Palo Alto City Council
January 23, 2023

Methodology
This BRCA includes a review of relevant literature followed by a reconnaissance-level field survey and aquatic resources delineation. The purpose of this BRCA is to document the biological conditions of the project site and to provide information on the potential constrains to development related to sensitive biological resources.

Literature Review
Information on biological resources was compiled from a variety of publicly available sources including:
▪ Aerial photographs of the project site and vicinity;
▪ California Department of Fish and Wildlife (CDFW) California Natural Diversity Database (CNDDB; CDFW 2021a);
▪ California Native Plant Society (CNPS) Inventory of Rare and Endangered Plants (CNPS 2021); ▪ CDFW Biogeographic Information and Observation System (BIOS; CDFW 2021b); ▪ CDFW Special Animals List (CDFW 2021c);
▪ CDFW Special Vascular Plants, Bryophytes, and Lichens List (CDFW 2021d); ▪ U.S. Fish and Wildlife Service (USFWS) Information for Planning and Consultation System (IPaC; USFWS 2021a);
▪ USFWS Critical Habitat Portal (USFWS 2021b);
▪ USFWS National Wetlands Inventory (NWI; USFWS 2021c); ▪ USGS National Hydrography Dataset (NHD; USGS 2021);
▪ NOAA Fisheries California Species Tool (National Oceanic and Atmospheric Administration [NOAA] 2021)
▪ Essential California Habitat Connectivity Project data (available as GIS layers in BIOS [CDFW 2021b]).

In addition, the Technical Memorandum Biotic Study (2014) prepared by Wildlife Research Associates (WRA) for an adjacent site was reviewed. The sources outlined above provide general information and coarse-grained data on biological resources to support a preliminary desktop assessment of the biological conditions of the project site. This level of evaluation allows for an assessment of potential constraints to development from sensitive biological resources and is sufficient to support CEQA environmental review. The potential presence of special-status species is based on the literature review which is intended to assess general habitat suitability within the project site only.

Field Reconnaissance Survey
Rincon Biologist Christian Knowlton conducted a field reconnaissance survey on October 5, 2021. Mr.

Knowlton surveyed the entire project site on foot and recorded all biological resources encountered on site. Weather conditions at the time of the survey were clear (0% cloud cover) with winds at approximately zero to three miles per hour (mph) and an air temperature of 61 degrees Fahrenheit (F).

The survey was conducted to document the existing site conditions, map vegetation communities, and to evaluate the potential for presence of sensitive biological resources, including sensitive plant and animal species, sensitive plant communities, and habitat for nesting birds protected by federal and state laws. During the survey, an inventory of all plant and animal species observed was compiled.

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All plant species encountered were noted and identified to the lowest taxonomic level possible given the condition of the materials during the site visit. Plant species nomenclature and taxonomy followed Baldwin et al. (2012) as updated by The Jepson Online Interchange (University of California, Berkeley 2020). (Jepson Flora Project 2021). The vegetation classification system used for this analysis is based on A Manual of California Vegetation, Second Edition (MCV2; Sawyer et al. 2009), but has been modified as needed to accurately describe the existing habitats observed on site. Vegetation communities were mapped onto aerial imagery depicting the project site and then later digitized using ArcGIS® (ESRI 2021).

Wildlife identification and nomenclature followed standard reference texts, including Sibley Birds West:

Field Guide to Birds of Western North America (Sibley 2016). The habitat requirements for each regionally occurring special-status species were assessed and compared to the type and quality of the habitats observed within the project site during the field survey. Several sensitive species were eliminated from consideration as having potential to occur on site due to lack of suitable habitat, lack of suitable soils/substrate, and/or knowledge of regional distribution.

Existing Conditions
Topography and Soils
Topography of the site is relatively flat, with elevation approximately 535 feet (163 meters) above mean sea level. A review of the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service’s online Web Soil Survey (2019) revealed one soil type mapped within the site: Flaskan sandy clay loam, 5 to 9 percent slopes. The Flaskan series consists of very deep, well drained soils that formed in alluvium from mixed rock sources. (USDA 2021b)
Vegetation Communities and General Land Cover Types
Three terrestrial vegetation communities or other land cover types were observed within the project site. A map approximating the types and acreages of the various vegetation communities and land-cover types that occur within the study area is shown in Attachment 1 (Figure 2). Habitat characterizations were based on the classification systems presented in MCV2 (Sawyer et al. 2009); but have been modified slightly to reflect the existing site conditions most accurately. See Attachment 3 for a complete list of plant species observed within the project site.

Coast Live Oak Woodland
Coast live oak woodland (Quercus agrifolia Forest and Woodland Alliance) is typically found on canyon bottoms, slopes, and flats with deep sandy or loamy soils throughout the inner and outer Coast Ranges, Transverse Ranges, and southern coast, usually below 1,200 meters. Coast live oak woodlands are widely distributed throughout the state from northern Mendocino County to San Diego County. This community is dominated by coast live oak (Q. agrifolia), often including California bay (Umbellularia californica) and Pacific madrone (Arbutus menziesii). Stands vary from open or continuous to savanna- like. Dense conditions support sparse understory vegetation including California blackberry (Rubus ursinus), poison oak, and snowberry (Symphoricarpos spp.), while more open stands have a grassy understory (Sawyer et al. 2009; Holland 1986).

Coast live oak woodland is found throughout the project site. Canopy cover is continuous to scattered, with a moderately dense understory of herbs and shrubs. Other observed tree species commonly ITEM 13
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associated with coast live oak woodland include California bay and California buckeye (Aesculus californica). The shrub layer of the coast live oak woodland is typically poorly developed and the herbaceous layer is mostly continuous with adjacent grasslands. Shrubs in the project site include poison oak, coyote brush, and California blackberry.

Non-native annual grassland
Non-native annual grassland is typically comprised of annual grasses and forbs introduced during and since the Spanish colonial period. This vegetation community most closely resembles the Avena spp. – Bromus spp. Herbaceous Semi-Natural Alliance described by Sawyer et al. (2009). Non-native annual grassland is generally found in open areas in valleys and foothills throughout coastal and interior California. It typically occurs on soils consisting of fine-textured loams or clays that are somewhat poorly drained. Non-native annual grasses and weedy annual and perennial forbs, primarily of Mediterranean origin, dominate this vegetation type, probably as a result of human disturbance. Scattered native grass and wildflower species, representing remnants of the original vegetation may also be common (Sawyer et al. 2009).

On the project site, this vegetation community primarily occurs in the interior of the site and is surrounded by coast live oak woodland. The majority of the non-native annual grassland within the project site had been previously mowed. Characteristic non-native annual grasses observed include wild oat (Avena fatua), Italian rye (Festuca perennis), and foxtail barley (Hordeum murinum). Many ruderal herbs were also present, including plantain (Plantago spp.).

Riparian
Riparian habitat is found along Los Trancos Creek within the project site. This habitat type is similar to coast live oak woodland described above, with the distinction that it occurs along the banks of the creek and is thus riparian habitat. The MCV has moved similar riparian woodlands into the California sycamore – coast live oak riparian woodlands (Platanus racemosa – Quercus agrifolia Woodland) alliance, but this vegetation community does not include California sycamore, and the vegetation community present best corresponds to the Central Coast live oak riparian forest as described in Holland (1986). This plant community would be classified as upland where trees are rooted outside of the top of banks at the drainages and as palustrine forested wetland where trees are rooted along the drainage banks, following Cowardin et al. (1979).

General Wildlife
Wildlife activity was low during the reconnaissance survey. Eastern gray squirrel (Sciurus carolinensis), Nuttall’s woodpecker (Dryobates nuttallii), and Steller’s jay (Cyanocitta stelleri) were observed at the project site during the site survey. See Attachment 4 for a complete list of wildlife species observed within the project site.

Biological Constraints
Special-Status Species
For the purpose of this report, special status species are defined as those plants and animals listed, proposed for listing, or candidates for listing as threatened or endangered by the USFWS or NMFS under ITEM 13
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the FESA; those listed or candidates for listing as rare, threatened, or endangered by the CDFW under CESA; animals designated as “Species of Special Concern” (SSC) by the CDFW or “Fully Protected” under the CFGC; and plants with a California Rare Plant Rank (CRPR) of 1B, 2, 3, or 4.

The project site may contain suitable habitat for special-status species. Based on the agency databases and literature review, as well as the results of the reconnaissance survey of the project site, Rincon evaluated 85 special-status species (40 special-status plant species and 45 special-status animal species) documented within the Mindego Hill, California USGS 7.5-minute topographic quadrangle and the surrounding eight quadrangles (Woodside, Palo Alto, Mountain View, La Honda, Cupertino, Franklin Point, Big Basin, and Castle Rock Ridge). Each of these 85 species was evaluated for its potential to occur in the project site (see Attachment 5). The majority of special-status species are not expected to occur based on the absence of suitable habitat and/or the project site being outside of the geographic range of the species.

Special-Status Plants
As noted above, based on the database and literature review of records, 40 special-status plant species are known to or have the potential to occur within the regional vicinity of the project site (Attachment 4). Potential to occur within the project site was based primarily on the presence of suitable habitat, determined during the site reconnaissance survey, and the proximity to CNDDB/CNPS documented occurrences. No special-status plant species were detected within the project site during the reconnaissance survey; however, this survey was conducted outside of the seasonal bloom period for many special-status plant species and the project site had been recently mowed. As such, it is possible that these special-status plant species occur at the project site but were simply undetected due to the timing of the reconnaissance survey and problematic vegetation conditions due to regular vegetation maintenance.

Of the 40 special-status plant species, one has a moderate potential to occur on the project site.

Woodland woollythreads (Monolopia gracilens), CRPR 1B.2, can be found in a variety of habitat types, including some that occur on the project site, such as woodlands and grassy sites in openings. Blooming period for this species is March through July. Multiple occurrences of woodland woollythreads have been recorded within five miles of the project area, including the most recent occurrence from 2018 approximately one mile southwest of the project site. Protections are afforded for this and other special-status plants through CEQA, regardless of their listing status under the FESA, CESA, or the Native Plant Protection Act (NPPA).

Special-Status Animals
Forty-five special-status animal species were reported to occur within the regional vicinity, based on the database and literature review. Habitats within the project site have moderate to high potential to support nine special-status wildlife species: steelhead - central California coast (CCC) distinct population segment (steelhead) (Oncorhynchus mykiss irideus), Santa Cruz black salamander (Aneides niger), California giant salamander (Dicamptodon ensatus), California red-legged frog (Rana draytonii), western pond turtle (Emys marmorata), San Francisco gartersnake (Thamnophis sirtalis tetrataenia) pallid bat (Antrozous pallidus), Townsend’s big-eared bat (Corynorhinus townsendii), and San Francisco dusky- footed woodrat (Neotoma fuscipes annectens). Each of these species is discussed in more detail below.

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Steelhead
The project site is located within the known range of the federally listed as threatened steelhead.

Steelhead that occur in this geographic area are considered part of the CCC DPS. This DPS was listed by NMFS in 2006 and includes steelhead populations in streams from the upper Russian River in Mendocino County to Aptos Creek in southern Santa Cruz County (NMFS 2016).

Steelhead are capable of surviving in a wide range of temperature conditions within freshwater and estuarine environments but prefer temperatures less than 57 degrees Fahrenheit. Eggs tend to experience mortality at temperatures greater than 55 degrees Fahrenheit, and steelhead appear to have difficulty obtaining sufficient oxygen from water temperatures greater than 70 degrees Fahrenheit.

Elevated summer water temperatures have been identified as a problem (CDFW 1996). Steelhead do best where dissolved oxygen concentrations are at least seven parts per million. In streams, deep low- velocity pools are important wintering habitats. Spawning habitat consists of gravel substrates that are free of excessive silt.

