house at night).
• Therefore it is usual to quantify a noise level over a specified period of time.

Question 65

Describe what “Percentile Parameters” used in characterising environmental noise are.

Answer 65

• The L_n value is the noise level exceeded for n% of the measurement period, which must be stated.
• The L_n value can be any value above 0 and up to 100.
• The time period of the measurement should be specified and it should be long enough to obtain a representative sample of the background level.
• E.g. L_A90, L_A10, L_A50
• L_A90 is the lowest statistical reading, and that the L_A10 is higher and the L_A50 lies between them.

Question 66

Describe L_A90.

Answer 66

• The most commonly used percentile level is the L_A90 which is the 90th percentile level and is level exceeded for 90% of the measurement time.
• It will be above the Lmin and has been adopted as a good indicator of the “background” noise level.
• Whilst it is not the absolute lowest level measured in any of the short samples, it gives a clear indication of the underlying noise level, or the level that is almost always there in between intermittent noisy events.

Question 67

Describe L_A10.

Answer 67

• L_A10 is the tenth percentile, or the level exceeded for 10% of the time, and was often used for road traffic noise assessments since it had been shown to give a good indication of people’s subjective response to road traffic noise.
• Although the L_Aeq has been largely superseded its use for road traffic, it may still be found in acoustic reports discussing road traffic noise and is used to assess road traffic noise where a noisy road is being planned.
• The L_A10 can be useful in assessing the overall noise climate, for example if the L_A90 L_A10 L_Aeq are all within a few dB then this can be taken as an indication that the noise source is fairly constant.

Question 68

What is the objective of Environmental Impact Assessment (EIA)?

Answer 68

• The objective of EIA is not to force decision makers to adopt the least environmentally damaging alternative. If this were the case, few developments would take place.
• Environmental impact is but one of the issues addressed by decision makers as they seek to balance the often competing demands of development and environmental protection.
• Social and economic factors may be far more pressing.
• As decision makers may be dealing with a disparate range of information on which to base a decision, integration has been a recurrent problem.
• Economic and environmental analyses, for example, tend to be treated seperately. In fact, they are closely interrelated.

Question 69

Define ‘environmental impact’

Answer 69

A projected change in the value of one or more measures of environmental quality resulting from an action, compared with the condition of the environment had that action not taken place.

An impact can have both spatial and temporal effects and is hence, four dimensional.

An impact can also be direct (primary) or indirect (secondary, tertiary, etc.).

Question 70

What are the stages of EIA?

Answer 70

• Impact identification
• Forecasting of impacts
• Evaluation of impacts
• Communication of results

Question 71

List the main criteria used in choosing a suitable environmental impact assessment method for a development project.

Answer 71

1. Is the method comprehensive?
2. Is the method selective?
3. Is the method mutually exclusive?
4. Does the method yield estimates of the confidence limits to be assigned to the predictions?
5. Is the method objective?
6. Does the method predict interactions?

Question 72

‘Is the method comprehensive?’ is one of the main criteria used in choosing a suitable environmental impact assessment method for a development project.

Describe what that means.

Answer 72

Sometimes a method should be able to detect all of the important impacts and combination of impacts, not only the expected, but possibly new or unsuspected impacts.

Question 73

‘Is the method selective?’ is one of the main criteria used in choosing a suitable environmental impact assessment method for a development project.

Describe what that means.

Answer 73

Sometimes a method should focus attention on major impacts, eliminating at an early stage unimportant impacts that could dissipate effort in the final analysis.

Care has to be taken not to introduce bias when pre-determining the importance of an impact.

Question 74

‘Is the method mutually exclusive?’ is one of the main criteria used in choosing a suitable environmental impact assessment method for a development project.

Describe what that means.

Answer 74

The sometimes complex interactions that exist in the environment may lead to the inclusion of an impact in a study more than once unless care is taken.

Some impacts, however, can be viewed from differing perspectives, provided each impact is viewed uniquely.

Question 75

‘Does the method yield estimates of the confidence limits to be assigned to the predictions?’ is one of the main criteria used in choosing a suitable environmental impact assessment method for a development project.

Describe what that means.

Answer 75

This helps establish the validity of a method in assessing a particular impact, allowing analysis of results, and if necessary, alteration of predictions.

An indication is also given as to whether further study is required as a result of the prediction of a range of results.

Question 76

‘Is the method objective?’ is one of the main criteria used in choosing a suitable environmental impact assessment method for a development project.

Describe what that means.

Answer 76

Ideally a prediction method should contain no bias, primarily for two reasons.

The first is to ensure pre-conceptions of an assessor do not lead to desired predictions.

Second, to allow direct comparison of EIA for similar types of action.

Question 77

‘Does the method predict interactions?’ is one of the main criteria used in choosing a suitable environmental impact assessment method for a development project.

Describe what that means.

Answer 77

Methods of predicting impacts should be able to identify interactions and provide a means to estimate their effects.

Environmental systems contain feedback mechanisms. That is, a change in one environmental impact may cause unsuspected changes in another part of the environmental system.

Question 78

Describe, by giving examples, the matrix method used for environmental impact assessment

Answer 78

• The matrix method relates a set of environmental impact indicators to a set of human or development actions.
• The classic matrix method is the Leopold matrix (1971), which is one of the earliest EIA methods developed.
• The Leopold matrix lists X environmental ‘characteristics’ and ‘conditions’ along the vertical axis and X project actions along the horizontal axis, in an open-cell matrix.
• Two numbers are placed on a scale of 1 to 10.
• The scale reflects the possible magnitude (top left) and indicates the importance (bottom right) of an impact; 10 represents the greatest magnitude and importance, 1 the least.
• Not necessarily all of the cells will be used, dependent on a particular project.

Question 79

What are the advantages of using matrix methods in EIA?

Answer 79

• Matrix methods are useful in that they recognize that impacts result from the interaction of human actions with the environment.
• They are useful for identifying impacts and presentation of results

Question 80

What are the disadvantages of using matrix methods in EIA?

Answer 80

• Their validity in forecasting and interpretation of impacts is questioned:
• For example, in the Leopold matrix:
  
  • In the case of forecasting there is no guidance on the scaling system, so affecting objectivity;
  • No account is taken of the probability of an impact occurring as no variability is provided in the scaling system;
  • Interactions in the environment are not readily identified.
• In interpretation, the volume of information becomes a problem, with a possible 17600 scaled values for impacts. This arises as there is no provision to combine values to give a composite index.

Question 81

Describe, by giving examples, the ‘check-lists’ method used for environmental impact assessment

Answer 81

• These range from the simplest containing a comprehensive list of the environmental factors to be considered in an EIA through to those which provide guidance on the data required and associated techniques for prediction.
• Developments have also been made of quasi-mathematical check-lists using scaling and weighting.
• Check-lists in their simplest form as a listing of possible impacts are very useful in identifying impacts, provided the list is not regarded as all-embracing.
• Check-lists however, have several drawbacks, especially those using scaling-weighting.

Question 82

Give examples of the ‘check-list’ method of EIA

Answer 82

the Environmental Evaluation System (EES)

the Water Resources Assessment Methodology (WRAM)

Question 83

Check-lists used in EIA have several drawbacks, what are they?

Answer 83

• Each impact is looked at in isolation, thus ignoring the interactions and feedback loops that occur in environmental systems.
• Scaling-weighting also presents difficulties in assessing the weighting to be attached to an impact and can led to the temptation to quantify what is regarded as the unquantifiable to achieve completeness.
• Check-lists may also present a mass of potential impacts, not necessarily all of which are relevant, so obscuring the issue.

