Bicol UniversityCollege of Engineering

Mining Engineering DepartmentLegazpi City

Report

on

QUARRYING AND ITS ENVIRONMENTAL EFFECTS

Submitted to:Ms. Indira B. Tabo

Professor

by:Julius Banez

Sarah Mae AjonJan Rose Bilolo

Jhocel MarollanoDailyn Nivero

BSEM – 2

March 24, 2010

ABSTRACT

Aside from steel bars, rocks and other cement materials are used for building

construction. These stones are dig up from different sources such as mountains, plains

and river beds. After that they are transported to the processing or crushing plants in

order to be converted to cement such as portland cement or crushed to an appropriate

size like sand-sized rocks. Different types of stones can be excavated; in example are

small rocks such as pebbles, bigger rocks such as cobbles, and the biggest of the three

such as boulders. Though it is similar to and classified under mining, this industry is

different, it is called quarrying.

Forces shape the earth’s surface, and there is a great force of man’s invented

industries that can alter gradually the different landforms. Quarrying is one of them, and

it is also one industry that thrives here in this country. It has different impacts which can

affect people and the environment itself. Focusing on the environmental impacts, it can

provide direct damage to people by inhaling dust, and listening loud sounds. Indirect

effects can cause different calamities such as landslides and flashfloods. Thus, it is

appropriate that certain laws and standards must be implemented to mitigate the

impacts.

Air pollution is one of the major effects of quarrying. Dust is the most common

and the most extensive air pollutant from a quarry. It has different origins in a quarry site

such as mechanical handling operations that include crushing and grading process;

haulage with which is related to the vehicle, and the nature and condition of the way;

blasting; additional manufacturing operations and wind blow from paved areas,

stockpiles etc. Dust concentration levels are monitored in two ways, active monitoring in

which the system is suited to measuring over minutes, hours and days; and passive

monitoring which are suited for measuring over days, weeks and months. Some ways

for mitigation of dust emission are to consider the planning conditions relating to the

layout of the site, design of stockpiles, hard surfacing of vehicle areas, containment of

conveyors and processing plant and dust collection equipment, use of moistening

equipments on the dusty places, design of material-handling systems, provision of

monitoring facilities, and measurement of limiting levels of dust.

Quarrying generates significant amount of noise in its different activities. It starts

from the starting phase such as establishment of roads to the site, construction of

buildings and facilities. In some instances the next process involves the exposing of the

valuable rock or mineral by using scraping equipments to remove the top soil and other

layers. The excavation of the mineral contributes more noise than by use of machinery

to transport the materials and sometimes having processing plants to crush and grade

the materials. Some quarries use explosives to break away rocks in which is called

blasting. This activity creates great amounts of noise in the environment, that’s why

there are also monitoring systems used in blasting. The companies using the blasting

process must comply with the standards mandated by the law.

Damage to biodiversity is also imminent by which the natural habitat as well as

the species it support is destroyed. There’s no helping that the habitat can be

destroyed, but when the quarry closes it must be ensured that the site will be fully

reclaimed and the habitats recovered. Some of the things that may need to consider are

having to implement a comprehensive baseline study of the ecosystem; to make a

safeguarding or creation habitat; to make use of the buffer zones between workings and

sensitive habitats; to have progressive working and restoration; to provide alternative

habitats for defined species; and to transplant valuable flora as a last resort. It may also

help by implementing methods that can mitigate the other impacts of quarrying because

it can indirectly affect wildlife.

Wastes are by-products of extraction and processing in which is highly

unavoidable but are generally inert and non-hazardous. They are generally stored in soil

heaps known as tip which is either temporary to be re-excavated or permanent to be

used as auxiliary designs for the final long-term landscape on closure and restoration of

the land. Quarry fines are a mixture of coarse medium and fine sand material, and silt or

clay(silt and clay is known collectively as filler) in which if there are higher percent of

sand, silt and clay, the more difficult it is to handle due to easy mobilization in gravity,

wind and water. There are many ways in which quarry wastes can be mitigated, by

minimization of the production of waste, reusing the waste by harnessing it as part of

the program for progressive restoration, site waste heaps having regard to effects on

the landscape, groundwater, surface watercourses, and flood regime, encasement of

waste with physical or chemical contaminant, cementation of fine waste and the use of

waste for beneficial reasons such as using as a part of progressive restoration.

Right planning and management can contribute for the minimization or control of

these effects. It is important to know and implement the standards set by the laws and

to provide additional methods in improving the mitigation process. The environment can

be enhanced through restoration of the land after the cessation of quarry operations.

THE ENVIRONMENTAL EFFECTS OF QUARRYING

I. INTRODUCTION

Quarrying is the process of obtaining quarry resources, usually rocks, found on

or below the land surface. The difference in mining and quarrying is that quarrying

extracts nonmetallic rocks and aggregates while mining excavates the site for mineral

deposits. Some of the stones extracted were sandstone, limestone, perlite, marble,

ironstone, slate, granite, rock salt and phosphate rock. The suitability of the stone for

quarrying depends on (1) its quality; (2) the possibility of cheap and ready conveyance

to a large market; and (3) its inclination and depth below the surface.

The two principal branches of the industry are the so-called dimension-stone and

crushed-stone quarrying. In the former, blocks of stone, such as marble, are extracted

in different shapes and sizes for different purposes. In the crushed-stone industry,

granite, limestone, sandstone, or basaltic rock are crushed for use principally as

concrete aggregate or roadstone.

There are also different methods of quarrying which are affected by the

topography of the site, type of rock to be extracted, and use of equipments. The

following statements present the different methods of quarrying. In some instances

explosives are used to break large rocks and later crushed to an appropriate size. In

this method holes are drilled in the rocks and are filled with explosive. It is detonated

through the electric firing or other methods of blasting.

Channeling and wedging is another process of quarrying in which channeling

machines are used in cutting long, narrow channels in rock which is deep enough for

the insertion of wedges. The rock is then split through the fracture. The channeling and

wedging process of quarrying is extensively used in quarrying marble, sandstone,

limestone and other softer rocks, but is not successful for granite and other hard rocks.

Another method of cutting is by the combination of a power saw, an abrasive, and water

as a lubricant and a coolant. The saw cuts a narrow channel, the primary or initial cut,

that is then either expanded by a wedge or is blasted. This method is used in slate,

granite, and limestone quarries.

The most common and simple method is the use of hand tools such as pick,

shovel, and wheelbarrow. It is commonly used in easily accessible beds such as loose

rocks in riverbeds, and soft rocks in the mountains that can be easily broken down.

The purpose of this report is to present the different environmental effects of

quarrying, and the methods of mitigating it. It aims to increase awareness to the people

involved in quarrying and those who might be affected by it. Thus, helping them to

understand the effects and provide plans in order to uphold responsible quarrying.

This report lists the possible obvious effects of quarrying. The four parts of this

report involves the major environmental effects of quarrying like air pollution, noise

pollution, damage to biodiversity, and quarry wastes. It also discusses about the

different mitigation methods and the different good practices that are being implemented

in assistance to the reduction of each impact.

II. AIR POLLUTION

Definitions

Dust is considered to be any solid matter emanating from a surface mineral

working, or from vehicles serving it, which is borne by the air.

Dust is particle of matter in the size range of 1 - 75μm in diameter, with particles

less than 1μm being classified as smoke or fumes. The finest particles of between 1 and

10μm in diameter will be respirable and are associated with health effects. Particles

greater than 10m are associated with public perception and nuisance.

Nuisance dust may be described as the coarse fraction of airborne particulates, typically

greater than about 20 μm, although there is no standard definition.

Sources of Dust

Dusts are normally present in the atmosphere, at varying levels of concentration

and can have a wide variety of man-made and natural origins including:

products of combustion from e.g. fires, power stations and motor vehicles;

mechanical handling of minerals and allied materials;

industrial activities;

matter resulting from volcanic action, desert storms or other geological activities

sea-salt from oceanic processes.

