Technical Briefs

The Question

Can environmental decisions be trusted if the underlying data have not been properly validated?

Why It Matters

A municipality, utility, or property owner receiving laboratory results showing an elevated contaminant concentration often faces immediate pressure to act corrective measures, regulatory notifications, and public communication may all depend on that single number. But before any of those steps are taken, one question must be answered first: can the data themselves be trusted?

An unexpected result is not automatically an incorrect one, but it should never be accepted without verification. This is the foundation of environmental quality assurance and quality control (QA/QC), and it is the difference between a decision built on solid evidence and one built on an unconfirmed assumption.

Technical Perspective

Although quality assurance procedures are largely invisible to the public, they play a critical role in determining whether analytical results can be trusted.

During routine environmental laboratory operations, an unexpectedly elevated contaminant result required additional quality verification before it could be confidently reported. Before drawing any conclusion about what the number meant environmentally, the first step was to evaluate whether the number itself was reliable.

That evaluation followed a consistent sequence: confirming that instrument calibration met acceptance criteria, checking that method blanks showed no contamination introduced during sample preparation or analysis, and reviewing the chromatographic peak for proper shape, consistent retention time, and freedom from interferences that could affect compound identification. The result was then compared against duplicates, quality control samples, and, where available, historical or related data to determine whether the finding was consistent or genuinely anomalous.

When uncertainty remained, the appropriate response was neither to assume the result was correct nor to dismiss it outright it was to perform an additional confirmatory analysis. A second instrumental analysis confirmed that the elevated result was valid, and only then was the finding reported as a final result.

An environmental result does not become reliable simply because an instrument detects it. It becomes reliable once the supporting evidence demonstrates that it can be trusted.

Key Considerations

• Calibration and blanks come first. Before interpreting any result, instrument calibration and method blanks must meet established acceptance criteria.
• Peak quality matters. Retention time, peak shape, and the absence of interferences all affect whether a detection is reliable.
• Context confirms or challenges a result. Duplicates, quality control samples, and historical data help determine whether an unusual result is consistent or genuinely anomalous.
• Confirmation is a decision point, not a delay. A second analysis is not a failure of the first it is how laboratories distinguish a true finding from an artifact.
• Most results are routine and that is exactly why exceptions deserve scrutiny. Across thousands of environmental samples spanning drinking water, wastewater, production water, and other matrices, the large majority of results meet all quality criteria without issue. It is precisely because exceptions are uncommon that they warrant a closer look before being reported.

The objective of quality assurance is not to question every result it is to ensure that every reported result can be defended with confidence.

Conclusion

Reliable environmental decisions begin with reliable data. Before communities invest resources, implement corrective actions, or communicate potential health risks, they must be confident that the analytical results accurately represent the environmental conditions they are meant to describe. Validating analytical data is not merely a laboratory requirement it is a fundamental step in protecting public health and supporting responsible environmental decision-making.

What happens after a PFAS result exceeds the limit?

Many people assume the challenge is detecting PFAS. In reality, for many small water systems, schools, and rural communities, the real challenge begins after the result arrives.

Based on documented professional experience in environmental analytical chemistry and water quality, discussions often move immediately toward treatment technologies: granular activated carbon (GAC), ion exchange, reverse osmosis, and other solutions. While these technologies can be effective, there is a fundamental question that is often overlooked: can the community realistically implement, operate, and maintain them?

Many small systems operate with limited staff, limited technical resources, and limited budgets. A corrective action plan cannot simply be a list of technologies. It must be a realistic path that considers the characteristics of the water system, available resources, long-term sustainability, and the protection of public health.

Before deciding on a solution, it is important to understand:

• Is the result representative and consistent?
• What is the likely source of contamination?
• What level of exposure exists?
• What resources are available to the system?
• Are there interim actions that can reduce risk while long-term solutions are evaluated?

Water quality challenges rarely have a one-size-fits-all answer. The question is not always “What is the best treatment technology?” Often, the most important question is: what can this community realistically do?

This is where environmental data interpretation, risk communication, and technical guidance become essential tools for protecting public health.