Vista City Council
August 23, 2022

6.0 Area Detail

6.1 Mitigation Measures Area
ROG I NOx I CO S02 Fugitive Exhaust PM10 Fugitive Exhaust PM2.5 Bio-CO2 NBio-CO2 Total CO2 CH4 N20 CO2e PM10 PM10 Total PM2.5 PM2.5 Total Category lb/day lb/day
Mitigated •i 1.3409 i 0.0142 i 1.2364 7.000Oe- 6.8600e- 6.8600e- i i 6.8600e- 6.8600e- 0.0000 i 2.2283 2.2283 i 2.1300e- 0.0000 2.2816 005 003 i 003 003 003 ; 003
Unmitigated 1.3409 0.0142 1.2364 7.000Oe- - 6.8600e- 6.8600e- 6.8600e- 6.8600e- 0.0000 2.2283 2.2283 - 2.1300e- - 0.0000 2.2816 005 003 003 003 003 003

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EMFAC Off-Model Adjustment Factors for Gasoline Light Duty Vehicle to Account for the SAFE Vehicle Rule Applied

6.2 Area by SubCategory
Unmitigated
ROG NOx CO S02 Fugitive Exhaust PM10 I Fugitive Exhaust PM2.5 Bio-CO2 NBio-CO2 Total CO2 CH4 N20 CO2e PM10 PM10 Total PM2.5 PM2.5 Total Subcategory lb/day lb/clay
Architectural •i 0.3729 0.0000 i 0.0000 0.0000 0.0000 0.0000 0.0000 Coating
Consumer •i 0.9309 i � i i � 0.0000 i 0.0000 � i 0.0000 0.0000 � i � 0.0000 i � � 0.0000 Products '� i
Hearth 0.0000 i 0.0000 0.0000 i 0.0000 0.0000 i 0.0000 0.0000 0.0000 0.0000 i 0.0000 0.0000 i 0.0000 0.0000 0.0000 Landscaping •i 0.0371 i 0.0142 1.2364 i 7.0000e- 6.8600e- i 6.8600e- 6.8600e- 6.8600e- 2.2283 2.2283 i 2.1300e- 2.2816 Z 005 003 003 003 003 003 i Total 1.3409 0.0142 1.2364 7.000Oe- 6.8600e- 6.8600e- 6.8600e- 6.8600e- 0.0000 2.2283 2.2283 2.1300e- 0.0000 2.2816 005 003 003 003 003 003

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EMFAC Off-Model Adjustment Factors for Gasoline Light Duty Vehicle to Account for the SAFE Vehicle Rule Applied

6.2 Area by SubCategory
Mitigated
ROG NOx CO S02 Fugitive Exhaust PM10 I Fugitive Exhaust PM2.5 Bio-CO2 NBio-CO2 Total CO2 CH4 N20 CO2e PM10 PM10 Total PM2.5 PM2.5 Total Subcategory lb/day lb/clay
Architectural •i 0.3729 0.0000 i 0.0000 0.0000 0.0000 0.0000 0.0000 Coating
Consumer :1 0.9309 0.0000 i 0.0000 0.0000 0.0000 � i � 0.0000 0.0000 Products i
Hearth •i 0.0000 i 0.0000 0.0000 i 0.0000 0.0000 i 0.0000 0.0000 0.0000 0.0000 i 0.0000 0.0000 i 0.0000 0.0000 0.0000 Landscaping •i 0.0371 i 0.0142 1.2364 i 7.0000e- 6.8600e- i 6.8600e- 6.8600e- 6.8600e- 2.2283 2.2283 i 2.1300e- 2.2816 Z 005 003 003 003 003 003 i Total 1.3409 0.0142 1.2364 7.000Oe- 6.8600e- 6.8600e- 6.8600e- 6.8600e- 0.0000 2.2283 2.2283 2.1300e- 0.0000 2.2816 005 003 003 003 003 003

7.0 Water Detail

7.1 Mitigation Measures Water

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EMFAC Off-Model Adjustment Factors for Gasoline Light Duty Vehicle to Account for the SAFE Vehicle Rule Applied

8.0 Waste Detail

8.1 Mitigation Measures Waste

9.0 Operational Offroad
Equipment Type Number Hours/Day Days/Year Horse Power Load Factor Fuel Type

10.0 Stationary Equipment
Fire Pumps and Emergency Generators
Equipment Type Number Hours/Day Hours/Year Horse Power Load Factor Fuel Type Boilers
Equipment Type Number Heat Input/Day Heat Input/Year Boiler Rating Fuel Type User Defined Equipment
Equipment Type Number

11.0 Vegetation

HELIX Environmental Planning,Inc.
7578 El Cajon Boulevard
La Mesa,CA 91942
619.462.1515 tel HELIX
619.462.0552 fax
www.helixepi.com Environmental Planning
October 27, 2021 04512.00021.001
Ms. Leslea Meyerhoff
Summit Environmental Group, Inc.
2810 Cazadero Drive
Carlsbad, CA 92009
Subject: Biological Resources Letter Report for the 1205 Melrose Way Project Dear Ms. Meyerhoff:

This letter report presents the results of a biological resources technical study conducted by HELIX Environmental Planning, Inc. (HELIX)for the proposed 1205 Melrose Way project(project) located at Assessor's Parcel Number(APN) 166-184-10 in the City of Vista (City), San Diego County, California.This letter report summarizes the existing biological resources within the site and provides an analysis of the proposed project's impacts in accordance with the California Environmental Quality Act (CEQA) and other applicable federal, state, and local policies related to biological resources.The City would be the Lead Agency for the project responsible for conducting the environmental review process under CEQA as well as ensuring the project is consistent with pertinent federal/state laws and local ordinances.

INTRODUCTION
Project Location
The approximately 2.6-acre project site is located in the City of Vista, in San Diego County, California (Figure 1, Regional Location).The site is located on Section 25,Township 11 South, Range 4 West on the U.S. Geological Survey(USGS) 7.5-minute San Luis Rey quadrangle map (Figure 2, USGS Topography).

Specifically,the site is immediately north of Melrose Way,west of South Melrose Drive, south of Breeze Hill Road, and east of McGavran Drive (Figure 3,Aerial Photograph of Project Location).

The project site is within the boundaries of the North County Multiple Habitat Conservation Program (MHCP; AMEC Earth & Environmental et al. 2003).The proposed project site is recognized within the Vista Subarea of the MHCP, which does not have an approved or adopted subarea plan under the MHCP. Because the City does not have an adopted subarea plan the project would not require compliance to the MHCP provisions; thus,the MHCP is not discussed in detail further in this report.

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Project Description
The project proposes the demolition of the existing residence on the property as well as mass grading to construct 15 new, detached, single-family residences.This 15-lot subdivision would include a new private street, a private driveway, a biofiltration basin, and associated hardscape. In addition to the subject property, the project site includes an off-site emergency access road and additional grading to the northwest as well as infrastructure connections/improvements to the south along the interface with Melrose Way(Figure 4, Project Site Plan).

METHODS
Literature Review
Prior to conducting the field survey, searches through applicable databases, such as but not limited to the California Department of Fish and Wildlife (CDFW) California Natural Diversity Database (CNDDB), California Native Plant Society(CNPS) online database, and the U.S. Fish and Wildlife Service (USFWS) sensitive species occurrences database were conducted for information regarding sensitive species known to occur or documented present within the project site and surrounding vicinity.

General Biological Survey
A general biological survey was conducted by HELIX biologist Dane van Tamelen on September 9, 2021.

The survey study area comprised of the project property and a 100-foot surrounding buffer, which was surveyed on foot and with the aid of binoculars.The survey included mapping of vegetation communities, habitat assessments for special status species, and identification of other sensitive biological resources that occur or have potential to occur in the study area.Vegetation was mapped on a 1-inch equals 150 feet scale map with a 2019 aerial photograph base. Animal identifications were made in the field by direct,visual observation, or indirectly by detection of calls, burrows, tracks, or scat. Plant identifications were made in the field or in the lab through comparison with voucher specimens or photographs. Plants and animals observed or detected during the survey were recorded (Attachments A and B, respectively).These lists of species identified are not necessarily comprehensive accounts of all species that occur in the study area, as species that are nocturnal, secretive, or seasonally restricted may not have been observed.

Focused surveys for rare plants and sensitive animal species were not conducted as part of the general survey; none were required to inform the technical study. A formal jurisdictional delineation was also not conducted; however,the survey included searching and preliminary mapping of aquatic features in the study area that could be potentially subject to the U.S. Army Corps of Engineers (USACE)jurisdiction pursuant to Section 404 of the Clean Water Act (33 USC 1344), Regional Water Quality Control Board (RWQCB)jurisdiction pursuant to Section 401 of the Clean Water Act or the Porter Cologne Water Quality Control Act, or CDFW jurisdiction pursuant to Section 1600 of the California Fish and Game (CFG) Code.

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Nomenclature
Nomenclature used in this report comes from Holland (1986) and Oberbauer(2008)for vegetation communities; Baldwin et al (2012)for plants; the American Ornithologists' Union (2012) for birds; and Baker et al. (2003) for mammals. Plant species status is taken from the CNPS (2021).

ENVIRONMENTAL SETTING
Regional Context
The project site is within the boundaries of the MHCP, specifically the Vista Subarea, and occurs outside any lands targeted for conservation.

General Land Uses
The site is mostly undeveloped land except for an existing single-family residence in the southwest portion of the property. Although mostly undeveloped,the property character is disturbed, and no natural vegetation was observed. Non-native and ornamental species are the dominant plants found in the study area. Disturbances on-site includes evidence of regular mowing of the undeveloped/weedy areas.Additionally, based on a review of historical aerial imagery,the site has been used and an orchard (likely citrus) since the early 1930s and the dwelling on-site was constructed sometime between 1953 and 1964(Historical Aerials 2021). Existing residential properties and development (commercial, residential, and a church) surround the proposed project study area (Figure 3). Nearest transportation corridors include State Route (SR) 78 located approximately 0.5 mile north of the project and S. Melrose Drive approximately 0.2 mile east of the project.

Topography and Soils
Elevations on the project site range from approximately 353 feet above mean sea level (amsl) in the eastern corner of the property up to 373 feet amsl in the southwest corner of the site.Topography in on-site is generally flat (less than 10 percent slopes)terrain that gently slopes down from south to north.

Two soil types are mapped within the site: Placentia sandy loam, five to nine percent slopes, eroded; and Bosanko clay, nine to 15 percent slopes (Figure 5,Soils) (U.S. Department of Agriculture 2021).

RESULTS
Vegetation Communities
The project site supports two vegetation communities/habitats: disturbed habitat and developed land (Figure 6, Vegetation Communities;Table 1, Existing Vegetation Communities).

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Table 1
EXISTING VEGETATION COMMUNITIES"
Vegetation CommunityZ Project SiteOn-Site' Off-Site Total Disturbed Habitat(11300) 2.0 0.1 2.1
Developed Land (12000) 0.6 0.1 0.7
TOTAL 2.6 0.2 2.8
" Acreages rounded to the nearest 0.1 acre.
z Vegetation community classifications and numerical codes from Holland(1986)and Oberbauer(2008). 3 Subject property,APN 166-184-10.

Disturbed Habitat
Disturbed habitat includes land cleared of vegetation (e.g., dirt roads), land containing a preponderance of non-native plant species such as ornamentals or ruderal exotic species that take advantage of disturbance (previously cleared or abandoned landscaping), or land showing signs of past or present animal usage that removes any capability of providing viable habitat. Within the project site, disturbed habitat consists of bare ground and undeveloped areas that predominantly support non-native plant species such as: Russian thistle (Salsola tragus), black mustard (Brassica nigra), and non-native grasses.

Developed Land
Developed land includes areas that have been constructed upon or otherwise covered with a permanent, unnatural surface and may include, for example, structures, pavement, irrigated landscaping, or hardscape to the extent that no natural land is evident. These areas no longer support native or naturalized vegetation (Oberbauer 2008). Developed land occurs mapped for the project site includes an existing single-family residence and associated areas, ornamental landscaping, and paved/ concrete areas of the site.

Plants
A total of 14 plant species were observed within the project site during the general biological survey, of which 12 species are non-native (Attachment A).

Animals
A total of nine animal species, including eight bird and one mammal species, were observed or detected within the project site during the general biological survey (Attachment B).

Sensitive Biological Resources
Sensitive Vegetation Communities
Sensitive vegetation communities are those considered rare within the local region or sensitive by CDFW; are listed as sensitive under a regional planning program (MHCP for example); support sensitive plants or animals, and as defined by Section 15380 of the State CEQA Guidelines.They are considered sensitive because they have been depleted, are naturally uncommon, or support sensitive species.

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No sensitive vegetation communities were observed on-site during the field survey.

Sensitive Plants
Special status plant species have been afforded special status and/or recognition by the USFWS and/or CDFW.They also include species listed in the CNPS' Inventory of Rare and Endangered Plants. Rare plant status is often based on one or more of three distributional attributes: geographic range, habitat specificity, and/or population size. No sensitive plant species observed on the project site.

Searches of the CNDDB and CNPS online databases for within one mile of the site revealed records of one sensitive plant species recorded and located approximately 0.3 mile southeast of the project site:
thread-leaved brodiaea (Brodiaea filifolia)(Appendix C).This species is federally listed threatened, state listed endangered, CNPS Rare Plant Rank 113.1, and is considered a Narrow Endemic per the MHCP.

Thread-leaved brodiaea is often associated with valley grasslands,vernal pool habitats,foothill woodlands, coastal sage scrub and chaparral; often found in clay soils. Clay soils are mapped in the southwest corner of the site; however, the site does not support vernal pools, grasslands, or other suitable habitats for this species. Because of the high level of historical and current disturbances of the site,thread-leaved brodiaea is not expected to occur. Based on the disturbed site conditions and lack of natural/suitable habitat, no other sensitive plant species are expected to occur or have potential to occur on-site.

Sensitive Animals
No sensitive animal species were observed or detected within the project site during biological surveys, and no federal or state listed species are expected to occur on-site.The site does support marginally suitable nesting habitat for raptors in the area such as Cooper's hawk(Accipiter cooperii), which could use the non-native trees on-site for nesting. However, no raptors or raptor nests were detected on-site during the survey.

Based on searches through CNDDB, USFWS, and other databases for within two miles of the project site, the nearest record is of one sensitive animal species located approximately one mile northeast of the project site: California black rail (Laterallus jamaicensis coturniculus) (Appendix D).This species is state listed threatened, a CDFW Fully Protected species, and a USFWS Bird of Conservation Concern. Based on the lack of wetland and aquatic habitats required for this species, California black rail is not expected to occur on-site. Additionally, no other sensitive animal species are expected to occur or have potential to occur on-site based on the existing disturbances, absence of native vegetation/habitat, and lack of site connectivity to larger natural open space (habitat) areas.

Jurisdictional Waters and Wetlands
No potentially jurisdictional resources were observed on-site during the survey.The project site is entirely uplands. No aquatic features (e.g., drainages, ponds/pools, riparian, or wetland vegetation) were found on-site.

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Wildlife Corridors and Movement
Wildlife corridors connect otherwise isolated pieces of habitat and allow movement or dispersal of plants and animals. Wildlife corridors can be local or regional in scale.Their functions may vary temporally and spatially based on conditions and species presence. Corridors represent areas where wildlife movement is concentrated due to natural or anthropogenic constraints. Local corridors provide access to resources such as food, water, and shelter. Animals use these corridors in daily routine to move between different habitats. Regional corridors also provide these functions and link two or more large habitat areas providing avenues for wildlife dispersal, migration, and contact between otherwise distinct populations.

The project site does not function as or contribute to a local or regional wildlife corridor. The site is relatively small, does not support native habitat, and is bounded on all sides by urban development.The project site does not provide connectivity to larger contiguous open space areas beyond the site.

REGIONAL AND REGULATORY CONTEXT
The following federal, state, and/or local regulations apply to biological resources on-site.

Federal
Migratory Bird Treaty Act
All migratory bird species native to the United States and its territories are protected under the Migratory Bird Treaty Act (MBTA), as amended.The MBTA mandates protection for eggs and chicks of all migratory bird species but does not stipulate specific protection measures. In common practice,the MBTA is used to place restrictions on disturbance of active bird nests during the nesting season (generally February 1 to August 31). In addition,the USFWS commonly places restrictions on disturbances allowed near active raptor nests.

State of California
California Environmental Quality Act
Primary environmental legislation in California is found in CEQA and its implementing guidelines (State CEQA Guidelines), requiring that projects with potential adverse effects or impacts to the environment undergo environmental review. Adverse impacts to the environment are typically mitigated as a result of the environmental review process in accordance with existing laws and regulations.

California Fish and Game Code
Pursuant to California Fish and Game Code Section 3503, it is unlawful to take, possess, or needlessly destroy the nest or eggs of any bird, except as otherwise provided by this code or any regulation made pursuant thereto. Raptors and owls and their active nests are protected by California Fish and Game Code Section 3503.5,which states that it is unlawful to take, possess, or destroy any birds of prey or to take, possess, or destroy the nest or eggs of any such bird unless authorized by the CDFW.

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Natural Communities Conservation Planning Act
The Natural Communities Conservation Planning(NCCP) program is a cooperative effort to protect habitats and species. It began under the State's NCCP Act of 1991, legislation broader in its orientation and objectives than the CESA or FESA.These laws are designed to identify and protect individual species that have already declined significantly in number.The NCCP Act of 1991 and the associated Southern California Coastal Sage Scrub NCCP Process Guidelines (1993), Southern California Coastal Sage Scrub NCCP Conservation Guidelines (1993), and NCCP General Process Guidelines(1998) have been superseded by the NCCP Act of 2003.The MHCP is an enrolled NCCP program and was adopted in 2003 by the County.

City of Vista
General Plan
The Resource Conservation and Sustainability (RCS) Element of the City's General Plan 2030 (City 2011) provides the following RCS goals and policies applicable to the project site as they relate to conservation of natural resources as well as protection and preservation of sensitive species and their habitats.

RCS Goal 5: Preserve and protect,to the extent practicable,the range of natural biological communities and species native to the City and region; and conserve viable populations of endangered,threatened, and key sensitive species and their habitats.
• RCS Policy 5.1: Continue to require development that is proposed in areas identified or expected to contain sensitive vegetation and wildlife communities to consult with wildlife agencies (i.e., USFWS and CDFG) early in the development review process regarding special status plant and wildlife species; conduct biological assessments, as appropriate; and develop and implement project-specific mitigation measures to mitigate impacts on threatened and endangered species.
• RCS Policy 5.2: In areas that are adjacent to sensitive vegetation and/or wildlife communities, continue to require development, uses, and activities to be designed and managed to ensure minimal impacts to those resources. Examples include but are not limited to the following:
a. Provide buffers or barriers between the development and the biological resources.

Buffers from the edge of the existing natural tree canopy should be established based on scientific analysis of the existing site conditions and the development proposal by a qualified biologist. New buildings or parking areas should not be permitted within any buffer area.
b. Prohibit parking lots and other developed areas from draining into sensitive resources. c. Require land uses that use chemicals or fertilizers or generate by- products that are potentially toxic or harmful to wildlife, sensitive species, and habitats to incorporate measures to mitigate those impacts.

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d. Require development to incorporate measures that avoid degradation of habitats from erosion and sedimentation.
e. Ensure that sensitive species are protected from night lighting from nearby development.
f. Mitigate noise impacts from development, uses, or activities on nearby sensitive species through noise reduction measures and/or restriction of hours during the breeding season of sensitive species.
g. Require development that is adjacent to sensitive resources to landscape their sites with native, non - invasive vegetation that is similar to or compatible with the adjacent resources and prohibit horticultural regimes (irrigation, fertilization, pest control, and pruning) that could alter site conditions in natural areas. h. Enforce fire and brush management plans so that both biological and safety goals are met.
• RCS Policy 5.3: Preserve the integrity of riparian habitat areas, creek corridors, and other drainages that support biological resources and contribute to the overall health of the watershed areas through the preservation and restoration of native plants and the removal of invasive, exotic, and nonnative species.
• RCS Policy 5.4: Preserve, protect, and enhance the City' s urban forest (on both public and private property).
• RCS Policy 5.5: Consider adoption of a tree preservation ordinance to address tree preservation on private property.
• RCS Policy 5. 6: Continue to require the use of native, naturalized, and non-invasive plants and turf to avoid or minimize use of irrigation, fertilizers, and pesticides, and to provide increased wildlife habitats for native species.
• RCS Policy 5.7:To the extent practicable, and as determined by the City, avoid sensitive habitats and species during the planning, design, and construction of new public infrastructure (such as sewers, storm drain and flood control facilities, utilities, and roads), unless alternative locations are not practical.
• RCS Policy 5.8: Maintain and regularly update a database of biological resource information relevant to natural resources in Vista, including regional data sets and more focused field investigations within the City.

RCS Goal 6: Implement the provisions of the regional Multiple Habitat Conservation Plan (MHCP). • RCS Policy 6.1: Establish and maintain a Biological Preserve Overlay(BPO) reflecting the Focused Planning Area (FPA) in the MHCP to the maximum extent practicable.The BPO shall define lands HELIX
Environmental Planning

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worthy of protection based on the presence of sensitive vegetation and wildlife communities, orthose lands that support viable wildlife corridors.
• RCS Policy 6.2: Limit land uses within the BPO to only those necessary for the protection of public health and safety, or recreational uses that are consistent with the conservation standards in the MHCP. Biological conservation shall be the primary objective within the BPO whenever potential conflicts with recreational uses arise. • RCS Policy 6.3: Establish maintenance and management standards for the BPO to ensure permanent conservation.The City's standards shall be based on the applicable standards in Section 6.0 of the Final MHCP (Fire Management; Habitat Restoration; Erosion Control; Landscaping Restrictions; Recreation and Public Access; Fencing, Signs and Lighting; Predator and Exotic Species Control; Hydrology and Flood Control; and Species Reintroduction), subject to the availability of permanent funding.
• RCS Policy 6.4: Adopt a Habitat Conservation Plan (i.e., a Subarea Plan) covering, at minimum, the BPO and enter into an Implementing Agreement with the Wildlife Agencies, subject to the availability of permanent funding.
• RCS Policy 6.5: Use the mitigation ratios established in the MHCP for impacts to sensitive biological habitats.
• RCS Policy 6.6: Integrate the City's conservation planning efforts with watershed planning, GHG reductions, and other regional planning efforts involving natural resources when possible in order to maximize opportunities for grant funding for conservation purposes.

RCS Goal 7: Conserve, enhance, and restore,to the extent practicable, open space areas for the protection of wildlife habitats and plant and animal species. • RCS Policy 7.1: Acquire or otherwise protect, where possible, open space and other properties that contain or protect significant sensitive resources,such as special-status plant and wildlife species know to occur in or near the City, natural habitats, and habitat linkages. Primary consideration shall be given to those properties within the City's BPO. Actions may include but are not limited to:
a. Acquire private land with significant natural habitat or sensitive resources, assuming the seller is willing and that funding is available.
b. Encourage the County, state, and federal government, or other conservation agency dedicated to the City's conservation goals,to acquire private land with significant natural habitat or sensitive resources, assuming the seller is willing. c. Enforce state and federal conservation and avoidance regulations,through the development review process,for all new development projects on private property that may potentially impact affect natural vegetation communities or biological resources within the City.

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d. Acquire easement rights or establish agreements with public utilities to ensure the protection of natural habitats or sensitive resources within existing or planned utility easements.
e. Require privately owned open space designed as an integral part of a new development to be designated Open Space (OS) on the Land Use Map.
• RCS Policy 7.2: Cooperate with other municipalities and the County to strive to acquire or otherwise protect open space areas that provide key habitat linkages and wildlife movement corridors on a regional level.

Multiple Habitat Conservation Program
The City is part of the MHCP,which is a comprehensive, multiple jurisdictional planning program to address sensitive species and develop an ecosystem preserve in northwestern San Diego County.

Implementation of the MHCP regional preserve system is intended to protect viable populations of key sensitive plant and animal species and their habitats,while accommodating continued economic development and quality of life for residents of north county(AMEC 2003).The City is required to develop a subarea plan in order to obtain take authorizations provided by the MHCP.The City is collaborating with other north county jurisdictions and is in the process of preparing a subarea plan (City 2011).Thus, guidance contained within the MHCP is advisory, but is considered for regional context by the City and is implemented through the General Plan as discussed above.

PROJECT EFFECTS AND PROPOSED MITIGATION MEASURES
For the purpose of evaluating potential project effects and as prescribed by the Issues in CEQA Appendix G Section IV Biological Resources,the proposed project would result in a significant impact if it would:

1. Have a substantial adverse effect, either directly or through habitat modifications, on any candidate, sensitive, or special status species in local or regional plans, policies, or regulations or by the USFWS or CDFW;

2. Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, or regulations, or by USFWS or CDFW;

3. Have a substantial adverse effect on federally protected wetlands as defined by Clean Water Act Section 404;

4. Interfere substantially with movement of any native resident, migratory fish, or wildlife species, or established native resident or migratory wildlife corridors; or impede use of native wildlife nursery sites;

5. Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance; or

6. Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state conservation plan.

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IMPACTS
This section describes potential direct and indirect affects (impacts) on biological resources associated with the proposed project. Direct impacts are immediate impacts and typically result in permanent removal. Direct impacts for the project were quantified by overlaying the limits of project-related ground disturbance on the biological resources map of the site (Figure 7, Project Impacts). Indirect impacts are actions that are not direct removal of resources but affect the surrounding resources either as a secondary effect of the direct impacts (e.g., construction noise, runoff, nighttime lighting, fugitive dust, etc.) or as the cause of degradation of a biological resource over time (e.g., edge/adjacency effects).The magnitude of an indirect impact can be the same as a direct impact; however, the effect usually takes a longer time to become apparent.

Issue 1 — Sensitive Species
Would the project have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the CDFW or USFWS?
Issue 1 Analysis of Project Effects
Less than Significant Impact with Mitigation. Potential impacts to special status plants and animals are not expected. Because the project site contains trees, shrubs, and other vegetation that provide suitable nesting habitat for common birds, including raptors, protected under the MBTA and CFG Code the project could result in adverse impacts (both direct and/or indirect)to nesting if project activities such as demolition, clearing, grubbing, or grading are implemented during the general nest season (January 15 to September 15) and nesting is found in the area. Impacts to nesting birds, including raptors,would be a violation of the MBTA and CFG Code and are considered significant. Potential impacts to nesting birds and raptors would be avoided or reduced to less than significant levels through implementation of mitigation measure 1131O-1.

Issue 1 Mitigation Measures
113I0-1 Pre-Construction Surveys for Avian Nesting. Project construction activities (demolition, grading, clearing, grubbing) shall be conducted between September 16 and January 31, which is outside of the nesting season for birds and raptors. If initial grading and vegetation removal activities (i.e., earthwork, clearing, and grubbing) must occur during the general bird nesting season (January 15 to September 15),the project applicant shall retain a qualified biologist to conduct a pre-construction survey for nesting birds and raptors.The survey shall be completed no more than three days prior to the beginning of demolition or other construction impacts. If the survey concludes no active bird or raptor nesting,then project activities shall be allowed to proceed without any further requirements. If active bird nests are confirmed to be present during the pre-construction survey,then a buffer zone shall be established by the biologist. Construction activities shall avoid any active nests until a qualified biologist has verified that the young have fledged, or the nest has otherwise become inactive.

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Issue 2 - Sensitive Natural Communities
Would the project have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, and regulations or by the CDFW or USFWS? Issue 2 Analysis of Project Effects
No Impact.The proposed project would not have any direct or indirect impacts to sensitive vegetation communities. No sensitive natural communities occur or adjacent to the project site. Project impacts would encompass disturbed habitat and developed land only, neither of which are considered sensitive or require mitigation (Figure 7).

Issue 2 Mitigation Measures
No mitigation required.

Issue 3 - Wetlands
Would the project have a substantial adverse effect on federally-protected wetlands as defined by Section 404 of the federal Clean Water Act(including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal,filling, hydrological interruption, or other means? Issue 3 Analysis of Project Effects
No impact.The project site is entirely upland.There are no wetlands or other potentially jurisdictional aquatic resources on-site or adjacent to the site (Figure 7). No federally protected wetlands or other jurisdictional resources occur within or adjacent to the project site.

Issue 3 Mitigation Measures
No mitigation required.

Issue 4 - Wildlife Movement and Nursery Sites
Would the project interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites?
Issue 4 Analysis of Project Effects
No Impact.The project site is entirely uplands and does not support aquatic resources to support fish.

The uplands on-site are classified as developed and disturbed, which do not reflect suitable habitat for wildlife or nursery sites. Because the project site is urban, is surrounded by existing development, and there is no connectivity with natural habitats beyond the site,the project would not interfere with any corridors for local wildlife movement.

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Biological Resources Letter Report for the 1205 Melrose Way Project Page 13 of 15 October 27, 2021
Issue 4 Mitigation Measures
No mitigation is required.

Issue 5 - Local Policies and Ordinances
Would the project conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance?
Issue 5 Analysis of Project Effects
No impact.The City does not have a tree preservation policy or other ordinance for the protection of biological resources.The City's adopted General Plan does outline policies for protecting and preserving biological resources in the City; however, because there are no native vegetation communities, natural biological resources, or sensitive species on-site,the project would result in no impact to biological resources and would not conflict with the City's General Plan in this regard.

Issue 5 Mitigation Measures
No mitigation is required.

Issue 6 - Adopted Conservation Plans
Would the project conflict with the provisions of an adopted Habitat Conservation Plan, Natural Conservation Community Plan, or other approved local, regional, or state habitat conservation plan? Issue 6 Analysis of Project Effects
No Impact.The project would not conflict with an adopted NCCP or other adopted Conservation Plan.

The project does occur within the boundaries of the North County MHCP, particularly in the Vista Subarea, which has not yet been approved or adopted. Because implementation of the North County MHCP requires the adoption of individual subarea plans and the Vista subarea plan remains in draft form as of the date of this report,the requirements and guidelines are not applicable to the proposed project.The City's adopted General Plan provides direction and policies per the MHCP for protection and conservation biological resources (see Issue 5 above); however, because no natural biological resources or sensitive species occur on-site, implementation of the proposed project would not conflict with these conservation policies. Implementation of the project would not preclude or prevent finalizing and adoption of the Vista subarea plan.

Issue 6 Mitigation Measures
No mitigation is required.

CONCLUSION
The proposed project would result in less than significant impacts to biological resources, specifically nesting birds/raptors.The timing of project construction and adherence with the mitigation measure listed above, would ensure potential impacts to biological resources are avoided and remain below a HELIX
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Biological Resources Letter Report for the 1205 Melrose Way Project Page 14 of 15 October 27, 2021
level of significance. Please contact me at(619)462-1515 or [email protected] if you have questions or need assistance with project mitigation compliance.

Sincerely,

F -
Thomas Liddicoat
Biology Project Manager/Senior Biologist
Enclosures:

Figure 1 Regional Location
Figure 2 USGS Topography
Figure 3 Aerial Photograph of Project Location
Figure 4 Project Site Plan
Figure 5 Soils
Figure 6 Vegetation Communities
Figure 7 Project Impacts
Attachment A Plant Species Observed
Attachment B Animal Species Observed or Detected
Attachment C Plant Species Potential to Occur
Attachment D Plant Species Potential to Occur
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Biological Resources Letter Report for the 1205 Melrose Way Project Page 15 of 15 October 27, 2021

REFERENCES
AMEC Earth & Environmental (AMEC) and Conservation Biology Institute (CBI). 2003. Final Multiple Habitat Conservation Program (MHCP) Plan. March.

American Ornithologists Union. 2012. American Ornithologists Union Checklist of North American Birds. 7th Edition. Available at: AOS Checklist of North and Middle American Birds (americanornithology.org).

Baker, R.J., L.C. Bradley, R.D. Bradley,J.W. Dragoo, M.D. Engstrom, R.S. Hoffmann, C.A.Jones, F. Reid, D.W. Rice, and C.Jones. 2003. Revised checklist of North American mammals north of Mexico.

Occasional Papers of the Museum,Texas Tech University 223.

Baldwin, B.G., D.H. Goldman, D.J. Keil, R. Patterson,T.J. Rosatti, and D.H. Wilken, editors. 2012.The Jepson Manual: Vascular Plants of California, second edition. University of California Press, Berkeley.

California Native Plant Society(CNPS). 2021. Inventory of Rare and Endangered Plants. Internet searchable database Version 7-10c.Available at: Inventory of Rare and Endangered Plants of California -CNPS. Updated quarterly.

City of Vista (City). 2011. General Plan 2030. December.Available at: Vista General Plan 2030 1 City of Vista, CA
Historical Aerials. 2021.Available at:. https://www.historicaerials.com/viewer .

Holland, R.F. 1986. Preliminary Descriptions of the Terrestrial Natural Communities of California.