It is important to recognize that there are a number of sources of dust which will

not be connected to a mineral working. These will not always be readily distinguishable

from site dust and so may give rise to unwarranted complaints.

Dust Emission

Dust particles are dispersed by their suspension and entrainment in an airflow.

Dispersal is affected by the particle size shape and density, as well as wind speed and

other climatic effects. Smaller dust particles remain airborne for longer, dispersing

widely and depositing more slowly over a wider area. Large dust particles (greater than

30 μm), that make up the greatest proportion of dust emitted from mineral workings will

largely deposit within 100μm of sources. Intermediate sized particles (10 - 30 μm) are

likely to travel up to 200 - 500μm. Smaller particles (less than 10 μm) which make up a

small proportion of the dust emitted from most mineral workings are only deposited

slowly. Concentrations decrease rapidly on moving away from the source, due to

dispersion and dilution.

The process by which dust becomes airborne is referred to as 'dust emission'.

For this to happen, energy is required to overcome the gravitational and cohesive forces

binding dust particles to the surface. Potential dust emission that may be associated

with mineral workings can be caused by:

mechanical handling operations, including crushing and grading processes

where in general the more powerful the machinery and the greater the volumes

of material handled the greater the potential for dust emission;

haulage, where the weight of vehicles, their speed of passage and number of

wheels in contact with the ground, and the nature and condition of road surfaces

or haul routes all affect the amount of dust emitted;

blasting;

ancillary "manufacturing" operations within quarries (batching plants, concrete

plants, asphalt plants etc.);

wind blow from paved areas, stockpiles etc.

Extent of the Problem

The amount of dust generated and emitted from a mineral working and the

impact on the surrounding area varies with respect to the following factors:

the types and quantity of mineral and the method of working;

the types of processing activities undertaken on a site;

the character and land use of the area surrounding the site;

the hydrogeology of the site and the vegetation cover;

climate/local meteorology and topography;

dust control measures employed on the site.

The variation in potential dust impacts between different mineral types is

accounted for by a number of factors:

the scale of operations: generally the more extensive the scale of operations,

the more likely that dust will be a concern,

the nature of the mineral: although softer minerals crumble more easily during

handling and may produce a greater number of dust particles, intensive handling

of hard minerals may produce large amounts of dust due to higher energy inputs,

the color and opacity of the mineral: high contrast dust from minerals, such as

coal or limestone are generally more likely to be noticed on deposition,

length of operation: a potential dust problem may be more acceptable if it is

known that operations will soon cease or move to another part of the site,

the type of activities undertaken within a site and the location and duration

of those activities, and

the chemical nature of the dust: will affect the severity of the impacts upon

soils and vegetation.

Dust Impacts

Ecology and agriculture

There are few detailed studies of the effects of dust deposition on ecology and

agriculture. The effect that dust will have is determined by a number of variables,

including:

the concentration of dust particles in the ambient air and its associated

deposition rates. Characteristics of the vegetation and leaf surface can influence

the rates of dust deposition on vegetation, such as surface roughness and

wetness;

meteorological and local microclimate conditions and degree of penetration of

dust into vegetation;

size distribution of dust particles;

dust chemistry - ranging from highly alkaline dusts e.g. from limestone quarries,

to inert dusts, and acidic dusts, such as dusts from coal workings.

Dust may have physical effects on plants such as blockage and damage to

stomata, shading, abrasion of leaf surface or cuticle, and cumulative effects e.g. drought

stress on already stressed species. The chemical effects of dust, either directly on the

plant surface or on the soil, are likely to be more important than any physical effects.

Dust deposited on the ground may produce changes in soil chemistry, which may in the

longer-term result in changes in plant chemistry, species competition and community

structure.

Many substances, such as chalk and limestone have traditionally been used in

agriculture to increase crop sensitivity. Dust deposition levels are likely to be well below

the level of agricultural applications, and therefore effects on agricultural crops are likely

to be minimal. Areas of high ecological value or agricultural resources may be more

sensitive to dusts than other areas. Examples of sensitive areas include designated

nature conservation areas containing sensitive species, intensive horticultural areas,

and fruit growing areas.

Nuisance effects

Nuisance dust is the larger size fraction that is visible in the atmosphere. Dust

effects on people have been identified as arising from increases in airborne dust

concentrations, and deposition levels. Dust depositions on windows, on the outside of

the house, and on cars are the most frequently mentioned reasons for concern. The

table lists the factors that can determine whether surface soiling by dust is considered a

nuisance.

Surface soiling by dust as a nuisance.

Deposition on a surface which is usually expected to remain free from dust

The color contrast between the deposited dust and the surface upon which it settles

The nature of the illumination of the surface - "dinginess"

The presence of a nearby clean 'reference' surface against which comparison may be made

The rate of change in the visual properties of a surface

The identity of the area and the composition of the local community social factors, such as lifestyle and patterns of working

The personal experiences and expectations of the observer

The rate of deposition and therefore the time taken for dust deposition to become

visible are important influences on the perception of dust. The rates of deposition vary

widely with emissions, variations in wind speed and direction and also variations in the

background dust concentration. These background levels will determine the reaction of

local people to any additional dust from specific mineral sources, together with the

following three factors:

the frequency of dust deposition incidents. A community may be prepared to

tolerate an incident once a month, but not repeated incidents at frequencies of

one or two a week;

the amount of deposited dust. The amount of dust will usually decrease with

distance, so the proximity to the source will be a major factor in the determining

the level of complaint.

the area affected by deposition. If the emissions increase then there is the

possibility of a larger area being affected. This will increase the probability of

complaint unless the dust is diluted to a point below which people are concerned.

One of the problems is how to quantitatively measure the rate and severity of

soiling. A number of methods are described later which will avoid dependence on

subjective descriptions and complaints.

Health Effects

Particulate air pollution is associated with a range of effects on health (from

particles less than 10m in diameter, known as PM10) including effects on the respiratory

and cardiovascular systems, asthma and mortality. Detailed studies have been and

continue to be made on the actual level of impact on health. Work published in 1999 by

the University Of Newcastle Department Of Epidemiology and Public Health,

investigating the impact of particulate matter from opencast workings on public health,

found:

opencast coal mining was associated with a small increase in the mean

concentration of airborne particles measured as PM10 in areas close to opencast

sites. This was due to an increased concentration of shale rather than soot;

the respiratory health of children living in communities close to opencast sites

was very similar to that of children living in communities distant from such sites;

increase in particulate concentration close to the opencast sites was mainly due

to earth moving and excavation.

Monitoring

Predicting the level of dust emission is extremely difficult because of the complex

nature of mineral operations and the variable dispersion and dilution characteristics of

dust in the air. Heavy reliance is made on minimizing dust production through "good

practice" and monitoring actual dust emissions. This clearly presents problems for

development approval.

In order to fully describe background dust levels and site dust deposition

patterns, long-term and detailed dust monitoring would be required. Patterns of airborne

dust are extremely variable. In particular, dust patterns are often characterized by few or

occasional short-lived dusting events comprising high levels of dust deposition largely

caused by particular, and possibly infrequent, combinations of wind and rainfall

conditions. At other times dust deposition from the mineral site itself may be low or

insignificant, but a property/receptor is still likely to be subject to background and other

dust sources. As such it is often important to be able to differentiate dust from multiple

sources (and therefore a need to monitor for direction, color and possibly mineralogy)

and to correlate this with site specific meteorological data.

As monitoring is conducted for both health and nuisance purposes the

sophistication of different monitoring techniques differs greatly. The different monitoring

methods can be divided into two categories - active systems and passive systems.

