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.
Methods
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 |
More information
- The Monitoring and Sampling Manual 2018
- For further resources on quality assurance and control visit our publications page.