Tech Focus: Assessing Data Quality Using Data Validation

As engineers, geologists, and environmental scientists, it is in our nature to question things: Why did a particular event occur? What are the current site conditions? How are things changing?

So why shouldn’t this curiosity also apply to the analytical data used to make project decisions?

We should question whether laboratory results are “good enough” for the project’s data quality requirements. And what it means if a surrogate is recovered high, or if a holding time is exceeded, or if the field blank is contaminated.

Data validation is the process of assessing data quality in an effort to understand any potential limitations and instill confidence in the information provided. Langan’s in-house data validation team has the ability to perform the validation, while also acting as a technical resource for project teams with laboratory and chemistry questions.

At a minimum, data validation reviews sample preservation and holding times, blanks (field, trip, and laboratory), surrogates, laboratory control samples (aka blank spikes), matrix spike/matrix spike duplicates, laboratory duplicates, and field duplicates. A more thorough validation may also review instrument calibration, chromatographic patterns, and recalculation of results from raw data. While deliverables are prepared per regulatory agency requirements, the results of data validation extend much further than checking off a list of requirements. Improper or inaccurate data validation can result in rejection of the data from the regulatory agency and, in extreme cases, litigation.

Throughout the validation process, laboratory electronic data deliverables are used to ensure that the validation qualifications applied are reflected in the report results tables. These results tables are then used by project teams to make informed decisions about the site. Data validation can help identify on-site trends, discount possible contamination effects, highlight laboratory issues, or describe matrix interferences that may affect on-site contaminants of concern.

Simply put, project teams collect samples to tell the narrative of a site, and validation is a tool that can help make sure the story told is concrete and trustworthy.