Active monitoring devices are based on occupational health and safety monitoring

methods and passive systems which were developed through a broader approach to

environmental air pollution monitoring, including the nuisance aspect. The nature of the

two types of systems mean that active systems are more suited to measuring over

minutes, hours and days whereas passive systems are best suited for measuring over

days weeks and months.

Some form of quantitative or semi-quantitative measure should be made of rate

of deposition and severity of soiling. It is not sufficient simply to rely on descriptions or

frequency of complaints. Currently, operators and mineral planning authorities need to

agree to site specific schemes incorporating one or more of the techniques and

standards. For example, around a site where there are other dust sources, or where

there are multiple potential sources within a site, directional dust monitoring using, for

example, sticky pads would be highly desirable to allow the relative contributions of

multiple sources to be assessed. However, where there is a single dust source, low

levels of ambient dust, and few receptors, non-directional measurement of dust levels

might be adequate.

The aims and purpose of dust monitoring need to be clear if it is to be effective.

Consideration needs to be given to the location and number of monitoring stations, the

monitoring objective (i.e. to assess the potential for nuisance effects), the duration and

frequency of monitoring and the choice of monitoring gauge (noting that there are

various logistical problems associated with different gauges). There are a wide range of

monitoring techniques and methods in use for nuisance dust, of which the main types

are:

measurement of airborne dust concentrations, by using gauges which sample air

volumes or by using light scattering devices that measure the attenuation of light.

Such equipment is often very expensive and may not be able to deliver 360

directional information;

measurement of dust deposition using passive dust fall gauges or by examining

the progressive soiling by dust. Various methods available, the results from

which may be subjective and do not give directional data;

measurement of dust flux that is the movement of dust in air, in a given direction,

by means of directional gauges. Will give rise to directional data depending on

methodology used. The results may also be subjective if a repeatable technology

is not employed;

visual monitoring which is subjective and qualitative.

Passive Monitoring Systems

In comparison with active methods, these systems are generally low-tech, with

limited development of sophisticated dust monitoring equipment and are generally

applied in monitoring for nuisance dust. Nuisance is a subjective parameter around

which sampling and measurement can be difficult to undertake, illustrated by the lack of

standard guidelines for nuisance dust emissions.

Nuisance is generally related to the visual effects observed by receptors, such as

the soiling of surfaces over days and weeks or the short-term visual effect of clouds of

dust. Dust has been described as 'not readily definable'. The variation in duration and

effect of nuisance dust means that no single measure is most appropriate. Passive

systems focus on the soiling aspect of dust with monitoring periods of days, weeks and

months. Deposited dust is collected and measured to assess potential soiling effects.

The two adopted approaches are the determination of the quantity of dust deposited by

mass and the determination of soiling of a surface by a change in its optical properties.

These methods can provide non-directional or directional information.

Good Practice

Planning

Long before any submission of formal development plans to an appropriate

authority, a number of actions can be undertaken that will ultimately save considerable

resources allowing effective development. These include:

Environmental Impact Assessment with an early scoping exercise;

pre-discussions with relevant formal and informal bodies;

community consultation and involvement;

Environmental Management Systems.

The approaches above identify the main methodologies required for mineral

developers to approach effective development proposals. Within these methodologies,

further technical measures have been identified which will demonstrate minimal dust

impact.

Soil handling and storage:

The activity should be carried out as quickly as possible and

the storage mound surfaces should be sealed and seeded as soon

as is practicable (Photo 13). If possible, protect surfaces from

strong winds until the disturbed areas are sealed and stable.

Drilling and blasting:

Dust extraction equipment, such as filters, should always be used

on exhaust air emissions from drill rigs. It is important that this

material is collected properly and not simply allowed to fall to the

ground, where it can then be blown about

(Photo 14). If it is possible to remove any dusty material which

has collected on the blast area prior to detonation, then do so.

Otherwise, in dry conditions it may be helpful to water the blast

area first (Photo 15).

Overburden handling and storage:

The first step is to minimize the amount of rehandling

which obviously has cost benefits as well. Exposed material

should be protected from the wind by keeping it within voids or

protecting them by topographical features. Exposed surfaces

should be sprayed regularly to maintain surface moisture unless the mound surface has

formed a crust after rainfall or it has been grassed, which is often

a very effective way of controlling fugitive dust. If necessary this

can be done on steep broken slopes (Photo 16) as well as flatter

ground such as haul roads (Photo 17).

Where a dragline is in operation, a high pressure pump can

be used to dampen the material as the bucket is being dragged

through it (Photo 18). This is mainly to ensure the material is wet

when it is cast from the bucket at what may be a considerable

height above the surrounding ground.

Loading/Unloading Activities:

Dust is most easily picked up in the wind when the material

is falling through the air at points of transfer. It is therefore

important to reduce the drop heights wherever practicable. Photo

19 shows coal being stockpiled from a conveyor which has a

sleeve attached to it to prevent the wind picking up dust as the

material falls. In addition it may be necessary to protect the

activities from wind by erecting a screen or using a natural barrier such as the high wall

of a site.

Fine spray or fog suppression (Photos 20 & 21) can also be used in loading bays

which are exposed to the wind and therefore a likely source of dust.

Minerals processing:

The solutions to any dust problem will vary depending on the type of equipment

used but generally complete enclosure is best with use of air extraction and filter

equipment as appropriate. Water sprays can also be used.

Material storage:

A number of measures can be taken here. Material can be dampened, perhaps

with a fine spray (Photo 22); it can be covered over in some way to

protect it from the wind; or it can be screened to remove dusty

fractions prior to external storage.

Transport by conveyor within site:

Where conveyors are used, either as the major transfer system or simply as part

of the processing, the transfer points should be sheltered from the wind. Indeed, it may

be necessary to protect the entire conveyor by partially or completely enclosing it (Photo

23). Once again, drop heights should be minimized and water sprays (Photo 24) can be

beneficial.

Transport by vehicle within and off-site:

Use paved roads where practicable and where this is not possible make sure that

unsurfaced and paved road are dampened when there is the danger of dust being

generated. This can be done using water sprays from fixed pipes (Photo 25), water

guns or by using a water bowser (Photo 26). Where surfaced or paved roads are used,

they should be swept and washed regularly (Photo 27).

Vehicle speed should be restricted as there is a direct relationship between the

speed and the amount of material that is thrown up in the air. The section on traffic

states that all lorries leaving site should be properly sheeted (Photo 28) to prevent dust

escaping onto the public highways. However, it may also be advantageous to sheet

vehicles being used for internal transfer of dusty materials. Material should be loaded

and unloaded in areas protected from the wind and drop heights should be minimized.

III. NOISE POLLUTION

Definition

Sound can simply be considered as any variation in air pressure that is detected

by the human ear. The simplest definition of noise is "unwanted sound".  

Sound is an inevitable consequence of the working of minerals, although whether

this becomes environmental noise depends on whether it impinges on people outside

the site. In most cases, there will be a need to remove soil and overburden to expose

the mineral. The mineral will need to be excavated and then transported from the quarry

face to a processing area. The mineral will then be transported from the quarry site for

further processing or direct use. These activities involve the use of powered machinery

for excavation and transport of materials within the site. Processing plant on site can

often include the use of crushing and grading plant, prior to the mineral being

transported off site by road or rail vehicles. On some sites, there will also be noise

generated from the blasting of rock.

Noise is generally one of the main concerns addressed in the planning

documentation for a proposed new or extended mine or quarry. Operators will be

required to provide information on existing ambient noise levels, predicted noise levels

at different stages of the working of the mine or quarry, and details of noise mitigation

measures.

Units of Measurement

There are a number of excellent web sites which give good descriptions of the

key parameters in noise monitoring. The descriptions which follow are designed to

provide the non-expert with a basic understanding of the terms and measures involved.