Nongame-Heritage Program, California Department of Fish &Game.

Oberbauer,T. 2008.Terrestrial Vegetation Communities in San Diego County Based on Holland's Descriptions. Revised from 1996 and 2005.July.

HELIX
Environmental Planning

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Attachment A
Plant Species Observed

1205 Melrose Way Project
Attachment A
Plant Species Observed
Family Scientific Name* Common Name
Dicots
Anacardiaceae Schinus terebinthifolius* Brazilian pepper tree Arecaceae Woshingtonio robusta* Mexican fan palm
Cynaro cardunculus* artichoke thistle
Asteraceae Heterotheca grandiflora telegraph weed Sonchus oleraceus* common sow thistle
Brassicaceae Brassica nigra* black mustard
Chenopodiaceae Salsola tragus* Russian thistle
Fabaceae Acacia sp.* wattle
Myrtaceae Eucalyptus sp.* eucalyptus
Polygonaceae Rumex crispus* curly dock
Vitaceae Vitis sp. grape
Monocots
Strelitziaceae Strelitzia nicolai* giant bird of paradise Poaceae Bromus hordeaceus* soft chess
Bromus modritensis* foxtail chess
*Non-native Species
A-1

Attachment B
Animal Species Observed or
Detected

1205 Melrose Way Project
Attachment B
Animal Species Observed or Otherwise Detected
Taxon
Order Family Scientific Name Common Name

VERTEBRATES
Birds
Apodiformes Trochilidae Calypte anna Anna's Hummingbird Columbiformes Columbidae Zenaida macroura Mourning Dove Corvidae Corvus brachyrhynchos American Crow
Corvus corax Common Raven
Passeriformes
Emberizidae Melozone crissalis California Towhee Fringillidae Haemorhous mexicanus House Finch
Tyrannidae Sayornis saya Say's Phoebe
Tyrannidae Tyrannus vociferans Cassin's Kingbird Mammals
Rodentia Sciuridae Otospermophilus beecheyi California ground squirrel B-1

Attachment C
Plant Species Potential to Occur

1205 Melrose Way Project
Attachment C
Special Status Plant Species Potential to Occur
Species Status' Habit,Ecology and Life History Potential to Occur Red sand-verbena -/- Perennial herb. Occurs in coastal dunes. Elevation: below Presumed Absent. No suitable habitat (Abronia maritima) CRPR 4.2 328 feet(100 meters). Flowering period: February to present on-site. Plus,this perennial December. species would have been observed
during biological surveys and was not
detected.

Chaparral sand-verbena -/- Annual herb.Grows on desert dunes and in sandy areas Presumed Absent. No suitable habitat (Abronia villosa var.aurita) CRPR 113.1 within coastal scrub,chaparral. Found along the coast from present on-site. Plus,this perennial Ventura County south to San Diego County,and east to San species would have been observed Bernardino, Riverside,and Imperial Counties. Flowering during biological surveys and was not period: March to September. Elevation:245 to 5,250 feet detected. (75 to 1,600 meters).

San Diego thorn-mint FT/CE Annual herb.Typically grows on clay soils within chaparral, Low.Suitable clay soils are present (Acanthomintha ilicifolia) CRPR 16.1 coastal scrub,valley and foothill grassland,and vernal pools. within the project site, however there MHCP Covered Found in San Diego County. Flowering period:April to June. are not suitable habitats for this Elevation: below 30 to 3,150 feet(10 to 960 meters). species as site has been historically altered/disturbed.

Nuttall's lotus -/- Annual herb. Grows on coastal dunes and sandy areas coastal None.Suitable sandy dune habitat is (Acmispon prostratus) CRPR 113.1 scrub in San Diego County. Flowering Period: March to June. absent from the project site,and the MHCP Covered Elevation: below 35 feet(10 meters). site is located above the species known elevation range.

California adolphia -/- Perennial shrub. Most often found in coastal scrub but Presumed Absent. No suitable habitat (Adolphia californica) CRPR 26.1 occasionally occurs in peripheral chaparral habitats, present on-site. Plus,this perennial particularly hillsides near creeks on clay soils. Found in San species would have been observed Diego County. Flowering period: December to May. during biological surveys and was not Elevation: 30 to 2,430 feet(10 to 740 meters). detected.

San Diego ambrosia FE/-- Perennial herb. Occurs on sandy loam or clay,sometimes Presumed Absent. No suitable habitat (Ambrosia pumila) CRPR 16.1 alkaline,soils within grasslands, dry drainages,stream present on-site. Plus,this perennial floodplain terraces, and vernal pool margins.Also occurs on species would have been observed slopes,disturbed places,and in coastal sage scrub or during biological surveys and was not chaparral. Found in Riverside and San Diego Counties. detected.

Flowering period:April to October. Elevation: 65 to
1,360 feet(20 to 415 meters).

C-1

1205 Melrose Way Project
Attachment C (cont.)
Special Status Plant Species Potential to Occur
Species Status' Habit,Ecology and Life History Potential to Occur Aphanisma -/- Annual herb.Occurs on sandy or gravelly soils within coastal Low.Suitable sandy soils are present (Aphanisma blitoides) CRPR 16.2 dunes,coastal bluff scrub,and coastal scrub. Found along the within the project site, however MSCP Covered coast from Santa Barbara County south to San Diego County suitable coastal dune or scrub habitat and the Channel Islands. Flowering period:June to is absent and there are no September. Elevation: below 656 feet(305 meters). documented occurrences within the immediate project vicinity.

Del Mar manzanita FE/-- Perennial shrub. Occurs within relatively open,coastal Presumed Absent. No suitable habitat (Arctostaphylos glandulosa ssp. CRPR 16.1 chaparral and maritime chaparral on sandy soils.At present on-site. Plus,this perennial crassifolia) MHCP Covered occasional inland sites it occurs in denser mixed chaparral species would have been observed vegetation. Found in San Diego County. Flowering Period: during biological surveys and was not December to June. Elevation: below 1,200 feet(365 meters). detected.

San Diego sagewort -/- Perennial herb.Typically found along stream courses,often Presumed Absent. No suitable habitat (Artemisia palmeri) CRPR 4.2 beneath riparian woodland,on sandy and mesic soils. May present on-site. Plus,this perennial occur in coast live oak woodland,coastal sage scrub, and species would have been observed southern mixed chaparral. Found in San Diego County during biological surveys and was not Flowering period:June to October. Elevation: 50 to detected. 3,000 feet(15 to 915 meters).

Coulter's saltbush -/- Perennial herb. Occurs on alkaline or clay soils within coastal Presumed Absent. No suitable habitat (Atriplex coulteri) CRPR 113.2 dunes,coastal bluffs,coastal sage scrub,and grasslands. present on-site. Plus,this perennial Found along the coastal regions from Santa Luis Obispo species would have been observed County south to San Diego County,western portions of San during biological surveys and was not Bernardino and Riverside Counties,and the Channel Islands. detected.

Flowering period: March to October. Elevation: below
1,510 feet(460 meters).

South coast saltscale -/- Annual herb. Found coastally on dunes and within playas in None.Suitable wetland habitat is (Atriplex pacifica) CRPR 16.2 alkali sinks,sage scrub, and wetland riparian communities. absent from the project site.

Found along the coastal regions from Santa Barbara County south to San Diego County,western portions of San
Bernardino and Riverside Counties,and the Channel Islands.

Flowering period: March to October. Elevation: below
460 feet(140 meters).

C-2

1205 Melrose Way Project
Attachment C (cont.)
Special Status Plant Species Potential to Occur
Species Status' Habit,Ecology and Life History Potential to Occur San Diego County viguiera -/- Perennial shrub. Occurs on a variety of soil types within Presumed Absent. No suitable habitat (Bahiopsis laciniata) CRPR 4.3 coastal sage scrub in San Diego County.Generally,shrub present on-site. Plus,this perennial cover is more open than at mesic,coastal locales supporting species would have been observed sage scrub. Found along the coastal regions from Ventura during biological surveys and was not County south to San Diego County and western Riverside detected.

County. Flowering period: February to August. Elevation:295 to 2,461 feet(90 to 750 meters).

San Diego goldenstar -/- Perennial bulbiferous herb. Occurs in valley grasslands and Low.Suitable clay soils are present (Bloomeria clevelandii) CRPR 1B.1 coastal scrub, particularly near mima mound topography or within the project site, however there in the vicinity of vernal pools,on clay soils. Found in Riverside are not suitable habitats for this and San Diego Counties. Flowering period:April to May. species as site has been historically Elevation: 160 to 1,525 feet(50 to 465 meters). altered/disturbed.

Thread-leaved brodiaea FT/SE Perennial herb. Often associated with vernal pools.Also Low.Suitable clay soils are present (Brodiaea filifolia) CRPR 1B.1 occurs within playas,grasslands,coastal scrub, openings in within the project site, however there chaparral,and cismontane woodland;often on clay soils. are not suitable habitats for this Found in Los Angeles, Orange,San Bernardino, Riverside,and species as site has been historically San Diego Counties. Flowering period: March to June. altered/disturbed.

Elevation:80 to 3,675 feet(25 to 1,120 meters).

Orcutt's brodiaea -/- Perennial bulbiferous herb.Occurs within closed-cone Low.Suitable clay soils are present (Brodiaea orcuttii) CRPR 1B.1 coniferous forest,chaparral,cismontane woodland, within the project site, however there meadows and seeps,valley and foothill grassland,and vernal are not suitable habitats for this pools. Prefers mesic or clay soils. Found in Riverside San species as site has been historically Diego Counties. Flowering period: May to July. Elevation:98 altered/disturbed. to 5,550 feet(30 to 1,692 meters).

Wart-stemmed ceanothus -/- Perennial shrub. Found on rocky slopes within chaparral, Presumed Absent. No suitable habitat (Ceanothus verrucosus) CRPR 2B.2 particularly southern maritime chaparral. Found in Riverside present on-site. Plus,this perennial MHCP Covered and San Diego Counties. Flowering period: December to May. species would have been observed Elevation: below 1,245 feet(380 meters). during biological surveys and was not detected.

Smooth tarplant -/- Annual herb. Occurs on alkaline soils in chenopod scrub, None.Suitable saline and wetland (Centromadia pungens ssp. CRPR 1B.1 meadows and seeps, playas, riparian woodland,and valley habitat is absent from the project site laevis) and foothill grassland. Found in San Bernardino, Los Angeles, and the species has not been Riverside,and San Diego Counties. Flowering Period:April to previously recorded within the September. Elevation: below 2,100 feet(640 meters). immediate vicinity.

C-3

1205 Melrose Way Project
Attachment C (cont.)
Special Status Plant Species Potential to Occur
Species Status' Habit,Ecology and Life History Potential to Occur Orcutt's pincushion -/- Annual herb. Found on coastal dunes and sandy areas within None.Suitable sandy soils are present; (Chaenactis glabriuscula var. CRPR 16.1 coastal bluff scrub.Typically, in proximity to moist ocean however,the project site is located orcuttiana) breezes from Ventura County south to San Diego County. above the species known elevation Elevation: below 330 feet(100 meters). Flowering Period: range,and this species has not January to August. previously been recorded nearby.

Summer holly -/- Perennial shrub. Occurs in chaparral and cismontane Presumed Absent. No suitable habitat (Comarostaphylis diversifolia CRPR 16.2 woodland. Found in Santa Barbara,Orange, Riverside,and present on-site. Plus,this perennial ssp.diversifolia) MHCP Covered San Diego Counties. Flowering period:April to June. species would have been observed Elevation:95 to 2,590 feet(30 to 790 meters). during biological surveys and was not detected.

Small-flowered morning-glory -/- Annual herb.Occurs on clay soils and serpentinite seeps in Low.Suitable clay soils are present (Convolvulus simulans) CRPR 4.2 openings within chaparral,coastal scrub,and native within the project site, however there grassland. Found within the San Francisco Bay area,San are not suitable habitats for this Joaquin Valley,western Sierra Nevada foothills,along the species as site has been historically coast of southern California,the Channel Islands,and the altered/disturbed. western Transverse and Peninsular Ranges. Flowering period:

April to June. Elevation:95 to 2,430 feet(30 to 740 meters).

Del Mar Mesa sand aster -/- Perennial herb. Found on sandy soils and disturbed areas Presumed Absent. No suitable habitat (Corethrogyne filaginifolia var. CRPR 113.1 within southern maritime chaparral,coastal sage scrub,and present on-site. Plus,this perennial linifolia) MHCP Covered coastal bluffs. Found in San Diego County. Flowering Period: species would have been observed May to September. Elevation:45 to 490 feet(15 to during biological surveys and was not 150 meters). detected.

Wiggins'cryptantha -/- Annual herb. Occurs in coastal scrub habitat,often in clay Low.Suitable clay soils are present (Cryptantha wigginsii) CRPR 16.2 soils. Flowering period: February to June. Elevation: 65 to within the project site, however there 900 feet(20 to 275 meters). are not suitable habitats for this species as site has been historically
altered/disturbed.

Western dichondra -/- Perennial herb. Found among rocks and shrubs within Presumed Absent. No suitable habitat (Dichondra occidentalis) CRPR 4.2 grasslands,coastal sage scrub,chaparral,and oak woodlands. present on-site. Plus,this perennial Often proliferates on recently burned slopes. Found along species would have been observed the coastal regions from San Luis Obispo County south to San during biological surveys and was not Diego County. Flowering period: March to July. Elevation: detected. 165 to 1,640 feet(50 to 500 meters).

C-4

1205 Melrose Way Project
Attachment C (cont.)
Special Status Plant Species Potential to Occur
Species Status' Habit,Ecology and Life History Potential to Occur Blochman's dudleya -/- Perennial succulent.Grows on open, rocky slopes,often on Presumed Absent. No suitable habitat (Dudleya blochmaniae ssp. CRPR 16.1 serpentine or clay dominated soils in coastal sage scrub and present on-site. Plus,this perennial blochmaniae) valley grassland communities. Found along the coast from species would have been observed San Luis Obispo south to San Diego County. Flowering period: during biological surveys and was not April to June. Elevation: 15 to 1,475 feet(5 to 450 meters). detected.

Sticky dudleya -/- Perennial succulent. Occurs in rocky areas within coastal Presumed Absent. No suitable habitat (Dudleya viscida) CRPR 16.2 bluffs,coastal sage scrub,chaparral, and woodlands.Grows present on-site. Plus,this perennial primarily on very steep north-facing slopes. Found in Orange, species would have been observed Riverside,and San Diego Counties. Flowering period: May to during biological surveys and was not June. Elevation: 30 to 1,805 feet(10 to 550 meters). detected.

San Diego button celery FE/SE Annual or perennial herb.Grows in vernal pools and other Presumed Absent. No suitable habitat (Eryngium aristulatum var. CRPR 113.1 mesic areas,such as marshes. Found in Los Angeles,Orange, present on-site. Plus,this perennial parishii) Riverside, and San Diego Counties. Flowering period:April to species would have been observed June. Elevation: 65 to 2,035 feet(20 to 620 meters). during biological surveys and was not detected.

Sand-loving wallflower -/- Perennial herb. Found in open areas and sandy soils within Presumed Absent. No suitable habitat (Erysimum ammophilum) CRPR 16.2 coastal dunes,coastal strand,coastal sage scrub,and present on-site. Plus,this perennial maritime chaparral. Found within northern Monterey species would have been observed County,San Diego County,and the northern Channel Islands. during biological surveys and was not Flowering Period: February to June. Elevation: below detected. 195 feet(60 meters).

Cliff spurge -/- Perennial shrub. Found in rocky areas of coastal bluffs, Presumed Absent. No suitable habitat (Euphorbia misera) CRPR 213.2 coastal sage scrub, and Mojave desert scrub. Found in present on-site. Plus,this perennial Riverside, Orange,and San Diego Counties and the Channel species would have been observed Islands. Flowering period: December to August. Elevation: 30 during biological surveys and was not to 1,640 feet(10 to 500 meters). detected.

San Diego barrel cactus -/- Perennial (stem succulent)shrub.Grows in sandy to rocky Presumed Absent. No suitable habitat (Ferocactus viridescens) CRPR 213.1 areas within chaparral,valley grassland and coastal sage present on-site. Plus,this perennial MHCP Covered scrub communities. Found in San Diego County Flowering species would have been observed period: May to June. Elevation: 5 to 492 feet(3 to during biological surveys and was not 450 meters). detected.

C-5

1205 Melrose Way Project
Attachment C (cont.)
Special Status Plant Species Potential to Occur
Species Status' Habit,Ecology and Life History Potential to Occur Palmer's grapplinghook -/- Annual herb. Found in clay soils in annual grasslands and Presumed Absent. No suitable habitat (Harpagonella palmeri) CRPR 4.2 coastal sage scrub. Flowering Period: March to May. present on-site. Plus,this perennial Elevation: 65 to 3,100 feet(20 to 955 meters). species would have been observed during biological surveys and was not
detected.

Orcutt's hazardia --/ST Perennial shrub. Often grows on clay soils within coastal sage Presumed Absent. No suitable habitat (Hazardia orcuttii) CRPR 16.1 scrub and southern maritime chaparral. Found in San Diego present on-site. Plus,this perennial MHCP Covered County. Flowering period:August to October. Elevation: 260 species would have been observed to 280 feet(80 to 85 meters). during biological surveys and was not detected.

Decumbent goldenbush -/- Perennial shrub. Occurs in sandy soil and disturbed areas on Presumed Absent. No suitable habitat (Isocoma menziesii var. CRPR 113.2 the inland side of dunes, hillsides,and arroyos within coastal present on-site. Plus,this perennial decumbens) sage scrub and chaparral communities. Found in along the species would have been observed coast of southern California, Peninsular Ranges,and Channel during biological surveys and was not Islands. Flowering period:July to November. Elevation: below detected. 656 feet(200 meters).

San Diego marsh-elder -/- Perennial herb. Found in alkaline flats,depressions,and Presumed Absent. No suitable habitat (Iva hayesiana) CRPR 26.2 streambanks within wetland communities in San Diego present on-site. Plus,this perennial MHCP Covered County. Flowering period:April to October. Elevation:30 to species would have been observed 1,640 feet(10 to 500 meters). during biological surveys and was not detected.

Southwestern spiny rush -/- Perennial herb. Found in moist saline environments such as Presumed Absent. No suitable habitat (Juncus acutus ssp.leopoldii) CRPR 4.2 alkaline seeps and meadows,and coastal salt marshes and present on-site. Plus,this perennial swamps. Found along the coastal regions from San Luis species would have been observed Obispo south to San Diego County. Flowering period: May to during biological surveys and was not June. Elevation: below 984 feet(300 meters). detected.

Robinson's pepper-grass -/- Annual herb.Grows in openings of sage scrub and chaparral Low. No suitable habitat for this (Lepidium virginicum var. CRPR 4.3 at the coastal and foothill elevations throughout California. species as the site has been historically robinsonii) Typically observed in relatively dry,exposed locales rather altered/disturbed. than beneath a shrub canopy.Also,found in disturbed areas.

Flowering period: March to June. Elevation: below 9,186 feet (2,800 meters).

C-6

1205 Melrose Way Project
Attachment C (cont.)
Special Status Plant Species Potential to Occur
Species Status' Habit,Ecology and Life History Potential to Occur Sea dahlia -/- Perennial herb. Occurs within coastal scrub and coastal bluffs Presumed Absent. No suitable habitat (Leptosyne maritima) CRPR 26.2 scrub in San Diego County. Flowering period: March to May. present on-site. Plus,this perennial Elevation: below 490 feet(150 meters). species would have been observed during biological surveys and was not
detected.

Little mousetail -/- Annual herb. Occurs in alkaline vernal pools within native None.Suitable alkaline soils and vernal (Myosurus minimus ssp.apus) CRPR 3.1 grassland. Flowering period: March to June. Found within wetland habitat is absent from the MHCP Covered San Joaquin Valley south to San Diego County and east to project site and the species has not western Riverside and San Bernardino Counties. Elevation: been previously recorded nearby. 65 to 2,100 feet(20 to 640 meters).

Mud nama -/- Annual herb.Occurs in intermittently wet areas such as None.Suitable fringe wetland habitat (Nama stenocarpa) CRPR 213.2 streambanks and muddy lake edges. Found in the San is absent from the project site and the Joaquin Valley,southern coast, Peninsular Ranges,Sonoran species has not been previously Desert, and Channel Islands. Flowering period:January to recorded nearby.

July. Elevation: 15 to 1,640 feet(5 to 500 meters).

Spreading navarretia FT/-- Annual herb.Occurs in vernal pools,vernal swales, roadside None.Suitable vernal wetland habitat (Navarretia fossalis) CRPR 16.1 depressions, playas, marshes and swamps, and chenopod is absent from the project site and the MHCP Covered scrub. Population size is strongly correlated with rainfall. species has not been previously Depth of pool appears to be a significant factor as this recorded nearby. species is rarely found in shallow pools. Found in the Mojave Desert, desert mountains,Channel Islands,and the
Transverse and Peninsular Ranges. Flowering period:April to June. Elevation:98 to 4,265 feet(30 to 1,300 meters).

Coast woolly-heads -/- Annual herb.Occurs within coastal dunes;seems to prefer None.Suitable coastal dune habitat is (Nemacaulis denudata var. CRPR 16.2 the back dunes in mildly protected areas. Flowering Period: absent from the project site and the denudata) April to September. Elevation: below 330 feet(100 meters). species has not been previously recorded nearby.
slender cottonheads -/- Annual herb. Grows on desert dunes and sandy areas of None.Suitable desert dune habitat is (Nemacaulis denudata var. CRPR 213.2 Sonoran desert scrub within San Bernardino, Riverside, absent from the project site and the gracilis) Imperial, and San Diego Counties. Flowering period:April to species has not been previously May. Elevation: below 1,310 feet(400 meters). recorded nearby.

C-7

1205 Melrose Way Project
Attachment C (cont.)
Special Status Plant Species Potential to Occur
Species Status' Habit,Ecology and Life History Potential to Occur Nuttall's scrub oak -/- Perennial shrub. Occurs on sandy or clay loam soils near the Presumed Absent. No suitable habitat (Quercus dumosa) CRPR 16.1 coast within coastal scrub,chaparral,cismontane woodland, present on-site. Plus,this perennial MHCP Covered and riparian woodland. Found along the coast, San Jacinto species would have been observed Mountains, and Peninsular Ranges of southern California. during biological surveys and was not Flowering period: March to May. Elevation: below 1,310 feet detected. (400 meters).

Prairie false oat -/- Annual herb.Occurs on clay soils within chaparral habitat. None.Suitable clay soil is present; (Sphenopholis interrupta ssp. CPRP 16.1 Flowering period:April. Elevation: 50 feet(15 meters). however,chaparral habitat is absent californica) from the project site,the species has not been recorded nearby,and the site
is located above the species known
elevation range.
1 Listing codes as follows: F=Federal;S=State of California;E=Endangered;T=Threatened;CE=Candidate Endangered;R=Rare CRPR=California Native Plant Society Rare Plant Rank: 1A—presumed extirpated in California and either rare or extinct elsewhere;1B—rare,threatened,or endangered in California and elsewhere;2A—presumed extirpated in California,but more common elsewhere;2B—rare,threatened,or endangered in California,but more common elsewhere;3—more information needed;4—watch list for species of limited distribution. Extension codes:.1—seriously endangered;.2—moderately endangered; .3—not very endangered.

North County MHCP Covered Species.
z Potential to Occur is assessed as follows:None:There are no present or historical records of the species occurring on or in the immediate vicinity of the study area and the diagnostic habitats and soils associated with the species do not occur on or in the immediate vicinity of the project; Perennial species would have been detected during survey;Low:Suitable habitat is present in the study area and a historical record of the species occurs in the immediate vicinity but existing conditions such as elevation,soils, density of cover,prevalence of non-native species,evidence of disturbance,limited habitat area,and/or isolation substantially reduce the possibility that the species may occur;Moderate:The diagnostic habitats associated with the species occur on or in the immediate vicinity of the study area,but there is not a recorded occurrence of the species within the immediate vicinity.Some species that contain extremely limited distributions may be considered moderate,even if there is a recorded occurrence in the immediate vicinity;High:Suitable habitat occurs in the study area and the species has been recorded recently on or in the immediate vicinity but the species was not observed during project surveys; Present:The species was observed within the study area during biological surveys for the project;Presumed Absent:Species would be visible all year and would have been observed if present.

C-8

Attachment D
Plant Species Potential to Occur

1205 Melrose Way Project
Attachment D
Special Status Animal Species Potential to Occur
Species Status' Habitat Associations Potential to Occur

INVERTEBRATES
Crotch bumble bee --/SCE Found throughout southwestern California from None.Suitable grassland and scrub (Bombus crotchii) the Central Valley south to the U.S./Mexico habitat and associated flowering species border. Inhabits open grasslands and scrub are not present within the project site. habitats. Primarily nests underground and
forages on a wide variety of flowers, but a short
tongue renders it best suited to open flowers
with short corollas. Most commonly observed
on flowering species in the Fabaceae,
Asteraceae,and Lamiaceae families. Occurrence
has also been linked to habitats containing
Asclepius, Chaenactis, Lupinus, Medicago,
Phacelia, and Salvia genera.

VERTEBRATES
Reptiles
Blainville's horned lizard --/SSC In California, predominately occurs from Kern None. Preferred vegetation communities (Phrynosoma blainvillii) County south to San Diego County,west of the and habitat for this species are absent desert at elevations below 8,000 feet. Inhabits a from the site. wide variety of vegetation types including
sagebrush scrub,chaparral,grasslands,forests,
and woodlands but is restricted to areas with
suitable sandy, loose soils with open areas for
basking. Diet primarily composed of native
harvester ants(Pogonmyrmex spp.)and are
generally excluded from areas invaded by
Argentine ants(Linepithema humile).

Birds
Cooper's Hawk --/WL In California, breeds from Siskiyou County south Low.Although marginally suitable tall (Accipiter cooperii) MHCP Covered to San Diego County and eastwards to Owens trees occur within 500 feet of the project Valley at elevations below 9,000 feet. Inhabits site, preferred vegetation communities forests, riparian areas,and more recently and suitable habitat for this species are suburban and urban areas. Nests within dense absent from the site. woodlands and forests and isolated trees in open
areas.

D-1

1205 Melrose Way Project
Attachment D (cont.)
Special Status Animal Species Potential to Occur
Species Status' Habitat Associations Potential to Occur California Black Rail BCC/ST, FP In California, breeds in the Sacramento-San None. No aquatic habitat on-site. (Laterallus jamaicensis coturniculus) Joaquin River delta,San Francisco Bay area, Preferred vegetation communities and Bolinas Lagoon and Tomales Bay in Marin habitat for this species are absent from County, Morro Bay in San Luis Obispo County, the site.

White Slough in San Joaquin County,the Salton
Sea in Imperial County,and the Lower Colorado
River Valley. Inhabits salt and freshwater
marshes and wet meadows.Associated with
pickleweed (Salicornia ssp.), bulrush,alkali heath
(Frankenia salina),and cordgrass(Spartina ssp.).

Requires dense cover of upland vegetation in
tidal areas for protection when rails must leave
marsh habitats during high tide events.

Coastal California Gnatcatcher FT/SSC Year-round resident of California occurring from None. Preferred vegetation communities (Polioptila californica californica) MHCP Covered Ventura County south to San Diego County,and and habitat for this species are absent east to the western portions of San Bernardino from the site. and Riverside Counties.Typically occurs in arid,
open sage scrub habitats on gently slopes
hillsides to relatively flat areas at elevations
below 3,000 feet.Composition of sage scrub in
which gnatcatchers are found varies though
California sagebrush present as dominant or co-
dominant species. Mostly absent from areas
dominated by black sage(Salvia mellifera),white
sage(Salvia apiana),or lemonade berry(Rhus
integrifolia),though may occur more regularly in
inland regions dominated by black sage.

D-2

1205 Melrose Way Project
Attachment D (cont.)
Special Status Animal Species Potential to Occur
Species Status' Habitat Associations Potential to Occur Mammals
Western yellow bat --/SSC Occurs from southern California from in Los None. Preferred vegetation communities (Lasiurusxanthinus) Angeles,San Bernardino,and San Diego and suitable habitats for this species are Counties. In San Diego,commonly found in Anza- absent from the project site.

Borrego Desert but is also established west of
the desert within rural to suburban areas
including Escondido,Vista, Ramona, Lakeside, El
Cajon,and La Mesa. Roosts primarily on dead
palm frond skirts of native and non-native fan
palms but has also been observed in
cottonwoods and yuccas.Occurs within a variety
of habitats where palms are present including
desert riparian,desert washes, palm oasis,
cottonwood-willow riparian forest,and
developed areas.
1 Listing codes are as follows: F=Federal;S=State of California;E=Endangered;T=Threatened;CE=Candidate Endangered;R=Rare;BCC=Federal Bird of Conservation Concern;SSC=State Species of Special Concern;FP=State Fully Protected;WL=Watch List MHCP Covered Species:Covered Species under North County MHCP. z Potential to Occur is assessed as follows:None:Species is so limited to a particular habitat that it cannot disperse on its own,and habitat suitable for its establishment and survival does not occur in the study area;Not Expected:There are no present or historical records of the species occurring on or in the immediate vicinity of the study area.The species moves freely and might disperse through or across the study area,but suitable habitat for residence or breeding does not occur;Low:Suitable habitat is present in the study area and there is a historical record of the species in the project vicinity,but no sign of the species was observed during surveys.Existing conditions such as elevation,species composition,density of cover,prevalence of non-native species,evidence of disturbance,limited habitat area,and/or isolation may substantially reduce the possibility that the species may occur;Moderate:Diagnostic habitats associated with the species occur on or adjacent to the study area,but there is no recent documented occurrence of the species within the immediate vicinity.Some species that contain extremely limited distributions may be considered moderate,even if there is a recorded occurrence in the immediate vicinity;High:Suitable habitat associated with the species occurs in the study area and the species has been recorded recently on or near the project,but was not observed during biological surveys;Present:The species was observed during biological surveys for the project and is assumed to occupy the study area.

D-3

HELIX
Environmental Planning
1205 Melrose Way
Cultural Resources Survey
October 2021 1 04512.00021 .001
Submitted to:

City of Vista
200 Civic Center Drive
Vista, CA 92084-6275
Prepared for.

Summit Environmental Group, Inc.
2810 Cazadero Drive
Carlsbad, CA 92009
Prepared by:

HELIX Environmental Planning, Inc.

Mary Robbins-Wade 7578 El Cajon Boulevard
Cultural Resources Group Manager La Mesa, CA 91942

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1205 Melrose Way
Cultural Resources Survey
Submitted to:

City of Vista
200 Civic Center Drive
Vista, CA 92084-6275
Prepared for:

Summit Environmental Group, Inc.
2810 Cazadero Drive
Carlsbad, CA 92009
Prepared by:

HELIX Environmental Planning, Inc.
7578 El Cajon Boulevard
La Mesa, CA 91942
October 2021 1 04512.00021.001

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National Archaeological Database Information
Authors: James Turner, RPA, Mary Robbins-Wade, RPA, and Theodore Cooley, RPA
Firm: HELIX Environmental Planning, Inc.

Client/Project: Summit Environmental Group, Inc./ 1205 Melrose Way Project Report Date: October 2021
Report Title: Cultural Resources Survey for the 1205 Melrose Way Project, Vista, California
Submitted to: City of Vista
Type of Study: Cultural Resources Survey
New Sites: None
Updated Sites: None
USGS Quad: San Luis Rey 7.5' Quadrangle
Acreage: Approximately 2.7 acres
Key Words: San Diego County;Township 11 South, Range 4 West; Vista; Melrose Way; cultural resource survey

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TABLE OF CONTENTS
Section Page
EXECUTIVE SUMMARY............................................................................................................................. ES-1

1.0 INTRODUCTION................................................................................................................................ 1

1.1 Project Location and Description........................................................................................ 1

1.2 Regulatory Framework ....................................................................................................... 1

1.2.1 California Environmental Quality Act .................................................................... 1

1.2.2 City of Vista General Plan ......................................................................................2

1.2.3 Native American Heritage Values..........................................................................2

1.3 Project Personnel................................................................................................................3

2.0 PROJECT SETTING.............................................................................................................................3

2.1 Natural Setting....................................................................................................................3

2.2 Cultural Setting...................................................................................................................4

2.2.1 Prehistoric Period ..................................................................................................4

2.2.2 Ethnohistory...........................................................................................................5

2.2.3 Historical Background............................................................................................6

2.3 Project Vicinity....................................................................................................................7

3.0 METHODS.........................................................................................................................................8

4.0 RESULTS ...........................................................................................................................................8

4.1 Records Search....................................................................................................................8

4.1.1 Previous Surveys....................................................................................................8

4.1.2 Previously Recorded Resources...........................................................................13

4.2 Other Archival Research ...................................................................................................15

4.3 Native American Contact Program...................................................................................15

4.4 Field Survey.......................................................................................................................16

5.0 SUMMARY AND MANGEMENT RECOMMENDATIONS..................................................................17

5.1 Management Recommendations.....................................................................................18

6.0 REFERENCES...................................................................................................................................19

LIST OF APPENDICES
A Resumes
B Records Search Results (Confidential, Bound Separately) C Native American Correspondence (Confidential, Bound Separately)

TABLE OF CONTENTS (cont.)

