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Quality Control Programs

Analytical Quality Control in water testing laboratories

Water quality test results are rendered useless without correctly calibrated analytical instruments or strict adherence to testing methodologies.

Considering the important operational decisions that are made on the basis of your water quality test results, it’s critical to have a program in place which assures the quality of the test results provided by your laboratory services provider or by your analytical instruments.

Our analytical quality control (AQC) program provides our clients considerable value by providing them with an independent third-party check of the accuracy of their laboratory. This enables them to identify and correct analytical issues that would otherwise go undetected and so safeguards them risks, such as disinfectant underdosing and overdosing at their water treatment plants.  Some of these issues have been resolved through laboratory equipment being recalibrated or removed, modifying analytical methods and additional training of analysts.

Rest assured that your test results are accurate.

So, what’s involved? AWQC provides you with AQC solutions containing analytes at known concentrations (see list of analytes below). These are provided at whatever frequency you require. The solutions prepared are randomly chosen from a series of seven different concentration ranges so that each round of AQC solutions may differ from the previous batch. All solutions are checked, verified, bottled and labelled with the name of the solution only (the concentration is not indicated). These blind solutions together with a reporting sheet and a chain of custody form are provided for you to send to your laboratory along with your routine samples.

Analytes Typical RangeUnit
Alkalinity 29 - 3200 mg/L as CaCO3
Total Chlorine Residual 0.5 - 8 mg/L
Chemical Oxygen Demand 100 - 300 mg/L
True Colour 456nm 6.4 - 48 HU
Conductivity 580 - 3300 uS/cm
Fluoride 0.6 - 0.8 mg/L
Free Chlorine Residual 0.5 - 2.5 mg/L
Ammonia 0.4 - 28 mg/L
pH 7 - 9 pH Units
Soluble Phosphorous 0.12 - 0.18 mg/L
Total Hardness 50 - 145 mg/L CaCO3
Turbidity 0.2 - 160 NTU
N & P Containing Pesticides Various ug/L
Chlorinated Pesticides Various ug/L
Trihalomethanes Various ug/L

The validity of test results is monitored by the AWQC Analytical Quality Control (AQC) Laboratory using an extensive AQC program. The AQC Laboratory is maintained as a separate unit at the AWQC, independent of the routine analytical units. External AQC programs are also provided for water and wastewater treatment laboratories in South Australia and interstate. This service can be made externally on request.

Upon receipt of the AQC solutions, you return the completed chain of custody sheet to AWQC and distribute the AQC solutions to your laboratory. Most clients will provide these together with their routine samples. The AQC Solutions are then analysed in the same way as the other routine samples. Once you receive the AQC solutions results, these can be electronically submitted to AWQC.

AWQC’s AQC laboratory carries out a comparison against the known concentrations and a report is issued advising you of the status of the results. If the difference between the measured result and the known result exceeds an acceptable level then a Code 2 “Warning” or a Code 3 “Out of Control” status is indicated. Repeat AQC solutions can also be provided for rechecking. We can tailor the reporting to your needs with Trending graphs such as those shown below issued with the reports.

The AQC Program can be as simple or as complex as you require. For example, the most simple program we offer is the Chlorine Program where depots are sent blinded Total Chlorine samples ranging in value from (0.5 mg/l to 8.0mg/L) either monthly or fortnightly and their results are coded as either a code 1 , code 2 or code 3. And the results send back within 48 hours in the form of a spreadsheet.

For water treatment plants or desalination plants the testing can be more complex and can include blinded samples for total chlorine, turbidity, pH, colour and fluoride to name just a few. More complex testing is usually sent out to our clients on a monthly or three monthly basis.

The results can either be reported as an .xls spreadsheet or as a pdf. We can tailor the reporting to your needs with Trending graphs issued with the reports.