Decibels (dB)

Sound has two characteristics which are amplitude and frequency. The amplitude

is the amount of pressure exerted by the air and is usually measured in Pascal’s (Pa).

Table 1 shows that the values of cover a vast range, and so they are usually

converted into decibels (dB) which is a logarithmic scale. The table gives Pa and dB

values for a number of different activities.

Noise

Sound pressure and level

Sound pressure

(Pa)

Sound level

(dB)Example

200,000,000 140 threshold of pain

130 riveting on steel plate

20,000,000 120 pneumatic drill

110 loud car horn at 1m

2,000,000 100 alarm clock at 1m

90 inside underground train

200,000 80 inside bus

70 street-corner traffic

20,000 60 conversational speech

50 business office

2000 40 living room

30 bedroom at night

200 20 broadcasting studio

10 normal breathing

20 0 threshold of hearing

Frequency refers to how quickly the air vibrates and is measured in Hertz (Hz). It

is subjectively felt as the pitch of the sound. Broadly, the lowest frequency audible to

humans is 18Hz and the highest is 18,000Hz

Measuring noise

Noise emissions are measured using sound-level meters, which detect and

record changes in sound pressure. Integrating meters also perform statistical analysis

and descriptors of interest can be determined directly from the meter.  

Noise from any particular source is reflected by any facade that directly faces

that source. Thus a microphone 1-2m in front of a building would typically yield a level

3dB higher than a free-field measurement (i.e. at least 3.5m away from a facade).  

Background noise levels can be established by continuous monitoring over a

period sufficient to provide a representative picture of the noise environment or by

averaging results from short sampling periods.

Potential Effects

Preparatory work

The initial source of noise on a new mine or quarry is the preparatory works for

the site. This will normally entail the provision of a road access, site offices and

compound, and usually some mineral processing facilities. On some of the larger sites,

there may be the construction of a rail access and sidings and/or the diversion of an

existing road or river. Most of these activities are similar to the activities carried out for

other large scale developments, and usually last for a limited duration.  

Soil stripping

The next activity is the exposure of the mineral for extraction. This will involve the

removal of soils and sometimes the removal of overburden. Soils and other soft

materials are sometimes removed by scrapers (Photo 2), large items of plant that are

either self powered (usually assisted by dozers in the scraping stage – (Photo3) or

towed by dozers (Photo 4). These machines literally scrape up the soils and move them

to another area to be deposited. This enables the soils to be stored and reused in

future. Another common method is by hydraulic excavators and dump trucks.

Noise is an inevitable consequence of the working of minerals. The extraction

process for any material will contain a number of noise generating processes. In most

cases, there will be a need to remove soil and overburden to expose the mineral. The

mineral will need to be excavated and then transported from the quarry face to a

processing area. The mineral will then be transported from the quarry site for further

processing or direct use. These activities involve the use of powered machinery for

excavation and transport of materials within the site. Processing plant on site can often

include the use of crushing and grading plant, prior to the mineral being transported off

site by road or rail vehicles. On some sites, there will also be noise generated from the

blasting of rock.  

In most cases, advantage is taken of the removal of the soils to

provide baffle mounds (Photo 5). These are soil storage mounds

that are generally located on the boundary of the site. The baffle

mounds will often provide visual and acoustic screening of the activities taking place on

site. As these activities will be taking place on the boundary of the site, the noise levels

generated by the formation and removal will be the highest experienced during the life

of the site. The highest levels will generally only occur for a matter of days at each

location.  

The next stage will depend on the type of site being operated. For opencast coal

sites and some quarries, a thick layer of overburden may need to be removed before

exposing the deposit. For most quarries, the soil and overburden to be removed is likely

to be relatively thin.

Mineral Extraction

Once the mineral is exposed, it can then be extracted. Some minerals such as

sands, gravels, clays and coal can be extracted by direct use of an excavating shovel

on the mineral. Other materials such as sandstone and limestone will need to be broken

up by blasting or ripping before they can be excavated. Blasting may also occur where

overburden is too strong to be excavated directly by shovel.  

The mineral will then be removed for initial processing or direct removal off site.

Often, the mineral is loaded on to dump trucks, but sometimes field conveyors can be

used. The noise impact of this activity is that there is normally a number of large diesel

engine machines working in the extraction area of the mine or quarry, and a number of

dump trucks carrying material from the extraction area to the processing or dispatch

area. The noise will vary in level from each item of plant and will include the noise of

material being deposited into dump trucks by excavators. However, the further away

from the working area, the less noticeable individual items of plant are. The one

exception to this is sometimes audible reversing warning devices on trucks, which can

be noticeable at considerable distances and be a source of frequent complaints.

Processing

Once the mineral has been extracted and removed from the working area, there

will normally be some processing carried out on site. This may be screening the

material to separate it into different sizes. Some materials may need to be crushed to

reduce the size of individual pieces to a manageable size. Crushing plant can be noisy,

and for hard rock there is sometimes a need to use a pecker on the largest rocks (Photo

6) before loading onto the dump truck, or a hydraulic breaker at the crush feed. Some

quarry sites may have asphalt coating plants with associated dryers, heaters, mixers

and fans (Photo 7).  

Finally, the material will be ready to be transported off site. This will usually be

carried out by heavy goods vehicles, although on some larger sites, the mineral may be

transported by other means such as rail or barge.

Location

One of the main factors that has an impact on the control of noise from minerals

workings is that the mineral can only be worked where it occurs, and the extraction work

is carried out in the open air. The minerals location is fixed, and the situation is not like

developing a new factory, where there is much more choice in the location of the

premises, and the factory building can be designed to provide the necessary

attenuation. There is limited scope for reducing environmental noise levels by changing

the equipment used to extract the mineral as reducing the size of equipment will

generally mean using greater number of items of plant, or prolonging the life of the site.

Plant noise

Some progress has been made on limiting plant noise levels through EC

Directives. One of the first of these directives in 1986 covered noise from plant such as

excavators, dozers and loaders. More recently, a wider range of plant has been covered

by the EC Directive 'Noise emission in the environment by equipment for use outdoors'.

Monitoring

Prior to submitting a planning application for a minerals site, it is normal for the

operator to commission a noise survey of existing noise levels around the site. This

would quantify current noise levels at noise-sensitive properties close to the proposed

site. The resulting ambient noise should then be agreed before a noise impact

assessment is undertaken. This information is used by the operator and local authority

to identify appropriate noise limits for the site.

Good Practice

General

It has been discussed above that there are inherent problems in limiting noise

levels from minerals workings because most of the work is carried out in the open and

the mineral can only be worked where it occurs. There are however, a number of good

practices that can be adopted to minimize the noise impact of a site.

Planning Stage

Good noise control for a site is dependent on noise issues being fully assessed

and considered at the planning stage of the site. This is the stage at which there is most

scope for mitigating noise issues. Once the site is operational, it is much more difficult to

significantly change the noise generation from the site without significant cost and

timescale implications.  

Issues to be taken into account at the planning stage should include the situation

of screening mounds (Photo 13) and fences, location of processing plant and

maintenance compounds, location of pumps and any other plant operated at night, and

haul road location both on site and from the site to the public

highway. It is standard practice now that an operator will need to

submit details of predicted noise levels for the operation of the site.

Modern computerized prediction methods are capable of making accurate predictions of

future noise levels, and planning conditions are often based on the results of the

predictions.

Choice of equipment

There may occasionally be significant noise benefits that can be achieved by

choice of equipment used on a site. This may occur if a quieter method of working is

used for the site. One example of this is the use of conveyors to transport material as

compared with dump trucks. However, there are a large number of operational issues to

be balanced against noise considerations, and it is unlikely to be possible for sites

always to use the quietest working method.