LIST OF FIGURES
No. Title Follows Page
1 Regional Location.............................................................................................................................2 2 USGS Topography............................................................................................................................2 3 Aerial Photograph of Project Location..............................................................................................2

LIST OF TABLES
No. Title Page
1 Previous Studies Within One Mile of the Project Area....................................................................9 2 Previously Recorded Resources Within One Mile of the Project Area..........................................13

ACRONYMS AND ABBREVIATIONS
APN Assessor's Parcel Number
BLM Bureau of Land Management
BP Before Present
CCR California Code of Regulations
CEQA California Environmental Quality Act
City City of Vista
CRHR California Register of Historical Resources
GLO General Land Office
HELIX HELIX Environmental Planning, Inc.

NAHC Native American Heritage Commission
NHPA National Historic Preservation Act
NRHP National Register of Historic Places
OHP Office of Historic Preservation
project 1205 Melrose Way Project
PRC Public Resources Code
RCS Resource Conservation and Sustainability
SCIC South Coastal Information Center
SLR San Luis Rey
SR State Route
TCP Traditional Cultural Properties
TCR Tribal Cultural Resources
USGS U.S. Geological Survey
iii

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iv

Cultural Resource Survey for the 1205 Melrose Way Project I October 2021

EXECUTIVE SUMMARY
HELIX Environmental Planning, Inc. (HELIX) was contracted by Summit Environmental Group, Inc.to provide cultural resources services for the 1205 Melrose Way Project (project) in the City of Vista, San Diego County, California.The project is a proposed approximately 2.7-acre residential subdivision consisting of fifteen lots.A cultural resources study including a records search,Sacred Lands File search, Native American outreach, a review of historic aerial photographs and maps, and a pedestrian survey was conducted for the project area.This report details the methods and results of the cultural resources study and has been prepared to comply with the California Environmental Quality Act (CEQA) and Section 106 of the National Historic Preservation Act (NHPA), as amended.

The records search obtained from the South Coastal Information Center(SCIC) on August 23, 2021, indicated that 73 previous cultural resources studies have been conducted within one mile of the project area,two of which overlap with the project area.The records search results also indicated that a total of 34 cultural resources have been previously recorded within one mile of the project area; however, no sites have been recorded within the project site.

The field investigations included an intensive pedestrian survey of the project area by a HELIX archaeologist and a Native American monitor on August 24, 2021.The survey did not result in the identification of any cultural material within the project area.

Based on the results of the current study, no impacts to cultural resources are anticipated. However,the project site was covered by mulch and grasses, and the original ground surface could not be observed. In addition,the project site is located within a culturally sensitive area where there is the potential for buried cultural resources. Based on this, it is recommended that an archaeological and Native American monitoring program be implemented for ground-disturbing activities.The monitoring program would include attendance by the archaeologist and Native American monitor at a pre-construction meeting with the grading contractor and the presence of archaeological and Native American monitors during initial ground-disturbing activities on site. Both archaeological and Native American monitors would have the authority to temporarily halt or redirect grading and other ground-disturbing activity in the event that cultural resources are encountered. If significant cultural material is encountered, the project archaeologist will coordinate with the applicant and City of Vista staff to develop and implement appropriate mitigation measures.

HELIX
Environmental Aramnrog
ES-1

Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 This page intentionally left blank
HELIX
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ES-2

Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 1 .0 INTRODUCTION
HELIX Environmental Planning, Inc. (HELIX) was contracted by Summit Environmental Group to provide cultural resources services for the 1205 Melrose Way Project (project) in the City of Vista, San Diego County, California.The project is a proposed approximately 2.7-acre residential subdivision consisting of fifteen lots. A cultural resources study including a records search, Sacred Lands File search, Native American outreach, a review of historic aerial photographs and maps, and a pedestrian survey was conducted for the project area.This report details the methods and results of the cultural resources study and has been prepared to comply with the California Environmental Quality Act (CEQA) and Section 106 of the National Historic Preservation Act (NHPA) of 1966, as amended. 1 .1 PROJECT LOCATION AND DESCRIPTION
The project is located in the City of Vista (City) in northwestern San Diego County(Figure 1, Regional Location).The project is located south of State Route (SR) 78 and west of South Melrose Drive,within Section 25 of Township 11 South, Range 4 West, on the U.S. Geological Survey(USGS) 7.5' San Luis Rey quadrangle (Figure 2, USGS Topography).The approximately 2.70-acre project site is located within Assessor's Parcel Numbers (APNs) 1661-84-10000, 1661-84-0900, and 1661-83-1700, and is bordered by Melrose Way to the south (Figure 3,Aerial Photograph of Project Location).

The 1205 Melrose Way Project proposes to construct 15 single-family detached residences, a new private street, and associated hardscape improvements.The existing residence and associated hardscape improvements will be demolished. Additional off-site improvements consist of grading adjacent to the northeast corner of the project area, and the construction of a permanent gravel access road connecting to the northwest corner of the project area.The off-site improvements include an additional 0.15-acre area, for a study area totaling 2.85 acres. 1 .2 REGULATORY FRAMEWORK

1.2.1 California Environmental Quality Act
The California Environmental Quality Act(CEQA) Guidelines (§15064.5) address determining the significance of impacts to archaeological and historic resources. Cultural resources are defined as buildings, sites, structures, or objects, each of which may have historical, architectural, archaeological, cultural, and/or scientific importance (Office of Historic Preservation [OHP] 1995). Significant resources are designated as "historical resources," and are defined per Public Resources Code 21084.1 and CEQA Guidelines, California Code of Regulations (CCR)Title 14 Section 15064.5 as follows:
• resource(s) listed or eligible for listing in the California Register of Historic Resources (CRHR) (14 CCR Section 15064.5[a][1])
• resource(s) either listed in the National Register of Historic Places (NRHP) or in a "local register of historical resources" unless "the preponderance of evidence demonstrates that it is not historically or culturally significant" (14 CCR Section 15064.5[a][2]) • resources identified as significant in a historical resource survey meeting the requirements of Section 5024.1(g) of the Public Resources Code (14 CCR Section 15065.5[a][2]) HELIX
Environmental Aramnrog
1 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 For listing in the CRHR, a historical resource must be significant at the local, state, or national level under one or more of the following four criteria:
1) It is associated with events that have made a significant contribution to the broad patterns of local or regional history, or the cultural heritage of California or the United States; 2) It is associated with the lives of persons important to local, California, or national history; 3) It embodies the distinctive characteristics of a type, period, region, or method of construction, or represents the work of a master or possesses high artistic values; 4) It has yielded or has the potential to yield information important to the prehistory or history of the local area, California, or the nation.

All resources nominated for listing must have integrity, which is the authenticity of a historical resource's physical identity evidenced by the survival of characteristics that existed during the resource's period of significance. Resources,therefore, must retain enough of their historic character or appearance to be recognizable as historical resources and to convey the reasons for their significance.

Integrity is evaluated with regard to the retention of location, design, setting, materials, workmanship, feeling, and association.A resource must also be judged with reference to the particular criteria under which it is proposed for nomination.

Under 14 CCR Section 15064.5(a)(3),the final category of"historical resources" may be determined at the discretion of the lead agency.

1.2.2 City of Vista General Plan
The Resource Conservation and Sustainability (RCS) Element of the Vista General Plan 2030 includes the following goals related to cultural resources:
• RCS Goal 11: Continue to preserve and protect places, buildings, and objects that embody the City's social, cultural, commercial, architectural, and agricultural history. • RCS Goal 12: Acknowledge, preserve, and protect the City's Native American Heritage.

Sub-items under Goal 12 mandate coordination with the State Native American Heritage Commission (NAHC) and the San Luis Rey Band of Luiseno Mission Indians.

1.2.3 Native American Heritage Values
Under the guidance of the City's General Plan, cultural resources can also include Traditional Cultural Properties (TCP), such as gathering areas, landmarks, and ethnographic locations in addition to archaeological districts. "Traditional" in this context refers to those beliefs, customs, and practices of a living community of people that have been passed down through the generations, usually orally or through practice.The traditional cultural significance of a historic property,then, is significance derived from the role the property plays in a community's historically rooted beliefs, customs, and practices (Parker and King 1998). Generally, a TCP may consist of a single site, or group of associated archaeological sites (district or traditional cultural landscape), or an area of cultural/ethnographic importance.

HELIX
Environmental Aramnrog
2 1205 Melrose Way

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Environmental Planning
Figure 1

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Environmental Planning
Figure 3

Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 In addition to the historical resources described above, per Section 21084.2 of the Public Resources Code,the City must take into account the proposed project's impacts on Tribal Cultural Resources (TCR), separately defined in Section 21074 of the Public Resources Code. As a general concept, a TCR is similar to the federally defined TCP; however, it incorporates consideration of local and state significance and required mitigation under CEQA.To determine whether the proposed project may have an impact on tribal cultural resources,the City is conducting government-to-government consultation with California Native American tribes that have requested such consultation per Section 21080.3.1 of the Public Resources Code. Results of this consultation will be documented separately by the City as part of the CEQA process.
1 .3 PROJECT PERSONNEL
Mary Robbins-Wade M.A., RPA served as principal investigator and provided the senior review of this technical report. Ms. Robbins-Wade meets the qualifications of the Secretary of Interior's Standards and Guidelines for archaeology.James Turner, M.A., RPA conducted the field survey and is the primary author of this report.Theodore Cooley served as a contributor to the report. Logovi'i Sialo'i (Luiseno Native American monitor)from Saving Sacred Sites participated in the pedestrian survey. Resumes for key project personnel are presented in Appendix A.

2.0 PROJECT SETTING

2.1 NATURAL SETTING
The project area is situated within the coastal plain of western San Diego County, where the climate is characterized as semi-arid steppe, with warm, dry summers and cool, moist winters (Hall 2007; Pryde 2004).The Buena Vista Creek is located approximately 0.5 mile to the north of the project area.The elevation of the project area ranges from approximately 350 to 370 feet above mean sea level.

The project area is characterized predominantly by urban development comprised of residential development. Areas immediately surrounding the project area include transportation infrastructure and residential, large-scale recreational/commercial, and industrial development.

Geologically,the project area is underlain by undivided Tonalite that dates to the mid-Cretaceous (Kennedy and Tan 2007).The area south of Melrose Way is underlain by the Santiago formation,which dates to the mid-Eocene (Kennedy and Tan 2007).Two soil series are mapped for the project site:

Placentia sandy loam (5 to 9 percent slopes, eroded), and Bosanko clay(9 to 15 percent slopes).The Placentia sandy loam, consisting of sandy loam and sandy clay that supports the growth of citrus and grasses, is found within most of the project area;the Bosanko clay, a series consisting of sandy clay that typically grows annual grasses, was found within the southeastern corner of the project area (Natural Resources Conservation Service 1997a, b).

Prehistorically, the natural vegetation in the project vicinity likely consisted of coastal sage scrub, riparian, grassland, and freshwater marsh communities.The coastal sage scrub community would have covered most of the canyons in the coastal areas with interspersed areas of native grasslands (Stipa, Elymus, Poa, Muhlenbergia). Prior to historic and modern activities, major drainages contained extensive stands of the riparian community with plants such as sycamore (Platanus racemosa), Fremont cottonwood (Populus fremontii), coast live oak (Quercus agrifolia), and willow (Salix sp.) (Beauchamp HELIX
Environmental Aramnrog
3 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 1986; Munz 1974). Many of the native plant species found in these vegetation communities and those found in the project vicinity are known to have been used by native populations for food, medicine, tools, and ceremonial and other uses (Bean and Shipek 1978; Sparkman 1908). Many of the animal species living within these communities (such as rabbits, deer, small mammals, and birds) would have been used by native inhabitants as well.

2.2 CULTURAL SETTING

2.2.1 Prehistoric Period
The earliest well-documented sites in the San Diego area belong to the San Dieguito Tradition, dating to over 9,000 years ago (Warren 1967; Warren et al. 1998).The San Dieguito Tradition is thought by most researchers to have an emphasis on big game hunting and coastal resources (Warren 1967). Diagnostic material culture associated with the San Dieguito complex includes scrapers, scraper planes, choppers, large blades, and large projectile points(Rogers 1939; Warren 1967). In the southern coastal region,the traditional view of San Diego prehistory has the San Dieguito Tradition followed by the Archaic Period, dating from circa 8600 Before Present(BP)to circa 1300 BP (Warren et al. 1998).

A large number of archaeological site assemblages dating to this period have been identified at a range of coastal and inland sites.These assemblages, designated as the La Jolla/Pauma complexes, are considered part of Warren's (1968) "Encinitas tradition" and Wallace's (1955) "Early Milling Stone Horizon."The Encinitas tradition is generally"recognized by millingstone assemblages in shell middens, often near sloughs and lagoons" (Moratto 1984:147) and brings a shift toward a more generalized economy and an increased emphasis on seed resources, small game, and shellfish. The local cultural manifestations of the Archaic period are called the La Jollan complex along the coast and the Pauma complex inland. Pauma complex sites lack the shell that dominates many La Jollan complex site assemblages. Sites dating to the Archaic Period are numerous along the coast, near-coastal valleys, and around estuaries. In the inland areas of San Diego County, sites associated with the Archaic Period are less common relative to the Late Prehistoric complexes that succeed them (Cooley and Barrie 2004; Laylander and Christenson 1988; Raven-Jennings and Smith 1999;True 1970).The La Jolla complex tool assemblage is dominated by rough cobble tools, especially choppers and scrapers (Moriarty 1966).The La Jolla complex tool assemblage also includes manos and metates,terrestrial and marine mammal remains,flexed burials, doughnut stones, discoidals, stone balls, plummets, biface points, beads, and bone tools (True 1958, 1980).

While there has been considerable debate about whether San Dieguito and La Jollan patterns might represent the same people using different environments and subsistence techniques, or whether they are separate cultural patterns (e.g., Bull 1983; Ezell 1987; Gallegos 1987; Warren et al. 1998), abrupt shifts in subsistence and new tool technologies occur at the onset of the Late Prehistoric Period (1500 BP to AD 1769).The Late Prehistoric period is characterized by higher population densities and intensification of social, political, and technological systems.The Late Prehistoric period is represented by the San Luis Rey(SLR) complex in the northern portion of San Diego County and the Cuyamaca complex in the southern portion.

The SLR complex is divided into two phases: SLR I and SLR II. Elements of the SLR complex include small, triangular, pressure-flaked projectile points (generally Cottonwood series, but Desert Side-notched series also occurs); milling implements: mortars and pestles, manos and metates, and bedrock milling features; bone awls; Olivella shell beads; other stone and shell ornaments; and cremations (Meighan HELIX
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4 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 1954; Moratto 1984;True et al. 1974).The later SLR II complex also includes several elements not found in the SLR I complex: "pottery vessels, cremation urns, red and black pictographs, and such nonaboriginal items as metal knives and glass beads" (Meighan 1954:223).

SLR I was originally thought to date from AD 1400 to AD 1750, with SLR 11 dating between AD 1750 and AD 1850 (Meighan 1954). However, that division was based on the assumption that the Luiseno did not practice pottery manufacture until just prior to the arrival of the Spanish.The chronology has since been revised due to evidence that pottery may have been introduced to the Luiseno circa AD 1200 to 1600.

Ceramics were probably introduced from the Luisenos' southern neighbors,the Kumeyaay(True et al. 1974).

Based on ethnographic data, including the areas defined for the Hokan-based Yuman-speaking peoples (Kumeyaay) and the Takic-speaking peoples (Luiseno) at the time of contact, it is generally accepted that the Cuyamaca complex is associated with the Yuman Kumeyaay and the San Luis Rey complex with the Shoshonean Luiseno.The name Luiseno derives from Mission San Luis Rey de Francia and has been used to refer to the Indian people associated with that mission, while the Kumeyaay people are also known as Ipai,Tipai, or Diegueno (named for Mission San Diego de Alcala). Agua Hedionda Creek is often described as the division between the territories of the Luiseno and the Kumeyaay people (Bean and Shipek 1978; Luomala 1978; White 1963), although various archaeologists and ethnographers use slightly different boundaries. Native people know their traditional use areas through traditional stories and songs.

2.2.2 Ethnohistory
The name Luiseno derives from Mission San Luis Rey de Francia and has been used to refer to the Native people associated with the mission.The Luiseno language belongs to the Cupan group of the Takic subfamily and is part of the widespread Uto-Aztecan language family(Bean and Shipek 1978; Sparkman 1908; White 1963). Neighboring groups that speak Cupan languages are Cupeno, Cahuilla, and Gabrielino.The people associated with Mission San Juan Capistrano were called Juaneno by the Spanish; they call themselves Acjachemen.The language, culture, and territory of the Luiseno and Juaneno people are so closely related that the two are sometimes considered by ethnographers to be a single ethnic nationality(Bean and Shipek 1978; White 1963); however,the Luiseno and Juaneno people consider themselves to be separate tribes, as do some ethnographers (e.g., Kroeber 1976 [1925]).

Cameron (1987:319-321) noted archaeological differences between the two groups.

Ethnographic and ethnohistoric studies of the Luiseno include Bean and Shipek (1978), Boscana (1947), Kroeber(1976 [1925]), Robinson (1947), Shipek(1977), Sparkman (1908),Talley(1982), and White (1963).Archaeological studies addressing the Late Prehistoric San Luis Rey complex include Meighan (1954), McCown (1955),True et al. (1974), and Wallace (1960). Most of the ethnographic studies, as well as the "classic" archaeological studies of the Luiseno, have concentrated on the Pauma Valley and the Palomar Mountain area, although Wallace's (1960) study was an archaeological survey of the Buena Vista Creek watershed.

It must be noted that interpretations by archaeologists and linguistic anthropologists may differ from the beliefs and traditional knowledge of the Luiseno people.The Luiseno creation story indicates that the Luiseno people have always been here, not migrating from elsewhere.The creation story of the Pechanga Band of the Luiseno tells that the world was created at Temecula. "The Kaamalam [first people] moved to a place called Nachiivo Pomiisavo, but it was too small, so they moved to a place HELIX
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5 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 called 'exva Temeeku,'this place you now know as Temeku. Here they settled while everything was still in darkness (DuBois 1908)" (Masiel-Zamora 2013:2). A traditional Luiseno story tells of a great flood, and the people went to higher ground, where they were saved.The San Luis Rey Band say that this higher ground where the people were saved is Morro Hill. Some Luiseno informants indicated the place in this story is a hill just east of Highway 395 in the San Luis Rey River Valley (Cupples and Hedges 1977).

2.2.3 Historical Background

2.2.3.1 Spanish Period
While Juan Rodriguez Cabrillo visited San Diego briefly in 1542, the beginning of the historic period in the San Diego area is generally given as 1769. It was that year that the Royal Presidio of San Diego was founded on a hill overlooking Mission Valley.The Mission San Diego de Alcala was constructed in its current location five years later.The Spanish Colonial period lasted until 1821 and was characterized by religious and military institutions bringing Spanish culture to the area and attempting to convert the Native American population to Christianity. Mission San Diego was the first mission founded in Southern California. In 1798,the Mission San Luis Rey De Francia was founded in northern San Diego County.

Covering almost 950,400 acres,the Mission raised about 26,000 cattle, as well as other livestock(Young and Levick 1988). In the years that followed its establishment,the population of the Luiseno people declined rapidly due to disease (Lightfoot 2004).

2.2.3.2 Mexican Period
Although Mexico gained its independence from Spain in 1821,Spanish patterns of culture and influence remained for a time.The missions continued to operate as they had in the past, and laws governing the distribution of land were also retained in the 1820s. Following the secularization of the missions in 1834, large ranchos were granted to prominent and well-connected individuals, ushering in the Rancho Era, with the society making a transition from one dominated by the church and the military to a more civilian population,with people living on ranchos or in pueblos.With the numerous new ranchos in private hands, cattle ranching expanded and prevailed over agricultural activities.

The project site is located approximately 0.6 mile northeast of the former Agua Hedionda Rancho land grant.The 13,311-acre Rancho was granted to Don Juan Maria Marron in the 1840s and covered an area extending from the Pacific Ocean almost to Vista from Carlsbad (Moyer 1969). Initially utilized for sheep ranching, Don Marron used the land primarily for cattle ranching(Christenson and Sweet 2008).

2.2.3.3 American Period
The American period began in 1848,when California was ceded to the United States. The territory became a state in 1850.Terms of the Treaty of Guadalupe Hidalgo brought about the creation of the Lands Commission in response to the Homestead Act of 1851,which was adopted as a means of validating and settling land ownership claims throughout the state. Few of the large Mexican ranchos remained intact, due to legal costs and the difficulty of producing sufficient evidence to prove title claims. Much of the land that once constituted rancho holdings became available for settlement by immigrants to California.The influx of people to California and to the San Diego region resulted from several factors, including the discovery of gold in the state,the end of the Civil War, the availability of free land through the passage of the Homestead Act, and later,the importance of San Diego County as an agricultural area supported by roads, irrigation systems, and connecting railways. During the late nineteenth and early twentieth centuries, rural areas of San Diego County developed small agricultural HELIX
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6 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 communities centered on one-room schoolhouses. Such rural farming communities consisted of individuals and families tied together through geographical boundaries, a common schoolhouse, and a church. Farmers living in small rural communities were instrumental in the development of San Diego County.They fed the growing urban population and provided business for local markets. Rural farm school districts represented the most common type of community in the county from 1870 to 1930.

When Don Juan Maria Marron, owner of the nearby Rancho Agua Hedionda, died in 1853, his widow and children inherited the majority of Rancho Agua Hedionda, along with Marron's brother, Silvestre Marron,who inherited 360 acres of the rancho lands (Moyer 1969).The Rancho was leased by the Marr6ns to Frances Hinton in 1860 for$6000, and in 1865, Hinton assumed full ownership of the property after drought decimated the grazing lands for which it was valued. Hinton died five years later and willed Rancho Agua Hedionda to his mayordomo, Robert Kelly,who had served as the mayordomo for Jamacha Rancho in San Diego.

Upon Kelly's death in 1890,the rancho lands again changed hands and became the property of Kelly's nine nieces and nephews. In 1950,the last of Kelly's heirs died, leaving his son Allan 820 acres of the rancho that included the eastern portion of Agua Hedionda Lagoon (Moyer 1969).

The City of Vista was established in 1886 by the Vista Land Company, which purchased a sizeable portion of Rancho Buena Vista, located south of the District. Before this, in 1882,John Frazier applied to open the first post office—initially naming the city"Frazier's Crossing," and then "Buena Vista," Frazier ultimately chose "Vista" when he learned the other two names were already taken (City of Vista n.d.; Vista Historical Society 2020). By the twentieth century, Vista had access to a railroad that linked Oceanside and Escondido (Vista Historical Society 2020).

Vista grew slowly in the early 1910s and 1920s due to the lack of an adequate water supply (City of Vista n.d.).The Vista Irrigation District was created in 1923 to supply the fledgling city with water from Lake Henshaw; local agriculture flourished, and the population boomed. Like most of the nation,Vista felt the effects of the Great Depression; growth resumed in 1936. By 1948,the City had become the "avocado capital of the world" (City of Vista n.d.). Agricultural production reached its peak in the 1960s, and the City voted to incorporate on January 28, 1963 (City of Vista n.d.; Vista Historical Society 2020).

2.3 PROJECT VICINITY
The Buena Vista Creek area was surveyed by Wallace in the 1950s, and 37 open habitation sites (recorded as campsites)were recorded within the watershed (1960). Fifteen of the sites had marine shellfish remains present, but shell was abundant at only three of the sites (Wallace 1960). Most of the sites also had lithic artifacts (ground stone and flaked stone), and several had bedrock milling features.

Wallace noted that the sites in the Buena Vista area showed evidence of occupation during three different temporal periods. Ceramic sherds were found at three of the sites, indicative of the Late Prehistoric San Luis Rey complex, and several sites appeared to represent the Pauma and La Jolla complexes, which as discussed above, are generally now thought to be contemporaneous (Gallegos 1987).

As mentioned above,the project site is approximately 0.6 mile northwest of the historic Mexican land grant Rancho Agua Hedionda, which was granted to Juan Maria Romouldo Marron in 1842. The original home built by Marron at the rancho is sometimes called the Marron Adobe but also known as the Kelly House; it is located several miles from the current study area. A second Marron home,the core of the HELIX
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7 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 historic Marron-Hayes Adobe, was built by Sylvestre Marron sometime between 1842 and 1851.

Ownership of the vast majority of the Rancho Agua Hedionda eventually passed to Robert Kelly, with 360 acres retained by Sylvestre Marron's family. In 1875, Sylvestre's daughter, Felipe, married J.

Chauncey Hayes, son of Judge Benjamin I. Hayes.The couple lived in an adobe house (the Marron Adobe) about .25 mile west of Sylvestre's home (the Marron-Hayes Adobe). By the 1960s, little remained of the Marron Adobe (see Kyle et al. 2000; Mikesell 2000; Rush 1965), and the remnants of this house are recorded as archaeological site CA-SDI-9474H.

During the 1940s Fred Hayes, son of J. Chauncey and Felipe, purchased the 360-acre parcel that had been owned by his grandfather, Sylvestre Marron. In 1947 Fred Hayes undertook the remodeling and restoration of the Marron-Hayes Adobe.The house currently retains much of its appearance from the 1947 remodel.The Adobe,which is owned and occupied by Shelley Hayes Caron, has been determined eligible for the National Register of Historic Places and the California Register of Historical Resources.

3.0 METHODS
HELIX obtained a records search of the project site and a one-mile radius from the South Coastal Information Center(SCIC) at San Diego State University, San Diego on August 24, 2021.The records search covered a one-mile radius around the project area and included the identification of previously recorded cultural resources and locations and citations for previous cultural resources studies. A review of the California Historical Resources and the state Office of Historic Preservation (OHP) historic properties directories was also conducted.The records search maps are included as Confidential Appendix B to this report. Historic maps and aerial photographs were reviewed to assess the potential for historic archaeological resources to be present.

The NAHC was contacted on August 21, 2021,for a Sacred Lands File search and list of Native American contacts,which were received on September 20, 2021. Letters were sent on September 21, 2021,to the contacts listed by the NAHC. Native American correspondence is included as Confidential Appendix C to this report.

A pedestrian field survey of the project site was conducted by HELIX archaeologist James Turner and Native American monitor Logovi'i Sialo'i of Saving Sacred Sites on August 23, 2021. A residential structure constructed prior to 1964 is present within the project site; this structure was not evaluated or documented for CEQA significance as part of the current cultural resources study.

4.0 RESULTS

4.1 RECORDS SEARCH

4.1.1 Previous Surveys
The records search results identified 73 previous cultural resource studies within the record search limits,two of which overlap with the project area (Table 1, Previous Studies within One Mile of the Project Area).The studies include 26 cultural resource surveys and site visits, 13 archaeological studies, eight monitoring reports, six testing and data recovery reports, five investigations, and four cultural resource assessments.The remaining studies include two environmental impact reports,the results of two record searches, two inventories,two constraint analyses, a nomination form, and an evaluation.

HELIX
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8 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 The two studies that overlap with the project area include a historic resources survey(Marben-Laird Associates 1987) and a cultural resources evaluation for the Vista and Buena Sanitation District's 2007 Sewer Master Plan Update (Rosenberg, Dorrler, and Smith, 2007).

Table 1

PREVIOUS STUDIES WITHIN ONE MILE OF THE PROJECT AREA
Report Number Year Author Report Title (SD-)
00192 1978 Berryman,Stanley Archaeological Field Investigation:Adult Mobile Home Park R. in Vista
00296 1973 Bull, Charles S. An Archaeological Impact Statement for A. F.Anzlover of and Paul Centurion International
H. Ezell
00359 1975 Carrico, Richard Archaeological Survey of the TMI Project 00574 1979 Carrillo, Charles McMillin North Pointe:Archaeological Studies of SDM W and Charles Bull 2133,Oceanside,California
00575 1980 Carrillo, Charles Archaeological Survey of the Radestock property,Vista, California
00690 1975 Fink,Gary R. Archaeological Survey for the Proposed Vista Center Addition,Vista, California
00192 1978 Berryman,Stanley Archaeological Field Investigation:Adult Mobile Home Park R. in Vista
00746 1977 Chace, Paul G. An Archaeological Survey of the Buena Vista Creek Relief Trunk Sewer Line, in the City of Vista, California (E-77-89) 00814 1981 Laylander, Don An Archaeological Assessment of the Bradley Property Near Escondido, County of San Diego.
00840 1980 Laylander, Don An Archaeological and Paleontological Survey of the Karlin Property in the City of Vista,California
01014 1987 Gallegos, Dennis Cultural Resource Survey of the Proposed South Melrose and Andrew Drive Street Improvements,Vista, California Pigniolo
01016 1987 Gallegos, Dennis Cultural Resource Survey of the Mar Vista OV1 Trunk and Andrew Sewer Line,Vista,California
Pigniolo
01023 1986 Gallegos, Dennis Cultural Resource Survey of the Barsby Trunk Line and and Dayle Melrose Way Sewer,Vista,California
Cheever
01089 1979 Franklin, Randy L. An Archaeological Survey for the Proposed Calvin Leung and Richard L. Mobile Home Park, Oceanside,California
Carrico
01329 1989 Pigniolo,Andrew Cultural Resource Investigation:Site SDi-6835 (W-1895) Within the Palomar Airport
Center Project Area
01473 1981 Scientific Archaeological Report on a Portion of the Shadowridge Resource Surveys, Development Project Located in the City of Vista,San Inc. Diego County, California
01502 1986 Wade,Sue A. Archaeological Testing of SDM-W-413,SDM-W-2131,and SDM-W-2132 Oak Riparian Park City of Oceanside,
California
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9 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Report Number Year Author Report Title (SD-)
01672 1980 Walker, Carol J. An Archaeological Test Investigation of Seven Cultural and Charles S. Bull Resources for Leisure Village Oceanside 01874 1984 Hector,Susan Archaeological Survey of Vista Point 02015 1984 Engineering Environmental Assessment San Diego Pipeline Expansion Management Inc. Project Los Angeles, Orange, and San Diego Counties, California
02294 1991 Smith, Brian F. Archaeological Survey of the Vista Centre Project 02694 1993 Mooney, Brian Archaeological Survey Report for a Portion of Adams Street and John Cook Widening Project in the City of Carlsbad,California 03075 1995 Carrico, Richard, Historic Property Survey Report for the State Route 78 Andrew Pigniolo, Corridor Enhancement Project 11-SD-78, P.M. 5.3-9.8, Brian Glenn,and 965100, City of Vista,California
Kathleen
Crawford
03528 1998 Gross,G.Timothy Archaeological Testing of a Portion of SDI-14,809,an and Ruth C.Alter Archaeological Site on a Segment of the South Agua Hedionda Trunk Sewer Carlsbad,California
04110 1990 John Whitehouse A Cultural Resource Survey of the Melrose and Hacienda Commercial Center, City of Vista,California
04111 1982 Larry Seeman Draft Environmental Impact Report Revised Parks and Recreation Element,Carlsbad, California
04116 1978 The City of Vista Environmental Impact Report for the Rancho Vista Area 04308 1979 Westec Services, An Archaeological Survey for The Proposed Calvin Lueng Inc.And R.L. Mobile Home Park, Oceanside,California
Franklin
04361 1991 Gallegos, Dennis Cultural Resources Testing Program for SDI-4922,SDI- and Danielle Huey 4923,SDI-4925,SDI-11941,SAD-11942,SDI-11943,and SDI-12125,Calavera Lake, Carlsbad, California
04806 1994 Strudwick, Ivan H. Historical/Archaeological Survey Report for the Moffatt Parcel Agua Hedionda Lagoon, Carlsbad,California
04835 1982 Corum,Joyce Summary Report for an Archaeological Test Excavation at Site CA-SDI-9473,Oceanside,California. 11-SD-78 P.M.