Los Trancos Creek runs along the property boundary on the western side. It is immediately adjacent to the project site and is critical habitat for steelhead. A 20-foot creek setback is marked on the proposed project plan, indicating that the creek is outside the limits of disturbance. Implementation of the proposed project may result in direct or indirect impacts to steelhead at all life stages. The results and conclusions presented herein represent our best professional judgement but do not represent determinations of the NMFS and CDFW as these agencies have ultimate jurisdiction over the steelhead through administration and enforcement of the FESA and CESA, respectively.

Santa Cruz black salamander
Santa Cruz black salamander (Aneides flavipunctatus niger) is a state species of special concern. This species is typically found in mixed deciduous woodlands, coniferous forests, and coastal grasslands in Santa Cruz, Santa Clara, and San Mateo counties. They primarily reside in moist habitats with wet soils, rotten logs, and surface debris for cover adjacent to ravines and water courses below 3,500 feet in elevation (Zeiner 1990, CDFW 2021a, Nafis 2020).

Los Trancos Creek and the riparian corridor within the project site provides suitable breeding and foraging habitat for Santa Cruz black salamander. The grassland and oak woodland within the project site may also be utilized by dispersing salamanders. Implementation of the proposed project may result in direct or indirect impacts to individuals within the project site.

California giant salamander
California giant salamander (Dicamptodon ensatus) is a state species of special concern that occurs in damp coastal forests and riparian woodland habitats up to 6,500 feet in elevation. Terrestrial adults are commonly found in damp litter, in burrows, or under fallen logs, and aquatic adults typically occur near cold, clear, permanent or semi-permanent water sources with rocky substrates. Breeding occurs from March to May and eggs are laid in slow moving waters and springs and under streambanks (Zeiner 1990, CDFW 2021a, Nafis 2020).

Los Trancos Creek and the riparian corridor within the project site provides suitable breeding and foraging habitat for California giant salamander. The grassland and oak woodland within the project site may also provide habitat for burrowing animals which may provide refugia for California giant ITEM 13
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salamander. Implementation of the proposed project may result in direct or indirect impacts to individuals within the project site.

California red-legged frog
The California red-legged frog is federally listed as threatened and a state species of special concern throughout its range. The historic range of California red-legged frog extended along the coast from the vicinity of Point Reyes National Seashore, Marin County, and inland from the vicinity of Redding, Shasta County, southward to northwestern Baja California, Mexico. California red-legged frog inhabits quiet pools of streams, marshes, and ponds. All life history stages are most likely to be encountered in and around breeding sites, which include coastal lagoons, marshes, springs, permanent and semi-permanent natural ponds, and ponded and backwater portions of streams, as well as artificial impoundments such as stock ponds, irrigation ponds, and siltation ponds. Eggs are typically deposited in permanent pools, attached to emergent vegetation (USFWS 2011).

Los Trancos Creek and the riparian corridor within the project site may provide suitable breeding habitat, in slow moving pools, and foraging habitat for California red-legged frog. The closest documented breeding habitat is approximately 2.6 miles north of the project site within San Francisquito Creek. The grassland and oak woodland within the project site may also provide habitat for burrowing animals which may provide refugia for California red-legged frog. Implementation of the proposed project may result in direct or indirect impacts to individuals within the project site.

Western pond turtle
Western pond turtle (Actinemys marmorata [=Emys marmorata]) is a state species of special concern.

This species is a semi-aquatic turtle that occurs in ponds, marshes, rivers, streams and irrigation ditches that typically support aquatic vegetation. It requires downed logs, rocks, mats of vegetation, or exposed banks for basking. Western pond turtle lay their eggs in nests dug along the banks of streams or other uplands in sandy, friable soils. Western pond turtles, especially those that reside near creeks, are known to overwinter in upland habitats. Upland movements can be quite extensive, and individuals have been recorded nesting or overwintering hundreds of meters from aquatic habitats. The typical nesting season is usually from April through August; however, variation exists depending upon geographic location.

Los Trancos creek may provide suitable foraging habitat for the western pond turtle. The oak woodland and annual grassland may also provide suitable breeding and foraging habitat. Western pond turtles have been documented approximately 2.9 miles north of the project site within San Francisquito Creek.

Implementation of the proposed project may result in direct or indirect impacts to individuals within the project site.

San Francisco garter snake
San Francisco garter snake (Thamnophis sirtalis tetrataenia) is federally and state listed as endangered.

The historical distribution of the San Francisco garter snake included wetland areas on the San Francisco peninsula from the San Francisco County line south along the eastern and western foothills of the Santa Cruz Mountains to at least Upper Crystal Springs Reservoir and Año Nuevo Point in San Mateo County, and Waddell Creek in Santa Cruz County. The San Francisco garter snake occurs in a number of aquatic and terrestrial habitats throughout their range.

San Francisco garter snake has been documented within the San Francisquito Creek watershed, which Los Trancos Creek is a part of. Suitable aquatic and terrestrial habitats are found along Los Trancos ITEM 13
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creek. Implementation of the proposed project may result in direct or indirect impacts to individuals within the project site.

Special-Status Bat Species
Pallid bat, and Townsend’s big-eared bat are CDFW SSC. Pallid bats are found in grasslands, shrublands, woodlands, and forests, and may roost in trees or buildings. Townsend’s big-eared bat are found in a wide variety of habitats and may roost in abandoned buildings or large trees. Bats prefer open areas or open areas under a tree canopy for foraging, and often roost near water. Several large and mature oak trees contain dense canopy cover within the project site may provide suitable roosting habitat for these special-status bat species. Implementation of the proposed project may result in direct or indirect effects to roosting special-status bat species, should they be present within the project site and/or immediate surrounding vicinity.

San Francisco dusky-footed woodrat
The San Francisco woodrat is one of eleven described subspecies of the dusky-footed woodrat (Hooper 1938) and is recognized by the CDFW as a species of special concern. Dusky-footed woodrats are well known for their large terrestrial stick houses/nests, some of which can last for twenty or more years (Linsdale and Tevis 1951). Middens/nests can be placed on the ground against or straddling a log or exposed roots of a standing tree and are often located in dense brush. Middens/nests are also placed in the crotches and cavities of trees and in hollow logs. Sometimes arboreal nests are constructed, this behavior seems to be more common in habitat with evergreen trees such as live oak. The body coloring is brown/grey with white/grey underside and white/dusky coloring on feet. The woodrats have a hairy brown tail, usually with a lighter underside, and large ears (Burt and Gossenheider 1980). The San Francisco dusky-footed woodrat can be found throughout the San Francisco Bay area in grasslands, scrub and wooded areas (Hall 1981).

Several San Francisco dusky-footed woodrat nests were observed during the reconnaissance survey. The oak woodland provides suitable breeding and foraging habitat throughout the project site.

Implementation of the proposed project may result in direct or indirect impacts to individuals within the project site.

Nesting Birds
The California Fish and Game Code (CFGC) Section 3503 and the federal Migratory Bird Treaty Act (MBTA) protect native bird species and their nests. The blue oak woodland habitat within and adjacent to the project site provides suitable nesting habitat for a variety of bird species. No active or inactive bird nests were observed within the project site during the reconnaissance-level field surveys. However, species of birds that typically occur in the region, such as red-shoulder hawk (Buteo lineatus), Steller’s jay, and Anna’s hummingbird (Calypte anna), may nest in the project site or surrounding area.

Implementation of the proposed project may result in direct or indirect effects to nesting bird species, should they be present within the project site and/or immediate surrounding vicinity.

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Special-Status Vegetation Communities and Critical Habitat Sensitive Natural Communities
Plant communities are also considered sensitive biological resources if they have limited distributions, have high wildlife value, include sensitive species, or are particularly susceptible to disturbance. The CDFW ranks sensitive communities as “threatened” or “very threatened” and keeps records of their occurrences in CNDDB. CNDDB vegetation alliances are ranked 1 through 5 based on NatureServe’s (2010) methodology, with those alliances ranked globally (G) or statewide (S) as 1 through 3 considered sensitive. Some alliances with the rank of 4 and 5 have also been included in the 2020 sensitive natural communities list under CDFW’s revised ranking methodology (CDFW 2020). Three sensitive natural communities are known to occur within the nine-quadrangle search radius, none of which are present within the project site:
▪ Northern Coastal Salt Marsh
▪ Serpentine Bunch Grass
▪ Valley Oak Woodland
Critical Habitat
Critical habitat for steelhead is present in Los Trancos Creek, shown in Appendix A (Figure 2), both within and immediately adjacent to the project site. (NOAA 2021). Designated critical habitat is also located in several of the rivers surrounding the project site within five miles for coho Salmon (Central California Coast ESU; Oncorhynchus kisutch pop. 4). However, the project site does not overlap with these rivers and no drainages onsite are connected to the rivers where critical habitat is designated. Designated critical habitat for California red-legged frog and Bay checkerspot butterfly (Euphydryas editha bayensis) is located within five miles of the project area (USFWS 2021b); however, the project does not overlap with either of these designated critical habitats.

Oak Trees
Coast live oak trees and valley oak trees with a diameter at breast height of greater than 11.5 inches occur within project site. Pursuant to Section 8.10, Tree Preservation and Management Regulations, of the Palo Alto Municipal Code, these on-site oak trees would qualify as protected trees. Under Section

8.10.020, all protected trees that are planned for removal must be approved by the director of planning and development services, on the basis of a tree report prepared by a certified arborist. The proposed project may result in trimming and or disturbance close in proximity to several of the trees and may include work within oak tree driplines. As such, implementation of the proposed project may result in direct or indirect impacts to protected oak trees within the project site.

Jurisdictional Waters and Wetlands
Los Trancos Creek is an intermittent stream within and immediately adjacent to the project site and is potentially under the jurisdiction of the U.S. Army Corps of Engineers (USACE), CDFW, and/or Regional Water Quality Control Board (RWQCB). Riparian habitat (coast live oak woodland) occurs adjacent to the creek. Coast live oak woodland is not a CDFW sensitive natural community, but riparian habitat is considered to be a jurisdictional wetland by CDFW. Project plans appear to avoid impacts to Los Trancos ITEM 13
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Creek, however the proposed project may result in indirect impacts to the creek and direct or indirect impacts to riparian habitat if project activities occur within the dripline of the riparian canopy.

Discussion and Recommendations
The project site contains: potentially suitable habitat for one special-status plant species, nine special- status wildlife species and nesting bird species; native oak trees; and potentially jurisdictional areas. If the project will be subject to environmental review under CEQA and there will be impacts to special- status species that are not listed as threatened or endangered under CESA and/or FESA, it may be considered significant and compensatory mitigation and/or specific avoidance and minimization measures may be required before and during construction of the project.

Special-Status Plant Species
The project site contains suitable habitat for one special-status plant species, as described above. It was not observed within the project site during the reconnaissance survey; however, the reconnaissance survey was conducted outside the bloom period for the species. Following are recommendations to address constraints due to the potential presence of special-status plants within the project site:
▪ A qualified biologist should conduct a protocol level botanical survey, including a site visit during the blooming period in March through July, and to ensure impacts to special-status plant species are avoided, minimized, and/or mitigated.
▪ If the CRPR 1 rank plant is found, a qualified biologist shall determine if the project will result in a significant impact and if so, prepare compensatory mitigation measures.

