Page 1 of 4
Title / Demonstrate knowledge of, and evaluate, a small drinking-water supply
Level / 4 / Credits / 6
Purpose / People credited with this unit standard are able to, for a small drinking-water supply, demonstrate knowledge of: the factors affecting the quality and quantity of water available from water sources and catchments; water treatment processes; the components used for drinking-water reticulation from storage to taps; monitoring and recording procedures to determine the safety and quality of drinking-water; and evaluate a small drinking-water supply for improvements.
Classification / Water Industry > Drinking-Water
Available grade / Achieved
Explanatory notes
1Legislation includes but is not limited to the – Health Act 1956, Local Government Act 2002, Consumer Guarantees Act 1993, Building Act 2004, and Resource Management Act 1991.
2Definitions
Small drinking-water supply – a drinking-water supply servicing up to 500 people; and which includes catchment, source, treatment, and reticulation.
Secure ground water – water contained beneath the land surface which is abstracted via a secure well head or similarly proven structure, and has been demonstrated to show that contamination by pathogenic or harmful organisms is unlikely.
UV – ultraviolet.
3Some Marae are using traditional Māori indicators to determine water quality, for example, amount of algae and weed growth, presence of algae on rock, flow rate, and smell.
4Standard
Drinking-Water Standards for New Zealand 2005 (Revised 2008). Ministry of Health, Wellington.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of the factors affecting the quality and quantity of water available from water sources and catchments for a small drinking-water supply.
Evidence requirements
1.1Water sources and catchments are described in terms of the factors affecting quality, and the consistency of quality of water.
Rangesurface or surface-influenced water, secure ground water.
1.2Water sources and catchments are described in terms of the factors affecting availability and reliability of supply, and the need for storage.
Rangefactors include but are not limited to – less rain, more rain.
1.3Source water is described in terms of the contaminants identified in the Drinking-water Standards for New Zealand 2005.
Rangecontaminants – microbiological pathogens, blue-green algae; chemical, aesthetics, corrosion.
Outcome 2
Demonstrate knowledge of water treatment processes for a small drinking-water supply.
Evidence requirements
2.1Water treatment processes and water quality parameters are described in terms of barriers and suitability of supply.
Rangeturbidity, iron, flow rate.
2.2Settlement processes are described in terms of their effect on contaminant removal.
2.3Water treatment filtration processes are described in terms of their effect on contaminant removal, maintenance, and cost.
Rangetwo of – sand, cartridge, membrane, mechanical.
2.4Water treatment disinfection processes are described in terms of their effect on microbiological contaminants, and the dose rates required.
RangeUV; chlorine – liquid, gas, solid.
2.5Water treatment pH control processes are described in terms of their aesthetic impact, and corrosion control.
Rangeimpact on the system corrosion, ideal levels in the drinking-water system, methods for testing, methods of correcting, impact on disinfection.
2.6Water treatment processes are described in terms of their inter-relationships.
Outcome 3
Demonstrate knowledge of the components used for drinking-water reticulation from storage to taps for a small drinking-water supply.
Rangetanks, pipes, pumps, control valves, backflow preventors.
Evidence requirements
3.1Components used in reticulation are described in terms of their function.
3.2Components used in reticulation are described in terms of hygienic methods of maintenance.
Outcome 4
Demonstrate knowledge of monitoring and recording procedures to determine the safety and quality of drinking-water for a small drinking-water supply.
Evidence requirements
4.1Sampling results, and frequency of and reasons for, drinking-water monitoring are compared in accordance with the requirements of the Drinking-water Standards for New Zealand 2005.
4.2Maintenance of drinking-water monitoring records is described in accordance with Drinking-water Standards for New Zealand 2005.
Outcome 5
Evaluate a small drinking-water supply for improvements.
Rangesource and catchment, treatment, reticulation, monitoring.
Evidence requirements
5.1A small drinking-water supply is described in terms of its components.
5.2A small drinking-water supply is evaluated, and viable options for improvement are identified and described.
Replacement information / This unit standard was replaced by unit standard 29965.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 AssessmentRegistration / 1 / 20 April 2006 / 31 December 2018
Review / 2 / 16 March 2017 / 31 December 2018
Consent and Moderation Requirements (CMR) reference / 0101
This CMR can be accessed at
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.
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.
Infrastructure ITOSSB Code 101813 / New Zealand Qualifications Authority 2018 / / New Zealand Qualifications Aut