O.O/3.1
05078 2001 Robbins-Wade, Cultural Resources Inventory for the Taylor Street Mary Extension and Escondido Ave. Extension,Vista,San Diego County,California
07466 1991 ERCE Cultural Resource Testing Programs for SDI-4922, 1923, 1925,4927, 11941, 11942, 11943, 12125 Calavera Lake,
Carlsbad, California
08746 1979 Advance Planning An Archaeological Report Submitted to City of Oceanside, and Research and California, Broad moor-Oceanside Subdivision Phase II Associates Archaeologic Report for Archaeological Site Tmi-4 Oceanside,California
08755 1981 Flower, Douglas Archaeological Investigations of South Ridge Trails and Linda Roth Oceanside,California SDM-W-2130,SDM-W-2135,SDM-W- 2137
08965 2003 Mc Lean, Deborah Archaeological Survey Report West Vista Way Widening, K. B. City of Vista,San Diego County, California
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10 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Report Number Year Author Report Title (SD-)
09291 2004 Robbins-Wade, Buie Condominium Project-Archaeology Mary
09645 2001 Kyle, Carolyn Cultural Resource Assessment/Evaluation for Cingular Wireless Site SD 611-01,San Diego,California
09654 2005 Kyle, Carolyn Cultural Resource Constraint Analysis for the Lake Calavera Trails Project City of Carlsbad,California
09766 2005 Robbins-Wade, Archaeological Resources Survey,West Vista Way Medical Mary Office Project,Vista,San Diego County,California 09935 2004 Aislin-Kay, Marnie Records Search Results for Cingular Telecommunications and Christeen Facility Candidate SD-965-12 (Breeze Hill Park),900 South Taniguchi Melrose Drive,Vista,San Diego County, California 10062 1975 Eckhardt,William Archaeological Survey for TMI Oceanside Property 10551 2006 Arrington,Cindy Cultural Resources Final Report of Monitoring and Findings for the Qwest Network Construction Project,State of
California
10791 1984 Brandes, Nomination Form for the Charles A. Braun House/Willard Raymond and Rick and Susan Michlin House
Alexander
11228* 1987 Marben-Laird Historic Resource Survey,A Project of the City of Vista, Associates California
11388 2007 Robbins-Wade, Archaeological Resources Survey,Vale View Drive Mary and Andrew Subdivision,Vista,San Diego County,California PC2-098 Giletti
11524* 2007 Rosenberg,Seth A Cultural Resources Evaluation for the Vista and Buena A.,Adriane Sanitation District 2007 Sewer Master Plan Update Dorrler,And Brian
F.Smith
11707 2008 Tuma, Michael Archaeological Survey,Testing,and Evaluation of Three W., Caprice D. Bedrock Milling Feature Sites, and Evaluation of One Built Harper, Environment Resource for the Stonemark Estates Project in and Susan Unincorporated San Diego County,California Underbrink
12233 2009 Gardner,Jill Cultural Resources Monitoring for the SDG&E Gas Pipeline Access Road Grading at Calavera Hills, Carlsbad,San Diego County,California
13283 2011 Ruston, Rachel S. Cultural Resources Review and Records Searches for Line 3010 Operations& Maintenance Potholing and Phase 1&
2 Pipeline Integrity/Retrofit Activities
13296 2011 Loftus,Shannon AT&T Site NS0015 Oak Riparian Part LTE 4585 1/2 Lake Boulevard Oceanside,San Diego County,California
13626 2011 Morgan, Nichole TCM Access Road Grading Project, Cultural Resources B. Inventory Report
13633 2010 Blotner, Nicole ETS#20554,Cultural Resources Monitoring for the Gas Grid 3010-10 Project, Carlsbad,San Diego County,
California
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11 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Report Number Year Author Report Title (SD-)
13868 2012 Hoffman, Robin D. Phase II Archaeological Investigation of Site CA-SDi-644,for the Proposed California Highway Patrol Oceanside
Replacement Facility Project,Vista, County of San Diego, California
14069 2011 Ni Ghabhlain, Cultural And Historical Resource Study for the City of Sinead Oceanside General Plan-Circulation Element Update Program Environmental Impact Report(PEIR)
14081 2009 Ni Ghabhlain, Cultural And Historical Resources Survey for the Sinead Downtown Vista Specific Plan Update Program
Environmental Impact Report
14251 2013 Sanka,Jennifer M. Phase I Cultural Resources Assessment Digital Messaging Boards Project City of Vista,San Diego County,California 14701 2005 Kyle, Carolyn E. Cultural Resource Constraint Analysis for the Lake Calavera Trails Project City of Carlsbad,California
14886 2013 Loftus,Shannon Cultural Resource Records Search and Site Survey AT&T Site Ns0016 Ocean Hills Country Club 1298 Navel Place
Vista,San Diego County, California
15876 2014 Carrie D.Wills and Cultural Resource Records Search and Site Visit Results for Sarah Verizon Wireless Candidate'Hackmore Drive', Located At A.Williams 1455 West Vista Way,Vista,San Diego County, California 16560 2015 Castells,Shelby Cultural Resources Study for the Presidio Vista Project, City Gunderman of Vista,San Diego County, California
17149 2017 Garrison,Andrew Cultural Resources Study for the Valencia Drive Project, J.And J.R.K. City of Vista,San Diego County, California Stropes
17233 2017 Brunzell, David San Diego 129 Project,San Diego County, California 17235 2017 Brunzell, David T-Mobile PUC Project 365239, San Diego County,California 17341 2017 Robbins-Wade, South Melrose Self-Storage Project-Cultural Resources Mary and Nicole Survey
Falvey
17468 2015 Wade,Sue Verizon Hackmore Drive/1455 W.Vista Way Telecommunication Facility, PC8-259): Cultural Resource Monitoring
17951 2018 Neal,Jessica and Cultural Resources Review for The Sd34xc785 Stealth Kirby Page-Schmit Tower Project, 171 Unity Way(APN: 164-250-17-00),City of Vista,San Diego County, California
17952 2019 Tactikos,Joanne, Cultural Resources Review for the Sd34xc785 Project, 171 Jessica Neal, and Unity Way, City of Vista,San Diego County, California Kirby Page-Schmit
18543 2020 Pigniolo,Andrew Cultural Resources Monitoring Report for the Storquest Vista Project,City of Vista
18688 2020 Jordan,Amy Archaeological Monitoring for the SDG&E Line Easement Clearance,San Diego County,California
18883 2021 Pigniolo,Andrew Cultural Resources Monitoring Report for the Hacienda Retail Project, City of Vista, California
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12 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Report Number Year Author Report Title (SD-)
19029 2020 O'connor,John Summary of Cultural Resources Monitoring for the Vista Village Drive Trunk Sewer Project,CIP 8212,City of Vista, San Diego County
19236 2018 Daniels,James T. Cultural Resources Study for Sunroad Plaza Project, California
* Overlaps project area

4.1.2 Previously Recorded Resources
The SCIC has a record of 37 previously recorded cultural resources within a one-mile radius of the project, but none have been recorded within the project area (Table 2, Previously Recorded Resources within One Mile of the ProjectAreo). In general,the sites recorded within the one-mile search radius consist of prehistoric resources consisting of habitation and campsites, bedrock milling features, artifact scatters,trails, a pictograph site, and isolated artifacts. One multi-component site is recorded as a medium-sized campsite with historic metal and glass artifacts.Ten historic addresses, a historic building, a segment of a road, and a historic artifact scatter are also documented within the record search limits.

Table 2

PREVIOUSLY RECORDED RESOURCES WITHIN ONE MILE OF THE PROJECT AREA Primary Age and
Number Trinomial Resources Description Recorder,Date (P-37-#) (CA-SDI-#) Present
000637 637 Prehistoric Site Recorded as a campsite; observed artifacts Wallace, 1958 include manos and a hammerstone.
000638 638 Prehistoric Site Small campsite with a petroglyph present on Wallace, 1958; boulder outcrop. Ezell, 1972;
Hedges, 1977
000639 639 Prehistoric Site Large campsite with bedrock metates and Wallace, 1958 mortars.Additional artifacts include ground
stone and flaked stone artifacts.
000640 640 Prehistoric Site Small campsite with associated ground stone Wallace, 1958 artifacts.
000641 641 Prehistoric Site Large campsite with associated ground stone Wallace, 1958 artifacts.
000642 642 Prehistoric Site Small campsite with associated bedrock mortar Wallace, 1958 and ground stone artifacts.
000643 643 Prehistoric Site Campsite with associated ground stone artifacts. Wallace, 1958 000644 644 Multicomponent Medium campsite with flaked stone and ground Wallace, 1958; Site stone artifacts.Subsurface testing recovered Serr and lithic debitage, historic faunal bone fragments, Hoffman, 2011; and historic mental and glass artifacts. Bietz and Castells,2019
000646 646 Prehistoric Site Campsite with associated ground stone artifacts. Wallace, 1958 004918 4918 Prehistoric Site Bedrock milling features with three oval basins. Norwood, 1979 004924 4924 Prehistoric Site High density shell midden deposit.Associated Norwood, 1979 artifacts include flaked stone and fire affected
rock.

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13 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Primary Trinomial Age and
Number (CA-SDI-#) Resources Description Recorder,Date (P-374) Present
004926 4926 Prehistoric Site Milling features with at least three milling slicks. Norwood, 1979 004927 4927 Prehistoric Site Habitation area with midden shell and Norwood, numerous artifacts, including flaked stone, 1979; Huey and ground stone,and ceramic fragments. Baker, 1990
004929 4929 Prehistoric Site Several milling surfaces with an associated light Norwood, 1979 midden deposit.
004930 4930 Prehistoric Site Several isolated artifacts within a single project Norwood, 1979 area—artifacts include flakes, hammerstones,
petrified wood fragments,a chopper,and a
metate.
005792 5792 Prehistoric Site A traditional Indian trail from Mission San Luis Hatley, 1978 Rey through the San Marcos plains to the
Cuyamaca Mountains.
006841 6841 Prehistoric Site Highly disturbed La Jollan site with scattered Fink and midden,shell,and flakes. Hightower,
1978
008246 8246 Prehistoric Site Low to medium density shell and lithic scatter Dittmar, 1980 with associated midden deposit.
020178 --- Historic Address The Charles A. Braun house, built in 1929. Unknown, 1929 024932 16502 Prehistoric Site Habitation site consisting of bedrock milling Strudwick, features, marine shell,and a small amount of McLean, and brownware pottery. Russell, 2003;
Robbins-Wade,
2012
025149 --- Historic Address A one-story single family home built in 1947. Marvin,2003 025150 --- Historic Address A one-story single family residence built in 1948 Marvin,2003 and remodeled in 2002.
025151 --- Historic Address A one and one-half story frame barn built in Marvin,2003 1923.
025152 --- Historic Address A one-story tract residence built in 1954. Marvin,2003 025153 --- Historic Address A one-story residence built in 1950 and Marvin,2003 converted to a commercial use.
025154 --- Historic Address A one-story residence built in 1952 and Marvin,2003 converted to a commercial use.
028770 --- Historic Address A two-story house built in 1929. Marben-Laird Associates,
1987
029304 --- Prehistoric Isolated flake. Ramirez and Isolate Hares,2008
036153 --- Historic A wood-frame building used as a utilitarian Castells,2015 Building. garage and built between 1953 and 1964.
036621 22123 Historic Site Artifact scatter consisting of glass and ceramic Garrison and fragments within two loci. Ellis,2017
036622 --- Historic Address A single-family residence built in the early to Garrison and mid-1900s. Ellis,2017
036623 --- Historic Address A single-family residence built between 1938 Garrison and and 1946. Ellis,2017
038601 --- Historic Road A 560-ft segment of a historic road consisting of Castells,2019 several stretches of asphalt.

HELIX
Environmental Prannrog
14 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Primary Trinomial Age and
Number (CA-SDI-#) Resources Description Recorder,Date (P-374) Present
039086 --- Prehistoric Two isolated pieces of debitage. Pigniolo,2020 Isolate

4.2 OTHER ARCHIVAL RESEARCH
Various archival sources were consulted, including historic topographic maps, aerial imagery(NETR Online 2021), and the Bureau of Land Management (BLM) General Land Office (GLO) Records.These include historic aerials from 1928, 1938, 1946, 1953, 1964, 1967, 1978, and 1980 (NETR Online 2021) and several historic USGS topographic maps, including the 1901 San Luis Rey(1:125,000), 1948, 1968, 1975, and 1997 San Luis Rey (1:24,000)topographic maps.The purpose of this research was to identify historic structures and land use in the area.

No buildings appear in the project site on the 1901 San Luis Rey map,though the Buena Vista Creek is recorded to the north, and the Southern California Rail Road (Escondido Branch) is recorded to the north and northeast of the project area.Additionally, a road is recorded to the south and east of the project area. The 1938 aerial photograph shows Melrose Way to the south of the project area,which appears to have been cleared for agricultural purposes. By the time the 1946 aerial was taken and 1948 San Luis Rey(1:24,000) topographic map was made, an orchard was planted in the area surrounding the property. Additionally, a structure is seen in the southwest corner of the project area on the 1946 and 1947 aerial photographs. A new structure is seen on the 1964 aerial photograph—this structure appears to be the residence that currently exists on the property. By the time this photograph was taken,the orchard on the property had been cleared.The subsequent aerial photographs and topographic maps show the development of the region surrounding the project area.To the south and east of the project area, residential neighborhoods were constructed in the 1970s and 1980s.

According to BLM GLO records,the project area is located within Lot 16 of Section 25, granted to William Larson in 1911, under the authority of the Homestead Entry Original (12 stat. 392) (GLO 1911).

Larson also owned lots 15 and 17 of Section 25 and lot four of Section 26, within Township 11 South, Range 4 West.

4.3 NATIVE AMERICAN CONTACT PROGRAM
HELIX contacted the NAHC on August 19, 2021,for a Sacred Lands File search and a list of Native American contacts for the project area.The NAHC indicated in a response dated September 20, 2021, that the results of the search were positive, and that the La Jolla Band of Luiseno Indians and the San Luis Rey Band of Mission Indians should be contacted for further information. Letters were sent on September 21, 2021, to Native American representatives and interested parties identified by the NAHC.

To date,two written responses have been received; the Rincon Band of Luiseno Indians noted that the project area is within the Territory of the Luiseno people, and within Rincon's Area of Historic Interest.

As such, they requested a copy of this cultural resources assessment for review and comment.

Additionally,the Rincon Band wishes to consult with the City of Vista regarding project impacts to cultural resources.The San Pasqual Band of Mission Indians also responded, noting that while the project area is not within the boundaries of the recognized San Pasqual Indian Reservation, it is within the area which it considers its Traditional Use Area—as such,the Tribe wishes to engage in consultation, and be given access to any cultural resource reports produced for the project.Although the Pechanga HELIX
Environmental Pramnrog
15 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Band of Luiseno Indians (Pechanga) did not provide a written response, Paul Macarro,the Pechanga Cultural Resources Manager, indicated to Principal Investigator, Mary Robbins-Wade, in a conversation on October 20, 2021, that Pechanga would defer to the San Luis Rey Band regarding this project. If any additional responses are received,they will be forwarded to the City of Vista staff. Native American correspondence is included as Appendix C(Confidential Appendices, bound separately).

Ms. Robbins-Wade spoke to Cami Mojado, representing the San Luis Rey Band of Mission Indians, on October 20, 2021, regarding the project and the cultural resources sensitivity of the area. Ms. Mojado indicated that there are a number of known resources in relative proximity to the project site and that cultural material has been encountered during monitoring in the general vicinity.This, combined with the proximity to Buena Vista Creek and the many resources located along that drainage, indicates a sensitivity for buried cultural resources within the project site.Thus, monitoring during ground- disturbing activities should be undertaken.

4.4 FIELD SURVEY
A pedestrian survey of the project site was conducted on August 24, 2021, by HELIX staff archaeologist James Turner and Logovi'i Sialo'i from Saving Sacred Sites.The property was walked in approximately five-meter transects. Much of the southern half of the project area was covered in mulch and bark— visibility in this area was very low, ranging from zero to 15 percent (Plate 1).The northern half was covered in mowed grasses and weeds;visibility here ranged from zero to 30 percent (Plates 2 and 3).

Visible soil, including that produced by rodent burrows, was inspected; this soil consisted of medium and light brown silty sand.

No cultural material was observed within the archaeological survey area; however, as noted above,the project area contained heavily disturbed soils and visibility was poor. ...._ _• .
i
�x > '
'.w '�`� r✓' i x �,.a', -tz- �kE ¢mot ; 'e k"' "�"� .;,: ., Plate 1. Overview of project area from Melrose Way,view to the north.

HELIX
Environmental Aramnrog
16 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Plate 2. Overview of project area from the northeast corner,view to the south.

T'F
14 .e•.. �v ,..�;�`�n.. ., si. -w,-a Yak.. .,.

Plate 3. Overview of northwest corner of the project area,view to the northwest.

5.0 SUMMARY AND MANGEMENT

RECOMMENDATIONS
A study was undertaken to identify cultural resources that are present in the 1205 Melrose Way Project area and to determine the effects of the project on historical resources per CEQA and historic properties per NRHP.The cultural resources survey did not identify any cultural resources within the project area; therefore, no impacts to cultural resources are anticipated.

While the surrounding area remained relatively undeveloped until the 1960s, it has since been highly disturbed by residential development, agricultural activities, utility installations, and road formation.The project area itself has been disturbed by nineteenth and twentieth century agricultural activities, irrigation systems, dirt road formation, and residential development. Much of the project area was cleared for these activities, in particular the agricultural pursuits.

HELIX
Environmental Aramnrog
17 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021

5.1 MANAGEMENT RECOMMENDATIONS
The majority of the project site was covered by mulch and dead grasses, and the original ground surface could not be observed. Based on the results of the current study, no historic properties will be affected by the project. However, it is located within a region rich in cultural resources and the results of the Sacred Lands File Search were positive.Therefore, a grading monitoring program should be implemented for the project.The monitoring program should include the following elements:
• Prior to issuance of grading permits, a pre-excavation agreement shall be developed among the appropriate Native American Tribe(s),the applicant, and the City, as the lead agency; • The qualified archaeologist and the Native American representative(s) shall attend the pre- grading meeting with the contractors to explain the requirements of the monitoring program; • An archaeologist and a Native American monitor shall be on-site during grading, trenching, and other ground-disturbing activities, including brushing/grubbing, unless otherwise agreed upon by the archaeological Principal Investigator,the Native American representative, and City staff; • If cultural resources are encountered, both the archaeologist and the Native American monitor shall have the authority to temporarily halt or redirect grading/trenching while the cultural resources are documented and assessed. If significant resources are encountered, appropriate mitigation measures must be developed and implemented;
• If any human remains are discovered,the County Coroner shall be contacted. In the event that the remains are determined to be of Native American origin, the Most Likely Descendant, as identified by the NAHC, shall be contacted in order to determine proper treatment and disposition of the remains;
• Recovered artifactual materials shall be cataloged and analyzed; • A report shall be completed describing the methods and results of the monitoring and data recovery program; and
• Recovered cultural material shall be curated with accompanying catalog to current professional repository standards or the collection will be returned to the appropriate Native American Tribe(s), as agreed upon by the Principal Investigator, Native American representative(s), and City staff and specified in the pre-excavation agreement. • If cultural material will be returned to the Tribe(s) rather than curated, diagnostic artifacts or particularly good examples of specific tool types, if such are recovered, should be scanned for 3D printing,with the permission of the Tribe(s).The data from 3D scanning would be curated at an appropriate repository, such as the San Diego Archaeological Center.The cultural material can then be returned to the Tribe(s) for reburial or other treatment.

HELIX
Environmental Aramnrog
18 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021

6.0 REFERENCES
Bean, Lowell John, and Florence C. Shipek
1978 Luiseno. In California, edited by Robert F. Heizer, pp. 550-563. Handbook of North American Indians, vol. 8. William C. Sturtevant, general editor.Smithsonian Institution, Washington, D.C.

Beauchamp, R. Mitchell
1986 A Flora of San Diego County, California. Sweetwater River Press, National City.

Boscana, Geronimo
1947 Chinigchinich.A Historical Account of the Origin, Customs, and Traditions of the Indians at the Missionary Establishment of St.Juan Capistrano,Alta-California.Translated by Alfred Robinson. Biobooks, Oakland.

Bull, Charles S.
1983 Shaking the Foundations:The Evidence for San Diego Prehistory. Casual Papers: Cultural Resource Management 1(3):15-64. Cultural Resource Management Center, San Diego State University.

Cameron, Constance
1987 Archaeological Investigations on the Rancho San Clemente, Orange County, California.

Archaeological Research Facility California State University, Fullerton.

Christenson, Lynne N. and Ellen L. Sweet
2008 Images of America:Ranchos of San Diego County. Arcadia Publishing.

City of Vista
N.D. History of Vista. City of Vista. Electronic document available at https://www.cityofvista.com/residents/about-vista/history , accessed December 4, 2020.

Cooley,Theodore G., and Laura J. Barrie
2004 Archaeological Excavation at the Village of Pa'Mu, Ramona Valley, California.

Proceedings of the Society for California Archaeology 17:43-56.

Cupples, Sue Ann, and Ken Hedges
1977 San Luis Rey River Basin: Overview of Cultural Resources. San Diego State University Foundation. Prepared for US Army Corps of Engineers. Electronic document, available at http://www.dtic.mil/dtic/tr/fulltext/u2/al46300.pdf , accessed September 9, 2021.

DuBois, Constance
1908 The Religion of the Luiseno Indians of Southern California. University of California Publications in American Archaeology and Ethnology 8(3):69-186.

HELIX
Environmental Aramnrog
19 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Ezell, Paul H.
1987 The Harris Site—An Atypical San Dieguito Site, or Am I Beating a Dead Horse? In San Dieguito—La Jolla: Chronology and Controversy, edited by Dennis Gallegos, pp. 15-22.

San Diego County Archaeological Society Research Paper Number 1. San Diego.

Gallegos, Dennis
1987 A Review and Synthesis of Environmental and Cultural Material for the Batiquitos Lagoon Region. In San Dieguito-La Jolla: Chronology and Controversy, edited by Dennis Gallegos, pp. 23-34. San Diego County Archaeological Society, Research Paper 1.

GLO (General Land Office)
1911 Land Patent 03827: Larson, William. September 28.

Kennedy, Michael P., and Siang S.Tan
2007 Geologic Map of the Oceanside 30 x 60-Minute Quadrangle, California. Digital preparation by Kelly R. Bovard, Rachel M. Alvarez, Michael J. Watson, and Carlos I.

Gutierrez. California Department of Conservation, California Geological Survey.

Kroeber,A.L.
1976 Handbook of California Indians. Dover, New York. Originally published 1925 as Bulletin 78 of the Bureau of American Ethnology of the Smithsonian Institution.

Kyle, Carolyn E., Roxana L. Phillips, and Dennis R. Gallegos 2000 Cultural Resource Survey for the Proposed State Route 78/Rancho del Oro Interchange Project, City of Oceanside, California. Gallegos&Associates, Carlsbad, CA. Report on file at South Coastal Information Center, San Diego State University.

Laylander, Don, and Lynne E. Christenson
1988 Results of an Archaeological Data Recovery Program, Corral Canyon Prehistoric Archaeological District, San Diego County, California. Report prepared for, and on file at, the Cleveland National Forest, Supervisor's Office, San Diego.

Lightfoot, Kent G.
2004 Indians, Missionaries, and Merchants: The Legacy of Colonial Encounters on the California Frontiers. University of California Press, Berkeley, CA.

Marben-Laird Associates
1987 Historic Resource Survey,A Project of the City of Vista, California. Report submitted to City of Vista. Report on file at South Coastal Information Center, San Diego State University.

Masiel-Zamora, Myra Ruth
2013 Analysis of'Exva Temeeku,A Luiseno Indian Village Site Named Temeku, Located in Temecula, California. Master's thesis, Department of Anthropology, San Diego State University.

HELIX
Environmental Aramnrog
20 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 McCown, B.E.
1955 Temeku.A Page from the History of the Luiseno Indians. Archaeological Survey Association of Southern California Paper No. 3.

Meighan, C.W.
1954 A Late Complex in Southern California Prehistory. Southwestern Journal of Anthropology 10(2):215-227.

Mikesell, Stephen D.
2000 Historic Architectural Survey Report Rancho Del Oro/Route 781nterchange Project.JRP Historical Consulting Services, Davis, CA. Report on file at South Coastal Information Center, San Diego State University.

Moratto, Michael J.
1984 California Archaeology.Academic Press, Orlando.

Moriarty,James R., III
1966 Cultural Phase Divisions Suggested by Typological Change Coordinated with Stratigraphically Controlled Radiocarbon Dating in San Diego.The Anthropological Journal of Canada 4 (4):20-30.

Moyer, Cecil C.
1969 Historic Ranchos of San Diego. Union Tribune Publishing Company, San Diego, CA.

Munz, Philip A.
1974 A Flora of Southern California. University of California Press, Berkeley.

Natural Resources Conservation Service
1997a Placentia Series. United States Department of Agriculture. Electronic document available at: https://soiIseries.sc.egov.usda.gov/OSD Docs/P/PLACENTIA.html, accessed on September 9, 2021.
1997b Bosanko Series. United States Department of Agriculture. Electronic document available at: https://soiIseries.sc.egov.usda.gov/OSD Docs/B/BOSANKO.html, accessed on September 9, 2021.

NETR Online
2021 Historic Aerials. Nationwide Environmental Title Research, LLC. Electronic document available at: http://www.historicaerials.com , accessed September 9, 2021.

Parker, Patricia L. and Thomas F. King
1998 Guidelines for Evaluating and Documenting Traditional Cultural Properties. National Park Service, Washington, D.C.

HELIX
Environmental Aramnrog
21 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Raven-Jennings, Shelly, and Brian F. Smith
1999 Report of Excavations at CA-SDI-4608: Subsistence and Technology Transitions during the Mid-to-Late Holocene in San Diego County. Brian F. Smith and Associates. Report prepared for the City of Poway. Report on file at the South Coastal Information Center, San Diego State University.

Robinson,Alfred
1947 Life in California. Biobooks, Oakland.

Rogers, Malcolm J.
1939 Early Lithic Industries of the Lower Basin of the Colorado River and Adjacent Desert Areas. San Diego Museum of Man Papers No. 3. San Diego Museum of Man.

Rosenberg, Seth A.,Adriane Dorrler, and Brian F. Smith
2007 A Cultural Resources Evaluation for the Vista and Buena Sanitation District 2007 Sewer Master Plan Update. Brian F. Smith and Associates. Report on file at South Coastal Information Center, San Diego State University.

Rush, Philip S.
1965 Some Old Ranchos and Adobes. Neyenesch Printers, Inc., San Diego.

Shipek, Florence C.
1977 A Strategy for Change.The Luiseno of Southern California. Ph.D. dissertation, University of Hawaii. University Microfilms International,Ann Arbor, Michigan.

Sparkman, Philip Stedman
1908 The Culture of the Luiseno Indians. University of California Publications in American Archaeology and Ethnology 8(4):187-234.

Talley, R. Paige
1982 The Life History of a Luiseno Indian:James (Jim) Martinez. Unpublished Master's thesis, Department of Anthropology, San Diego State University.

True, D. L.
1958 An Early Complex in San Diego County, California. American Antiquity 23(3): 255-263. 1970 Investigation of a Late Prehistoric Complex in Cuyamaca Rancho State Park, San Diego County, California. Monograph 1.Archaeological Survey, University of California, Los Angeles.
1980 The Pauma Complex in Northern San Diego County: 1978.Journal of New World Archaeology 3(4): 1-30. Institute of Archaeology, University of California, Los Angeles.

True, D.L., C.W. Meighan, and Harvey Crew
1974 Archaeological Investigations at Molpa, San Diego County, California. University of California Publications in Anthropology,Vol 11.

Vista Historical Society
2020 Vista History. Electronic document available at https://vistahistoricalsociety.com/about/vista-history?showall=l , accessed September 9, 2021.

HELIX
Environmental Aramnrog
22 Cultural Resource Survey for the 1205 Melrose Way Project I October 2021 Wallace, William J.
1955 A Suggested Chronology for Southern California Coastal Archaeology.Southwestern Journal of Anthropology 11:214-230.
1960 Archaeological Resources of the Buena Vista Watershed, San Diego County, California.

University of California, Los Angeles Archaeological Survey Annual Report 1959- 1960:277-300.

Warren, Claude N.
1967 The San Dieguito Complex:A Review and Hypothesis.American Antiquity 32:168-185. 1968 Cultural Tradition and Ecological Adaptation on the Southern California Coast. In Archaic Prehistory in the Western United States, edited by C. Irwin-Williams, pp. 1-14. Eastern New Mexico Contributions in Anthropology 1(3). Portales, New Mexico.

Warren, Claude N., Gretchen Siegler, and Frank Dittmer
1998 Paleoindian and Early Archaic Periods. In Prehistoric and Historic Archaeology of Metropolitan San Diego: A Historic Properties Background Study. Draft. ASM Affiliates.

Report submitted to Metropolitan Wastewater, San Diego.

White, Raymond C.
1963 Luiseno Social Organization. University of California Publications in American Archaeology and Ethnology 48(2):91-194.

Young, Stanly and Melba Levick
1988 The Missions of California. Chronical Books LLC, San Francisco, CA HELIX
Environmental Aramnrog
23 Appendix A
Resumes

V � I / -
ironmental Planning
James Turner, RPA
Staff Archaeologist
a a \/
Summre ualli
Mr. Turner is a Registered Professional Archaeologist(RPA)with a Master's degree in Educa ion Anthropology and field and college-level teaching experience in archaeology. He is Master of Arts, experienced in Section 106, the Native American Graves Protection and Repatriation Anthropology, San Act (NAGPRA), and writing detailed reports. Mr. Turner has archaeological research Diego State and fieldwork expertise throughout southern California. He has also received training University, 2018 in identifying and analyzing animal remains in archaeological contexts, historic artifact Bachelor of Arts, identification, and technical writing. Mr. Turner's experience meets the Secretary of Biology and the Interior's Professional Qualification Standards for archaeology. Anthropology, San Diego State
University, 2015
Selec ed Pro ec E perience
e S 434 old Mine Moni orin (2020). Archaeologist for an erosion control and repair project in the community of Julian. Conducted cultural resource monitoring a is ra ions and report preparation. Work performed for San Diego Gas & Electric. Cer i ica ions Registered
Aliso Cree Can on es ora ion Pro ec (2020). Archaeologist for an erosion Professional repair project in Lake Forest. Conducted a field survey of the project area, performed Archaeologist#17338 background research, and produced a cultural resources report. Work performed for the Orange County Department of Public Works.

Pro essional
roadwa C annel Improvemen s - P ase A (2020 - ). Archaeologist for an A ilia ions earthen channel improvement project in the city of El Cajon. Performed background Society for Historical research and prepared cultural resource survey report. Work performed for City of El Archaeology Cajon. Society for California
Archaeology
Clairemon Communi Plan pda a El P 1 (2020). Archaeologist for the Clairemont Community Plan Update. Performed background research and assisted with preparing the Community Plan Update cultural resources section. Work performed for the City of San Diego.

Cordial oad Pipeline (2020). Archaeologist for a pipeline replacement project in the unincorporated portion of the City of El Cajon. Performed background research and field survey. Other responsibilities included the production of a letter report detailing the methods and results of the survey, as well as the completion of a site record update to submit to the South Coastal Information Center. Work performed for the Padre Dam Municipal Water District.

Carmel Moun ain oad Li a Sciences Pro ec (2020). Archaeologist for a proposed commercial development project in the Torrey Hills Community Plan area.

James Turner, RPA
Staff Archaeologist
Responsibilities included performing background and archival research and producing an archaeological resources report. Work performed for Allen Matkins Leck Gabme Mallory& Natsis, LLP.

Dra EIS Overseas EIS - Disposal o Decommissioned, De ueled E -En erprise CV 6 Associa ed aval eac or Plan s (2020 - ). Archaeologist for the Draft EIS for the disposal of the Navy ex-Enterprise. Responsible for background research and citation management and assisted with document preparation. Work performed for the United States Navy as a subconsultant to ManTech.

Eas la a Villa a Par (2020). Archaeologist for a telecommunication project in the community of Eastlake in the City of Chula Vista. Conducted cultural resource monitoring for the drilling of a cassion hole. Work performed for Terracon. eneral Coa in s (2020). Archaeologist for a due diligence project for the possible future expansion of the General Coatings property. Conducted background research, which included analyzing a records search and viewing historic maps and aerial photographs of the project area. Additional responsibilities included performing a field survey of the project area and producing a cultural resources due diligence report.

Work performed for General Coatings.

La a anc o Vie o Environmen al Consul in (2020). Archaeologist for a cultural resources survey for a proposed housing development in the community of Fallbrook in northern San Diego County. Conducted background research and report preparation. Work performed for Q Technology Direct LLC with County of San Diego as the lead agency.

M n View Connec or Pipeline -Cul ural (2020). Archaeologist for a waterline replacement project in the community of Alpine. Conducted cultural resource monitoring and prepared the final monitoring report. Work performed for Padre Dam Municipal Water District.