Special-Status Wildlife Species
The project site contains suitable habitat for nine special-status wildlife species. Los Trancos Creek is designated critical habitat for steelhead, and the non-native annual grassland in the woodland openings may provide suitable habitat for several other species. The large and mature oak trees on the project site provide potentially suitable habitat for nesting birds as well as special-status bat species. None of these species were observed onsite during the reconnaissance-level field surveys and no focused or protocol-level species surveys were conducted. Following are recommendations to address constraints due to the potential for occurrence of special-status wildlife and the presence of their habitats within the project site:

Steelhead:

Best management practices (BMPs) should be implemented during all construction activities that take place in or adjacent to Los Trancos Creek to prevent erosion and sedimentation into the creek and to prevent the spill of contaminants in or around the creek. Construction should occur between June and December, outside of steelhead migration season in the region.

The following BMPs should be implemented on-site during construction to prevent any indirect impacts to waters and wetlands:
▪ Vehicles and equipment should be checked at least daily for leaks and maintained in good working order. Spill kits should be available on-site at all times and a spill response plan should be developed and implemented.

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▪ Sediment and erosion control measures (e.g., sand or gravel bags, hay bales, check dams) should be implemented and maintained throughout the project site to prevent the entry of sediment and/or pollutants into any waterways or jurisdictional areas. No monofilament plastic will be used for erosion control.

California Giant Salamander and Santa Cruz Black Salamander Immediately prior to initial ground disturbance and vegetation removal, a qualified biologist shall conduct a preconstruction clearance survey of the site for special status amphibians. If California giant salamander and/or Santa Cruz black salamander are observed on site, they shall be relocated to suitable habitat in the immediate vicinity by the qualified biologist. The following additional measures shall be implemented to reduce potential impacts:
▪ Vegetation disturbance shall be the minimum necessary to achieve the goals of the project. ▪ All trash shall be removed from the site daily and disposed of properly to avoid attracting potential predators to the site.
▪ No pets shall be permitted on site during project activities. ▪ All vehicles shall be in good working condition and free of leaks. All leaks shall be contained and cleaned up immediately to reduce the potential of soil/vegetation contamination. ▪ All hole and trenches shall be covered at the end of the day or ramped to avoid entrapment.

California red-legged frog:

A qualified biologist shall conduct a pre-construction survey within 14 days prior to initiation of construction activities. The USFWS will be notified should California red-legged frog be observed within the project site. The following avoidance and mitigation measures should be implemented to avoid impacts to California red-legged frog:
▪ Construction crew shall be taught during the WEAP training to check beneath the staging equipment each morning prior to commencement of daily construction activities. Should California red-legged frog occur within the staging areas, construction activities shall be halted until the California red- legged frog vacates the project site on its own or until a biologist with a USFWS Recovery Permit for California red-legged frog relocates the California red-legged frog. ▪ Prior to ground disturbance a temporary wildlife exclusion barrier shall be installed along the limits of disturbance. A qualified biologist will inspect the area prior to barrier installation. The barrier will be designed to prevent California red-legged frog from entering the project area, and will remain in place until all development activities have been completed. This barrier will be inspected daily by a qualified biologist and maintained and repaired as necessary to ensure that it is functional and is not a hazard to California red-legged frogs or San Francisco garter snakes on the outer side of the barrier.
▪ A qualified biologist shall be present during all grading and initial ground disturbing activities. Should California red-legged frog be observed within the project site, the USFWS shall be notified and construction shall be halted until either the California red-legged frog exits the site on its own or until a biologist with a USFWS Recovery Permit for California red-legged frog relocates the California red-legged frog.

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▪ No work should occur during a rain event (over 0.25”). If a rain event occurs, a qualified biologist should inspect the site again prior to resuming work.

Western pond turtle
A qualified biologist shall conduct pre-construction clearance surveys for western pond turtle within 48 hours prior to the start of construction (including staging and mobilization) in areas of suitable habitat.

The biologist shall flag limits of disturbance for each construction phase. Areas of special biological concern within or adjacent to the limits of disturbance should have highly visible orange construction fencing installed by a contractor between said area and the limits of disturbance. If western pond turtles are observed they shall be allowed to leave the site on their own.

San Francisco garter snake
A qualified biologist shall conduct a focused pre-construction survey within 24 hours of the initiation of project activities. If San Francisco garter snake is found, the USFWS shall be notified immediately to determine the correct course of action and the proposed project shall not begin until approved by the USFWS.
▪ Construction personnel will participate in a worker environmental awareness program training. The training will cover the need to check beneath and around equipment each morning prior to commencement of daily construction activities. Should San Francisco garter snake occur within the project areas, construction activities shall be halted until the San Francisco garter snake vacates the project site on its own or until a biologist with a USFWS Recovery Permit for San Francisco garter snake relocates the snake.
▪ Vegetation will be cut to 6 inches in height or when the ground is visible, using hand tools (including string trimmers or chainsaw for brush). Once the ground is visible, a visual survey for San Francisco garter snake will be conducted by the biologist prior to additional ground disturbance. If San Francisco garter snake is found, USFWS will be notified immediate to determine the correct course of action.
▪ Prior to ground disturbance a temporary wildlife exclusion barrier shall be installed along the limits of disturbance. A qualified biologist will inspect the area prior to barrier installation. The barrier will be designed to prevent San Francisco garter snake from entering the project area and will remain in place until all development activities have been completed. This barrier will be inspected daily and maintained and repaired as necessary to ensure that it is functional and is not a hazard to California red-legged frogs or San Francisco garter snakes on the outer side of the barrier. ▪ Prior to conducting non-native plant removal or treatments (e.g., spraying with herbicide, cutting, pulling, digging out), the permittee shall make every reasonable attempt to ensure that SFGS are not hidden within the plant or residual plant matter to be treated.

Special-Status Bat Species:

There is suitable roosting habitat for special-status bats present in the large oak trees throughout the project site. Disturbance of maternity roosts from construction activities, resulting in roost destruction or abandonment, would be a potentially significant impact to special-status bat species and would be violations of CFGC. The following are recommendations and possible constraints due to special-status bat species within the project site:

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▪ Prior to tree removal, a qualified biologist should conduct a focused survey of all trees to be removed or impacted by construction activities to determine whether active roosts of special-status bats are present on site. If tree removal is planned for the fall, the survey should be conducted in September to ensure tree removal would have adequate time to occur during seasonal periods of bat activity, as described below. If tree removal is planned for the spring, then the survey should be conducted during the earliest possible time in March, to allow for suitable conditions for both the detection of bats and subsequent tree removal. Trees containing suitable potential bat roost habitat features should be clearly marked or identified.
▪ If day roosts are found to be potentially present, the biologist should prepare a site-specific roosting bat protection plan to be implemented by the contractor following the City of Palo Alto’s approval.

The plan should incorporate the following guidance as appropriate:
 When possible, removal of trees identified as suitable roosting habitat should be conducted during seasonal periods of bat activity, including the following:

1. Between September 1 and about October 15, or before evening temperatures fall below 45 degrees Fahrenheit and/or more than 0.5 inch of rainfall within 24 hours occurs.

2. Between March 1 and April 15, or after evening temperatures rise above 45 degrees Fahrenheit and/or no more than 0.5 inch of rainfall within 24 hours occurs.  If a tree must be removed during the breeding season and is identified as potentially containing a colonial maternity roost, then a qualified biologist should conduct acoustic emergence surveys or implement other appropriate methods to further evaluate if the roost is an active maternity roost. Under the biologist’s guidance, the contractor should implement measures similar to or better than the following:

1. If it is determined that the roost is not an active maternity roost, then the roost may be removed in accordance with the other requirements of this recommendation.

2. If it is found that an active maternity roost of a colonial roosting species is present, the roost should not be disturbed during the breeding season (April 15 to August 31).  Potential colonial hibernation roosts should only be removed during seasonal periods of bat activity. Potential non-colonial roosts that cannot be avoided should be removed on warm days in late morning to afternoon when any bats present are likely to be warm and able to fly.

Appropriate methods should be used to minimize the potential harm to bats during tree removal. Such methods may include using a two-step tree removal process. This method is conducted over two consecutive days and works by creating noise and vibration by cutting non- habitat branches and limbs from habitat trees using chainsaws only (no excavators or other heavy machinery) on day one. The noise and vibration disturbance, together with the visible alteration of the tree, is very effective in causing bats that emerge nightly to feed to not return to the roost that night. The remainder of the tree is removed on day two.

San Francisco dusky-footed woodrat
A qualified biologist should conduct a pre-construction survey for woodrats no more than 14 days prior to construction. Nests within 50 feet of project activity that would not be directly impacted by project activity should be demarcated with a 10-foot avoidance buffer and left intact. If a nest(s) that cannot be avoided are found during the pre-construction survey, an approved biologist should dismantle the nest and relocate it to suitable habitat outside the work area no more than 50 feet away with the goal of ensuring the individuals are allowed to leave the work area(s) unharmed before on site activities begin.

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reestablished. With the implementation of mitigation (worker training program and relocation of active nests), impacts to San Francisco dusky-footed woodrat would be reduced to less than significant.

Nesting Birds:

There is suitable nesting habitat for nesting birds throughout the project site. If construction activities are scheduled to occur during the avian nesting season (typically February 1 to September 15), then typical avoidance and minimization measures to prevent take of bird nests, eggs or nestlings under CFGC and the MBTA could pose constraints on the project. The following are recommendations and possible constraints due to special-status birds and nesting birds within the project site:
▪ A general pre-construction nesting bird survey should be conducted by a qualified biologist, within 14 days prior to the initiation of construction activities. If construction is stopped for more than 14 days during the nesting season, a pre-construction survey should be conducted prior to the re-start of construction activities. Surveys should include the disturbance area plus a 200-foot buffer for passerine species, and a 500-foot buffer for raptors.
▪ If active nests are located, an appropriate avoidance buffer should be established within which no work activity would be allowed which would impact these nests. The avoidance buffer would be established by the qualified biologist on a case-by-case basis based on the species and site conditions. Larger buffers may be required depending upon the status of the nest and the construction activities occurring in the vicinity of the nest. The buffer area(s) should be closed to all construction personnel and equipment until juveniles have fledged and/or the nest is inactive. A qualified biologist should confirm that breeding/nesting is complete, and the nest is no longer active prior to removal of the buffer. If work within a buffer area cannot be avoided, then a qualified biologist should be present to monitor all project activities that occur within the buffer. The biological monitor should evaluate the nesting avian species for signs of disturbance and should have the ability to stop work.

Protected Trees
Pursuant to Chapter 8.10 of the Palo Alto Municipal Code the on-site coast live oak and valley oak trees would qualify as protected trees. Depending on the extent of disturbance, the proposed project may result in trimming and or disturbance close in proximity to several of the trees within the project site.

Therefore, Section 8.10.050, Tree Preservation and Management Regulations would require an arborist report, conducted by a qualified arborist, tree mitigation may be required in accordance with the City of Palo Alto Tree Technical Manual. Additionally, should one or more protected trees be planned for removal, a tree protection and replacement plan may be required. This plan would include but is not limited to the following protective measures for trees:
▪ Prior to initiating any construction activity on a construction project, including demolition or grading, temporary protective fencing should be installed at each site tree.

1. Fencing should be located at the Tree Protection Zone (TPZ) illustrated on the Improvement Plans.

2. Fencing should serve as a barrier to prevent encroachment of any type by construction activities, equipment, materials storage, or personnel. ▪ The Tree Protection Zone (TPZ) is illustrated on the Improvement Plans and represents the area around each tree, or group of trees, which must be protected at all times with tree protection fencing.

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1. No encroachment into the TPZ is allowed at any time without approval from the project arborist.

