The Edit That Erases the Evidence
Your field consultant logs CL at 8 to 10 feet - slightly plastic fines, no visible coarse fraction, moderate dry strength in the hand. Lab results arrive three weeks later: ML. Someone in the office opens the boring log, updates the USCS field, types a short note, and files the revision.
The original CL call is gone from the log. Not reconciled - removed. The field observation made at the moment of sample recovery, while the material was intact and at natural moisture, no longer appears in the deliverable. Only the lab result survives.
The data structure made that choice. There was one slot, so only one observation could stay.
Two Observations Made Under Different Conditions
Field USCS classification captures what the consultant observed at recovery: texture at natural moisture, visible structure, plasticity behavior under field conditions. Lab classification applies ASTM D4318 and D422 to a prepared specimen that may have dried during shipping, lost fines during handling, or been remolded for testing. Neither method is wrong. They measure different things at different moments.
When the lab says ML and the field said CL, the most common explanation is not an error. Fine-grained soils near the CL-ML boundary can test differently depending on specimen preparation and the moisture state at the time of field logging. That boundary ambiguity is information - it describes the variability of the material and the limits of both methods at that threshold.
A record that picks one and discards the other is hiding the ambiguity, not resolving it.
What a Single Classification Field Actually Costs
Paper field logs have one USCS box per interval. Excel templates have one USCS column. Most logging software that generates a final PDF gives the same structure: one classification field, last edit wins.
When lab results come in, the practical options are:
- Overwrite the field call with the lab result - the original observation is gone
- Keep the field call and add a text note with the lab result - the note cannot be queried or compared across the site
- Add a parallel column in the source file - breaks the template and creates formatting work
The text note option is the most common, and it produces the least usable data. You cannot generate a report showing every depth interval across a site where field and lab classification diverged without reading through each individual log. On a site with 20 borings, that manual review is not a quick afternoon pass. The discrepancy exists in your data; you just cannot see it without pulling paper. (Version history, where a tool keeps it at all, only recovers the old value as a manual lookup - not as a queryable dataset.)
What Separate Fields Change
When the field USCS call and the lab USCS call are stored as separate fields on the same depth interval record, the workflow changes in a specific way. The field observation stays in its field. The lab result populates a second field when it arrives. Both values appear on the log. The update date and the reviewer who authorized the final designation are part of the same record.
You can generate a comparison across all borings showing every interval where field and lab classification diverged. Filter to fine-grained soils near boundary classifications and patterns start to appear - intervals where a specific depth range shows more variability than expected, or where the boundary ambiguity is consistent enough to warrant a note in the report. Discrepant intervals surface automatically before the log is finalized, rather than appearing as surprises during a QA pass on a stack of PDFs.
The queryability is what changes the work. The discrepancy that used to disappear into a text note becomes a data column you can sort, filter, and report on.
Reconciliation as a Defined Step
For Phase II ESA investigations, boring logs are often reviewed by state environmental agencies and referenced in remedial action plans. The log that shows the field classification, the lab result, and the reviewer's documented reconciliation decision is a materially different document than one that shows a single classification with no visible basis for that designation.
Structuring classification data from the point of field entry - not as a retroactive PDF cleanup step - is what makes that trail auditable. The consultant logs the field call on site. Lab results arrive in the office and populate a matching classification field on the same depth interval record. A report flags every interval where the two designations differ before anyone opens the final log template. The reviewer makes an explicit reconciliation decision on each flagged interval, and that decision attaches to the specific record rather than floating as a general note. The final log carries the complete history: what the field showed, what the lab confirmed, and what designation the project consultant authorized.
The point is to structure classification data as discrete observation fields from the point of field entry, so the field USCS call and the lab result can be kept as separate inputs on the same record - rather than one overwriting the other and surviving only as a hard-to-query revision. LOGitEASY logs boring data at the interval level with discrete classification fields to support that workflow.
Free tier includes standard USCS log templates with no per-seat license cost.
2026-07-10