Sal a Des! n Dis ric Spec! is Plan El (2020). Archaeologist for a mixed-use development project, which proposes to include wholesale/retail shopping and light industrial uses. Participated in an archaeological testing program and produced artifact tables for report. Work performed for M &A Gabaee.

San a sa el rail (2020 - ). Staff Archaeologist for a proposed 3 mile hiking trail in the unincorporated community of Julian. Performed background research, participated in the cultural resource survey, and contributed to the cultural resources survey report. Work performed for the County of San Diego Parks and Recreation Department.
2 A fit
tal Planning Ent

FBI / - i
ironmental Planning
Mary Robbins-Wade, RPA
Cultural Resources Group Manager
mammary of Qualifications
Ms. Robbi wAVade4 a&44-years of extea ivP Pxperience in both archaeological research and general environmental studies. She oversees the management of all Education archaeological, historic, and interpretive projects; prepares and administers budgets Master of Arts, and contracts; designs research programs; supervises personnel; and writes reports. Anthropology, San Ms. Robbins-Wade has managed or participated in hundreds of projects under the Diego State California Environmental Quality Act (CEQA), as well as numerous archaeological University, California, studies under various federal jurisdictions, addressing Section 106 compliance and 1990 National Environmental Policy Act(NEPA) issues. She has excellent relationships Bachelor of Arts, with local Native American communities and the Native American Heritage Anthropology, Commission (NAHC), as well as has supported a number of local agency clients with University of Native American consultation under State Bill 18 and assistance with notification and California, Santa Native American outreach for Assembly Bill 52 consultation. Ms. Robbins-Wade is a Barbara, 1981 Registered Professional Archaeologist(RPA)and meets the U.S. Secretary of the Interior's Professional Qualifications for prehistoric and historic archaeology.

Registrations/
Selected Project Experience Certifications Caltrans,
12 Oaks Winery Resort. Project Manager/ Principal Investigator for a cultural Professionally resources survey of approximately 650 acres for a proposed project in the County of Qualified Staff- Riverside. Oversaw background research, field survey, site record updates, Native Equivalent Principal American coordination, and report preparation. Met with Pechanga Cultural Investigator for Resources staff to discuss Native American concerns. Worked with applicant and prehistoric Pechanga to design the project to avoid impacts to cultural resources. Work archaeology, performed for Standard Portfolio Temecula, LLC. , Bureau of Land Management
Statewide Cultural
28th Street between Island Avenue and Clay Avenue Utilities Undergrounding Resource Use Permit Archaeological Monitoring. Project Manager/Principal Investigator for a utilities (California), permit undergrounding project in a historic neighborhood of East San Diego. Responsible #CA-18-35, for project management; coordination of archaeological and Native American , Register of monitors; coordination with forensic anthropologist, Native American Professional representative/Most Likely Descendent, and City staff regarding treatment of possible Archaeologists human remains; oversaw identification of artifacts and cultural features, report #10294, 1991 preparation, and resource documentation. Work performed for the City of San Diego. County of San Diego, Approved CEQA
Archaeological Testing F11 Project. Project Manager for a cultural resources study Consultant for for a proposed mixed-use commercial and residential tower in downtown San Diego. Archaeological Initial work included an archaeological records search and a historic study, including Resources, 2007 assessment of the potential for historic archaeological resources. Subsequent work , Orange County included development and implementation of an archaeological testing plan, as well Approved �rrhoonlnnic+ `)(19R
as construction monitoring and the assessment of historic archaeological resources encountered. Work performed for the Richman Group of Companies.

Mary Robbins-Wade, RPA
Cultural Resources Group Manager
Blended Reverse Osmosis (RO) Line Project. Project Manager/ Principal Investigator for cultural resources monitoring during construction of a 24-inch recycled water pipeline in the City of Escondido.

Oversaw monitoring program, including Worker Environmental Awareness Training; responsible for Native American outreach/coordination, coordination with City staff and construction crews, and general project management. Work performed for the City of Escondido.

Buena Sanitation District Green Oak Sewer Replacement Project. Project Manager/Principal Investigator for a cultural resources testing program in conjunction with a proposed sewer replacement project for the City of Vista. Oversaw background research, fieldwork, site record update, Native American coordination, and report preparation. Work performed for Harris &Associates, Inc., with the City of Vista as the lead agency.

Cactus II Feeder Transmission Pipeline IS/MND. Cultural Resources Task Lead for this project in the City of Moreno Valley. Eastern Municipal Water District proposed to construct approximately five miles of new 30-inch to 42 inch-diameter pipeline; the project would address existing system deficiencies within the City and provide supply for developing areas. Oversaw background research, field survey, and report preparation. Responsible for Native American outreach for cultural resources survey. Assisted District with Native American outreach and consultation under AB 52. Work performed under an as-needed contract for Eastern Municipal Water District.

Dale 2199C Pressure Zone Looping Pipeline Project. Cultural Resources Task Lead for this project in Moreno Valley. Eastern Municipal Water District proposed construction of a new pipeline to connect two existing pipelines in the District's 2199C Pressure Zone. The pipeline would consist of an 18-inch- diameter pipeline between Kitching Street and Alta Vista Drive that would connect to an existing 12-inch- diameter pipeline in the northern end of Kitching Street and to an existing 18-inch-diameter pipeline at the eastern end of Alta Vista Drive. The project will improve reliability and boost the Dale Pressure Zone's baseline pressure and fire flow availabilities. Four potential alignments were under consideration; three of these bisect undeveloped land to varying degrees, while the other is entirely situated within developed roadways. Oversaw background research and field survey. Responsible for Native American outreach for cultural resources survey and co-authored technical report. Work performed under an as-needed contract for Eastern Municipal Water District.

Downtown Riverside Metrolink Station Track& Platform Project. Cultural Resources Task Lead for this project involving changes to and expansion of the Downtown Riverside Metrolink Station.

Overseeing records search and background information, archaeological survey, and report preparation.

Responsible for coordination with Native American Heritage Commission, Riverside County Transportation Commission (RCTC), and Federal Transportation Authority(FTA) on Native American outreach. Work performed for Riverside County Transportation Commission as a subconsultant to HNTB Corporation.
2 rit
tal Planning Ent

Appendix B
Records Search Results
(Confidential, Bound Separately)

Appendix C
Native American Correspondence
(Confidential, Bound Separately)

PRELIMINARY GEOTECHNICAL INVESTIGATION,
PROPOSED 15-LOT SUBDIVISION
f' 1205 MEiROF WAY,VISTA
SAN D CO N Y, CA RNIA 2081
'K s -

Z RAN DJORDJEVICH
551 LYNWOOD DRIVE
ENCINITAS, CALIFORNIA 92024
W.O. 8058-A-SC MARCH 5, 2021

'Is,
Geotechnical • Geologic • Coastal • Environmental
5741 Palmer Way • Carlsbad, California 92010 • (760) 438-3155 • FAX (760) 931-0915 • www.geosoilsinc.com March 5, 2021
W.O. 8058-A-SC
Mr. Zoran Djordjevich
551 Lynwood Drive
Encinitas, California 92024
Subject: Preliminary Geotechnical Investigation, Proposed 15-Lot Subdivision, 1205 Melrose Way, Vista, San Diego County, California 92081, APNs 166-184-10-00 & 166-183-17-00
Dear Mr. Djordjevich:

In accordance with your request and authorization, GeoSoils, Inc. (GSI) is pleased to present the results of our preliminary geotechnical investigation of the subject site. The purpose of our study was to evaluate the site geologic and geotechnical conditions in order to develop preliminary recommendations for earthwork and the design of foundations, walls, and pavements, as they relate to the proposed subdivision at the subject property.

EXECUTIVE SUMMARY
Based upon our field exploration, geologic, and geotechnical engineering analysis, the proposed development is considered feasible from a geotechnical engineering and geologic viewpoint, provided that the recommendations presented in the text of this report are properly incorporated into the design and construction of the project. The most significant elements of our study are summarized below:
• In general, the site is characterized as being underlain by Cretaceous-age granitic bedrock belonging to the Southern California Batholith, with a relatively thin layer of Quaternary-age colluvium (topsoil) at the surface. Although not directly encountered during field explorations, localized undocumented artificial fill is likely associated with the existing residence.
• Due to their relatively low density, lack of uniformity, and porous nature, all undocumented artificial fill, colluvium, and highly weathered granitic bedrock (if encountered) are considered potentially compressible and unsuitable for the support of settlement-sensitive improvements (i.e., the residential foundation, the concrete slab-on-grade floors, site walls, underground utilities, the driveway pavement, exterior hardscape, etc.) and/or engineered fill in their existing state.

Based on the available data, the thickness of potentially compressible soils across the site is anticipated to vary up to approximately 2 to 4 feet. However, localized thicker sections of unsuitable soils cannot be precluded and should be anticipated,

especially within the existing sewer and water easement. Conversely, any underlying granitic bedrock, that is not highly weathered, is considered suitable for the support of settlement-sensitive improvements and engineered fill. • In order to: 1) facilitate excavations for the currently proposed and future site improvements; 2) mitigate the potential for water vapor transmission through floor slabs; and 3) provide forthe uniform support of structures; areas of the building pad where the planned plus remedial fill thickness does not provide for at least 3 feet of compacted fill below pad grade or 24 inches of compacted fill below the lowest foundation element (whichever is greater) should be overexcavated (undercut),and then brought to the design grades with suitable, compacted fill soil. Consideration may be given to overexcavating the street area to facilitate utility construction, however,this is not a geotechnical requirement. Overexcavation recommendations are presented herein.
• The 2019 California Building Code ([2019 CBC], California Building Standards Commission [CBSC], 2019) indicates that removals of unsuitable soils be performed across all areas to be graded, under the purview of the grading permit, not just within the influence of the residential structure. Relatively deep removals may also necessitate a special zone of consideration, on perimeter/confining areas.

This zone would be approximately equal to the depth of removals, if removals cannot be performed onsite or offsite. In general, any planned improvement located above a 1 :1 (horizontal:vertical [h:v]) projection up from the bottom, outboard edge of the remedial grading excavation at the subdivision boundary would be affected by perimeter conditions. On a preliminary basis, any planned settlement-sensitive improvement located within approximately 2 to 4 feet from the site boundary would require deepened foundations or additional reinforcement by means of ground improvement or specific structural design. Otherwise these improvements may be subject to distress and a reduced service life. This will also require proper disclosure to all interested/affected parties should this condition exist at the conclusion of grading.
• Current laboratory testing indicates that some of the onsite sandy soils exhibit expansion index values less than 21. However, the onsite clayey soils exhibit a plasticity index (PI) of 32. As such, some site soils appear to meet the criteria for detrimentally expansive soils as defined in Section 1803.5.3 of the 2019 CBC (CBSC, 2019a). Residential building foundations within the influence of expansive soils should be designed and constructed in accordance with Sections 1808.6.1 or 1808.6.2 of the 2019 CBC.
• Corrosion testing performed on a representative sample of the onsite soils indicates that the sample is neutral with respect to soil acidity/alkalinity, corrosive to exposed buried metals when in a saturated state, presents negligible sulfate exposure to concrete, and exhibits low chloride exposure. Additional comments may be obtained from a corrosion engineer, depending on the level of protection required, Mr. Zoran Djordjevich W.O. 8058-A-SC
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as determined by the Project Civil Engineer, Project Structural Engineer, and/or Project Architect.
• The removal and recompaction of potentially compressible soils below a 1 :1 (h:v) plane projected down from the bottom, outside of planned settlement-sensitive improvements and fill along the perimeter of the site will be limited due to boundary restrictions. As such, any settlement-sensitive improvement located above a 1 :1 (h:v) plane projected up from the bottom outboard edge of the remedial grading excavation at the property line would require deepened foundations below this plane, additional reinforcement, or would retain some potential for distress and therefore, a reduced service life.
• Neither the regional groundwater table nor perched water was encountered during our subsurface studies to the depth explored. As such, regional groundwater is not anticipated to significantly affect the planned improvements. Perched water may occur in the future along zones of contrasting permeability and/or density, or seepage may occur along bedrock joints and fractures. Perched groundwater can be shallow on sites underlain by similar geologic conditions. This potential should be disclosed to all interested/affected parties.
• Our evaluation indicates there are no known active faults crossing the site and the natural slope upon which the site is located has very low susceptibility to deep-seated landslides. Owing to the depth to groundwater and the dense nature of the granitic bedrock, the potential for the site to be adversely affected by liquefaction/lateral spreading is considered very low. Some of the site soils are considered erosive due to low cohesive properties. Thus, properly designed and maintained site drainage is considered necessary in reducing erosion damage to the planned improvements.
• The seismic acceleration values and design parameters provided herein should be considered during the design of the proposed development. The adverse effects of seismic shaking on the structure will likely be wall cracks, some foundation/slab distress, and some seismic settlement. However, it is anticipated that the proposed structure will be repairable in the event of the design seismic event. This potential should be disclosed to all interested/affected parties. • A "desk top" review of storm water infiltration indicates that a no infiltration design is recommended, owing to the potential to cause distress to existing and proposed improvements.
• Additional adverse geologic features that would preclude project feasibility were not encountered, based on the available data.
• The recommendations presented in this report should be incorporated into the design and construction considerations of the project.

Mr. Zoran Djordjevich W.O. 8058-A-SC
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The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to contact our office.

Respectfully submitt 55�QNAL FR'�NO�O o4PpFESS/ONE 4 GeoSoils, Inc. a ' No. 134o
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Enginefeering No. RCE 47857
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ohn . Franklin OF CA
David W. ell
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Engineering Geologist, CEG 1340 Civil Engineer, RCE 47 MJS/JPF/DWS/mn
Distribution: (3) Addressee (2 wet signed and PDF via email) Mr. Zoran Djordjevich W.O. 8058-A-SC
File:e:\wp12\8000\8058a.gep GeoSoils, Inc. Page Four

TABLE OF CONTENTS
SCOPE OF SERVICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SITE DESCRIPTION AND PROPOSED DEVELOPMENT . . . . . . . . . . . . . . . . . . . . . . . . . 1 FIELD STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 REGIONAL GEOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 SITE GEOLOGIC UNITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Undocumented Artificial Fill (Map Symbol - Afu) . . . . . . . . . . . . . . . . . . . . 4 Quaternary Colluvium (Map Symbol - Qcol) . . . . . . . . . . . . . . . . . . . . . . . 4 Cretaceous Granitic Bedrock (Map Symbol - Kt) . . . . . . . . . . . . . . . . . . . . 4 Structural Geology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 GROUNDWATER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 FAULTING AND REGIONAL SEISMICITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Regional Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Local Faulting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Seismicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Seismic Shaking Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 GEOLOGIC HAZARDS EVALUATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Mass Wasting/Landslide Susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 SECONDARY SEISMIC HAZARDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 LABORATORY TESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Moisture-Density Relations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Expansion Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Atterberg Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Laboratory Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Direct Shear Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Saturated Resistivity, pH, and Soluble Sulfates, and Chlorides . . . . . . . . . . . . . 11 Corrosion Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 STORM WATER TREATMENT AND HYDROMODIFICATION MANAGEMENT . . . . . . . 11 USDAStudy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Infiltration Feasibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Onsite Infiltration-Runoff Retention Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . 14 GeoSoils, Inc.

EARTHWORK CONSTRUCTION RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . 17 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Site Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Removal and Recompaction of Potentially Compressible Earth Materials . . . . 17 Perimeter Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Overexcavation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Alternating Slot Excavations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 FillPlacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 ImportSoils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Graded Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Temporary Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Earthwork Balance (Shrinkage/Bulking) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 PRELIMINARY RECOMMENDATIONS - FOUNDATIONS . . . . . . . . . . . . . . . . . . . . . . . 21 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Expansive/Corrosive Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Preliminary Foundation Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 PRELIMINARY FOUNDATION CONSTRUCTION RECOMMENDATIONS . . . . . . . . . . . 23 Stiffened Slabs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Structural Mat Foundations - Design/Construction . . . . . . . . . . . . . . . . . . . . . . . 25 Post Tension Slab Foundation Design/Construction . . . . . . . . . . . . . . . . . . . . . 26 Slab Subgrade Pre-Soaking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Perimeter Cut-Off Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Post-Tensioned Foundation Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Soil Support Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Confirmation Testing for Final Foundation Design . . . . . . . . . . . . . . . . . . . . . . . 29 SOIL MOISTURE TRANSMISSION CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . 30 WALL DESIGN PARAMETERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Conventional Retaining Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Preliminary Retaining Wall Foundation Design . . . . . . . . . . . . . . . . . . . . 32 Restrained Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Cantilevered Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Seismic Surcharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Retaining Wall Backfill and Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Wall/Retaining Wall Footing Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS . . . . . . . . . . . . . . . . . . . . . . . 39

PRELIMINARY ASPHALTIC CONCRETE
PAVEMENT DESIGN RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 PAVEMENT GRADING RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 GeoSoils, Inc.

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Subgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Aggregate Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Paving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 PCC Cross Gutters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Additional Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 DEVELOPMENT CRITERIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Slope Maintenance and Planting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Erosion Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Landscape Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Gutters and Downspouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Subsurface and Surface Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Site Improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 TileFlooring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Additional Grading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Footing Trench Excavation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Trenching/Temporary Construction Backcuts . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Utility Trench Backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

SUMMARY OF RECOMMENDATIONS REGARDING
GEOTECHNICAL OBSERVATION AND TESTING . . . . . . . . . . . . . . . . . . . . . . . 47 OTHER DESIGN PROFESSIONALS/CONSULTANTS . . . . . . . . . . . . . . . . . . . . . . . . . . 48 PLAN REVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Rock Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 FIGURES:

Figure 1 - Site Location Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Detail 1 - Typical Retaining Wall Backfill and Drainage Detail . . . . . . . . . . . . . . 37 Detail 2 - Retaining Wall Backfill and Subdrain Detail Geotextile Drain . . . . . . . 38 Detail 3 - Retaining Wall and Subdrain Detail Clean Sand Backfill . . . . . . . . . . . 39 ATTACHMENTS:

Appendix A - References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear of Text Appendix B - Boring Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear of Text Appendix C - Seismicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear of Text Appendix D - Laboratory Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear of Text Appendix E - Storm Water BMP Checklists/Forms . . . . . . . . . . . . . . . Rear of Text Appendix F - General Earthwork, Grading Guidelines,
and Preliminary Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear of Text Plate 1 - Geotechnical Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear of Text GeoSoils, Inc.

PRELIMINARY GEOTECHNICAL EVALUATION,
PROPOSED 15-LOT SUBDIVISION
1205 MELROSE WAY, VISTA
SAN DIEGO COUNTY, CALIFORNIA 92081
APNs 166-184-10-00 & 166-183-17-00

SCOPE OF SERVICES
GSI has provided the following services for the geotechnical evaluation of the subject site. • Reviews of available published literature, maps, and aerial photos of the vicinity(see Appendix A).
• Geologic site reconnaissance, mapping, and subsurface exploration with four (4) hand-powered auger borings (see Appendix B).
• General geologic hazards and areal seismicity evaluations (see Appendix C). • Laboratory testing of collected soil samples (see Appendix D). • A "Desktop" infiltration feasibility study (see Appendix E). • Analysis of field and laboratory data relative to the proposed development. • Preparation of this appropriately illustrated preliminary geotechnical report.

SITE DESCRIPTION AND PROPOSED DEVELOPMENT
The subject site is a panhandle-shaped property consisting of two parcels located at 1205 Melrose Way, in the City of Vista, San Diego County, California (see Figure 1 , Site Location Map). The geographic coordinates of the approximate centroid of the property area under review are 33.1854, -117.2569. The subject site consists of a one-story, single-family residence, with an asphaltic concrete driveway, a CMU block wall along the eastern property line, minor hardscaping, and a few sparse trees, shrubs, and boulders throughout the property. The site is bounded by Melrose Way to the south, a church and parking lot to the east, multi-family residential buildings to the north/northeast, and by existing relatively-undeveloped residential properties to the remaining quadrants. The property slopes gently to the north/northeast, and based on the site plan prepared by Pasco Laret Suiter & Associates (PLSA, 2020), existing elevations across the site range from about 371 feet mean sea level (MSL) near the southwest corner, to 354 feet MSL near the northeast corner, resulting in an overall relief of ±17 feet in the study area. Existing site drainage appears to be accommodated by topographic sheet flow runoff directed toward the north, generally through small meandering channels trending north/northeast.

Vegetation generally consists of seasonal grasses, with sparse trees and shrubs located around the existing residence.

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SITE LOCATION MAP
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Based on our review of PLSA(2020), it is our understanding that the site is proposed to be subdivided into 15 individual residential lots, with the existing residence to be razed. It appears that access to the residences will occur through the use of a planned private road cul-de-sac and shared driveway. Cut and fill grading appears necessary to achieve design grades with maximum planned cuts and fills anticipated to be on the order of ±3 to 5 feet.

Architectural and grading plans have not yet been provided for GSI review. However, we anticipate that the proposed residence will be one (1) to two (2) stories, comprised of a wooden frame, and supported by typical shallow foundations with a slab-on-grade floor.

FIELD STUDIES
Site-specific field studies were conducted by GSI in February 2021, and consisted of reconnaissance geologic mapping, and advancing four (4) exploratory borings, with a hand-powered auger, for an evaluation of the onsite subsurface conditions. The borings were logged by a representative of this office who collected representative bulk and undisturbed soil samples for appropriate laboratory testing. The logs of the borings are presented in Appendix B. The approximate location of the borings completed on the subject site are presented on the Geotechnical Map, which uses PLSA (2020) as a base (see Plate 1).

REGIONAL GEOLOGY
The subject property lies within the coastal plains physiographic region of the Peninsular Ranges Geomorphic Province of Southern California. This region consists of dissected, mesa-like terraces that transition inland to rolling hills. The encompassing Peninsular Ranges Geomorphic Province is characterized as elongated mountain ranges and valleys that trend northwesterly (Norris and Webb, 1990). This geomorphic province extends from the base of the east-west aligned Santa Monica-San Gabriel Mountains,and continues south into Baja California. The mountain ranges within this province are underlain by basement rocks consisting of pre-Cretaceous metasedimentary rocks, Jurassic metavolcanic rocks, and Cretaceous plutonic (granitic) rocks.

In the Southern California region, deposition occurred during the Cretaceous Period and Cenozoic Era in the continental margin of a forearc basin. Sediments, derived from Cretaceous-age plutonic rocks and Jurassic-age volcanic rocks,were deposited during the Tertiary Period (Eocene-age) into the narrow, steep, coastal plain and continental margin of the basin. These rocks have been uplifted, eroded, and deeply incised. During early Pleistocene time, a broad coastal plain was developed from the deposition of marine terrace deposits (currently termed "paralic deposits"). During mid-to late Pleistocene time, this plain was uplifted, eroded and incised. Alluvial deposits have since filled the lower valleys, and young marine sediments are currently being deposited/eroded within coastal and beach areas. Regional geologic mapping by Kennedy and Tan (2007) indicates the site is underlain by Cretaceous-age granitic bedrock of tonalite composition.

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SITE GEOLOGIC UNITS
General
The geologic units observed and/or encountered at the subject site consisted of Quaternary-age colluvium (topsoil) and granitic bedrock exhibiting varying degrees of weathering. A general description of each soil type is presented as follows,from youngest to oldest.

Undocumented Artificial Fill (Map Symbol - Afu)
Although not encountered in our explorations during the study,the southwest corner of the property and an area within the northwest corner of the property, appeared to contain undocumented fill, likely associated with the development of the existing residence and offsite improvements. Based on the surficial appearance and classification, these fill soils appeared to have been locally derived and consisted of moist, soft, dark olive brown and gray brown silty clay with construction debris. As a result of the potentially compressible nature of these soils,they are considered unsuitable for the support of settlement sensitive structures and/or improvements in their existing state.These materials should be removed, moisture-conditioned, and recompacted and/or processed in place, should settlement-sensitive improvements be proposed.

Quaternary Colluvium (Map Symbol - Qcol)
As observed, existing colluvium was encountered in each of our explorations as a surficial layer (or below organic mulch) with a thickness ranging from ±11/2 to ±4 feet. Where observed, colluvium generally consisted of a dark brown, dark olive brown, and dark to moderate reddish brown silty/sandy clay, with occasional areas of silty sand, both consisting of mostly fine to coarse grained sand. The colluvium was typically noted as damp to moist, soft to medium stiff/dense, having low visible porosity, and containing sporadic subangular gravels. All colluvium is considered potentially compressible and prone to settlement under loading in its existing state. As such, it should not be used for the support of settlement-sensitive improvements and/or any planned fills, unless adequately remediated.

Cretaceous Granitic Bedrock (Map Symbol - Kt)
Granitic bedrock of tonalite composition was encountered at relatively shallow depths of roughly 11/2 to 4 feet below the existing grades. The granitic bedrock exhibited varying degrees of weathering in some of our borings. The weathered granitic bedrock encountered in our borings generally disintegrated to gray, pale yellow, light yellowish brown, and very light to dark reddish brown silty sand and clayey sand. This weathered bedrock was typically observed as dry to moist, medium dense to very dense, and containing relic bedrock structure and fragments. The granitic bedrock encountered is Mr. Zoran Djordjevich W.O. 8058-A-SC
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considered suitable for the support of fills and settlement-sensitive improvements in its existing state.

Structural Geology
No adverse geologic structures were observed on the site; the granitic bedrock and typically displays high angle fractures/joints.

GROUNDWATER
GSI did not observe evidence of a regional groundwater table nor perched water within our subsurface explorations. Therefore, regional groundwater is not anticipated to significantly affect proposed site development, provided that the recommendations contained in this report are properly incorporated into final design and construction. These observations reflect site conditions at the time of our investigation and do not preclude future changes in local groundwater conditions from excessive irrigation, precipitation, or that were not obvious, at the time of our investigation.

Seeps, springs, or other indications of subsurface water were not noted on the subject property during the time of our field investigation. The regional groundwater table is likely at elevations near mean sea level or approximately 350 feet below the lowest site elevation.

However, perched water seepage may occur locally (as a result of heavy precipitation and/or irrigation, or damaged wet underground utilities) along zones of contrasting permeabilities/densities (fill/bedrock contacts,sandy/clayey fill lifts, etc.) or along geologic discontinuities (contacts, joints/fractures). This potential should be anticipated and disclosed to all interested/affected parties.

Due to the potential for post-development perched water to manifest near the surface, owing to as-graded permeability/density contrasts, more onerous slab design is necessary for any new slab-on-grade floor(State of California,2021). Recommendations for reducing the amount of water and/or water vapor through slab-on-grade floors are provided in the "Soil Moisture Considerations" sections of this report.

FAULTING AND REGIONAL SEISMICITY
Regional Faults
Our review indicates that there are no known active faults crossing the project and the site is not within an Alquist-Priolo Earthquake Fault Zone (California Geological Survey [CGS], 2018). However,the site is situated in an area of active faulting. The Rose Canyon fault is the closest known active fault to the site (located at a distance of approximately 9.9 miles [16.0 kilometers]) and should have the greatest effect on the site Mr. Zoran Djordjevich W.O. 8058-A-SC
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in the form of strong ground shaking, should the design earthquake occur. The location of the Rose Canyon fault and other major faults relative to the site are shown on the "California Fault Map" in Appendix C. The possibility of ground acceleration, or shaking at the site, may be considered as approximately similar to the southern California region as a whole.

Local Faulting
Although active faults lie within a few miles of the site, no local active faulting was noted in our review, nor observed to specifically transect the site during the field investigation.

Additionally, a review of available regional geologic maps does not indicate the presence of local active faults crossing the specific project site.

Seismicity
The acceleration-attenuation relation of Bozorgnia, Campbell, and Niazi (1999) has been incorporated into EQFAULT (Blake, 2000a). EQFAULT is a computer program developed by Thomas F. Blake (2000a), which performs deterministic seismic hazard analyses using digitized California faults as earthquake sources. The program estimates the closest distance between each fault and a given site. If a fault is found to be within a user-selected radius, the program estimates peak horizontal ground acceleration that may occur at the site from an upper bound (formerly "maximum credible earthquake"), on that fault. Upper bound refers to the maximum expected ground acceleration produced from a given fault.

Site acceleration (g)was computed by one user-selected acceleration-attenuation relation that is contained in EQFAULT. Based on the EQFAULT program,a peak horizontal ground acceleration from an upper bound event on the Rose Canyon fault may be on the order of 0.407 g (1-sigma). The computer printouts of pertinent portions of the EQFAULT program are included within Appendix C.

Historical site seismicity was evaluated with the acceleration-attenuation relation of Bozorgnia, Campbell, and Niazi (1999), and the computer program EQSEARCH (Blake, 2000b, updated to August 2018). This program performs a search of the historical earthquake records for magnitude 5.0 to 9.0 seismic events within a 100-kilometer radius, between the years 1800 through August 2018. Based on the selected acceleration-attenuation relationship, a peak horizontal ground acceleration is estimated, which may have affected the site during the specific event listed. Based on the available data and the attenuation relationship used, the estimated maximum (peak) site acceleration during the period 1800 through August 2018 was about 0.209 g. A historic earthquake epicenter map and a seismic recurrence curve are also estimated/generated from the historical data. Computer printouts of the EQSEARCH program are presented in Appendix C.

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Seismic Shaking Parameters
It is our understanding that site-specific seismic design criteria from the 2019 California Building Code ([2019 CBC], California Building Standards Commission [CBSC], 2019a), are to be utilized for foundation design. Much of the 2019 CBC relies on the American Society of Civil Engineers (ASCE) Minimum Design Loads for Buildings and Other Structures (ASCE Standard 7-16). Based on the site conditions, the following table summarizes the updated site-specific design criteria obtained from the 2019 CBC, Chapter 16 Structural Design, Section 1613, Earthquake Loads. The computer program "OSHPD Seismic design Maps," provided by a joint effort between the Structural Engineers Association of California and the Office of Statewide Health Planning and Development ([OSHPD] SEAC/OSHPD,2021)was utilized for design ( http://seismicmaps.org) . The short spectral response utilizes a period of 0.2 seconds.
2019 CBC SEISMIC DESIGN PARAMETERS
PARAMETER VALUE 2019 CBC or REFERENCE
Risk Category II Table 1604.5
Site Class C Section 1613.2.2/Chap.20 ASCE 7-16 (p.203-204)
Spectral Response Section 1613.2.1(0.2 sec), SS 0.919 g Figure 1613.2.1(1) Spectral Response- (1 sec), S, 0.339 g Section 1613.2.1 Figure 1613.2.1(2)
Site Coefficient, Fa Table 1613.2.3(1)
Site Coefficient, Fv Table 1613.2.3(2)
Maximum Considered Earthquake Spectral 1.102 g Section 1613.2.3 Response Acceleration (0.2 sec), SMs (Eqn 16-36) Maximum Considered Earthquake Spectral 0.509 g Section 1613.2.3 Response Acceleration (1 sec), SM, (Eqn 16-37) 5% Damped Design Spectral Response 0.735 g Section 1613.2.4 Acceleration (0.2 sec), Sps (Eqn 16-38)
5% Damped Design Spectral Response Section 1613.2.4 Acceleration (1 sec), Sp, 0.477 g (Eqn 16-39) PGAM -Probabilistic Vertical Ground
Acceleration may be assumed as about 50%of 0. g ASCE 7-16 (Eqn 11.8.1) these values.

Seismic Design Category D Section 1613.2.5/ASCE 7-16 85: Table 11.6-1 or 11.6 2
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GENERAL SEISMIC PARAMETERS
PARAMETER VALUE
Distance to Seismic Source-Rose Canyon fault 9.9 mi(16.0 km)(" Upper Bound Earthquake-Rose Canyon fault MW = 7.2(" From Blake(2000a)
' Cao,et al. (2003)
Conformance to the criteria above for seismic design does not constitute any kind of guarantee or assurance that significant structural damage or ground failure will not occur in the event of a large earthquake. The primary goal of seismic design is to protect life, not to eliminate all damage, since such design may be economically prohibitive. Cumulative effects of seismic events are not addressed in the 2019 CBC and regular maintenance and repair following locally significant seismic events (i.e., MW5.5) will likely be necessary, as is the case in all of Southern California.

GEOLOGIC HAZARDS EVALUATION
Mass Wasting/Landslide Susceptibility
Mass wasting refers to the various processes by which earth materials are moved down slope in response to the force of gravity. Examples of these processes include slope creep, surficial failures, and deep-seated landslides. Creep is the slowest form of mass wasting and generally involves the outer 5 to 10 feet of a slope surface. During heavy rains, such as those in El Nino years, creep-affected materials may become saturated, resulting in a more rapid form of downslope movement (i.e., landslides and/or surficial failures).

According to regional landslide susceptibility mapping by Tan and Giffen (1995), the site is located within landslide susceptibility Subarea 3-1, which is characterized as being "generally susceptible"to landsliding. However,geomorphic expressions indicative of past mass wasting events (i.e., scarps, hummocky terrain, arcuate drainage courses, etc.)were not observed on the property during our field studies nor our review of stereoscopic aerial photographs. Further, no adverse geologic structures were encountered during our subsurface exploration. Regional geologic maps do not indicate the presence of landslide deposits on the property (Tan and Kennedy, 2007).