Question 84

Describe, by giving examples, the ‘map overlay’ method used for environmental impact assessment.

Answer 84

• The use of map overlays for impact assessment are ideally suited to the assessment of the spatial aspects of impacts.
• Transparencies are produced which show the spatial distribution and intensity of impacts in a geographic reference frame.
• These can be combined to produce a composite map showing total impact.
• The maximum practical number of transparencies that could be combined is about 10.
• Developments in computer techniques, such as digital cartographic mapping and especially geographic information systems, have greatly improved the potential of this method.
• Modern map manipulation methods (i.e. GIS) are a very effective method in the communication of the results of EIA.

Question 85

What are the advantages of the ‘map overlay’ method of EIA?

Answer 85

• Data can easily be manipulated to provide practical real-time sensitivity analysis.
• Map overlay is especially useful in site selection, whereby using computer-aided design software, locations can be chosen which provide minimum environmental impact.

Question 86

What are the disadvantages of the ‘map overlay’ method of EIA?

Answer 86

• Extreme impacts with small probabilities of occurrence may be overlooked, especially in localised areas.
• Sensitivity analysis and probability are not displayed effectively on individual composite maps (although the speed of modern computer based techniques in showing results of data manipulation overcomes this in part).
• Map overlay is subject to potential technical errors

Question 87

What are the disadvantages of the ‘map overlay’ method of EIA?

Answer 87

• Extreme impacts with small probabilities of occurrence may be overlooked, especially in localised areas.
• Sensitivity analysis and probability are not displayed effectively on individual composite maps (although the speed of modern computer based techniques in showing results of data manipulation overcomes this in part).
• Map overlay is subject to potential technical errors

Question 88

Describe the ‘simulation modelling’ method used for environmental impact assessment.

Answer 88

• Simulation modelling, or Adaptive Environmental Assessment and Management (AEAM) better achieves objectives, by integrating economic, ecological and environmental understanding from the start of the design process.
• AEAM involves two major activities:

1. The coordination of resources and the relevant parties, such as scientists, economists and decision-makers, in a process that integrates their talents and concerns in order to achieve a consensus on the important features and relationships in the environmental system being studied.
2. The use of computer-based simulation modelling to synthesise the environmental system, and allow the for the assumptions underlying the model to be altered to show the likely impacts resulting from the introduction of new external factors.
   The process of the construction of the model also provides guidance on the data requirements and research necessary to provide the data.

• This approach has been most widely used for natural resource management programmes and for proposals to exploit natural resources.

Question 89

What are the advantages of AEAM (simulation modelling) in EIA?

Answer 89

• It takes into account the interrelations present in environmental systems, and
• Allows investigation of changes in parameters of a system.

Question 90

What are the disadvantages of AEAM (or simulation modelling) in EIA?

Answer 90

• Whilst the use of a team of experts in defining the simulation model helps focus attention on key impacts and issues, the composition of these groups is limited, and to what extent additional involvement from the outside should take place is in debate.
• Simulation modelling is also subject to the common problem of all EIA methods, the tendency to quantify the unquantifiable, based on uncertain data.

Question 91

How did the simulation modelling method for EIA come about?

Answer 91

• AEAM arose out of a dissatisfaction with the ‘reactive’ approach taken in previously commonly used methods of EIA.
• The process of decision making (within projects and policy) previosuly centred on achieving economic goals with the environmental impacts being reviewed secondarily.
• This gives rise to two major difficulties:

1. The basic properties of a project or policy are set early in the design stage, allowing little scope for major redesigns.
2. The present reactive and protective attitude towards the environment makes environmental assessment arbitrary, inflexible, rather than as an integral part of project design.

• T.f. The tendency to incorporate all data into EIA, focussing on the present state of the environment, removes proper anticipation and direction towards future alternatives.
• AEAM better achieves objectives by integrating economic, ecological and environmental understanding from the start of the design process.

Question 92

What EIA method is most appropriate for the needs of the minerals industry?

Answer 92

An EIA method which will combine the benefits of map overlay and simulation modelling (including sensitivity and interaction analysis) techniques

Question 93

What is a baseline study?

Answer 93

• Baseline studies are required to establish initial environmental conditions and refers to the collection of background information of the environmental and socioeconomic setting for a proposed development project and it is normally one of the first activities undertaken in an EIA.
• A comparison must be made between the “with project” and “without project” situations.
• The “without project” situation refers to likely environmental conditions taking place over time in the absence of the proposed development, not just the set of environmental conditions prevailing prior to commencement of the project.
• A baseline study describes the relevant aspects of the physical, biological and social environments which could be affected by the considered development project by accumulating any information which is available on the general topics of land, water, air and people.
• Baseline studies should provide a framework for making predictions of environmental conditions over time, regardless of whether the development proposal is actually implemented.

Question 94

Describe the relationship between baseline studies and environmental monitoring in an Environmental Impact Assessment programme.

Answer 94

• A baseline study is ‘a description of conditions existing at a point in time against which subsequent changes can be detected through monitoring’.
• Therefore, baseline studies are closely associated with environmental monitoring which would help in assessing the change, over space and time, in the environment as a result of a development project.
• The relationship between baseline studies and monitoring is shown in the image.
• Baseline studies would be used to establish statistically valid descriptions of selected environmental attributes prior to the onset of the project under consideration.
• Simulation modelling would be used to predict the extent to which these values would change as a result of the project.
• When the project becomes operational, the baseline variables would be re-measured, over time, to determine the extent to which the predicted changes had occurred.

Question 95

What factors have to be appraised in the design of an environmental monitoring system?

Answer 95

Primarily, the environmental variables that will be monitored, and secondly the frequency at which these variables must/can be evaluated.

Environmental legislation and the terms and conditions of any planning consent would provide the guidelines for these decisions.

Question 96

What is the ‘Environmental Unit’?

Answer 96

The “Environmental Unit” in a mine which monitors the impacts of mining operations is a multi skilled group of people whose qualifications vary from biochemistry to instrumentation to land reclamation techniques.

This means that environmental units should consist of people with a wide range of skills and abilities:

• geochemistry
• biochemisty
• numerical modelling
• measurement/instrumentation and analysis
• information technology
• ecology
• reclamation techniques.

Question 97

What is the role of the Environmental unit?

Answer 97

• Generally the main duties of the unit are to actively monitor those parameters required by law.
• Mine operators may also adopt, voluntarily, recommended guidelines agreed by their professional associations, and obviously the responsibility of monitoring these parameters also fall within the realm of the environmental unit.
• Normally environmental units have no direct control over the mining operations, however it must be emphasised that a mine may only be operational if it remains within the limits specified by the planning permission.

Question 98

There are many advantages to a continuous monitoring system. There are also many disadvantages some of which have been described. The success or failure of an automated system depends on a large number of local factors. Give an example of this.

Answer 98

The installation of water logging instrumentation in water which is highly mineralised would lead to poor and inaccurate results as the minerals deposit on the sensor.

Hence the sensor would have to be cleaned and calibrated at regular intervals which might render the installation of such an instrument cost ineffective.

Question 99

What is the largest problem with continuous instrumentation?

Answer 99

Calibration:

Calibration on some instruments can be automated, however many require regular calibration and cleaning. Thus continuous monitors may provide plenty of useless none calibrated data which is worse than no data at all.

