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2.5 Hand.Cone Penetrometer Probes A series of hand cone penetrometer probes was completed around the perimeter of the house and screened porch, at the locations shown on Figure 2. These probes were completed by pushing a steel rod with a cone - shaped tip into the ground and measuring the resistance of the soils to penetration by the tip as the probe is advanced. The relative density of the shallow sandy soils was then estimated. In general, very loose to loose sandy soils were encountered around the perimeter of the house to depths up to 42 inches below grade. The hand cone penetrometer data are summarized in Appendix C. 2.6 Floor Elevation Survey A floor elevation survey of the house interior was conducted in conjunction with the site inspection/damage assessment. The survey was completed using a manometer to measure relative floor elevations at locations inside the house. The data were normalized relative to a base station datum of zero (0). The data were then plotted on a scaled map of the interior of the house and used to construct a floor elevation contour map, which is shown on Figure 4. During the floor elevation survey, two floor slabs were identified, including the main interior portion of the house and the garage. Data collected over the house interior indicate an overall elevation differential of 1.0 inch across the slab. In the house interior, the pattern of elevation contours shows a minor low area in the living room and northwest bedroom. Local elevation gradients of up to 0.6 inch over 4 feet show a potentially anomalous slope in the southern portion of the living room. In the garage, an overall elevation differential of 0.3 inch was measured across the floor slab. It is a common construction practice to slope garage floor slabs outward to promote proper drainage.. Data from the floor elevation survey indicate the garage floor is essentially flat and level. 2.7 Soil Survey Map Review Soils data from the Soil Survey of Pasco County, Florida (USDA -SCS, 1982) were reviewed as part of the subsidence investigation. The mapped soil unit in the vicinity of the Barker residence was identified as Pomona fine sand (map symbol 2). Pomona soils are nearly level, poorly drained soils found on low ridges in the flatwoods. Typically, the soil unit has a surface layer of black fine sand about 6 inches thick, underlain by gray, grayish brown and brown fine sand, light olive gray fine sandy loam and gray loamy fine sand extending to a depth of 80 inches or more below native grade. In most years, the water table is within a depth of 10 inches below native grade for 1 to 3 months and is at a depth of 10 to 40 inches below native grade for 6 months or more. 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. Therefore, the USDA soil units may not be accurate on the scale of a single residence, and may not correspond to the hand auger and SPT boring results found in our investigation. However, 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 Standard Penetration Test Borings Three standard penetration test (SPT) borings, SPT -1 to SPT -3, were completed at the Barker residence on February 9, 2009, at the locations shown on Figure 2. Boring SPT -1 was located along the east wall of the house, near the southeast corner, and was completed to a depth of 45 feet below grade. Boring SPT -2 was located along the south side of the house, near the southeast corner, and was completed to a depth of 45 feet below grade. Boring SPT -3 was located along the west wall of the house and was completed to a depth of 60 feet below grade. Subsidence Investigation BCI Project No.: 19 -17094 Barker Residence March 2009 Claim No.: 3428 Page 4