The onsite soils are considered erosive. Therefore, slopes comprised of these materials may be subject to rilling, gullying, sloughing, and surficial slope failures depending on rainfall severity and frequency, and surface drainage practices. Such risks can be minimized through properly designed, and regularly and periodically maintained surface drainage.

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SECONDARY SEISMIC HAZARDS
The following list includes other geologic/seismic related hazards that have been considered during our evaluation of the site. The hazards listed are considered negligible and/or mitigated as a result of site location, soil characteristics, and typical site development procedures:
• Liquefaction
• Lateral Spreading
• Subsidence
• Ground Lurching or Shallow Ground Rupture
• Tsunami
• Seiche
• Slope Stability

LABORATORY TESTING
Laboratory tests were performed on representative samples of site earth materials collected during our subsurface exploration in order to evaluate their physical characteristics. Test procedures used and results obtained are presented below.

Classification
Soils were visually classified with respect to the Unified Soil Classification System (U.S.C.S.) in general accordance with ASTM D 2487 and D 2488. The soil classifications of the onsite soils are provided on the Boring Logs in Appendix B.

Moisture-Density Relations
The field moisture contents and dry unit weights were determined for selected samples in the laboratory. Testing was performed in general accordance with ASTM D 2937 and ASTM D 2216. The dry unit weight was determined in pounds per cubic foot (pcf), and the field moisture content was determined as a percentage of the dry weight. The results of these tests are shown on the Boring Logs in Appendix B.

Expansion Index
A representative sample of near-surface site soil was evaluated for expansion potential.

Expansion Index (E.I.) testing and expansion potential classification was performed in general accordance with ASTM Standard D 4829, the results of the expansion testing are presented in the following table.

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SAMPLE LOCATION EXPANSION INDEX EXPANSION POTENTIAL

AND DEPTH (FT)
B-3 @ 11/2'-6' 18 Very Low
Atterberg Limits
Testing of a representative soil sample to evaluate its liquid limit, plastic limit, and plasticity index (P.I.) was performed in general accordance with ASTM D 4318. The test results are presented in Appendix D, and the following table:

SAMPLE LOCATION LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX B-2 @ 0'-4' 45 I 13 32
Laboratory Standard
The maximum density and optimum moisture content was evaluated for representative soil types in general accordance with the laboratory standard, ASTM D 1557. The moisture-density relationships obtained for this soil is shown in the following table:

SAMPLE DESCRIPTION MAXIMUM OPTIMUM MOISTURE LOCATION DENSITY (PCF) CONTENT (%)
13-2/13-3 @ 0'-6' Dark Brown, Clayey Sand 123.8 10.4 Direct Shear Test
Shear testing was performed on a representative, undisturbed sample of site soil in general accordance with ASTM Test Method D 3080 in a Direct Shear Machine of the strain control type. Prior to testing, the sample was remolded to 90 percent of the laboratory maximum density and its optimum moisture content (per ASTM D 1557). The shear test results are presented in Appendix D, and the following table:

PRIMARY RESIDUAL

SAMPLE LOCATION

AND DEPTH (FT) COHESION FRICTION ANGLE COHESION FRICTION ANGLE (PSF) (DEGREES) (PSF) I (DEGREES)
B-2/13-3 @ 0'-6' 274 28.5 155 28.8
(Remolded)
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Saturated Resistivity, pH, and Soluble Sulfates, and Chlorides GSI conducted sampling and testing of a representative sample of the onsite earth materials for general soil corrosivity and soluble sulfates,and chlorides testing. The testing included evaluation of soil pH, soluble sulfates, chlorides, and saturated resistivity. Test results are presented in the following table:

SAMPLE LOCATION SATURATED SOLUBLE SOLUBLE
AND DEPTH (FT) pH RESISTIVITY SULFATES CHLORIDES (ohm-cm) (% by weight) (PPm)
13-2/13-3 @ 0'-6' 6.8 1,600 0.005 40 Corrosion Summary
Laboratory testing indicates that the tested sample of the onsite soils is neutral with respect to soil acidity/alkalinity; is corrosive to exposed, buried metals when in a moist state; presents negligible sulfate exposure to concrete (Exposure Class SO per Table 19.3.1.1 of American Concrete Institute [ACI] 318-14), and contains low concentrations of soluble chlorides. It should be noted that GSI does not consult in the field of corrosion engineering. Thus,the Client may obtain additional consultation from a qualified corrosion engineer based on the level of corrosion protection required for the project, as determined by the Client, the Project Architect, the Project Structural Engineer, and the Project Civil Engineer.

STORM WATER TREATMENT AND HYDROMODIFICATION MANAGEMENT
USDA Study
A review of the United States Department of Agriculture database ([USDA]; 1973, 2021) indicates that site soils are classified as Bosanko Clay (9 to 15 percent slopes [BsD]) and Placentia Sandy Loam (5 to 9 percent slopes [PeC2]). The USDA study further indicates that the onsite soils are classified as belonging to Hydrologic Soil Group "D," which generally warrants "no" infiltration conditions, based on infiltration rates alone.

Infiltration Feasibility
In general accordance with the City BMP design manual (City, 2016), the infiltration feasibility for this site was evaluated. An evaluation of the soils infiltration characteristics and potential impact on site development was performed for this evaluation, using a"desk top" analysis. A review of USDA (1973 and 2021) indicates that the capacity of the most Mr. Zoran Djordjevich W.O. 8058-A-SC
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limiting layer to transmit water (Ksat) within both the Bosanko Clay and Placentia Sandy Loam (BsD & PeC2), is very low to moderately low (0.00 to 0.06 inches per hour [in/hr]).

The USDA further indicates that these soils (BsD & PeC2) fall into Hydrologic Soil Group (HSG) "D", which may be assigned a design infiltration rate of 0.025 inches per hour (no correction/safety factors required), based on the Natural Resources Conservation Service (NRCS) soil type default design infiltration rates. This design infiltration rate is below the recommended feasibility threshold of 0.52 inches per hour per the EPA(Clar, et al., 2004), and 0.50 inches per hour per the City (2016) for full infiltration. In general,the permeability of the underlying soil/bedrock can be expected to decrease with depth,as the soil/bedrock becomes less weathered, thereby promoting the lateral migration of water in soil.

Storm water BMPs can adversely affect the performance of the onsite and offsite structures foundation systems by: 1) increasing soil moisture transmission rates through concrete flooring; 2) reducing the stability of slopes and; and 3) increasing the potential for a loss in bearing strength of soil. Infiltration would increase this potential, as well as the potential for distress to proposed onsite and existing offsite improvements. Further, any onsite mitigative grading of compressible near-surface soils forthe support of structures generally involves removal and recompaction. This is anticipated to create a permeability contrast, and exacerbate the potential for the development of a shallow "perched" and mounded water table, which can reasonably be anticipated to migrate laterally, beneath the structure(s),and offsite onto adjacent property,causing settlement and associated distress to public and private improvements.

Based on our review and engineering analysis, the site generally appears unsuitable for storm water infiltration from a geotechnical viewpoint. As such, a "no infiltration" BMP design is recommended. Furthermore, any basin constructed entirely of compacted fill is considered as belonging to Hydrologic Soil Group "D," and a "no infiltration" BMP design is warranted ([EPA], Clar, et al., 2004). For hydromodification structures located within 10 feet of a structure or settlement-sensitive improvement, storm water treatment and hydromodification management should be designed for no infiltration. The civil designer should also take into account that any infiltrated storm water would likely perch upon the underlying bedrock and migrate laterally, potentially adversely impacting improvements on adjoining properties, including utility slopes and trenches. An additional discussion of infiltration feasibility is presented in Appendix E, which contains a categorization of infiltration feasibility worksheet, Worksheet C.4-1, and a Factor of safety infiltration rate worksheet, Worksheet D.5-1 , provided by the City (2016).

Onsite Infiltration-Runoff Retention Systems
General design criteria regarding the use of onsite infiltration-runoff retention systems (OIRRS) are presented below. Should onsite infiltration-runoff retention systems (OIRRS) be planned for Best Management Practices (BMPs) or Low Impact Development (LID) principles for the project, some guidelines should be followed in the planning, design, and Mr. Zoran Djordjevich W.O. 8058-A-SC
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construction of such systems. Such facilities, if improperly designed or implemented without consideration of the geotechnical aspects of site conditions, can contribute to flooding, saturation of bearing materials beneath site improvements, slope instability, and possible concentration and contribution of pollutants into the groundwater or storm drain and/or utility trench systems.

A key factor in these systems is the infiltration rate (sometimes referred to as the percolation rate) which can be ascribed to, or determined for, the earth materials within which these systems are installed. Additionally,the infiltration rate of the designed system (which may include gravel, sand, mulch/topsoil, or other amendments, etc.) will need to be considered. The project infiltration testing is very site specific, any changes to the location of the proposed OIRRS and/or estimated size of the OIRRS, may require additional infiltration testing. Locally, relatively impermeable residual soils include the underlying bedrock, which is anticipated to have a very low vertical infiltration rate.

The following geotechnical guidelines should be considered when designing onsite infiltration-runoff retention systems:
• The onsite soils fall into Hydrologic Soil Group (HSG) "D." As such, a design infiltration rate of 0.025 inches/hour is assigned per NRCS soil type default design infiltration rates, should it be required.
• It is not good engineering practice to allow water to saturate soils, especially near slopes or improvements; however, the controlling agency/authority may now require this.
• Areas adjacent to, or within, the OIRRS that are subject to inundation should be properly protected against scouring, undermining, and erosion, in accordance with the recommendations of the design engineer.
• Should they be required, where infiltration systems are located near slopes or improvements, impermeable liners and subdrains should be used along the bottom of bioretention swales/basins located within the influence of such slopes and structures. Impermeable liners used in conjunction with bioretention basins should consist of a 30-mil polyvinyl chloride (PVC) membrane that is covered by a minimum of 12 inches of clean soil, free from rocks and debris, with a maximum 4:1 (h:v) slope inclination, or flatter, and meets the following minimum specifications:

Specific Gravity (ASTM D792): 1.2 (g/cc, min.); Tensile (ASTM D882):
73 (lb/in-width, min); Elongation at Break (ASTM D882): 380 (%, min); Modulus (ASTM D882): 32 (lb/in-width, min.); and Tear Strength (ASTM D1004): 8 (lb/in, min); Seam Shear Strength (ASTM D882)

58.4 (lb/in, min); Seam Peel Strength (ASTM D882) 15 (lb/in, min).

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• Subdrains for basins should consist of at least 4-inch diameter Schedule 40 or SDR 35 drain pipe with perforations oriented down. The drain pipe should be sleeved with a filter sock.
• Utility backfill within OIRRS should consist of a two-sack mix of slurry.

Final project plans (grading, precise grading,foundation, retaining wall, landscaping, etc.), should be reviewed by this office prior to construction, so that construction is in accordance with the conclusions and recommendations of this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted. It should be noted that structural and landscape plans were not available for review at this time.

PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS
Based on our field exploration, laboratory testing, and geotechnical engineering analysis, it is our opinion that the subject site is suitable for the proposed residential development from a geotechnical engineering and geologic viewpoint, provided that the recommendations presented in thefollowing sections are incorporated into the design and construction phases of site development. The primary geotechnical concerns with respect to the proposed development and improvements are:
• Earth material characteristics and depth to competent bearing material below the existing grades.
• Perimeter conditions and planned improvements near the property boundary. • On-going expansion and corrosion potentials of the onsite soils. • Temporary slope stability.
• Erosiveness of site earth materials.
• Potential for perched water during and following site development. • Regional seismic activity.

The recommendations presented herein consider these as well as other aspects of the site.

The engineering analyses performed concerning site preparation and the recommendations presented herein have been completed using the information provided and obtained during our field work.

In the event that any significant changes are made to proposed site development, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the recommendations of this report verified or modified in writing by this office. Foundation design parameters are considered preliminary until the foundation design, layout, and structural loads are provided to this office for review.

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1. Soil engineering, observation, and testing services should be provided during grading to aid the contractor in removing unsuitable soils and in his effort to compact the fill.

2. Geologic observations should be performed during any grading and foundation construction to verify and/orfurther evaluate geologic conditions. Although unlikely, if adverse geologic structures are encountered, supplemental recommendations and earthwork may be warranted.

3. All undocumented artificial fill,colluvium, and highly weathered granitic bedrock are considered unsuitable for the support of the planned settlement-sensitive improvements (i.e., the residential structure, walls, underground utilities, the driveway pavement, hardscape, etc.) and new planned fills. Unsuitable soils within the influence of planned settlement-sensitive improvements and planned fill should be removed to expose suitable granitic bedrock and then be reused as properly engineered fill. Based on the available subsurface data, remedial grading excavations are anticipated to extend to a depth of approximately 2 to 4 feet below the existing grades. However,variations should be anticipated and deeper remedial grading excavations cannot be precluded.

4. Current laboratory testing indicates that some of the onsite sandy soils exhibit expansion index values less than 21. However, the onsite clayey soils exhibit a plasticity Index (PI) of PI=32. As such, some of the site soils appear to meet the criteria for detrimentally expansive soils as defined in Section 1803.5.3 of the 2019 CBC (CBSC, 2019a).

Residential building foundations within the influence of expansive soils should be designed and constructed in accordance with Sections 1808.6.1 or 1808.6.2 of the 2019 CBC. If post-grading soils are detrimentally expansive, foundation systems used for the mitigation of expansive soils typically incorporate the Post-Tension Institute (PTI) or Wire Reinforcement Institute (WRI) methodologies.

5. Laboratory testing indicates that a representative sample of the onsite soils is neutral with respect to soil acidity/alkalinity and is corrosive to exposed buried metals when in a moist state. Testing also indicates that the sample presents negligible sulfate exposure to concrete (Exposure Class SO per Table

19.3.1 .1 of American Concrete Institute [ACI] 318-14) and contains low concentrations of soluble chlorides. It should be noted that GSI does not consult in the field of corrosion engineering. Thus, the Client may obtain additional consultation from a qualified corrosion engineer based on the level of corrosion protection required for the project, as determined by the Client, the Project Architect, and the Project Structural Engineer.

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6. Site soils are considered erosive. Surface drainage should be designed to eliminate the potential for concentrated surface flows. Positive surface drainage away from foundations and tops of slopes is recommended. Temporary erosion control measures should be implemented until vegetative covering is well established. The property owner will need to maintain proper surface drainage over the life of the development. This should be disclosed to all interested/affected parties.

7. No evidence of a high regional groundwater table nor perched water was observed during our subsurface exploration within the property. However, due to the nature of site earth materials, there is a potential for perched water to occur both during and following site development. This potential should be disclosed to all interested/affected parties. Should perched water conditions be encountered, this office could provide recommendations for mitigation. Typical mitigation includes subdrainage system, cut-off barriers, etc.

8. The removal and recompaction of potentially compressible soils below a 1 :1 (h:v) plane projected down from the bottom, outside edge of planned settlement- sensitive improvements and fill along the perimeter of the site will likely be limited due to boundary restrictions. As such, any settlement-sensitive improvement located above a 1 :1 (h:v) plane projected up from the bottom outboard edge of the remedial grading excavation at the property line would require deepened foundations below this plane, additional reinforcement, or would retain some potential for distress and therefore, a reduced service life. On a preliminary basis, any planned settlement-sensitive improvements located within a few feet from the subdivision boundary would require deepened foundations or additional reinforcement by means of ground improvement or specific structural design. This should be disclosed to all interested/affected parties.

9. On a preliminary basis,temporary slopes should be constructed in accordance with CAL-OSHA guidelines for Type "B" soils, provided water or seepage is not present.

All temporary slopes should be evaluated by the geotechnical consultant, prior to worker entry. Should adverse conditions be identified, the slope may need to be laid back to a flatter gradient or require the use of shoring.

10. The seismicity-acceleration values provided herein should be considered during the design and construction of the proposed development.

11. General Earthwork and Grading Guidelines are provided at the end of this report as Appendix F. Specific recommendations are provided below.

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EARTHWORK CONSTRUCTION RECOMMENDATIONS
General
All earthwork should conform to the guidelines presented in the 2019 CBC (CBSC, 2019), the requirements of the City of Vista, and the General Earthwork and Grading Guidelines presented in Appendix F, except where specifically superceded in the text of this report.

Prior to earthwork, a GSI representative should be present at the preconstruction meeting to provide additional earthwork guidelines, if needed, and review the earthwork schedule.

This office should be notified in advance of any fill placement, supplemental regrading of the site, or backfilling underground utility trenches and retaining walls after rough earthwork has been completed. This includes grading for driveway approaches, driveways, and exterior hardscape.

During earthwork construction, all site preparation and the general grading procedures of the contractor should be observed and the fill selectively tested by a representative(s) of GSI. If unusual or unexpected conditions are exposed in the field,they should be reviewed by this office and, if warranted, modified and/or additional recommendations will be offered. All applicable requirements of local and national construction and general industry safety orders,the Occupational Safety and Health Act(OSHA),and the Construction Safety Act should be met. It is the onsite general contractor and individual subcontractors responsibility to provide a safe working environment for our field staff who are onsite. GSI does not consult in the area of safety engineering.

Site Preparation
All existing improvements, vegetation and deleterious debris should be removed from the site prior to the start of construction if they are located in areas of proposed earthwork.

Any remaining cavities should be observed by the geotechnical consultant. Mitigation of cavities would likely include removing any potentially compressible soils to expose suitable bedrock and then backfilling the excavation with a controlled engineered fill or soils that have been moisture conditioned to optimum moisture content and compacted to at least 90 percent of the laboratory standard (ASTM D 1557).

Removal and Recompaction of Potentially Compressible Earth Materials Potentially compressible undocumented fill, colluvium, and highly weathered granitic bedrock should be removed to expose suitable granitic bedrock. Following removal,these soils should be cleaned of any vegetation and deleterious debris, moisture conditioned to at least optimum moisture, and then be recompacted to at least 90 percent of the laboratory standard (per ASTM D 1557). Based on the available data, excavations necessary to remove unsuitable soils are anticipated to range up to approximately 2 to 4 feet across the site. The potential to encounter thicker sections of Mr. Zoran Djordjevich W.O. 8058-A-SC
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unsuitable soils that require deeper remedial grading excavations than stated above cannot be precluded and should be anticipated. Potentially compressible soils should be removed below a 1 :1 (h:v) projection down from the bottom, outboard edge of any settlement-sensitive improvement or limits of planned fill. Remedial grading excavations should be observed bythe geotechnical consultant priorto scarification and fill placement.

Once observed and approved, the bottom of the remedial grading excavation should be scarified at least 6 to 8 inches, moisture conditioned to at least the soil's optimum moisture content, and then recompacted to a minimum 90 percent of the laboratory standard (ASTM D 1557). Based on the distribution of soils, including highly weathered bedrock, blending/mixing of any minor amounts of expansive soil should be performed during grading to reduce the overall expansive character of site soil.

Owing to the age of the existing development at the site, it is possible that underground structures (i.e., utilities, cisterns, seepage pits, etc.) may be encountered during remedial grading. This office should be informed if any underground structures are encountered during remedial earthwork. Based on the exposed conditions, this office would provide recommendations for earthwork mitigation.

Perimeter Conditions
General
It should be noted that the 2019 CBC (CBSC, 2019) indicates that the removal of unsuitable soils be performed across all areas to be graded, under the purview of the grading permit, not just within the influence of the residential structure. Relatively deep removals may also necessitate a special zone of consideration, on perimeter/confining areas. This zone would be approximately equal to the depth of removals, if removals cannot be performed onsite or offsite. In general, any planned improvement located above a 1 :1 (h:v) projection up from the bottom, outboard edge of the remedial grading excavation at the site boundary would be affected by perimeter conditions. On a preliminary basis, any planned settlement-sensitive improvements located within about 2-4 feet of the site boundary would require deepened foundations, underpinning, or additional reinforcement by means of ground improvement or specific structural design, for perimeter conditions discussed above. Otherwise,these improvements may be subject to distress and a reduced service life, or even adversely affect offsite buildings/improvements. This will also require proper disclosure to all interested/affected parties should this condition exist at the conclusion of grading. The need for remedial measures for support of settlement-sensitive improvements near the site boundary should be further evaluated at the grading plan review stage.

Overexcavation
In order to provide uniform foundation and slab-on-grade floor support, mitigate water vapor transmission potential, and to facilitate trenching for foundations and Mr. Zoran Djordjevich W.O. 8058-A-SC
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underground utilities, it is recommended that the building pads be overexcavated (undercut) to a depth of at least 3 feet below pad grade, or 2 feet below the lowest bottom of the footing elevation (whichever is greater). When removals do not provide for the minimum fill thickness with a given building pad, the building pad shall be overexcavated as described above.

Overexcavation should be completed for a horizontal distance of at least 5 feet outside the perimeter foundation elements, including any exterior column footings. If there is a potential forthe building layout or location to change,following site grading,the horizontal limits of overexcavation should be enlarged a sufficient distance to capture and extend a few feet beyond the perimeter foundation elements. Otherwise, additional remedial grading or other mitigation could be required during building foundation construction. The maximum to minimum fill thickness across the building pad should not exceed 3:1 (maximum:minimum). Prior to fill placement,the bottom of the overexcavation should observed by GSI, and then be scarified at least 6 to 8 inches, moisture conditioned to at least the soil's optimum moisture content, and then recompacted to a minimum 90 percent of the laboratory standard (ASTM D 1557).

Alternating Slot Excavations
Alternating "A", "B", and "C" slot excavations should be performed when completing remedial earthwork below a 1 :1 (h:v) plane projected down from property lines, existing improvements, and/or the top-of-pipe elevation at a point located <5 horizontal feet from the center of existing, active underground utilities. The width of an open slot should be no greater than 6 feet. Multiple slots may be excavated simultaneously provided that open slots are separated by a 12-foot width of undisturbed soils or recompacted fill. Open slots should be observed by GSI prior to backfill.

Eastern Property Line
PLSA (2020) indicates a proposed private road to be located along the eastern property line,where an existing free-standing CMU wall occurs on the property line, and other minor improvements near the property line. Assuming the potential for relatively deep removals to occur within the eastern portion of the site, onsite excavations could potentially undermine the existing wall foundation system, thus increasing the potential for distress to existing offsite improvements. Mitigation of this potential distress would include, but not necessarily be limited to: construction in alternating sections/slots, and/or underpining/shoring the existing offsite structure.

Fill Placement
Following scarification of the bottom of the remedial grading excavation, the reused onsite soils and import (if necessary) should be placed in ±6- to ±8-inch lifts, cleaned of vegetation and debris, moisture conditioned to at least optimum moisture content, and Mr. Zoran Djordjevich W.O. 8058-A-SC
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compacted to achieve a minimum relative compaction of 90 percent of the laboratory standard (ASTM D 1557). Underground utility trench and retaining wall backfills should conform to similar placement standards. Any rock constituents greater than 12 inches in dimension should not be incorporated into fills placed within the building pads or within the footprints of retaining wall foundations. Rock constituents greater than 3 inches in dimension should not be incorporated into underground utility trench or retaining wall backfill materials. Underground utility providers may have stricter requirements for the placement of rock materials within their utility trenches.

Import Soils
If import fill is necessary, a sample of the soil import should be evaluated by this office prior to importing, in order to assure compatibility with the onsite soils and the recommendations presented in this report. If non-manufactured materials are used, environmental documentation for the export site should be provided for GSI review. At least three business days of lead time should be allowed by builders or contractors for proposed import submittals. This lead time will allow for environmental document review, particle-size analysis, laboratory standard, expansion testing, and blended import/native characteristics as deemed necessary. Import soils should be very low expansive (i.e., E.I. < 20 with a P.I. < 14). The use of subdrains at the bottom of the fill cap may be necessary, and may be subsequently recommended based on compatibility with onsite soils.

Graded Slopes
Significant graded slopes are not planned, nor anticipated for this project.

Temporary Slopes
Temporary slopes for excavations greater than 4 feet, but less than 20 feet in overall height should conform to CAL-OSHA and/or OSHA requirements for Type "B" soils, provided running sands, water, or seepage are not present. Temporary slopes, up to a maximum height of ±20 feet, may be excavated at a 1 :1 (h:v) gradient, or flatter, provided groundwater and/or running sands are not exposed. Equipment traffic/storage or construction material, or soil stockpiles should not be within `H' of any temporary slope where `H' equals the height of the temporary slope. All temporary slopes should be observed by a licensed engineering geologist and/or geotechnical engineer prior to worker entry into the excavation. Based on the exposed field conditions, inclining temporary slopes to flatter gradients or the use of shoring may be necessary if adverse conditions are observed. If temporary slopes conflict with property boundaries, shoring or alternating slot excavations may be necessary. The need for shoring or alternating slot excavations could be further evaluated during the grading plan review stage.

Earthwork Balance (Shrinkage/Bulking)
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The volume change of excavated materials upon compaction as engineered fill is anticipated to vary with material type and location. Based on the available data,the overall earthwork shrinkage and bulking may be approximated by using the following parameters:

Undocumented Artificial Fill/Quaternary Colluvium . . . . . . 5% to 10% shrinkage Bedrock
75% Earth/25% Rock (weathered bedrock) . . . . . . . . . . . . . . 8% shrinkage 50% Earth/50% Rock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5% shrinkage 25% Earth/75% Rock (unweathered bedrock) . . . . . . . . . . . . . 12% bulking It should be noted that the above factors are estimates only, based on preliminary data.

Existing weathered bedrock may achieve higher shrinkage if organics or clay content is higher than anticipated, or if compaction averages more than 92 percent of the laboratory standard (ASTM D 1557). Final earthwork balance factors could vary. In this regard, grades could be adjusted up or down near the completion of grading in order to accommodate any yardage imbalance for the project.

PRELIMINARY RECOMMENDATIONS - FOUNDATIONS
General
Preliminary recommendations for foundation design and construction are provided in the following sections. These preliminary recommendations have been developed from our understanding of the currently planned site development, site observations, subsurface exploration, laboratory testing, and engineering analyses. Foundation design should be re-evaluated at the conclusion of site grading/remedial earthwork for the as-graded soil conditions. Although not anticipated, revisions to these recommendations may be necessary. In the event that the information concerning the proposed development plan is not correct, or any changes in the design, location or loading conditions of the proposed additions are made, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and conclusions of this report are modified or approved in writing by this office.

The information and recommendations presented in this section are not meant to supercede design by the project structural engineer or civil engineer specializing in structural design. Upon request, GSI could provide additional input/consultation regarding soil parameters, as related to foundation design.

Expansive/Corrosive Soils
Tests performed on representative soil samples (in general accordance with ASTM D 4829) to evaluate soil expansion indicate very low (expansion index [E.I.] less than 21 evaluated) expansive soil conditions for silty sand material, with a plasticity index (P.I.) evaluated as Mr. Zoran Djordjevich W.O. 8058-A-SC
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P.I. = 32 for the higher expansive soils onsite. As such, some of the site soils meet the criteria of expansive soils as defined in Section 1803.5.2 of the 2019 CBC. Foundation systems constructed within the influence of detrimentally expansive soils(i.e., E.I. > 20 and P.I. > 15) will require specific design to resist expansive soil effects per Sections 1808.6.1 or 1808.6.2 of the 2019 CBC, and should be provided by the project structural engineer.

Reinforced concrete mix design for foundations, slab-on-grade floors, and pavements should conform to "Exposure Classes SO, W0, and C1" in Table 19.3.2.1 of ACI 31813-14, as concrete would likely be exposed to moisture.

Preliminary Foundation Design
The following foundation construction recommendations are presented as a minimum criteria from a soils engineering viewpoint. Site soils are expansive, as such, foundations will also require specific design by the structural engineer to mitigate expansive soil effects as required in Sections 1808.6.1 or 1808.6.2 of the 2019 CBC.

1. The foundation systems should be designed and constructed in accordance with guidelines presented in the 2019 CBC.

2. An allowable bearing value of 2,000 pounds per square foot (psf) may be used for the design of footings that maintain a minimum width of 12 inches and a minimum depth of 18 inches (below the lowest adjacent grade) and are founded entirely into properly compacted, engineered fill, or suitable fill. This value may be increased by 20 percent for each additional 12 inches in footing depth to a maximum value of 2,500 psf. These values may be increased by one-third when considering short duration seismic or wind loads. Isolated pad footings should have a minimum dimension of at least 24 inches square and a minimum embedment of 24 inches below the lowest adjacent grade into properly engineered fill. Foundation embedment depth excludes concrete slabs-on-grade, and/or slab underlayment.

Foundations should not simultaneously bear on bedrock and engineered fill.

3. For foundations deriving passive resistance from engineered fill, a passive earth pressure may be computed as an equivalent fluid having a density of 250 pcf, with a maximum earth pressure of 2,500 psf.

4. The upper 6 inches of passive pressure should be neglected if not confined by slabs or pavement.

5. For lateral sliding resistance, a coefficient of friction of 0.35 pcf may be utilized for a concrete to soil contact, when multiplied by the dead load. When combining passive pressure and frictional resistance,the passive pressure component should be reduced by one-third.

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6. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third.

7. All footing setbacks from slopes should comply with Figure 1808.7.1 of the 2019 CBC. GSI recommends a minimum horizontal setback distance of 7 feet as measured from the bottom, outboard edge of the footing to the slope face.

8. Footings for structures adjacent to retaining walls should be deepened so as to extend below a 1 :1 projection from the heel of the wall. Alternatively, walls may be designed to accommodate structural loads from buildings or appurtenances as described in the "Retaining Wall" section of this report.

9. Provided that the earthwork and foundation recommendations in this reported are adhered foundations bearing on engineered fill should be minimally designed to accommodate a differential settlement of 1 inch over a 40-foot horizontal span (angular distortion = 1/480).

PRELIMINARY FOUNDATION CONSTRUCTION RECOMMENDATIONS
Current laboratory testing indicates that some onsite soils meet the criteria of detrimentally expansive soils as defined in Section 1803.5.3 of the 2019 CBC. The following foundation construction recommendations are presented as a minimum criteria from a soils engineering viewpoint. However, as some site soils are expansive, foundations may also require specific design by the structural engineer to mitigate expansive soil effects as required in Sections 1808.6.1 or 1808.6.2 of the 2019 CBC.

The following foundation construction recommendations are presented as a minimum criteria from a soils engineering viewpoint. The following foundation construction recommendations are intended to support planned improvements underlain by at least 4 feet of non-detrimentally expansive soils (i.e., E.I.<21 and P.I. <15). Should foundations be underlain by expansive soils with expansion indices exceeding 21 at depths of less than 7 feet,they will require specific design to mitigate expansive soil effects as required in Sections 1808.6.1 or 1808.6.2 of the 2019 CBC (CBSC, 2019).

1. Exterior and interior footings should be founded into engineered fill at a minimum depths of 12 inches (very low expansive soil), or 18 inches (low to medium expansive soil, or 24 inches for high expansive soils), below the lowest adjacent grade, and a minimum width of 12 or 15 inches, for the planned, one- or two-story floor load structure, respectively. Isolated, exterior column and panel pads, or wall footings, should be at least 24 inches, square, and founded at a minimum depth of 24 inches into properly engineered fill. All footings should be minimally reinforced with four No. 4 reinforcing bars, two placed near the top and two placed near the bottom of the footing. Reinforcement of pad footing should be provided by the projects structural engineer.

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2. All interior and exterior column footings, and perimeter wall footings, should be tied together via grade beams in two directions. The grade beam should be at least 12 inches square in cross section, and should be provided with a minimum of one No. 4 reinforcing bar at the top, and one No. 4 reinforcing bar at the bottom of the grade beam. The base of the reinforced grade beam should be at the same elevation as the adjoining footings.

3. A grade beam, reinforced as previously recommended and at least 12 inches square, should be provided across large (garage) entrances. The base of the reinforced grade beam should be at the same elevation as the adjoining footings.

4. A minimum concrete slab-on-grade thickness of 5 inches is recommended.

Recommendations for floor slab underlayment are presented in a later section of this report.

5. Concrete slabs should be reinforced with a minimum of No. 3 reinforcement bars placed at 18-inch on centers, in two horizontally perpendicular directions (i.e., long axis and short axis).

6. All slab reinforcement should be supported to ensure proper mid-slab height positioning during placement of the concrete. "Hooking" of reinforcement is not an acceptable method of positioning.

7. Specific slab subgrade pre-soaking is recommended for these soil conditions. Prior to the placement of underlayment sand and vapor retarder, GSI recommends that the slab subgrade materials be moisture conditioned to at least optimum moisture content to a minimum depth of 12 inches. Slab subgrade pre-soaking should be evaluated by the geotechnical consultant within 72 hours of the placement of the underlayment sand and vapor retarder.

