Quality assurance and quality control

The precise nature of the work undertaken by Queensland Government staff involved in water quality monitoring requires adherence to Quality Assurance (QA) and Quality Control (QC) guidelines.

Although QA/QC are more usually recognised for laboratory analysis, they are also critically important for the whole water quality monitoring process including sampling, data analysis, data interpretation and data management.

Quality Assurance: a system of documented procedures and plans established to ensure that the water monitoring program produces data of known precision and bias. This includes staff training programs, calibration processes, written procedures and record keeping. This also includes a quality control program.

Quality Control: operational activities that confirm the quality assurance methods are functional and that information collected is accurate, precise and properly recorded. Therefore, consistent QA/QC activities produce data of known quality.

Queensland protocols for water monitoring are outlined in the Queensland Monitoring and Sampling Manual 2018.

National guidance on monitoring protocols is provided in the national water quality guidelines.


Step Quality assurance Quality control

Staff are properly trained

Staff are appropriately trained in an induction and provided with field/lab procedures

Supervision of new staff

Use of specialised equipment

Calibration procedures – all water monitoring equipment is calibrated using controlled standard solutions prepared in a NATA accredited laboratory

Equipment maintenance procedures are in place

Limits placed on calibration results

Any equipment failing calibration is not used until the problem resolved

Equipment maintained as per appropriate specific manual for that equipment

Sample collection

Provide training in sampling techniques

Methods outlined in water quality sampling manual (see link below)

Controlled record worksheets with clear site locations and the appropriate samples for each location

Controlled and accurate sample labelling

Controlled use of consumables – defined bottles appropriate for samples being collected (water sampling manual – see link below)

Use of field blanks

Record keeping

Data 'double recorded' – manually on worksheets and electronically within equipment memory

Data validation – data checked by second technical officer after being entered into the database

Storage and transport

Defined methods for storage of samples (e.g. use of ice, foil and minimisation of time between collection and storage)

Fridges and freezers monitored by use of data loggers

Sample analysis

Samples analysed using defined methods (including outsourced to a NATA accredited laboratory)

Methods based on text: ’Standard Methods for the Examination of Water and Wastewater’

Use of calibration standards and laboratory blanks

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