Attachment E - Applicant's Project Description and Supporting Documents

908 Industrial Ave, Palo Alto CA 94303 | (833) 262-2208 | [email protected] | www.spacial.io Page | 1
Letter of Application
Date: 01.30.2026
Dear Planning StaƯ,
This letter is submitted in support of our proposed residential project located within the OS (Open Space) zoning district of the City of Palo Alto. The project consists of a single-family residence designed to preserve the site’s natural hillside character, minimize environmental disturbance, and integrate with the surrounding landscape. Below is a summary demonstrating the project’s consistency with the Palo Alto Comprehensive Plan and the Open Space Development Criteria adopted on October 20, 1986.

1. Consistency with the Palo Alto Comprehensive Plan
The proposed development is consistent with the following goals and policies from the Comprehensive Plan:
 Land Use Policy L-6.4 (Protection of Open Space Areas):

The project is sited and designed to preserve the open hillside setting. In conjunction with the City Arborist and the Fire Marshall, 15 trees (14 protected and 1 unprotected) have been designated as eligible for removal for the building and for thinning cluster trees within 30’ of the building, and the structure is positioned to work with the existing slope to minimize grading and maximize views.
 Natural Environment Policy N-1.2 (Environmental Stewardship):

Native, ﬁre resistant and drought-tolerant landscaping is incorporated to enhance ecological health and reduce water consumption. 60 new replacement trees are proposed in compliance with the Palo Alto tree technical manual. Replacement tree species include Coastal Live Oak, Blue Oak and Valley Oak, all native to the local environment.  Design & Built Environment Goal L-6 (Context-Sensitive Design):

The home maintains a low proﬁle from the public right-of-way, uses earth-toned materials, and is stepped with the slope, blending with the natural terrain.

ATTACHMENT E

908 Industrial Ave, Palo Alto CA 94303 | (833) 262-2208 | [email protected] | www.spacial.io Page | 2

 Mobility Goal T-5 (Minimizing Impacts):

The driveway utilizes permeable concrete to reduce runoƯ, and parking is accommodated entirely on-site with no additional demand on local streets.

2. Compliance with the 10 Open Space Development Criteria

1. Preservation of Natural Character:

The design minimizes grading by following the natural slope. The lower level is terraced to preserve topography, and mature trees are preserved. Minimal grading outside of the building envelope has been proposed to maintain the natural contours of the site.

2. Views and Vistas:

The structure is sited downslope from the street, protecting public view corridors. Upper decks and glazing maximize private enjoyment of views without creating massing impacts from public vantage points. Story poles have been installed on the site to verify and ensure that the building will not disturb the views and vistas of the public and the neighbors.

3. Environmental Quality:

Permeable surfaces, drought-resistant planting, and rooftop solar panels are included.

Erosion control measures will be implemented during construction in order to prevent any contamination.

4. Use Compatibility:

The proposed single-family residential use is consistent with the passive, low-density intent of the OS zone.

908 Industrial Ave, Palo Alto CA 94303 | (833) 262-2208 | [email protected] | www.spacial.io Page | 3

5. Access and Circulation:

Site access is via a single, existing driveway. Circulation is limited and unobtrusive. The permeable concrete driveway provides both function and environmental beneﬁt.

6. Facility Design:

The architecture is modern and modest in scale, with low pitched roofs and earth-tone materials that recede visually into the landscape.

7. Vegetation and Landscaping:

Landscaping uses ﬁre resistant, native species to preserve habitat value and minimize maintenance. No invasive species are proposed. 60 new replacement trees are proposed, in compliance with the Palo Alto tree technical manual. Replacement tree species include Coastal Live Oak, Blue Oak and Valley Oak, all native to the local environment.

8. Public Beneﬁt:

While this is a private residence, the design preserves the open character of the land, enhances natural resource protection, and avoids adverse public impacts.

9. Maintenance and Management:

As a private residence, all maintenance is the responsibility of the homeowner. Long-term landscape and site maintenance will ensure continued preservation of site character.

10. Mitigation:

All development impacts have been minimized through sensitive design and site planning. A construction management plan will mitigate temporary construction eƯects.

908 Industrial Ave, Palo Alto CA 94303 | (833) 262-2208 | [email protected] | www.spacial.io Page | 4

Conclusion
We believe this project aligns with the vision of the Palo Alto Comprehensive Plan and fulﬁlls all requirements under the OS Development Criteria. The proposed design is a sensitive, sustainable addition to Palo Alto’s open space community fabric and reﬂects a strong commitment to environmental stewardship and contextual design.

Thank you for your consideration.

Sincerely,
Daniel Hruby, Architect

11/20/2024
Licensed Arborist - W. M. Smith
WE-13625A
Moki Smith Arborist
[email protected]
408-722-8942

Arborist Report
Site Address - Laurel Canyon Drive, Palo Alto 94304
Site Visit - November 12th, 2024

Licensed arborist William Smith visited the property located at Laurel Canyon Drive, Palo Alto 94304, in order to identify and assess all trees that are presently located on the subject property or on the adjacent properties that could be affected by development on the subject property.

The trees included in this tree inventory are coast live oak (Quercus agrifolia), blue oak (Quercus douglasii), Bay laurel (Laurus nobilis) and Valley oak (Quercus lobata). Within this report you will find key data pertaining to each individual tree, their conditions, and locations.

Respectfully Submitted,
William Smith

Table of Contents
Introduction ————————————————————————Page 1
Report Contents and Location—————————————————Page 3
Tree Structure and Condition Definitions—————————————Page 4 Suitability for Preservation——————————————————-Page 6
Protected Tree Ordinance ———————————————————Page 7
Tree Inventory——————————————————————-—Page 12
Assessment and Observations—————————————————Page 16
Site Map——————— ——————————————————-Page 22
Tree Protection Measures ——————————————————-Page 23
Tree Protection Fencing———————————————————-Page 24
Tree Replacement Plan————————————————————Page 25
Report Contents:

1.Tree Survey Data:
◦ Tag numbers, species, trunk diameters (DBH), approximate tree heights, approximate canopy spreads, and overall conditions.
◦ Visual assessment and specific observations to highlight specific tree health and structural issues.

2.Protected Tree Analysis:
◦ Analysis to determine the number of trees that are considered protected. ◦ Assessment of trees protected under San Jose’s Tree Ordinance.

3.Tree Protection Plan:
◦ Outline of preservation measures for trees that will remain on-site during development.
◦ Assessment of development impacts on the trees that are protected under San Jose’s Tree Ordinance
Project Location:

The project site consists of the parcel of land located north of Laurel Glen Drive. This property is considered an oak woodland, as it is dominated by native oak species such as Coast Live Oak (Quercus agrifolia), Valley Oak (Quercus lobata), and Blue Oak (Quercus douglasii).

Survey Methods:

The tree survey and inventory were conducted by ISA certified arborist W. M. Smith (Certification #WE-13625A), with a focus on assessing all trees with a single main stem diameter at breast height (DBH) of 5 inches or more, or co-dominant stems with a combined DBH of at least 6 inches. This survey included all trees located on the specified parcel, within 100 feet of the proposed development. It was determined that none of the trees in this survey are classified as heritage trees under the City of Palo Alto’s guidelines, nor are they considered orchard trees cultivated for commercial purposes.

This assessment provides a comprehensive overview of each tree’s current health, structural condition, and potential impact within the context of the proposed site development.

The following data was collected for each tree:
•Trunk Diameter: Measured at 54 inches above grade (DBH). •Tree Species: Identified based on observed characteristics. •Tree Height: Approximate measurements taken visually.
•Canopy Spread: Approximate measurements taken visually. •General Condition: Based on a visual assessment - no coring, lab testing, or aerial inspection were employed.

Tree Condition and Structure:

A visual assessment of health and structure were used to assign a general condition rating for each tree. The evaluation of the trees surveyed in this report was limited to a visual inspection of accessible parts without dissection, excavation, probing, or coring. There is no guarantee that additional problems or defects in the trees may not arise in the future.

Refer to the following scale for general condition:

Good: 75%-100% healthy foliage, free of major defects, good form and function for the location.

Fair: 35-75% healthy foliage, moderate defects that may compromise the function or form of the tree overtime if left un-treated.

Poor: Less than 35% of healthy foliage and significant defects resulting in a low life expectancy.

This assessment includes 63 trees, with the majority rated in Fair condition due to both health and structural challenges from lack of proper maintenance. Trees in this category generally exhibit some vigor in foliage and growth, though they have minor to moderate defects that impact their structural stability and long term health, such as co-dominant stems, moderate leans, the presence of included bark, or decay cavities. These moderate defects contribute to a reduced suitability for preservation under current site conditions. A smaller subset of trees has been classified in Poor condition, showing significant decline in health and structural integrity, often due to past damage, disease, or inadequate previous maintenance. Only a few trees have received a Good condition rating, distinguished by healthy, dense foliage and an absence of significant structural or health defects. These trees represent the best preservation candidates, as they are expected to continue thriving with minimal intervention. The findings suggest that, while a number of trees contribute positively to the site, the majority will require management or removal due to their compromised condition.

Tree Structure:

Good: Minor structural flaws that may be corrected through pruning. Tree has an upright trunk and a single trunk tapering to a single leader at the top. Most scaffold branches are smaller than the leader, attached to the trunk at angles approaching 45 degrees and are spaced apart on the trunk both vertically and radially. Structure does not contain included bark {bark inside the juncture of multiple trunks). No sign of previous branch failures.

Foliage is evenly distributed on the limbs. Symmetrical or mostly symmetrical canopy.

Fair: Some structural flaws not correctable through pruning. Tree may have more than one trunk or leader, trunk may have a slight lean. Scaffold branches may be attached at angles less than 30 degrees and/or may be crowded on the trunk. Structure may have included bark, previous branch failures or end-heavy limbs. Some asymmetry in the canopy.

Poor: Significant structural flaws not correctable through pruning. Significant dead wood or decay. More than one trunk or leader and/or branches crowded together on the trunk.

Significantly end-heavy limbs may be present. Structure may contain significant included bark, previous branch failures and/or asymmetry. Precipitous lean may be present. Tree is likely to be hazardous.

Inventory Results:

Moki Smith Arborist surveyed a total of 63 trees across the parcels that are included in the proposed development project. This tree inventory includes all of the significant trees that are located within 100 feet of the proposed development. All of the trees present within the parameters of this survey are considered indigenous species. The indigenous species includes forty blue oaks (Quercus douglasii), eighteen coast live oaks (Quercus agrifolia), and four valley oaks (Quercus lobata). Protected trees are noted in the inventory tree table. There are no fruit or orchard trees located on the parcel, and none of these trees are used for commercial purposes. Of the trees included in this report 55 are considered protected under Palo Alto City Ordinance. There are no invasive or non- indigenous trees located on the property within the parameters included in this report.

Suitability for Preservation:

In assessing the trees’ suitability for preservation, several factors were considered:

1.Health: Healthy trees are better equipped to tolerate development impacts, such as soil compaction and changes in moisture.

2.Structural Integrity: Trees with significant decay or structural defects increase the likelihood of failure, which can increase the possibility that the tree poses a threat or hazard, particularly in areas near people or property.

3.Species Response: Certain species, such as those accustomed to the native environment, are more tolerant of development impacts than non-native species which may require different environmental conditions to prosper ( such as increased irrigation).

4.Age and Longevity: Older trees may be less adaptable to development impacts and root damage/loss, while younger trees have greater capacity for regeneration and adjustment.

The suitability for preserving the 63 trees located on this development site in Palo Alto varies due to several factors. While 55 of these trees are considered protected, many of the trees have less preservation value due to structural and health issues. These defects include multiple co-dominant stems that emerge from low or below-ground main crotches, and the presence of included bark, which increases structural risk as the trees mature. This is compounded by poor structure, with many trees leaning toward light sources, which predisposes them to failure under extreme weather conditions such as high winds or heavy rainfall.

Additionally, several of the oaks exhibit moderate decay on their main stems, a result of unaddressed damage from lost major limbs or fungal diseases infecting tissue of the main stem.

To ensure the longevity and structural integrity of the oak trees slated for preservation, targeted pruning should be undertaken. This includes the removal of large deadwood to minimize potential hazards and promote tree health. Structural pruning is recommended to enhance canopy balance, reduce stress on weak or vulnerable branches, and lower the risk of structural failure, particularly under adverse weather conditions. These efforts not only improve safety but also support the tree's ability to thrive in the landscape while

maintaining its ecological and aesthetic value. Proper pruning should adhere to ANSI A300 standards to minimize damage and promote optimal healing of pruning wounds.

Some of the oak trees on the site exhibit signs of fungal diseases affecting their foliage and stems, which could pose a risk to their overall health if not addressed. To mitigate the spread of these fungal pathogens, a proactive treatment plan is recommended, including the application of appropriate fungicides as determined by further diagnostic analysis.

Additionally, these trees should be fertilized to optimize soil health and enhance the trees' vigor, increasing their natural resistance to infections and diseases. Improving cultural practices such as proper irrigation and mulch application can further reduce stress on the trees and support their recovery. These measures should be implemented under the guidance of a certified arborist to ensure their effectiveness and adherence to best practices.

The majority of the trees located on the subject property are native Coast live oaks (Quercus agrifolia), Blue oaks (Quercus Douglasii), and Valley oaks (Quercus lobata) which show a high potential for successful preservation, due to their native status and natural adaptation to local conditions. These trees are likely to thrive long-term on this site if proper maintenance and cultural care are preformed.