In considering the impact of choice of equipment, it is important to consider that

the overall impact of the choice of equipment will mainly be relevant at the surrounding

noise-sensitive properties. These locations will experience noise from most if not all

items of equipment operating on a site. At most sites where there will be a large number

of different noise sources operational, a large reduction in noise levels for one item of

plant may not be noticed in the overall site noise. It is only generally if sites are working

at night, or there are fixed items of plant close to a noise-sensitive property, that

individual items of plant can become dominant.

One specific item of equipment that can cause complaints is the use of vehicle

reversing alarms. These are provided for safety reasons for the workforce, and need to

generate a certain level of noise to achieve this. However, there are now more options

for vehicle reversing alarms such as directional and adjustable systems, which can help

to minimize the noise impact.

Maintenance of plant

In order to ensure that noise emissions from mineral sites remain acceptable, it is

of fundamental importance that the equipment on site is well maintained. Significant

increases in noise levels from items of plant can be generated by small defects in

silencers or acoustic enclosures not being used as designed. Poor maintenance often

leads to the generation of annoying noises, e.g. squeaking bearings, unselected

exhausts, which will lead to more complaints than would be expected from the overall

increase in noise levels. A summary of the practical measures in the choice and use of

plant to reduce noise is given in the table below.

Practical measures to reduce noise from plant

Adopt a buying policy that includes consideration of noise for all new items of plant.

Avoid unnecessary revving of engines and switch off equipment when not required.

Ensure plant and vehicles are properly maintained, check silencers and bearings.

If the noise is directional, point the source away from noise-sensitive locations.

Keep internal haul routes well maintained and avoid steep gradients.

Use enclosures for noisy plant such as pumps or generators.

Use rubber linings in, for example, chutes and dumpers to reduce impact noise.

Minimize drop height of materials.

Limit the use of particularly noisy plant or vehicles.

Start up plant and vehicles sequentially rather than together.

Ensure the plant and vehicles are operated with noise control hoods closed.

Keep lorry tailgates closed where possible.

Use any appropriate acoustic treatment equipment.

Acoustic screening

Once the working method and equipment for the site have been chosen, acoustic

screening is the main method of noise control that can be implemented on the site.

Some operations, such as processing of the mineral and maintenance operations, may

be able to be carried out within buildings, but most of the operations on site can only be

screened rather than enclosed.  

Consideration of acoustic screening does need to take place at the site planning

stage. The primary method of screening operations is to use baffle mounds or noise

fences. Baffle mounds (Photo 15) use material such as soils and overburden that has to

be removed to allow access to the mineral. They are generally located on the site

boundary and are usually designed to provide screening for noise-sensitive properties.

There are sometimes practical limitations on screening all working areas, particularly on

sites on hillsides. In some situations, there may be difficulties in providing a mound on

the site boundary and a noise fence can be used (Photo 16).

SUMMARY OF GOOD PRACTICE – NOISE

Good Practice for Mineral Planning

Authorities Consider the ambient noise, planning policies and the duration of the

noise. Discuss any limits and monitoring with the local Environmental Health Officer.

Consider the need to agree or specify planning conditions relating to:

noise limits at sensitive houses, etc, for various periods of the day;

the provision of monitoring equipment;

limits on hours of operation;

noise control measures;

adherence to a code of practice.

Occasionally, planning conditions will be required for particular activities:

noise emission from plant temporarily working close to houses;

Types of plant and/or number of items in use simultaneously.

Good Practice for Operators

Discuss noise in advance and demonstrate in their application that proposed

conditions can be met. Plan ahead and make sure that:

noise is a factor in the layout, and the nature and sequence of working;

work at night near sensitive areas is avoided where possible;

screening is part of the design;

the quieter of the methods or plant available is chosen;

especial care is taken with reversing alarms;

Haul-roads are screened and without severe gradients.

Ensure that management has the will to run the site as quietly as possible.

Check the noise characteristics of plant before use and periodically thereafter; where

appropriate retro-fit noisy plant ensure good operation and maintenance.

Make no unnecessary noise and reduce noise emissions, e.g.:

minimize height which material drops from lorries or plant;

minimize distance between loading and emptying dragline buckets;

reduce clanging of dragline buckets & chains by careful operation;

use rubber linings in chutes, dumpers, trucks, transfer points;

clad plant and ensure that the cladding is kept free of holes;

start items of plant one by one, possibly behind mounds;

switch-off equipment when not in use; avoid unnecessary revving of engines;

keep noise control hoods closed when machines are in use;

keep lorry tailgates closed where possible.

As a last resort, reduce the propagation of noise, by the use of:

temporary bunds;

portable screens.

IV. DAMAGE TO BIODIVERSITY

Mineral workings represent a disturbance of the land, so there will always be an

impact on the ecology of the area. This impact must be assessed in advance and

particular notice taken of rare or endangered species in the wider context of biodiversity.

This section considers the ecological impact assessment in some depth and looks at

good practice to preserve the wildlife and habitats during the life of the site.

Biodiversity

Biodiversity relates to all life forms - mammals, birds, reptiles, amphibians, fish,

insects and other invertebrates, plants, fungi and micro-organisms. Conservation

involves both the protection and enhancement of existing resources and the creation of

new ones. Much of the effort needed for biodiversity conservation focuses on

threatened habitats and species, but ensuring the conservation of the common and

widespread is also very important.

Potential Effects

The obvious potential negative effects of mineral extraction are that habitats are

lost, together with the species that they support. They can be lost through direct

removal by excavation, or indirectly through some of the environmental impacts. For

example, dust generated during excavation, processing or storage can settle on

sensitive habitats and have an adverse effect. Changes in the water regime (surface

water or ground water) may cause some habitats to dry out or others to become

flooded. Noise may have no influence on some species, but may affect others. All of

these potential impacts should be mitigated in order to minimize the negative impact on

biodiversity.

Significance of Impacts

Given the variety of potential ecological resources and receptors and their

interdependencies, it is important that an ecological assessment highlights the wide

range of environmental change that could result in a significant ecological impact.

Having identified and characterized these predicted changes, it is then

appropriate to describe the change and the resulting impact. In particular, it is important

to indicate whether they will be:

positive or negative;

permanent or temporary (i.e. reversible);

rapid or delayed in effect;

one-off or repeated;

It is also relevant to consider whether the effects are direct or indirect. Direct

ecological impacts are changes directly attributable to a defined action such as the

physical loss of a tract of lowland heath arising from soil stripping by a shovel and truck

operation or the immediate mortality of an individual species (and/or community of

species) crushed by working material. Indirect ecological impacts are attributable to an

action but arise because of effects on an intermediary ecosystem, process or receptor.

An example of this would be the effect of a site access road on a nearby wetland

occurring as a consequence of disruption of the local hydrological regime.

Historically, impact assessments have tended to focus on negative effects.

However, local plan policies are increasingly promoting the objective of net gain for

biodiversity from development. Positive impacts must, like negative ones, be

determined in relation to the integrity of the feature. Furthermore, in order to distinguish

between positive and negative effects, it should be determined whether the change will

promote or obstruct the achievement of favorable conservation status for a natural

habitat.

The duration of an impact is also a key consideration as all mineral

developments will give rise to a combination of both short and longer-term activities that

will result in impacts that could be temporary and permanent. It is important to recognize

that temporary can also generate permanent impacts. Measuring this type of change is

not always straight forward.

Temporary loss of food and shelter due to some habitat loss can be reversed in

as little as ten years. Most birds and mammals are sufficiently mobile and adaptable to

accommodate the temporary change with no significant impact on populations.

Conversely, the permanent loss of ancient ground flora from a woodland is likely to be

irreversible.

Any description of impact should consider the likelihood of the impact occurring.

Quantifying levels of uncertainty, e.g. as a percentage, is rarely appropriate. Instead,

ecologists should seek to categorize the uncertainty of change as to whether it is of

high, medium or low certainty.

