Allowable soil bearing capacity for Whatcom County is 1,500 psf. For most residential and commercial projects this soil bearing capacity is satisfactory. If your structure requires more than 1,500 psf you will be required to provide a Geotechnical report from an Engineer.
Larger structures such as Cell Towers, Industrial Manufacturing Equipment, structures over three stories in height, and like structures require an engineer's soils report.
There are also small areas of the county where questionable soils exist, like expansive soils, high ground water tables, or areas that were over excavated or where soil waste and debris has been deposited. These areas would also require an engineer's soils report. These areas are not common and you would be notified at the time of permit submittal if the building official is going to require an engineer's soils report.