SUMMARY OF SOIL CONDITIONS CITYWIDE SIDEWALK IMPROVEMENT PROJECT JIMMY DURANTE BOULEVARD, VIA DE LA VALLE, AND CAMINO DEL MAR DEL MAR, CALIFORNIA

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1 SUMMARY OF SOIL CONDITIONS CITYWIDE SIDEWALK IMPROVEMENT PROJECT JIMMY DURANTE BOULEVARD, VIA DE LA VALLE, AND CAMINO DEL MAR DEL MAR, CALIFORNIA PREPARED FOR NASLAND ENGINEERING SAN DIEGO, CALIFORNIA SEPTEMBER 3, 2014 PROJECT NO. G

2 GROCON INCORPORATED GEOTECHNICAL ENVIRONMENTAL MATERIALSO Project No. G September 3, 2014 Nasland Engineering 4740 Ruffner Street San Diego, California Attention: Subject: Mr. Pete Ritchey SUMMARY OF SOIL CONDITIONS CITYWIDE SIDEWALK IMPROVEMENT PROJECT JIMMY DURANTE BOULEVARD, VIA DE LA VALLE, AND CAMINO DEL MAR DEL MAR, CALIFORNIA Dear Mr. Ritchey: In accordance with your request, we have prepared this summary of soil conditions for the proposed sidewalk improvement project planned for City of Del Mar. In preparing this letter we have reviewed the following plans: Project 2, Jimmy Durante Blvd & Camino Del Mar Sidewalk Improvement Project, City of Del Mar, prepared by Nasland Engineering, undated. Project 4, Citywide Sidewalk Improvement Project, Camino Del Mar, City of Del Mar, prepared by Nasland Engineering, undated. Project 5, Citywide Sidewalk Improvement Project, Camino Del Mar, City of Del Mar, prepared by Nasland Engineering, undated. Project 6, Citywide Sidewalk Improvement Project, Via De La Valle, City of Del Mar, prepared by Nasland Engineering, undated. Project 7, Citywide Sidewalk Improvement Project, Jimmy Durante Boulevard, City of Del Mar, prepared by Nasland Engineering, undated. Project 8, Citywide Sidewalk Improvement Project, Camino Del Mar, City of Del Mar, prepared by Nasland Engineering, undated. City of Del Mar, Citywide Sidewalk RFP, prepared by RBF Consulting, dated October 29, 2013, revised November 6, Flanders Drive San Diego, California Telephone Fax

3 We understand our summary is to include project segments 2, 4, 5, 6, 7 and 8. The vicinity map attached as Figure 1, presents the approximate location of the project site. Review of the USGS Geologic Map, Del Mar Quadrangle and in-house geotechnical reports indicates that the site (Segments 2, 4, 5, 6, 7, and 8) are underlain by four surficial deposits and one geologic formation. The surficial deposits consist of Artificial Fill, Paralic Estuary Deposits, Young Alluvium, and Old Terrace Deposits. The formational soil includes Torrey Sandstone. A general description of each of these soil types is provided below. The approximate location of each segment and mapped geologic conditions is presented on the Geologic Map, Figure 2. The referenced November 6, 2013 plan was used as the base map for Figure 2. Artificial Fill (Af) SOIL AND GEOLOGIC CONDITIONS Artificial fill has been mapped at the south end of Segment 5. Local areas of fill that have not been mapped likely exist in other project segments. We expect the fill is comprised of silty to clayey sand and should be suitable for support of sidewalk improvements. Where loose fills are present, shallow remedial grading consisting of removal and recompaction may be required to provide suitable support for new improvements. Paralic Estuary Deposits (Qpe) Paralic Estuary Deposits are mapped near the transition between Segments 2 and 7. The Estuary Deposits are associated with the San Dieguito River. We expect these deposits to consist predominately of clayey sands. Where encountered, remedial removal and recompaction of the upper portion may be required to provide suitable support for new improvements. Young Alluvium (Qya) Young Alluvium is mapped along Segment 6. These soils typically consist of silty to clayey sands. However, considering the proximity of the proposed improvements to existing Via De La Valle, we expect areas of compacted fill are likely present near the proposed improvement area and remedial grading will likely be limited to areas outside of existing roadway improvements. Old Terrace Deposits (Qop) Old terrace deposits are mapped along portions of Segments 4 and 5. The old terrace deposits typically consist of medium dense to very dense sand and silty to clayey sand. This soil typically possesses low expansion and low compressibility characteristics and is suitable for support of additional fill and sidewalk improvements. Torrey Sandstone (Tt) Torrey Sandstone is mapped within or near Segments 2, 4 and 5. The Torrey Sandstone is generally composed of silty to clayey sands that are dense to very dense and have low expansion and low compressibility characteristics. The Torrey Sandstone, where encountered, is suitable for support of additional fill and proposed sidewalk improvements. Project No. G September 3, 2014

