1 the Neighbors' findings and evidentiary challenges represent a classic battle of <br />2 the experts, and that the hearings official is entitled to choose which expert <br />3 testimony to believe, as long as the testimony chosen constitutes substantial <br />4 evidence. The Dreyers argue that the hearings official adequately explained <br />5 why she chose to rely on the Geotechnical Investigation. That explanation cited <br />6 the measures recommended by the Geotechnical Investigation, one of which <br />7 was for a "case-by-case" professional evaluation of specific building <br />8 foundations on the steeper lots. <br />9 As noted above, the Neighbors' expert consultant criticized the <br />10 Geotechnical Investigation as inadequate or incomplete, in part because it relied <br />11 upon a cluster of 10 test pits located in the more gently sloped center of the <br />12 property, encompassing only 20 percent of the property, and did not dig test pits <br />13 or evaluate soil stability on the steeper slopes, including on or near the two sites <br />14 identified as showing evidence of landslide activity. The Geotechnical <br />15 Investigation acknowledges that the test pits "represent a very small portion of <br />16 the site" (Record 4757), but elsewhere states that it assumes that the 10 test pits <br />17 "are representative of the subsurface conditions throughout the site." Record <br />18 4754. However, the basis for that assumption is not explained. As noted, the <br />19 site plan was subsequently revised to eliminate a private road near an identified <br />20 landslide area, but as the Neighbors point out the revised site plan still proposes <br />21 a private driveway and residential development in that area. Although the <br />22 Dreyers' expert later submitted supplemental information, the Dreyers do not <br />Page 37 <br />