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2.7 Soil Survey Map Review Soils data from the Soil Survey of Pasco County (USDA-NRCS, 2008) were reviewed as part of the subsidence investigation. The mapped soil unit at the subject property was identified as the Tavares sand, 0 to 5 percent slopes (map unit 6). According to the NRCS, Tavares soils are moderately well drained, sandy eolian and marine deposits found on ridges and knolls on marine terraces. Typically this soil unit consists of sand extending from the ground surtace to 80 inches below native grade. The water table typically occurs at depths ranging from 42 to 72 inches below native grade. The USDA Natural Resources Conservation Service classifications are based on an interpretation of aerial photographs and widely-spaced hand auger borings. Borders between mapping units are approximate and the transition between soil types may be very gradual. Areas of dissimilar soils can occur within a mapped unit. The soil survey provides a good basis for an initial evaluation of shallow soil conditions in the area and can provide an indication of changes that may have occurred due to land filling, excavation, and other activities at the site. 2.8 Hand Auger Borings Four shallow hand auger borings, HA-1 to HA-4, were completed during the site inspection, at the locations shown on Figure 2. The hand auger borings were advanced to depths ranging from l0 to 11 feet below grade. The borings generally encountered variably colored fine-grained quartz sand with local traces of silt, extending to depths of 9 to 10 feet below grade. In borings HA-1 and HA-4, a layer of clayey sand was encountered below the surficial sands, extending to the boring termination depths. The water table was not encountered in the hand auger borings. Soil boring logs are included in Appendix C. 2.9 Standard Penetration Test Borings Four standard penetration test (SPT) borings, SPT-1 to SPT-4, were completed at the subject property on February 17, 2010, at the locations shown on Figure 2. Boring SPT-1 was located on the west side of the building and was completed to a depth of 60 feet below grade. Boring SPT-2 was located near the northwest corner of the building and was completed to a depth of 51%2 feet below grade. Boring SPT-3 was located on the north side of the building, near the northeast corner, and was completed to a depth of 60 feet below grade. Boring SPT-4 was located on the east side of the building and was completed to a depth of 45 feet below grade. The borings were located near areas of observed distress or possible settlement. Drilling services were provided by Independent Drilling, Inc., using a limited-access, track- mounted drilling rig. Each boring was completed in general accordance with ASTM D 1586 using the mud rotary drilling method. Soil samples were collected from each borehole using a l.5-inch ID split-spoon sampler driven with a 140-pound slide hammer falling a distance of 30 inches. A BCI geologist familiar with field procedures and soil classification logged each boring in the field. Soil samples were placed in sealed jars and returned to BCI's office for further classification. Upon completion, each borehole was plugged with cement-bentonite grout. Boring logs are included in Appendix C. �_?s;s;c�e,c� �E�.esti��ti€,3s �3C1 Prc�jecT I`��o. x'.;;;-;�(�i:; (:1l'c ta�� i�41E} �UiT? ��c€i(';7. ft SC){:i��( i;il iili:Ci?'��C}t'?�T�Cs /;�1 i�i �!1��:. i�i:'is'� j`IE. i�'i;`:'1<',iS�; �-' s ;:�Yf' _3