GEOLOGIC/GEOTECHNICAL INVESTIGATION FOR TENTATIVE MAP LAVENIDA SUBDIVISION (APN # ) ORINDA, CALIFORNIA

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1 GEOLOGIC/GEOTECHNICAL INVESTIGATION FOR TENTATIVE MAP LAVENIDA SUBDIVISION (APN # ) ORINDA, CALIFORNIA

24 A 580 Ts 590 HMA HMA-2 70 Ts 610 Ts HMA-3 HLA-5 GJA-6 LD-2 23 HMA GJA-7 LD Qc Landslide A Ts Qls HMA-6 HMA HLA-4 Ts 660 af LD-5 HLA-8 Qls 30 HMA-15 HMA-7 Qc 29 GJA LD-4 LD Ts JANUARY 16, 1995 Qc Ts Landslide B HLA Ts Qls? Landslide C HMA-9 Qls? HMA A feet EXPLANATION Soil and Rock Units: Key to Test Borings: Map Symbols: af Artificial Fill - mainly sandy to silty clay with rock fragments Geologic Contact (approximate) Large Diameter Boring Location by Alan Kropp & Assoc. (2009) Qls Landslide -mainly sandy to silty clay with some weathered rock fragments, queried where uncertain Landslide, arrows indicate general direction of movement, boundaries are approximate, queried where existence is uncertain Small DiameterTest Boring Location by Alan Kropp & Assoc. ( 2009) Continuous Core Boring Location by Alan Kropp & Assoc. (2007) Qc Colluvium - mainly sandy to silty clay, may locally contain shallow landslides Ts Siesta Formation - mainly claystone, siltstone and sandstone, with some intermixed tuff (Miocene) 55 Strike and dip of bedrock bedding (all beds are overturned) HMA-5 Test Boring Location by Hallenbeck McKay & Assoc. (1978) Seepage Area HLA-5 GJA-5 * Cross Section Location Test Boring Location by Harding Lawson Assoc. (1990) Test Boring Location by Gribaldo, Jones & Assoc. (1971) Key to Test Pits : TP-15 Test Pit Location by Alan Kropp & Assoc. (2009) LOCATION MAP Geologic Map Lavenida Subdivision Orinda, California Note: Test boring, test pit, and subdrain locations are approximate Date: June 2010 Job Number: A Date: May 2010 FIGURE 1

25 Active Faults and Earthquake Epicenters Lavenida Subdivision Orinda, California FIGURE 2

26 Qac Ts Tcu N SITE Tmb Qac Tmb Tor Qac EXPLANATION Qac Alluvium and Colluvium Ts Siesta Formation Tmc Moraga Formation- sedimentary rocks Tmb Moraga Formation-basalt Feet Fault Traces, dashed where approximately located, queried where uncertain Tcu Tor Contra Costa Group Orinda Formation Geologic Contact (approximate) Reference: Radbruch, D. H., 1969, Areal and Engineering Geology of the Oakland East Quadrangle. Radbruch Geologic Map Lavenida Subdivision Orinda, California FIGURE 3

27 SOIL CLASSIFICATION CHART COARSE-GRAINED SOILS MORE THAN 50% RETAINED ON NO.200 SIEVE FINE-GRAINED SOILS 50% OR MORE PASSES THE NO.200 SIEVE PRIMARY DIVISIONS GRAVELS MORE THAN 50% OF COARSE FRACTION RETAINED ON NO.4 SIEVE SANDS 50% OR MORE OF COARSE FRACTION PASSES NO. 4 SIEVE SILTS AND CLAYS LIQUID LIMIT LESS THAN 50% SILTS AND CLAYS LIQUID LIMIT 50% OR MORE HIGHLY ORGANIC SOILS REFERENCE: Unified Soil Classification System (ASTM D ) CLEAN GRAVELS LESS THAN 5% FINES GRAVELS WITH FINES - MORE THAN 12% FINES CLEAN SANDS LESS THAN 5% FINES SANDS WITH FINES - MORE THAN 12% FINES INORGANIC ORGANIC INORGANIC ORGANIC CRITERIA * Cu 4 AND 1 Cc 3 A Cu < 4 AND/OR 1 > Cc > 3 FINES CLASSIFY AS ML OR MH FINES CLASSIFY AS CL OR CH Cu 6 AND 1 Cc 3 Cu < 6 AND/OR 1 > Cc > 3 FINES CLASSIFY AS ML OR MH FINES CLASSIFY AS CL OR CH PI > 7 AND PLOTS ON OR ABOVE "A" LINE PI < 4 OR PLOTS BELOW "A" LINE LIQUID LIMIT - OVEN DRIED LIQUID LIMIT - NOT DRIED < 0.75 PI PLOTS ON OR ABOVE "A" LINE SECONDARY DIVISIONS GROUP SYMBOL GW GP GM GC SW SP SM SC CL ML OL CH MH OH PT GROUP NAME Well-graded gravel Poorly-graded gravel Silty gravel Clayey gravel Well-graded sand Poorly-graded sand Silty sand Clayey sand Lean clay Silt Organic Clay & Organic Silt Fat clay PI PLOTS BELOW "A" LINE LIQUID LIMIT - OVEN DRIED LIQUID LIMIT - NOT DRIED < 0.75 Elastic silt Organic Clay & Organic Silt PRIMARILY ORGANIC MATTER, DARK IN COLOR, AND ORGANIC ODOR Peat * Criteria may be done on visual basis, not necessarily based on lab testing A C u = D 60 /D 100 & C c = (D 30 ) 2 / (D 10 x D 60 ) SILTS AND CLAYS U. S. STANDARD SERIES SIEVE CLEAR SQUARE SIEVE OPENINGS /4" 3" 12" SAND GRAIN SIZES GRAVEL FINE MEDIUM COARSE FINE COARSE COBBLES BOULDERS ABBREVIATIONS INDEX TESTS LL - Liquid Limit (%) (ASTM D ) PI - Plasticity Index (%) (ASTM D ) Passing No. 200 Sieve (%) (ASTM D ) STRENGTH TESTS PP - Field Pocket Penetrometer test of unconfined compressive strength (tsf) TV - Field Torvane test of shear strength (psf) UC - Laboratory unconfined compressive strength (psf) (ASTM D ) TXUU - Laboratory unconsolidated, undrained triaxial test of undrained shear strength (psf) (ASTM D a) MISCELLANEOUS ATOD - At time of drilling psf/tsf - pounds per square foot / tons per square foot psi - pounds per square inch (indicates relative force required to advance Shelby tube sampler) SYMBOLS Standard Penetration Test Split Spoon (2-inch O.D.) Modified California Sampler (3-inch O.D.) Thin-walled Sampler Tube (either Pitcher or Shelby) (3-inch O.D.) Rock Core Bag Sample Groundwater Level ALAN KROPP & ASSOCIATES Geotechnical Consultants KEY TO EXPLORATORY BORING LOGS PROJECT NO. LAVENIDA SUBDIVISION Orinda, California DATE A June 2010 FIGURE 4