Protected Trees:

Palo Alto Tree Ordinance

8.10.010 Purpose.

The purpose of this chapter is to protect specified trees located on private property within the city, and establish standards for removal, maintenance, and planting of trees and landscaping. In establishing these procedures and standards, the city recognizes that trees and landscaping are an essential part of the city's infrastructure. Their benefits include promoting the health, safety, welfare, and quality of life of the residents of the city; addressing climate change by sequestering carbon and providing a cooling effect; reducing air, water, and noise pollution; preventing soil erosion and stormwater runoff; providing wildlife habitat; and enhancing the aesthetic environment.

It is the city's intent to encourage both the preservation of trees and the proactive incorporation of trees and their benefits within development.
“Protected” tree includes the three species that were already protected as well as additional native tree species and all trees above specified minimum diameters, except high water users and invasive species. [§8.10.020(l)]

8.10.050 Removal of protected trees.

It shall be a violation of this chapter for anyone to remove or cause to be removed a protected tree, except pursuant to a protected tree removal permit issued under Section 8.10.140 consistent with the following:
(a)In the absence of proposed development:
(1)A protected tree shall not be removed unless the urban forester grants a protected tree removal permit, or on parcels zoned other than single-family (R-1) or low density residential (RE, R-2, or RMD), the director of planning and development services authorizes the removal through staff level architectural review pursuant to Section 18.76.020(b)(3), having determined, on the basis of a tree report prepared by a designated arborist and other relevant information, that treatments or corrective practices are not feasible, and that the tree should be removed because any of the following apply:
(i)It is dead, is hazardous, or constitutes a public nuisance under Section 8.04.050 of this code. (ii)It is a detriment to or is crowding an adjacent protected tree. (iii)It is at risk for retrenchment or other tree decline coping processes or does not conform with right tree in the right place principles.
(iv)It is impacting the foundation or eaves of a residence, or any covered parking required under Title 18 of this code.
(2)In the event a protected tree is removed pursuant to a protected tree removal permit granted under this subsection (a), a temporary moratorium on development of the subject property may be issued by the urban forester for up to twenty-four months or by, the director of planning and development services, in consultation with the urban forester, for up to thirty-six months, from the date the tree removal occurred. Completion of required mitigation measures included in the tree removal permit does not remove or shorten any such moratorium. A moratorium may be terminated early with approval of the urban forester or director of planning, and development services, as applicable, and may require additional mitigation measures. Mitigation measures included in the protected tree removal permit and any additional mitigation measures required to shorten a moratorium shall be imposed as a condition of any subsequent permits for development on the subject property.

Species Updat
ed
Ordin
an ce
Previ
ou s
Ordin
an ce
Coast live oak 11.5 inches 11.5 inches
Valley oak 11.5 inches 11.5 inches
Coast redwood 18 inches 18 inches
Bigleaf maple 11.5 inches
Blue oak 11.5 inches
California black oak 11.5 inches
California incense cedar 11.5 inches
Others except invasive species
and high water users
15 inches
(b)In the case of any development on a single-family (R-1) or low density (RE, R-2, or RMD) residential zoned parcel, other than in connection with a subdivision, a protected tree shall not be removed unless the tree is proposed for removal to accommodate an ADU constructed pursuant to Section 18.09.030, or because removal is necessary to allow an ADU constructed pursuant to Section 18.09.040 to achieve the minimum standards set forth in state law, or it is determined by the urban forester, on the basis of a tree report prepared by a designated arborist and other relevant information, that any of the following apply:
(1)The tree is so close to the proposed development that construction would result in the death of the tree, and there is no financially feasible design alternative that would permit preservation of the tree, where financially feasible means an alternative that preserves the tree unless retaining the tree would increase project cost by more than twice the reproduction cost of the tree or ten percent of the given project valuation, whichever is greater. (2)Retention of one or more trees would result in reduction of the otherwise-permissible buildable area of the lot by more than twenty-five percent, and there is no financially feasible design alternative that would allow for preservation of the tree(s). For the purposes of this subsection (a)(2), a financially feasible design alternative means a design alternative that preserves the tree(s) and would not increase the project cost by more than twice the reproduction cost of the tree(s) or ten percent of the given project valuation, whichever is greater. All tree protection zones impacting buildable area are included in the reduction of buildable area calculation. (3)The tree could be removed due to the conditions listed in Section 8.10.050(a)(1)(i), (ii), or (iii) and treatments or corrective practices are not feasible.
(c)In the case of development involving a proposed subdivision of land into two or more parcels, a protected tree shall not be removed unless determined by the urban forester, on the basis of a tree report prepared by a designated arborist and other relevant information, that either of the following apply:
(1)Removal is unavoidable due to restricted access to the property or deemed necessary to repair a geologic hazard (landslide, repairs, etc.), in which case only the protected tree or trees necessary to allow access to the property or repair the geologic hazard may be removed.
(2)The tree could be removed due to the conditions listed in subsection (a)(1)(i), (ii), or (iii) and treatments or corrective practices are not feasible.
(d)In the case of development requiring planning approval under Title 18, and not included under subsections (b) or (c), a protected tree shall not be removed unless determined by the urban forester, on the basis of a tree report prepared by a designated arborist and other relevant information, that any of the following apply:
(1)Retention of one or more trees would result in reduction of the otherwise-permissible buildable area of the lot by more than twenty-five percent, and there is no financially feasible design alternative that would permit preservation of the tree(s), where financially feasible means an alternative that preserves the tree(s) unless retaining the tree(s) would increase project cost by more than twice the reproduction cost of the tree or ten percent of the given project valuation, whichever is greater. All tree protection zones impacting buildable area are included in the reduction of buildable area calculation.
(2)The tree should be removed because it is dead, hazardous, or constitutes a public nuisance under Section 8.04.050. In such cases, the tree protection zone of the removed tree, or an equivalent area on the site, shall be preserved for mitigation purposes from development of any structure. (3)Discretionary development review determines that the final project follows right tree in the right place principles and would result in a net tree canopy increase on the property within fifteen years, and replacement of trees, shrubs, and plants either:
(i)Is consistent with Urban Forest Master Plan Goal 2: "Re-generated native woodland and riparian landscapes as the key ecological basis of the urban forest with focus on native species and habitat," or (ii)Uses climate adaptive, drought tolerant species.
(e)In any circumstance other than those described in subsections (a), (b), (c), or (d), a protected tree shall not be removed unless determined by the urban forester, on the basis of a tree report prepared by a designated arborist and other relevant information, that the tree is dead, is hazardous, or constitutes a public nuisance under Section 8.04.050.

8.10.055 Tree replacement.
(a)In the event a protected tree is removed pursuant to Section 8.10.050(a)(1)(i), mitigation for the removed tree, replacement tree ratio, in lieu fees, or a combination thereof shall be determined by the urban forester, based on factors including but not limited to the species, size, location, and specific reason for removal of the protected tree, in accordance with the standards and specifications in the Tree and Landscape Technical Manual. (b)In the event a protected tree is removed pursuant to Section 8.10.050 (a)(1)(ii), (iii), or (iv), (b), (c), (d), or (e), the tree removed shall be replaced in accordance with the standards and specifications in the Tree and Landscape Technical Manual, including but not limited to prioritization of locally native species, satisfaction of right tree in the right place principles, and incorporation of a secondary goal of net tree canopy increase on the property within fifteen years. The urban forester shall approve the number, species, size, and location of replacement trees.

Indigenous species:

The following trees are considered indigenous:

Coast live oak, Valley oak, Coast redwood, Big leaf maple, Blue oak, California black oak, California incense cedar, and Blue oak.

Potential Impacts:

The proposed development will necessitate the removal of several oak trees located directly within the construction footprint to accommodate the property structures. For the trees designated for retention, it is critical to implement protective measures to minimize construction-related impacts. Tree protective fencing must be installed around the drip- line of each retained tree to safeguard the main stems, canopies, and critical root zones from damage caused by heavy machinery and soil compaction. The fencing should be robust, highly visible, and remain in place for the duration of the project. Additionally, a detailed tree protection plan, including guidelines for permitted activities within the protected zones and measures for addressing inadvertent damage, is provided at the end of this report. Adherence to these measures is essential to ensure the health and preservation of the retained trees
Prepared by:

W. M. Smith (ISA Certified Arborist #WE 13625A)
Moki Smith Arborist
408-722-8942
[email protected]
Tree Inventory Table
Tree
Tag
ID
Common Name Species D.B.H. Hei
gh t
Cro
wn
Spr
e ad
Condit
io n
Protecte
d
1 Blue Oak Quercus
douglasii
19 38 30 Fair Yes
2 Blue Oak Quercus
douglasii
17 40 30 Fair Yes
3 Coast Live Oak Querc
us
agrifol
ia
19/17/1
6 40 40 Fair Yes
4 Blue Oak Quercus
douglasii
15 45 20 Fair Yes
5 Coast Live Oak Querc
us
agrifol
ia
13/15 38 30 Good Yes
6 Blue Oak Quercus
douglasii
24 45 40 Fair Yes
7 Blue Oak Quercus
douglasii
15/11/1
1 40 50 Fair Yes
8 Coast Live Oak Querc
us
agrifol
ia
19 40 30 Poor Yes
9 Coast Live Oak Querc
us
agrifol
ia
24 50 35 Fair Yes
10 Valley Oak Querc
us
lobata
11 25 20 Fair No
11 Blue Oak Quercus
douglasii
21 55 30 Poor Yes
12 Coast Live Oak Querc
us
agrifol
ia
29/23 25 30 Poor Yes
13 Coast Live Oak Querc
us
agrifol
ia
14/11 30 25 Fair Yes
14 Coast Live Oak Querc
us
agrifol
ia
7 25 15 Fair No
15 Coast Live Oak Querc
us
agrifol
ia
22 45 35 Fair Yes
16 Coast Live Oak Querc
us
agrifol
ia
18 45 30 Fair Yes
17 Coast Live Oak Querc
us
agrifol
ia
24 45 40 Good Yes
18 Coast Live Oak Querc
us
agrifol
ia
8/18/17 50 50 Fair Yes
19 Coast Live Oak Querc
us
agrifol
ia
7/20/9 40 45 Fair Yes
20 Coast Live Oak Querc
us
agrifol
ia
17 25 20 Fair Yes
21 Coast Live Oak Querc
us
agrifol
ia
14 35 25 Fair Yes
22 Blue Oak Quercus
douglasii
16 30 30 Fair Yes
23 Blue Oak Quercus
douglasii
14 35 25 Fair Yes
24 Blue Oak Quercus
douglasii
22 40 35 Fair Yes
25 Valley Oak Querc
us
lobata
10/13 35 35 Fair Yes
26 Coast Live Oak Querc
us
agrifol
ia
14 30 35 Fair Yes
27 Coast Live Oak Querc
us
agrifol
ia
11/15/1
4 / 12
35 50 Fair Yes
28 Blue Oak Quercus
douglasii
21 45 40 Fair Yes
29 Blue Oak Quercus
douglasii
17 40 35 Fair Yes
30 Blue Oak Quercus
douglasii
20 45 30 Fair Yes
31 Blue Oak Quercus
douglasii
11/14 40 35 Fair Yes
32 Bay Laurel Lau
r us
nob
il is
7 15 10 Fair No
33 Blue Oak Quercus
douglasii
14 35 25 Poor Yes
34 Blue Oak Quercus
douglasii
14 40 30 Poor Yes
35 Blue Oak Quercus
douglasii
15 40 30 Fair Yes
36 Blue Oak Quercus
douglasii
18 40 30 Fair Yes
37 Valley Oak Querc
us
lobata
28 55 50 Fair Yes
38 Blue Oak Quercus
douglasii
14 35 35 Fair Yes
39 Blue Oak Quercus
douglasii
17 40 30 Fair Yes
40 Blue Oak Quercus
douglasii
15 40 40 Fair Yes
41 Blue Oak Quercus
douglasii
18 45 35 Fair Yes
42 Blue Oak Quercus
douglasii
9 20 15 Fair No
43 Blue Oak Quercus
douglasii
11/10 40 40 Fair Yes
44 Blue Oak Quercus
douglasii
9 30 22 Fair No
45 Blue Oak Quercus
douglasii
15 40 30 Fair Yes
46 Blue Oak Quercus
douglasii
20 38 30 Fair Yes
47 Blue Oak Quercus
douglasii
13 35 25 Fair Yes
48 Blue Oak Quercus
douglasii
11 50 25 Fair No
49 Blue Oak Quercus
douglasii
6 30 18 Fair No
50 Blue Oak Quercus
douglasii
15 40 35 Fair Yes
51 Blue Oak Quercus
douglasii
13 40 35 Fair Yes
52 Coast Live Oak Querc
us
agrifol
ia
21 45 35 Fair Yes
53 Blue Oak Quercus
douglasii
11 25 20 Fair No
54 Blue Oak Quercus
douglasii
23 40 35 Fair Yes
55 Blue Oak Quercus
douglasii
25 45 40 Fair Yes
56 Valley Oak Querc
us
lobata
15/13 40 45 Fair Yes
57 Blue Oak Quercus
douglasii
14 35 30 Fair Yes
58 Blue Oak Quercus
douglasii
16 35 30 Fair Yes
59 Blue Oak Quercus
douglasii
14 40 20 Fair Yes
60 Blue Oak Quercus
douglasii
19 40 35 Fair Yes
61 Blue Oak Quercus
douglasii
14 40 40 Fair Yes
62 Blue Oak Quercus
douglasii
11 35 25 Fair No
63 Coast Live Oak Querc
us
agrifol
ia
21 45 40 Good Yes
Assessment and Observations
Tree Tag# 1
This tree has a moderate lean in the southern direction due to competition for light. Mistletoe noted in the canopy.

Tree Tag# 2
This tree has a significant lean in the southern direction due to competition for light with neighboring oak trees. Minor die back noted in the canopy.