8. Soils generated from footing excavations to be used onsite should be compacted to a minimum relative compaction of 90 percent of the laboratory standard (ASTM D 1557), whether the soils are to be placed inside the foundation perimeter or in the yard/right-of-way areas. This material must not alter positive drainage patterns that direct drainage away from the structural areas and toward the street.

9. Reinforced concrete mix design should conform to "Exposure Class SO and C1" in Table 19.3.2.1 of ACI 318R-14.

Stiffened Slabs
All foundations supported by expansive soils (as defined per Section 1803.5.3 of the 2019 CBC), shall be in compliance with Section 1808.6 of the 2019 CBC (CBSC, 2019), and the findings of this report.

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For a typical slab designed with interior ribs, or stiffeners, the slab should minimally be at least 5 inches thick. The ribs should be provided in both transverse and longitudinal directions. The interior rib spacing and depth should be provided by the project structural engineer. The perimeter beams, however, should be embedded at least 18 inches for medium expansion, and in consideration of the building type. The embedment depth should be measured downward from the lowest adjacent grade surface to the bottom of the beam.

Structural Mat Foundations - Design/Construction
The design of mat foundations should incorporate the vertical modulus of subgrade reaction. This value is a unit value for a 1-foot square footing and should be reduced in accordance with the following equation when used with the design of larger foundations.

This assumes that the bearing soils will consist of engineered fills with an average relative compaction of 90 percent of the laboratory (ASTM D 1557), overlying dense formational earth materials.

B + 7 2
213
where: Ks = unit subgrade modulus
KR = reduced subgrade modulus
B = foundation width (in feet)
The modulus of subgrade reaction (Ks) and effective plasticity index (P.I.)to be used in mat foundation design for various expansive soil conditions are presented in the following table.

LOW EXPANSION MEDIUM EXPANSION
E.I. = 0-50 E.I. = 51-90
K =100 pci/inch, P.I. 30
Reinforcement bar sizing and spacing for mat slab foundations should be provided by the structural engineer. Mat slabs may be uniform thickness foundations (UTF) or may incorporate the use of edge footings for moisture cut-off barriers as recommended herein for post-tension foundations. Edge footings should be a minimum of 6 inches thick. The bottom of the edge footing should be designed to resist tension, using reinforcement per the structural engineer. The need and arrangement of interior grade beams (stiffening beams) will be in accordance with the structural consultant's recommendations. The recommendations for a mat type of foundation assume that the soils below the slab are compacted fill overlying dense, unweathered bedrock materials. The parameters herein are to mitigate the effects of expansive soils and should be modified to mitigate the effects Mr. Zoran Djordjevich W.O. 8058-A-SC
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of the total and differential settlements reported earlier in this report. GSI recommends that the slab subgrade materials be moisture conditioned per recommendations presented in the previous section on general foundation construction.

In order to mitigate the effects from post-development perched water and to impede water vapor transmission, structural mats, shall be in accordance with Table 19.3.2.1 of the ACI (2014) per the 2019 CBC. Recommendations for slab underlayment and soil moisture transmission considerations are presented in a later section of this report.

Nuisance cracking may be lessened by the addition of engineered reinforcing fibers in the concrete and careful control of water/cement ratios. For below grade structures (garages, etc.) epoxy-coated reinforcing bars should be considered and are dependent on the structural consultant's waterproofing and corrosion specialists' recommendations.

Post Tension Slab Foundation Design/Construction
Post-tension (PT) foundations should be used to mitigate the damaging effects of expansive soils on the planned residential foundations and slab-on-grade floors if expansive soil conditions are encountered within 7 feet of finish grade. They may also be used for increased performance of foundations constructed on non-detrimentally expansive soils.

The PT foundation designer may elect to exceed these minimal recommendations to increase slab stiffness performance. PT design may be either ribbed or mat-type. The latter is also referred to as uniform thickness foundation (UTF). The use of a UTF is an alternative to the traditional ribbed-type. The UTF offers a reduction in grade beams (i.e., that method typically uses a single perimeter grade beam and possible "shovel"footings), but has a thicker slab than the ribbed-type.

The information and recommendations presented in this section are not meant to supercede design by a registered structural engineer or civil engineer qualified to perform post-tensioned design. PT foundations should be designed using sound engineering practice and be in accordance with local and 2019 CBC requirements. Upon request, GSI can provide additional data/consultation regarding soil parameters as related to post-tensioned foundation design.

From a soil expansion/shrinkage standpoint, a common contributing factor to distress of structures using post-tensioned slabs is a"dishing"or"arching"of the slabs. This is caused by the fluctuation of moisture content in the soils below the perimeter of the slab primarily due to onsite and offsite irrigation practices, climatic and seasonal changes, and the presence of expansive soils. When the soil environment surrounding the exterior of the slab has a higher moisture content than the area beneath the slab, moisture tends to migrate inward, underneath the slab edges to a distance beyond the slab edges referred to as the moisture variation distance. When this migration of water occurs, the volume of the soils beneath the slab edges expand and cause the slab edges to lift in response. This Mr. Zoran Djordjevich W.O. 8058-A-SC
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is referred to as an edge-lift condition. Conversely, when the outside soil environment is drier,the moisture transfer regime is reversed and the soils underneath the slab edges lose their moisture and shrink. This process leads to dropping of the slab at the edges, which leads to what is commonly referred to as the center lift condition. A well-designed, PT slab having sufficient stiffness and rigidity provides a resistance to excessive bending that results from non-uniform swelling and shrinking slab subgrade soils, particularly within the moisture variation distance, near the slab edges. Other mitigation techniques typically used in conjunction with post-tensioned slabs consist of a combination of specific soil pre-saturation and the construction of a perimeter "cut-off" wall grade beam. Soil pre-saturation consists of moisture conditioning the slab subgrade soils prior to the PT slab construction. This effectively reduces soil moisture migration from the area located outside the building toward the soils underlying the post-tension slab. Perimeter cut-off walls are thickened edges of the concrete slab that impedes both outward and inward soil moisture migration.

Slab Subgrade Pre-Soaking
Pre-moistening of the slab subgrade soil is recommended for these soil conditions. The moisture content of the subgrade soils should be equal to or greater than optimum moisture to a depth equivalent to the exterior footing depth in the slab areas (typically 12, 18, and 24 inches for very low to low, medium, and highly expansive soils, respectively). Pre-moistening and/or pre-soaking should be evaluated by the soils engineer 72 hours prior to vapor retarder placement. In summary:

EXPANSION CONSTRUCTION SOIL MOISTURE
INDEX PAD SOIL MOISTURE METHOD RETENTION Periodically wet or cover with
Very Low (0-20) Upper 12 inches of pad at or plastic after trenching. (not anticipated) above soil optimum moisture Wetting and/or reprocessing Evaluation 72 hours prior to placement of concrete.

Upper 12 inches of pad soil Periodically wet or cover with Low (21-50) moisture 2 percent over Wetting and/or reprocessing plastic after trenching. optimum Evaluation 72 hours prior to
placement of concrete.

Upper 18 inches of pad soil Periodically wet or cover with moisture 2 percent over germ and flood or wetting plastic after trenching.

Medium (51-90) optimum or 1.2 times and reprocessing Evaluation 72 hours prior to optimum, whichever is placement of concrete. reater.

Perimeter Cut-Off Walls
Perimeter cut-off walls should be 12, 18, and 24 inches deep for very low to low, medium, and high to very highly expansive soil conditions, respectively. The cut-off walls may be Mr. Zoran Djordjevich W.O. 8058-A-SC
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integrated into the slab design or independent of the slab. The cut-off walls should be a minimum of 6 inches thick. The bottom of the perimeter cut-off wall should be designed to resist tension, using cable or reinforcement per the structural engineer.

Post-Tensioned Foundation Design
The following recommendations for design of post-tensioned slabs have been prepared in general compliance with the requirements of the PTI (2014, 2013, and 2012).

Soil Support Parameters
The recommendations for soil support parameters have been provided based on the typical soil index properties for soils that are very low to high in expansion potential. The soil index properties are typically the upper bound values based on our experience and practice in the southern California area. The following table presents suggested minimum coefficients to be used in the Post-Tensioning Institute design method.

Thornthwaite Moisture Index -20 inches/year
Correction Factor for Irrigation 20 inches/year
Depth to Constant Soil Suction 7 feet
Constant soil Suction (pf) 3.6
Moisture Velocity 0.7 inches/month
Plasticity Index P.I. <15-50
The following table presents foundation design parameters for post-tensioned slab foundations relative to a specific range of soil expansion potential in accordance with the 2019 CBC and the PTI Method (PTI; 2014, 2013, 2012).

TABLE 1 - POST-TENSION FOUNDATION DESIGN
DESIGN EXPANSION POTENTIAL
PARAMETER(4) CATEGORY I CATEGORY II
VERY LOW TO LOW(5),(E.I. 0-50) MEDIUM(5) (E.I. 51-90) e,„ center lift 9.0 feet 8.7 feet
e,„ edge lift F 5.0 feet 4.5 feet
y,„ center lift 0.4 inches 0.50 inches
y,„ edge lift 0.7 inch 1.3 inch
Bearing Value (' 1,500 psf ' 1,000 psf(2)
Lateral Pressure 250 psf 250 psf
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TABLE 1 - POST-TENSION FOUNDATION DESIGN

EXPANSION POTENTIAL
DESIGN
PARAMETER(4) CATEGORY I CATEGORY II
VERY LOW TO LOW(S),(E.I. 0-50) MEDIUMS) (E.I. 51-90) Subgrade Modulus (k) 100 pci/inch 85 pci/inch Minimum Perimeter
Footing Embedment(3) 12 inches 18 inches
Internal bearing values within the perimeter of the post-tension slab for very low to low expansive soil conditions maybe increased to 2,000 psf for a minimum embedment of 12 inches,then by 20 percent for each additional foot of embedment to a maximum of 2,500 psf.
'z'For medium expansive soil conditions,internal bearing values within the perimeter of the post-tension slab may be increased to 2,000 psf for a minimum embedment of 12 inches,then by 20 percent for each additional foot of embedment to a maximum of 2,500 psf.
(')As measured below the lowest adjacent compacted subgrade surface(not including slab underlayment layer thickness). '4,Post-tension slab design should also be evaluated with respect to the potential differential settlements provided in this report. ("Category Criteria:

Category I Expansion Index< 50(very low to low),and/or Max fill less than 25 feet thick,or fill differential less than 10 feet.

Category 11 Expansion Index 51-90(Medium),and/or max fill less 25 feet thick,or fill differential less than 20 feet.

Deepened footings/edges around the slab perimeter must be used to minimize non-uniform surface moisture migration (from an outside source) beneath the slab. An edge depth of 12 inches should be considered a minimum. The bottom of the deepened footing/edge should be designed to resist tension, using cable or reinforcement per the structural engineer.

The parameters are considered minimums and may not be adequate to represent all expansive soils/drainage conditions such as adverse drainage and/or improper landscaping and maintenance. The above parameters are applicable provided the structure has positive drainage that is maintained away from the structure. In addition, no trees with significant root systems are to be planted within 15 feet of the perimeter of foundations. Therefore, it is important that information regarding drainage, site maintenance, trees, settlements, and effects of expansive soils be passed on to future all interested/affected parties. The values tabulated above may not be appropriate to account for possible differential settlement of the slab due to other factors, such as excessive settlements. If a stiffer slab is desired, alternative Post-Tensioning Institute QPTI] third edition) parameters may be recommended.

Confirmation Testing for Final Foundation Design
Following the completion of site grading, the expansion index, plasticity index, subgrade modulus, and corrosion potential of soils exposed near finish grade should be re-evaluated. The results of the recommended testing would supercede these preliminary recommendations.

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SOIL MOISTURE TRANSMISSION CONSIDERATIONS
GSI has evaluated the potential for vapor or water transmission through the concrete floor slab, in light of typical floor coverings and improvements. Please note that slab moisture emission rates range from about 2 to 27 Ibs/24 hours/1,000 square feet from a typical slab (Kanare, 2005), while floor covering manufacturers generally recommend about 3 Ibs/24 hours as an upper limit. The recommendations in this section are not intended to preclude the transmission of water or vapor through the foundation or slabs.

Foundation systems and slabs shall not allow water or water vapor to enter into the structure so as to cause damage to another building component or to limit the installation of the type of flooring materials typically used for the particular application (State of California, 2021). These recommendations may be exceeded or supplemented by a water "proofing" specialist, project architect, or structural consultant. Thus,the client will need to evaluate the following in light of a cost vs. benefit analysis (owner expectations and repairs/replacement), along with disclosure to all interested/affected parties. It should also be noted that vapor transmission will occur in new slab-on-grade floors as a result of chemical reactions taking place within the curing concrete. Vapor transmission through concrete floor slabs as a result of concrete curing has the potential to adversely affect sensitive floor coverings depending on the thickness of the concrete floor slab and the duration of time between the placement of concrete, and the floor covering. It is possible that a slab moisture sealant may be needed prior to the placement of sensitive floor coverings if a thick slab-on-grade floor is used and the time frame between concrete and floor covering placement is relatively short.

Considering the E.I. test results presented herein, and known soil conditions in the region, the anticipated typical water vapor transmission rates,floor coverings, and improvements (to be chosen by the Client and/or project architect) that can tolerate vapor transmission rates without significant distress, the following alternatives are provided:
• Concrete slabs should be increased in thickness.
• Concrete slab underlayment should consist of a 15-mil vapor retarder, or equivalent, with all laps sealed per the 2019 CBC and the manufacturer's recommendation.

The vapor retarder should comply with the ASTM E 1745 - Class A criteria, and be installed in accordance with ACI 302.1 R-04 and ASTM E 1643. • The 15-mil vapor retarder (ASTM E 1745 - Class A) shall be installed per the recommendations of the manufacturer, including aII penetrations(i.e., pipe,ducting, rebar, etc.).
• Concrete slabs, including the garage areas, shall be underlain by 2 inches of clean, washed sand (SE > 30) above a 15-mil vapor retarder (ASTM E-1745 - Class A, per Engineering Bulletin 119 [Kanare, 2005]) installed per the recommendations of the manufacturer, including all penetrations (i.e., pipe, ducting, rebar, etc.). The Mr. Zoran Djordjevich W.O. 8058-A-SC
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manufacturer shall provide instructions for lap sealing, including minimum width of lap, method of sealing, and either supply or specify suitable products for lap sealing (ASTM E 1745), and per Code.

ACI 302.1 R-04 (2004) states "If a cushion or sand layer is desired between the vapor retarder and the slab, care must be taken to protect the sand layer from taking on additional water from a source such as rain, curing, cutting, or cleaning.

Wet cushion or sand layer has been directly linked in the past to significant lengthening of time required for a slab to reach an acceptable level of dryness for floor covering applications." Therefore,additional observation and/or testing will be necessary for the cushion or sand layer for moisture content, and relatively uniform thicknesses, prior to the placement of concrete.
• The vapor retarder shall be underlain by 2 inches of sand (SE > 30) placed directly on the prepared, moisture conditioned, subgrade and should be sealed to provide a continuous retarder under the entire slab, as discussed above. As discussed previously, GSI indicated this layer of import sand may be eliminated below the vapor retarder, if laboratory testing indicates that the slab subgrade soil have a sand equivalent (SE) of 30 or greater.
• Concrete should have a maximum water/cement ratio of 0.50. This does not supercede Table 19.3.2.1 of ACI (2014) for corrosion or other corrosive requirements. Additional concrete mix design recommendations should be provided by the structural consultant and/or waterproofing specialist. Concrete finishing and workablity should be addressed by the structural consultant and a waterproofing specialist.
• Where slab water/cement ratios are as indicated herein, and/or admixtures used, the structural consultant should also make changes to the concrete in the grade beams and footings in kind, so that the concrete used in the foundation and slabs are designed and/or treated for more uniform moisture protection. • The owner(s)should be specifically advised which areas are suitable for tile flooring, vinyl flooring, or other types of water/vapor-sensitive flooring and which are not suitable. In all planned floor areas, flooring shall be installed per the manufactures recommendations.
• Additional recommendations regarding water or vapor transmission should be provided by the architect/structural engineer/slab or foundation designer and should be consistent with the specified floor coverings indicated by the architect.

Regardless of the mitigation, some limited moisture/moisture vapor transmission through the slab should be anticipated. Construction crews may require special training for installation of certain product(s), as well as concrete finishing techniques. The use of specialized product(s) should be approved by the slab designer and water-proofing Mr. Zoran Djordjevich W.O. 8058-A-SC
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consultant. A technical representative of the flooring contractor should review the slab and moisture retarder plans and provide comment prior to the construction of the foundations or improvements. The vapor retarder contractor should have representatives onsite during the initial installation.

WALL DESIGN PARAMETERS
Conventional Retaining Walls
The design parameters provided below assume that either non expansive soils (typically Class 2 permeable filter material or Class 3 aggregate base) or native onsite materials (up to and including an E.I. of 35) are used to backfill any retaining walls. The type of backfill (i.e., select or native), should be specified by the wall designer, and clearly shown on the plans. Building walls, below grade, should be water-proofed. To reduce the potential for site retaining walls to suffer efflorescence staining, they may also be water-proofed. The foundation system forthe proposed retaining walls should be designed in accordance with the recommendations presented in this and preceding sections of this report, as appropriate. Recommendations for specialty walls(i.e., crib, earthstone,geogrid,etc.) can be provided upon request, and would be based on site specific conditions.

Preliminary Retaining Wall Foundation Design
Preliminary foundation design for retaining walls should incorporate the following recommendations:

Minimum Footing Embedment - 18 inches below the lowest adjacent grade (excluding landscape layer [upper 6 inches]).

Minimum Footing Width - 24 inches.

Allowable Bearing Pressure -An allowable bearing pressure of 2,500 pcf may be used in the preliminary design of retaining wall foundations provided thatthefooting maintains a minimum width of 24 inches and extends at least 18 inches into approved engineered fill overlying dense formational materials (excluding the top 6 inches [landscape zone]). This pressure may be increased by one-third for short-term wind and/or seismic loads.

Passive Earth Pressure - A passive earth pressure of 250 pcf with a maximum earth pressure of 2,500 psf may be used in the preliminary design of retaining wall foundations provided the foundation is embedded into properly compacted silty to clayey sand fill.

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Lateral Sliding Resistance-A coefficient of 0.25 pcf may be utilized for a concrete to soil contact when multiplied by the dead load. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third.

Backfill Soil Density- Soil densities ranging between 120 pcf and 125 pcf may be used in the design of retaining wall foundations. This assumes an average engineered fill compaction of at least 90 percent of the laboratory standard (ASTM D 1557).

Any retaining wall footings near the perimeter of the site will likely need to be deepened into relatively unweathered granitic bedrock for adequate vertical and lateral bearing support. All retaining wall footing setbacks from slopes should comply with Figure 1808.7.1 of the 2019 CBC. GSI recommends a minimum horizontal setback distance of 7 feet as measured from the bottom, outboard edge of the footing to the slope face.

Restrained Walls
Any retaining walls that will be restrained prior to placing and compacting backfill material or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid pressure (EFP) of 55 pcf and 65 pcf for select and very low expansive native backfill, respectively. The design should include any applicable surcharge loading. For areas of male or re-entrant corners, the restrained wall design should extend a minimum distance of twice the height of the wall (2H) laterally from the corner.

Cantilevered Walls
The recommendations presented below are for cantilevered retaining walls up to 10 feet high. Design parameters for walls less than 3 feet in height may be superceded by County of San Diego regional standard design. Active earth pressure may be used for retaining wall design, provided the top of the wall is not restrained from minor deflections. An equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are given below for specific slope gradients of the retained material. These do not include other superimposed loading conditions due to traffic, structures, seismic events or adverse geologic conditions. When wall configurations are finalized,the appropriate loading conditions for superimposed loads can be provided upon request.

For preliminary planning purposes, the structural consultant/wall designer should incorporate the surcharge of traffic on the back of retaining walls where vehicular traffic could occur within horizontal distance "H" from the back of the retaining wall (where "H" equals the wall height). The traffic surcharge may be taken as 100 psf/ft in the upper 5 feet of backfill for light truck and cars traffic. This does not include the surcharge of parked Mr. Zoran Djordjevich W.O. 8058-A-SC
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vehicles which should be evaluated at a higher surcharge to account for the effects of seismic loading. Equivalent fluid pressures for the design of cantilevered retaining walls are provided in the following table:

SURFACE SLOPE OF EQUIVALENT EQUIVALENT
RETAINED MATERIAL FLUID WEIGHT P.C.F. FLUID WEIGHT P.C.F. (HORIZONTAL:VERTICAL) (SELECT BACKFILL)(2) (SELECT NATIVE BACKFILL)(3) Level(') I 38 I 50
2 to 1 55 65
Level backfill behind a retaining wall is defined as compacted earth materials, properly drained,without a slope for a distance of 2H behind the wall, where H is the height of the wall. (2) SE > 30, P.I. 25, P.I. < 15, E.I. < 21, and < 20% passing No. 200 sieve (may not be sufficiently present onsite).

Seismic Surcharge
For engineered retaining walls, GSI recommends that the walls be evaluated for a seismic surcharge (in general accordance with 2019 CBC requirements), should walls be within 6 feet of ingress/egress areas. The site walls in this category should maintain an overturning factor-of-safety (FOS) of approximately 1 .25 when the seismic surcharge (increment), is applied. For restrained walls, the seismic surcharge should be applied as a uniform surcharge load from the bottom of the footing (excluding shear keys) to the top of the backfill at the heel of the wall footing. This seismic surcharge pressure (seismic increment) may be taken as 15H where "H" for retained walls is the dimension previously noted as the height of the backfill to the bottom of the footing. The resultant force should be applied at a distance 0.6 H up from the bottom of the footing. For the evaluation of the seismic surcharge, the bearing pressure may exceed the static value by one-third, considering the transient nature of this surcharge. For cantilevered walls the pressure should be an inverted triangular distribution using 15H. Please note this is for local wall stability only.

The 15H is derived from a Mononobe-Okabe solution for both restrained cantilever walls.

This accounts for the increased lateral pressure due to shakedown or movement of the sand fill soil in the zone of influence from the wall or roughly a 45' - �/2 plane away from the back of the wall. The 15H seismic surcharge is derived from the formula:

Ph = 3/8 • ah • ytH
Where: Ph = Seismic increment
ah = Probabilistic horizontal site acceleration with a percentage of «g„
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Yt total unit weight (115 to 125 pcf for site soils @ 90% relative compaction).

H Height of the wall from the bottom of the footing or point of pile fixity.

Retaining Wall Backfill and Drainage
Positive drainage must be provided behind all retaining walls in the form of gravel wrapped in geofabric and outlets. A backdrain system is considered necessary for retaining walls that are 2 feet or greater in height. Details 1, 2, and 3, present the back drainage options discussed below. Backdrains should consist of a 4-inch diameter perforated PVC or ABS pipe encased in either Class 2 permeable filter material or 3/4-inch to 1'/2-inch gravel wrapped in approved filter fabric (Mirafi 140 or equivalent). For low expansive backfill, the filter material should extend a minimum of 1 horizontal foot behind the base of the walls and upward at least 1 foot. For native backfill that has up to medium expansion potential, continuous Class 2 permeable drain materials should be used behind the wall. This material should be continuous (i.e., full height) behind the wall, and it should be constructed in accordance with the enclosed Detail 1 (Typical Retaining Wall Backfill and Drainage Detail). For limited access and confined areas, (panel) drainage behind the wall may be constructed in accordance with Detail 2 (Retaining Wall Backfill and Subdrain Detail Geotextile Drain). Materials with an E.I. potential of greater than 50 should not be used as backfill for retaining walls. For more onerous expansive situations, backfill and drainage behind the retaining wall should conform with Detail 3 (Retaining Wall And Subdrain Detail Clean Sand Backfill).

Drain outlets should consist of a 4-inch diameter solid PVC or ABS pipe spaced no greater than ±100 feet apart, with a minimum of two outlets, one on each end. The use of weep holes, only, in walls higher than 2 feet, is not recommended. The surface of the backfill should be sealed by pavement or the top 18 inches compacted with native soil (E.I. <50).

Proper surface drainage should also be provided. For additional mitigation, consideration should be given to applying a water-proof membrane to the back of all retaining structures.

The use of a waterstop should be considered for all concrete and masonry joints.

Wall/Retaining Wall Footing Transitions
Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Should wall footings transition from cut to fill, the civil designer may specify either:
a) A minimum of a 2-foot overexcavation and recompaction of cut materials for a distance of 2H, from the point of transition.
b) Increase of the amount of reinforcing steel and wall detailing (i.e., expansion joints or crack control joints) such that a angular distortion of 1/360 for a distance of 2H Mr. Zoran Djordjevich W.O. 8058-A-SC
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Structural footing or
settlement-sensitive improvement
Provide surface drainage via an
(1) Waterproofing engineered V-ditch (see civil plans membrane for details)
CMU or 2:1 NO slope
reinforced-concrete
wall
Slope"or level: .
±12 inches �\
12:inches i
(2) :Gravel..

Proposed grade :. .
sloped to drain
er recise civil 0) Filter fabri
p p / Native backfill
drawings
(5) Weep hole o 0

4. .Pipe
�\� � 1:1 NO or flatter
��� ����\� backcut to be
Footing and wall properly benched
design by others
(6) Footing
(1) Waterproofing membrane.
(2) Gravel: Clean, crushed, 34 to 112 inch.
(3) Filter fabric Mirafi 140N or approved equivalent.
(4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient sloped to suitable, approved outlet point (perforations down). (5) Weep hole: Minimum 2-inch diameter placed at 20-foot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall.

No weep holes for below-grade walls.
(6) Footing: If bench is created behind the footing greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical consultant.

G RETAINING WALL DETAIL — ALTERNATIVE A Detail 1 L

Structural footing or
(1) Waterproofing settlement-sensitive improvement membrane (optional)- Provide surface drainage via engineered V-ditch (see civil plan details)
CMU or 2:1 NO slope
reinforced-concrete
wall .. ..

Slope or..:1.evel
6 inches �\
(2) :Composite..
drain
(5) Weep hole
Proposed grade (3) .Filter fabri
p g , — Native backfill
sloped to drain
per precise civil
drawings (4) pipe h v or flatter
i\ ( )
backcut to be
Footing and wall
properly benched
design by others - (6) 1 cubic foot of
3 4-inch crushed rock
(7) Footing
(1) Waterproofing membrane (optional): Liquid boot or approved mastic equivalent. (2) Drain: Miradrain 6000 or J-drain 200 or equivalent for non-waterproofed walls; Miradrain 6200 or J-drain 200 or equivalent for waterproofed walls (all perforations down). (3) Filter fabric: Mirafi 140N or approved equivalent; place fabric flap behind core. (4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient to proper outlet point (perforations down). (5) Weep hole: Minimum 2-inch diameter placed at 20-foot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall.

No weep holes for below-grade walls.
(6) Gravel: Clean, crushed, 34 to 112 inch.
(7) Footing: If bench is created behind the footing greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical consultant.

G� nc. RETAINING WALL DETAIL — ALTERNATIVE B Detail 2

(1) Waterproofing Structural footing or
membrane settlement-sensitive improvement
Provide surface drainage
CMU or — 2:1 (h:v) slope
reinforced-concrete
wall
Slope or level
±12 inches iriinimumII \�
(5) Weep hole j \
" Proposed grade (8) Native backfill
sloped to drain ,;,;,;,;,;,;,;,;,;,;,;,;,;,;,;,;,; ,\ (6) Clean per precise civil sand backfill
drawings ,\\
\ �\\ ��� o . . . . . . . . . . . 1:1 NO or flatter . backcut to be
(3) Filter fabric properly benched
Footing and wall (2) Gravel
design by others Heel
I�idt (4) Pipe
(7) Footing
(1) Waterproofing membrane: Liquid boot or approved masticequivalent. (2) Gravel: Clean, crushed, 34 to 112 inch.
(3) Filter fabric: Mirafi 140N or approved equivalent. (4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient to proper outlet point (perforations down). (5) Weep hole: Minimum 2-inch diameter placed at 20-foot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall.

No weep holes for below-grade walls.
(6) Clean sand backfill Must have sand equivalent value (S.E.) of 35 or greater; can be densified by water jetting upon approval by geotechnical engineer. (7) Footing: If bench is created behind the footing greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical consultant.
(8) Native backfill: If E.I. 35 then all sand requirements also may not be required and will be reviewed by the geotechnical consultant.

G ill�C. RETAINING WALL DETAIL — ALTERNATIVE C Detail 3 —4�0�L

on either side of the transition may be accommodated. Expansion joints should be placed no greater than 20 feet on-center, in accordance with the structural engineer's/wall designer's recommendations, regardless of whether or not transition conditions exist. Expansion joints should be sealed with aflexible, non-shrink grout.

C) Embed the footings entirely into native formational material (i.e., deepened footings).

If transitions from cut to fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should follow recommendation "a" (above) and until such transition is between 45 and 90 degrees to the wall alignment.

DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS
Some of the soil materials on site may be expansive. The effects of expansive soils are cumulative, and typically occur over the lifetime of any improvements. On relatively level areas, when the soils are allowed to dry, the dessication and swelling process tends to cause heaving and distress to flatwork and other improvements. The resulting potential for distress to improvements may be reduced, but not totally eliminated. To that end, it is recommended that the Client should notify all interested/affected parties of this long-term potential for distress. To reduce the likelihood of distress,the following recommendations are presented for all exterior flatwork:

1. The subgrade area for concrete slabs should be compacted to achieve a minimum 90 percent relative compaction, and then be presoaked to 1 to 2 percentage points above (or 110 percent of) the soils' optimum moisture content, to a depth of 18 inches below subgrade elevation. If very low expansive soils are present, only optimum moisture content, or greater, is required and specific presoaking is not warranted. The moisture content of the subgrade should be proof tested within 72 hours prior to concrete placement.

2. Exterior concrete slabs should be cast over a non-yielding surface, consisting of a 4-inch layer of Class 3 base, crushed rock, gravel, or clean sand (or City of Vista minimum, whichever is greater), that should be compacted and level prior to placement of concrete. If very low expansive soils are present, the base, rock, gravel, or sand may be deleted. The layer or subgrade should be wet-down completely prior to placement of concrete, to minimize loss of concrete moisture to the surrounding earth materials.

3. Exterior slabs should be a minimum of 4 inches thick. Driveway slabs and approaches should additionally have a thickened edge (12 inches) adjacent to all landscape areas, to help impede infiltration of landscape water under the slab.

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4. The use of transverse and longitudinal control joints are recommended to help control slab cracking due to concrete shrinkage or expansion. Two ways to mitigate such cracking are: a) add a sufficient amount of reinforcing steel, increasing tensile strength of the slab; and, b) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion.

In order to reduce the potential for unsightly cracks, slabs should be reinforced at mid-height with a minimum of No. 3 bars placed at 18 inches on center, in each direction. The exterior slabs should be scored or saw cut, 1/2 to 3/8 inches deep, often enough so that no section is greater than 10 feet by 10 feet. For sidewalks or narrow slabs, control joints should be provided at intervals of every 6 feet. The slabs should be separated from the foundations and sidewalks with expansion joint filler material.

5. No traffic should be allowed upon the newly poured concrete slabs until they have been properly cured to within 75 percent of design strength. Concrete compression strength should be a minimum of 2,500 psi.

6. Driveways, sidewalks, and patio slabs adjacent to the house should be separated from the house with thick expansion joint filler material. In areas directly adjacent to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints should be additionally sealed with flexible mastic.

7. Planters and walls should not be tied to the house.

8. Overhang structures should be supported on the slabs, or structurally designed with continuous footings tied in at least two directions.

9. Any masonry landscape walls that are to be constructed throughout the property should be grouted and articulated in segments no more than 20 feet long. These segments should be keyed or doweled together.

10. Utilities should be enclosed within a closed utilidor (vault) or designed with flexible connections to accommodate differential settlement and expansive soil conditions.

11. Positive site drainage should be maintained at all times. Finish grade on the lots should provide a minimum of 1 to 2 percent fall to the street, as indicated herein.

It should be kept in mind that drainage reversals could occur, including post-construction settlement, if relatively flat yard drainage gradients are not periodically maintained by the homeowner or homeowners association.

12. Air conditioning (A/C) units should be supported by slabs that are incorporated into the building foundation or constructed on a rigid slab with flexible couplings for Mr. Zoran Djordjevich W.O. 8058-A-SC
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plumbing and electrical lines. A/C waste water lines should be drained to a suitable non-erosive outlet.

13. Shrinkage cracks could become excessive if proper finishing and curing practices are not followed. Finishing and curing practices should be performed per the Portland Cement Association Guidelines. Mix design should incorporate rate of curing for climate and time of year, sulfate content of soils, corrosion potential of soils, and fertilizers used on site.