28 CONSOLIDATION OF SEDIMENTARY ROCKS; usually determined from unweathered samples. Largely dependent on cementation. U = unconsolidated P = poorly consolidated M = moderately consolidated W = well consolidated BEDDING OF SEDIMENTARY ROCK Splitting Property Massive Blocky Slabby Flaggy Shaly or platy Papery FRACTURING Intensity Very little fractured Occasionally fractured Moderately fractured Closely fractured Intensely fractured Crushed HARDNESS Thickness Greater than 4.0 feet 2.0 to 4.0 feet 0.2 to 2.0 feet 0.05 to 0.2 feet 0.01 to 0.05 feet Less than 0.01 feet Size of Pieces in Feet Greater than 4.0 feet 1.0 to 4.0 feet 0.5 to 1.0 feet 0.1 to 0.5 feet 0.05 to 0.1 feet Less than 0.05 feet Stratification Very thick-bedded Thick-bedded Thin-bedded Very thin-bedded Laminated Thinly laminated 1. Soft - Reserved for plastic material alone. 2. Low Hardness - Can be gouged deeply or carved easily by a knife blade. 3. Moderately Hard - Can be readily scratched by a knife blade; scratch leaves a heavy trace of dust and is readily visible after the powder has been blown away. 4. Hard - Can be scratched by a knife blade with difficulty; scratch produces little powder and is often faintly visible. 5. Very Hard - Cannot be scratched by a knife blade; leaves a metallic streak STRENGTH 1. Plastic - Very low strength. 2. Friable - Crumbles easily by rubbing with fingers. 3. Weak - An unfractured specimen of such material will crumble under light hammer blows. 4. Moderately Strong - Specimen will withstand a few heavy hammer blows before breaking. 5. Strong -Specimen will withstand a few heavy ringing hammer blows and will yield with difficulty only dust and small flying fragments. 6. Very Strong -Specimen will resist heavy ringing hammer blows and will yield with difficulty only dust and small flying fragments. WEATHERING - the physical and chemical disintegration and decomposition of rocks and minerals by natural processes such as oxidation, reduction, hydration, solution, carbonation, and freezing and thawing. D. Deep - Moderate to complete mineral decomposition; extensive disintegration; deep and thorough discoloration; many fractures, all extensively coated or filled with oxides, carbonates and/or clay or silt. M. Moderate - Slight change or partial decomposition of minerals; little disintegration; cementation little to unaffected. Moderate to occasionally intense discoloration. Moderately coated fractures. L. Little - No megascopic decomposition of minerals; little or no effect on normal cementation. Slight and intermittent, or localized discoloration. Few stains on fracture surfaces. F. Fresh - Unaffected by weathering agents. No disintegration or discoloration. Fractures usually less numerous than joints. ALAN KROPP & ASSOCIATES Geotechnical Consultants PHYSICAL PROPERTIES CRITERIA FOR ROCK DESCRIPTIONS LAVENIDA SUBDIVISION Orinda, California PROJECT NO. DATE FIGURE A June

30 proposed grade 1:1 projection from toe of slope to downslope base of keyway Max. 2 1 existing grade (idealized) bedrock surface (idealized) 10 ft minimum (typical) 2% minimum (typical) 3 ft minimum layer of compacted, impervious soils NOTES: 3 ft minimum into rock 2 % minimum and 15 ft minimum for keyway geotextile overlapped 1. This is an idealized cross-section through a typical fill slope, representing idealized subsurface conditions. It is not to scale and has not been developed from site specific information. Significant variations may be encountered during construction. 2. Dimensions of keyways and benches are subject to approval in the field by the geotechnical engineer's representative Subdrains may not be needed on each bench; number and location of subdrain (s) should be determined in the field by the geotechnical engineer's representative at the time of construction. Slopes steeper than 3:1 (horizontal to vertical) should be constructed with geogrid reinforcement. SUBDRAIN DETAIL (TYPICAL) ALAN KROPP & ASSOCIATES Geotechnical Consultants 3/4-inch, clean, open-graded drainrock; wrapped in an approved non-woven polyester geotextile 4-inch rigid, perforated plastic pipe, placed with holes down, on maximum of 6 inches of bedding, with at least a 2% slope. The perforated pipe system should be connected to a solid pipe system (joints glued where sloping >3:1). Provide cleanouts at "high" ends. NOT TO SCALE TYPICAL FILL PLACEMENT ON SLOPES LAVENIDA SUBDIVISION Orinda, California PROJECT NO. DATE A June 2010 FIGURE 7

32 APPENDIX A P/A Design Resources, Inc. Preliminary Grading & Drainage Plan and Cross Section

35 APPENDIX B Logs of Test Pits TP-1 through TP-20

36 TP-1 0 S49W REDDISH BROWN GRAVELLY CLAY (CL) stiff, moist, with numerous siltstone, sandstone, and basalt fragment (Fill) 5 BLACK SILTY CLAY (CH) very stiff, wet, with roots and few gravels and cobbles (Surficial Soil) BROWN GRAVELLY CLAY (CL) medium stiff to stiff, wet gravels are mainly siltstone and sandstone fragments to 4 diameter, with few basalt cobbles (Landslide Debris?) 20 TP-2 S54W 0 BLACK SILTY CLAY (CH) very stiff, wet, with roots, with few gravels and numerous roots (Surficial Soil) 5 10 Slight seepage BROWNISH GRAY CLAY (CL) stiff, wet, with few roots, with decomposed siltstone fragments (deeply weathered, Siesta Formation) 15 ORANGEISH BROWN SILTSTONE closely fractured, friable, moderately weathered, tight; with interbedded reddish brown sandstone, friable, deeply weathered (Siesta Formation) Bedding: N80W40S ALAN KROPP & ASSOCIATES JOYCE ASSOCIATES SCALE IN FEET LOGS OF TEST PITS TP-1 and TP-2 Lavenida Subdivision Orinda, California PROJECT NO. DATE A June 2010

37 TP-3 0 S45W BLACK SILTY CLAY (CH) very stiff, wet, with roots and few gravels (Surficial Soil) 5 10 Gray Tuff 2 thick friable, sandy (Siesta Formation) OLIVE BROWN GRAVELLY CLAY (CL) very stiff, wet, with roots (Surficial Soil) REDDISH BROWN SANDY TO CLAYEY SILTSTONE, closely fractured, friable, moderately weathered; tight, wet, with interbedded silty sandstone and tuff (Siesta Formation) Bedding: N80W07SW TP-4 S55W 0 BLACK SILTY CLAY (CH) very stiff, wet, with roots and few gravels (Surficial Soil) GRAYISH TO REDDISH BROWN SANDY SILTSTONE AND SILTY CLAYSTONE, closely fractured, friable, moderately weathered, tight, moist to wet, with thin bed of silty fine-grained sandstone, friable, moderately weathered (Siesta Formation) Bedding: N45W26SW ALAN KROPP & ASSOCIATES JOYCE ASSOCIATES LOGS OF TEST PITS TP-3 and TP-4 Lavenida Subdivision Orinda, California PROJECT NO. DATE A June 2010 SCALE IN FEET

