A map unit is not a borehole
SSURGO links mapped areas to soil components and their properties. It is useful for an initial picture of the land, but its component percentages do not locate each soil within your lot. A coordinate identifies the place you asked about; it does not turn the map into a sample from beneath a footing.
A site report answers a more specific question
For a proposed purchase, construction project or investigation, ask what a site report actually covers: the investigation locations, depths, dates, test methods, assumptions and intended use. Do not assume a report prepared for another part of a development describes the exact building you are reviewing.
Keep a document checklist
Ask for any original geotechnical report, foundation plans, construction records, previous inspections, repair scopes and known drainage or plumbing changes. Availability varies. A missing document is a question to resolve, not proof that work was defective.
Make the comparison explicit
Place the soil-map name and source vintage beside the actual site documents. Note disagreements and ask a qualified local professional what evidence should resolve them. Neither a low mapped class nor a reassuring map color is a substitute for investigating significant symptoms.
Sources and interpretation
Explanations and workflow are our own. This is educational screening, not a site investigation or engineering recommendation.