This unit describes the skills and knowledge required to construct multiple aquifer production bores. It includes designing, constructing and developing multiple aquifer bores, disinfecting bores and equipment and decommissioning bores.

It applies to those working in operational roles. They generally perform tasks involving a broad range of skilled applications in a wide variety of contexts, which may involve some discretion and judgement in selecting equipment, services and contingency measures.

Licensing, legislative and certification requirements that may apply to this unit can vary between states, territories, and industry sectors and must be sourced from relevant jurisdictions prior to applying this unit.

The candidate must demonstrate the ability to complete the tasks outlined in the elements, performance criteria and foundation skills of this unit, including evidence of the ability to:

construct multiple aquifer production bores on at least three occasions, including:

planning and preparing for constructing multiple aquifer bores, including:

selecting a bore site to prevent contamination and minimise interference with other bores

selecting appropriate drilling method for planned geology in a multiple aquifer system (potential drilling methods include rotary air, rotary mud, sonic, cable tool and auger)

designing a multiple aquifer bore to ensure the exclusion of unsuitable waters and to prevent the inter-mixing of aquifers with different water quality or Standing Water Levels

constructing and developing multiple aquifer bores in line with established requirements, including:

drilling and isolating target production zone

identifying and logging strata encountered during drilling including aquifer and aquitard (confining layer) units

confirming or amending bore design based on testing and encountered geology, using:

sieve testing

lithological logging

geophysics testing

aquifer yields testing

water quality testing

selecting likely water entry mechanism from the formation to the bore including stainless steel screens, filter packs, slotted casing and open-hole

calculating and making up cement grout volumes and mixing grout component quantities, including:

cement powder

water

bentonite

other additives as required

calculating hole and annular volumes

calculating grout specific gravity

determining appropriate screen and filter pack configuration, accounting for:

formation grain size

screen aperture

annular space

filter pack mineralogy, including quartz sand

natural filter pack potential (formation)

constructing bore according to confirmed or amended design, including:

assembling and installing casings, seals and screens

installing filter pack

grouting

sealing intermediate and/or production casing strings or seal selected zones to complete grouting operations

continuing development until a continuous, clean supply of water is obtained

estimating yield by using methodologies of:

air lifting

pumping

disinfecting/decontaminating bore and drilling equipment in line with established requirements, including:

disinfecting bores and installed equipment using proprietary chemical solution

decommissioning bore holes in line with established requirements, including:

decommissioning failed or unwanted bores as required.

During the above, the candidate must:

locate and apply required documentation, standards, policies and procedures

select and wear personal protective equipment required for work activities

maintain plumbness and alignment of the hole within limitations

use a range of communication techniques and equipment essential to the safe completion of work activity, including hand, audible and other signals

meet written and verbal reporting requirements and procedures associated with equipment operations.

The candidate must be able to demonstrate knowledge to complete the tasks outlined in the elements, performance criteria and foundation skills of this unit, including knowledge of:

key legislation required to construct multiple aquifer production bores

key policies, procedures and established requirements for constructing multiple aquifer bores, including those for:

Minimum Construction Requirements (MCR)

workplace health and safety

environmental practice

accidents and emergencies

safety data sheets (SDS)

housekeeping

key factors affecting multiple aquifer bore performance, including:

properties, uses and effects of and differences between:

single and multiple aquifers

drilling fluids

casings

cement (grout) additives

grout placement methods and procedures

hole preparation for cementing (grouting) operations

pressure cementing methods

results of sieve analysis

calculations for:

up hole velocity

specific gravity

cement mixes

screen design parameters

flow rates (including L/sec and GPM)

conversion from imperial to metric and vice versa

equipment processes, technical capability and limitations

casing strength and collapse characteristics

applications for wire-wound screens

screen design parameters to ensure appropriate entrance velocities

types of pathogens and contaminants including bacteria.

Mandatory conditions for assessment of this unit are stipulated below. The assessment must:

include access to:

bore site(s)

drilling rig and equipment

water supply

cement grout (cement, water and bentonite)

casings, seals and screens

filter pack material

personal protective equipment

air compressor or pumping equipment

potable supply disinfectant

personal protective equipment

be conducted in a safe environment

be assessed in context of the sector's work environment

be assessed in compliance with relevant legislation and regulations and using policies, procedures, processes and operational manuals directly related to the industry sector for which it is being assessed

confirm consistent performance can be applied in a range of relevant workplace circumstances.

Where personal safety or environmental damage are limiting factors, assessment may occur in a simulated work environment* provided it is realistic and sufficiently rigorous to cover all aspects of this sector’s workplace performance, including environment, task skills, task management skills, contingency management skills and job role environment skills.

Assessor requirements

Assessors must be able to clearly demonstrate current and relevant industry knowledge and experience to satisfy the mandatory regulatory standards as set out in the Standards for Registered Training Organisations (RTOs) 2015/AQTF mandatory requirements for assessors current at the time of assessment and any relevant licensing and certification requirements. This includes:

vocational competencies at least to the level being delivered and assessed

current industry skills directly relevant to the training and assessment being provided

current knowledge and skills in vocational training and learning that informs their training and assessment

formal relevant qualifications in training and assessment

having knowledge of and/or experience using the latest techniques and processes

possessing the required level of RII training product knowledge

having an understanding and knowledge of legislation and regulations relevant to the industry and to employment and workplaces

demonstrating the performance evidence, and knowledge evidence outlined in this unit of competency, and

the minimum years of current** work experience after competency has been obtained as specified below in an industry sector relevant to the outcomes of the unit.

It is also acceptable for the appropriately qualified assessor to work with an industry expert to conduct assessment together and for the industry expert to be involved in the assessment judgement. The industry expert must have current industry skills directly relevant to the training and assessment being provided. This means the industry subject matter expert must demonstrate skills and knowledge from the minimum years of current work experience after competency has been obtained as specified below, including time spent in roles related to the unit being assessed:

*Guidance on simulated environments has been stipulated in the RII implementation guide located on VETNet.

**Assessors can demonstrate current work experience through employment within industry in a role relevant to the outcomes of the unit; or, for external assessors this can be demonstrated through exposure to industry by conducting a minimum number of site assessments as determined by the relevant industry sector, across various locations.

*** While a Unit of competency does not have an AQF level, where a unit is being delivered outside of a qualification the first numeric character in the unit code should be considered as the AQF indicator level for assessment purposes.

This section describes those language, literacy and numeracy and employment skills that are essential to performance.

Drilling