Section 734.425  Soil Borings

a)         Soil borings must be continuously sampled to ensure that no gaps appear in the sample column.

b)         Any water bearing unit encountered must be protected as necessary to prevent cross-contamination during drilling.

c)         Soil boring logs must be kept for all soil borings.  The logs must be submitted in the corresponding site investigation plan, site investigation completion report, or corrective action completion report on forms prescribed and provided by the Agency and, if specified by the Agency in writing, in an electronic format.  At a minimum, soil boring logs must contain the following information:

1)         Sampling device, sample number, and amount of recovery;

2)         Total depth of boring to the nearest 6 inches;

3)         Detailed field observations describing materials encountered in boring, including but not limited to soil constituents, consistency, color, density, moisture, odors, and the nature and extent of sand or gravel lenses or seams equal to or greater than 1 inch in thickness;

4)         Petroleum hydrocarbon vapor readings (as determined by continuous screening of borings with field instruments capable of detecting such vapors);

5)         Locations of sample(s) used for physical or chemical analysis;

6)         Groundwater levels while boring and at completion; and

7)         Unified Soil Classification System (USCS) soil classification group symbols in accordance with ASTM Standard D 2487-93, "Standard Test Method for Classification of Soils for Engineering Purposes," incorporated by reference in Section 734.120 of this Part, or other Agency approved method.