38 TP-5 0 S15W BLACK SILTY CLAY (CH) very stiff, wet, with roots with and few gravels and cobbles (Surficial Soil) 5 BROWNISH GRAY CLAY (CL) stiff, wet, with few roots, with decomposed siltstone fragments (deeply weathered, Siesta Formation) REDDISH BROWN CLAYEY TO SANDY SILTSTONE AND SILTY CLAYSTONE, closely fractured, friable, moderately weathered, locally tuffaceous (Siesta Formation) Bedding: N30W32SW 20 TP-6 S66W 0 BLACK SILTY CLAY (CH) very stiff, wet, with roots, with few gravels and cobbles (Surficial Soil) 5 Tuffaceous Siltstone 10 Slight seepage REDDISH BROWN CLAYEY TO SANDY SILTSTONE AND SILTY CLAYSTONE, closely fractured, friable, moderately weathered, with thin tuffaceous siltstone bed (Siesta Formation) ALAN KROPP & ASSOCIATES JOYCE ASSOCIATES SCALE IN FEET LOGS OF TEST PITS TP-5 and TP-6 Lavenida Subdivision Orinda, California PROJECT NO. DATE A June 2010

39 TP-7 0 N85W BLACK SILTY CLAY (CH) very stiff, wet with roots with few gravels and cobbles (Surficial Soil) 5 Sandstone 10 Slight seepage GRAYISH TO REDDISH BROWN CLAYEY SILTSTONE AND SILTY CLAYSTONE, closely fractured, friable, moderately weathered, tight, moist to wet, with reddish brown sandstone lense (Siesta Formation) 15 Bedding: N46E30NW 20 TP-8 S25W 0 BLACK SILTY CLAY (CH) very stiff, wet with roots and few gravels and cobbles (Surficial Soil, Landslide Debris) 5 Slide plane, 1/4 diameter gray clay seam with polished 10 Seepage REDDISH BROWN SANDY SILTSTONE closely fractured, friable, tight, moderately weathered (Siesta Formation) REDDISH BROWN SANDY SILTSTONE closely fractured, friable, deeply weathered (Landslide Debris) REDDISH BROWN SANDSTONE, friable, moderately weathered, coarsens upward (overturned) (Siesta Formation) ALAN KROPP & ASSOCIATES JOYCE ASSOCIATES SCALE IN FEET LOGS OF TEST PITS TP-7 and TP-8 Lavenida Subdivision Orinda, California PROJECT NO. DATE A June 2010

40 TP-9 0 S84W 5 BLACK SILTY CLAY (CH) very stiff, wet, with roots, and few gravels (Landslide Debris) 10 REDDISH BROWN GRAVELLY SILTY CLAY (CL) hard, moist, with numerous angular siltstone fragments to 4 diameter (Landslide Debris) TP-10 S45W 0 5 DARK BROWN TO REDDISH BROWN SILTY CLAY (CH) stiff, wet with numerous angular basalt boulders to 6 diameter (Fll) Seepage ALAN KROPP & ASSOCIATES JOYCE ASSOCIATES SCALE IN FEET LOGS OF TEST PITS TP-9 and TP-10 Lavenida Subdivision Orinda, California PROJECT NO. DATE A June 2010

41 TP-11 0 S31W BLACK SILTY CLAY (CH) very stiff, wet with roots and few gravels and cobbles (Surficial Soil) 5 Sandstone YELLOWISH BROWN TO BROWN CLAYEY SILTSTONE AND SILTY CLAYSTONE, closely fractured, friable, moderately weathered, moist, tight, deeply weathered in upper foot with thin brown sandstone bed, friable, (Siesta Formation) Bedding: N60W26SW 20 TP-12 S54W 0 BLACK SILTY CLAY (CH) very stiff, wet with roots and few gravels and cobbles (Surficial Soil) 5 10 BROWN SILTY CLAYSTONE, closely to intensely fractured, friable, moderately weathered, moist, tight (Siesta Formation) Contact (Bedding): N52W70SW LIGHT GRAY SANDSTONE, moderately fractured, friable, moderately weathered, dry, tight, medium grained (Siesta Formation) ALAN KROPP & ASSOCIATES JOYCE ASSOCIATES SCALE IN FEET LOGS OF TEST PITS TP-11 and TP-12 Lavenida Subdivision Orinda, California PROJECT NO. DATE A June 2010

42 TP-13 0 S53W BLACK SILTY CLAY (CH) very stiff, wet with large roots and few gravels and cobbles (Surficial Soil) 5 10 REDDISH BROWN CLAYEY SILTSTONE, closely fractured, friable, moderately weathered, moist, tight (Siesta Formation) TP-14 S23W 0 BLACK SILTY CLAY (CH) very stiff, wet, with roots and few gravels and cobbles (Surficial Soil) 5 REDDISH BROWN SILTY CLAY (CH) stiff, wet, with fine roots (Surficial Soil) BROWN SILTY CLAYSTONE, closely fractured, friable, moderately to deeply weathered, wet, with decomposed zones along fractures, with gray clay films on fracture surfaces (Siesta Formation) ALAN KROPP & ASSOCIATES JOYCE ASSOCIATES SCALE IN FEET LOGS OF TEST PITS TP-13 and TP-14 Lavenida Subdivision Orinda, California PROJECT NO. DATE A June 2010

43 TP-15 0 S39W Slide plane ends BLACK SILTY CLAY (CH) very stiff, wet, with large roots, few gravels and cobbles (Landslide Debris) 5 BROWN SILTY CLAY (CL) very stiff, wet, with roots (Surficial Soil) 10 BROWN SILTY CLAYSTONE, closely fractured, friable, moderately weathered, moist, tight (Siesta Formation) TP-16 S40W 0 BLACK SILTY CLAY (CH) very stiff, wet, with roots, with few gravels and cobbles, no boulders with pressure faces (Landslide Debris) BROWN TO GRAYISH BROWN CLAYEY SILTSTONE AND SILTY CLAYSTONE, closely fractured, friable, moderately weathered, tight, moist, deeply weathered in upper foot (Siesta Formation) ALAN KROPP & ASSOCIATES JOYCE ASSOCIATES SCALE IN FEET LOGS OF TEST PITS TP-15 and TP-16 Lavenida Subdivision Orinda, California PROJECT NO. DATE A June 2010

