The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Overview of assessment

Critical aspects for assessment and evidence required to demonstrate competency in this unit

The evidence required to demonstrate competency in this unit must be relevant to worksite operations and satisfy all of the requirements of the performance criteria, required skills and knowledge and the range statement of this unit and include evidence of the following:

knowledge of the requirements, procedures and instructions for implementing the gas management plan

implementation of procedures and techniques for the safe, effective and efficient implementation of the gas management plan

the identification of the relevant information and scope of the work required to meet the required outcomes

the identification of viable options and the selection of gas management plan elements that best meet the required outcomes

working with others to undertake and complete the implementation of the gas management plan

consistent successful implementation of the gas management plan

Context of and specific resources for assessment

This unit must be assessed in the context of the work environment. Where personal safety or environmental damage are limiting factors, assessment may occur in a simulated environment provided it is realistic and sufficiently rigorous to cover all aspects of workplace performance, including task skills, task management skills, contingency management skills and job role environment skills.

Assessment of this competency requires typical resources normally used in a resources and infrastructure sector environment. Selection and use of resources for particular worksites may differ due to the site circumstances.

The assessment environment should not disadvantage the participant. For example, language, literacy and numeracy demands of assessment should not be greater than those required on the job.

Customisation of assessment and delivery environment to sensitively accommodate cultural diversity.

Aboriginal people and other people from a non English speaking background may have second language issues.

Where applicable, physical resources should include equipment modified for people with disabilities. Access must be provided to appropriate learning and/or assessment support when required.

Method of assessment

This unit may be assessed in a holistic way with other units of competency. The assessment strategy for this unit must verify required knowledge and skill and practical application using more than one of the following assessment methods:

written and/or oral assessment of the candidate's required knowledge to apply in undertaking of the implementation of the gas management plan

observed, documented and/or first hand testimonial evidence of the candidate's:

implementation of appropriate requirement, procedures and techniques for the safe, effective and efficient achievement of required outcomes

identification of the relevant information and scope of the work required to meet the required outcomes

identification of viable options and the selection of gas management plan elements that best meet the required outcomes

consistent achievement of required outcomes

first hand testimonial evidence of the candidate:

working with others to undertake and complete the implementation of the gas management plan

provision of clear and timely required support and advice on the implementation of the gas management plan

Guidance information for assessment

Consult the SkillsDMC User Guide for further information on assessment including access and equity issues.

Required skills

Specific skills are required to achieve the Performance Criteria of this unit, particularly for its application in the various circumstances in which this unit may be used. This includes the ability to carry out the following, as required to implement the gas management plan:

apply legislative, organisation and site requirements and procedures for implementing the gas management plan

access, interpret and apply technical information

access and analyse gas information related to the mine including archival and historical information

interpret and apply mathematical and scientific theorems / laws related to gas

collect, collate and evaluate gas management data

conduct investigation and prepare reports

communicate effectively in the workplace

access, evaluate and apply data from monitoring systems and equipment

operate hand held monitoring equipment

implement gas management training requirements, programs, systems and procedures

apply risk management processes and techniques

Required knowledge

Specific knowledge is required to achieve the Performance Criteria of this unit, particularly for its application in the various circumstances in which this unit may be used. This includes knowledge of the following, as required to implement the gas management plan:

legislative and site requirements for gas management including air quality and quantity, maximum and minimum values, control and distribution, flammable gas limits, ventilation fans, gas monitoring, inspections and recording / reporting

the methods of mine ventilation and their applications / limitations including exhaust / force, antitropal, homotropal, flank returns, ascensional / decensional, bleeder, Z/U/Y systems and other combinations

the methods of panel gas management and their applications / limitations including homotropal and antitropal (and in conjunction with these, the use of goaf bleed or back return), auxiliary fans, coursed ventilation (narrow side / wide side), machine mounted scrubber systems, compressed air venturis and bleeders

the impact of mining techniques

the impact of mine and panel design on gas management

the impact of differing geological features and conditions on gas management including faults, dykes, intrusions and strata deformities

the impact of coal characteristics and coal seam gradients on mine gas management systems

mine gases; the types and their characteristics, sources, physiological effects and methods of detection

mine fires; the types and possible impacts on gas management

mine explosions; the types, ignition sources and possible impacts on gas management

pressure changes; causes and the impacts on gas management

heat / humidity; the sources and factors which may impact on mine gas management

mine fans; fan types, applications and limitations

gas control devices; the types, purposes, design criteria and specifications, distribution / placement criteria and limitations

de-gassing; methods of control - including brattice, auxiliary fans, compressed air venturis, sails, hurdles and bleeders

fixed gas monitoring systems types, uses and limitations

portable monitoring equipment, types, characteristics, uses and limitations

computer-based systems for mine gas analysis

Gas Management Plan development requirements and processes

techniques for determining alarms and trigger points / levels

audit and review processes and techniques

site document control requirements

emergency response and evacuation procedures

the general use and application of ventilation theory including

gas laws including Charles and Boyle

natural ventilation

Coward's Triangle

Graham's Ratio

Ellicott Diagram

gas make

Trickett's Ratio

leakage

psychrometry and heat

CO/CO2

Kirchoff's laws

geological data

the impact of differing geological features and conditions on outburst including faults, dykes, intrusions and strata deformities

methods of control of outburst

the methods of gas drainage and their applications / limitations against the mine design, mine and panel ventilation systems, systems of mining and current and future mine development

the impacts of gas drainage on dust generation during mining

impacts of intersecting and intersected holes and hole design

principles of ventilation management

mine and goaf ventilation systems

underground water management techniques

site environmental monitoring requirements

risk management procedures

inertisation techniques

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Relevant compliance documentation may include:

legislative, organisational and site requirements and procedures

manufacturer's guidelines and specifications

Australian standards

Employment and workplace relations legislation

Equal Employment Opportunity and Disability Discrimination legislation

Interpret is defined as: the understanding needed by the person within their job role.