2. Any unauthorized entry into the TPZ is a violation of the Tree Protection Ordinance and shall be subject to enforcement through civil, criminal or administrative remedies, including applicable penalties.
▪ Contractors and subcontractors should direct all equipment and personnel to remain outside the fenced area at all times until project is complete and should instruct personnel and sub-contractors as to the purpose and importance of fencing and preservation. ▪ No grade changes should be made within the protective barriers without prior approval by the Planning Director.
▪ No attachments or wires other than those of a protective or non-damaging nature should be attached to a protected tree.
▪ Excavation or landscape preparation within the protective barriers should be limited to the use of hand tools and small handheld power tools and should not be of a depth that could cause root damage.
▪ When the existing grade around a protected tree is to be raised the project and/or City arborist should provide written directions on which method(s) may be used to drain liquids away from the trunk.
▪ When the existing grade around a protected tree is to be lowered the project and/or City arborist should provide written directions on which method(s) may be used (terracing, retaining wall, etc.) to allow the dripline to be left at the original grade.
▪ No equipment, solvents, paint, asphalt, or debris of any kind should be placed, stored, or allowed within the protective barrier.

Potentially Jurisdictional Areas
Los Trancos Creek is within and adjacent to the project area. It is a tributary to San Francisquito Creek, which flows into San Francisco Bay, a Traditional Navigable Water, thus it is potentially under the jurisdiction of USACE, CDFW, and the Regional Water Quality Control Board (RWQCB). In addition, riparian habitat on the project site would be considered jurisdictional by CDFW and RWQCB. Therefore, the following avoidance and minimization measures are recommended:
▪ If the project will avoid impacts to the riparian area (shown on Figure 2), we recommend installing high visibility orange construction fence between the jurisdictional areas and the construction activities, including a 20-foot buffer setback, to avoid all potential impacts to jurisdictional areas. ▪ If the project will impact the riparian areas, a formal delineation report and map should be prepared. If wetland areas cannot be avoided, regulatory permits from USACE, CDFW, and RWQCB would be required prior to construction.
▪ Vehicles and equipment should be checked at least daily for leaks and maintained in good working order. Spill kits should be available on-site at all times and a spill response plan should be developed and implemented.
▪ Sediment and erosion control measures (e.g., straw wattles, silt fence, check dams) should be implemented and maintained throughout the project site to prevent the entry of sediment and/or pollutants into any waterways or jurisdictional areas. No monofilament plastic will be used for erosion control.

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Conclusion
As noted above, this report is intended to identify sensitive biological resources and potential occurrence of special-status species that represent potential constraints to development of the 575 Los Trancos Road project. This report provides analysis sufficient to support CEQA, though further analysis may be required for compliance with FESA, or CESA, and/or the CFGC. Thank you for the opportunity to support your environmental analysis needs for this important project. Please contact us if you have any questions.

Sincerely,
Rincon Consultants, Inc.

Christian Knowlton Sherri Miller
Biologist Principal

Attachments
Attachment 1 Figures
Attachment 2 Representative Site Photographs
Attachment 3 Plant Species List Observed
Attachment 4 Wildlife Species List Observed
Attachment 5 Special-Status Species Evaluation Tables
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References
Baldwin, B.G., D.H. Goldman, D.J. Keil, R. Patterson, T.J. Rosatti, and D.H. Wilken, editors. 2012. The Jepson Manual: Vascular Plants of California, second edition. University of California Press, Berkeley.

Burt, W.H., and R.P. Grossenheider. 1980. A Field Guide to the Mammals of North America North of Mexico. The Peterson Field Guide Series.

California Department of Fish and Wildlife (CDFW). 2020. California Sensitive Natural Communities Arranged Alphabetically by Life Form (PDF). Available from https://www.wildlife.ca.gov/Data/VegCAMP/Natural-Communities#sensitive%20natural %20communities (accessed October 2021).
____. 2021a. California Natural Diversity Database (CNDDB), Rarefind 5 (online). Commercial Version. (accessed October 2021).
____. 2021b. Biogeographic Information and Observation System (BIOS). http://bios.dfg.ca.gov (accessed October 2021).
____. 2021c. Special Animals List. July.
https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=109406&inline (accessed October 2021). ____. 2021d. Special Vascular Plants, Bryophytes, and Lichens List. July. https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=109383&inline (accessed October 2021). ____. 1996. Steelhead Restoration and Management Plan. Department of Fish and Game, Sacramento, California. February. https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=3490&inline.

California Native Plant Society (CNPS). 2021. Inventory of Rare and Endangered Plants of California (online edition, v9-01 0.0). https://www.rareplants.cnps.org (accessed October 2021).

Cowardin, L. M., V. Carter, F. C. Golet, and E. T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service. https://www.fws.gov/wetlands/documents/classwet/index.html#contents (accessed October 2021).

Hall, E. R. 1981. The Mammals of North America, Vol I, 2nd edition. John Wiley & Sons, New York. 690+92 pp.

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

California Department of Fish and Wildlife, Nongame Heritage Program. 156 pgs.

Hooper, E. T. 1938. Geographical variation in woodrats of the species Neotoma fuscipes. University of California Publications in Zoology 42:213-245.

Jepson Flora Project (eds.). 2021. Jepson eFlora, https://ucjeps.berkeley.edu/eflora/ Leidy, R.A., G.S. Becker, B.N. Harvey (2005). "Historical distribution and current status of steelhead/rainbow trout (Oncorhynchus mykiss) in streams of the San Francisco Estuary, California." Center for Ecosystem Management and Restoration, Oakland, California. Retrieved October 2021.

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Linsdale, J.M and L. P. Tevis. 1951. The Dusky-footed Wood Rat: A Record of Observations Made on the Hastings Natural History Reservation. University of California Press. Berkeley and Los Angeles. 664 pp.

Nafis, G. 2000-2020 California Herps - A Guide to the Amphibians and Reptiles of California.

Available at: http://www.californiaherps.com/ (accessed October 2021).

National Oceanic and Atmospheric Administration (NOAA). 2021. California Species List Tools. https://www.westcoast.fisheries.noaa.gov/maps_data/california_species_list_tools. html
National Marine Fisheries Service (NMFS). 2016. Final Coastal Multispecies Recovery Plan for California Coastal Chinook Salmon, Northern California Steelhead and Central California Coast Steelhead.

NMFS, Southwest Region, Santa Rosa, California.

Sawyer, J.O., T. Keeler-Wolf, and J.M. Evens. 2009. A Manual of California Vegetation, Second Edition.

California Native Plant Society, Sacramento, CA. 1300 pp.

Sibley. 2016. Sibley Birds West: Field Guide to Birds of Western North America. Knopf; second edition.

United States Department of Agricultural (USDA), Natural Resources Conservation Service (NRCS). 2019.

Web Soil Survey. July 31, 2019. Available at: http://websoilsurvey.nrcs.usda.gov/app/ (accessed October 2021).

U.S. Fish and Wildlife Service (USFWS). 2021a. Information, Planning, and Conservation Online Tool [online]. http://ecos.fws.gov/ipac/ (accessed October 2021). ____. 2021b. Designated Critical Habitat Portal [online]. http://criticalhabitat.fws.gov/crithab/ (accessed October 2021).
____. 2021c. National Wetlands Inventory Online Application. http://www.fws.gov/wetlands/Data/Mapper.html (accessed October 2021). ____. 2011. California Red-legged Frog (Rana draytonii) species account. Arcata Fish and Wildlife Office, Arcata, California. https://www.fws.gov/arcata/es/amphibians/crlf/crlf.html (accessed October 2021).

United States Geological Service (USGS). 2021. National Hydrography Dataset. https://nhd.usgs.gov/index.html (accessed October 2021).

University of California, Berkeley. 2020. University and Jepson Herberia. https://ucjeps.berkeley.edu/interchange/ [Accessed October 2021].

WRA (Wildlife Research Associates). 2014. Technical Memorandum Biotic Study: 805 Los Trancos Road, Palo Alto, California. May 27, 2008. Updated October 16, 2014.

Zeiner, D., W.F. Laudenslayer, Jr., and K.E. Mayer. 1988-1990. California’s Wildlife. California Statewide Wildlife Habitat Relationship System, Volumes I, II, & III. California Department of Fish and Wildlife.

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Attachment 1
Figures

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Figure 1 Regional Location

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Figure 2 Land Cover Types

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Attachment 2
Representative Site Photographs
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Photograph 1. Overview of the coast live oak woodland within the project site. Photograph taken from the northern end of the project site, facing south.

Photograph 2. View of mowed non-native annual grassland surrounded by the oak woodland within the project area facing the northern boundary of the project area.

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Photograph 3. Photograph of Los Trancos creek immediately adjacent to the west of the project area.

Photograph 4. San Francisco dusky footed woodrat nest within the project area.

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Photograph 5. View of the oak woodland at the southern extent of the project area.

Photograph 6. View of the riparian woodland along the southern extent of the project area.

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Photograph 7. Representative photo of the oak woodland within the project area.

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Attachment 3
Plant Species List Observed
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Scientific Name Common Name Origin & Cal-IPC Status1
Aesculus californica California buckeye Native
Artemesia douglasiana mugwort Native
Avena spp. wild oats Introduced; Cal-IPC Moderate
Bromus diandrus ripgut grass Introduced; Cal-IPC Moderate Cynodon dactylon Bermuda grass Introduced; Cal-IPC Moderate Genista monspessulana French broom Introduced; Cal-IPC High Plantago lanceolata English plantain Introduced; Cal-IPC Limited Quercus agrifolia Coast live oak Native
Quercus lobata valley oak Native
Rubus armeniacus Himalayan blackberry Introduced; Cal-IPC High Salix lasiolepis arroyo willow Native
Toxicodendron diversilobum poison oak Native
Umbellularia californica California bay Native
1 Cal-IPC: California Invasive Plant Council ratings

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Attachment 4
Wildlife Species List Observed
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Scientific Name Common Name
Neotoma fuscipes annectens San Francisco dusky-footed woodrat Dryobates nuttallii Nuttall’s woodpecker
Melanerpes formicivorus Acorn woodpecker
Sciurus niger Fox squirrel
Cyanocitta stelleri Steller’s jay
Certhia americana Brown creeper
Sciurus carolinensis Eastern gray squirrel
Melozone crissalis California towhee
Junco hyemalis Dark eyed junco

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Attachment 5
Special-Status Species Evaluation Tables

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Special-Status Plant Species in the Regional Vicinity (Nine Quad) of the Project Site Scientific Name
Common Name
Status
Fed/State ESA
CRPR Habitat Requirements
Potential to
Occur Rationale
Acanthomintha
duttonii
San Mateo thorn-
mint
FE/SE
G1/S1
1B.1
Chaparral, Valley and foothill
grassland. Uncommon
serpentinite vertisol clays; in
relatively open areas. 50-
300m. Blooms Apr-Jun.

Not Expected
Suitable serpentine soils not
present. One historic
occurrence from 1977 has
been recorded within 5 miles,
approximately 5 miles to the
north of the site, and is
considered extirpated (CDFW
2021a).

Allium peninsulare
var. franciscanum
Franciscan onion
None/None
G5T2/S2
1B.2
Cismontane woodland, Valley
and foothill grassland. Clay
soils; often on serpentine;
sometimes on volcanics. Dry
hillsides. 52-305m. Blooms
(Apr)May-Jun.

Not Expected
Suitable woodland habitat
and grasslands are present.

No native grassland
communities are present
within the site. Clay soils are
present; however, no
serpentine formations occur
within the project site. One
recent occurrence from 2013
is recorded within 5 miles of
the project site,
approximately 3.25 miles to
the northeast (CDFW 2021a).

Amsinckia lunaris
bent-flowered
fiddleneck
None/None
G3/S3
1B.2
Cismontane woodland, Coastal
bluff scrub, Valley and foothill
grassland. 3-500m. Blooms
Mar-Jun.