Tree Tag# 3
This tree has a significant lean in the southern direction due to competition for light with neighboring oak trees. Minor die back noted in the canopy.

Tree Tag# 4
Minor fungal damage noted on the foliage of this tree. This tree has a moderate south eastern lean due to competition for light with neighboring trees. Minor die back noted in the canopy.

Tree Tag# 5
This tree has two co-dominant uprights emerging from the first main crotch located approximately 24 inches above grade.

Tree Tag# 6
This tree has a slight southern lean due to competition for light with neighboring oak trees. Decay cavity noted on one co-dominant upright emerging from approximately 6 feet above grade up to approximately 10 feet above grade.

Tree Tag# 7
Fungal damage noted on the foliage of this tree. Moderate die back noted in the upper canopy. This tree has three co-dominant uprights emerging from a subterranean first main crotch.

Tree Tag# 8
This tree has evidence of a boring winged beetle noted on the southern side of the main stem frass located in the decay under the bark tissue. Decay cavity noted on the main stem emerging from approximately 10 inches above grade up to approximately 38 inches above grade.

Tree Tag# 9
This tree has two co-dominant uprights emerging from a first main crotch located approximately 40 inches above grade. Major cracking noted on the easternmost upright. This tree lost a third co-dominant upright on the western side of the tree, and a fourth co-dominant lateral upright on the western side of the tree
Tree Tag# 10
This tree has a significant western lean at approximately 20 feet above grade. Cavity noted on the southern side of the main stem approximately 8 feet above grade.

Tree Tag# 11
This tree has a south eastern lean. Fungal damage noted on the foliage. Moderate/significant die back noted in the canopy.

Tree Tag# 12
This tree has two co-dominant uprights emerging from a subterranean first main crotch. One of the uprights has a significant southern lean. The northernmost upright has been removed to approximately 12 feet above grade, epicormic growth is comprising the canopy of this upright. This tree has recently lost a major co-dominant upright, resulting in the loss of significant structural tissue.

Tree #12 is located on the adjacent property approximately 10 feet from the property boundary line.

Tree Tag# 13
This tree has two co-dominant uprights emerging from a first main crotch located approximately 6 inches above grade. One co-dominant upright has a significant southern lean. The second co-dominant upright has a significant western lean. Minor fungal damage on the foliage.

Tree Tag# 14
This tree has a significant southern lean.

Tree Tag# 15
This tree has a moderate southern lean noted, due to competition for light with neighboring oaks.

Significant 10 inch lateral limb has been removed on the main stem years ago at approximately 6 feet above grade.

Tree Tag# 16
This tree has a significant southern lean due to competition for light with neighboring trees Tree Tag# 17
This tree has a slight southern lean on the main stem due to competition for light.

Tree Tag# 18
This tree has two large co-dominant uprights emerging from the first main crotch located approximately 24 inches above grade. Included bark noted between the uprights. Northernmost upright has a significant northern lean. Minor die back noted in the canopy.

Tree Tag# 19
This tree has two large co-dominant uprights emerging from the first main crotch located approximately 24 inches above grade. Included bark noted between the uprights. Northernmost upright has a significant northern lean. Minor die back noted in the canopy.

Tree Tag# 20
This tree has a significant northern lean due to competition for light with neighboring oak trees.

Tree Tag# 21
Evidence of boring insect, entrance wounds on the southern side of the main stem up to approximately 10 feet above grade.

Tree Tag# 22
This tree has a very significant western lean.

Tree Tag# 23
This tree has the majority of its canopy comprised on the western side of the tree. Fungal fruiting bodies noted on the northern side of the main stem. Decay cavity present on the main stem at the root flare on the northern side of the tree.

Tree Tag# 24
This tree has moderate die back noted in the canopy. Minor fungal damage noted in the canopy. Multiple large lateral limbs have failed due to fungal disease. Fungal fruiting bodies noted on the canopy branches.

Tree Tag# 25
This tree has two co-dominant uprights emerging from a subterranean first main crotch, included bark noted between co dominant stems. Minor die noted in the upper canopy.

Tree Tag# 26
This tree has a minor northern lean due to competition for light with neighboring oak tree. Fungal damage noted on the foliage of this tree. Minor die back noted in the canopy of this tree.

Tree Tag# 27
This tree has multiple co-dominant uprights emerging from a first main crotch located approximately 6 inches above grade. One upright is emerging in the western direction, one in the northern direction, and two in the eastern direction.

Tree Tag# 28
This tree has moderate die back noted in the upper canopy. Multiple dead lateral limbs noted.

Tree Tag# 29
This tree has moderate die back noted in the canopy. Fungal disease noted on the foliage of this tree.

Tree Tag# 30
This tree has lost multiple limbs in the canopy due to fungal disease. Moderate die back noted in the canopy. Fungal damage noted on the foliage of the tree.

Tree Tag# 31
This tree has two co-dominant uprights emerging from the first main crotch located approximately 24 inches above grade. Fungal damage noted on the foliage of this tree. Moderate die back noted in the canopy.

Tree Tag# 32
This tree has multiple decay wounds on the main stem majority of the canopies, comprise the secondary growth
Tree Tag# 33
This tree has a moderate southern lean due to competition for light with neighboring oak trees. Galls noted on the stems of the canopy. Fungal damage noted on the foliage.

Tree Tag# 34
This tree has a slight southern lean. Fungal damage noted on the foliage of this tree. Minor decay cavities noted on the main stem due to loss of limbs.

Tree Tag# 35
This tree has a slight southern lean due to competition for light with neighboring oaks. Fungal damage noted on the foliage of this tree. Moderate die back noted in the canopy of this tree.

Tree Tag# 36
This tree has moderate die back noted in the upper canopy. Canopy has a slight southwestern lean.

Tree Tag# 37
This tree has two co-dominant uprights emerging from the first main crotch located approximately 8 feet above grade, included bark noted between these uprights. Fungal damage noted on the foliage of this tree.

Moderate die back noted in the upper canopy.

Tree Tag# 38
This tree has a moderate north-eastern lean. Moderate die back noted in the canopy. Fungal damage noted on the foliage.

Tree Tag# 39
The canopy of this tree has a slight southern lean due to competition for light. Fungal damage noted on the foliage. Moderate die back noted in the canopy.

Tree Tag# 40
Canopy of this tree has a slight western lean. Fungal damage noted on the foliage. Moderate die back noted in the canopy.

Tree Tag# 41
This tree has a moderate south eastern lean. Fungal damage noted on the foliage of this tree. Moderate die back in the canopy.

Tree Tag# 42
This tree has a moderate northern lean on the main stem. Fungal damage noted on the foliage. Minor die back in the canopy.

Tree Tag# 43
This tree has two co-dominant uprights emerging from the first main crotch located approximately 40 inches above grade. Moderate die back noted in the canopy.

Tree Tag# 44
This tree extends in the eastern direction at approximately 15 feet above grade due to competition for light with neighboring oak tree. Moderate die back in the canopy.

Tree Tag# 45
This tree has fungal damage noted on the foliage. This tree has lost multiple lateral limbs. Moderate die back in the canopy.

Tree Tag# 46
This tree has a moderate southern lean. Two co-dominant upright emerged from the first main crotch located approximately 6 feet above grade. Moderate die back noted in the canopy.

Tree Tag# 47
This tree has a moderate eastern lean due to competition for light with neighboring oak trees. This tree has two co-dominant uprights, emerging from the first main crotch located approximately 7 feet above grade. Minor die back noted in the canopy.

Tree Tag# 48
This tree has a minor eastern lean. Fungal damage noted on the foliage. Moderate die back in the canopy.

Tree Tag# 49
Fungal damage noted on the foliage of this tree. Minor die back noted in the canopy.

Tree Tag# 50
This tree has a minor southern lean. Fungal damage noted on the foliage. Moderate die back noted in the canopy.

Tree Tag# 51
This tree has a minor southern lean due to competition for light. Fungal damage noted on the foliage.

Moderate die back noted in the canopy.

Tree Tag# 52
This tree has a moderate southern lean. Minor die back noted in the canopy.

Tree Tag# 53
Moderate die back noted in the canopy of the tree. Fungal damage noted on the foliage of this tree.

Tree Tag# 54
This tree has a minor south eastern lean. Moderate die back noted in the canopy.

Tree Tag# 55
Minor die back noted in the canopy of this tree. Fungal damage noted on the foliage.

Tree Tag# 56
This tree has two co-dominant uprights emerging from a first main crotch located approximately 18 inches above grade. One co-dominant upright has a significant northwestern lean. Moderate die back noted in the canopy of this tree.

Tree Tag# 57
This tree has minor fungal damage noted on the foliage. Minor die back noted in the canopy. Minor decay wound on the base of the main stem on the northern side.

Tree Tag# 58
This tree has a minor south eastern lean on the main stem. Decay wound noted on the main stem on the northern side of the canopy. At approximately 45 inches above grade.

Tree Tag# 59
This tree has fungal damage noted on the foliage and minor die back in the canopy.

Tree Tag# 60
This tree has a decay cavity noted on the main stem of approximately 6 feet above grade up to approximately 10 feet above grade. Minor fungal damage noted on the foliage.

Tree Tag# 61
This tree has two co-dominant uprights emerging from the first main crotch located approximately 11 feet above grade. Canopy has a north eastern lean. Fungal damage noted on the foliage. Minor die back noted in the canopy.

Tree Tag# 62
This tree has a minor eastern lean. Fungal damage noted on the foliage of this tree. Minor die back noted in the canopy.

Tree Tag# 63
This tree has a minor northern lean.

Site Map

Tree Protection Measures for construction
•Avoid root damage through grading, trenching, compaction, etc., at least within an area 1.5 times the ‘drip-line’ area of trees. Where root damage cannot be avoided, roots encountered (over 1" diameter) should be exposed approximately 12" beyond the area to be disturbed (towards tree stem), by hand excavation, or with specialized hydraulic or pneumatic equipment, cut cleanly with hand pruners or power saw, and immediately back-filled with soil. Avoid tearing, or otherwise disturbing that portion of the root(s) to remain.
•Construct a temporary fence as far from the tree stem (trunk) as possible, and at least as far as the drip-line of the tree. This fencing should completely surround the tree. Post no parking or storage signs outside / on fencing. Do not attach posting to the main-stem of the tree.
•Do not allow vehicles, equipment, pedestrian traffic; building materials or debris storage; or disposal of toxic or other materials inside of the fenced off area.
•Trees that will be impacted by construction may benefit from fertilization, ideally performed in the fall, and preferably prior to any construction activities. •Mulch rooting area with an acidic, organic compost or mulch. •Arrange for periodic (Biannual/Quarterly) inspection of tree's condition, and treatment of damaging conditions (insects, diseases, nutrient deficiencies, etc.) as they occur, or as appropriate.
•Individual trees likely to suffer significant impacts may require specific, more extensive efforts and/or a more detailed specification than those contained within these general guidelines.

Protective tree fencing shall specify the following:
(1)Size and materials. Six (6) foot high chain link fencing, mounted on two-inch diameter galvanized iron posts, shall be driven into the ground to a depth of at least two (2) feet at no more than 10-foot spacing. For paving area that will not be demolished and when stipulated in a tree preservation plan, posts may be supported by a concrete base. (2)Area type to be fenced. Type I: Enclosure with chain link fencing of either the entire drip- line area or at the tree protection zone (TPZ), when specified by a certified or consulting arborist. Type II: Enclosure for street trees located in a planter strip: chain link fence around the entire planter strip to the outer branches. Type III: Protection for a tree located in a small planter cutout only (such as downtown): orange plastic fencing shall be wrapped around the trunk from the ground to the first branch with 2-inch wooden boards bound securely on the outside. Caution shall be used to avoid damaging any bark or branches. (3)Duration of Type I, II, III fencing. Fencing shall be erected before demolition, grading or construction permits are issued and remain in place until the work is completed. Contractor shall Page 14 first obtain the approval of the project arborist on record prior to removing a tree protection fence.
(4)Warning sign. Each tree fence shall have prominently displayed an 8.5 x 11-inch sign stating:
"Warning—Tree Protection Zone-this fence shall not be removed and is subject to penalty according to Town Code 29.10.1025”
(5)Prior to the commencement of construction, install the fence at the drip-line, around any tree and/or vegetation to be retained which could be affected by the construction and prohibit any storage of construction materials or other materials, equipment cleaning, or parking of vehicles within the TPZ. The drip-line shall not be altered in any way so as to increase the encroachment of the construction.
(6)Prohibit all construction activities within the TPZ, including but not limited to: excavation, grading, drainage and leveling within the drip-line of the tree unless approved by the Director.
(7)Prohibit disposal or depositing of oil, gasoline, chemicals or other harmful materials within the drip-line of or in drainage channels, swales or areas that may lead to the drip-line of a protected tree.
(8)Prohibit the attachment of wires, signs or ropes to any protected tree. (9)Design utility services and irrigation lines to be located outside of the drip-line when feasible.
(10)Retain the services of a certified or consulting arborist who shall serve as the project arborist for periodic monitoring of the project site and the health of those trees to be preserved. The project arborist shall be present whenever activities occur which may pose a potential threat to the health of the trees to be preserved and shall document all site visits. (11)The Director and project arborist shall be notified of any damage that occurs to a protected tree during construction so that proper treatment may be administered.