44 TP-17 0 S39W BLACK SILTY CLAY (CH) very stiff, wet, with roots, with and few gravels (Landslide Debris) Faint polished parting 5 10 BROWN SANDY CLAYEY SILT (ML) hard, moist, with numerous angular basalt cobbles to 6 diameter with thick gray clay coats on fissures and cobbles, with white carbonate pockets in upper 2 feet (Pleistocene Debris Flow Deposits) BROWN SILTY CLAYSTONE, closely fractured, friable, moderately weathered, moist, tight (Siesta Formation) 15 TP S36W BLACK SILTY CLAY (CH) very stiff, wet, with roots and few gravels (Surficial Soil) 5 10 OLIVE BROWN SILTY CLAYSTONE, closely fractured, friable to slightly plastic, moderately weathered, moist, tight (Siesta Formation) ALAN KROPP & ASSOCIATES JOYCE ASSOCIATES SCALE IN FEET LOGS OF TEST PITS TP-17 and TP-18 Lavenida Subdivision Orinda, California PROJECT NO. DATE A June 2010

45 TP-19 0 S39W BROWN SANDY CLAYEY SILT (ML) very stiff, wet, with roots (Surficial Soil) 5 DARK OLIVE BROWN CLAYEY SILTSTONE, closely to intensely fractured, moderately weathered, moist, tight (Siesta Formation) BROWN SANDSTONE, moderately fractured, friable, moderately weathered, moist, tight (Siesta Formation) Bedding: N30W16SW 20 TP-20 N69W 0 BLACK SILTY CLAY (CH) very stiff, wet, with roots, with few gravels and cobbles (Surficial Soil) 5 10 DARK OLIVE BROWN TO REDDISH BROWN SILTY CLAYSTONE AND SANDY SILTSTONE, closely fractured, friable, moderately weathered, moist, tight (Siesta Formation) ALAN KROPP & ASSOCIATES JOYCE ASSOCIATES SCALE IN FEET LOGS OF TEST PITS TP-19 and TP-20 Lavenida Subdivision Orinda, California PROJECT NO. DATE A June 2010

46 PLASTICITY INDEX LIQUID AND PLASTIC LIMITS TEST REPORT Dashed line indicates the approximate upper limit boundary for natural soils CL-ML CL or OL CH or OH ML or OL MH or OH LIQUID LIMIT WATER CONTENT NUMBER OF BLOWS MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Dark Reddish Gray Fat CLAY CH Project No Client: Alan Kropp & Associates Project: Lavenida Subdivion Moraga, California Remarks: Source: TP-5 Sample No.: Slide Plane LIQUID AND PLASTIC LIMITS TEST REPORT COOPER TESTING LABORATORY Figure

47 Particle Size Distribution Report in. 3 in. 2 in. 1-1/2 in. 1 in. 3/4 in. 1/2 in. 3/8 in. #4 #10 #20 #30 #40 #60 #100 #140 # PERCENT FINER GRAIN SIZE - mm % COBBLES % GRAVEL % SAND % SILT % CLAY SIEVE SIZE #10 #30 #40 #50 #100 # mm mm mm mm mm mm mm mm mm mm. PERCENT FINER SPEC.* PERCENT PASS? (X=NO) Soil Description Dark Reddish Gray Fat CLAY Atterberg Limits PL= 20.8 LL= 52.4 PI= 31.6 Coefficients D 85 = D 60 = D 50 = D 30 = D 15 = D 10 = C u = C c = Classification USCS= CH AASHTO= Remarks * (no specification provided) Sample No.: Slide Plane Location: Source of Sample: TP-15 Date: Elev./Depth: COOPER TESTING LABORATORY Client: Alan Kropp & Associates Project: Lavenida Subdivion Moraga, California A Project No: Figure

48 PLASTICITY INDEX LIQUID AND PLASTIC LIMITS TEST REPORT Dashed line indicates the approximate upper limit boundary for natural soils CL-ML CL or OL CH or OH ML or OL MH or OH LIQUID LIMIT WATER CONTENT NUMBER OF BLOWS MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Dark Gray Fat CLAY CH Project No Client: Alan Kropp & Associates Project: Lavenida Subdivision Moraga, California Remarks: Source: TP-17 Sample No.: Slide Plane Elev./Depth: 4' LIQUID AND PLASTIC LIMITS TEST REPORT COOPER TESTING LABORATORY Figure

49 Particle Size Distribution Report in. 3 in. 2 in. 1-1/2 in. 1 in. 3/4 in. 1/2 in. 3/8 in. #4 #10 #20 #30 #40 #60 #100 #140 # PERCENT FINER GRAIN SIZE - mm % COBBLES % GRAVEL % SAND % SILT % CLAY SIEVE SIZE 3/8 in. #4 #10 #30 #40 #50 #100 # mm mm mm mm mm mm mm mm mm mm. PERCENT FINER SPEC.* PERCENT PASS? (X=NO) Soil Description Dark Gray Fat CLAY Atterberg Limits PL= 19.9 LL= 57.7 PI= 37.8 Coefficients D 85 = D 60 = D 50 = D 30 = D 15 = D 10 = C u = C c = Classification USCS= CH AASHTO= Remarks * (no specification provided) Sample No.: Location: Slide Plane Source of Sample: TP-17 Date: Elev./Depth: 4' COOPER TESTING LABORATORY Client: Alan Kropp & Associates Project: Lavenida Subdivision Moraga, California A Project No: Figure

50 APPENDIX C Large Diameter Logs LD-1 through LD-5

51 Log of Boring LD-1 Project Name Lavenida Subdiv. Job Number A Drilling Method 24 Bucket Auger Location Orinda, CA Date Completed 8/26/09 Depth 70 ft. Description Elevation ft. ORANGE BROWN SILTY CLAY (CL) very stiff, moist, with roots, with fragments of deeply weathered sandstone (Surficial Soil) 5 10 GRAYISH BROWN SILTY CLAYSTONE, intensely fractured, friable, deeply weathered, moist, tight, with few roots (Siesta Formation) N67E60SE unsheared GRAY BROWN SANDSTONE, moderately fractured, moderately weathered, friable, tight, lightly cemented, fine grained, dry (Siesta Formation) BROWNISH GRAY CLAYSTONE, closely fractured, friable, moderately weathered, moist, tight (Siesta feet: Laminations@N32W28SW 1/4 inch thick seam of gray clay, very stiff, wet, with polished N75W15SW Laminations@N53W10SW Laminations@N53W10SW, becomes very tight grades more silty 15 Becomes gray N12E52W, unsheared GRAY SANDSTONE, moderately fractured, moderately weathered, friable, tight, lightly cemented, medium grained, moist, contacts unsheared (Siesta Formation) GRAY SILTY CLAYSTONE, closely fractured, friable, moderately weathered, moist, very tight (Siesta 21 feet: 23 feet: 24 feet: shear zone with 1/4 inch gray clay seam, very stiff, moist, with polished parting@n45w60sw Becomes little weathered, locally sandy 30 GRAY SANDSTONE, moderately fractured, moderately weathered, friable, tight, lightly cemented, medium grained, moist, coarsens upward, contacts N80W18S (Siesta Formation) GRAY TO REDDISH BROWN SILTY CLAYSTONE, closely fractured, friable, little weathered, moist, very tight (Siesta Formation) 35 with occasional lenses of Gray Sandstone, coarsens upward, upper contact eroded N89E40NW N30W28SW 40 Log of Boring LD-1, 0-40 feet Lavenida Subdivision Orinda, California Job Number: A June 2010