Question 100

Describe the principles of biological monitoring used in environmental management and give examples from mining practice.

Answer 100

• Biological monitoring systems can be considered as a type of continuous monitoring system.
• The technique employs natural animal species living in the potentially affected areas as a monitoring system.
• Such a system can be described as continuous as the organisms are constantly exposed to the effects of the environment around them.
• This type of technique has the advantage that it can often be used to observe the actual direct impact of changing conditions upon the environment.
• The use of organisms to indicate and interpret environmental conditions or biological monitoring has an important part to play in the environmental management of mining systems.
• Biological monitoring technique are complimentary to physical, chemical or electronic monitoring as they show the reaction of organisms to the pollutants indicating the level of impact. On the other hand, chemical or electronic monitoring techniques measure and indicate the levels of pollutants in the environment.
• Examples would include the monitoring of stream pH, salinity, sediment or toxic metal content using either sensitive or tolerant organisms; dust monitoring using moss bags; or the detection of mutagens using cell biology techniques.

Question 101

List the characteristics of biological monitoring systems?

Answer 101

• Omni present or may be readily installed,
• Low cost, therefore a large number of sensors are possible,
• Toxicity is measured rather than potential toxicity,
• Interactions and synergism’s are recorded,
• Long term effects and trends may be integrated,
• Short term events and catastrophes are recorded,
• Unanticipated factors may be recorded,
• Trace substance concentration may be biomagnified.

Question 102

Give an example of a mine that has adopted the approach of biological monitoring?

Answer 102

• Somincor, a copper tin mine in Southern Portugal has adopted this approach for the monitoring of atmospheric pollution (metal deposition) around the mine area.
• This provides the mine with a low cost monitoring system for fugitive dust emissions derived from mining activity at a large number of sites.
• The bio-monitoring scheme is based upon epiphytic lichens collected from SW Portugal.

Question 103

Referring to your field work at Tara Mines, give an example of the equipment and methodology used in monitoring air quality.

Answer 103

• Tara Mines have three stations used for monitoring meteorological conditions.
• One is used as the main meteorological monitoring station with equipment for measuring wind speed and direction, air T, and both dry-bulb and wet-bulb T (and hence humidity).
• Measurements are averaged over 1 hour.
• In addition, measurements of the cloud cover are made on a daily basis.
• Using the meteorological measurements and information on the sources of the pollution, two studies have been carried out at the mine:
  
  1. Average air concentrations of zinc predicted at ground level which was overlaid by land use.
  2. At both the maximum permitted and average emission rates of total solids, monthly averages of dust deposition are calculated for all the sources combined.
• A GIS analysis is then carried out that combines the results from the air quality model and a grid of all the buildings in the surrounding geography, to produce a grid showing a simple evaluation of a possible risk due to air pollution.

Question 104

Describe sound power level used in environmental noise assessment and explain how it is calculated.

Answer 104

• Sound power level is the energy output of a source and it is a property of the source itself.
• The sound power level is a ratio of the power of a source and a reference level and is quoted in dB.
• The sound power level is defined as:

Eqn in image

Where, W is the sound power of the source (watts); and W₀ is the reference sound power (10^-12 watts)

• The sound power level is usually calculated from a series of measurements made around the equipment under carefully defined conditions.
• There measurements usually are sound pressure levels, using a sound level meter.

Question 105

Describe sound pressure level used in environmental noise assessment and explain how it is calculated.

Answer 105

• The sound pressure level in dB is the ratio of the sound pressure level and a reference level at a point away from the source of the noise.
• Eqn in image
• Where,

p is the RMS sound level fluctuation of the sound of interest
p₀ is the reference sound pressure of audibility

• When sound pressure level is reported the location or distance from the source must be stated.
• The distance from the source and a host of other environmental factors influence the sound pressure level at a receiver.

Question 106

Referring to the generalized equation used in noise prediction models, list the important factors that affect noise propagation.

Answer 106

The generalized equation used in noise prediction models is in the image.

Where,

L_p = resultant sound pressure level at a point in the noise field
L_w = sound power level of the source
K_i (i=1, 2, 3…) = attenuation applicable (e.g. attenuation due to spreading, attenuation due to air absorption, barrier effects etc.)

The important factors affecting noise propagation are as follows:

• Distance from (attenuation due to spreading) source
• Type (point or line) of source
• Ground absorption
• Atmospheric absorption (dependent upon temperature and temperature gradient, pressure, relative humidity, wind and precipitation)
• Obstacles such as barriers and buildings
• Reflectors

Question 107

Referring to the generalized equation used in noise prediction models, briefly describe how attenuation due to spreading affects noise propagation.

Answer 107

• Sound is attenuated during its propagation through a medium. Therefore, the distance between the source and the receiver is an important factor in assessing noise environment.
• Over a distance, there are changes in the conditions of the medium and the terrain over which the sound wave propagates.
• Height of the source above the ground surface is also important.
• Attenuation due to spreading depends on the type of noise source.
• For spherical radiation from a point source attenuation is 6 dB per doubling of distance from the source.
• This holds true until ground and air attenuation noticeably affect the level.
• In the case of a line source, the sound level spreads out cylindrically, so the sound pressure level is the same at all points at the same distance from the line, and decreases by 3 dB per doubling of distance.
• This holds true until ground and air attenuation noticeably affect the level.

Question 108

Referring to the generalized equation used in noise prediction models, briefly describe how the type of source affects noise propagation.

Answer 108

• If the dimensions of a noise source are small compared with the distance to the receiver, it is called a point source e.g. fans and chimney stacks.
• In this case the sound spreads out spherically, so that the sound pressure level is the same for all points at the same distance from the source.
• If a noise source is narrow in one direction and long in the other compared to the distance to the receiver, it is called a line source.
• It can be a single source such as a long pipe carrying a turbulent fluid, or it can be composed of many point sources operating simultaneously, such as a stream of vehicles on a busy road.

Question 109

Referring to the generalized equation used in noise prediction models, briefly describe how ground absorption affects noise propagation.

Answer 109

• Sound reflected by the ground interferes with the directly propagated sound.
• The effect of the ground is different for acoustically hard (e.g. concrete or water), soft (e.g. grass, trees, vegetation) and mixed surfaces.
• Soft ground effects can produce additional attenuation of up to about 3 dB(A) over distances of 100m and this can increase with increasing distance up to about 9 dB(A) over 1000m.

Question 110

Referring to the generalized equation used in noise prediction models, briefly describe how atmospheric absorption affects noise propagation, and what it is dependent on.

Answer 110

• Over small distances (< few hundred m) atmospheric absorption can generally be ignored, as its effect is minor compared to that of spherical spreading.
• However, the effect is more marked over longer distances and high frequencies generally get attenuated far more than lower frequencies.
• It is dependent upon:
  
  • T and T gradient,
  • pressure,
  • relative humidity,
  • wind and
  • precipitation.

Question 111

Referring to the generalized equation used in noise prediction models, briefly describe how obstacles, such as barriers and buildings can affect noise propagation.

Answer 111

The noise reduction caused by a barrier depends on two factors:

• The path difference of the sound wave as it travels over the barrier compared with direct transmission to the receiver. A barrier is most effective when it is placed close to the source or the receiver.
• The frequency content of the noise – low frequencies are difficult to reduce using barriers.

In general terms if a barrier removes a source completely from the line of sight then a reduction of 10dB(A) is a reasonable estimate, and if the source is only half obscured then the reduction is only 5dB(A).