PRELIMINARY ASPHALTIC CONCRETE

PAVEMENT DESIGN RECOMMENDATIONS
General
The City of Vista may retain the authority to approve the final structural design sections after subgrade elevations and actual resistance values (R-values) have been obtained at the conclusion of earthwork. Based on an assumed R-value of 20, a review of City of Vista street design criteria (City of Vista, 2015), and for estimation and bidding purposes, the asphaltic concrete pavement section for the planned driveway, provided herein,should be considered for preliminary design. Typically, actual pavement sections will likely vary, therefore final pavement sections should be based on actual R-value testing performed following the backfill of underground utilities in the street right-of-way.

The preliminary pavement sections presented in the following table are based on the general Traffic Indices (T.I.), utilized by the City of Vista for residential local and cul-de-sac streets, and the guidelines presented in the latest revision to the California Department of Transportation "Highway Design Manual" seventh edition. Based on an assumed R-value of 20 and a T.I. value of 6.0 for cul-de-sac and local streets, the following preliminary asphaltic concrete pavement designs are presented. Based on the fine-grained nature of some of the onsite soils, an R-value of 20 was used in the analysis for reasonable conservatism.

STANDARD PAVEMENT DESIGNS
STREET TRAFFIC AC* CLASS

AGGREGATE
CLASSIFICATION I INDEX (T.I.)(') R-VALUE INCHES BASE NCHES Cul-de-sac/Local 6.0 20 4.0 8.0
I' City of Vista (2015)
2 Assumed R-values for Class 2 aggregate base R=78 - Cal-Trans standard Class 2 Aggregate Base.

The preliminary pavement section provided above is intended as a minimum guideline.

If thinner or highly variable pavement sections are constructed, increased maintenance Mr. Zoran Djordjevich W.O. 8058-A-SC
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and repair could be expected. If the ADT (average daily traffic) or ADTT (average daily truck traffic) increases beyond that intended, as reflected by the T.I. used for design, increased maintenance and repair could be required for the pavement section.

Consideration should be given to the increased potential for distress from overuse of paved street areas by heavy equipment and/or construction related heavy traffic (e.g., concrete trucks, loaded supply trucks, etc.), particularly when the final section is not in place (i.e., topcoat). Best management construction practices should be followed at all times, especially during inclement weather.

PAVEMENT GRADING RECOMMENDATIONS
General
All section changes should be properly transitioned. If adverse conditions are encountered during the preparation of subgrade materials, special construction methods may need to be employed. A GSI representative should be present for the preparation of subgrade, aggregate base, and asphaltic concrete.

Subgrade
Within street and parking areas, all surficial deposits of loose soil material should be removed and recompacted as recommended. After the loose soils are removed, the bottom is to be scarified to a depth of at least 6 inches, moisture conditioned as necessary and compacted to 95 percent of the maximum laboratory density, as determined by ASTM D 1557.

Deleterious material,excessively wet or dry pockets, concentrated zones of oversized rock fragments, and any other unsuitable materials encountered during grading should be removed. The compacted fill material should then be brought to the elevation of the proposed subgrade for the pavement. The subgrade should be proof-rolled in order to promote a uniform firm and unyielding surface. All grading and fill placement should be observed by the project geotechnical consultant.

Aggregate Base
Compaction tests are required for the recommended aggregate base section. Minimum relative compaction required will be 95 percent of the laboratory maximum density as determined by ASTM D 1557. Base aggregate should be in accordance to the "Greenbook" crushed aggregate base rock (minimum R-value=78).

Paving
Prime coat may be omitted if all of the following conditions are met:

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1. The asphalt pavement layer is placed within two weeks of completion of aggregate base and/or subbase course.

2. Traffic is not routed over completed base before paving

3. Construction is completed during the dry season of May through October.

4. The aggregate base is kept free of debris prior to placement of asphaltic concrete.

If construction is performed during the wet season of November through April, prime coat may be omitted if no rain occurs between completion of the aggregate base course and paving and the time between completion of aggregate base and paving is reduced to three days, provided the aggregate base is free of loose soil or debris. Where prime coat has been omitted and rain occurs, traffic is routed over the aggregate base course, or paving is delayed, measures shall be taken to restore the aggregate base course, and subgrade to conditions that will meet specifications as directed by the geotechnical consultant.

Drainage
Positive drainage should be provided for all surface water to drain towards the area swale, curb and gutter, or to an approved drainage channel. Positive site drainage should be maintained at all times. Water should not be allowed to pond or seep into the ground, such as from behind unprotected curbs, both during and after grading. If planters or landscaping are adjacent to paved areas, measures should be taken to minimize the potential for water to enter the pavement section, such as thickened edges, enclosed planters, etc. Also, best management construction practices should be strictly adhered to at all times to minimize the potential for distress during construction and roadway improvements.

PCC Cross Gutters
PCC cross gutters should be designed in accordance with San Diego Regional Standard Drawing (SDRSD) G-12.

Additional Considerations
To mitigate perched groundwater, consideration should be given to installation of subgrade separators (cut-offs) between pavement subgrade and landscape areas, although this is not a requirement from a geotechnical standpoint. Cut-offs, if used, should be 6 inches wide and at least 12 inches below the pavement subgrade contact or 12 inches below the crushed aggregate base rock, if utilized.

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DEVELOPMENT CRITERIA
Slope Maintenance and Planting
Water has been shown to weaken the inherent strength of all earth materials. Slope stability is significantly reduced by overly wet conditions. Positive surface drainage away from slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Over-watering should be avoided as it adversely affects site improvements,and causes perched groundwater conditions. Graded slopes constructed utilizing onsite materials would be erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Compaction to the face of fill slopes would tend to minimize short-term erosion until vegetation is established. Plants selected for landscaping should be light weight, deep rooted types that require little water and are capable of surviving the prevailing climate. Jute-type matting or other fibrous covers may aid in allowing the establishment of a sparse plant cover. Utilizing plants other than those recommended above will increase the potential for perched water, staining, mold, etc., to develop. A rodent control program to prevent burrowing should be implemented.

Irrigation of natural (ungraded) slope areas is generally not recommended. These recommendations regarding plant type, irrigation practices, and rodent control should be provided to each homeowner. Over-steepening of slopes should be avoided during building construction activities and landscaping.

Drainage
Adequate surface drainage is a very important factor in reducing the likelihood of adverse performance of foundations, hardscape,and slopes. Surface drainage should be sufficient to mitigate ponding of water anywhere on the property, and especially near structures and tops of slopes. Surface drainage should be carefully taken into consideration during fine grading, landscaping, and building construction. Therefore, care should be taken that future landscaping or construction activities do not create adverse drainage conditions.

Positive site drainage within the property should be provided and maintained at all times.

Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and tops of slopes, and not allowed to pond and/or seep into the ground. In general, site drainage should conform to Section 1804.3 of the 2019 CBC. Consideration should be given to avoiding construction of planters adjacent to structures (buildings, pools, spas, etc.). Building pad drainage should be directed toward the street or other approved area(s). Although not a geotechnical requirement, roof gutters, down spouts, or other appropriate means may be utilized to control roof drainage. Down spouts, or drainage devices should outlet a minimum of 5 feet from structures or into a subsurface drainage system. Areas of seepage may develop due to irrigation or heavy rainfall, and should be anticipated. Minimizing irrigation will lessen this potential. If areas of seepage develop, recommendations for minimizing this effect could be provided upon request.

Mr. Zoran Djordjevich W.O. 8058-A-SC
1205 Melrose Way, Vista March 5, 2021
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Erosion Control
Onsite earth materials have a moderate to high erosion potential. Consideration should be given to providing hay bales and silt fences for the temporary control of surface water, from a geotechnical viewpoint.

Landscape Maintenance
Only the amount of irrigation necessary to sustain plant life should be provided.

Over-watering the landscape areas will adversely affect proposed site improvements. We would recommend that any proposed open-bottom planters adjacent to proposed structures be eliminated for a minimum distance of 10 feet. As an alternative, closed-bottom type planters could be utilized. An outlet placed in the bottom of the planter, could be installed to direct drainage away from structures or any exterior concrete flatwork. If planters are constructed adjacent to structures, the sides and bottom of the planter should be provided with a moisture barrier to prevent penetration of irrigation water into the subgrade. Provisions should be made to drain the excess irrigation water from the planters without saturating the subgrade below or adjacent to the planters. Graded slope areas should be planted with drought resistant vegetation. Consideration should be given to the type of vegetation chosen and their potential effect upon surface improvements (i.e., some trees will have an effect on concrete flatwork with their extensive root systems).

From a geotechnical standpoint leaching is not recommended for establishing landscaping. If the surface soils are processed for the purpose of adding amendments, they should be recompacted to 90 percent minimum relative compaction.

Gutters and Downspouts
As previously discussed in the drainage section,the installation of gutters and downspouts should be considered to collect roof water that may otherwise infiltrate the soils adjacent to the structures. If utilized, the downspouts should be drained into PVC collector pipes or other non-erosive devices (e.g., paved swales or ditches; below grade, solid tight-lined PVC pipes; etc.), that will carry the water away from the house, to an appropriate outlet, in accordance with the recommendations of the design civil engineer. Downspouts and gutters are not a requirement; however, from a geotechnical viewpoint, provided that positive drainage is incorporated into project design (as discussed previously).

Subsurface and Surface Water
Subsurface and surface water are not anticipated to affect site development, provided that the recommendations contained in this report are incorporated into final design and construction and that prudent surface and subsurface drainage practices are incorporated into the construction plans. Perched groundwater conditions along zones of contrasting permeabilities may not be precluded from occurring in the future due to site irrigation, poor drainage conditions, or damaged utilities, and should be anticipated. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide Mr. Zoran Djordjevich W.O. 8058-A-SC
1205 Melrose Way, Vista March 5, 2021
File:e:\wp12\8000\8058a.gep GeoSoils, Inc. Page 45

the appropriate recommendations to mitigate the observed groundwater conditions.

Groundwater conditions may change with the introduction of irrigation, rainfall, or other factors.

Site Improvements
If in the future, any additional improvements (e.g., pools, spas, etc.) are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. Pools and/or spas should not be constructed without specific design and construction recommendations from GSI, and this construction recommendation should be provided to all interested/affected parties. Rock fills may not be suitable for supporting pools/spa. This office should be notified in advance of any fill placement, grading of the site, or trench backfilling after rough grading has been completed. This includes any grading, utility trench and retaining wall backfills, flatwork, etc.

Tile Flooring
Tile flooring can crack, reflecting cracks in the concrete slab below the tile, although small cracks in a conventional slab may not be significant. Therefore, the designer should consider additional steel reinforcement for concrete slabs-on-grade where tile will be placed. The tile installer should consider installation methods that reduce possible cracking of the tile such as slipsheets. Slipsheets or a vinyl crack isolation membrane (approved by the Tile Council of America/Ceramic Tile Institute) are recommended between tile and concrete slabs on grade.

Additional Grading
This office should be notified in advance of any fill placement, supplemental regrading of the site, or trench backfilling after rough grading has been completed. This includes completion of grading in the street, driveway approaches, driveways, parking areas, and utility trench and retaining wall backfills.

Footing Trench Excavation
All footing excavations should be observed by a representative of this firm subsequent to trenching and rior to concrete form and reinforcement placement. The purpose of the observations is to evaluate that the excavations have been made into the recommended bearing material and to the minimum widths and depths recommended for construction.

If loose or compressible materials are exposed within the footing excavation, a deeper footing or removal and recompaction of the subgrade materials would be recommended at that time. Footing trench spoil and any excess soils generated from utility trench excavations should be compacted to a minimum relative compaction of 90 percent, if not removed from the site.

Mr. Zoran Djordjevich W.O. 8058-A-SC
1205 Melrose Way, Vista March 5, 2021
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Trenching/Temporary Construction Backcuts
Considering the nature of the onsite earth materials, it should be anticipated that caving or sloughing could be a factor in subsurface excavations and trenching. Shoring or excavating the trench walls/backcuts at the angle of repose (typically 25 to 45 degrees [except as specifically superceded within the text of this report]), should be anticipated.

All excavations should be observed by an engineering geologist or soil engineer from GSI, prior to workers entering the excavation or trench, and minimally conform to CAL-OSHA, state, and local safety codes. Should adverse conditions exist, appropriate recommendations would be offered at that time. The above recommendations should be provided to any contractors and/or subcontractors,or homeowners, etc.,that may perform such work.

Utility Trench Backfill

1. All interior utility trench backfill should be brought to at least 2 percent above optimum moisture content and then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. As an alternative for shallow (12-inch to 18-inch) under-slab trenches, sand having a sand equivalent value of 30 or greater may be utilized and jetted or flooded into place. Observation, probing and testing should be provided to evaluate the desired results.

2. Exterior trenches adjacent to, and within areas extending below a 1 :1 plane projected from the outside bottom edge of the footing, and all trenches beneath hardscape features and in slopes, should be compacted to at least 90 percent of the laboratory standard. Sand backfill, unless excavated from the trench, should not be used in these backfill areas. Compaction testing and observations, along with probing, should be accomplished to evaluate the desired results.

3. All trench excavations should conform to CAL-OSHA, state, and local safety codes.

4. Utilities crossing grade beams, perimeter beams, or footings should either pass below the footing or grade beam utilizing a hardened collar or foam spacer, or pass through the footing or grade beam in accordance with the recommendations of the structural engineer.

SUMMARY OF RECOMMENDATIONS REGARDING

GEOTECHNICAL OBSERVATION AND TESTING
We recommend that observation and/or testing be performed by GSI at each of the following construction stages:
• During grading/recertification.

Mr. Zoran Djordjevich W.O. 8058-A-SC
1205 Melrose Way, Vista March 5, 2021
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• During excavation.
• During placement of subdrains or other subdrainage devices, prior to placing fill and/or backfill.
• After excavation of building footings, retaining wall footings, and free standing walls footings, prior to the placement of reinforcing steel or concrete. • Prior to pouring any slabs or flatwork, after presoaking/presaturation of building pads and other flatwork subgrade, before the placement of concrete, reinforcing steel, capillary break (i.e., sand, pea-gravel, etc.), or vapor retarders (i.e., visqueen, etc.).
• During retaining wall subdrain installation, prior to backfill placement. • During placement of backfill for area drain, interior plumbing, underground utility trenches, and retaining wall backfill.
• During slope construction/repair.
• When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report.
• When any homeowner improvements, such as flatwork, spas, pools,walls, etc., are constructed, prior to construction.
• A report of geotechnical observation and testing should be provided at the conclusion of each of the above stages, in order to provide concise and clear documentation of site work, and/or to comply with code requirements.

OTHER DESIGN PROFESSIONALS/CONSULTANTS
The design civil engineer, structural engineer, post-tension designer, architect, landscape architect, wall designer, etc., should review the recommendations provided herein, incorporate those recommendations into all their respective plans, and by explicit reference, make this report part of their project plans. This report presents minimum design criteria for the design of slabs,foundations and other elements possibly applicable to the project. These criteria should not be considered as substitutes for actual designs by the structural engineer/designer. Please note that the recommendations contained herein are not intended to preclude the transmission of water or vapor through the slab or foundation. The structural engineer/foundation and/or slab designer should provide recommendations to not allow water or vapor to enter into the structure so as to cause damage to another building component, or so as to limit the installation of the type of flooring materials typically used for the particular application.

Mr. Zoran Djordjevich W.O. 8058-A-SC
1205 Melrose Way, Vista March 5, 2021
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The structural engineer/designer should analyze actual soil-structure interaction and consider, as needed, bearing, expansive soil influence, and strength, stiffness and deflections in the various slab, foundation, and other elements in order to develop appropriate, design-specific details. As conditions dictate, it is possible that other influences will also have to be considered. The structural engineer/designer should consider all applicable codes and authoritative sources where needed. If analyses by the structural engineer/designer result in less critical details than are provided herein as minimums,the minimums presented herein should be adopted. It is considered likely that some, more restrictive details will be required.

If the structural engineer/designer has any questions or requires further assistance, they should not hesitate to call or otherwise transmit their requests to GSI. In order to mitigate potential distress, the foundation and/or improvement's designer should confirm to GSI and the governing agency, in writing,that the proposed foundations and/or improvements can tolerate the amount of differential settlement and/or expansion characteristics and other design criteria specified herein.

PLAN REVIEW
Final project plans (grading, precise grading,foundation, retaining wall, landscaping,etc.), should be reviewed by this office prior to construction, so that construction is in accordance with the conclusions and recommendations of this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted.

Mr. Zoran Djordjevich W.O. 8058-A-SC
1205 Melrose Way, Vista March 5, 2021
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LIMITATIONS
The materials encountered on the project site and utilized for our analysis are believed representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors.

Inasmuch as our study is based upon our review and engineering analyses and laboratory data, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty, either express or implied, is given. Standards of practice are subject to change with time.

GSI assumes no responsibility or liability for work or testing performed by others, or their inaction; or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properly implemented. Use of this report constitutes an agreement and consent by the user to all the limitations outlined above, notwithstanding any other agreements that may be in place. In addition, this report may be subject to review by the controlling authorities. Thus, this report brings to completion our scope of services for this portion of the project. All samples will be disposed of after 30 days, unless specifically requested by the client, in writing.

Mr. Zoran Djordjevich W.O. 8058-A-SC
1205 Melrose Way, Vista March 5, 2021
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APPENDIX A

REFERENCES
GeoSoils, Inc.

APPENDIX A

REFERENCES
American Concrete Institute, 2014a, Building code requirements for structural concrete (ACI 318-14), and commentary (ACI 318R-14): reported by ACI Committee 318, dated September.
2014b, Building code requirements for concrete thin shells (ACI 318.2-14), and commentary (ACI 318.2R-14), dated September.
2004, Guide for concrete floor and slab construction: reported by ACI Committee 302; Designation ACI 302.1 R-04, dated March 23.

American Society for Testing and Materials (ASTM),1998, Standard practice for installation of water vapor retarder used in contact with earth or granular fill under concrete slabs, Designation: E 1643-98 (Reapproved 2005).
1997, Standard specification for plastic water vapor retarders used in contact with soil or granular fill under concrete slabs, Designation: E 1745-97 (Reapproved 2004).

American Society of Civil Engineers, 2018a, Supplement 1 to Minimum Design Loads and Associated Criteria for Buildings and Other Structures (ASCE/SEI 7-16), first printing, dated December 13.
2018b, Errata for Minimum Design Loads and Associated Criteria for Buildings and Other Structures (ASCE/SEI 7-16), by ASCE, dated July 9. 2017, Minimum design loads and associated criteria and other structures, ASCE Standard ASCE/SEI 7-16, published online June 19.

Blake, Thomas F., 2000a, EQFAULT, A computer program for the estimation of peak horizontal acceleration from 3-D fault sources; Windows 95/98 version. 2000b, EQSEARCH, A computer program for the estimation of peak horizontal acceleration from California historical earthquake catalogs; Updated to December 2009, Windows 95/98 version.

Bozorgnia,Y.,Campbell K.W.,and Niazi, M., 1999,Vertical ground motion: Characteristics, relationship with horizontal component, and building-code implications; Proceedings of the SMIP99 seminar on utilization of strong-motion data, September 15, Oakland, pp. 23-49.

Bryant, W.A., and Hart, E.W., 2007, Fault-rupture hazard zones in California, Alquist-Priolo earthquake fault zoning act with index to earthquake fault zones maps; California Geological Survey, Special Publication 42, interim revision.

GeoSoils, Inc.

California Building Standards Commission, 2019a, California Building Code, California Code of Regulations,Title 24, Part 2,Volume 2 of 2, based on the 2018 International Building Code, effective January 1, 2020.
2019b, California Building Code, California Code of Regulations, Title 24, Part 2, Volume 1 of 2, Based on the 2018 International Building Code, effective January 1 , 2020.

California Geological Survey, 2018, Earthquake Fault Zones, a guide for government agencies, property owners/developers, and geoscience practitioners for assessing fault rupture hazards in California, Special Publication 42, revised.

California Office of Statewide Health Planning and Development (OSHPD), 2019, Seismic design maps, https://seismicmaps.org/ .

Cao, T., Bryant,W.A., Rowshandel, B., Branum, D., and Wills, C.J., 2003,The revised 2002 California probabilistic seismic hazard maps, dated June, http://www.conservation.ca.gov/cgs/rghm/psha/fault_parameters/pdf/Document/ 2002_CA_Hazard_Maps.pdf
Clar, M.L., Bartfield, B.J., O'Conner, T.P., 2004, Stormwater best management practice design guide,volume 3, basin best management practices, US EPA/600/R-04/121 B, dated September.

County of San Diego, Department of Planning and Land Use, 2007, Low impact development (LID) handbook, stormwater management strategies, dated December 31.

City of Vista, 2016, City of Vista BMP design manual for permanent site design, stormwater treatment, and hydromodification management, June 2016 update. ,2015, Land Development Division, City of Vista Standard Drawings, Public and Private Street Design Criteria, Sheets 1-4, Drawing No. SRF-03A-D, dated May.

Hydrologic Solutions, StormChamberTm installation brochure, pgs. 1 through 8, undated.

Jennings, C.W., and Bryant, W.A., 2010, Fault activity map of California, scale 1 :750,000, California Geological Survey, Geologic Data Map No. 6.

Kanare, H.M., 2005, Concrete floors and moisture, Engineering Bulletin 119, Portland Cement Association.

Kennedy, M.P., and Tan, SS.,2007, Geologic map of the Oceanside 30' by 60'quadrangle, California, regional geologic map series, scale 1 :100,000, California Geologic Survey Map No. 2.

Mr. Zoran Djordjevich Appendix A
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2005, Geologic map of the Oceanside 30' by 60' quadrangle, California, regional map series, scale 1 :100,000, California Geologic Survey and United States Geological Survey, website: www.conservation.ca.gov/ cgs/rghm/rgm/preliminary_geologic_maps.html
Pasco Laret Suiter&Associates, 2020, Pre-Application Exhibit, 1205 Melrose Way, Sheet Job No. 3334, 40-scale, dated September 1.

Romanoff, M., 1957, Underground corrosion, originally issued April 1.

Seed, 2005, Evaluation and mitigation of soil liquefaction hazard "evaluation of field data and procedures for evaluating the risk of triggering (or inception) of liquefaction", in Geotechnical earthquake engineering; short course, San Diego, California, April 8-9.

Sowers and Sowers, 1979, Unified soil classification system (After U. S. Waterways Experiment Station and ASTM 02487-667) in Introductory Soil Mechanics, New York.

State of California, 2021, Civil Code, Sections 895 et seq.

State of California Department of Transportation, Division of Engineering Services, Materials Engineering, and Testing Services, Corrosion Technology Branch, 2003, Corrosion Guidelines, Version 1 .0, dated September.

Structural Engineers Association of California (SEAC) and the Office of Statewide Health Planning and Development (OSHPD), 2020, OSHPD Seismic design maps, ( http://seismicmaps.org) .

Tan, S.S., and Giffen, D.G., 1995, Landslide hazards in the northern part of the San Diego Metropolitan area, San Diego County, California, Landslide hazard identification map no.35, Plate 35A, Department of Conservation, Division of Mines and Geology, DMG Open File Report 95-04.

United States Department of Agriculture, National Resources Conservation Service, 2021, Custom soils report for San Diego County area, Djordjevich Soil Map (8058), dated February.
1973, Soil survey, San Diego area, California, Part I and Part II.

Vista Irrigation District, 2016, Section 02000 earthwork (Rev 12/99), in www.vid-h20.org (Publications).

Mr. Zoran Djordjevich Appendix A
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APPENDIX B

BORING LOGS
GeoSoils, Inc.

UNIFIED SOIL CLASSIFICATION SYSTEM CONSISTENCY OR RELATIVE DENSITY Major Divisions Group Typical Names CRITERIA Symbols
Well-graded gravels and gravel-
m N
GW sand mixtures,little or no fines Standard Penetration Test c
o ° Poorly graded gravels and Penetration > o U
ro w o t o GP gravel-sand mixtures,little or no Resistance N Relative >
0 E 2 Z fines (blows/ft) Density
0 °' 0
N
N Silty gravels gravel-sand-silt 0-4 Very loose O > _ GM
o z mixtures
Cn ro
-6 0 3 4-10 Loose
75 m GC Clayey gravels,gravel-sand-clay
mixtures 10-30 Medium
0 2
N o Well-graded sands and gravelly 30 50 Dense 0 0 m SW sands,little or no fines
U 0 0 ca .� U ro > 50 Very dense 0 SP Poorly graded sands and
m ) -) o gravelly sands,little or no fines O L Z
CD o � SM Silty sands,sand-silt mixtures
O U � a L
E 3 u_ SC Clayey sands,sand-clay
mixtures
Inorganic silts,very fine sands, Standard Penetration Test ML rock flour,silty or clayey fine
N sands
CD M -= y Unconfined
v E a Inorganic clays of low to Penetration Compressive -a 0 0 CL medium plasticity,gravelly clays, Resistance N Strength
0o N LT o sandy clays,silty clays,lean (blows/ft) Consistency (tons/ft2) N a Ln clays
0 o
0 ro OL Organic silts and organic silty 30 Hard >4.00 OH plasticity
Highly Organic Soils PT Peat,mucic,and other highly organic soils
3" 3/4" #4 #10 #40 #200 U.S.Standard Sieve Unified Soil Cobbles Gravel Sand Silt or Clay Classification coarse fine coarse medium fine MOISTURE CONDITIONS MATERIAL QUANTITY OTHER SYMBOLS Dry Absence of moisture: dusty,dry to the touch trace 0-5% C Core Sample Slightly Moist Below optimum moisture content for compaction few 5-10% S SPT Sample Moist Near optimum moisture content little 10-25% B Bulk Sample Very Moist Above optimum moisture content some 25-45% o Groundwater Wet Visible free water; below water table Qp Pocket Penetrometer BASIC LOG FORMAT:

Group name,Group symbol,(grain size),color,moisture,consistency or relative density. Additional comments:odor,presence of roots,mica,gypsum, coarse grained particles,etc.

EXAMPLE:

Sand(SP),fine to medium grained, brown,moist,loose,trace silt,little fine gravel,few cobbles up to 4"in size,some hair roots and rootlets.

File:Mgr:c;\SoilClassif.wpd PLATE B-1

GeoSoils, Inc. BORING LOG
PROJECT: DJORDJEVICH
1205 Melrose Way W.O. 8058-A-SC BORING HA-1 SHEET 1 OF 1 DATE EXCAVATED 2-16-21 LOGGED BY: MS APPROX.ELEV.: 368'MSL SAMPLE METHOD: Hand Auger
Sample
U
0 o Material Description
T O
j LL U) "' 2 0
L U N U)
n Y 3 L) m
0 o m D co � Q co
0 CH 0' Or anic mulch.

OLLUVIUM:

CL @ '/2' SILTY CLAY, dark gray brown and dark olive brown, damp to moist, SM soft to medium stiff, lowporosity.

C
WEATHERED GRANITICS:
@ 2' Disintegrates to SILTY/SANDY CLAY, light olive brown and medium 5 brown, damp, stiff; salt and pepper rock fragments, visible quartz grains. @ 2'/2' SILTY SAND, light yellowish brown to pale yellow, damp, medium dense to dense.
3'As per 2'/2; very dense, coarser rock fragments.

Total Depth = 3'/2, Practical Refusal
No Groundwater or Caving Encountered
10 Backfilled 2-16-21
15 20
25 30
0 Standard Penetration Test = Groundwater T Undisturbed, Ring Sample 2 Seepage
GeoSoils, Inc.

PLATE B-2

GeoSoils, Inc. BORING LOG
PROJECT: DJORDJEVICH
1205 Melrose Way W.O. 8058-A-SC BORING HA-2 SHEET 1 OF 1 DATE EXCAVATED 2-16-21 LOGGED BY: MS APPROX.ELEV.: 363'MSL SAMPLE METHOD: Hand Auger
Sample
U
0 o Material Description
T O
j LL U) "' 2 0
L U N U)
n Y 3 L) m
0 o co coD 0 co
CH COLLUVIUM:
@ 0' SILTY CLAY, dark brown, reddish brown, and dark olive brown, dampt to moist, soft; moderate porosity.
@ 1'As per 0'; reddish brown and gray brown, low porosity.

CL @ 1'/2'As per 1'; reddish brown with mixtures of gray brown, medium stiff sC 9dense
5 s per 1'/z'; dry to damp, stiff to very stiff. per 2'/2; SANDY CLAY, reddish brown.

WRED GRANITICS:
integrates to CLAYEY SAND, light reddish brown and gray, dry, very stiff; granitic rock fragments.

Total Depth = 5', Practical Refusal
10 No Groundwater or Caving Encountered
Backfilled 2-16-21
15 20
25 30
0 Standard Penetration Test = Groundwater T Undisturbed, Ring Sample 2 Seepage
GeoSoils, Inc.

PLATE B-3

GeoSoils, Inc. BORING LOG
PROJECT: DJORDJEVICH
1205 Melrose Way W.O. 8058-A-SC BORING HA-3 SHEET 1 OF 1 DATE EXCAVATED 2-16-21 LOGGED BY: MS APPROX.ELEV.: 360'MSL SAMPLE METHOD: Hand Auger&Hand Sampler
Sample
U
0 o Material Description
T O
j LL U) "' 2 0
L U N U)
n Y 3 L) m
0 0 m D coZ) O (n
o sM COLLUVIUM:

CL @ 0' SILTY SAND, dark brown to dark olive brown, moist, medium dense; sM 113.4 13.5 75.1 trace clay, fine to coarse grain sand, sporadic subangular gravels. 1' SANDY CLAY, olive gray, moist, medium stiff.

WEATHERED GRANITICS:
@ 1'/2' Disintegrates to SILTY SAND, dark reddish brown, moist, medium 5 dense.
@ 3'As per 1'/2; reddish brown.
5'As per 3'; light reddish brown.

Total Depth = 6'
No Groundwater or Caving Encountered
Backfilled 2-16-21
10 15
20 25
30 0 Standard Penetration Test = Groundwater T Undisturbed, Ring Sample 2 Seepage
GeoSoils, Inc.

PLATE B-4

GeoSoils, Inc. BORING LOG
PROJECT: DJORDJEVICH
1205 Melrose Way W.O. 8058-A-SC BORING HA-4 SHEET 1 OF 1 DATE EXCAVATED 2-16-21 LOGGED BY: MS APPROX.ELEV.: 358'MSL SAMPLE METHOD: Hand Auger
Sample
U
0 o Material Description
T O
j LL U) "' 2 0
L U N U) 2
n Y 3 L) m
0 o co coD 0 co
0 CH COLLUVIUM:
@ 0' SANDY CLAY, dark brown to dark reddish brown, moist, soft to medium stiff; fine to medium grain sand.

CL WEATHERED GRANITICS:

Sc @ 2'/2' Disintegrates to SANDY CLAY, reddish brown to light reddish brown, dry to damp, stiff; feisic rock fragments.
5 @ T CLAYEY SAND, pale yellow to very light reddish brown, dry to damp, dense.

Total Depth =4', Terminated Due to Time Constraint
No Groundwater or Caving Encountered
Backfilled 2-16-21
10 15
20 25
30 0 Standard Penetration Test = Groundwater T Undisturbed, Ring Sample 2 Seepage
GeoSoils, Inc.

PLATE B-5

APPENDIX C

SEISMICITY DATA
GeoSoils, Inc.

� E0FAULT �
� Version 3.00 �

DETERMINISTIC ESTIMATION OF

PEAK ACCELERATION FROM DIGITIZED FAULTS
J08 NUMBER: 8058
DATE: 02-I6-202I
JOB NAME: Zoran D 'nrd 'evich
CALCULATION NAME: Test Run Analysis
FAULT-DATA-FILE NAME, [:\Prngram Files\EQFAULTl\[GSFLTE.DAT SITE COORDINATES:

SITE LATITUDE: 33.I854
SITE LONGITUDE: 117.2569
SEARCH RADIUS: 62.4 mi
ATTENUATION RELATION: 12) 8ozorgnia Campbell Niazi (1999) Hor.-Soft Kock-[or.

UNCERTAINTY {M~Median, S=Sigma} : S Number of Sigmas: 1.0 DISTANCE MEASURE: cdist
S[OND: O
Basement Depth: .10 km Campbell 55R: l Campbell SHK: U

COMPUTE PEAK HORIZONTAL ACCELERATION
FAULT-DATA FILE USED: [:\Prngram Files\EQFAULTl\[GSFLTE.DAT MINIMUM DEPTH VALUE (km) : 3.0
Page l
VV.O. 8058-A-GC
PLATEC'1

---------------

EQFAULT SUMMARY
---------------
-----------------------------

DETERMINISTIC SITE PARAMETERS
-----------------------------