52 Log of Boring LD-1 Project Name Lavenida Subdiv. Job Number A Drilling Method 24 Bucket Auger Location Orinda, CA Date Completed 8/27/09 Depth 70 ft. Description Elevation ft. GRAY TO REDDISH BROWN SILTY CLAYSTONE, closely fractured, friable, little weathered, moist, very tight (Siesta Formation) GRAY TO BROWNISH GRAY SANDY SILTSTONE, closely fractured, friable, little weathered, moist, tight, with small carbonate nodules (Siesta Formation) 45 Becomes locally reddish brown 50 Contact, N10W24NE GRAY SANDSTONE, friable, unweathered, moist, very tight, weakly cemented, coarsens upward, slight seepage (Siesta Formation) Contact, N40W50SW GRAY TO REDDISH BROWN SILTY CLAYSTONE, closely fractured, friable, unweathered, moist, very tight (Siesta Formation) 55 Shear, 1/8 inch seam of hard clay with polished N30E55SE 60 Contact, N25W25SW LIGHT GRAY SANDSTONE, friable, unweathered, moist, very tight, weakly cemented, coarsens upward (Siesta Formation) GRAY TO REDDISH BROWN SILTY CLAYSTONE AND SANDY SILTSTONE, closely fractured, friable, unweathered, moist, very tight (Siesta Formation) 65 N65E43NW 70 Bottom of Boring at 70.0 feet Slight seepage encountered at 48 feet, otherwise dry Boring backfilled with compacted cuttings Log of Boring LD-1, feet Lavenida Subdivision Orinda, California Job Number: A June 2010

53 Log of Boring LD-2 Project Name Lavenida Subdiv. Job Number A Drilling Method 24 Bucket Auger Location Orinda, CA Date Completed 8/27/09 Depth 70 ft. Description Elevation ft. DARK BROWN SILTY CLAY (CL) very stiff, moist, with roots, (Surficial Soil) BROWN CLAYEY SILTSTONE, intensely fractured, friable, deeply weathered, moist, tight (Siesta Formation) 5 within lenses of Gray Sandstone, friable, moderately weathered N47W23SW within lenses of Gray Sandstone, friable, moderately weathered 10 Becomes locally wet Gray clay seam, very stiff, N12W41SW Becomes reddish brown and gray 15 Becomes mainly gray Occasional discontinuous shears at N20W35NE, with faint polished partings, not continuous around hole 20 with occasional concretions N50E48NW, unsheared GRAY SANDSTONE, friable, wet, little weathered, medium to fine-grained, coarsens upward (Siesta Formation) N16W59SW, unsheared Shear zone, 1/8th inch thick clay seam, with polished parting, very stiff, not continuous around hole GRAY AND BROWN SILTSTONE AND CLAYSTONE, closely fractured, friable, little weathered, very tight, moist (Siesta Formation) with occasional discontinuous polished fractures 35 Contact, very N23W41SW, unsheared GRAY SILTY SANDSTONE, closely fractured, friable, little weathered, very tight, with few concretions (Siesta Formation) GRAY AND BROWN SILTSTONE AND CLAYSTONE, closely fractured, friable, little weathered, very tight, moist (Siesta Formation) 40 Log of Boring LD-2, 0-40 feet Lavenida Subdivision Orinda, California Job Number: A June 2010

54 Log of Boring LD-2 Project Name Lavenida Subdiv. Location Orinda, CA Job Number A Date Completed 8/27/09 Drilling Method 24 Bucket Auger Depth 70 ft. Description Elevation ft. GRAY AND BROWN SILTSTONE AND CLAYSTONE, closely fractured, friable, little weathered, very tight, moist (Siesta Formation) With few polished fractures and discontinuous shears N70E43SE, unsheared Four-inch thick bed of Gray Sandstone, friable, unweathered, locally cemented, lower N70W29SW, unsheared GRAY AND BROWN SILTSTONE AND CLAYSTONE, closely fractured, friable, little weathered, very tight, moist (Siesta Formation) 3-inch thick bed of Gray Sandstone, friable, unweathered, irregular, N57W37SW, contacts unsheared GRAY AND BROWN SILTSTONE AND CLAYSTONE, closely fractured, friable, little weathered, very tight, moist (Siesta Formation) N40W40SW, unsheared 6-10 inch thick bed of Gray Sandstone, friable, tight, wet, little weathered N25E49NW, unsheared GRAY AND BROWN SILTSTONE AND CLAYSTONE, closely fractured, friable, little weathered, very tight, moist (Siesta Formation) 4-inch thick bed of Gray Sandy Siltstone, friable, tight, wet, little weathered, N50W34SW GRAY AND BROWN SILTSTONE AND CLAYSTONE, closely fractured, friable, little weathered, very tight, moist (Siesta Formation) Bottom of Boring at 70.0 feet No seepage encountered Boring backfilled with compacted cuttings Log of Boring LD-2, feet Lavenida Subdivision Orinda, California Job Number: A June 2010

55 Log of Boring LD-3 Project Name Lavenida Subdiv. Job Number A Drilling Method 24 Bucket Auger Location Orinda, CA Date Completed 8/28/09 Depth 50 ft. Description Elevation ft. BROWN SILTY CLAY (CL) very stiff, moist, with roots, with fragments of deeply weathered sandstone (Surficial Soil/Fill) 5 REDDISH BROWN SANDY SILTSTONE, intensely fractured, friable, deeply weathered, moist, tight (Siesta Formation, possible landslide debris) with lenses of Light Gray Silty Sandstone, closely fractured, friable, wet tight /8 inch clay seam, medium stiff, wet, with polished N66E49NW Contact, sheared, with thin very stiff clay N25E31NW, slight seepage Clay seam, 1/2-inch thick, stiff, possible slide plane GRAYISH BROWN SANDY SILTSTONE AND CLAYEY SILTSTONE, closely fractured, moderately weathered, friable, tight, moist (Siesta Formation) N27W29SW, 1/2 inch clay seam, very stiff, along contact REDDISH BROWN SANDSTONE, friable, moderately weathered, tight, wet (Siesta Formation) N30W40SW, unsheared, seepage REDDISH-BROWN TO GRAY SANDY TO CLAY SILTSTONE, closely fractured, friable, moderately weathered, tight, moist (Siesta Formation) 20 with lenses of Gray Silty Sandstone, friable, becomes wet 25 varies from moist to wet, with large concretions with thin sandstone beds, N85W38S 30 Six-inch bed of LIGHT GRAY SANDY TUFF, friable, wet, with concretions, N80E23S Seepage 35 GRAY SANDY SILTSTONE, closely fractured, friable, moderately weathered, wet, tight (Siesta Formation) varies from moist to wet grades more sandy 40 Contact, N70E37S. Log of Boring LD-3, 0-40 feet Lavenida Subdivision Orinda, California Job Number: A June 2010