However, the maximum attenuation that can be afforded by a barrier is 20dB(A).

Question 112

Referring to the generalized equation used in noise prediction models, briefly describe how reflectors can affect noise propagation.

Answer 112

In the case of reflectors K must be added to the equation not subtracted.

Question 113

You are asked to predict and present a noise impact assessment report around a planned limestone quarry in a quiet area. How would you go about carrying out this study? Describe briefly, the steps you will follow in producing this report

Answer 113

• The first step, before modelling and assessing the impact of the planned limestone quarry, is to determine the background noise levels in the area over a prolonged period of time (preferably over 4 seasons, the longer the better), with many monitoring locations. Supplement with further spot readings using hand-held sound level meters if required.
• Generate background noise maps from the measured noise levels, introducing them into the GIS environment (integrate noise propagation model with GIS)
• Next, determine/estimate sound power level of the noise source (i.e. the quarry), evaluate attenuation factors and the combined analysis of these for the specific noise propagation path.
• Sound power level of quarry would need to be estimated using levels from the literature obtained at similar working and sized sites.
• Limestone quarry modelled as a point source due to its fixed position.
• Haulage routes, with individual noise sources moving over a fixed and known path modelled as line sources.
• Mobile or intermittently operating machinery, from which the generation of noise varies temporally and spatially depending on their operational schedule, modelled as distributed sources.
• Present the noise map produced for the Limestone quarry site after noise modelling.
• This map should include the effect of:
  
  • the background levels
  • the quarry site itself, which was modelled as a point source (as described), and
  • the haulage routes leading to and from the site, modelled as line sources
  • (and machinery modelled as distributed sources).

Question 114

You are asked to predict and present a noise impact assessment report around a planned limestone quarry in a quiet area. Describe briefly, the steps you will follow in producing the report for the limestone quarry specifically.

Answer 114

Limestone quarry modelled as a point source due to its fixed position.

Once the background levels are mapped and the sound power level (L_w) of the point source is defined, the following steps are executed:

1. Calculate attenuation due to geometric spreading.
2. Calculate attenuation due to air absorption.
3. Calculate attenuation due to ground effects.
4. Calculate attenuation due to topographic barrier effects.
5. Taking into account the point source sound power level (Lw) assumed and the attenuations calculated, calculate sound pressure levels (L_p) at each receiver location and combine the contributions from each source at this point to define the noise impact due to the limestone quarry.
6. Combine the quarry noise impacts with the background levels monitored and mapped at the beginning and present a noise map representative of the resultant noise levels.

Question 115

You are asked to predict and present a noise impact assessment report around a planned limestone quarry in a quiet area. Describe briefly, the steps you will follow in producing the report for the haulage routes (can be applied for roads also) specifically.

Answer 115

Road traffic, haulage routes, with individual noise sources moving over a fixed and known path modelled as line sources.

The modelling procedure applied to the prediction of road traffic noise is as follows:

1. Calculate the basic noise level (L_10,18h) for each road segment by implementing the necessary corrections for the mean traffic speed, percentage heavy vehicles and the road gradient.
2. Convert the basic noise levels (L_10,18h) to the EU recommended common noise indicators (L_den, L_day, L_evening, L_night).
3. Calculate attenuation due to distance for each road segment-receptor pair.
4. Calculate attenuation due to ground absorption for each road segment-receptor pair.
5. Calculate attenuation due to topographic barrier effects.
6. Taking into account the corrected basic noise levels and the attenuations calculated, calculate sound pressure levels (L_p) at each receiver location and combine the contributions from each road segment to define the noise impact due to haulage routes (road traffic).
7. Combine the anthropogenic noise impacts calculated with the background levels monitored and mapped earlier and present a noise map representative of the resultant noise levels.

Question 116

The human ear converts pressure fluctuations in the air into signals, which are transmitted by the auditory nerve to the brain where they are perceived as sound.

Describe why the sound level meters used in environmental noise monitoring require a frequency weighting adjustment. Explain, by giving examples, how frequency weighting works.

Answer 116

• As human perception of loudness varies with the frequency of sound, when assessing the subjective impact of noise on individuals both the sound pressure level and the frequency need to be taken into account.
• A noise appears to be louder if the concentration of energy is in the middle frequencies.
• In order to make a sound level meter respond more like the human ear a frequency weighting is applied to most environmental noise measurements.
• The weightings can be expressed as curves A, B, C and D by plotting frequency (Hz) on the x-axis vs dB on the y-axis.
• The most commonly used one is the ‘A’ weighting so that the response of the sound level meter is closer to that of the human ear.
• A ‘C’ weighting is used for assessing sound with low frequency content, and very loud sounds.
• All weightings have a flat response at 1000Hz, i.e. no correction is applied, since the ear’s response can be regarded as equal to that of the sound level meter at that frequency.
• However, at 63 Hz, for example, the ear’s response is down by around 26 dB, and so the ‘A’ filter takes off 26 dB at that frequency.
• Each frequency is considered independently in terms of its weighting,
• However, the levels can be logarithmically added to give an overall ‘A’-weighted figure which best represents the response of the ear.
• Most sound level meters will carry out this adjustment and can give values in terms of dB (linear) or dB(A).

Question 117

The Rapel River Basin in Central Chile offers a diverse geology, hosts intense mineral exploitation and agriculture, and exhibits marked seasonal variations.

Suggest which water contaminants you may expect to find in river waters and sediments.

Answer 117

• The pollutants released into surface water systems by natural and anthropogenic sources can be divided into categories of inorganic and organic compounds.
• The organic contaminants can be divided into 16 groups based on the function group C, H, S, N or P.
• The inorganic contaminants found in river systems are categorized in 3 groups:
  
  • Major constituents
  • Nutrients
  • Trace metals
  • Metalloids
• The concentrations of all these water pollutants define the water quality of a river or water body.

Question 118

Give examples of some of the important ‘organic contaminents’ and what are their associated problems?

Answer 118

• Polycyclic aromatic hydrocarbons (PAHs)
• Pesticides and polychlorinated biphenyls (PCBs).
• PCBs can persist in the environment for long periods of time and are classified as persistent organic pollutants (POPs).

Question 119

Polycyclic aromatic hydrocarbons (PAHs) includes:

Answer 119

> 100 different organic substances
that are known to pose potential toxic threat to humans and the natural environment.

Question 120

The POPs are of special concern to authorities since they:

Answer 120

• present strong propensity to accumulate in biota,
• they can be transported over long distances, and
• they can become toxic to humans and the natural environment at very low concentrations

Question 121

The major constituents are inorganic contaminants. What are their characteristics?

Answer 121

• Exist in natural water in conc. > 1 mg/L
• Include Ca, Na, Mg, K, SO₄, Cl, SiO₂
• Al, B, Fe and Mn of comparable concs act also like major constituents

Question 122

Nutrients are inorganic contaminants. What are their characteristics and why might they be problematic in excess?

Answer 122

• Essential for plants and living organisms
• Oxygen, nitrate (NO₃^-) and phosphate (PO₄^3-) linked to eutrophication (an excessive production of algae or plants in water caused by an enhanced nutrient supply).
  
  • The eutrophication process deteriorates the river water quality through deoxygenation since microbial communities break down the primary products of plant growth, or by the reduction in animal and plant diversity
  • High nitrate concentration in surface water also may cause methemoglobinemia in humans, which tends to inhibit the normal development of the central nervous system

Question 123

Trace metals are inorganic contaminants. What are they, and why might they be problematic?

