Those portions of the soil or geologic investigation that constitute “civil engineering” as defined by Cal. Bus. & Prof. Code § 6734 shall be conducted by or under the direct supervision of a geotechnical engineer or civil engineer. Those portions of the investigation that involve the practice of “geology” as defined by Cal. Bus. & Prof. Code § 7802 shall be conducted by an engineering geologist.

The investigations shall be based on observations and tests of the material exposed by exploratory borings or excavations and inspections made at appropriate locations. Additional studies may be necessary to evaluate soil and rock strength, the effect of moisture variation on soil, bearing capacity, compressibility, expansiveness, stability, keying, subdrainage benching and other factors. Grading factors such as moisture variability, ability to compact the material when wet, etc., should be evaluated.