Not Expected
Grasslands and coast live oak
woodland are present. The
non-native grasslands present
are not a natural vegetation
community and are
frequently disturbed by
mowing. No occurrences have
been reported within 5 miles
(CDFW 2021a).

Arctostaphylos
andersonii
Anderson's
manzanita
None/None
G2/S2
1B.2
Broadleafed upland forest,
Chaparral, North Coast
coniferous forest. Open sites,
redwood forest. 60-760m.

Blooms Nov-May.

Not Expected
Suitable vegetation
communities absent. This
species would have been
observed if present.

Arctostaphylos
regismontana
Kings Mountain
manzanita
None/None
G2/S2
1B.2
Broadleafed upland forest,
Chaparral, North Coast
coniferous forest. Granitic or
sandstone outcrops. 305-
730m. Blooms Dec-Apr.

Not Expected
Suitable vegetation
communities, elevations, and
rock outcrops absent. Would
have been observed if
present.

Astragalus
pycnostachyus var.
pycnostachyus
coastal marsh milk-
vetch
None/None
G2T2/S2
1B.2
Coastal dunes, Coastal scrub,
Marshes and swamps. Mesic
sites in dunes or along streams
or coastal salt marshes. 0-30m.

Blooms (Apr)Jun-Oct.

Not Expected
No suitable habitat or
elevations occurs in the
project site.

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Scientific Name
Common Name
Status
Fed/State ESA
CRPR Habitat Requirements
Potential to
Occur Rationale
Astragalus tener
var. tener
alkali milk-vetch
None/None
G2T1/S1
1B.2
Playas, Valley and foothill
grassland, Vernal pools. Low
ground, alkali flats, and
flooded lands; in annual
grassland or in playas or vernal
pools. 1-60m. Blooms Mar-Jun.

Not Expected
No suitable habitat occurs in
the project site. Outside of
suitable elevation.

Centromadia parryi
ssp. congdonii
Congdon's tarplant
None/None
G3T1T2/S1S2
1B.1
Valley and foothill grassland.

Alkaline soils, sometimes
described as heavy white clay.
0-230m. Blooms May-
Oct(Nov).

Not Expected
Suitable soils absent.

Chloropyron
maritimum ssp.
palustre
Point Reyes salty
bird's-beak
None/None
G4?T2/S2
1B.2
Marshes and swamps. Usually
in coastal salt marsh with
Salicornia, Distichlis, Jaumea,
Spartina, etc. 0-10m. Blooms
Jun-Oct.

Not Expected
No suitable habitat occurs in
the project site.

Chorizanthe
pungens var.
hartwegiana
Ben Lomond
spineflower
FE/None
G2T1/S1
1B.1
Lower montane coniferous
forest. Zayante coarse sands in
maritime ponderosa pine
sandhills. 90-610m. Blooms
Apr-Jul.

Not Expected
No suitable habitat occurs in
the project and it does not
contain maritime ponderosa
forests.

Cirsium fontinale
var. fontinale
fountain thistle
FE/SE
G2T1/S1
1B.1
Chaparral, Cismontane
woodland, Meadows and
seeps, Valley and foothill
grassland. Serpentine seeps
and grassland. 45-175m.

Blooms (Apr)May-Oct.

Not Expected
No suitable habitat occurs in
the project site and
serpentine soils are not
present.

Collinsia corymbosa
round-headed
Chinese-houses
None/None
G1/S1
1B.2
Coastal dunes. 0-20m. Blooms
Apr-Jun. Not Expected
No suitable habitat or
elevations occur in the project
site.

Collinsia multicolor
San Francisco
collinsia
None/None
G2/S2
1B.2
Annual herb. Blooms
March-May. Closed-cone
coniferous forest, coastal
scrub. On decomposed shale
(mudstone) mixed with humus.
30-250m (100-820ft).

Not Expected
Closed cone coniferous
forests and suitable soils are
absent.

Dirca occidentalis
western
leatherwood
None/None
G2/S2
1B.2
Broadleafed upland forest,
Chaparral, Cismontane
woodland, Closed-cone
coniferous forest, North Coast
coniferous forest, Riparian
forest, Riparian woodland. On
brushy slopes, mesic sites;
mostly in mixed evergreen &
foothill woodland
communities. 25-425m.

Blooms Jan-Mar(Apr).

Not Expected
Suitable habitat, including
riparian woodland is present
on the project site; however,
this species would have been
observed if present.

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Scientific Name
Common Name
Status
Fed/State ESA
CRPR Habitat Requirements
Potential to
Occur Rationale
Eriophyllum
latilobum
San Mateo woolly
sunflower
FE/SE
G1/S1
1B.1
Cismontane woodland, Coastal
scrub, Lower montane
coniferous forest. Often on
roadcuts; found on and off of
serpentine. 45-330m. Blooms
May-Jun.

Low
Potential
Coast live oak woodland is
present. One historic
occurrence from 1962 is
recorded within 5 miles of the
project site, approximately

1.8 miles to the southwest
(CDFW 2021a).

Eryngium
aristulatum var.
hooveri
Hoover's button-
celery
None/None
G5T1/S1
1B.1
Vernal pools. Alkaline
depressions, vernal pools,
roadside ditches and other wet
places near the coast. 3-45m.

Blooms (Jun)Jul(Aug).

Not Expected
No suitable habitat occurs in
the project site, which outside
of known elevation for this
species.

Eryngium jepsonii
Jepson's coyote-
thistle
None/None
G2/S2
1B.2
Valley and foothill grassland,
Vernal pools. Clay. 3-300m.

Blooms Apr-Aug.

Not Expected
No vernal pools within the
project site. Suitable soils not
present
Fissidens
pauperculus
minute pocket moss
None/None
G3?/S2
1B.2
North Coast coniferous forest.

Moss growing on damp soil
along the coast. In dry
streambeds and on stream
banks. 10-1024m.

Not Expected
No suitable habitat occurs in
the project site, and no
occurrences have been
recorded within 5 miles
(CDFW 2021a).

Fritillaria liliacea
fragrant fritillary
None/None
G2/S2
1B.2
Cismontane woodland, Coastal
prairie, Coastal scrub, Valley
and foothill grassland. Often
on serpentine; various soils
reported though usually on
clay, in grassland. 3-410m.

Blooms Feb-Apr.

Low
Potential
Suitable habitat present
although no serpentine soils
were observed on the project
site. One historical occurrence
from 1932 has been recorded
within 5 miles of the project
site, approximately 2.5 miles
to the north (CDFW 2021a).

Hesperocyparis
abramsiana var.
abramsiana
Santa Cruz cypress
FT/SE
G1T1/S1
1B.2
Chaparral, Closed-cone
coniferous forest, Lower
montane coniferous forest.

Restricted to the Santa Cruz
Mountains, on sandstone &
granitic-derived soils; often
w/Pinus attenuata, redwoods.
280-800m. Blooms .

Not Expected
No suitable habitat or
elevation occurs in the project
site. Would have been
observed if present.

Hesperocyparis
abramsiana var.
butanoensis
Butano Ridge
cypress
FT/SE
G1T1/S1
1B.2
Chaparral, Closed-cone
coniferous forest, Lower
montane coniferous forest.

Sandstone. 400-490m. Blooms
Oct.

Not Expected
No suitable habitat or
elevation occurs in the project
site. Would have been
observed if present.

Hesperolinon
congestum
Marin western flax
FT/ST
G1/S1
1B.1
Chaparral, Valley and foothill
grassland. In serpentine
barrens and in serpentine
grassland and chaparral. 5-
370m. Blooms Apr-Jul.

Not Expected Suitable soils are absent.

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
161
Packet Page 591 of 792

Scientific Name
Common Name
Status
Fed/State ESA
CRPR Habitat Requirements
Potential to
Occur Rationale
Hoita strobilina
Loma Prieta hoita
None/None
G2?/S2?
1B.1
Chaparral, Cismontane
woodland, Riparian woodland.

Serpentine; mesic sites. 30-
860m. Blooms May-Jul (Aug-
Oct).

Not Expected
Although suitable woodlands,
including riparian woodlands
occur on the project site,
suitable serpentine soils are
absent and no occurrences
have been recorded within 5
miles.

Legenere limosa
legenere
None/None
G2/S2
1B.1
Vernal pools. In beds of vernal
pools. 1-880m. Blooms Apr-
Jun.

Not Expected
No suitable vernal pool
habitat occurs in the project
site.

Limnanthes
douglasii ssp.
sulphurea
Point Reyes
meadowfoam
None/SE
G4T1/S1
1B.2
Coastal prairie, Marshes and
swamps, Meadows and seeps,
Vernal pools. Vernally wet
depressions in open rolling,
coastal prairies and meadows;
typically in dark clay soil. 0-
140m. Blooms Mar-May.

Not Expected No suitable habitat occurs in
the project site.

Malacothamnus
arcuatus
arcuate bush-
mallow
None/None
G2Q/S2
1B.2
Chaparral, Cismontane
woodland. Gravelly alluvium.
15-355m. Blooms Apr-Sep.

Low
Potential
Suitable woodland habitat is
present; however, regular
vegetation maintenance
decreases the likelihood of
their occurrence. No
individuals were observed
during the site visit.Two
recent occurrences (2013 and
2015) have been recorded
within 5 miles of the project
site (CDFW 2021a).

Monolopia gracilens
woodland
woollythreads
None/None
G3/S3
1B.2
Broadleafed upland forest,
Chaparral, Cismontane
woodland, North Coast
coniferous forest, Valley and
foothill grassland. Grassy sites,
in openings; sandy to rocky
soils. Often seen on serpentine
after burns, but may have only
weak affinity to serpentine.
100-1200m. Blooms (Feb)Mar-
Jul.

Moderate
Potential
Suitable habitat is present
within the project site and
three recent occurrences
(2015-2018) have been
recorded within 5 miles of the
project site (CDFW 2021a).

Pedicularis dudleyi
Dudley's lousewort
None/SR
G2/S2
1B.2
Chaparral, Cismontane
woodland, North Coast
coniferous forest, Valley and
foothill grassland. Deep shady
woods of older coast redwood
forests; also in maritime
chaparral. 60-900m. Blooms
Apr-Jun.

Low
Potential
Woodland habitat occurs on
the project site however,
deep shady forests and
maritime chapparal are
absent. No occurrences have
been recorded within 5 miles
(CDFW 2021a).

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
162
Packet Page 592 of 792

Scientific Name
Common Name
Status
Fed/State ESA
CRPR Habitat Requirements
Potential to
Occur Rationale
Pentachaeta
bellidiflora
white-rayed
pentachaeta
FE/SE
G1/S1
1B.1
Cismontane woodland, Valley
and foothill grassland. Open
dry rocky slopes and grassy
areas, often on soils derived
from serpentine bedrock. 35-
620m. Blooms Mar-May.

Not Expected
The annual grassland present
on the project site is not a
natural grassland community
and is regularly maintained,
thus would not provide
suitable habitat. No
occurrences have been
recorded within 5 miles
(CDFW 2021a).

Piperia candida
white-flowered rein
orchid
None/None
G3/S3
1B.2
Broadleafed upland forest,
Lower montane coniferous
forest, North Coast coniferous
forest. Sometimes on
serpentine. Forest duff, mossy
banks, rock outcrops, and
muskeg. 30-1310m. Blooms
(Mar)May-Sep.

Not Expected
No suitable habitat occurs in
the project site. Only one
occurrence from 1992 has
been recorded within 5 miles
of the project site (CDFW
2021a).

Plagiobothrys
chorisianus var.
chorisianus
Choris'
popcornflower
None/None
G3T1Q/S1
1B.2
Chaparral, Coastal prairie,
Coastal scrub. Mesic sites. 3-
160m. Blooms Mar-Jun.

Not Expected No suitable habitat occurs in
the project site.