56 Log of Boring LD-3 Project Name Lavenida Subdiv. Job Number A Drilling Method 24 Bucket Auger Location Orinda, CA Date Completed 8/28/09 Depth 50 ft. Elevation ft. 45 Description GRAY SANDY SILTSTONE, closely fractured, friable, little weathered, moist, tight (Siesta Formation) GRAY SANDSTONE, friable, little weathered, tight, seepage (Siesta Formation) N75W40SW, unsheared GRAY SANDY SILTSTONE, closely fractured, friable, little weathered, moist, tight, with concretions (Siesta Formation) 50 Bottom of Boring at 50.0 feet Seepage encountered at 7.5, 16.5, 32, and 41 feet, Water level 48.5 feet 2 hours after drilling Boring backfilled with compacted cuttings Log of Boring LD-3, feet Lavenida Subdivision Orinda, California Job Number: A June 2010

57 Log of Boring LD-4 Project Name Lavenida Subdiv. Job Number A Drilling Method 24 Bucket Auger Location Orinda, CA Date Completed 8/28/09 Depth 49 ft. Description Elevation ft. DARK BROWN GRAVELLY CLAY (CL) very stiff, wet, with numerous angular basalt cobbles to 6 inches diameter, with white carbonate coatings on cobbles (Pleistocene Debris Flow Deposits) 5 matrix becomes reddish brown 10 Contact, base of N5E30E REDDISH BROWN SILTY CLAYSTONE AND CLAYEY SILTSTONE, intensely fractured, friable, deeply weathered, wet, tight (Siesta ft.: 3-inch thick lens of BROWN SANDSTONE, friable, deeply weathered, N10W15E (Siesta Formation) 15 N60W29NE, unsheared BROWN SANDSTONE, friable, medium grained, deeply weathered, moderate seepage, caving (Siesta Formation) 20 Shear Zone, 1/2 inch thick seam of Brown Clay, very stiff, N60E48NW BROWN AND GRAY SILTY CLAYSTONE AND CLAYEY SILTSTONE, intensely fractured, friable, deeply weathered, wet, tight (Siesta Formation) Caving, heavy approximately 5 gpm N88W36N 35 DARK GRAY SANDSTONE, weak, lightly cemented, moderately fractured, little weathered, tight, saturated (Siesta Formation) BROWN AND GRAY SILTY CLAYSTONE AND CLAYEY SILTSTONE, intensely fractured, friable, deeply weathered, wet, tight (Siesta Formation) 40 Log of Boring LD-4, 0-40 feet Lavenida Subdivision Orinda, California Job Number: A June 2010

58 Log of Boring LD-4 Project Name Lavenida Subdiv. Location Orinda, CA Job Number A Drilling Method 24 Bucket Auger Description Date Completed 8/28/09 Depth 49 ft. Elevation ft. BROWN AND GRAY SILTY CLAYSTONE AND CLAYEY SILTSTONE, intensely fractured, friable, deeply weathered, wet, tight (Siesta Formation) Bottom of Boring at 49.0 feet Seepage encountered at 15 and 32 feet, water level one hour after drilling 44 feet Boring backfilled with compacted cuttings Log of Boring LD-4, feet Lavenida Subdivision Orinda, California Job Number: A June 2010

59 Log of Boring LD-5 Project Name Lavenida Subdiv. Job Number A Drilling Method 24 Bucket Auger Location Orinda, CA Date Completed 9/01/09 Depth 55 ft. Description Elevation ft. BROWN SILTY CLAY (CL) hard, moist, with roots, (Surficial Soil) 5 GRAYISH BROWN SILTY CLAYSTONE, intensely fractured, friable, deeply weathered, tight, moist, with white carbonate streaks in upper foot (Siesta Foramtion) locally grades more silty with occasional silty sand lenses inch thick bed of Brown Sandstone, friable, deeply weathered, moist, tight N35W40SW (Siesta Formation) Gray Sandstone lense, 1 inch thick, friable, deeply weathered, moist, tight, N38W25SW (Siesta Formation) inch thick bed of Grayish Brown Sandstone, friable, moderately weathered, tight, N20E25NW (Siesta Formation) 2 inch thick Grayish Brown Sandstone lense, friable, moderately weathered, N20W20SW (Siesta Formation) GRAYISH BROWN SILTY CLAYSTONE, intensely fractured, friable, deeply weathered, tight, moist (Siesta Foramtion) grades to brownish gray, very tight, moist Shear Zone: 1/2 inch seam of Gray Clay, very stiff, wet, with polished N41W30SW with occasional discontinuous gray sandstone lenses 2-inch thick bed of Gray Claystone, friable, little weathered, closely fractured, N20W25SW N35W32SW GRAY SILTY CLAYSTONE, closely fractured, friable, little weathered, tight, (Siesta Formation) becomes medium gray, wet, with occasional concretions, becomes very tight 35 Shear Zone: Thin clay N28E25NW, irregular, discontinuous, with carbonate nodules GRAY SILTY CLAYSTONE, closely fractured, friable, little weathered, tight, (Siesta Formation) N32W35SW 40 Log of Boring LD-5, 0-40 Feet Lavenida Subdivision Orinda, California Job Number: A June 2010

60 Log of Boring LD-5 Project Name Lavenida Subdiv. Location Orinda, CA Job Number A Drilling Method 24 Bucket Auger Description Date Completed 9/01/09 Depth 55 ft. Elevation ft. GRAY SILTY CLAYSTONE, closely fractured, friable, little weathered, tight, (Siesta Formation) with occasional concretions 45 GRAY SILTY CLAYSTONE AND SILTSTONE, closely fractured, friable, little weathered, very tight, (Siesta Formation) Bottom of Boring at 55.0 feet No seepage encountered Boring backfilled with compacted cuttings Log of Boring LD-5, Feet Lavenida Subdivision Orinda, California Job Number: A June 2010