Answer 123

• Trace metal refers to any metal found in low concentrations (<0.1 mg/L)
• Metal = chemical element that display cationic behaviour in aqueous solution, or has an oxide that is soluble in acids
• Most important from environmental point = Cu, Fe, Mn, Pb, Zn
• Even though Cu is an essential element, very low or elevated concentrations in surface waters may lead to deficiency or toxicity for aquatic organisms and human health (e.g. intestinal distress, liver and kidney damage, and anaemia)

Question 124

Metalloids are inorganic contaminants. What are they?

Answer 124

• Any element with intermediate properties between metal and non-metals
• As, Se, Mo important levels in surface waters

Question 125

Describe the kinds of sources of contaminants found in surface waters.

Answer 125

• The sources of contaminants are important in the characterization of surface water.
• Pollutants are released to surface waters from different sources, which are naturally occurring or anthropogenically driven.
• Although most of the degradation in water quality is due to human activity, there are natural processes and events that also diminish the water quality.
• The sources of contaminants that affect the water quality can be classified as point and non-point sources.
• Some sources can be classified as point and non-point. E.g. a mining site can be classified as an industrial land use and at the same time as point source since it provides wastewater discharges.
• The chemical characterization of sediments is also important to understand the natural and anthropogenic influence and sources of pollutants in river systems.

Question 126

What natural processes can diminish water quality?

Answer 126

E.g. torrential rain, evaporation in arid regions, thermal hot springs and natural mineralization can increase the concentration of the pollutants in water systems

Question 127

The sources of contaminants that affect the water quality can be classified as point and non-point sources.

What are point sources and what problems do they pose?

Answer 127

• Point sources allude to the release of chemical constituents from specific location, such as sewered and industrial wastewater discharges.
• The most important point sources correspond to domestic wastewater discharge and industrial discharge:
• Domestic wastewater discharges reduce the oxygen concentration in water, which causes a detrimental effect on the aquatic life and increase the level of nutrients stimulating the algae and plant growth
• The industrial wastewaters present high concentrations of nutrients, metals and toxic organic chemicals
• The discharge of animal feeding operations, where the animals are kept and raised in confined areas (hence point-source) are of special interest since they contribute high levels of organic material and modify water quality.

Question 128

The sources of contaminants that affect the water quality can be classified as point and non-point sources.

What are non-point sources and what problems do they pose?

Answer 128

• Non-point sources refer to chemical constituents that come from extensive areas of land and are transported overland, underground and through the atmosphere to the water.
• For that reason, the pollution from non-point sources is harder to identify, measure and regulate than that of point sources.
• Much of non-point source contamination takes place during rainstorms and following the spring snowmelt
• The most important non-point sources recognized to have a great impact on water quality are the agricultural and the urban run-off.
• The agricultural runoff is a primary source of surface water pollution since it contributes pesticides, herbicides and fertilizers.
• The application of fertilizers is a major concern because the associated nutrients, such as nitrates promote the growth of algae and plants.
• Erosion of the agricultural land can also adversely affect water quality
• Urban runoff contributes chemicals that are washed from the roads into the surface water.
• Atmospheric deposition also affects surface water quality and is considered non-point

Question 129

Urban runoff includes what chemicals?

Answer 129

• Petroleum components,
• Major elements e.g. Na+, K+, Cl-
• Metals e.g. Pb, Cd from automobiles
• Pesticides and nutrients used in gardens

Question 130

Why is the chemical characterization of sediments important in understanding the natural and anthropogenic influence and sources of pollutants in river systems?

Answer 130

• The stream sediments are composed of particles that have been transported and deposited on the floor of the stream, and precipitated material from chemical and biological processes.
• Sediment assessments are necessary to understand the pollutant distribution in streams for 3 main reasons:

1. Fine-grained particulate materials are natural sources of trace elements and organic matter, whose concs are strongly affected by the particle size and distribution of the sample,
   
   • i.e. increasing conc as particle size decreases.
   • T.f. large trace element concs may be found in sediment suspended and fine stream sediments
2. Sediment evaluation provides a time-integrated sample of particles transported by a stream, which is essential when pollutants cannot be detected by a single water sample because they are related to intermittent, storm or non-point events
3. Stream sediments reflect the potential bioaccumulation of trace elements and organic pollutants

Question 131

How can anthropogenic activities alter water and sediment chemistry, and what is the significance of this?

Answer 131

• Anthropogenic activities might alter water chemistry introducing metal compounds, organic pollutants and nutrients, which settle and accumulate in stream sediments.
• Under certain conditions these sediment-bound compounds may be released back to the water and, consequently, enter the food chain, rendering the sediment as point source.
• SO stream sediments represent both a sink and source of various metals for surface water

Question 132

Describe the two largest sources of waste products disposed into the environment as a result of metal mining activity.

Answer 132

• Mining activities increase the metal concentration in surface water systems to toxic levels and are an important point and non-point source for metals.
• Mining involves removal, processing and disposal of large volumes of rock and wastes.
• Mining areas are often surrounded by tailing impoundments, which contain pulverized material retaining water, and by waste rock dumps that contain high concentration of sulphide minerals that can potentially undergo oxidation.
• Emissions from smelters may contain SO₂ and metals, which may increase acidity and promote mobilization and accumulation of metals in downwind areas.
• Acid mine drainage is one of the major problems associated with mining and is produced when sulphide minerals, in particular pyrite, is oxidized releasing acid fluids that mobilise metals and metalloids in the leaching solutions.

Question 133

You have previously described the two largest sources of waste products disposed into the environment as a result of metal mining activity.

Expand on the nature and potential impacts of these metal mining wastes on the environment.

Answer 133

• When metals are released by oxidation and lixiviation processes, they can persist in the aquatic environment for long time.
• The mine water discharge presents elevated acidity and high concentration of metals.
• Since a fundamental feature of all trace metals is their tendency to partition between aqueous and solid phases, elevated metal concs found in waters, due to mining and mining-related activities, have also been observed in suspended, surface and sub-surface sediments.
• The effect of elevated trace metals in stream habitats may result in predominant organisms tolerant to high metal concentrations, and limited numbers of organisms and species in benthic communities.

Question 134

Mine water discharge presents elevated acidity and high concentration of metals, such as..

Answer 134

Fe, Cu, Zn, Co, Cr, Mn, Pb, Cd,

as well as major elements from the oxidation of silicate minerals, such as Ca, Mg, Na, Si, Al,

Question 135

What is an alternative way in which pollutant sources can be classified and why?

Answer 135

• The different sources of pollutants that affect water quality may be also classified according to the time of discharge in permanent or continuous, periodic, occasional and accidental.
• The receiving water bodies respond differently to these types of exposure e.g. rivers that receive continuous discharges, such as industrial wastewaters, may present acceptable water quality during the high-flow season, while during the low-flow season the maximum permissible pollutant levels may be exceeded.
• This is especially the case for contaminants that are related with the suspended material present and, therefore, also related with the erosion and flow regime.
• The latter phenomenon highlights the necessity to study the factors affecting the temporal and spatial variation of water chemicals in surface waters.

Question 136

Identify and briefly discuss the parameters that will affect the spatial and temporal variation of surface water quality

Answer 136

• The hydrodynamic features of the surface water as well as the regional geology and climatic conditions largely determine the observed spatial and temporal variation of surface water quality.
• The most important factor is related to the discharge regime, which depends on the specific geology, geography and climatic conditions of the watershed.
  