Plagiobothrys
diffusus
San Francisco
popcornflower
None/SE
G1Q/S1
1B.1
Coastal prairie, Valley and
foothill grassland. Historically
from grassy slopes with marine
influence. 60-360m. Blooms
Mar-Jun.

Not Expected
Grasslands present in the
project site are not natural
grassland communities and
no occurrences have been
recorded within 5 miles
(CDFW 2021a).

Senecio aphanactis
chaparral ragwort
None/None
G3/S2
2B.2
Chaparral, Cismontane
woodland, Coastal scrub.

Drying alkaline flats. 15-800m.

Blooms Jan-Apr(May).

Not Expected No suitable soils occur in the
project site.

Stuckenia filiformis
ssp. alpina
slender-leaved
pondweed
None/None
G5T5/S2S3
2B.2
Marshes and swamps. Shallow,
clear water of lakes and
drainage channels. 300-2150m.

Blooms May-Jul.

Not Expected
No suitable habitat nor
elevation occurs in the project
site
Suaeda californica
California seablite
FE/None
G1/S1
1B.1
Marshes and swamps. Margins
of coastal salt marshes. 0-15m.

Blooms Jul-Oct.

Not Expected No suitable habitat occurs in
the project site.

Trifolium amoenum
two-fork clover
FE/None
G1/S1
1B.1
Coastal bluff scrub, Valley and
foothill grassland. Sometimes
on serpentine soil, open sunny
sites, swales. Most recently
cited on roadside and eroding
cliff face. 5-415m. Blooms Apr-
Jun.

Low
Potential
Grassland habitat is present;
however, it is non-native, and
not a natural community. One
historical occurrence has
been recorded in 1950,
approximately 3 miles north
of the project site (CDFW
2021a).

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
163
Packet Page 593 of 792

Scientific Name
Common Name
Status
Fed/State ESA
CRPR Habitat Requirements
Potential to
Occur Rationale
Trifolium
buckwestiorum
Santa Cruz clover
None/None
G2/S2
1B.1
Broadleafed upland forest,
Cismontane woodland, Coastal
prairie. Moist grassland.

Gravelly margins. 105-610m.

Blooms Apr-Oct.

Low
Potential
Suitable woodland habitat is
present; however, no
occurrences have been
recorded within five miles of
the project site (CDFW
2021a).

Trifolium
hydrophilum
saline clover
None/None
G2/S2
1B.2
Marshes and swamps, Valley
and foothill grassland, Vernal
pools. Mesic, alkaline sites. 0-
300m. Blooms Apr-Jun.

Not Expected
No alkaline soils or suitable
natural vegetation
communities occur within the
project site. No occurrences
have been recorded within
five (CDFW 2021a).

Regional Vicinity refers to within a 9-quad search radius of site.

FE = Federally Endangered FT = Federally Threatened FC = Federal Candidate Species SE = State Endangered ST = State Threatened SC = State Candidate SR = State Rare CRPR (CNPS California Rare Plant Rank):
1A=Presumed Extinct in California
1B=Rare, Threatened, or Endangered in California and elsewhere 2A=Plants presumed extirpated in California, but more common elsewhere 2B=Plants Rare, Threatened, or Endangered in California, but more common elsewhere CRPR Threat Code Extension:
.1=Seriously endangered in California (over 80% of occurrences threatened / high degree and immediacy of threat) .2=Fairly endangered in California (20-80% occurrences threatened) .3=Not very endangered in California (<20% of occurrences threatened) ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
164
Packet Page 594 of 792

Special-Status Animal Species in the Regional Vicinity (Nine Quad) of the Project Site Scientific Name
Common Name
Status
Fed/State ESA
CDFW Habitat Requirements
Potential
to Occur Rationale
Invertebrates
Euphydryas editha
bayensis
Bay checkerspot
butterfly
FT/None
G5T1/S1
Restricted to native grasslands on outcrops of
serpentine soil in the vicinity of San Francisco
Bay. Plantago erecta is the primary host plant;
Orthocarpus densiflorus & O. purpurscens are
the secondary host plants.

Not
Expected
No suitable habitat
present within the
project site
Speyeria zerene
myrtleae
Myrtle's silverspot
butterfly
FE/None
G5T1/S1
Restricted to the foggy, coastal dunes/hills of
the Point Reyes peninsula; extirpated from
coastal San Mateo County. Larval foodplant
thought to be Viola adunca.

Not
Expected
No suitable habitat
present within the
project site, species has
been extirpated from its
range in the vicinity of
the project site.

Fish
Oncorhynchus
mykiss irideus
pop. 8
steelhead - central
California coast
DPS
FT/None
G5T2T3Q/S2S3
DPS includes all naturally spawned
populations of steelhead (and their progeny)
in streams from the Russian River to Aptos
Creek, Santa Cruz County, California
(inclusive). Also includes the drainages of San
Francisco and San Pablo Bays.

High
Potential
Steelhead are known in
the San Francisquito
Creek watershed and
have been observed in
Los Trancos Creek (Leidy
et al. 2005).

Spirinchus
thaleichthys
longfin smelt
FC/ST
G5/S1
Euryhaline, nektonic & anadromous. Found in
open waters of estuaries, mostly in middle or
bottom of water column. Prefer salinities of
15-30 ppt, but can be found in completely
freshwater to almost pure seawater.

Not
Expected
No suitable habitat
present within the
project site
Amphibians
Aneides niger
Santa Cruz black
salamander
None/None
G3/S3
SSC
Mixed deciduous and coniferous woodlands
and coastal grasslands in San Mateo, Santa
Cruz, and Santa Clara counties. Adults found
under rocks, talus, and damp woody debris.

Moderate
Potential
Suitable habitat is
present, there are five
records within five miles
of the project site
Dicamptodon
ensatus
California giant
salamander
None/None
G3/S2S3
SSC
Known from wet coastal forests near streams
and seeps from Mendocino County south to
Monterey County, and east to Napa County.

Aquatic larvae found in cold, clear streams,
occasionally in lakes and ponds. Adults known
from wet forests under rocks and logs near
streams and lakes.

Moderate
Potential
Suitable habitat is
present, there are five
records within five miles
of the project site
Rana boylii
foothill yellow-
legged frog
None/SE
G3/S3
SSC
Partly-shaded, shallow streams and riffles with
a rocky substrate in a variety of habitats.

Needs at least some cobble-sized substrate for
egg-laying. Needs at least 15 weeks to attain
metamorphosis.

Not
Expected
Suitable habitat is
present however, the
species is presumed to
be extirpated from the
region.

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
165
Packet Page 595 of 792

Scientific Name
Common Name
Status
Fed/State ESA
CDFW Habitat Requirements
Potential
to Occur Rationale
Rana draytonii
California red-
legged frog
FT/None
G2G3/S2S3
SSC
Lowlands and foothills in or near permanent
sources of deep water with dense, shrubby or
emergent riparian vegetation. Requires 11-20
weeks of permanent water for larval
development. Must have access to estivation
habitat.

Moderate
Potential
Suitable foraging habitat
is present with in the
project site. There are 10
recorded occurrences
within five miles of the
project site (CDFW
2021a). The nearest
breeding habitat is
approximately 2.6 miles
north in San Francisquito
Creek.

Reptiles
Emys marmorata
western pond
turtle
None/None
G3G4/S3
SSC
A thoroughly aquatic turtle of ponds, marshes,
rivers, streams and irrigation ditches, usually
with aquatic vegetation, below 6000 ft
elevation. Needs basking sites and suitable
(sandy banks or grassy open fields) upland
habitat up to 0.5 km from water for egg-laying.

Moderate
Potential
Suitable habitat for
breeding and foraging is
present within the
project site. There are
three records within five
miles of the project site,
closest record is
approximately 2.9 miles
north in San Francisquito
Creek.

Thamnophis
sirtalis tetrataenia
San Francisco
gartersnake
FE/SE
G5T2Q/S2
FP
Vicinity of freshwater marshes, ponds and
slow-moving streams in San Mateo County
and extreme northern Santa Cruz County.

Prefers dense cover and water depths of at
least one foot. Upland areas near water are
also very important.

Moderate
Potential
Suitable habitat is
present and there are 13
recorded occurrences
within five miles of the
project site (CDFW
2021a).

Birds
Asio flammeus
short-eared owl
None/None
G5/S3
SSC
Found in swamp lands, both fresh and salt;
lowland meadows; irrigated alfalfa fields. Tule
patches/tall grass needed for nesting/daytime
seclusion. Nests on dry ground in depression
concealed in vegetation.

Not
Expected
Suitable habitat is not
present and there are no
recorded occurrences
within five miles of the
project site (CDFW
2021a).

Asio otus
long-eared owl
None/None
G5/S3?
SSC
Riparian bottomlands grown to tall willows
and cottonwoods; also, belts of live oak
paralleling stream courses. Require adjacent
open land, productive of mice and the
presence of old nests of crows, hawks, or
magpies for breeding.

Low
Potential
Suitable habitat is
present. One historic
occurrence from 1987
has been recorded
within 5 miles of the
project site,
approximately 4 miles to
the southeast (CDFW
2021a).

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
166
Packet Page 596 of 792

Scientific Name
Common Name
Status
Fed/State ESA
CDFW Habitat Requirements
Potential
to Occur Rationale
Athene cunicularia
burrowing owl
None/None
G4/S3
SSC
Open, dry annual or perennial grasslands,
deserts, and scrublands characterized by low-
growing vegetation. Subterranean nester,
dependent upon burrowing mammals, most
notably, the California ground squirrel.

Not
Expected
No suitable habitat is
present within the
project site. Grassland
present on the site is
routinely mowed and
disturbed. The only
recorded occurrence
within 5 miles is from
2017, approximately 2.8
miles south of the
project site (CDFW
2021a).

Brachyramphus
marmoratus
marbled murrelet
FT/SE
G3/S2
Feeds near-shore; nests inland along coast
from Eureka to Oregon border and from Half
Moon Bay to Santa Cruz. Nests in old-growth
redwood-dominated forests, up to six miles
inland, often in Douglas-fir.

Not
Expected
No suitable habitat
present and the project
site is 11 miles inland,
outside of the known
species range.

Charadrius
nivosus nivosus
western snowy
plover
FT/None
G3T3/S2
SSC
Sandy beaches, salt pond levees & shores of
large alkali lakes. Needs sandy, gravelly or
friable soils for nesting.

Not
Expected
No suitable habitat
present within the
project site.

Circus hudsonius
northern harrier
None/None
G5/S3
SSC
Coastal salt & freshwater marsh. Nest and
forage in grasslands, from salt grass in desert
sink to mountain cienagas. Nests on ground in
shrubby vegetation, usually at marsh edge;
nest built of a large mound of sticks in wet
areas.

Not
Expected
Although suitable
foraging habitat is
present within the
project site, no nearby
marshes are known and
no occurrences have
been recorded within
five miles of the project
site (CDFW 2021a).

Coturnicops
noveboracensis
yellow rail
None/None
G4/S1S2
SSC
Summer resident in eastern Sierra Nevada in
Mono County. Small numbers winter regularly
in the San Francisco Bay estuary.

Not
Expected
Outside of usual species
range and no suitable
habitat present within
the project site.

Elanus leucurus
white-tailed kite
None/None
G5/S3S4
FP
Rolling foothills and valley margins with
scattered oaks & river bottomlands or
marshes next to deciduous woodland. Open
grasslands, meadows, or marshes for foraging
close to isolated, dense-topped trees for
nesting and perching.

Not
Expected
No suitable habitat
present within the
project site.