Tree Removal Plan
Palo Alto Tree Removal and Replacement Ordinances

8.10.050 Removal of protected trees.

Completion of required mitigation measures included in the tree removal permit does not remove or shorten any such moratorium. A moratorium may be terminated early with approval of the urban forester or director of planning, and development services, as applicable, and may require additional mitigation measures. Mitigation measures included in the protected tree removal permit and any additional mitigation measures required to shorten a moratorium shall be imposed as a condition of any subsequent permits for development on the subject property.
(b)In the case of any development on a single-family (R-1) or low density (RE, R-2, or RMD) residential zoned parcel, other than in connection with a subdivision, a protected tree shall not be removed unless the tree is proposed for removal to accommodate an ADU constructed pursuant to Section 18.09.030, or because removal is necessary to allow an ADU constructed pursuant to Section 18.09.040 to achieve the minimum standards set forth in state law, or it is determined by the urban forester, on the basis of a tree report prepared by a designated arborist and other relevant information, that any of the following apply:
(1)The tree is so close to the proposed development that construction would result in the death of the tree, and there is no financially feasible design alternative that would permit preservation of the tree, where financially feasible means an alternative that preserves the tree unless retaining the tree would increase project cost by more than twice the reproduction cost of the tree or ten percent of the given project valuation, whichever is greater.
(2)Retention of one or more trees would result in reduction of the otherwise-permissible buildable area of the lot by more than twenty-five percent, and there is no financially feasible design alternative that would allow for preservation of the tree(s). For the purposes of this subsection (a)(2), a financially feasible design alternative means a design alternative that preserves the tree(s) and would not increase the project cost by more than twice the reproduction cost of the tree(s) or ten percent of the given project valuation, whichever is greater. All tree protection zones impacting buildable area are included in the reduction of buildable area calculation.
(3)The tree could be removed due to the conditions listed in Section 8.10.050(a)(1)(i), (ii), or (iii) and treatments or corrective practices are not feasible.
(c)In the case of development involving a proposed subdivision of land into two or more parcels, a protected tree shall not be removed unless determined by the urban forester, on the basis of a tree report prepared by a designated arborist and other relevant information, that either of the following apply:
(1)Removal is unavoidable due to restricted access to the property or deemed necessary to repair a geologic hazard (landslide, repairs, etc.), in which case only the protected tree or trees necessary to allow access to the property or repair the geologic hazard may be removed. (2)The tree could be removed due to the conditions listed in subsection (a)(1)(i), (ii), or (iii) and treatments or corrective practices are not feasible.
(d)In the case of development requiring planning approval under Title 18, and not included under subsections (b) or (c), a protected tree shall not be removed unless determined by the urban forester, on the basis of a tree report prepared by a designated arborist and other relevant information, that any of the following apply:
(1)Retention of one or more trees would result in reduction of the otherwise-permissible buildable area of the lot by more than twenty-five percent, and there is no financially feasible design alternative that would permit preservation of the tree(s), where financially feasible means an alternative that preserves the tree(s) unless retaining the tree(s) would increase project cost by more than twice the reproduction cost of the tree or ten percent of the given project valuation, whichever is greater. All tree protection zones impacting buildable area are included in the reduction of buildable area calculation. (2)The tree should be removed because it is dead, hazardous, or constitutes a public nuisance under Section 8.04.050. In such cases, the tree protection zone of the removed tree, or an equivalent area on the site, shall be preserved for mitigation purposes from development of any structure. (3)Discretionary development review determines that the final project follows right tree in the right place principles and would result in a net tree canopy increase on the property within fifteen years, and replacement of trees, shrubs, and plants either:
(i)Is consistent with Urban Forest Master Plan Goal 2: "Re-generated native woodland and riparian landscapes as the key ecological basis of the urban forest with focus on native species and habitat," or (ii)Uses climate adaptive, drought tolerant species.
(e)In any circumstance other than those described in subsections (a), (b), (c), or (d), a protected tree shall not be removed unless determined by the urban forester, on the basis of a tree report prepared by a designated arborist and other relevant information, that the tree is dead, is hazardous, or constitutes a public nuisance under Section 8.04.050.
(Ord. 5612 § 2 (part), 2024: Ord. 5557 § 4 (part), 2022: Ord. 5494 § 3, 2020: Ord. 4826 § 4, 2004: Ord. 4680 § 3, 2001: Ord. 4568 § 1 (part), 1999)

8.10.055 Tree replacement.
(a)In the event a protected tree is removed pursuant to Section 8.10.050(a)(1)(i), mitigation for the removed tree, replacement tree ratio, in lieu fees, or a combination thereof shall be determined by the urban forester, based on factors including but not limited to the species, size, location, and specific reason for removal of the protected tree, in accordance with the standards and specifications in the Tree and Landscape Technical Manual.
(b)In the event a protected tree is removed pursuant to Section 8.10.050 (a)(1)(ii), (iii), or (iv), (b), (c), (d), or (e), the tree removed shall be replaced in accordance with the standards and specifications in the Tree and Landscape Technical Manual, including but not limited to prioritization of locally native species, satisfaction of right tree in the right place principles, and incorporation of a secondary goal of net tree canopy increase on the property within fifteen years. The urban forester shall approve the number, species, size, and location of replacement trees.
(Ord. 5612 § 2 (part), 2024: Ord. 5557 § 4 (part), 2022) Tree Replacement Plan
This plan outlines the measures to compensate for the removal of eight native oak trees, seven of which are protected under the Palo Alto Tree Protection Ordinance. The plan adheres to the city’s requirements and ensures ecological value is maintained through appropriate replacement plantings.

Overview of Tree Removal
• Total Trees to Be Removed: 15 native oak trees
• Tags: 7, 11, 21, 37, 38, 39, 40, 56, 57, 58, 59, 60, 61, 62, 63 • These trees are either directly within the proposed building footprint or need to be removed due to being within the fire defensive zone (30ft from the property structure) as per the fire department
• Protected Trees: 14 trees are protected under Palo Alto City Ordinance.

Replacement Details
• Total Required Replacement Trees: 60 native oaks
NOTE:

In accordance with the CEQA Categorical Exemption Report dated February 2026, replacement trees shall not be planted in the identiﬁed environmentally sensitive areas of the site, which is natural habitat of the Monkeyﬂower Scrub. The remaining area of the site is only sufﬁcient to plant 30 replacement trees. As coordinated with the City Arborist, owner shall pay in-lieu replacement tree fees for the rest of the trees. • Species: Replacement trees will be either:
◦ Coast Live Oak (Quercus agrifolia)
◦ Blue Oak (Quercus douglasii)
◦ Valley Oak (Quercus lobata)
• Container Size: All replacement trees will be planted in 24-inch box containers to ensure successful establishment.
• Planting Locations: Replacement trees will be distributed across the property in suitable locations, ensuring adequate spacing and optimal growing conditions. Exact planting sites will be determined to avoid future conflicts with structures or utilities.

Replacement trees shall not be planted in the environmentally sensitive areas of the site as identiﬁed in the CEQA Categorical Exemption Report dated February 2026.

Planting Guidelines
• Soil Preparation: Planting holes will be amended with native soil and organic material as needed to promote healthy root growth.
• Irrigation: Temporary irrigation systems or manual watering will be provided for the first 3-5 years to ensure establishment.
• Mulching: A 3-4 inch layer of mulch will be applied around the base of each tree to conserve moisture and regulate soil temperature.

Maintenance and Monitoring Plan
• Health Inspections: Bi-annual or quarterly health inspections are recommended to be conducted by a certified arborist during the first two years. • Maintenance Actions:
◦ Deadwood and damaged branches will be pruned as needed. ◦ Irrigation will be adjusted based on seasonal rainfall.

Fire Defensible Zones
The subject property is located within Palo Alto’s Wildland-Urban Interface fire area, where defensible space is generally maintained within Zone 1, extending 0 to 30 feet from the building, and Zone 2, extending 30 to 100 feet from the building, as directed by the fire code official when site conditions warrant expanded clearance. An on-site coordination meeting was held with representatives of the Fire Department, during which the Fire Department required that all trees be removed from Zone 1, defined as within 30 feet of the building. The Fire Department further stated that it will not accept the placement of any new trees, including replacement trees, within Zone 1 or within Zone 2, extending from 30 feet to 100 feet from the building.

PAMC 8.10.092 Tree Removal in Wildland-Urban Interface Area Tree removal and relocation in the wildland-urban interface (WUI) area, as defined in Section 15.04.150, shall be subject to the provisions in Chapter 15.04. To the extent that Chapter 15.04 is inconsistent with this chapter, Chapter 15.04 shall control.

PAMC 15.04.150 Definitions
Section 202 Definition of Wildland-Urban Interface Fire Area Wildland-urban interface fire area is a geographical area identified by the State of California as a hazard in accordance with Public Resources Code Sections 4201 through 4202 and Government Code Sections 51175 through 51189, or other areas designated by the enforcing agency to be at a significant risk from wildfires. Within the city limits of the City of Palo Alto, “Wildland-Urban Fire Interface Area” shall also include all areas west of Interstate 280 and all other areas recommended as “Very High Fire Hazard Severity Zone” by the Director of the California Department of Forestry.

CCR 1299.03 Defensible Space
Defensible space is required to be maintained at all times whenever flammable vegetative conditions exist. One hundred feet (100 ft.) of defensible space clearance shall be maintained in two distinct zones as follows: “Zone 1” extends thirty feet (30 ft.) out from each building or structure, or to the property line, whichever comes first; “Zone 2” extends from thirty feet (30 ft.) to one hundred feet (100 ft.) from each building or structure, but not beyond the property line. The vegetation treatment requirements for Zone 1 are more restrictive than for Zone 2, as provided below.
(a) Zone 1 Requirements
(1) Remove all dead or dying grass, plants, shrubs, trees, branches, leaves, weeds, and pine needles from the zone, whether such vegetation occurs in yard areas around the building or structure, on the roof or rain gutters of the building or structure, or any other location within the zone. (2) Remove dead tree or shrub branches that overhang roofs, are below or adjacent to windows, or are adjacent to wall surfaces, and keep all branches a minimum of ten feet (10 ft.) away from chimney and stovepipe outlets. (3) Relocate exposed firewood piles outside of Zone 1 unless they are completely covered in a fire-resistant material.
(4) Remove flammable vegetation and items that could catch fire which are adjacent to or under combustible decks, balconies, and stairs.
(b) Zone 2 Requirements
(1) In this zone, create horizontal and vertical spacing among shrubs and trees using the “Fuel Separation” method, the “Continuous Tree Canopy” method, or a combination of both to achieve defensible space clearance requirements.
(2) In both the Fuel Separation and Continuous Tree Canopy methods, the following standards apply:
(a) Dead and dying woody surface fuels and aerial fuels shall be removed. Loose surface litter, normally consisting of fallen leaves or needles, twigs, bark, cones, and small branches, shall be permitted to a maximum depth of three inches (3 in.).
(b) Cut annual grasses and forbs down to a maximum height of four inches (4 in.). (c) All exposed wood piles must have a minimum of ten feet (10 ft.) of clearance, down to bare mineral soil, in all directions.

Fire Defensible Zones - Site Map

Job#5573
May 8th, 2026
1 Drainage Calculations
929 Laurel Glen Drive, Palo Alto

Conveyable Flow Rate (Manning’s Equation)

𝑄 = 𝐴 × (1.49
𝑛 ) × 𝑅
2 3 × 𝑆
1 2

𝐴6−𝑖𝑛𝑐ℎ 𝑃𝑉𝐶 = (𝜋 × 3 𝑖𝑛.2 ) × 1 𝑓𝑡2
144 𝑖𝑛2 = 0.196𝑓𝑡2

𝑃𝑊𝑒𝑡𝑡𝑒𝑑 𝑃𝑒𝑟𝑖𝑚𝑒𝑡𝑒𝑟 = (2 × 𝜋 × 3 𝑖𝑛) × 1 𝑓𝑡
12 𝑖𝑛 = 1.57𝑓𝑡

𝑅𝐻𝑦𝑑𝑟𝑎𝑢𝑙𝑖𝑐 𝑅𝑎𝑑𝑖𝑢𝑠 = 𝐴
𝑃 = 0.196 𝑓𝑡2

1.57 𝑓𝑡 = 0.125𝑓𝑡

𝑄6𝑖𝑛 𝑃𝑉𝐶 @ 2% = 0.196𝑓𝑡2 × ( 1.49

0.012) × 0.125𝑓𝑡
2 3 × 0.02
1 2

𝑄6𝑖𝑛 𝑃𝑉𝐶 @ 2% = 0.860 𝑓𝑡3
𝑠𝑒𝑐 (max 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒 𝑐𝑜𝑛𝑣𝑒𝑦𝑎𝑏𝑙𝑒)

Captured Area Site Runoff (Rational Method)

𝑄 = 𝐶 × 𝐴 × 𝐼10−𝑀𝑖𝑛

𝐼10−𝑀𝑖𝑛 = 2.42
𝑖𝑛
ℎ𝑟 (10-Year storm event – NOAA Atlas 14 Vol. 6 Ver. 2)

𝑄 = 2.42 𝑖𝑛
ℎ𝑟 × [(0.3 × 11,433𝑓𝑡2 × 1 𝑎𝑐𝑟𝑒
43560𝑓𝑡2) + (0.9 × 8,628𝑓𝑡2 × 1 𝑎𝑐𝑟𝑒
43560𝑓𝑡2)]

𝑄𝑀𝑎𝑥 𝐶𝑎𝑝𝑡𝑢𝑟𝑒𝑑 = 0.622 𝑓𝑡3
𝑠𝑒𝑐

Conveyance Sizing

0.622 𝑓𝑡3
𝑠𝑒𝑐 < 0.860 𝑓𝑡3
𝑠𝑒𝑐

The runoff captured in the system (for a 10-year storm event and 10-min Time of Concentration) is less than the maximum conveyable flow rate of a 6” PVC pipe sloped at 2%.

16April02 Impervious Area Worksheet
City of Palo Alto IMPERVIOUS AREA WORKSHEET
Public Works Engineering FOR LAND DEVELOPMENTS Phone: 650/329-2151 FAX: 650/329-2240 Applicants for all projects creating or replacing 500 square feet or more of impervious surface must fill out this worksheet and submit it to the Building Inspection Division prior to issuance of a building permit.