Gas Management Plans establish procedures for maintaining a safe environment may include:

hazard identification and quantification

risk assessment

authority and responsibility

controls established to manage identified risks

reporting and communication

document control

audit and review

And may include procedures for:

mine atmosphere monitoring

ventilation systems and usage

inertisation techniques

mine plan

trigger action response plans

emergency procedures

training and education

Gas management training applies to:

mine workers

tradespeople

permanent employees

contractors

mine officials

other special requirements

Gas management procedures may include those for:

construction

action response

permit to work/mine

condition monitoring

auditing

maintenance

atmosphere monitoring

ventilation system control

communication systems

survey procedures

sealing procedures

changes

training and recording/reporting

Hazard is defined as: a source of potential harm or a situation with a potential to cause loss (definition from AS/NZS 4360:1999 Risk Management).

Hazards may include:

irrespirable atmosphere

noxious atmosphere

flammable or explosive mixtures

outburst

Mine Atmosphere refers to the atmosphere in all areas in the general mine ventilation district and beyond into waste working and goafs / gobs in the mine.

Action (alarm or trigger) level is a generic term used to describe a level determined at the mine site at which pre-determined action is initiated or a response made.

Audit is defined as: a systematic examination against defined criteria to determine whether activities and related results conform to planned arrangement, and whether these arrangements are implemented effectively and are suitable to achieve the organisation's policy and objectives (AS/NZS 4804: 2001).

Risk is defined as: the chance of something happening that will have an impact upon objectives. It is measured in terms of consequences and likelihood (definition from AS/NZS 4360:1999 Risk Management).

Principles of mine design may include:

recovery

reserve optimisation

mining direction

geological structures

ventilation

strata control

mining method

productivity

environmental considerations

access

Standard operating procedures (SOP) are also known as safe working procedures, safe operating procedures and standard working procedures.

Mine gases may include:

seam gases

methane

carbon dioxide

oxides of nitrogen

hydrogen

carbon monoxide

sulphur dioxide

hydrogen sulphide

hydrocarbons

contaminations

normal atmosphere gases

Gas make characteristics may include:

gas content

gas pressure

absorption

desorption

hydrostatic pressure

strata moisture content

permeability and porosity

tectonic stress

Gas make characteristics may include:

stoppings

overcasts

regulators

preparation seals

ventilation doors

bulk heads

goaf seals

final seals

pressure chambers

air locks

Explosion control devices may include:

water barriers

stone dust barriers

trickle dusters

calcium chloride

stone dust

triggered barriers

Gas management devices and methods may include:

gas drainage

infusion

scrubbers

automatic gas detectors

tube bundle systems

de-gassing device on auxiliary fans

gas monitoring systems

Geological conditions may include:

faults

dykes

intrusions and strata deformities

existing or induced stress or strain

depth of overlaying strata

adjacent coal seams

Coal seam characteristics may include inherent factors such as:

rank

petrology

moisture

particle size

seam gas - composition and content

pyrites

permeability

Or depositional factors such as:

seam thickness

multiple and rider seams

seam dip

depth of cover

cleats

friability

Geological and physical conditions of the seam and surrounding strata which may contribute to outburst potential may include:

cutters

changing cleat

coal colour

Mine atmosphere monitoring may include:

continuous monitoring

portable (hand held) monitoring

collection of bag samples

gas chromatography

ventilation measurements from all area of the mine including sealed areas

waste workings

Infrastructure may include:

pipes

valves

hoses

pumps

drainage plant

flame arresters

power supply to bore holes

cleaning equipment

Types of fires may include:

solid

liquid

gas

Ignition sources may include:

electrical

static discharge

friction

contraband

spontaneous combustion

naked flame

chemical

explosives

Disruptions / ventilation pressure changes may include those resulting from:

planned disruptions

changes in barometric pressure

fall of ground causing blockage and/or overpressure causing damage

fan changes/failure

ventilation control device changes/failure

outburst

holing into previous workings

re-circulation

ventilation circuit changes

natural ventilation pressure changes

explosions

changes in ambient temperature/humidity

fires

equipment movement

flooding of roadways

application of inertisation

Effect of re-circulation may include:

build up of contaminant concentration (gas, fumes, dust, heat)

decrease in oxygen

Criteria for safe mine ventilation may include:

statutory and regulatory requirements

mine ventilation management plan

measures to reduce and/or control seam gas

introduced gas

fumes and dust

temperature/humidity and maximum/minimum velocity specification

ventilation efficiency

Monitoring devices may include:

barograph

tube bundle

real time telemetry

portable (hand held) monitoring

bag samples

gas chromatography

Monitoring includes that related to:

atmospheric pressures

ventilation pressures and quantities

gas quality and quantity

gas composition

temperature

fire

the condition monitoring of ventilation devices

Methods of ventilation may include:

exhaust/forcing

anistropal (antitropal)

homotropal

flank returns

ascentional/descensional

bleeder

Z/U/Y systems

overlapping systems

other combinations

Alarm systems and action plans may include those for:

gas concentration/make/ratios

spontaneous combustion (physical and gaseous)

combustion indicators

condition monitoring for fans (vibration/temperature/current/failures)

ventilation devices

monitoring hardware

gas content of the coal seam

Maintenance of the ventilation system may include:

inspection

servicing

repair