Falco peregrinus
anatum
American
peregrine falcon
FD/SD
G4T4/S3S4
FP
Near wetlands, lakes, rivers, or other water;
on cliffs, banks, dunes, mounds; also, human-
made structures. Nest consists of a scrape or a
depression or ledge in an open site.

Not
Expected
No suitable nesting
habitat present within
the project site.

Geothlypis trichas
sinuosa
saltmarsh
common
yellowthroat
None/None
G5T3/S3
SSC
Resident of the San Francisco Bay region, in
fresh and salt water marshes. Requires thick,
continuous cover down to water surface for
foraging; tall grasses, tule patches, willows for
nesting.

Not
Expected
No suitable habitat
present within the
project site.

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
167
Packet Page 597 of 792

Scientific Name
Common Name
Status
Fed/State ESA
CDFW Habitat Requirements
Potential
to Occur Rationale
Haliaeetus
leucocephalus
bald eagle
FD/SE
G5/S3
FP
Ocean shore, lake margins, and rivers for both
nesting and wintering. Most nests within 1
mile of water. Nests in large, old-growth, or
dominant live tree with open branches,
especially ponderosa pine. Roosts communally
in winter.

Not
Expected
No suitable nesting or
foraging habitat present
within the project site.

Laterallus
jamaicensis
coturniculus
California black
rail
None/ST
G3G4T1/S1
FP
Inhabits freshwater marshes, wet meadows
and shallow margins of saltwater marshes
bordering larger bays. Needs water depths of
about 1 inch that do not fluctuate during the
year and dense vegetation for nesting habitat.

Not
Expected
No suitable habitat
present within the
project site
Melospiza
melodia pusillula
Alameda song
sparrow
None/None
G5T2?/S2S3
SSC
Resident of salt marshes bordering south arm
of San Francisco Bay. Inhabits Salicornia
marshes; nests low in Grindelia bushes (high
enough to escape high tides) and in Salicornia.

Not
Expected
No suitable habitat
present within the
project site.

Rallus obsoletus
obsoletus
California
Ridgway's rail
FE/SE
G3T1/S1
FP
Salt water and brackish marshes traversed by
tidal sloughs in the vicinity of San Francisco
Bay. Associated with abundant growths of
pickleweed, but feeds away from cover on
invertebrates from mud-bottomed sloughs.

Not
Expected
No suitable habitat
present within the
project site.

Rynchops niger
black skimmer
None/None
G5/S2
SSC
Nests on gravel bars, low islets, and sandy
beaches, in unvegetated sites. Nesting
colonies usually less than 200 pairs. .

Not
Expected
No suitable nesting or
foraging habitat present
within the project site.

Sternula
antillarum browni
California least
tern
FE/SE
G4T2T3Q/S2
FP
Nests along the coast from San Francisco Bay
south to northern Baja California. Colonial
breeder on bare or sparsely vegetated, flat
substrates: sand beaches, alkali flats, land fills,
or paved areas.

Not
Expected
No suitable habitat
present within the
project site.

Mammals
Antrozous pallidus
pallid bat
None/None
G4/S3
SSC
Found in a variety of habitats including
deserts, grasslands, shrublands, woodlands,
and forests. Most common in open, dry
habitats with rocky areas for roosting. Roosts
in crevices of rock outcrops, caves, mine
tunnels, buildings, bridges, and hollows of live
and dead trees which must protect bats from
high temperatures. Very sensitive to
disturbance of roosting sites.

Moderate
Potential
Suitable habitat is
present and there are
three recorded
occurrences within five
miles of the project site
(CDFW 2021a).

Corynorhinus
townsendii
Townsend's big-
eared bat
None/None
G4/S2
SSC
Occurs throughout California in a wide variety
of habitats. Most common in mesic sites,
typically coniferous or deciduous forests.

Roosts in the open, hanging from walls &amp;
ceilings in caves, lava tubes, bridges, and
buildings. This species is extremely sensitive to
human disturbance.

Moderate
Potential
Suitable habitat is
present and there are 13
recorded occurrences
within five miles of the
project site (CDFW
2021a).

Neotoma fuscipes
annectens
San Francisco
dusky-footed
woodrat
None/None
G5T2T3/S2S3
SSC
Typically found in forest habitats with
moderate to dense understory. Can occur in
chaparral, riparian woodlands, and coniferous
forests, particularly redwood. Builds middens
out of grasses, leaves, and woody debris. This
subspecies is found only in the San Francisco
Bay region.

Present
Nests were observed
during reconnaissance
surveys.

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
168
Packet Page 598 of 792

Scientific Name
Common Name
Status
Fed/State ESA
CDFW Habitat Requirements
Potential
to Occur Rationale
Reithrodontomys
raviventris
salt-marsh harvest
mouse
FE/SE
G1G2/S1S2
FP
Only in the saline emergent wetlands of San
Francisco Bay and its tributaries. Pickleweed is
primary habitat but may occur in other marsh
vegetation types and in adjacent upland areas.

Does not burrow; builds loosely organized
nests. Requires higher areas for flood escape.

Not
Expected
No suitable habitat
present within the
project site.

Sorex vagrans
halicoetes
salt-marsh
wandering shrew
None/None
G5T1/S1
SSC
Salt marshes of the south arm of San Francisco
Bay. Medium high marsh 6-8 ft above sea level
where abundant driftwood is scattered among
Salicornia.

Not
Expected
No suitable habitat
present within the
project site.

Taxidea taxus
American badger
None/None
G5/S3
SSC
Most abundant in drier open stages of most
shrub, forest, and herbaceous habitats, with
friable soils. Needs sufficient food, friable soils
and open, uncultivated ground. Preys on
burrowing rodents. Digs burrows.

Not
Expected
No suitable habitat
present within the
project site.

Regional Vicinity refers to within a 5-mile search radius of site.

FE = Federally Endangered FT = Federally Threatened FC = Federal Candidate Species FS=Federally Sensitive SE = State Endangered ST = State Threatened SC = State Candidate SS=State Sensitive SSC = CDFW Species of Special Concern SFP = State Fully Protected

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Appendix B
Arborist Report
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Kielty Arborist Services LLC
Certified Arborist WE#0476A
P.O. Box 6187
San Mateo, CA 94403
650-515-9783
June 7th, 2021, Revised August 24th, 2021

Innovative Homes, LLC
c/o: John Suppes
412 Olive Avenue
Palo Alto, CA 94306

Site: 575 Los Trancos Road, Palo Alto CA

Dear Innovative Homes, LLC,

As requested on Friday May 28
th, 2021, Kielty Arborist Services visited the above site to inspect and comment on the trees. Your concerns as to the future health and safety of the trees has prompted this letter. A review of the trees and a tree protection plan will be found within this report. Preliminary site plan A1.1 dated 4/8/21 has been reviewed as a part of this report.

Method:

All inspections were made from the ground; the trees were not climbed for this inspection. The trees in question were located on an existing topography map provided by you. The trees were then measured for diameter at 54 inches above ground level (DBH or diameter at breast height).

The trees were given a condition rating for form and vitality. The trees condition ratings are based on 50 percent vitality and 50 percent form, using the following scale.

1 - 29 Very Poor
30 - 49 Poor
50 - 69 Fair
70 - 89 Good
90 - 100 Excellent

The height of the trees was measured using a Nikon Forestry 550 Hypsometer. The spread was paced off. Comments and recommendations for future maintenance are provided.

Survey Key:

DBH-Diameter at breast height (54” above grade)
CON- Condition rating (1-100)
HT/SP- Tree height/ canopy spread
*indicates neighbor’s trees
P-Indicates protected tree by city ordinance
R-Indicates proposed tree removal

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575 Los Trancos (2)
Survey:

Tree# Species DBH CON HT/SP Comments
1P Coast live oak 28.0 65 50/30 Good vigor, good form, near utilities and (Quercus agrifolia) existing driveway.

2P Coast live oak 19.5 60 45/30 Fair vigor, fair form, codominant at 8 feet (Quercus agrifolia) with fair union, suppressed.

3P Coast live oak 39.3 70 45/55 Good vigor, fair form, heavy laterals, (Quercus agrifolia) aesthetically pleasing, recommended to cable and prune heavy leaders.

4P Valley oak 44.1 60 65/50 Fair vigor, fair form, minor dead wood, 10” (Quercus lobata) and 6” dead limbs observed, codominant at 20 feet, heavy lateral limbs, history of limb
loss, recommended to removed dead wood.

5P Valley oak 22.4 60 55/35 Fair vigor, fair form, suppressed, tall for (Quercus lobata) diameter.

6P Valley oak 39.4 55 60/60 Fair vigor, poor form, codominant at 6 feet, (Quercus lobata) heavy into site, one side of canopy pruned for utilities, bleeding canker on trunk,
recommended to treat canker, prune
where heavy and cable where possible.

7P Coast live oak 25.5 60 55/35 Fair vigor, fair form, suppressed, history of (Quercus agrifolia) limb loss.

8P Valley oak 25.7 65 60/35 Fair vigor, fair form, suppressed. (Quercus lobata)

9P Coast live oak 20.4 50 35/35 Fair vigor, poor form, heavily suppressed, (Quercus agrifolia) grows towards street.

10P Coast live oak 35.0 70 60/45 Good vigor, fair form, large 10” dead limb. (Quercus agrifolia) recommended to remove dead limb.

11P Coast live oak 36.9 45 35/50 Good vigor, poor form, grows horizontally. (Quercus agrifolia) recommended to prop and prune if retained.

12P Valley oak 22.5-17.9 65 50/50 Good vigor, fair form, codominant at 2 feet, (Quercus lobata) heavy into site.

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575 Los Trancos (3)
Survey:

Tree# Species DBH CON HT/SP Comments
13P Coast live oak 22.8 45 35/30 Good vigor, poor form, topped for utilities. (Quercus agrifolia)

14 Bay 12.2-12 30 20/12 Poor vigor, poor form, dead leader, decay at (Umbellularia californica) root crown, topped.

15 Coast live oak 10.1 50 30/12 Fair vigor, poor form, topped for line (Quercus agrifolia) clearance.

16P Coast live oak 13.8 50 30/15 Fair vigor, poor form, topped for line (Quercus agrifolia) clearance.

17P Valley oak 48.8 70 65/65 Good vigor, good form, mature. (Quercus lobata) recommended to prune where heavy and to cable codominant leaders.

18P Coast live oak 22.0 70 45/30 Good vigor, fair form. (Quercus agrifolia)

19P Coast live oak 22.6-16.8 65 45/45 Fair vigor, fair form, multi leader at grade, (Quercus agrifolia) 13.6 minor dead wood.

20P Valley oak 29.8 40 50/40 Fair to poor vigor, poor form, c odominant at (Quercus lobata) 10 feet, codominant leader is dead, decay at root crown, recommended to expose root
crown and inspect, remove dead
codominant leader.

21P Valley oak 35.2 70 60/60 Fair vigor, fair form, heavy lateral limbs. (Quercus lobata)

22P Valley oak 26.3 60 60/60 Fair vigor, fair form, suppressed, signs of (Quercus lobata) decay at root crown, recommended to expose root crown and inspect.

23P Coast live oak 17.0 65 50/30 Fair vigor, fair form, slight lean into site. (Quercus agrifolia)

24P Coast live oak 17.2 50 25/35 Fair vigor, poor form, suppressed, heavy lean (Quercus agrifolia) well pruned.

25P Coast live oak 37.5 65 60/60 Fair vigor, fair form, codominant at 12 feet. (Quercus agrifolia) recommended to prune and cable.

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575 Los Trancos (4)
Survey:

Tree# Species DBH CON HT/SP Comments
26P Coast live oak 24-10 40 10/40 Good vigor, poor form, grows horizontally, (Quercus agrifolia) suppressed, recommended to prop and prune.