APN_______ -_______ -_________
Lot size (sq. ft.)________________
Title of Dwg. used to calculate revised impervious area_________________________ Land Use (Circle one): Residential Commercial Industrial Roadway For residential uses ⇒ Number of living units (Circle one): 1 2 3 or more Project Type (Circle one): New Development Redevelopment Watershed (Circle one): San Francisquito Matadero Barron Adobe SF Bay (see attached watershed map)
Purpose of Worksheet
The City of Palo Alto is collecting information on impervious surfaces created by land development projects in order to meet the requirements of its Stormwater Discharge Permit, issued by the San Francisco Bay Regional Water Quality Control Board. In addition, this infor mation is used to calculate the monthly Storm Drainage Fee for non-single-family residential properties (single-family residential properties are assessed a flat monthly Storm Drainage Fee).

Every developed land parcel in the City of Palo Alto is assessed a monthly Storm Drainage Fee. The fee is based upon the relative contribution of storm water runoff from each parcel to the City’s storm drainage system. A parcel’s relative contribution of storm water runoff is based upon the amount of “impervious surf ace” on that parcel. “Impervious surface” means that part of a developed parcel that has been modified to reduce the land’s natural ability to absorb and hold rainfall. It includes hard surfaces which cause water to run off the surface in greater quantit ies or at an increased rate of flow from the flow that existed under natural conditions prior to development. For example, common impervious surfaces include, but are not limited to, rooftops, walkways, patios, courtyards, driveways, parking lots, storage areas, concrete or asphalt paving, gravel roads, or any cleared, graded, graveled, paved, or compacted surfaces, or other surfaces which similarly impede the natural infiltration of surface water into the soil.

IMPERVIOUS AREA SUMMARY
Lot size (sq. ft.) ____________(a)
Existing impervious surface (sq. ft.) ____________(b) Existing percent impervious [line (b) ÷ line (a)] (%) _______(c) Area of impervious surface to be constructed (sq. ft.)
Ratio of newly constructed impervious sur face to existing impervious surface [line (d) ÷ line (b)] (%) _________________________(e) Approximate area of land disturbance during construction (sq. ft.) ___________ (f) Final impervious surface (sq. ft.)
(From “Impervious Area Calculation”, see back side.)

STAFF ONLY
Building Permit #________________ Building Permit Application Date________________ Reviewer__________________

Property Address________________________________________________________ Applicant Name________________________________________________________ 929 Laurel Glen Dr, Palo Alto
Ken Ngai
182 01354
184,201
5573-929_PGP.dwg
184,201
0 0
11,865
N/A
_____8,628___(d)
____8,628 Revised percent impervious [line (g)____(g) ÷ line (a)] (%) __4.68 __% __(h) Dwg. Date_____ 05-08-2026_______
16April02 Impervious Area Worksheet

IMPERVIOUS AREA CALCULATION
(Select one of the following methods and provide the required information) METHOD 1 METHOD 2
Calculate the area of impervious surface by measuring all Calculate the area of impervious surface by subtracting the impervious improvements. area of pervious surface from the total area of the parcel.

Sq. ft. Sq. ft.

Buildings +__________(1) Total area of parcel +__________(7) (from Assessor’s Book)
Parking/storage areas +__________(2)
(including driveways) Pervious Areas
Walkways Landscaping -___________(8)
Patios and courtyards +__________(4) Undisturbed areas -___________(9) Other (specify_____________________) -__________(10)
Total impervious area (sum #1 thru 5) Total impervious area (sum #7 thru 10) ___________ (11) METHOD 3
Calculate the area of impervious surface by adding (or
subtracting) the net change in impervious surface as a
result of construction to the impervious surface that existed prior to construction.

Sq. ft.

Existing impervious area +_________(12)
New Impervious Areas
Buildings +_________(13)
Parking/storage areas +_________(14)
(including driveways)
Walkways +_________(15)
Patios and courtyards +_________(16)
Other (specify______________________) +_________(17)
Impervious Area Removed
Buildings -__________(18)
Parking/st orage areas -__________(19)
(including driveways)
Walkways -__________(20)
Patios and courtyards -__________(21)
Other (specify_____________________) -__________(22)
Total impervious area (sum #12 thru 22) ______ _____(23) 3,473
1,508
2,478
Other (specify___W _a _ll _, _F _e _n _c _e,... _ _ _ _ _ __ __ ) +__1055___(3)
+__114__ (5)
___8,628__(6)
16April02 Impervious Area Worksheet
Instructions for Impervious Area Worksheet
Beginning May 1, 2002, applicants for all projects creating or replacing 500 square feet or more of impervious surface must fill out an Impervious Area Worksheet and submit it to the Building Inspection Division prior to issuance of a building permit. If you have questions about the form or the requested data, please consult with Public Works Engineering staff at the Development Center.

Line-by-Line Instructions
Property Address: Insert the street name and address for the subject property.

APN: Insert the Assessor’s Parcel Number (APN) for the subject property.

Applicant Name: Insert the name of the person applying for the building permit for the subject project.

Lot Size: Insert the size of the subject property in square feet.

Title of Drawing: Insert the name or number of the plan drawing used to calculate the impervious surface information.

Drawing Date: Insert the date of the drawing used to calculate the impervious surface information.

Land Use: Circle the appropriate land use for the subject property. If the property use is residential, circle the appropriate number of living units.

Project Type: Circle the appropriate project type. For purposes of this form, “new development” is construction on land that has never been built upon; everything else is considered “redevelopment”.

Watershed: Circle the appropriate storm drain watershed for the subject property. Use the map on the reverse side of this form to identify the correct watershed.

Existing Insert the amount of impervious surface (in square feet )currently on the subject property Impervious Surface: (or on the property prior to any recent demolition). See the “Purpose of Worksheet” section of the form for a definition of “impervious surface”.

Area of Impervious Insert the total amount of impervious surface (in square feet) to be constructed as part of Surface to be the subject project (both construction of new impervious surface over existing pervious Constructed: areas, as well as replacement of existing impervious surface with new impervious surface).

DO NOT INCLUDE routine maintenance work such as reroofing, resurfacing of existing paved areas, etc. in the calculation of impervious surface.

Approximate Area Insert the approximate area (in square feet) to be disturbed by construction operations of Land Disturbance: (including clearing, grading, excavating,, etc.) Final Impervious Insert the amount of impervious surface (in square feet) that will be on the subject property Surface: at the conclusion of the project (using the calculation worksheets on the back of the form). g as
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J un i per o Se r r a Bou l e v a r d
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Arastradero Road
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UNIVERSITY

STANFORD
Bay Watershed
San Francisco
Watershed
Creek
Adobe
Watershed
Barron Creek
Watershed
Matadero Creek
Creek Watershed
San Francisquito
Storm Drain
Watersheds within
the City of Palo Alto
This map is a product of the
City of Palo Alto GIS
This document is a graphic representation only of best available sources.

The City of Palo Alto assumes no responsibility for any errors.

CITY

OF PALO ALTO
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Watersheds (\\cc-prmtrak\Gis$\Data\View.Mdb)

1 Soils and Foundation Investigation for

New Single-Family House

Prepared for

Laurel Glen Drive. Palo Alto, CA 94303

APN 18254013 Lot 13

Lot 2 Track 6723 448 Book 48-51
184,201 SQFT 4.013 Acres
By

Farshad Safaian
12193 Brookglen Dr.

Sarataga, CA 95070

Project Number: 1392
Date: June 2024

Copies to: Mr Ken Ngai and Mike Amini by email

2 Subject: Soils and Foundation Investigation of Laurel Glen Drive. PaloAlto, CA 94303

Dear Mr. Ken Ngai

Address: Laurel Glen Drive. Palo Alto, CA 94303

In response to your request and authorization, we have completed a soil and foundation investigation for the above-mentioned project.

Based on our findings, it is our professional opinion that the site is suitable for the proposed New Single-Family House, provided that the recommendations of this report are carefully followed and are included into the project plans and specifications.

We appreciate the opportunity to be of service to you. If you have any questions concerning our findings and conclusions, please contact our office at your convenience.

Respectfully Submitted,

Farshad Safaian, P.E.

Registration # C66881

Copies to Mr. Mr Ken Ngai by email

3 TABLE OF CONTENTS

PAGE
Cover page ………………………………………………………………1
Cover letter ……………………………………………………………...2

1.0 Introduction ……………………………………………………………. 4

2.0 Site Location and Description …………………………………………. 4

3.0 Proposed construction …………………………………………………. 5

4.0 Field Investigation ……………………………………………………...6

5.0 Soil Conditions ………………………………………………………... 6

6.0 Laboratory Testing ……………………………………………………. 9

7.0 Geologic Setting & Faults ……………………………………...…….....7

8.0 Potential Geologic Hazards Evaluation ………………………… …….9

9.0 References ………………………………………………….…….. …..17

10.0 Conclusion & Recommendations………………………..……… ……..18

10.1 General ……………………………………..………....…..18

10.2 Grading ………………………………………..….............18

10.3 Foundations………….….....……………………….....…..20

10.3.1 Retaining Wall……….….....……………………….....…21

10.4 Slab-On-Grade……………………………………..……..24

10.5 General Construction Requirement ……………………....25

11.0 Construction Observation ………………………………………......26

12.0 Investigation Limitation ……………………………………….........27

Appendix I Consist of:

1. Soil Classification, Plasticity Index, and Sieve Analysis

2. Faults Maps

3. Earthquake Hazard Coefficient by Location

4. Soil Data, Plasticity Index, and Sieve Analysis

5. Ground motion (10% probability of being exceeded in 50 years) in fraction of g

6. Borings Log.

7. Earthquake Coefficients

4 1.0 INTRODUCTION

In accordance with your authorization our company has completed a soil and foundation investigation at the subject site for the proposed residence.

This soil report is not to perform Geology Hazard and Fults Rupture and lifelines such as water, sewer, gas, and power … that are not our study, and studies regarding these subjects are excluded.

This soil report was made from a geotechnical engineering point of view and limited to our recommendations in the above-mentioned soil report.

The scope of our work included the following:

1. Site reconnaissance by Professional Engineer.

2. Review of geologic reference maps.

3. Review of tentative, Topographic and Survey Maps

4. Soil classification

5. The preparation and writing of this report, which presents our findings, conclusions, and recommendations.

The purpose of this investigation was to evaluate the surface and subsurface soils at the site and provide recommendations to design the proposed new two-story Single-Family House. Based on the data and information obtained, we have provided recommendations for foundation design and grading criteria for the design of the above buildings.

Our findings indicate that the proposed above building is feasible from a geotechnical standpoint provided the recommendations in this report are included in the project plans and specifications and adhered to during and after construction.

2.0 SITE LOCATION & DESCRIPTION

The site is rectangular in shape and located as APN 18254013 Lot 13 Laurel Drive Palo Alto CA 94304. It is bounded on the three sides by residential properties in the north, east and west sides.

The site is almost steep slope from south to the north and building will be constructed on slope.

The project consists of constructing residential building south side one story and north side 2 stories. We anticipate that structural loads will be relatively light as is typical for this type of construction.

The above description is based on a site reconnaissance by the Soil Engineer.

5 3.0 PROPOSED CONSTRUCTION

This soil report is not to perform Geology Hazard and Fults Rupture and lifelines such as water, sewer, gas, and power … that are not our study, and studies regarding these subjects are excluded.

This soil report was made from a geotechnical engineering point of view and limited to our recommendations in the above-mentioned soil report.

The proposed project is a new Single-Family House, Latitude = 37.373765°N, Longitude = -122.1782° W.

Vicinity Map

6 Vicinity Map

4.0 FIELD INVESTIGATION

The field investigation was performed on 12/3/2023 (couldn’t soil sampling because of raining and slippery steep slope and couldn’t installing the rig for soil sampling) and 2/21/2024 and 4/29/2024 (two more soil samples borings and get soil samples exactly under the building area) and included a site reconnaissance by the Soil Engineer and drilling soil sampling excavation.

Soil sampling was performed with minuteman 3-1/4” in diameter Continuous driven Flight Auger and constantly hammered with 140 lb weight.

On boring B1 during drilling soil sampling excavation encountered bedrock at 2’ ft (this area was flattened) and continued until 8 feet below the existing ground surface to make sure siltstone rock was thick enough, and in boring B2 encountered rocks at 12’ ft and drilled to the depth of 20’ ft, and in boring B3 encountered rocks at 12’ ft and drilled to the depth of 15’ ft, and in boring B4 encountered rocks at 10’ ft and drilled to the depth of 3’ ft.

Visual classifications were made from the samples in the field. As the excavation proceeded, bulk samples were obtained.

5.0 SOIL CONDITIONS AND DATA
The soil conditions were derived from our site reconnaissance and the information and samples obtained from drilled borehole below the new building and between building and Laurel Glen Drive.

Visual classifications were made from cutting and the samples in the field. Classifications made in the field were verified in the laboratory after further examination and testing. The results are shown on the Logs of Test Boring.

7 Borehole B-1 – 30 ft from the Laurel Glen Drive:
- Topsoil 0” to 24”, vegetated, dark greyish brown, sandy silty clay, very moist, firm. - 2’ to 5’, brownish yellow, encountered bedrock at 2’, silt/sandstone, moist, SPT 20/30/46. - 5’ to 8’, yellow, weathered rock, silt/sandstone, SPT 30/50 for 6”. - Stopped drilling at 8 ft.
- No water encountered.

