When gathering data for a Phase II ESA or other report through on-site testing or environmental site screening, it is important to note that the results are only as good as the data. Inaccurate data means that decisions will be based on erroneous beliefs and a poor site understanding. By ensuring that the data is precise and accurate, and that it has been gathered in an appropriate manner, the investigative team gains confidence that their data is, in fact, accurate to the site’s conditions.
AEL has carefully developed methods to assure quality in all areas of site work, data analysis, and reporting. In the field, sampling procedures are carried out in a method that avoids cross-contamination and ensures samples are labeled with unique barcodes to preserve sample identity.
The goal of QA/QC for use with on-site testing is to ensure that the sampling results are accurate to the true condition of the soil. The following methods are key to building confidence and assurance in the site results.
Sampling Unit Accuracy
Calibration of the field instrument to a known standard is critical in ensuring that the equipment is operating within acceptable ranges. By repeating this process several times daily during the project the reliable, representative data can be collected.
Well developed sample procurement and handling methods ensure soil, groundwater and soil vapour samples are representative of site conditions. These methods include:
- reducing the potential for cross contamination through decontamination of sampling equipment or single use samplers like geoprobe sample tubes;
- using unique sample barcode identifications [which follows tracks samples through sampling, analysis and reporting] to avoid data transposition errors or duplicate reference numbers;
- ensuring proper sample preservation, storage and hold times are adhered to, and;
- providing appropriate field duplicates and blanks are required by regulation and/or applicable site investigation standards. These include field blanks and duplicates for analysis.
Certified Laboratory Analysis
Samples are submitted to a CALA-accredited laboratory (or other appropriate certification) which ensures applicable standards are followed including method blank, laboratory control sampling, matrix spikes, sample duplicates, and other appropriate testing to ensure that quality standards are maintained.
Avoiding Transcription Error
AEL takes a simple approach to avoiding transcription error, which is a common source of loss of data quality. By minimizing the use of transcription entirely, AEL ensures that data is not incorrectly transcribed. This is done by importing data directly from the on-site testing unit into a spreadsheet where it is interpreted, with each sample identified with its unique barcode label.
Data from the laboratory is imported in an automated way as well, and is checked for quality upon import.
By ensuring that the data being used for on-site screening is reliable, AEL’s environmental consulting team provides clients with the information they need to make confident decisions about their site.