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HomeMy WebLinkAboutDONALD C SCHROEDER #3 UNIT 1 S-4052 Russell Oyster 694-2774 Civil Engineering Soils ~ Foundations Performed for: Name: Legal Depth 0 1 2 ,TNEERING 6' DEVELC, Box 90, Davis St., Eagle River, Alaska 99577 694-2774 or 333-5240 SOIL LOG Mai 1 ing Address: =;:=.,%~_., ,. % ~\_ ~'~ Description: k~... '~_\ ~>~ ',.~:% (feet) Soil .lENT CO. Tel. No. ~/~ m Characteristics Earl Ellis 333-524O Surveying Lan d Development 4 5 6 7 8 lO ll Ground Water Encountered: Yes Proposed Installation: Seepage Pit Comments: , , =' ~.>,~.)~ ~-~, No v~ If yes, what depth Drain Field Performed by: 8)27b ,JANI7 1974 4839 Tampa Circle Anchorage, Alaska 99504 June 2, 1974 Greater Anchorage Area Borough Planning Department 3500 Tudor Road Anchorage, Alaska 99507 Attention: !~. Wayne Mabry Subject-. Soils Evaluation and Related Items - Bacon Subdivision, Unit ~2, Donald C. Schroeder Subdivision 93 Subdivision of TR 9, Donald C. Schroeder Subdivision ~2' Dear }tr. Mabry: The following information concerning the soils conditions for the Proposed Bacon Subdivision located near the Eagle River Road in .Eagle River, is submitted to satisfy the requirements of GAAB Ordi- nance No. 112-72A, Chapter 21; and Title 18, Environmental Conser- vation, 18 AAC 72.060 of the State of Alaska. Test Hole logs and project location maps follow the text. SITE LOCATION ~ND DESCRIPTION. The approximately 34 acre parcel to be 'sUbdivided is located five miles east of the Glenn Highway north of the Eagle River Road. The property is overgrown with Birch, Fir and Cottonwood. The topography is steeply sloping to the south over the entire acreage. EXISTING WELLS AND SUBSURFACE DRAIN FIELDS. Existing wells near the parcel to'be subdivided are not shot. a% on the project location map. Water has been located in this area approximately 85' to 110' below the surface in fractured bedrock. Neighboring sub- divisions (not shown on maP) have wells of sufficient capacity to supply domestic needs. The existance of reliable water sources in this geological area has been proven sufficiently to Borough Officials in the immediate past. Previous chemical and bacterio- logical testing of existing water sources has indicated that drinking water quality standards are satisfied. ~ FIELD EXPLORATION: On },~y 27, 1974, five (5) testholes ~ere excavated on site to depths of 16', 12-1/2', 12' , 7' , and 12-I/2' respectively. The hole locations are sho%~n on the location map. All holes were excavated by Hamann Construction Company of Eagle River, Alaska, using a D-8 Cat Bulldozer and a Case Backhoe with a 1/2 CY bucket. Direct observations were made on soil strata and grab samples were taken both during and after excavation. Testhole placement was made at sufficient locations to insure that soil conditions were as expected.. There is more than sufficient room on the tracts to locate water and wastewater facilities. Greater Anchorage Area Borough Page 2 June 2, 1974 GEOLOGY: The Eagle River drainage area is located within the Chugach Mountains that border Cook Inlet. These mountains are a complex mixture of deformed and metamorphosed sedimentary and igneous rocks deposited during the late Paleozoic and Mesozoic Eras. Five major Pleistocine glacial advances along the consequent or subsequent lacustrine and alluvial deposits greatly influenced the present topography of the area. The surficial geologic unit of the site appears to be' part of the Ea~le River cut as it worked through the late Pleistocene lateral moraine deposits. The till of this deposit is commonly sandy and stoney with cobbles common. Broken rock and sand pre- dominate but silt and rock dust are ever present. Cobbles and rocks are rounded rather than angular except for the shale deposits. SUBSUR_~ACE CONDITIONS. The ground cover over the site generally consists of a few inches of organic°cover underlain with silty sandy gravel with a trace of organics for another four to six feet. The surficial deposits of silty gravels or sandy silty gravels are inter-spersed with cobbles. The upper layer of material is of medium density and the lower level of harder density as evidenced by the effort of the backhoe during excavation. Well graded gravel was found in three holes, poorly graded sand or gravel in the other two holes. The soils in general can be classified as GW/GP/G~ by the Unified Soil' Classification System. The hardpan appears to be a GP soil. Bedrock is found near the surface and is sometimes exposed in the northern most portions of this tract. ~he gravelly soils contain about 70% by weight gravel or. cobbles with the remainder sand and/or silt. GrOundwater was encountered in only one hole as a'seeping flow just above the hardpan layer and not as a saturated level. The water was flowing through the soil and not p°nding. The ground water level is probably at the surface of the hardpan. There is no visible evidence of ponded water, rather the soil appeared to be well drained, but compact. CONCLUSION: Sufficient exploration has been accomplished on this subdiviS£0n for the intended use with individual on-site water and sewer facilities. Each lot has sufficient acreage to allow for replacement soil absorption systems should the initial system fail. The northernmost lots have almost three acres each. ~ The soils are suitable with respect to ~oundation bearing capacity within the range of conventionally applied bearing pressures for residential continuous concrete footings. If other than convent- ional loads are anticipated, professional help may be required to !8 !97(] Greater Anchorage Area Borough Page 3 June 2, 1974 design the foundation. The steep slopes must be considered in any foundation system and road access will be difficult and only possible with the large frontage provided. Please/contact the undersigned if any expansion or clarification of these data is necessary. ...................................................... r ....................... T T--' ' : .................. 1