Borehole B-2 - 60 ft from the Laurel Glen Drive:
- Topsoil 0” to 24”, vegetated, dark greyish brown, sandy silty clay, very moist, firm. -2’ to 5’, yellowish brown, sandy silty clay, moist, SPT 5/7/12. -5’ to 10’, yellowish brown, sandy silty clay, moist, SPT 10/12/20. -10’ to 15’, yellowish brown, sandy silty clay, moist, encountered weathered rock at 12 ft SPT 16/20/30.
-15’ to 20’, brownish yellow, weathered rock, moist, SPT 30/32/35. - Stopped drilling at 20 ft.
- No water encountered.

Borehole B-3 - under the main building area:
- Topsoil 0” to 24”, vegetated, dark brown, sandy silty clay, very moist, medium stiff, SPT 4/5/7. -2’ to 6’, yellowish brown, sandy silty clay, moist, firm, SPT 5/7/13. -6’ to 10’, brownish yellow, silty clayey, sand, very moist, SPT 9/15/21. -10’ to 15’, yellowish brown, sandy silty clay, moist, encountered weathered rock at 12 ft SPT 34/43/50 for 5”.
- Stopped drilling at 15 ft.
- No water encountered.

Borehole B-4 - under the garage area:
- Topsoil 0” to 24”, vegetated, dark brown, sandy silty clay, very moist, stiff, SPT 5/7/10. -2’ to 6’, yellowish brown, sandy silty clay, very moist, firm, SPT 10/17/20. -6’ to 10’, brownish yellow, silty clayey, sand, very moist, SPT 29/40/60. -10’ to 15’, yellowish brown, sandy silty clay, moist, encountered weathered rock at 10 ft SPT 34/43/50 for 5”.
- Stopped drilling at 15 ft.
- No water encountered.

Soil Data – Typical Properties of Compacted Soils from 0’ to 12’

A): Soil Specification on Top:

Soil Classification, SC-SM, Silty Clayey Sandy between 0’ to 12’. 1- Maximum dry density ϒd=120 PCF with optimum moisture Woptimum=13%, ϒt=136PCF
2- Cohesion as saturated C’=300 PSF.
3- Effective stress envelope ϕ’=33 degrees.
4- Coefficients of active pressure, Ka=0.30 and passive pressure, Kp=3.40 for flat backfill behind the retaining wall.

8 5- Modulus of Subgrade Reaction Ks=100 PCI
6- Sieve analysis in boring #3 B-3 at 2ft, Gravel G=1%, Sand S=51%, Fine F=48%. 7- Sieve analysis in boring #4 B-4 at 2’ to 6’ft, Gravel G=1%, Sand S=62%, Fine F=37%.
8- To get started grading first remove the top 12 inches containing fill soil and vegetation from top of the existing grade.
9- Stripping depth of 12 inches and five (5’) feet beyond the building lines. Scarifying 8” in fill areas, then moisturize to optimum moisture, after mixing should be compacted to 95%, before gets started, soil engineer should visit the jobsite to determine all stripping’s thickness.
10- The setback of piers from the slope should be minimum 10 ft (in flattened areas). 11- The minimum piers depth in the rock is 12 ft therefore total depth of piers are 24’ ft. 12- Actual required piers are 18” in diameter and should be minimum 23’ ft and minimum 12 feet in the rock.
13- Allowable foundation pressure 2000 PSF, Lateral Bearing below natural grade 150 PCF (PSF/F), and lateral sliding resistance 100 PSF.
14- Piers skin friction will be 350 PSF.
15- The lateral sliding coefficient of friction is 0.25. 16- Design Lateral Soil Load for at-rest pressure is 100 PCF.

9 Borings Location

6.0 LABORATORY TESTING
All samples were visually classified in accordance with the Unified Soil Classification System per ASTM D-2487 and/or D-2488 to verify the field classification. Samples obtained from boring, were sent to laboratory to determine:

-The moisture and density per ASTM D-2937
-The Sieve Analysis were determined per ASTM D-422

7.0 GEOLOGIC SETTING & FAULTS
Geologic Setting:

Generally, the site area is located on the North American Plate just northeast of plate boundary, southern portion of the Santa Clara Valley formed by the San Andreas Fault. Crustal strain produced by movements along the San Andreas and subsidiary faults has created pervasive, northwest- trending complex folding and faulting. The Santa Clara Valley is a broad, northwest-trending, alluvial-filled basin between the Santa Cruz Mountains to the west and the Mount Hamilton Range to the east. The alluvial sediments forming the valley floor are divided into older alluvial deposits that make up the majority of the valley fill, with younger deposits of alluvium confined to the active stream

10 channels. The Quaternary age-old alluvium consists of inter-layered, poorly sorted gravel, sand, silt, and clay.

Geologic Map of California
Kjf Rocks
Franciscan Complex, Cretaceous and Jurassic sandstone with smaller amounts of shale, chert, limestone, and conglomerate. Includes Franciscan mélange, except where separated.

Mzv Rocks
Mesozoic Metavolcanic Rocks
Undivided Mesozoic volcanic and Metavolcanic Rocks. Andesite and rhyolite flow rocks, greenstone, volcanic breccia, and other pyroclastic rocks, in part strongly metamorphosed.

Includes volcanic rocks of Franciscan Complex: basaltic pillow lava, diabase, greenstone, and minor pyroclastic rocks.

-The geologic formation underlying this site and its vicinity has been mapped by USGS geologic map of California.

Faults:

According to published maps, the site is located at east of the active San Andreas Fault with Coordinates: Latitude = 37.556° N, and Longitude = -122.178056° W

Earthquake Magnitudes and
Historical Earthquakes Nagi
Residence
Los Altos Hills,
California

Fault
Maximum
Magnitude (Mw)
Historical
Earthquakes
Estimated
Magnitude
San Andreas 7.9 1989 Loma Prieta 6.9
1906 San Francisco 7.9
1865 N. of 1989 Loma Prieta Earthquake 6.5
1838 San Francisco-Peninsula Segment 6.8
1836 East of Monterey 6.5
Hayward 7.1 1868 Hayward 6.8
1858 Hayward 6.8
Calaveras 6.8 1984 Morgan Hill 6.2
1911 Morgan Hill 6.2
1897 Gilroy 6.3
San Gregorio 7.3 1926 Monterey Bay 6.1

11 8.0 POTENTIAL GEOLOGIC HAZARDS
Landslides:

We observed some evidence of landslides on the site area during our site reconnaissance, of course the area is categorized as a “landslide”.

Fault Rupture:

The area is within the “near source” zone of the San Andreas (distance 2.0 mi), Calaveras (distance 21.0 mi) and Hayward (distance 16.5 mi) Faults. Nevertheless, no active faults have been mapped to cross the site.

Seismic Shaking:

The site is in the seismically active San Francisco Bay Area. Several major earthquakes, which have been produced by movement on one of the principal active faults, affected the region during historic time. These earthquakes include the June 1838 which caused Damage to San Francisco and Santa Clara and the 1906 San Francisco and recent 1989 Loma Prieta earthquakes originating on the San Andreas Fault.

Considering the past seismic history of the region, the site will be affected by strong seismic shaking during the expected lifetime of the proposed building. The intensity of shaking is determined by the distance of the site to the seismic source and the properties of the material along the path of the transmitted energy.

TABLE 1.1
ASCE7-16 SEISMIC DESIGN PARAMETERS
Parameter Values CBC Reference
Site Class D Section 1613.2.2
SS 2.573 MCER ground motion
(period=0.2s)
S1 0.908 MCER ground motion
(period=1.0s)

Site Coefficient, Fa 1.2 Table 1613.2.3(1)
Site Coefficient, Fv null Table 1613.2.3(2)
Site Class Modified MCER Spectral Response
Acceleration (short), SMS

3.088 Site-modified spectral
acceleration value
SDS 2.058 Numeric seismic design value
at 0.2s SA
SD1 null Numeric seismic design value
at 1.0s SA
5% Damped Design Spectral Response
Acceleration (1 sec), SD1
null
Peak Ground Acceleration for this site is 1.059 g.

12 Liquefaction:

Soils, which are most susceptible to liquefaction, are saturated loose, fine-grained, uniformly graded, sands and silts. The project is not categorized as “susceptible to liquefaction” by USGS.

In addition, because of the presence of clay near the surface soil, the probability of liquefaction could be considered very low to zero.
1- Liquefaction Potential:

Soils, which are most susceptible to liquefaction, are saturated loose, fine-grained, uniformly graded, sands and silts, when Soil Water Content divided by Liquid Limit is less than 0.85 (Wc/LL<0.85) and percentage of fine in the soil (passing the sieve #200) is more than 15% and soil compacted, we conclude that the probability of liquefaction is low to zero at this site.

Lateral Spreading & Differential Compaction:

Although the soils are generally silty sandy clay and siltstone, and because of the presence of slope and free faces behind the foundation, we conclude that the probability of lateral spreads or differential Compaction affecting the site during an earthquake is not low.

Settlement
Estimated settlement.

The total settlement of an individual foundation will vary, depending upon the plan dimensions of the foundation system and the actual load supported on them. Based on the anticipated foundation dimensions and loads, we estimate the total settlement due to structural loads of foundations designed and constructed in accordance with the preceding recommendations to be about zero.

Differential settlement is anticipated to be on the order of about zero.

Earthquake Zone of Requierd Investigation

13 Landslide Zone- This area is in Landslide Zone
Landslide Zone- This area is in Landslide Zone

14 Fault Activity Map: San Andereas, Hayward, Calaveras, and Monte Vista Faults

Distance to San Andreas Fault = 2.0 mi

15 Distance to Hayward Fault = 16.5 mi
Distance to Calaveras Fault = 21.0 mi

Quaternary Fault (age undifferentiated) Site is located between San Andreas and Hayward/Calaveras faults /east of San Andreas and west of Hayward/Calaveras faults next to Monte Vista Fault.

16 San Andreas and Hayward/Calaveras faults are quaternary fault age undifferentiated, and San Andreas, Hayward/Calaveras Faults are active faults along which historic (last 200 years) displacement has occurred.

This area is close to Monte Vista Fault and has landslide.

Kjf Rocks
Geologic Map of California
Kjf Rocks
Franciscan Complex, Cretaceous and Jurassic sandstone with smaller amounts of shale, chert, limestone, and conglomerate. Includes Franciscan mélange, except where separated.

Includes volcanic rocks of Franciscan Complex: basaltic pillow lava, diabase, greenstone, and minor pyroclastic rocks.

17 Mzv Rocks

9.0 REFERENCES

9.1 Geologic Map of California

9.2 USGS MAPS

9.3 NAVFAC 7.1 and 7.2

9.4 Caltrans Specifications

9.5 maps.conservation.ca.gov/geologichazards/

18 10.0 CONCLUSIONS AND RECOMMENDATIONS

10.1 GENERAL

10.1.1 The site is suitable for the proposed New two-story Single-Family House, if provided recommendations in this report are incorporated into the project plans and specifications.

10.1.2 After the plans have been developed, we recommend that these plans be reviewed by our soil engineer for conformance to the intent of this report.

10.1.3 Field observation and testing during the grading and foundation excavation operation must be provided by our soil engineer and/or his representatives. Any work performed without the full knowledge and observation of our soil engineer will render the recommendations of this report invalid.

10.2 GRADING
Site Clearing & Preparation:

10.2.1 After flattening the slope, the site should be cleared of all obstructions and deleterious materials such as abandoned utility lines and loose soil. After clearing, the fill areas should be stripped of all organic laden soil. This sloped area should be flattened 10 ft further building lines (actually the building line or piers shall have 10 ft setback from the top of slope to have enough resistance force). Then we estimate stripping depth of 12 inches and five (5’) feet beyond the building lines. Final stripping depth shall be determined by the Soil Engineer in the field. Organic-laden materials should be removed from the site or stockpiled for use in landscape areas only.

10.2.2 At the completion of the clearing, flattening, and stripping operations, all fill areas shall be scarified by minimum depth of 8 inches; moisture-conditioned by aerating or adding water and compacted in accordance with the requirement of this report (shall be determined by soil engineer as needed).

10.2.3 Soft areas encountered shall be excavated to firm base prior to commence of fill operation.

This should include any soft fill or native material. Actual required depth to be determined in field by the Soil Engineer.

On-Site & Import Material:

10.2.4 All on-site material having an organic content of less than 1% by volume and free from other deleterious materials are suitable for use as fill on site. All fill material should have a maximum particle size of 3 inches with no more than 15% larger than 2.5 inches. The soil engineer needs to test any fill material used on the job site.

10.2.5 Any import fill which is predominately granular in nature and with plasticity index of 12 or less, Liquid Limit of 30% or less, Expansion Index of 20% or less, Resistance R-Value not

19 less than 25, % Passing Sieve #200 between 10% and 20% and maximum Rock size three (3) inches can be used. The Soil Engineer should give final approval of any import fill material prior to placement. The contractor shall notify our company 5 working days in advance of his intention to import soil from any other source outside the site area and shall permit the engineer to sample as necessary for the purpose of performing tests to establish the qualities of the material.

Compaction:

10.2.6 After preparation of the native ground soils, the site may be brought to the desired finish grade by placing on-site native material in lifts not to exceed 6” inches for hand operated mechanical compactors and not to exceed 8” inches for heavy equipment compactors in uncompacted thickness and compacted to a minimum of 95% as determined by ASTM D- 1557-91 laboratory testing procedure. In the traffic areas, the upper twenty-four (24”) inches of the sub-grade and the aggregate base rock should be compacted to a minimum relative compaction of 95%.

10.2.7 The moisture of the fill material should be 0 to 3% above optimum and sufficient to obtain the required density. Water should be added, or the fill material shall be aerated by blading or other satisfactory method in order to have acceptable range for moisture.