To summarize, the key issues to note when determining and describing impacts

are:

for any ecological receptor, determination of the impact of a proposal should

represent the net effect of all relevant changes, so that the overall description is a

realistic representation of the ecological impact or outcome of the proposal for

the receptor in question;

it is likely that the description of an impact and the categories that are assigned

to it will be partly, if not entirely, qualitative in their description;

from the description it should be clear whether the impact is of negative or

positive direction;

the level of certainty regarding the assessment of the level impact (including the

likely success of any proposed mitigation) should be estimated, as objectively as

possible.

Implications of Impacts

All ecological impact assessments need to include a description of the likely

significant effects of a proposal on the environment, so that these can be taken into

consideration by decision-makers determining whether to give consent to a particular

project, and if so on what conditions. However, the concept of significance remains

largely undefined. The criteria and standards used for assessing the significance of

ecological impacts are varied and the decisions necessarily subjective.

In order to assist this process, a matrix of ecological impacts has been proposed

as part of the new guidelines for ecological assessment (in press). In summary, the

matrix defines impacts as major negative, negative, neutral, positive and major positive

and then the receptor that the impact affects according to its significance level, i.e.

international, national, regional, county, district or parish.

The external implications arising from the evaluation of the significance of

ecological effects as described above are likely to fall into three main categories. These

are:

legal implications - licensing requirements, usually relating to protected

species/habitats or other regulatory instruments;

policy implications;

implications for the detailed design and implementation of the mineral

development are granted.

It is important to note that:

for protected species it is necessary to demonstrate compliance with the law;

legislation and policy will identify the levels of impact, if any, that are acceptable

for any given proposal and also what kind and scale of measures that will be

necessary in order to compensate or mitigate for these impacts;

failure to take account of the local legal and policy context will inevitably result in

the planning permission being refused.

Good Practice

If best site practice in respect of noise, dust and water is adhered to, adverse

impacts on existing wildlife and habitats should be minimized. It is inevitable that there

will be some disruption to animal populations living close by or within the operational

site. However, observations suggest that species do become accustomed to the noise

and disturbance within a mineral site and no significant impacts on reproductive

success have been noted.

This section now deals with some practical examples of measures that can be

taken to mitigate for any negative impacts, as well as opportunities for adding to or

enhancing existing habitats.

Planning Stage

Work in partnership with nature and others.

Identify potential mineral sites that, through restoration, can contribute to BAP

targets without causing significant damage to existing biodiversity.

Make this potential contribution an important criterion in site selection - strategic

environmental assessment can assist in the selection process.

Plan habitat creation based on the 'habitat network'.

Treat environmental assessment as a process that parallels and links to scheme

design.

Operating Site

Monitor sites to identify new species and habitats that appear during operation.

Wherever possible, implement working practices to accommodate these

species/habitats.

Implement working practices that reduce noise, dust and other impacts that can

indirectly affect wildlife.

Restored Site

Put in place management measures for restored sites that meet the long term

needs of biodiversity conservation.

Implement the management needed to conserve valuable habitats or to restore

degraded areas on non-operational land.

Other Activities

Consider preparing corporate statements of commitment to biodiversity.

Encourage staff to attend training courses geared to biodiversity and minerals.

Contribute to research on biodiversity.

Share you experience in habitat creation, restoration and management.

Encourage educational and recreational use of restored and non-operational

sites (where this does not cause damage).

Design around the problem

As ever, the best option is to design the site in a way which seeks to avoid

creating an impact in the first place. Ultimately, if the impact cannot be avoided, then a

decision must be made by the developer as to whether a planning application should

still be submitted. If it is and if permission is to be recommended by planning officers,

then appropriate mitigation needs to be in place to ensure the impact is minimized.

Protection of habitat

It is likely that some habitat and therefore wildlife will survive and even thrive

during the lifetime of a mineral extraction site in areas which are not excavated.

Therefore, operators should aim to ensure that wildlife is protected at all times so that it

can co-exist alongside operations wherever possible.

During most operations a small percentage of the original landform/habitat is

retained which helps by acting as a refuge. Such refuge areas will most likely require

management to retain their features of interest. This does not need to be an onerous

activity.

Maintain some space adjacent to woodland habitats especially where wildlife is

known to feed.

Leave margins around or along trees and hedges (e.g. 4m for hedges, 5m

beyond the spread of trees for hedges with trees, 10m for trees and 15m for

woodland).

Leave margins for ditches.

Ensure that at least part of a suitable habitat is always available for any rare

species.

Phase workings adjacent to woodlands and progressively work and restore sites

to give the ecosystem more chance to survive and recover naturally.

Creation of habitats

Although the creation of new habitats can readily be incorporated into the

restoration design of a site, occasionally there may be opportunities for habitats and

species populations to be enhanced during the operational life of the site. Sometimes

this may be 'accidental' such as the creation of a suitable nesting site for peregrine

falcons in a quarry face in North Yorkshire. This was not planned and obviously has

implications for the working of the site during the nesting season.

More often, new habitats can be created that are appropriate to the region in

areas of the site which are not being excavated. These can include meadows, wetlands,

ponds, etc. and of course are particularly important where they are replacing habitats

which may be destroyed by the excavation.

An example of this is the creation of new pond areas to support populations of

Great Crested Newt which are important in the area (Photo 9). If possible, these should

be established in areas which are not going to be disturbed again in the future.

Developers should try to seek them out for consultation, though they should not

assume they will be supportive of a planned relocation.

Translocation of features

There are some features such as shrubs and hedgerows which can be physically

lifted up and relocated in an area which will remain undisturbed. An example is given in

Photos 10 and 11 which show a hedgerow which has just been transplanted (Photo 10)

and the same one 6 months later (Photo 11) having successfully become established.

This is probably more important for the habitat it represents, than for the hedgerow

itself. Hedges should not be transplanted during the nesting season.

However a note of caution should be added here. There are also many failures

with translocation and the planning authority is unlikely to view a proposal as one that

will overcome fundamental concerns. Translocation must be thoroughly planned and

executed, followed by meticulous attention and effective watering. Even then the

translocated plants may simply survive rather than thrive.

Wider Impacts

Another key consideration for operators is the avoidance of adverse impacts on

neighboring habitats of value. A potential indirect impact of mineral extraction is the de-

watering due to lowering groundwater.

SUMMARY OF GOOD PRACTICE

Good Practice for Mineral Planning Authorities Consider the need to encourage

or agree or specify planning conditions relating to:

a comprehensive baseline study of the ecosystem;

safeguarding or creation habitats as part of the local Biodiversity Action Plan;

buffer zones between workings and sensitive habitats, etc.;

progressive working and restoration to ensure continuity of habitats;

providing alternative habitats for defined species;

transplanting valuable flora as a last resort.

Good Practice for Operators

Be aware of ecological issues, probably employing a consultant to carry

out a detailed baseline survey.

Be familiar with the local Biodiversity Action Plan which and seek to play a

role in achieving some of the targets through habitat creation.

Make every attempt to design around any issues which are highlighted in

the baseline study.

Be aware of the effects of drainage on nearby ponds.

Be on the lookout for early signs of distress in the ecosystem or

agriculture and be prepared to act before significant problems occur.

Take measures to protect the existing habitats such as:

maintain some space adjacent to woodland habitats especially

where wildlife is known to feed;

leave margins around or along trees and hedges (e.g. 4m for

hedges, 5m beyond the spread of trees for hedges with trees, 10m

for trees and 15m for woodland);

leave margins for ditches;

ensure that at least part of a suitable habitat is always available for

any rare species;

phase workings adjacent to woodlands and progressively work and

restore sites to give the ecosystem more chance to survive and

recover naturally.

Progressively work and restore wherever possible to minimize the risk of

permanent damage to the ecosystem and to maximize the speed at which

it will recover.

