Branch <br />Hot I N E E R I N G.-- <br />Since 1977 <br />May 30, 2017 <br />Dr. Thomas Dryer <br />2995 Capital Drive <br />Eugene, Oregon 97405 <br />RE: GEOTECHNICAL INVESTIGATION ADDENDUM <br />CAPITAL HILL PUD <br />EUGENE, OREGON <br />BRANCH ENGINEERING INC. PROJECT NO. 14-020 <br />This addendum to our February 6, 2017 Geotechnical/Geological Investigation report is intended <br />to specifically address those items in the South Hills Study that are pertinent to the <br />geotechnical/geological aspects of the proposed Capital Hill Planned Unit Development (PUD) <br />development project. <br />Specifically, the development was evaluated for the potential for surface movement, proposed <br />home sites have been located away from the steeper less stable slopes, and a detailed review of <br />potential for on-site and off-site impacts was performed by a Certified Engineering Geologist as <br />required in Exhibit A of the South Hills Study when a formation is encountered with soil depth <br />exceeding 40 inches and slopes exceed 30 percent. <br />Off-site, there is relatively very low risk of impacts due to the proposed development. The off-site <br />improvements include shallow minor widening of paved roadways fronting the project site, mostly <br />occurring in up-hill cut conditions, and relatively shallow utility construction in existing paved <br />roadways. <br />The subject site is located at the northern end of Capital Drive at latitude 44.03012° north and <br />longitude 123.06034° west. The site is approximately 14-acres in size and the proposed <br />development consists of a subdivision with associated public and private improvements. The <br />majority of the site is above elevation 900 mean sea level at the top of the ridge line that trends <br />north-south between 30th Avenue and Franklin Boulevard. As noted in our February 6, 2017 report, <br />the basic site geology is a volcanic intrusion through sedimentary rock deposits which formed the <br />more erosion resistant ridgeline and caused adverse angles for the softer sedimentary materials <br />on the slopes of the intrusion. <br />On September 30, 2016, BEI engineers and geologists advanced ten (10) exploratory test pits on <br />the development site and conducted a surface reconnaissance of the site and surrounding area. <br />The test pits and observations showed the majority of the development site was underlain by the <br />stable volcanic rock material. One location in the southeast portion of the site was mapped as the <br />upper section of a landslide area; subsequent site design omitted development in this area. <br />The South Hills Study requires site review by a Certified Engineering Geologist (CEG), the on-site <br />test pits were located and logged by both Gary Sandstrom, CEG, Mike Dworsky Staff Engineer, and <br />EUGENE-SPRINGFIELD SALEM-KEIZER <br />310 5th Street, Springfield, OR 97477 p: 541.746.0637 www.branchengineering.com <br />