NZQA Expiring unit standard
24920 version 2
Page 1 of 5
Title
Excavate and lay pipes, and reinstate trench for water reticulation
Level
3
Purpose
Credits
16
People credited with this unit standard are able to: set out a
pipe route using control points according to the specifications
and organisational procedures; assess the requirements of the
job, and order resources; undertake open cut excavation in
preparation for pipe installation, backfill, assess and implement
dewatering, and assess and notify trench stability; check and
form trench depth, grade and base in preparation for pipe
installation; transport and store pipes, install bedding and pipe,
and compact backfill; test the completed pipeline section; and
reinstate trench surface according to specification.
This unit standard is for people who work on water, or
wastewater, or stormwater reticulation systems, which
collectively make up water reticulation services.
Classification
Water Industry > Water Reticulation
Available grade
Achieved
Explanatory notes
1
References
Legislation relevant to this unit standard includes but is not limited to the Health and
Safety in Employment Act 1992, and Resource Management Act 1991.
Approved Code of Practice for Excavation and Shafts for Foundations, published by
Occupational Safety and Health Service, Department of Labour,
http://www.osh.govt.nz.
2
Definitions
Specification – the drawings and specification setting out the position and standards
of the proposed work.
Organisational procedures – instructions to staff, and procedures which are
documented in memo or manual format and are available in the workplace. These
requirements include but are not limited to – site specific requirements,
manufacturers’ specifications, product quality specifications, and legislative or
regulatory requirements.
3
Assessment
The pipeline must be at least 25mm in diameter, and at least 10 metres in length.
The pipeline may be a gravity pipeline or a pressure pipeline, and be part of a
reticulation system. Pipe materials must be those accepted by the owner of the
reticulation system.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
24920 version 2
Page 2 of 5
Outcomes and evidence requirements
Outcome 1
Set out a pipe route using control points according to specifications and organisational
procedures.
Evidence requirements
1.1
The route of the pipeline is checked for availability in terms of other services
and surface use.
Range
1.2
all underground services, traffic use, surface cover options.
The route of the pipeline is set out using centre line or offset marks in terms of
position.
Outcome 2
Assess the requirements of the job, and order resources.
Range
situations – routine, emergency.
Evidence requirements
2.1
The resource and documentation requirements of the job are assessed in
accordance with organisational procedures.
Range
resources include but are not limited to – materials, staff, plant;
documentation includes but is not limited to – road opening notice.
2.2
Resources are sourced and obtained in accordance with organisational
procedures.
2.3
The opportunities for contamination during new pipeline construction are
described in terms of water quality risks, and methods to reduce these risks.
Range
includes but is not limited to – pipe storage, site cleanliness,
hygiene facilities, trench inundation, pipe plugs, flushing,
disinfection.
Outcome 3
Undertake open cut excavation in preparation for pipe installation, backfill, assess and
implement dewatering, and assess and notify trench stability.
Evidence requirements
3.1
Excavation is carried out on line, and in accordance with grade and
organisational procedures.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
24920 version 2
Page 3 of 5
3.2
Excavation avoids interference with other services and organisational
procedures.
3.3
Excavated material is assessed for suitability for backfill, and suitable material
ordered in accordance with organisational procedures.
3.4
Site is assessed for dewatering, and dewatering is implemented, in accordance
with organisational procedures.
3.5
Trench stability is assessed, and requirements for trench support are identified,
in accordance with organisational procedures.
Outcome 4
Check and form trench depth, grade and base in preparation for pipe installation.
Evidence requirements
4.1
The trench depth is checked according to specifications and site constraints.
4.2
The trench sub-grade is checked for soft spots in accordance with the
specification and organisational procedures.
Range
4.3
one of – visual, penetrometer tests.
Any soft spots in the trench sub-grade are assessed and corrected in
accordance with organisational procedures.
Outcome 5
Transport and store pipes, install bedding and pipe, and compact backfill.
Evidence requirements
5.1
Pipes are transported and stored in accordance with manufacturer’s
instructions.
5.2
Bedding is placed in the trench, and compacted in accordance with the plan and
specification.
5.3
Pipes are lifted, and placed into the trench in accordance with manufacturer’s
instructions.
5.4
Pipe bends, fittings, joints, and anchoring are installed according to
specification.
5.5
Pipes are surrounded with compacted bedding material in accordance with the
specification.
5.6
Backfilling is compacted in layers according to specification.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
24920 version 2
Page 4 of 5
Outcome 6
Test the completed pipeline section.
Evidence requirements
6.1
The pipeline is tested in accordance with the specification.
may include but is not limited to – low pressure air tests, water
tests, high pressure water tests;
evidence is required for at least one.
Range
Outcome 7
Reinstate trench surface.
Range
may include but is not limited to – grass verge, chipseal, concrete, asphalt;
evidence is required for at least one.
Evidence requirements
7.1
Trench surface is reinstated according to specification.
Replacement information
This unit standard replaced unit standard 19203.
This unit standard is expiring. Assessment against the standard must take place by
the last date for assessment set out below.
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
19 September 2008
31 December 2016
Review
2
21 July 2011
31 December 2016
Consent and Moderation Requirements (CMR) reference
0179
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA,
before they can report credits from assessment against unit standards or deliver courses
of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
24920 version 2
Page 5 of 5
Requirements for consent to assess and an outline of the moderation system that applies
to this standard are outlined in the Consent and Moderation Requirements (CMR). The
CMR also includes useful information about special requirements for organisations wishing
to develop education and training programmes, such as minimum qualifications for tutors
and assessors, and special resource requirements.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016