None-Uniform Soil (Cut/fill):

10.2.8 It is highly emphasized that uniform soil conditions are provided underneath all fill construction. Cut/fill or non-uniform soil conditions areas should be excavated and replaced with uniform engineered fill material in order to minimize differential movement. Our engineer or his representative needs to observe this operation.

Surface and Subsurface Drain:

10.2.9 All surface water should be collected by a drain system (i.e., catch basin and a solid drain line), which discharges the water away from the building. Flexible drainpipe is not acceptable for use in the surface and subsurface water drainage because of the likelihood of damage to the pipe during installation and the difficulty of future cleaning with mechanical equipment without damaging the pipe. Surface and subsurface drainage pipes should be rigid plastic pipes.

10.2.10 Studying and preparing this report for Surface and Subsurface Drainage is not part of this report and should be done by others.

Observation & Testing:

10.2.11 Quality, density, and geometry of construction stages in the field should be performed by Soil Engineer or his representatives using relevant tests. The testing program number of tests and frequency of testing will be determined by the Soil Engineer or applicable specifications.

20 10.3 DEEP FOUNDATIONS

This area is located next to San Andreas and Calaveras Faults and has landslides and creep.
(This soil report was made from a geotechnical engineering point of view and limited to our recommendations in the above-mentioned soil report.

This soil report is not to perform Geology Hazard and Fults Rupture and lifelines such as water, sewer, gas, and power … that are not our study, and studies regarding these subjects are excluded.)

10.3.1 DEEP FOUNDATION

The piers’ setback from the top of slope should be minimum 10 ft. (on the flattened area) to have enough passive forces.

1. Due to proximity to the San Andreas fault, steep slopes at the project site and landslides of the area.

2. The proposed two-story New Building with garage structure will be supported by piers and grade beams footing. Criteria for this type of foundation are presented in the following paragraphs.

3. Any proposed building and retaining walls should be supported on piers and grade beams foundation system.

4. The piers’ setback from the top of slope should be minimum 10 ft. (on the flattened area) to have enough passive forces.

5. Foundations for new buildings and retaining walls that support structures should be supported on cast-in-place drilled piers with a minimum diameter of 18” inches that extend a minimum of 12 feet into hard bedrock, the actual length of piers from the existing surface to the bottom of piers shall be 23’ feet. For piers located within 10 ft from the top of the slope or within the slope, the embedment shall be calculated from a 10-foot daylight line. The actual length of piers shall be determined by geotechnical engineer at the time of drilling based on the bedrock contact depth.

6. - The piers should be designed as friction piers in bedrocks. An allowable skin friction of 300 psf for dead plus live load with 1/3 increase allowable for transient wind or seismic, neglecting the end bearing, loading may be used in the design of the piers. The upper 5 feet of the piers should not be considered to provide any support.

7. Creep pressure is 56 pcf Inverted EFW (ie. 0 psf at the base of the soils, native stiff soil interface) up to a maximum pressure at the ground surface on top five (5’) feet.

8. Lateral load capacity on piers can be evaluated using a passive equivalent fluid pressure of 360 pcf, acting on 1.6 times the width of the pier, for the length embedded in bedrock only.

9. Passive pressure in the upper clayey soils shall be ignored and replaced with an active equivalent fluid pressure of 56 pcf, due to soil creep.

21 10. -All exterior piers and interior piers (No Exceptions) should be tied together with reinforced grade beams with 12” width and 18” height (12”x18”) that rebars will be determined by structural engineer.

11. -Provided a minimum spacing of three (3) piers diameters is maintained between piers, no reduction in allowable soil parameters is required. The designer should consult with the Soil Engineer for closely spaced piers for supplemental recommendations.

12. - The bottom of the piers should be dry and free of all loose cutting and soil fall, prior to concrete placement. Pier drilling operations and concrete placement should be coordinated so that the pier holes are left open for a minimum amount of time.

13. - Actual piers depth and spacing should be determined by the Structural Engineer based on actual loading conditions. Pier and grade beam reinforcement will depend on the loading.

14. Factor of safety for design of deep foundation for downward loads for permanent piers is 3.

Retaining Walls

Retaining walls are incorporated into the structural new building and landscaping construction must be supported on drilled piers designed and constructed in accordance with recommendations provided above.
1- Landscaping’s walls should be designed to resist lateral pressures equivalent to those exerted by a medium having an equivalent fluid weight active pressure 60 pcf for flat backfill, and active pressure 75 pcf for backfill with gradients up to 2:1 (H:V). In addition to any pressures exerted during compaction of backfill and all pressures due to any surcharge loads and seismic.
2- Retaining walls those are part of building foundation of structural building should be designed as at-rest lateral soil load equal to equivalent fluid weight of 100 PCF (pound per square foot per foot) 3- Garage Retaining Walls
walls should be designed to resist lateral pressures equivalent to those exerted by a medium having an at-rest design lateral soil load equivalent fluid weight of 100 pcf for flat backfill. In addition to any pressures exerted during compaction of backfill and all pressures due to any surcharge loads.

If garage is constructed over empty spaces or rooms, uniform surcharge 100 PSF shall be considered.

22 4- Basement Retaining Walls
walls should be designed to resist lateral pressures equivalent to those exerted by a medium having an at-rest design lateral soil load equivalent fluid weight of 100 pcf for flat backfill. In addition to any pressures exerted during compaction of backfill and all pressures due to any surcharge loads and seismic.
5- Seismic force on retaining walls
Following parameters are our recommendation to calculate seismic forces on retaining walls, final results will be determined by structural engineer, and structural engineer is responsible for seismic forces on retaining walls.
- Any retaining walls incorporated into the two-story new building and landscaping should be designed to resist lateral pressures from seismic forces.

Lateral seismic forces on retaining walls incorporated into the residence may be calculated based on the simplified Mononobe-Okabe relationship proposed by Seed and Whitman (1970).
∆PAE ~ (⅓) Kh γH2
where ∆PAE is the dynamic component, Kh is the horizontal ground acceleration divided by/gravitational acceleration (horizontal peak ground acceleration = 1.059g); γ is the total soil density (136 pcf); and H is the height of the wall in foot. A triangular stress distribution should be assumed for the seismic loading with the vertex at the base of the wall and the resultant 0.6H from the base of the wall.

For retaining walls shorter than 6 ft seismic loads does not need to be considered.

Retaining Wall Sub-Drains

10. The above criteria are based on fully drained conditions. It is imperative that all walls be fully drained.

11. In order to achieve fully drained conditions, a drainage filter blanket must be placed behind the wall. The blanket should be a minimum of 12 inches thick and should extend the full height of the wall to within 12 inches of the surface. If the excavated area behind the wall exceeds 12 inches, the entire excavated space behind the 12-inch blanket should consist of compacted engineered fill or blanket material. The drainage blanket material should consist of granular ¾” clean crushed rock and drain pipe fully encapsulated in geo-textile filter fabric (such as Mirafi 140 N or

23 similar). A 4-inch perforated drainpipe should be installed in the bottom of the drainage blanket face down and should be underlain by 2 inches of filter type material. A 12-inch cap of native soil should be placed over the blanket. For areas where the drainage blanket will be capped with concrete, the crushed rock may be brought to sub-grade elevation, and the concrete cast directly onto the crushed rock.

12. Damp-proofing of the basement walls (such as Miradrain 2000 or 6000) should be included in areas where wall dampness and efflorescence would be undesirable.

13. The drainage pipe used below the basement pad and behind the retaining walls should be 4” schedule 40 perforated pipe to collect the drainage water and route it to a properly designed pumping system.

Interconnecting pipes are needed to be 4” solid schedule 40 pipes. No flexible pipes are acceptable.

FARSHAD SAFAIAN Structural & Geotechnical Services
12193 Brookglen Dr. Saratoga, CA 95070 Cell # (408)505-3165

24 10.4 Slab-on-grade (interior, exterior, sidewalk, flatwork)

Surface soils in the site have potential for volume change due to change in moisture content. This volumetric change may cause cracking and differential settlements in slab-on-grade and flatwork supported on soil. We order to avoid these problems the subgrade for slabs should be moisture conditioning to slightly above optimum moisture content, and the top 6 inch of the subgrade should be replaced by imported non-expansive fill material (such as ¾” clean crushed rock), Soil Engineer will determine the thickness of replacement on site. Moisture below slabs can be sealed in using edge grade beams or moisture barriers.

Moisture penetration through the slab can be reduced by placing a 6-inch-thick layer of 3/4 inches clean, free draining crushed rock below the slab (recycled crushed rock is not acceptable) and should be placed on the compacted subgrade instead of 6 inches soil replacement mentioned in the previous paragraph. The rock should be compacted in-place with vibratory plate. The subgrade soil should be compacted to at least 95% relative maximum density and can be further prevented by placing a plastic vapor barrier, at least 15-mil thick, over the six inches rock and covering it with 2 inches of damp clean sand to protect it during construction for inside of building.

We recommend Interior slab and garage slab shall be six inches thick but final slabs thickness will be determined by structural engineer.
.

We have no load information and data for the above building so thickness and detail of interior concrete slab-on-grade will be determined by structural engineer, and we are not responsible for it.

Exterior Concrete slab-on-grade floors and exterior sidewalk flatwork shall be at least 4 inches in thickness and reinforced with a minimum 12”x12” No. 4 welded wire mesh, or equivalent in deformed bars. Crack control joints should be specified at an appropriate distance in both directions and reinforcing steel should extend through the joints to provid resistance against differential movement.

The drain rocks or gravel shall meet the gradation requirement.

Table
Free-Draining Drain Rocks or Gravel Gradation Requirement Sieve Size Percentage Passing Sieve
1 inch 100
¾ inch 90-100
No. 4 0-10
No. 200 0-3

25 Foundation Clearances From Slopes

Foundation Clearances From Slopes

10.5 GENERAL CONSTRUCTION REQUIREMENTS

Surface Drainage & Irrigation

10.5.1 All finish grades should provide a positive gradient to an adequate discharge point to provide rapid removal of surface water runoff away from all foundation and retaining wall. No ponding of water should be allowed on the pad or adjacent to the foundations.

These lot slopes should be provided to aid in the removal of water from the pads and to reduce the amount of water which may seep beneath the building. Surface drainage should be provided as designed by the project engineer or project civil engineer and always maintained by the property owner after work.

10.5.2 Consideration should be given to grading the crawl space under the building (raised floor, shallow foundation system) and to provide an outlet to remove any water trapped under the building.

10.5.3 All finish grade drainage swales must be cut into compacted finish grade. Construction of the drainage swales using incompact loose surface fill does not meet the recommended grading requirement.

10.5.4 Continuous roof gutters are recommended. Downspouts from the gutters may be provided with adequate pipe conduits to carry storm water away from the foundation and graded areas, thus reducing the possibility of soil saturation adjacent to the foundations and engineered fill.

10.5.5 Planters should be avoided adjacent to the foundation. Should planters be constructed, foliage requiring little irrigation should be considered to further reduce the amount of water that could affect the foundation. Alternatively, a watertight planter box with controlled discharge should be provided.

26 10.5.6 Any utility trenches extending under the building areas should be backfilled with native on- site soils or approved import materials. Backfill should be properly compacted to prevent water migration through the utility trenches extending underneath the structure.

10.5.7 Utility trenches underneath all traffic areas must be backfilled with native or approved import material and compacted to a relative compaction of 90% to within 12 inches of the sub-grade.

The upper 12 inches should be compacted to 95% relative compaction. Backfilling and compaction of these trenches must meet the requirement set forth by the City of Palo Alto, Department of Public Works.

10.5.8 The soil generated from trenching may be used as backfill with the exception of cobble greater than 6 inches in largest dimension. Compaction of the trench backfill should comply with the requirements set forth by the City of Palo Alto, Department of Public Works.

10.5.9 Bedding and embedment materials to be used around underground utilities pipes should be well graded sand or gravel and should be placed and compacted in accordance with the project specifications, local requirement, and governing jurisdictions. All the underground utility trenches on-site must be compacted to a minimum of 95% relative compaction per requirements of the local agency / project soil engineer and in accordance with the test procedure ASTM D1557-latest edition.

Trench Shoring & Temporary Slopes:

10.5.10 Applicable safety standards require that trenches more than 5 feet must be properly shored or that the walls of trench slope back to provide safety for installation of lines. If trench wall sloping is performed, the inclination should vary with the soil type. The underground contractor should request an opinion from the Soil Engineer as to the type of soil and the resulting inclination. Slopes of 1:1 (horizontal to vertical) may be utilized for stable cohesive soil while 2:1 will be required for the more granular loose soil.

11. CONSTRUCTION OBSERVATION

The performance of any project is dependent upon the construction procedures and quality.

Geotechnical observations should be carried out by this firm to permit correlation between the preliminary soil data obtained during our investigation and the actual soil conditions encountered during construction. Construction observation performed by this firm will minimize the possibility of understanding by others of both the letter and spirit of our report.

This will enable us to note any subsurface conditions different than those forming the basis of our recommendations. It is noted that any of these observations, testing and/or inspections are extra and are not covered by the basis charge of this report. The importance of careful adherence to the report recommendations cannot be overemphasized. The use of this report by others presumes that they have verified all information and assume responsibility for the total project.

Therefore, construction observation should be provided during clearing, demolition, grading, foundation excavation, trench excavation, trench backfill, sub-grade preparation,

27 base rock placement and all other construction operations referred to in the report or the project plans and specifications.

12.0 INVESTIGATION LIMITATIONS

-Our services consist of professional opinions and recommendations made in accordance with the generally accepted Geotechnical Engineering principles and practices. The analysis and the recommendations submitted in the report are based on our site recommendations, the soil information derived from the exploratory borings, the proposed development, and the assumption that the subsurface conditions do not deviate from the anticipated conditions. -This warranty is in lieu of all other warranties either expressed or implied. -Unanticipated subsurface conditions are commonly encountered and cannot be fully determined by taking soil samples from exploratory borings. Different soil conditions may require that additional expenditure be made during construction to attain a properly constructed project.