  • Most rivers exhibit base flow conditions (the minimum amount of water moving within a river) and generally is controlled by the groundwater discharge.
  • Snowmelt, storms, rainfall and soil saturation may increase the base flow resulting is an increase or decrease in the chemical constituents found in the water
• The behaviour of chemicals in relation to discharge depends of the chemical itself and on the hydrological features of the river. E.g.:
  
  • Major elements and nutrients, when their conc. is high, can exhibit a negative correlation with the discharge, which may imply increasing dilution of the chemical released at a constant rate.
  • Organic matter may display a limited increase in concentration as the flow rate increases, probably due to flushing of soils and erosion.
  • Total suspended particles (TSS) and the chemicals associated to particles can exhibit an exponential increase in conc. as the discharge rises
  • Cl (brought with rainfall) concentration may not exhibit change as the discharge increases.
• The extent of the spatial variation in water quality and the complexity of factors that affect it depend on the scale of the study area and the presence of natural and anthropogenic pollution sources

Question 137

The temporal variation in water quality can be classified into what 5 categories?

Answer 137

1. Minute-to-minute and day-to-day differences
   
   • As a result of water mixing due to meteorological conditions
   • E.g. river floods
2. Diurnal variation
   
   • Due to biological cycles and daylight-darkness cycles
   • The pH and dissolved oxygen content may be sensitive to these cycles
3. Day-to-month variations
   
   • Related to the flow regime and contaminant sources
4. Seasonal hydrological and biological cycles
5. Year-to-year variation
   
   • Mainly related to human activities in the catchment

Question 138

Using Cu2+ as an example, provide a sketch of the main geochemical processes affecting the bioavailability of trace metals in aquatic systems.

Answer 138

Question 139

What are the main geochemical processes that affect the bioavailability of trace metals in aquatic systems.

Answer 139

• The behaviour of trace metals in aquatic systems is highly complex, due to the large amount and different kind of reactions with dissolved and particulate fractions and non-equilibrium conditions.
• Trace metal added to the natural water could be partitioned among various constituents;
• A fraction will be associated with dissolved inorganic and organic ligands in solution;
• A fraction will be associated with the particulate material following absorption, precipitation, co-precipitation or uptake by living organisms.
• Consequently, a major fraction of the trace elements will become attached to bottom sediments.
• The distribution, mobility, bio-availability and toxicity of chemical elements depend not simply on their conc, but critically on their forms (isotopic composition, oxidation or electronic state; and/or complex or molecular structure), which determine the physical and chemical association that they undergo in natural systems.
• Changes in environmental conditions, whether natural or anthropogenic, influence the behaviour of both essential and toxic elements by modifying the form in which they occur, and changing their partitioning between sediment and water.

Question 140

Provide a brief description of how metal interaction with water ligands affects the bioavailability of trace metals in aquatic systems.

Answer 140

• Dissolved species in water occur as free hydrated ions and aqueous complexes.
• The term complex refers to a dissolved species that is formed by the association of a cation and an anion or a neutral molecule/ligand.
• Cu²⁺ and other similar elements are prone to exist in complex forms, rather than as free hydrated ions, modifying and reducing their toxicity, reactivity and also mobility.
• This effects the ‘environmental availability’ (external bioavailability)

Question 141

Provide a brief description of how metal interaction with particulate matter affects the bioavailability of trace metals in aquatic systems.

Answer 141

• Toxic metal concs are generally limited by sorption onto the surfaces of minerals and onto organic matter.
• There are 3 main mechanisms through which metals can be bound to PM:
  
  1. Adsorption
  2. Precipitation
  3. Ion exchange
• This affects the environmental availability (external bioavailability)

Question 142

Provide a brief description of how the mobility of chemical elements affects the bioavailability of trace metals in aquatic systems.

Answer 142

• Controlled by several factors, such as pH, solubility reactions, sorption, and redox conditions
• Ionic potential
  
  • Elements with low ionic potential are usually mobile and exist as simple cations e.g. Ca²⁺, K⁺, Na⁺
  • Elements with high ionic potential can exist as mobile oxyanions e.g. SO₄^2-, PO₄^3-
  • Elements with intermediate ionic potential tend to be sorbed or hydrolysed, exhibiting low solubility and t.f. low mobility
• Metal complexation also has a direct effect on metal adsorption on mineral surfaces or the organic matter
• This process affects the environmental availability (external bioavailability)

Question 143

Provide a brief description of how metal interaction with organisms affects the bioavailability of trace metals in aquatic systems.

Answer 143

• Metals may be incorporated in aquatic species through 2 major pathways or up taking vectors:
  
  1. The ingestion of metal-enriched sediment and suspended particles during feeding
  2. The metal uptake from solution
• This affects the ‘environmental bioavailability’ (internal bioavailability)

Question 144

Bioavailability processes are defined as…

Answer 144

…the physical, chemical and biological interactions that determine the exposure of plants and animals to chemicals associated with soil, sediment or water.

The bioavailability is a complex process and several factors, abiotic and biotic, play a key role in the determination of the available fraction, which is responsible for adverse effects to the biota.

Question 145

Changes in environmental conditions, whether natural or anthropogenic, influence the behaviour of both essential and toxic elements by modifying the form in which they occur, and changing their partitioning between sediment and water.

The latter processes are controlled by many factors, such as:

Answer 145

• pH,
• redox potential,
• concentration of the major cations,
• alkalinity and hardness,
• dissolved organic and inorganic ligands,
• ionic strength,
• the presence of particle surfaces for adsorption, and
• colloidal matter

Question 146

What does ‘environmental bioavailability or external bioavailability involve?

Answer 146

The partition of chemical elements in water and its interaction with the solid fraction, which depends on the physiochemical features of the aquatic environment.

Question 147

What does the environmental bioavailability or internal bioavailability relate to?

Answer 147

Relates the physiological driven uptake and is related with the biotic factors, such as taxonomy, nutrition or acclimation

Question 148

Discuss the methods for chemical monitoring and assessment of water quality.

Answer 148

• Simple data gathering techniques such as grab sampling are often used for the evaluation of water quality
• The assessment of water quality starts with the collection of appropriate information, referred to as water quality monitoring, which can be divided into three categories depending on the objective of the assessment:
  
  • The monitoring programmes involve long-term standardised measurement of the aquatic system, so that the water quality trends and status can be defined
  • The survey programmes imply the measurement during a limited period of time for a specific purpose.
  • Surveillance programmes involve continuous measurements of the water quality in order to manage and define operational activities.

Question 149

The common objectives of preliminary survey programmes in the assessment of water quality are:

Answer 149

• To determine the spatial and temporal variability of the water quality parameters, so that the behaviour of the water environment can be understood and hence the location of the sampling station(s) and the frequency of monitoring can be specified;
• To determine the key processes controlling water quality; and
• To assess the feasibility and cost of the monitoring programs

Question 150

Explain the process of quality control assessment specifically referring to stream water and sediment monitoring.

Answer 150

• Because we can only measure a small amount of material of interest in a sample, the measurement of it is affected by:
  
  • the sample collection,
  • the sample preparation, and
  • the chemical analysis
• Cross contamination during these processes might produce over-estimation or underestimation of the concentration.
• The measurement uncertainty needs to be studied in order to evaluate whether the chemical data is reliable.
• This is attained by collecting quality control samples, such as blank, duplicate or reference material samples
• Involves the identification of parameters which have high uncertainty or exceed the minimum precision requirement
• If the measurement conditions and the source of uncertainty are poorly constrained, the uncertainty of the stream flow and water quality data can increase dramatically

Question 151

What information can be provided by quality control samples, such as blank, duplicate or reference material samples?

