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Title / Operate pH and alkalinity control processes in water treatment
Level / 4 / Credits / 8
Purpose / People credited with this unit standard are able to: monitor and adjust pH and alkalinity control process inputs; carry out preventive maintenance procedures and repairs on pH and alkalinity control equipment; and describe the storage, handling, and preparation of chemicals, and chemical dosing systems used in pH and alkalinity control processes, in water treatment.
Classification / Water Industry > Water Treatment
Available grade / Achieved
Explanatory notes
1Reference
Legislation relevant to this unit standard includes but is not limited to the Health and Safety in Employment Act 1992, and Hazardous Substances and New Organisms (HSNO) Act 1996.
2Definition
Organisational procedures – instructions to staff and procedures which are documented in memo or manual format and are available in the workplace. These procedures include but are not limited to – site specific procedures, laboratory procedures, manufacturers’ specifications, product quality specifications and reference to legislative or regulatory procedures relevant to the industry.
3A person is required to have approved handler certification if handling substances being transferred under the HSNO Act 1996. Information on approved handler procedures can be obtained from
Outcomes and evidence requirements
Outcome 1
Monitor and adjust pH and alkalinity control process inputs in water treatment.
Rangeprocess inputs include but are not limited to – chemical dose rate; slurry or solution strength.
Evidence requirements
1.1Testing equipment is calibrated, if required, tests or measurements for monitoring process inputs are carried out, and results are recorded, in accordance with consumer demand, compliance procedures, and organisational procedures.
1.2Process inputs are adjusted in accordance with results of testing.
1.3Process history is analysed, trends are identified, and process control is adjusted in accordance with organisational procedures.
1.4Process inputs are adjusted in response to process failure in accordance with organisational procedures.
1.5Consumables are checked and ordered in accordance with organisational procedures.
Rangechemicals, power, instruments.
Outcome 2
Carry out preventive maintenance procedures on pH and alkalinity control equipment in water treatment.
Evidence requirements
2.1Preventive maintenance procedures are carried out in accordance with organisational procedures.
2.2Procedures for maintaining process continuity are carried out in accordance with organisational procedures.
2.3Personal protective equipment is used while carrying out preventive maintenance in accordance with health and safety procedures.
Outcome 3
Carry out repairs on pH and alkalinity control equipment in water treatment.
Evidence requirements
3.1Repairs are carried out according to process and/or equipment failure in accordance with organisational procedures.
3.2Personal protective equipment is used while carrying out repairs in accordance with health and safety procedures.
Outcome 4
Describe the storage, handling, and preparation of chemicals, and chemical dosing systems used in pH and alkalinity control processes in water treatment.
Evidence requirements
4.1The storage, handling, and preparation of chemicals used in pH and alkalinity control are described in terms of the HSNO Act 1996.
4.2Chemical dosing systems used in pH and alkalinity control are described in terms of the components, methods, and points of application.
Rangecomponents – chemical pipework, dosing pumps, speed control, stroke control, flow rate, tank of dilutant, instrumentation for automatic control.
Replacement information / This unit standard and unit standard 24964 were replaced by unit standard 29990.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 / 19 September 2008 / 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 2019 / / New Zealand Qualifications Aut