Therefore, a contingency fund is recommended to accommodate possible extra costs. -This report has been prepared to assist in the evaluation of the property and to assist the architect and engineer in their design. In the event any changes in the design or location of the facilities are planned, or if any variation or undesirable conditions are encountered during construction, changes should be noted and reviewed by the Soil Engineer for approval.

Standard maintenance should be expected after the initial construction has been completed.

Should ownership of this property change hands, the prospective owner should be informed of this report so as not to change the grading or block drainage facilities of this project and the necessary steps are also taken to assure that the recommendations are followed in the field.

28 APPENDIX

Project Name: Laurel Glen Ave. Palo Alto, CA 94303

Owner: Mr. Mr. Mr Ken Ngai

Ordered by: Mr. Mr Ken Ngai

Owner Address: Laurel Glen Ave. Palo Alto, CA 94303

29 Sieve #

Passing %

97.81 #8

94.75 #16

89.42 #30

82.54 #50

75.86 #100

72.35 #200

70.00 Gravel = 1.5% Sand = 25.75% Fine = 70.99%

LL=36.8%, PL=15.4% and PI=21.4

Soil Classification: CL, Lean Clay with Sand

Boring B1-Sieve Analysis at depth 2 ft.

30 Boring B1-Sieve Analysis at depth 2 ft.

31 Boring B1-Plasticity Index at depth 2 ft.

32 Sieve #

Passing %

99.31 #8

96.47 #16

88.55 #30

77.57 #50

65.99 #100

55.96 #200

49.02 Gravel = 1% Sand = 51% Fine = 48%

LL=41.3%, PL=21.8%, and PI=19.5

Soil Classification: SC-SM, Silty Clayey Sand

Boring B3-Sieve Analysis at depth 2 ft.

33 Boring B3-Sieve Analysis at depth 2 ft.

34 Boring B3-Plasticity Index at depth 2 ft.

35 Sieve #

Passing %

99.64 #8

97.85 #16

92.63 #30

81.44 #50

65.22 #100

48.84 #200

37.51 Gravel = 1% Sand = 62% Fine = 37%

Soil Classification: SC-SM, Silty Clayey Sand

Boring B4-Sieve Analysis at depth 2’ to 6’ ft.

36 Boring B4-Sieve Analysis at depth 2’ to 6’ ft.

37 Faults Map

38 39

Earthquake Coefficients, PGA=1.059

40 Map of expected levels of shaking from future earthquakes based on anticipated earthquakes and general geology. Bands of highest expected shaking generally follow the active faults; shaking levels are also influenced by the type of materials underlying an area - soft sediment, like that around the Bay margin, tends to amplify and prolong shaking. Note that much of the Bay region has the potential to be shaken very strongly during future earthquakes. Figure modified from U.S. Geological Survey, General Information Product 15, 2005 and, in turn, from
http://www.consrv.ca.gov/cgs/rghm/psha/index.htm
Map of expected levels of shaking

41 San Andreas Fault

42 Ground motion (10% probability of being exceeded in 50 years) in fraction of g

43 Exploratory Boring B-1

Dated drilling: 2/21/2024 Boring: B-1 Figure No.

Project Name: 1392 - Ngai

Laurel Glen Ave.

Palo Alto
Lot 13
Logged by: Farshad

SOIL DESCRIPTION
Boring Log Depth in Feet Sampler Number Penetration Resist. Blows/Foot U.S.C.S. Soil -group Moisture Content (%) Dry Density P.C.F.

Topsoil 12”- vegetated mixed yell, grey,
brown, sandy silty clay with some gravel,
damp, hard
-12” to 24”- Hard, dark yellowish brown,
sandy silty clay, moist, firm,
2’ to 5’ - yellow, weathered bed rock,
sand/siltstone at, SPT 20/30/46

Continued drilling to 8 ft. no changing.

At 8’ weathered rock, sand/siltstone
Stopped drilling at 8 ft.
- No water encountered.

----------------------
At depth to2ft
-PI=21.4, Effective stress envelope ϕ’ =33o
Gravel G=1.5%, Sand S=26%, Fine F=72.5%
-CL inorganic silty clay, with low plasticity.
-weathered rock, sand/siltstone
-Dry unit weight ϒdry =120 PCF, ϒtotal=136
PCF, Optimum moisture Wopt=13%.

1 2

4 5

7 9

14 17

76 CL

17 18

120

110

44 Exploratory Boring B-2

Dated drilling: 2/21/2024 Boring: B-2 Figure No.

Project Name: 1392 - Ngai

Laurel Glen Ave.

Palo Alto
Lot 13
Logged by: Farshad

SOIL DESCRIPTION
Boring Log Depth in Feet Sampler Number Penetration Resist. Blows/Foot U.S.C.S. Soil -group Moisture Content (%) Dry Density P.C.F.

Topsoil 0” to 24”- vegetated mixed dark
grayey brown, sandy silty clay with some
gravel, moist, Firm

-2’ to 5”- Hard, yellowish brown, sandy silty
clay, moist, hard. SPT 5/7/12.

5’ to 10’ - yellowish brown, at 5’ weathered
rock, sand/siltstone, SPT 10/12/20

10’ to 15’ - yellowish brown, at 12’ hit
weathered rock, sand/siltstone, SPT 16/20/30

15’ to 20’ - brownish yellow, weathered
rock, sand/siltstone, SPT 30/32/35

Stopped drilling at 20 ft.
- No water encountered.

- Effective stress envelope ϕ’ =33o
-weathered rock, siltstone
-Dry unit weight ϒdry =120 PCF, ϒtotal=136
PCF, Optimum moisture Wopt=18%.

1 2

4 5

7 10

15 19

32 CL

16 18

120

45 Exploratory Boring B-3

Dated drilling: 4/29/2024 Boring: B-3 Figure No.

Project Name: 1392 - Ngai

Laurel Glen Ave.

Palo Alto
Lot 13
Logged by: Farshad

SOIL DESCRIPTION
Boring Log Depth in Feet Sampler Number Penetration Resist. Blows/Foot U.S.C.S. Soil -group Moisture Content (%) Dry Density P.C.F.

Topsoil 0” to 24”- dark brown, sandy silty
clay, very moist, medium stiff, SPT 4/5/7
-2’ to 6’- yellowish brown, sandy silty clay,
moist, firm, SPT 5/7/13.

-6’ to 10’, brownish yellow, silty clayey
sand, very moist, SPT 9/15/21.

10’ to 15’, yellowish brown, sandy silty clay,
moist, encountered weathered rock at 12 ft
SPT 34/43/50 for 5”.

Stopped drilling at 15ft.
- No water encountered.

----------------------
At depth to3ft
-LL=41.3, PL=21.8, PI=19.5.

Effective stress envelope ϕ’ =33o
Gravel G=1%, Sand S=51%, Fine F=48%
-SC-SM inorganic silty clayey sand.
-weathered rock, sand/siltstone below 12 ft.
-Dry unit weight ϒdry =120 PCF, ϒtotal=136
PCF, Optimum moisture Wopt=13%.

2 6

8 10

15 12
20 36

SM
-SC

21 22

18 110

110

46 Exploratory Boring B-4

Dated drilling: 4/29/2024 Boring: B-4 Figure No.

Project Name: 1392 - Ngai

Laurel Glen Ave.

Palo Alto
Lot 13
Logged by: Farshad

SOIL DESCRIPTION
Boring Log Depth in Feet Sampler Number Penetration Resist. Blows/Foot U.S.C.S. Soil -group Moisture Content (%) Dry Density P.C.F. -Topsoil 0” to 24”, vegetated, dark brown,
silty clayey sand, very moist, stiff,
SPT 5/7/10.
-2’ to 6’, yellowish brown, silty clayey sand,
very moist, firm, SPT 10/17/20.

-6’ to 10’, brownish yellow, silty clayey,
sand, very moist, SPT 29/40/60.

-10’ to 15’, yellowish brown, sandy silty
clay, moist, encountered weathered rock at
10 ft SPT 34/43/50 for 5”.

-Stopped drilling at 15 ft.
- No water encountered.

At depth 3ft
-LL=41.3, PL=21.8, PI=19.5.

Effective stress envelope ϕ’ =33o
Gravel G=1%, Sand S=62%, Fine F=37%
-SC-SM inorganic silty clayey sand.
-weathered rock, sand/siltstone below 10 ft.
-Dry unit weight ϒdry =120 PCF, ϒtotal=136
PCF, Optimum moisture Wopt=13%.

2 6

10 15

14 17

17 37

100

43/50
for 5”

SC-
SM

28 22

15 110

110

47 MAJOR DIVISIONS
GROUP

SYMBOLS

SOIL DESCRIPTION

COARSE

GRAINED

SOILS

More than half
material is larger
than # 200 sieve

GRAVELS

(More than 50 %
material larger
than # 4 sieve)

CLEAN GRAVEL
Less than 5%fines
GW Well Graded Gravels, Gravel-Sand Mixtures, little or Fines
GP Poorly Graded Gravels or Gravel-
Sand Mixtures, little or No Fines
GRAVEL
With Fines
(More than 12% fines)

GM Silt, Gravels, Gravel-Sand-Silt Mixtures, Non-Plastic Fines
GC

Clayey Gravels, Gravel-Sand-Clay
Mixtures, Plastic Fines
SANDS

(More than 50 %
material smaller
than # 4 sieve)

CLEAN SAND
(Less than 5% fines)
SW Well Graded Sands, Gravelly Sands, Little or No
Fines.

SP Poorly Graded Sands or Gravelly Sands, Little or No
Fines.

SAND
With Fines (More than 12%
fines)
SM Salty Sands, Sand-Silt Mixtures, Non-Plastic Fines
SC Clayey Sands, Sand-Clay Mixtures, Plastic Fines.

FINE

GRAINED
SOILS
More than half
material is smaller
than the #200 sieve

SILTS & CLAYS
Liquid Limit is less than 50%

ML Inorganic Silts, Sandy or Clayey Silts,
Low to no Plasticity
CL Inorganic Clay, Sandy or Silty Clay, Low to Medium
Plasticity
OL Organic Silt or Organic Silty Clay, Low to Medium
Plasticity

SILTS & CLAYS
Liquid limit is greater than 50%

MH Inorganic Silts, Diatomaceous or Micaceous, Fine
Sandy or Silty Soils
CH Inorganic Clays of High Plasticity, Fat Clays
OH Organic Clays of Medium to High Plasticity, Organic
Silts
HIGHLY ORGANIC SOILS PT Peat and Other Highly Organic Soils

PARTICLE SIZE LIMITS
(Sieve Openings in mm.) .074 .425 2.00 4.17 19.0 75.0 300.0

SILT OR CLAY

SAND

GRAVEL

COBBLES BOULDERS

FINE MEDIUM COARSE FINE COARSE
(U.S. Standard sieve Sizes) # 200 # 40 # 10 # 4 .75 in 3 in 12 in

RELATIVE DENSITY CONSISTENCY

SANDS, GRAVELS AND

NON-PLASTIC SILTS
BLOWS/FOOT* CLAYS AND

PLASTIC SILTS
STRENGTH + BLOWS /
FOOT *

VERY LOOSE
LOOSE

MEDIUM DENSE

VERY DENSE
0 - 4
4 - 8
8 - 16
16 - 32
OVER 32

VERY SOFT
SOFT

MEDIUM STIFF
STIFF

VERY STIFF
HARD
0 - 1/ 4
1/4 - 1/2
1/2 - 1
1 - 2
2 - 4
OVER 4
0 – 2
2 – 4
4 – 8
8 – 16
16 – 32
OVER 32
* Numbers of blows of 140 pound hammer falling 30 inches to drive a 2-inch O.D. (1 – 3 / 8 inch I. D.) split spoon (ASTM D -1586). + Unconfined compressive strength in tons/sq. ft. as determined by laboratory testing or approximated by the Standard Penetration test (ASTM D – 1586), pocket penetrate meter, turbaned or visual observation.

Key to Exploratory Boring Logs

DMG Engineering, Inc.
30 Oakvue Court, Pleasant Hill, CA 94523
Phone: 925-787-0463 Fax: 925-287-8503
January 14, 2026
City of Palo Alto ARB
250 Hamilton A venue
Palo Alto, CA 94301
Reference: Story Pole Certification - 929 Laurel Glen Drive, Palo Alto This letter is to certify that on January 14, 2026, DMG Engineering, Inc. verified that the story poles conformed to the architectural drawings prepared by VRCHITECTS, revision dated 7/30/2025, with a print date of 1/7/2026.

If you have any further questions regarding this matter, please contact me at your convenience.

Sincerely,
Dylan onsalves, PE, PLS
ANO

DYLAN M
GONSALVES :JJ
\ (.f> PLS 84 75
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'-. f: CA\..\
City of Palo Alto
Fire Department

250 Hamilton Avenue 6th Floor, Palo Alto CA 94301
Ph: (650) 329-2184 / Fax: (650) 327-6951 [email protected] 10/22/2025

Greetings Zoltan,
The Palo Alto Fire Department conducted a flow test for 929 Laurel Glen Drive on 10/3/25.

The flow test results:

Static- 80psi
Residual- 45psi
Pitot- 30psi
Diameter-2.5
Hydrant Flowing 919gpm

Please confirm with our Fire Plans Examiners that this data is acceptable for your project.

Respectfully,

Shannon Ford
Administrative Associate

Palo Alto City CouncilJune 15, 2026

Palo Alto City Council
June 15, 2026