Be prepared to transplant valuable habitats and flora, but be aware of the

limitations of this.

Stop working in vicinity of nests during breeding season.

V. QUARRY WASTE

Definition

Quarry wastes are a largely unavoidable by-product of the extraction and

processing of aggregates .They are defined as wastes because no market currently

exists for them, but unlike many other wastes they are generally inert and non-

hazardous. Materials that may be classified as quarry wastes include overburden

(although this is frequently used in restoration) and interburden (material of limited value

that occurs above or between layers of economic aggregate material) and processing

wastes (non-marketable, mostly fine-grained material from screening, crushing and

other processing activities)

Quarry fines, are the inherent fraction of an aggregate passing 0.063 mm (63

microns). Many quarries also refer to their (sub-economic) fine aggregate (finer than 4

mm) as quarry fines (or quarry dust). The term is used here to denote both fine

aggregate and quarry fines (material <63 microns).

Quarry fines can be considered a mixture of coarse, medium and fine sand

material, and silt / clay (silt and clay is known collectively as filler). In general terms, the

higher the proportion of fine sand, silt and clay, the greater the environmental and social

impacts and costs of production, storage and disposal, as the material is difficult to

handle and is more prone to mobilization under the action of gravity, wind and water.

The filler content has a major impact on technical properties and on potential end use.

The filler content of quarry fines may be reduced by washing with water or by other

methods of separation to produce a clean, saleable sand product. The silt and clay

residue is usually a waste product.

Environmental Issues

Although they are generally inert and non-hazardous, the generation, treatment

and/or disposal of quarry waste and quarry fines can be a source of friction between

aggregates companies, local communities and other stakeholders. This is particularly

true if a site is producing more than originally planned or that can be properly

accommodated within the site boundary. Therefore, ensuring that the site design is

correct at the planning stage is essential.

Due to the environmental, social and economic costs associated with storing and

managing wastes, aggregates companies try to first minimize the generation of waste

and then find beneficial uses for any waste that is produced. However, at some sites

there is a net excess of waste after beneficial uses have been considered, and this must

be managed to avoid environmental and social impact. In general terms, the potential

impacts of quarry waste can be summarized as:

Visual intrusion:

Quarry waste tips and quarry fines stockpiles can be a significant visual intrusion,

mainly when waste is dumped off-site or above the skyline (especially when it is not

landscaped or vegetated). Although it is often used as a visual or noise screen, it can be

considered an eyesore.

Water:

Run-off from quarry waste tips or quarry fines stockpiles can cause erosion and

contaminate local watercourses. Suspended solids (and acid drainage) may harm

freshwater ecosystems and impact on other water users. Waste may also create

problems if dumped on flood plains where it may exacerbate flooding. Settled silt and

clay can also be washed out and displaced from settling ponds and lagoons during

storm events.

Dust:

Large quarry waste tips or quarry fines stockpiles can be a source of airborne

dust, which can be exacerbated if they are elevated above the original ground level.

Dust may also originate from air filtration units/ stacks, haulage trucks, conveyors and

transfer points.

IMPACTS

The effects of dust, suspended solids and disposal have been used to define

potential impacts on air, water quality, land quality, fauna and flora, human health and

local communities or other stakeholders. Water consumption is addressed as a

separate impact.

Air quality

Dust:

Dust can have a substantial impact on air quality. Generally the impacts diminish

as distance from the source increases and the most acute impacts are likely to occur in

enclosed spaces (for example the processing plant) or in close proximity to major

sources. Impacts resulting from air quality degradation can include those related to

health (although these are typically linked to occupational rather than environmental

exposure), visual intrusion and, most commonly, nuisance for surround communities

and businesses.

Suspended solids:

As suspended solids are by definition those particulates present in water, they

have no direct impact on air quality. However, indirect impacts on air quality may arise

via the disposal of fine material recovered from water.

Disposal:

Disposal areas are a major potential source of dust during operational activities.

The impact may extend beyond the closure of operations if steps are not taken to

address long-term dust creation and can be exacerbated by the fact that disposal areas

are elevated above the original ground level. Dried silt ponds may also be a source of

dust, unless they are capped with soil.

Water quality

Dust:

Transfer of dust from the air to surface waters can result in contamination.

Impacts generally relate to the presence of suspended solids (in addition to those

arising from water erosion). In rare cases, physical impacts may be aggravated by the

presence of chemically active minerals in the dust (e.g. limestone contains alkaline

calcium carbonate and sulfides) that can alter water chemistry and suitability for the

fauna and flora that it supports.

Suspended solids:

Suspended solids are generally inert, although there may be exceptions (the

most common being minerals that alter the water pH). Even inert solids can have a

significant impact on water, and on the fauna and flora that it supports. The presence of

suspended solids can affect water quality far beyond the site boundary; this can

seriously impair the use and increase the cost of water for other users and uses (e.g.

drinking water, industrial uses, irrigation, and fisheries, as a coolant and for recreational

purposes).

Disposal:

Disposal areas are a major potential source of suspended solids in run-off that

may ultimately report to surface waters. Disposal areas may affect the surface water

regime (e.g. by changing surface water flow paths). Quarry waste or quarry fines

disposal may also create problems if dumped in or near areas prone to flooding.

Land Quality

Dust:

Dust impacts are relatively limited in most cases. Rarely the presence of

chemically active mineral phases in the dust (e.g. sulfides occasionally present at hard

rock quarries) may alter soil chemistry and suitability for the fauna and flora that the soil

supports.

Suspended solids:

In most circumstances direct impacts from suspended solids are unlikely.

Disposal:

Temporary or permanent land sterilization may result from the use of space

within or outside the working area, some of which could otherwise be put to beneficial

use. Temporary or permanent loss of the associated fauna and flora are also likely,

although this can be mitigated by appropriate restoration of the disposal areas.

Fauna and Flora

Dust:

Coating of vegetation and contamination of soils could possibly reduce the yield

and value of agricultural products. Although generally inert, the chemical nature of the

dust will sometimes influence the severity of the impacts upon soils and vegetation.

Dust may have physical effects on plants such as abrasion of plants, shading, and

cumulative effects e.g. drought stress. The chemical effects of dust are likely to be more

important than any physical effects. Dust deposited on the ground may produce

changes in soil chemistry, which may in the longer-term result in changes in plant

chemistry, species competition and community structure.

Agricultural lime (crushed limestone) has traditionally been used to increase crop

productivity; limestone dust deposition is likely to be well below the level of agricultural

applications and effects on crops are likely to be minimal. Areas of high ecological value

or agricultural resources, such as designated nature conservation areas containing

sensitive species, intensive horticultural areas, and fruit growing areas, may be more

sensitive to dusts than other areas.

Suspended solids:

Silt can detrimentally affect fish spawning grounds, cause damage to fish gills

and impact the invertebrate species resident in watercourse sediments. Suspended

solids also reduce penetration by sunlight. Blanketing of benthic flora and changes in

bottom morphology and characteristics may occur, particularly in areas where

suspended solids tend to settle out, with associated impacts on flora and fauna.

Exposure to suspended solids may result in the death of fish, biodiversity impacts and

food chain disruption.

Disposal:

Inhibition of vegetative regeneration and impacts on biodiversity may all result

from disposal activities.

Human health

Dust:

Potential health impacts are almost exclusively linked to the presence of airborne

dusts, in particular respirable particles. Respirable particles, i.e. those that are less than

10 µm in diameter (also known as PM10), have the potential to cause effects on human

health, including effects on the respiratory and cardiovascular systems. Atmospheric

levels of PM10 are composed of three main types. Primary particulate matter (from

combustion sources, particularly road traffic); secondary particulate matter (mainly

sulfate and nitrate formed by chemical reactions in the atmosphere); and coarse

particulate matter (consisting of suspended soils and dusts, sea-salt, biological particles

and particles from construction and quarrying).

