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 establishing and maintaining the gas drainage management plan

implementation of procedures and techniques for the safe, effective and efficient establishment and maintenance of the gas drainage 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 drainage techniques that best meet the required outcomes

working with others to undertake and complete the establishment and maintenance of the gas drainage management plan

consistent successful establishment and maintenance of the gas drainage 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 establishment and maintenance of the gas drainage 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 drainage techniques that best meet the required outcomes

consistent achievement of required outcomes

first hand testimonial evidence of the candidate's:

working with others to undertake and complete the establishment and maintenance of the gas drainage management plan

provision of clear and timely required support and advice on the establishment and maintenance of the gas drainage 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 establish and maintain the gas drainage management plan:

apply legislative, organisation and site requirements and procedures for establishing and maintaining the gas drainage management plan

access, interpret and apply technical information

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

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

access, interpret and apply geological reports

perform gas drainage planning mathematical calculations

access, evaluate and apply design criteria for gas drainage systems and devices

interpret computer spreadsheets and modelling / simulations

collect, collate and evaluate gas drainage data

establish technical procedures relating to gas drainage

conduct enquiries/investigations and prepare reports

access, evaluate and apply data from monitoring systems and equipment

operate hand held monitoring equipment

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 establish and maintain the gas drainage management system:

legislative and site requirements which may include those for gas drainage drilling, gas drainage installation and recovery, ventilation requirements, return airways gas levels, intake airway gas accumulated levels, gas control and distribution, environmental management, local government requirements, inspections and reporting

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 impact of gas drainage on mining techniques, mine and panel design and production output

the impact of the strata geology and coal seam characteristics on the gas drainage management plan, including coal seam gradient, moisture content, friability, permeability, gas content, gas composition, the porous features of the coal seam, stresses and intrusions

outburst mining monitoring procedures

drilling options and related equipment and techniques, including directional drilling techniques

hazard management processes and techniques

content, composition and pressure

the effects of the gas in the coal seam

the effects of gas characteristics from roof

the impacts of accumulation of coal dust after gas drainage has been completed

pressure changes; causes, the impacts on the ventilation system, and the effects on gas drainage

heat/humidity; the sources and factors which may impact on gas drainage and personnel

mine fans; fan laws, fan types, performance characteristics, configurations, applications and limitations in association with the gas drainage management plan

ventilation control devices; the types, purposes, design criteria and specifications, distribution / placement criteria and limitations in association with the gas drainage management plan

ventilation 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, sales, hurdles, bleeders and purging

fixed gas drainage monitoring systems types, characteristics, uses and limitations

portable monitoring equipment for gas drainage purposes, types, characteristics, uses and limitations

functions, capabilities, advantages, limitations and uses of gas drainage computer modelling and simulation techniques

use of computer-based systems for mine environment and gas drainage analysis

gas drainage management plan development requirements and processes

gas drainage surveys; the types, frequency and method for conducting including pressure/quantity/temperature and gas

processes and techniques for determining alarms and trigger points / levels

audit and review processes and techniques

site control documentation requirements

emergency response and evacuation procedures

general uses and applications of ventilation theory, including:

Atkinson's equation

methods of determining frictional resistance

gas laws, including Charles and Boyle

natural ventilation pressures

gas make

leakage

determination of mine resistance curves

regulator and equivalent orifice calculation

determination of fan operating / duty points

Kirchoff's laws

mine operational procedures

strata control systems and their effects on gas drainage

mine and goaf ventilation systems

underground water management principles and systems

impacts of intersecting and intersected holes and hole design

site environmental monitoring requirements

legislative and mine reporting procedures

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

Coal seam characteristics may include:

inherent factors such as rank

petrology

moisture

particle size

seam gas make

pyrites

Or depositional factors such as:

seam thickness

multi seams

seam dip

depth of cover

cleats friability

interaction of other coal seams and gas makes

clay bands within the coal seam and molorite zones

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

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

outbursts

induced outburst

gas under pressure

location of drainage pipes

static electricity

gas leakage from and into gas pipelines

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).

Action (alarm or trigger) level is a generic term used to describe a level determined at the mine site at which 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).

Gas drainage management plans establish procedures for maintaining a safe environment including:

hazard identification and quantification

risk assessment

authority and responsibility

controls established to manage identified risks

reporting and communication

document control

Gas drainage management plan may include:

procedures for gas drainage drilling program

gas or geological anomaly detection

mine atmosphere monitoring

stimulation techniques

goaf seals

reporting requirements

auditing

ventilation systems and usage

mine plan

action plan

systems of mining

response plans

emergency procedures

individual and group responsibilities

training and education procedures

Principles of mine design may include:

recovery

reserve optimisation

mining direction

geological structures

ventilation

strata control

mining method

productivity

environmental considerations and access

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

Mine gases may be seam gases or gases from introduced sources and may include but not be limited to:

methane

carbon dioxide

carbon monoxide

oxides of nitrogen

hydrogen

sulphur dioxide

hydrogen sulphide

hydrocarbons

Ventilation systems may include the use of:

main mine fan

auxiliary fans

brattice

regulators

seals

stoppings

overcasts

ventilation doors

surface drainage boreholes

pressure chambers

Geological conditions may include:

faults

dykes

intrusions

strata deformities

induced stresses

depth of overlaying strata

strength of immediate strata

under and over the coal seam

mining lease gas make

Gas make characteristics may include:

gas content

gas pressure

absorption

desorption

hydrostatic pressure

strata moisture content

permeability and porosity

tectonic stress

Gas drainage monitoring may include:

continuous monitoring

leakage monitoring (laser beam technology)

portable (hand held) monitoring

collection of bag samples

pipeflow and pressure measurements

gas chromatography

ventilation measurements from relevant areas

Gas drainage infrastructure may include:

vacuum pumps

pipes

boreholes and stand pipes

gas separators and casing

surface installations

gas drainage plant, including building

valves

hoses

water pumps

flame and lighting arresters

power supply to bore holes

cleaning equipment

air compressors

electricity and water services

pressure gauges and hydration plants

Gas management training applies to:

mine workers

tradespeople

permanent employees

contractor

mine officials

other special requirements

Alarm systems and action plans may include those for:

gas concentration/make

combustion indicators

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

ventilation devices

monitoring hardware

temperature alarms

Procedures required to support the gas drainage management plan may include those for:

construction

action response

permit to work

condition monitoring

auditing

maintenance

document control

atmosphere monitoring

ventilation system control

communication systems

survey procedures

standard operating procedures

changes

training and recording/reporting

Maintenance of the gas drainage system may include inspection, servicing and repair.