4 SUMMARY OF SOIL CONDITIONS AT EACH PROJECT SEGMENT Provided hereafter is a summary of soil conditions within each project segment. SEGMENT 2 Soil Conditions: East side of Jimmy Durante Boulevard from the southern margin of the San Dieguito River to the intersection with Camino del Mar, and along the east side of Camino del Mar to near Plaza Parking. Paralic Estuary Deposits (Qpe). Clayey sands of the Paralic Estuary Deposits are mapped from the southern margin of the San Dieguito River to San Dieguito Drive. Torrey Sandstone (Tt). Silty sands of the Torrey Sandstone are mapped from San Dieguito Drive to 15 th Street. SEGMENT 4 Soil Conditions: Along the north side of Camino Del Mar from near Del Mar Heights Road to 8 th Street. Torrey Sandstone (Tt). Silty sands of the Torrey Sandstone are mapped along the east side of Camino Del Mar. SEGMENT 5 Soil Conditions: Along the west side of Camino Del Mar from Carmel Valley Road to Del Mar Heights Road. Artificial Fill (Af). Artificial Fill likely composed of silty to clayey sand is mapped from the intersection of Carmel Valley Road and extends north to approximately 250 feet. Torrey Sandstone (Tt). Silty sands of the Torrey Sandstone are mapped near the south and north sides of the segment. Old Terrace Deposits (Qop). Clayey to silty sands within the Old Terrace Deposits are mapped generally in the middle portion of the segment. Fault Trace. An inactive fault trace is mapped crossing Camino del Mar at approximately 700 feet north of Carmel Valley Road. Project No. G September 3, 2014

5 SEGMENT 6 Geologic Conditions: South side of Via De La Valle from Camino Del Mar to Jimmy Durante Boulevard. Young Alluvial Deposits (Qya). Silty to clayey sands of Young Alluvial Deposits are mapped along Segment 6. We expect local areas of artificial fill, not mapped, are likely present. SEGMENT 7 Geologic Conditions: Portions of both sides of Jimmy Durante Boulevard from near the intersection of Via De La Valle to near the Del Mar Fire Station. Young Alluvial Deposits (Qya). Silty to clayey sands of Young Alluvial Deposits are mapped from near Via De La Valle to north of the Crosby Gate. We also expect areas of artificial fill exist along this segment that is not mapped. Paralic Estuary Deposits (Qpe). Clayey to silty, sands of the Paralic Estuary Deposits are mapped from the north of the Crosby Gate to northern margin of the San Dieguito River. SEGMENT 8 Geologic Conditions: North side of Camino Del Mar from near Via De La Valle to the bridge at the San Dieguito River. Young Alluvial Deposits (Qya). Silty to clayey sands of the Young Alluvial Deposits are mapped along the alignment. We expect local areas of artificial fill (unmapped) also exists within the segment. In general, the areas proposed to receive the proposed improvements are likely underlain by silty to clayey sands that have low expansion characteristics. Where native Old Terrace Deposits or Torrey Sandstone is encountered, we expect the native soils should be suitable for support of the proposed improvements. In areas where Young Alluvial Deposits, Estuarine Deposits, or loose fills are present, remedial grading may be required. We expect remedial grading to be limited to the upper 2 to 3 feet below proposed improvements. In areas where properly compacted fill exists, only scarifying and recompacting the surface soils are expected. Where proposed improvements cross existing landscaped areas, we expect removals of the upper approximately 1 to 2 feet of soil will likely be required to provide suitable support for proposed improvements. This summary is based on review of available data and our experience in the Del Mar area, however, a geotechnical investigation for each segment should be performed to provide grading recommendations for support of proposed improvements. Project No. G September 3, 2014

6 Should you have questions regarding this report, or if we may be of further service, please contact the undersigned at your convenience. Very truly yours, GEOCON INCORPORATED Rodney C. Mikesell GE 2533 RCM:dmc (2) Addressee Project No. G September 3, 2014

Converse Consultants Geotechnical Engineering, Environmental & Groundwater Science, Inspection & Testing Services

Converse Consultants Geotechnical Engineering, Environmental & Groundwater Science, Inspection & Testing Services Ms. Rebecca Mitchell Mt. San Antonio College Facilities Planning & Management 1100 North