Answer 151

• Provide information on the variability and the usability of the data;
• Indicate field sampling or laboratory errors
• Provide the basis for future validation and use of the analytical data

Question 152

Specifically referring to quality control sampling during stream water and sediment monitoring, what is a ‘blank’ sample?

Answer 152

Blanks provide a measure of bias that could be present as a result of contamination of environmental samples by analytes of interest during any stage of water sample collection.

Water blank samples comprise ultraclean deionised water that is intended to be free of the analyte of interest.

Question 153

Specifically referring to quality control sampling during stream water and sediment monitoring, what is a ‘duplicate’ sample?

Answer 153

Duplicate samples determine the reproducibility or consistency, and provide a measure of the variability introduced during sample processing and analysis.

The field duplicates are collected from the same source, preserved, transported and documented identically, in the same manner as the rest of the sampes.

Question 154

Specifically referring to quality control sampling during stream water and sediment monitoring, what is a ‘reference’ sample?

Answer 154

Reference samples measure the accuracy of the laboratory analytical process.

Question 155

What is the purpose of having Environmental Sampling Protocols in the chemical monitoring and assessment of water quality?

Answer 155

• As a consequence of the spatial and temporal variability exhibited by the surface water, the collection of representative samples has become quite complex.
• Contamination introduced during sample collection, transport, handling and storage will modify the physiochemical properties of the sample and, therefore, affect the water quality and toxicity assessment.
• Standardised sampling methods permit to:
  
  • obtain consistent, reproducible data,
  • facilitate temporal comparisons among sampling campaigns, and
  • help avoid contamination.

Question 156

What are the basic principles relevant to environmental sampling campaigns/protocols?

Answer 156

• It is essential to include ultraclean/clean sampling, handling and analysis techniques, in order to obtain reliable and consistent trace element information for the aquatic environment.
• In some cases, reduced metal levels measured have more to do with improved sample handling and analysis rather than real environmental improvements
• Through the use of these techniques, is it possible to detect and determine small variations and low metal concentration levels.

Question 157

Ultraclean/clean sampling techniques include the following procedures:

Answer 157

1. Use equipment which was constructed with uncontaminated material and rigorously cleaned before the sampling
2. Handle equipment and samples in such a manner which minimises contamination and alteration of natural element concentration
3. Collect routinely quality-control samples, which ensure a high degree of confidence in the information collected for an environmental survey.

Question 158

Give some examples of point sources for contaminants at a mine.

Answer 158

wastewaters, runoff from industrial site, runoff and drainage water from active mine

Question 159

Give some examples of non-point sources for contaminants at a mine.

Answer 159

outflow from abandoned mines, industrial land use

Question 160

Referring to your field work at Tara Mines, describe the environmental monitoring systems one should employ in ensuring environmental compliance in managing a tailings facility.

Answer 160

• Environmental implications high on Tara agenda, particularly because mine is so close to the town of Navan (population 35k) with the important river Blackwater running through.
• Tailings facility at Tara is not technically lined, but fit with a natural clay liner. Naturally, this layer has weaknesses (pockets of sand) and is leaking in a few places.
• The locations and extent of leakage is known, in a steady state, is not leaching any heavy metals or harmful chemicals and is of no risk to human health.
• Under the terms of Tara’s IPPC licence, all environmental aspects of the company’s activities are monitored including:
• Continuous monitoring of:
  
  • Noise at 6 locs
  • Blast vibration at 6 locs
  • Ambient air, and
  • Total dust deposition
  • Tara’s licenced effluent discharge to the River Boyne (1 loc) on a daily basis
  • Sheep/livestock grazing trails on the revegetated Tailings surface.
• Routine monitoring, carried out in the environments of the mine and TMF (Tailings Management Facility) in which samples are taken at regular intervals in time to study the cumulative effects. These include
  
  • Grab sampling techniques:
  • Water sampling procedures in ISO 5667 provide the guidelines for water monitoring decisions.
  • Groundwater from test boreholes on a monthly basis at 30 locs
  • Surface water from 17 sampling locations covering all rivers and streams on a monthly basis
    
    • Electrofishing
  • Air monitoring
  • Soil and vegetation (extensive and annual)
  • Animal health surveys
    
    • Electro-fishing (five-yearly since ‘70’s) on River Boyne
    • Veterinary / animal health studies
• Surface water, groundwater and air sampling is sublet to a contractor at Tara now.

Question 161

Referring to your field work at Tara Mines, describe the continuous biological monitoring systems should employed in ensuring environmental compliance in managing the tailings facility.

Answer 161

• Sheep/livestock grazing trails on the revegetated Tailings surface.
• Such a system can be describe as continuous as the organisms are constantly exposed to the effects of the environment around them.
• This types of technique has the advantage that it can often be used to observe the actual direct impact of changing conditions upon the environment.
• Tara have outside expertise and cooperation from farmers of different agricultural disciplines (e.g. sheep farming, dairy farming, crops), and then take samples from their produce to check for contamination.

Question 162

Referring to your field work at Tara Mines, describe the groundwater monitoring systems employed in ensuring environmental compliance in managing the tailings facility.

Answer 162

• Grab sampling
• Tailings facility at Tara is not technically lined, but fit with a natural clay liner. Naturally, this layer has weaknesses (pockets of sand) and is leaking in a few places.
• Since all mine-influenced water is high in sulphate sourced from zinc, lead and iron sulphides (700 - >1000 mg of sulphate vs <30-40 mg naturally in the area), sulphate can be used as an indicator substance to tell where under the influence of leakage. T.f. measure conductivity!
• Ground-water pollution into River Blackwater t.f. wells on that side of the mine are most important.
• Drinking water in Navan all from the River Blackwater. An environmental disaster effecting this river would destroy drinking water of Navan
• Extensive network of sampling points (30 test boreholes for whole site)
• 16 groundwater monitoring locations in environment of tailings storage facility
• Changes in trends over 10-40 years

Question 163

Referring to your field work at Tara Mines, describe the surface water monitoring systems employed in ensuring environmental compliance in managing the tailings facility.

Answer 163

• Grab sampling of spot samples
  
  • Instantaneous water hydro-chemistry
• Laboratory analysis
• 17 surface water sampling locations covering all rivers and streams (monthly)
• Monitoring also numerous smaller streams that connect to the river
• Background samples (reference samples) taken upstream of facility (at point A) to gage influence (already polluted?) and compare vs samples taken downstream of facility (at point B)
• Old landfill (annually, 8 locs)
• Domestic wells (bi-annually, 12 locs)
• Electrofishing
• All water is collected and treated prior to release if decanted into Boyne river
  
  • Significant river in Ireland – drinking water source for people downstream of Navan

Question 164

Referring to your field work at Tara Mines, describe the air monitoring systems employed (in ensuring environmental compliance in managing the tailings facility).

Answer 164

• Grab sampling
• Ambient
  
  • Dust (monthly, 12 locs)
  • Ambient air (monthly, 6 locs)
• (Emissions)
  
  • Stack monitoring/sampling (isokinetic) (weekly, 1 loc)
  • RARs (Return Air Raises / mine ventilation) (weeky, 5 locs)
  • Boilers (annual, 3 locs))

Question 165

Referring to your field work at Tara Mines, describe the soil and vegetation monitoring systems employed (in ensuring environmental compliance in managing the tailings facility).