61 APPENDIX D Small Diameter Logs B-1 through B-5

62 DRILL RIG: B-24, Solid Flight Auger SURFACE ELEVATION: 600 feet DEPTH TO GROUNDWATER: (see notes) BORING DIAMETER: 4.5" inches LOGGED BY: GH DATE DRILLED: 9/9/09 DESCRIPTION AND REMARKS COLOR CONSISTENCY SOIL TYPE DEPTH (ft) SAMPLER TYPE SAMPLER BLOW COUNTS MOISTURE CONTENT (%) DRY DENSITY (pcf) OTHER TESTS CLAY, Fat - some silt, some coarse sands, some roots Dark Brown to Black Stiff CH 1 2 LL=52, PI=23 PP = >4.5 tsf [22] 3 CLAY, Fat - with silt, trace roots, moist Greenish Gray with Light Brown and Black Very Stiff CH 4 5 [29] PP = 4.25 tsf CLAYSTONE - friable, deep to moderate weathering, moist Greenish Gray Low Hardness BED ROCK 6 [52] LL=41, PI=23 PP = >4.5 tsf SILTSTONE - friable, moderate weathering, dry Olive Gray Low Hardness BED ROCK [50/6"] 9.1 PP = >4.5 tsf AKA BORING LOG A BORING LOGS.GPJ AKA_TEMPLATE.GDT 6/10/10 -varying siltstone to claystone SANDSTONE - friable, deep weathering, dry Bottom of boring at 16.5 feet. NOTES: 1. No groundwater was encountered at the time of drilling and the boring was grouted following drilling in accordance with Contra Costa County permit requirements. (See report for discussion.) 2. Stratification lines represent the approximate boundaries between material types and the transitions may be gradual. (Continued on Next Page) Olive Gray PROJECT NO A Low Hardness EXPLORATORY BORING LOG LAVENIDA SUBDIVISION Orinda, California DATE June 2010 BED ROCK SHEET 1 of 2 BORING NO. B-1

63 DESCRIPTION AND REMARKS (Continued from Previous Page) COLOR CONSISTENCY SOIL TYPE DEPTH (ft) SAMPLER TYPE SAMPLER BLOW COUNTS MOISTURE CONTENT (%) DRY DENSITY (pcf) OTHER TESTS 3. Penetration resistance values (blow counts) enclosed in brackets ([ ]) were recorded with a 3.0-inch O.D. Modified California sampler; these are not standard penetration resistance values. 4. Elevations were determined from plans drawn by P/A Design Resources. 5. Approximate unconfined compressive strength values were recorded in the field using a pocket penetrometer. These values are shown on the logs and are preceded by the symbol "PP". AKA BORING LOG A BORING LOGS.GPJ AKA_TEMPLATE.GDT 6/10/10 PROJECT NO A EXPLORATORY BORING LOG LAVENIDA SUBDIVISION Orinda, California DATE June 2010 SHEET 2 of 2 BORING NO. B-1

64 DRILL RIG: B-24, Solid Flight Auger SURFACE ELEVATION: 642 feet DEPTH TO GROUNDWATER: (see notes) BORING DIAMETER: 4.5" inches LOGGED BY: GH DATE DRILLED: 9/9/09 DESCRIPTION AND REMARKS COLOR CONSISTENCY SOIL TYPE DEPTH (ft) SAMPLER TYPE SAMPLER BLOW COUNTS MOISTURE CONTENT (%) DRY DENSITY (pcf) OTHER TESTS CLAY, Lean - with silt, some sand, trace roots, dry Black Stiff CL 1 CLAYSTONE - friable, deep to moderate weathering, dry Grayish Brown Low Hardness BED ROCK 2 3 [19] PP = >4.5 tsf Dark Gray to Light Gray with Red Oxidizing 4 [28] PP = >4.5 tsf 5 SILTSTONE - weak, moderate weathering, dry Moderate Hardness BED ROCK PP = >4.5 tsf -increase in clay content 8 [63] 9 CLAYSTONE - friable, deep weathering grades to moderate weathering Light Brown grades to Grayish Brown Low Hardness BED ROCK Bottom of boring at 12.5 feet NOTES: AKA BORING LOG A BORING LOGS.GPJ AKA_TEMPLATE.GDT 6/10/10 1. No groundwater was encountered at the time of drilling and the boring was grouted following drilling in accordance with Contra Costa County permit requirements. (See report for discussion.) 2. Stratification lines represent the approximate boundaries between material types and the transitions may be gradual. 3. Penetration resistance values (blow counts) enclosed in brackets ([ ]) were recorded with a 3.0-inch O.D. Modified California sampler; these are not standard penetration resistance values. 4. Elevations were determined from plans drawn by P/A Design Resources. 5. Approximate unconfined compressive strength values were recorded in the field using a pocket penetrometer. These values are shown on the logs and are preceded by the symbol "PP". PROJECT NO A EXPLORATORY BORING LOG LAVENIDA SUBDIVISION Orinda, California DATE June 2010 SHEET 1 of 1 BORING NO. B-2

65 DRILL RIG: B-24, Solid Flight Auger SURFACE ELEVATION: 652 feet DEPTH TO GROUNDWATER: (see notes) BORING DIAMETER: 4.5" inches LOGGED BY: GH DATE DRILLED: 9/9/09 DESCRIPTION AND REMARKS COLOR CONSISTENCY SOIL TYPE DEPTH (ft) SAMPLER TYPE SAMPLER BLOW COUNTS MOISTURE CONTENT (%) DRY DENSITY (pcf) OTHER TESTS CLAY, Fat - with roots, trace coarse sand, moist to wet Black Firm CH 1 2 PP = 0.5 tsf [7] CLAY, Fat - with coarse sand, fine gravels Dark Brown CH 3 -some coarse sands, fine gravels, roots, moist Stiff 4 5 PP = 2.0 tsf [22] AKA BORING LOG A BORING LOGS.GPJ AKA_TEMPLATE.GDT 6/10/10 -with coarse sands, fine gravels, some white clasts, moist -large claystone piece at 11.5' -increase in fine gravel sized oxidized pieces, trace coarse gravels LANDSLIDE DEBRIS CLAYSTONE - some silt, friable to weak, deep weathering (Continued on Next Page) Mottled Dark Brown with Black, Reddish Brown streaks Mottled Dark Brown, Reddish Brown, Yellowish Brown Bluish Gray with Red Oxidation PROJECT NO A Very Stiff Stiff Low Hardness EXPLORATORY BORING LOG LAVENIDA SUBDIVISION Orinda, California DATE June 2010 BED ROCK [29] [18] [15] [15] SHEET 1 of 2 PP = 3.7 tsf PP = 2.6 tsf LL=61, PI=41 PP = 2.2 tsf PP = 2.8 tsf BORING NO. B-3

66 DESCRIPTION AND REMARKS (Continued from Previous Page) CLAYSTONE - some silt, friable to weak, deep weathering COLOR Bluish Gray with Red Oxidation CONSISTENCY Low Hardness SOIL TYPE BED ROCK DEPTH (ft) 21 SAMPLER TYPE SAMPLER BLOW COUNTS MOISTURE CONTENT (%) 17.2 DRY DENSITY (pcf) OTHER TESTS PP = 3.0 tsf LL=35, PI=13 [31] moderate weathering Bottom of boring at 26.5 feet. Bluish Gray with Greenish Gray and White fissures [55] 13.5 PP = >4.5 tsf NOTES: 1. No groundwater was encountered at the time of drilling and the boring was grouted following drilling in accordance with Contra Costa County permit requirements. (See report for discussion.) 2. Stratification lines represent the approximate boundaries between material types and the transitions may be gradual. 3. Penetration resistance values (blow counts) enclosed in brackets ([ ]) were recorded with a 3.0-inch O.D. Modified California sampler; these are not standard penetration resistance values. 4. Elevations were determined from plans drawn by P/A Design Resources. 5. Approximate unconfined compressive strength values were recorded in the field using a pocket penetrometer. These values are shown on the logs and are preceded by the symbol "PP". AKA BORING LOG A BORING LOGS.GPJ AKA_TEMPLATE.GDT 6/10/10 PROJECT NO A EXPLORATORY BORING LOG LAVENIDA SUBDIVISION Orinda, California DATE June 2010 SHEET 2 of 2 BORING NO. B-3