The term 'pneumoconiosis' refers to a group of lung diseases caused by the

inhalation of dusts. Most cases occur in retired workers, the majority from the coal

mining industry; other industries affected being quarrying, foundries and potteries,

where silica is the predominant cause. Repeated and prolonged (10 - 15+ years)

occupational exposure over many years to relatively high concentrations of crystalline

silica in the respirable size range can cause the lung disease silicosis and can also be

associated with lung cancer.

Suspended solids:

Waterborne fines do not pose a significant risk to human health.

Disposal:

No direct impact on human health.

Local communities and other stakeholders

Dust-related:

Local communities can potentially be affected by dust up to 1 km from the

source, although concerns about dust are most likely within 100 meters. Deposited dust

gives rise to the greatest number of complaints to quarries from local communities,

particularly for contrasting colors that are more noticeable on deposition. Settled

particles may show up particularly on clean or polished surfaces such as cars, windows

and window ledges, or surfaces that are usually expected to remain free from dust.

There may be many sources of dust that are unrelated to aggregates production,

which may not always be readily distinguishable from site dust and so may give rise to

unwarranted complaints. In these cases an operator may need to demonstrate that the

dust does not originate at their site. There may be a local perception of elevated risks to

human health from inhalation of dusts originating at quarry sites despite evidence to the

contrary. Visual and nuisance impacts, for example plumes, reduced visibility, coating

and soiling of surfaces leading to annoyance, loss of amenity and a need to clean

surfaces and materials.

Physical and / or chemical contamination and corrosion of artifacts leading to

increased cleaning and maintenance requirements and impacts on specific industrial

activities (e.g. degradation of paint or polish finishes, and the contamination of

laboratory, quality control and medical facilities). Impacts may be aggravated in some

cases by the presence of chemically active mineral phases in the dust (e.g. limestone,

and sulfides sometimes present at some hard rock quarries).

Suspended solids:

The presence of fines can cause turbidity in water; which may limit its use for

public supply, irrigation, and industrial applications. It also has an aesthetic impact.

Disposal:

Waste dumps can be a visual intrusion; particularly when waste is dumped at or near

site boundaries, or piled-up above the skyline, especially when it is not landscaped or

vegetated. Although often used as a visual or noise screen, it can be considered an

eyesore. Concerns arise about tip stability, including long-term erosion and major short-

term failures.

Water use and consumption

Excessive water abstraction from surface waters may impair essential aquatic

ecosystem functions, leading to ecosystem degradation or loss, with impacts on

associated fauna and flora. Abstraction from groundwater may locally depress the water

table, causing direct and indirect environmental impacts over an extended area.

In both cases, the availability of water to other users may be significantly reduced

(note, however, that changes in the regulation of abstraction are more likely to result in

reduced availability for quarrying operations in the future). Impacts may be aggravated

by factors such as rate and timing of abstraction.

Efforts to reduce water consumption by recovery and reuse may have significant

economic, environmental and social implications. For example, the use of settling ponds

and lagoons may sterilize otherwise useful land and bury or require the relocation of

existing fauna and flora, while local communities may have negative perceptions of

settling ponds and lagoons for environmental and aesthetic reasons. Impacts may also

extend into local surface waters during storm events if solids are washed out' of the

pond or lagoon.

Although water may be consumed on site in order to suppress dust, the most

significant use of water is in washing plants, which are designed to remove fine-grained

particles and recover a clean aggregate product from crushed rock or sand and gravel.

Water consumption and contamination are important factors behind the consideration of

waterless or water efficient fines recovery methods. The use of water efficient

technology, water recycling (for example, through the use of settling ponds or lagoons

or thickener/ filter press methods to remove contained solids) can all substantially

reduce the overall consumption of water at a site.

Minimization

The need to minimize fines is driven in part by the environmental and social

consequences of their production and the costs of dealing with increasing volumes.

While difficult to quantify in financial terms, such consequences may represent a

substantial business risk for companies, not least through damage to corporate

reputation when impacts occur. Regulatory compliance is another major driver and is

likely to remain so water and air quality are highly regulated, for example:

Government or Regulatory Authorities

development of policies to protect, enhance and preserve air, water and land

resources

enforcement of compliance with relevant regulations and laws

sustainable use of resources

protection of sensitive species

Company

increased operating efficiency and reduced production costs

improved health and safety for workers

reduced risk of breaching consents and prosecution

reduced long-term liabilities

reduced waste storage space, handling, transport and disposal costs

reduced monitoring costs

reduced administration with regard to waste disposal

improved company image in the eyes of the shareholders, employees and

community

Local communities

protection and preservation of the local environment

access to, and use of, high quality local water- and land-based amenities

uncertainty and concern regarding exposure to contaminants

Non governmental organizations / pressure groups

monitoring compliance

focus on site-specific issues

Mitigation

An operator will normally use a mixture of approaches to deal with quarry wastes;

the mix being determined by what is technically and economically feasible, taking into

account the concerns of local communities and other stakeholders and planning

obligations.

Plan for quarry waste disposal

All approaches to dealing with quarry wastes are underpinned by the careful

planning for disposal. It is essential that the operator has accurately calculated the total

waste volume (bearing in mind any capacity to avoid waste generation or find beneficial

uses) and can properly accommodate this within the site design. If the design is not

right, site development problems are likely to arise from waste disposal issues. Waste

tips should be located to minimize potential effects on the landscape and surface water

flow and quality and take into consideration potential land-use conflicts with local

communities and stakeholders.

Find beneficial uses for wastes

As noted above, quarry wastes can often be put to beneficial use around the site

and have long been used to ameliorate the impact of workings on the landscape

through the use of screening banks, backfilling, replication or simulation of natural

landforms and to prepare ground for revegetation and restoration. Soil materials should

be stored in a manner that protects their physical, chemical and biological

characteristics until they are required for restoration. Good practice should be

implemented to prevent environmental and social impacts from wastes for which no

beneficial uses exist.

Quarry waste tips must be designed, constructed, operated and maintained to

avoid instability or movement that might give rise to health and safety risks. Incidents

involving tip instability are now rare.

Ideally all waste should be kept out of sight within the workings to reduce visual

impacts and the risk of dust dispersion. Where tips cannot be hidden their height and

shape should be managed to reduce their visual impact and exposure to wind erosion.

Amenity banks are an exception.

Waste tips should be revegetated as soon as possible to prevent wind and water

erosion (and subsequent dust generation and contamination of surface waters with

suspended solids). Non-vegetated waste tips are liable to erosion and collapse. Bare

tips should be kept wet during hot dry weather to control dust generation. Surface run-

off from waste tips should be captured and treated to remove suspended solids prior to

discharge. On closure, tips should be regraded where necessary to create a stable final

landform and to prepare them for revegetation and integration with the surrounding

landscape.

REFERENCES

Quarry and Quarrying (1996). 21st Century Universal Encyclopedia (8th Ed.) (p. 30). Australia: Regency Publishing Group.

"Quarry and Quarrying." Microsoft® Student 2009 [DVD]. Redmond, WA: Microsoft Corporation, 2008.

Air Pollution (2010). Good Quarry. Retrieved March 21, 2010 from http://www.goodquarry.com/article.aspx?id=22&navid=2

Noise (2010). Good Quarry. Retrieved March 21, 2010 from http://www.goodquarry.com/article.aspx?id=26&navid=6

Ecology and Biodiversity (2010). Good Quarry. Retrieved March 21, 2010 from http://www.goodquarry.com/article.aspx?id=24&navid=4

Quarry Waste and Fines(2010). Good Quarry. Retrieved March 21, 2010 from http://www.goodquarry.com/article.aspx?id=31&navid=11