Phone No.
(780) 450-3957
Environmental soil sampling should be designed around the question the laboratory results need to answer.
A technically strong laboratory method cannot compensate for a poor sample.
Before collecting soil, define:
PBR's decision framework emphasizes representative sampling, proper containers, preservation and handling because these factors directly affect how confidently laboratory results can support a site-level decision.
A soil test result applies to the sample submitted to the laboratory.
It does not automatically describe an entire:
The sampling plan determines how well the submitted material represents the environmental question being investigated.
For example, a sample collected beside a suspected fuel release may answer a very different question from one collected tens of metres away.
Before sampling, ask:
The answer determines where and how soil should be collected.
A generic sampling approach should not be used simply because it is convenient.
Site history can help identify likely sampling areas.
Consider:
The stronger sequence is:
site history → suspected source → sampling locations → analytical testing
rather than selecting random locations and deciding what the results might mean afterward.
Sampling locations should be selected according to the investigation objective.
Samples may be collected near:
Depending on the site, additional locations may help evaluate whether impacts moved away from the source.
Background samples may sometimes be useful when naturally occurring conditions need to be distinguished from site-related impacts.
Where previous results are elevated, follow-up samples may be used to investigate the surrounding area.
The broader environmental professional should develop the site-sampling design, while PBR can confirm laboratory sample requirements for the analyses being requested.
Contaminants and soil chemistry can vary substantially with depth.
A surface sample may not represent conditions deeper in the soil profile.
Likewise, a deeper contaminated sample does not automatically mean the surface soil has the same concentration.
Sampling depth should therefore reflect:
A surface spill and a leaking underground source could require very different sampling depths.
The laboratory report should therefore be interpreted against the exact depth represented by each sample.
This is one of the most important sampling decisions.
A grab sample represents a defined location and depth.
It may be particularly useful when:
A composite combines material from multiple increments or locations into one laboratory sample.
This can provide an average representation of the combined material.
However, PBR's decision framework specifically warns that compositing can dilute localized contamination.
Imagine one increment contains a high contaminant concentration while several others are low.
Combining them may produce an average result that does not clearly identify the localized hotspot.
The decision should therefore be: Do I need an average condition, or do I need to preserve information about individual locations?
Do not automatically combine soil from areas that differ meaningfully.
Examples may include:
Combining these materials can make interpretation much more difficult.
There is no single number appropriate for every site.
The number of samples depends on:
A small site with one known source may require a different sampling design from a large industrial property with several historical operations.
PBR can confirm laboratory sample requirements, but the environmental professional should design the broader field-sampling strategy.
Sample quantity depends on:
Do not assume that one small container is sufficient for every soil panel.
Contact PBR before field sampling to confirm sample quantity for the requested analysis.
This avoids collecting a sample that cannot support the full analytical program.
Container requirements can vary depending on what is being analyzed.
The wrong container can affect:
Container requirements should therefore be confirmed before going to the field, especially when testing for hydrocarbons, microbiology or other parameters with specific handling needs.
PBR's decision framework identifies container selection and preservation as important workflow considerations.
Sampling equipment and handling practices can introduce contamination if care is not taken.
Potential risks include:
The field procedure should minimize the chance that the sample is affected by material from another location.
Each soil sample should be traceable to its exact field location.
Useful information may include:
A clear identification system reduces the risk of confusing results during interpretation.
The analytical result becomes far more useful when it can be linked accurately to the site.
Document:
Without this context, laboratory values can be difficult to interpret properly.
Field observations do not replace laboratory testing, but they can help the project team understand why a location was sampled.
Examples may include:
These observations should be documented carefully without assuming that visual appearance alone proves contamination.
Storage requirements depend on the analytical test.
Factors may include:
Some parameters are more sensitive to storage conditions than others.
For this reason, PBR should be contacted before sampling so the project team can confirm container type, sample volume/mass, storage, transport, and holding-time considerations.
The appropriate timing depends on the analysis requested.
Some tests may tolerate longer holding periods than others, while microbiological or other sensitive analyses may require more rapid handling.
The safest approach is to plan transportation before sampling begins.
Do not collect samples first and then determine later how or when they will reach the laboratory.
A clear chain-of-custody process helps document:
This is particularly important for environmental projects where several samples and analytical parameters are involved.
Confirm PBR's current submission and chain-of-custody requirements before field work.
Hydrocarbon contamination can be localized and can vary with depth.
Sampling plans may need to consider suspected release area, tank or storage location, spill pathway, vertical migration, nearby locations, and groundwater where relevant.
Composite sampling should be used carefully because averaging may reduce visibility of a localized hydrocarbon hotspot.
Related Service → Petroleum Hydrocarbon Testing in Soil
Metals investigations may need to distinguish potential source areas, background conditions, different soil or fill zones, and different depths.
A detected metal should not automatically be interpreted as industrial contamination because naturally occurring background may be relevant.
Related Service → Metals Testing in Soil
Microbiological samples can be especially sensitive to handling, transport time, temperature, contamination, and sample storage.
The target microbial group should be identified before sampling so PBR can confirm appropriate collection and handling requirements.
Related Service → Soil Microbiology Testing
Follow-up soil sampling should be designed so results can meaningfully support the remediation question.
Consider whether sample locations correspond with initial data, whether depths are comparable, whether the same analytical method is being used, whether untreated or background areas are relevant, and whether residual contamination could be localized.
A lower result in one follow-up sample does not automatically prove site-wide remediation success.
Related Application → Soil Testing for Remediation & Reclamation
Development projects may encounter different fill zones, historic structures, imported material, buried infrastructure, and unexpected soil conditions during excavation.
Samples from meaningfully different materials or locations should not automatically be combined.
Related Application → Environmental Soil Testing for Land Development & Construction
Potentially.
If the contaminant, geology and groundwater conditions create a plausible migration pathway, the environmental investigation may need to consider both matrices.
Soil provides information about the sampled solid matrix. Groundwater provides different information about the water-bearing environment.
One does not automatically substitute for the other.
Before leaving for the field, confirm:
This planning should happen before the first sample is collected.
PBR Laboratories supports soil-testing projects from Edmonton for environmental consultants, industrial facilities, remediation teams, developers and other organizations throughout Alberta, Western Canada and Canada.
PBR can help clients confirm laboratory-side requirements such as:
The project environmental professional should determine the broader site-sampling design and environmental conclusions.
That distinction allows PBR to provide useful technical support without overstating the laboratory's role.
Start with the environmental question, select locations and depths that represent that question, use the appropriate container, avoid cross-contamination, label the sample clearly and follow the laboratory's storage and transport requirements.
The depth depends on the suspected source, release mechanism, site conditions, previous results and investigation objective. There is no universal sampling depth.
The required number depends on site size, variability, source areas, depths and the project decision. One number cannot be applied to every environmental investigation.
A grab sample represents one location or depth. A composite combines several increments and provides an average result for the combined material.
Yes. Combining high- and low-concentration material can dilute localized contamination, which is why compositing should only be used when appropriate for the decision.
Not automatically. Different depths may represent different environmental conditions or contamination profiles.
Container requirements depend on the requested analysis. Contact PBR before sampling to confirm the correct containers.
The required amount depends on the analytical panel and method. Confirm sample quantity with PBR before field sampling.
The appropriate timing depends on the requested test and holding requirements. Transportation should be planned before sampling.
Potentially, where contaminant characteristics and site conditions suggest groundwater impact is plausible.
Before field sampling, tell PBR:
PBR can confirm the applicable sample quantity, containers and laboratory submission requirements before collection.