67 DRILL RIG: B-24, Solid Flight Auger SURFACE ELEVATION: 656 feet DEPTH TO GROUNDWATER: (see notes) BORING DIAMETER: 4.5" inches LOGGED BY: GH DATE DRILLED: 9/9/09 DESCRIPTION AND REMARKS COLOR CONSISTENCY SOIL TYPE DEPTH (ft) SAMPLER TYPE SAMPLER BLOW COUNTS MOISTURE CONTENT (%) DRY DENSITY (pcf) OTHER TESTS CLAY, Lean - with fine to coarse gravels and some cobbles, dry to moist (FILL) Dark Brown Very Stiff CL 1 2 Mottled Brown, Reddish Brown, Olive, Olive Gray, Yellowish Brown 3 4 [35] PP = 3.75 tsf with coarse sand Mottled Yellowish, Dark Brown 8 PP = >4.5 tsf 9 [31] SILTSTONE - friable, moderate weathering FILL Grayish Brown Grayish Brown with Reddish Brown fissures Low Hardness BED ROCK [70] PP = >4.5 tsf AKA BORING LOG A BORING LOGS.GPJ AKA_TEMPLATE.GDT 6/10/10 Bottom of boring at 18.5 feet. (Continued on Next Page) PROJECT NO A 11.7 EXPLORATORY BORING LOG LAVENIDA SUBDIVISION Orinda, California DATE June [50/6"] SHEET 1 of 2 PP = >4.5 tsf BORING NO. B-4

68 DESCRIPTION AND REMARKS (Continued from Previous Page) COLOR CONSISTENCY SOIL TYPE DEPTH (ft) SAMPLER TYPE SAMPLER BLOW COUNTS MOISTURE CONTENT (%) DRY DENSITY (pcf) OTHER TESTS NOTES: 1. No groundwater was encountered at the time of drilling and the boring was grouted following drilling in accordance with Contra Costa County permit requirements. (See report for discussion.) 2. Stratification lines represent the approximate boundaries between material types and the transitions may be gradual. 3. Penetration resistance values (blow counts) enclosed in brackets ([ ]) were recorded with a 3.0-inch O.D. Modified California sampler; these are not standard penetration resistance values. 4. Elevations were determined from plans drawn by P/A Design Resources. 5. Approximate unconfined compressive strength values were recorded in the field using a pocket penetrometer. These values are shown on the logs and are preceded by the symbol "PP". AKA BORING LOG A BORING LOGS.GPJ AKA_TEMPLATE.GDT 6/10/10 PROJECT NO A EXPLORATORY BORING LOG LAVENIDA SUBDIVISION Orinda, California DATE June 2010 SHEET 2 of 2 BORING NO. B-4

69 DRILL RIG: B-24, Solid Flight Auger SURFACE ELEVATION: 630 feet DEPTH TO GROUNDWATER: (see notes) BORING DIAMETER: 4.5" inches LOGGED BY: GH DATE DRILLED: 9/9/09 DESCRIPTION AND REMARKS COLOR CONSISTENCY SOIL TYPE DEPTH (ft) SAMPLER TYPE SAMPLER BLOW COUNTS MOISTURE CONTENT (%) DRY DENSITY (pcf) OTHER TESTS CLAY, Lean - some sand, some roots, dry to moist Mottled Brown, Yellowish Brown, Red Stiff CL 1 2 LL=35. PI=18 PP = >4.5 tsf 3 [20] SILTSTONE - friable, moderate weathering Mottled Grayish Brown, Yellowish Brown Low Hardness BED ROCK PP = >4.5 tsf 5 [41] PP = >4.5 tsf CLAYSTONE - friable, deep to moderate weathering, dry Light Gray with Reddish Brown fissures Low Hardness BED ROCK 9 10 [48] PP = >4.5 tsf Bottom of boring at 13.9 feet. [84/11"] AKA BORING LOG A BORING LOGS.GPJ AKA_TEMPLATE.GDT 6/10/10 NOTES: 1. No groundwater was encountered at the time of drilling and the boring was grouted following drilling in accordance with Contra Costa County permit requirements. (See report for discussion.) 2. Stratification lines represent the approximate boundaries between material types and the transitions may be gradual. 3. Penetration resistance values (blow counts) enclosed in brackets ([ ]) were recorded with a 3.0-inch O.D. Modified California sampler; these are not standard penetration resistance values. 4. Elevations were determined from plans drawn by P/A Design Resources. 5. Approximate unconfined compressive strength values were recorded in the field using a pocket penetrometer. These values are (Continued on Next Page) PROJECT NO A EXPLORATORY BORING LOG LAVENIDA SUBDIVISION Orinda, California DATE June 2010 SHEET 1 of 2 BORING NO. B-5

DESCRIPTION AND REMARKS (Continued from Previous Page) COLOR CONSISTENCY SOIL TYPE DEPTH (ft) SAMPLER TYPE SAMPLER BLOW COUNTS MOISTURE CONTENT (%) DRY DENSITY (pcf) OTHER TESTS shown on the logs and

70 DESCRIPTION AND REMARKS (Continued from Previous Page) COLOR CONSISTENCY SOIL TYPE DEPTH (ft) SAMPLER TYPE SAMPLER BLOW COUNTS MOISTURE CONTENT (%) DRY DENSITY (pcf) OTHER TESTS shown on the logs and are preceded by the symbol "PP". AKA BORING LOG A BORING LOGS.GPJ AKA_TEMPLATE.GDT 6/10/10 PROJECT NO A EXPLORATORY BORING LOG LAVENIDA SUBDIVISION Orinda, California DATE June 2010 SHEET 2 of 2 BORING NO. B-5

71 APPENDIX E Gribaldo, Jones & Associates Logs

76 APPENDIX F Hallenbeck-McKay & Associates Logs

90 APPENDIX G Harding Lawson Associates Logs

98 APPENDIX H Alan Kropp & Associates Core Boring CB-6

100

101

102

103

Depth (ft) USCS Soil Description TOPSOIL & FOREST DUFF

Test Pit No. TP-6 Location: Latitude 47.543003, Longitude -121.980441 Approximate Ground Surface Elevation: 1,132 feet Depth (ft) USCS Soil Description 0 1.5 1.5 5.0 SM 5.0 8.0 SM Loose to medium dense,