1601 FLORIDA DR Geotech Report 2022-10-25

September 10,2017 Infiltration Tests L&A Job No. 17-095 Page 4 copy of which is presented on Plate 3. Detailed descriptions of soils encountered by the test pits are presented in test pit logs on Plates 4 and 5. The test pits, excavated.to 8.5 to 9.0 feet deep, encountered a layer of topsoil, about 10 to 12 inches thick, mantling the site. The topsoil is underlain by a layer of weathered soil of brown to light-brown, medium-dense, silty fine sand with trace to some gravel, about 2.8 to 3.5 feet thick. Underlying the weathered soil to the depths explored is a glaciaF till deposit of light-brown to light-gray, very-dense, cemented, gravelly, silty, fine sand'with occasional cobble. Groundwater Condition Groundwater was not encountered by any of the three.test pits excavated on the project site. The glacial till deposits underlying the site at shallow depth are of extremely low permeability and would tend to perch stormwater infiltrating into the more permeable surficial soils. This perched groundwater would accumulate and rise in the wet winter months and may dry up completely in the dry summer months. IN-SITU INFILTRATION TESTS In-situ Infiltration Test Pits The locations of the two infiltration tests we conducted, IT-1 and IT-2, are shown on Plate 1 attached hereto. The infiltration test pits were located inside the footprint of the proposed access road in between the three test pits, TP-1, TP-2, and TP-3. The infiltration tests were conducted in accordance with the procedure of Small Pilot Test of the Everett Stormwater Code. LIU & ASSOCIATES, INC.