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An elevated soil test result means the laboratory measured a value above the comparison criterion, specification or reference being used for the project.
It does not automatically tell you:
The next step should be based on the sample, site history, parameter tested, applicable criteria and environmental decision that needs to be made.
PBR’s environmental framework identifies soil testing for metals, hydrocarbons, BTEX, salinity, nutrients, pH and related parameters as supporting site assessment, remediation, reclamation, disposal and land-use decisions.
An elevated result should trigger a defined investigation—not simply an automatic retest.
PBR Laboratories supports environmental soil testing from Edmonton for projects throughout Alberta, Western Canada and Canada.
Before deciding what to do next, confirm:
This sounds basic, but it prevents an investigation from moving forward using the wrong sample, units or comparison value.
PBR’s decision framework specifically warns against using a laboratory report without considering the relevant specification, detection limit, uncertainty or decision rule.
An elevated soil test result means the measured value is above the comparison criterion being used for the project. It does not automatically define the source, extent or required response. Review the sample location and depth, site history, surrounding results and applicable criteria before deciding whether additional sampling, groundwater testing or remediation-related follow-up is appropriate.
“Elevated” should always be tied to a defined comparison.
Depending on the project, that may involve:
A result is not meaningfully “high” simply because the number appears large.
The important question is:
High relative to what criterion, and for what environmental decision?
No.
A laboratory result applies to the submitted sample.
How confidently it can represent a larger site depends on the sampling design, location, depth and site variability. PBR’s framework explicitly requires this limitation to be communicated and identifies non-representative sampling as a major workflow risk.
One elevated sample may indicate:
Additional evidence is needed before deciding which explanation applies.
Ask:
The same numerical result may have very different meaning depending on where it came from.
For example, an elevated result directly beside a historical storage tank answers a different question from the same result in an apparently unaffected background area.
Soil conditions can change with depth.
An elevated surface sample does not automatically mean deeper soil has the same concentration.
Likewise, an elevated subsurface sample does not prove surface soil is equally affected.
When reviewing the result, confirm:
If vertical extent is unknown, additional depth-specific samples may be needed.
Site history can help determine whether there is a plausible source for the elevated result.
Consider:
The analytical result becomes much more useful when it is connected to a credible site history.
One elevated value should be reviewed against surrounding analytical data where available.
Ask:
Patterns can help determine whether the next step should focus on:
If petroleum hydrocarbons are elevated, review:
The next step may involve additional sampling to determine the horizontal or vertical extent.
PBR’s environmental framework specifically identifies hydrocarbons and BTEX as supporting source characterization, remediation planning and confirmation of cleanup progress.
Related Service: Petroleum Hydrocarbon Testing in Soil →
Related Resource: Understanding Petroleum Hydrocarbon Results in Soil →
An elevated metals result requires additional context because many elements occur naturally in soil.
Review:
Do not automatically assume that an elevated metals result proves an industrial source.
Additional background or delineation sampling may be useful depending on the investigation.
If electrical conductivity, sodium adsorption ratio or related soil chemistry is elevated, consider:
Electrical conductivity and sodium adsorption ratio answer different questions, so one should not be used as a substitute for the other.
Related Service: Soil Chemistry Testing →
Related Resource: Soil pH, Electrical Conductivity, SAR & Salinity Explained →
For nitrogen, phosphorus, potassium, sulfur or related soil chemistry, review:
An unexpected nutrient result does not automatically indicate laboratory error.
Additional sampling may be useful if the original sample does not adequately represent the field or zone.
Not automatically.
Retesting should answer a specific question.
For example:
Was there an analytical problem?
is a different question from:
Is the elevated concentration localized at the site?
If the concern is site distribution, repeating the same laboratory sample may provide less useful information than collecting additional representative field samples.
PBR’s decision framework emphasizes selecting follow-up testing around the affected matrix, zone or location and warns against testing that is not aligned with the decision being made.
Additional sampling may be appropriate when:
The goal should be to answer the next environmental question rather than simply produce another laboratory number.
If an elevated result is found at one location, additional samples around that location may help determine whether the condition extends laterally.
A simple decision pathway is:
Elevated sample
↓
Sample surrounding locations
↓
Compare concentrations
↓
Identify where results decline or change
↓
Refine the investigation area
The environmental professional should design the field-sampling program.
PBR can support the laboratory requirements for the selected analyses.
Additional samples at different depths may help determine whether the elevated condition continues below the original sample interval.
This can be particularly relevant for:
Depth-specific results are often more useful than combining different soil intervals into one composite.
Potentially.
Groundwater may need to be considered where:
An elevated soil result does not automatically mean groundwater is affected.
Likewise, a clean soil sample does not automatically establish that groundwater is unaffected.
PBR’s environmental framework identifies environmental water chemistry, metals, nutrients, hydrocarbons and microbiology as supporting source investigation, impact monitoring and remediation decisions.
Use caution.
Composite sampling can provide an average across several increments, but PBR’s decision framework specifically warns that compositing may dilute localized contamination.
For an investigation triggered by one elevated location, compositing several follow-up locations may remove the spatial information needed to understand where the issue occurs.
Ask:
Do we need an average result, or do we need to know exactly which location remains elevated?
That decision should guide the sampling approach.
An elevated post-remediation result should lead to review of:
The next step may involve additional delineation or targeted follow-up testing.
A lower result is useful information, but it does not automatically prove site-wide remediation is complete.
Related Application: Soil Testing for Remediation & Reclamation →
This may indicate:
Do not automatically average the results together.
The isolated elevated result may contain important spatial information.
Additional targeted sampling may help determine whether the result represents a localized hotspot or another site condition.
Review whether the samples are truly comparable.
Check:
A numerical change is difficult to interpret if the underlying samples were collected from different locations or depths.
Use this sequence:
That follows PBR’s decision-first standard: testing should connect the matrix, risk, analytical result and next operational decision.
This page is particularly relevant to:
PBR Laboratories supports analytical soil testing from Edmonton for environmental and land-use projects across Alberta, Western Canada and Canada.
PBR’s documented environmental scope includes soil testing for metals, hydrocarbons, BTEX, salinity, nutrients, pH and related parameters supporting site assessment, remediation, reclamation, disposal and land-use decisions.
PBR's role is to help clients move from:
“The result is elevated.”
to:
“What does this result tell us about the sample, and what testing decision makes sense next?”
That is consistent with PBR’s positioning as a decision-focused laboratory partner serving Alberta and Canada.
It means the measured value is above the comparison criterion or reference being used for the project. It does not by itself determine the source, extent or required response.
No. One result applies to the submitted sample. Additional sampling may be needed to determine whether the condition is localized or broader.
Not automatically. First determine what question the follow-up testing needs to answer. Additional field sampling may sometimes provide more useful information than repeating the same sample.
Confirm the analyte, result, units, comparison criteria, sample location, sample depth and site history.
Additional samples around and below the elevated location may help evaluate horizontal and vertical distribution.
Yes. Combining high- and low-concentration material can dilute localized contamination, which is why compositing should match the specific decision.
Potentially. It depends on the contaminant, depth, geology, groundwater conditions and potential migration pathway.
No. Naturally occurring background concentrations and geology may also be relevant.
Review treatment coverage, sampling location, depth, contaminant distribution and surrounding results before selecting additional testing.
PBR can discuss the soil matrix, target analyte, available analytical testing and laboratory sample requirements for follow-up work. The broader environmental investigation remains project-specific.
When contacting PBR, provide where possible:
PBR can discuss related analytical testing and laboratory sample requirements for the next step.