Answer 165

• Annual extensive grab sampling
• Sediment chemistry – e.g. study of soil contamination
• Sedimentation

Question 166

Referring to your field work at Tara Mines, describe the animal health surveys employed in ensuring environmental compliance in managing the tailings facility.

Answer 166

• Studies designed to examine the health and sustainability of aquatic life in rivers and streams in the vicinity of the Randalstown tailings facility carried out between 1992 and 2009.
• Electro-fishing (five-yearly since ‘70’s) on River Boyne
  
  • Fish samples taken from above and below point of discharge into river (the most sensitive area)
  • Estimate fish population and quality
  • Surveyed by electro-fishing a stretch of water (trout and salmon are most susceptible to pollution)
  • Statistical interpretation for every survey – validate for each year and compare between surveys.
  • Requires licence.
  • Measure fish size, blood, organs (kidneys, liver – in order to see if the fish are picking up heavy metals)
  • Most fish re-released unharmed
• Veterinary / animal health studies

Question 167

Referring to your field work at Tara Mines, describe why it’s important to employ ground vibration monitoring techniques in ensuring environmental compliance in managing the facility.

Answer 167

• Blast vibration twice a day
• Development blasting in morning / production blasting in evening
  
  • By far the biggest source of complaint – people living near/over the ore body feel the ground shaking in short sequential bursts of waste energy to surface – 2-3 complaints every month
  • Ore body stretches 4km into rural hinterland where there is more dispersed people living
  • people think cracks in their walls/ceilings are caused by the blast vibration – Tara more than reasonably comfortable that this is not the case

Question 168

What is the role of the environmental department at Tara Mines?

Answer 168

• Environmental implications high on agenda at Tara Mines due to EU regulations and particularly because the mine is so close to the town of Navan which has a population of 35k.
• All drinking water in Navan comes from the River Blackwater, and so an environmental disaster effecting this river would be devastating.
• At Tara Mines, there are 3 full-time personnel whose core responsibilities are environmental monitoring and control.
• The primary role of the department is to ensure that Company activities are carried out in accordance with the conditions of the environmental operating licence (IPPCL) and that the Company’s core values towards the environment is sustained.
• At its instigation in 1971, Tara planned and executed an extensive baseline study of existing environmental conditions.
• These studies have provided vital information in establishing natural conditions and base standards upon which the mine now operates
• Everything that is done at Tara mines is governed by the Irish Environmental Protection agency (EPA) – responsibility for enforcing environmental control
• Closure plan for Mine Site & TSF
  
  • 30 years of aftercare
  • 15 million euro fund in trusts or bonds with local authorities (outside control of company) so that if company goes under they can’t just pack up and leave – clean up money
• Not just about monitoring and complaints - Research projects – some on tailings dam:
  
  • E.g. Vegetation trials to establish which species of grasses were most suitable to grow on the tailings surface

Question 169

At its instigation in 1971, Tara planned and executed an extensive baseline study of existing environmental conditions.

These studies provided vital information in establishing natural conditions and base standards upon which the mine now operates.

Considering these base standards, what techniques are used to decrease Tara’s impact (visual or otherwise) on the sourrounding town and countryside

Answer 169

• Considerable emphasis was placed on architectural compatibility with the surrounding countryside, so that from the outside perspective the mine looks relatively normal. The concentrator, for example, was sunk 3m into solid rock to reduce the visual impact of the high profile buildings
• The colour scheme for the pre-finished metal panels were designed to be complementary to the surrounding landscape.
• Noise control was a critical factor in the layout and final design of the complex with acoustic berms built.
• An extensive landscaping programme (banks and trees) reduces the intrusion on the flat landscape of the area.

Question 170

What are Water Quality Standards?

Answer 170

• Water quality standards are defined as the maximum level of a substance in a particular medium (i.e. water, sediment or biota), which will not be detrimental when the medium is used continuously for a specific purpose
• The acceptable quality of natural water body depends upon its present and future beneficial use

Question 171

The water uses can be classified in the following groups:

Answer 171

• Recreational
• Wetland
• Groundwater
• Navigation
• Agriculture
• Domestic water supply
• Aquatic life

Question 172

There are 3 general water quality standards that are defined according to their use. What are they?

Answer 172

• Surface and groundwater standards (ambient quality standards)
  
  • Designed to protect the uses of the natural waters
• Effluent standards
  
  • Designed to control the discharge of industrial an wastewaters into natural waters
  • Based on the best available and economical technology for treatment
• Drinking water standards
  
  • Designed to protect the public health

Question 173

The water quality standard criteria for surface water are generally considered from what two viewpoints?

Answer 173

• Human health criteria derived from:
  
  • assumptions related to the degree of human contact and quantity of water ingested during human contact
  • experimental dose-response relationships and acceptable risk.
• Aquatic life criteria derived from:
  
  • mortality studies of certain organisms exposed to various level of pollutant water

Question 174

The study of the particulate fraction, suspended particle and fluvial sediments, is also important in water quality assessment since they:

Answer 174

• influence the concentration of chemicals in the water column,
• induce bioavailability, and
• Have an effect on metal transportation and distribution processes.

The changes in concentration and partitioning of metals between dissolved and particulate forms are linked to changes in key transport factors, such as the organic matter and suspended particulate material.

Question 175

What are the main tasks to be carried out in EIA?

Answer 175

1. Investigation of proposed site(s) and surrounding physical, ecological, social and economic environment;
2. Conduct of basline studies and identification of on-site and off-site environmental conditions, currently and in future, without the proposed development;
3. Detailed analysis of the workings of the proposal, including its various phases, functions, and connections with the environment;
4. Investigation of mitigation measures;
5. Prediction of environmental impacts of the proposed development;
6. Analysis of alternatives to proposed action, including environmental effects;
7. Evaluation of development alternatives and environmental protection measures;
8. Indication of recommended course of action for implementation of the proposal, including environmental monitoring, environmental management and post-development provisions.

Question 176

What are the main steps of EIA Procedure?

Answer 176

1. The developer formulates the proposal.
2. The proposal is submitted to the Local Planning Authority who assess the significance of the likely environmental impacts of the activity.
3. The Planning Authority considers the scope and programme for an EIA and notifies the Environment Authority.
4. The Environment Authority determines the appropriate level of EIA
5. A detailed EIA is undertaken and documented in an EIS.
6. A public inquiry or review may be held to enable citizens to comment on the contents of the EIS and useful comments are incorporated.
7. The EIS, and the proposed mitigator and monitoring programme are reviewed by the Environment Authority.
8. The final EIS is prepared, including a full account of mitigation and monitoring measures.
9. The Planning Authority makes the decision to proceed or cancel.
10. A post-audit is undertaken to determine accuracy of the predictions and to see whether mitigation measures were properly carried out.

Question 177

EIA Procedure includes the undertaking of a detailed EIA which is documented in an EIS.

What should the EIS (Environmental Impact Statement) contain?

Answer 177

• A description of the proposed activity;
• A description of feasible alternatives;
• A description of the potentially affected environments;
• An assessment of all the likely or potential environmental impacts (including cumulative, direct, indirect, short and long term effects) of the proposed activity and alternatives;
• An identification, description and assessment of mitigation measures for each alternative;
• An account of provision for post-audit.

Question 178

The chemical quality of surface water varies due to several factors such as

Answer 178

geology, human activities, climate and distance from pollution sources.