Agenda - Council - 09/14/2021 - Laserfiche WebLink

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HGTS completed a Phase I Environmental Site Assessment in conjunction with this geotechnical exploration. Results of the Phase I ESA are presented under separate cover under HGTS project number 21-0560. 1.5 Documents Provided We were provided a site plan titles "Concept Plan 9" (Concept Plan) that as prepared by Pioneer Engineering and was dated October 19, 2019. The Concept Plan was not signed. The Concept Plan showed a layout of the proposed development superimposed onto an aerial photograph that also included topographic contours. The proposed soil boring locations were hand sketched onto the Concept Plan. We were also provided a topographic map of the project site with some of the surrounding areas also included on the map. The soil boring locations and ground surface elevations at the boring locations were also shown on the map. The map appeared to be a portion of a larger map and was not signed or dated however we understand the map was prepared by Carlson McCain. Other than the documents described above, specific architectural, structural or civil plans were not provided. 1.6 Locations and Elevations The soil boring locations was selected and staked in the field by Carlson McCain. The approximate locations of the soil borings are shown on Figure 1, "Soil Boring Location Sketch," in the Appendix. The sketch was prepared by HGTS using an aerial image obtained from Google Earth as a base. HGTS obtained ground surface elevations and coordinates at the boring locations using GPS technology based on the MN County Coordinate System (Anoka County). GPS coordinates and ground surface elevations are shown on Figure 2 in the Appendix. 2.0 FIELD PROCEDURES Twelve (12) standard penetration test borings were advanced on July 21st and 22nd, 2021 by HGTS with a rotary drilling rig, using continuous flight augers to advance the boreholes. Representative samples were obtained from the borings, using the split -barrel sampling procedures in general accordance with ASTM Specification D-1586. In the split -barrel sampling procedure, a 2-inch O.D. split -barrel spoon is driven into the ground with a 140- pound hammer falling 30 inches. The number of blows required to drive the sampling spoon the last 12 inches of an 18-inch penetration is recorded as the standard penetration resistance value, or "N" value. The results of the standard penetration tests are indicated on the boring logs. The samples were sealed in containers and provided to HGTS for testing and soil classification. A field log of each boring was prepared by HGTS. The logs contain visual classifications of the soil materials encountered during drilling, as well as the driller's interpretation of the subsurface conditions between samples and water observation notes. The final boring logs 2