27P Coast live oak 32.1-22 60 60/60 Fair vigor, fair form, codominant at grade. (Quercus agrifolia) recommended to cable and prune
codominant leaders.

28 Bay 14.9 50 45/30 Fair vigor, fair form, suppressed. (Umbellularia californica)

29 Black walnut 29.6 30 50/45 Poor vigor, poor form, in decline. (Juglans nigra)

30P Coast live oak 19.4 60 50/35 Good vigor, fair form, codominant at 20 feet (Quercus agrifolia) with poor union, recommended to prune and cable.

31 Coast live oak 7.5 50 30/15 Fair vigor, fair form, suppressed. (Quercus agrifolia)

32 Black walnut 12.0 60 45/25 Fair vigor, fair form.
(Juglans nigra)

33 Bay 8.0 50 30/15 Fair vigor, fair form, suppressed. (Umbellularia californica)

34 Bay 9.0 50 30/15 Fair vigor, fair form, suppressed. (Umbellularia californica)

35 Bay 10.0 50 45/20 Fair vigor, fair form, suppressed. (Umbellularia californica)

36P Coast live oak 24.8 60 55/40 Fair vigor, fair form, heavy lean, on creek (Quercus agrifolia) bank, crown reduction pruning
recommended.

37R Red willow 6-3 0 20/12 DEAD.
(Salix laevigata)

38P Coast live oak 34.3 70 55/50 Good vigor, fair form. (Quercus agrifolia)

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575 Los Trancos (5)
Survey:

Tree# Species DBH CON HT/SP Comments
39 Big leaf maple 29.2 30 50/45 Poor vigor, poor form, large leader failure in (Acer macrophyllum) past, in decline.

40 Bay 10-12 55 40/30 Fair vigor, fair form, on creek bank, (Umbellularia californica) codominant at grade.

41 Bay 8-10 55 40/20 Fair vigor, fair form, suppressed, on creek (Umbellularia californica) bank.

42 Red willow 16.3 30 30/15 Poor vigor, poor form, heavy decay on trunk, (Salix laevigata) in decline.

43R Olive 42.1 20 30/25 Poor vigor, poor form, in decline, nearly (Olea europaea) dead.

44R Olive 30.2 20 30/25 Poor vigor, poor form, in decline, nearly (Olea europaea) dead.

45R Black walnut 12.6 65 30/25 Good vigor, good form.
(Juglans nigra)

46P Coast live oak 33.5 50 60/50 Fair vigor, fair form, decay at root crown, (Quercus agrifolia) recommended to expose root crown and inspect.

47P/R Coast live oak 36.0 0 50/60 DEAD
(Quercus agrifolia)

48P Coast live oak 36.0 10 15/15 Fair vigor, poor form, failed tree, stump re (Quercus agrifolia) sprout.

49P Coast live oak 29.8 70 50/40 Good vigor, good form, dense canopy. (Quercus agrifolia)

50*P Coast live oak 30est 80 45/40 Good vigor, good form. (Quercus agrifolia)

51P Coast live oak 16.2 65 30/20 Good vigor, fair form, suppressed. (Quercus agrifolia)

52P Coast live oak 10-8 65 30/20 Good vigor, fai form, suppressed. (Quercus agrifolia)

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575 Los Trancos (6)
Survey:

Tree# Species DBH CON HT/SP Comments
53 Coast live oak 11.1 50 20/30 Good vigor, poor form, suppressed, leans. (Quercus agrifolia)

54P Coast live oak 16.2 60 35/30 Good vigor, poor form, suppressed, leans. (Quercus agrifolia)

55 Bay 66.0 40 70/40 Fair to poor vigor, poor form, multi leader at (Umbellularia californica) 5 feet, ganoderma fungus at base, recommended to prune out dead wood,
and test for extent of decay.

56 Bay 10-6-9-7-10-4-4-11 50 50/30 Fair vigor, poor form, multi at base. (Umbellularia californica)

57 Bay 13-12-6 50 45/30 Fair vigor, poor form, multi at base. (Umbellularia californica)

58 Bay 6.0 40 30/15 Fair vigor, poor form, suppressed. (Umbellularia californica)

59 Bay 28.6 50 60/30 Fair vigor, fair form, codominant at 8 feet. (Umbellularia californica)

60 Redwood 8.1 80 25/10 Good vigor, good form, recently planted. (Sequoia sempervirens)

61 Redwood 6.4 80 18/10 Good vigor, good form, recently planted. (Sequoia sempervirens)

62 Redwood 10.3 80 18/10 Good vigor, good form, recently planted. (Sequoia sempervirens)

63 Redwood 5.1 80 18/10 Good vigor, good form, recently planted. (Sequoia sempervirens)

64 Redwood 5.5 80 18/10 Good vigor, good form, recently planted. (Sequoia sempervirens)

65 Redwood 9.2 80 18/10 Good vigor, good form, recently planted. (Sequoia sempervirens)

66 Redwood 8.3 80 18/10 Good vigor, good form, recently planted. (Sequoia sempervirens)
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575 Los Trancos (7)
Survey:

Tree# Species DBH CON HT/SP Comments
67 Redwood 6.7 80 18/10 Good vigor, good form, recently planted. (Sequoia sempervirens)

68 Redwood 9.9 80 18/10 Good vigor, good form, recently planted. (Sequoia sempervirens)

69 Redwood 5.5 80 18/10 Good vigor, good form, recently planted. (Sequoia sempervirens)

70 Bay 7-25-10-13-18-30-17 50 20/35 Fair to poor vigor, poor form, multi leader at (Umbellularia californica) grade.

71 White alder 24.2 45 60/25 Fair vigor, poor form, suppressed, leans (Alnus rhombifolia) against bay tree.

72 Coast live oak 10.1 60 45/25 Fair vigor, fair form, suppressed. (Quercus agrifolia)

73 Coast live oak 8.6 60 45/25 Fair vigor, fair form, suppressed. (Quercus agrifolia)

74 Coast live oak 5.1 50 18/12 Fair vigor, poor form, suppressed. (Quercus agrifolia)

75 Coast live oak 5.3 50 15/12 Fair vigor, poor form, suppressed. (Quercus agrifolia)

76 Elderberry 8-7 20 25/20 Poor vigor, poor form.
(Sambucus nigra)

77 Black walnut 5.0 60 40/15 Good vigor, fair form.
(Juglans nigra)

78 Bay 13-14-11 50 45/35 Fair vigor, poor form, multi leader at grade. (Umbellularia californica)

79 Bay 8.0 30 20/10 Fair vigor, poor form, topped for utilities, (Umbellularia californica) next to driveway.

80P Coast live oak 25.8 45 25/35 Good vigor, poor form, topped for utilities, (Quercus agrifolia) next to driveway.

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575 Los Trancos (8)
Survey:

Tree# Species DBH CON HT/SP Comments
81P Coast live oak 13.3 45 20/15 Fair vigor, poor form, topped for utilities. (Quercus agrifolia)

82 Buckeye 8.0 45 18/12 Fair vigor, poor form, under utilities, poor (Aesculus californica) location, grows towards road.

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575 Los Trancos (9)

Showing tree locations

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575 Los Trancos (10)

Non-protected trees to be removed:

Red willow tree #37 is dead and should be removed as soon as possible as it is hazardous and a fire hazard for the site.

Olive trees #43 and #44 are in very poor condition.

These trees are expected to be dead within the next
few months. The trees are within the proposed
driveway area. Tree removal and replacement is
recommended. Black walnut tree #45 is in fair
condition. This tree is also proposed for remova l to
facilitate the proposed construction of the driveway.

Showing nearly dead olive trees #43 and #44

Protected trees proposed for removal:

Coast live oak tree #47 is dead. The tree
should be removed as soon as possible as it is
a fire hazard for the site.

Showing oak tree #47

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575 Los Trancos (11)

Tree replacement measures:

The tree canopy replacement standard as seen in Palo Alto’s Tree Technical Manual was used to establish the number of replacement trees required on site. Below is a list of the canopy distance for each tree to be removed followed by the number of replacement trees required to fulfill city requirements.

Red Willow #37=12’ wide canopy
Replacement trees= The tree is dead. No replacement trees are recommended.

Olive tree #43= 25’ wide canopy
Replacement trees= Three 24” box size trees or two 36” box trees

Olive tree #44= 25’ wide canopy
Replacement trees= Three 24” box size trees or two 36” box trees

Black walnut tree #45= 25’ wide canopy
Replacement trees= Three 24” box size trees or two 36” box trees

Coast live oak tree #47= 60’ wide canopy
Replacement trees= The tree is dead. No replacement trees are recommended.

Showing tree canopy replacement standard used
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Summary of retained trees:

Many large mature native oak trees were observed
on site. Between the home and the proposed
building pad are where the larger oak trees exist.

These trees have grown in a grove like fashion
with trees developing leans and heavy lateral
limbs. Crown reduction pruning and cabling of
codominant leaders is recommended for many of
the larger oak trees on site. These
recommendations can be seen in bold within the
survey portion of the report. Oak trees #20, 22,
and 46 are recommended to have their root crowns
exposed and inspected as signs of possible root rot
disease were observed. A large ganoderma fungus
and dead wood was observed on the root crown of
bay tree #55. A drill test and root crown is
exposure is recommended to explore the extent of
decay at the root crown. A general crown
cleaning to remove dead wood is recommended
for the oak trees to be retained as little to no tree
Showing large oaks on site maintenance has taken place on the site. The retained oak trees are recommended to be annually
inspected by a Certified Arborist for any needed
work. The area underneath the dripline of the
retained oak trees is recommended to maintain a
dry landscape.

Impacts/Recommendations:

Preliminary site plan A1.1 was reviewed for writing this section of the report. The retained trees are all a fair distance away from the proposed work on site. Oak tree #3 is shown at 13 feet from the proposed driveway. Oak tree #4 is shown at 21 feet from the secondary driveway. The driveway is shown on a sloped area. It is recommended to use a retaining wall to reduce any grading needed on the tree side of the secondary driveway and main driveway when near oak trees #3 and #4. This will help to reduce impacts as much as possible due to the grading that would be needed if the driveway was to be built without a retaining wall. Excavation for the retaining wall is recommended to be done by hand while under the Project Arborist supervision when working within 10 times the diameter of the protected trees on site. Roots encountered will need to be cleanly cut. Cut root ends will need to be kept moist by covering the cut root ends with layers of wetted down burlap. A soaker hose is recommended to be installed at the retaining wall cut once the retaining wall has been built. The soaker hose is recommended to be turned on every week during the first dry season following the retaining wall build. After one year the soaker hose shall be permanently suspended. The two oak trees will need to be inspected monthly during the required monthly inspections during the proposed construction.

Once construction has been completed, the trees are recommended to be inspected annually in the spring. Impacts are expected to be minor.

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575 Los Trancos (13)
Coast Live Oak tree #3 is the closest tree to the proposed driveway. At 10 times the tree’s diameter the tree protection zone radius is 32.75 feet or a 3370 square foot area. The proposed driveway and retaining wall overlaps this area by 838 square feet. The tree’s root zone will be encroached by 24.9% as shown in the provided diagram below. This is within Best Management Practices acceptable threshold for a species with a good tolerance to construction impacts and in good condition (or 25%). The recommendations stated in the last paragraph will help to keep impacts at a minor level. This tree is also recommended to be deep water fertilized anytime between fall and early spring.

Showing percentage of root zone impacted for Oak tree #3

The proposed driveway follows the same direction of the existing driveway near oak trees #1 and #2. Excavation for the new driveway when within the dripline of oak trees #1 and #2 shall not exceed more than 8” under existing grade. The finished grade of the driveway near these two trees is recommended to be at the existing grade or higher up. This will help to reduce impacts to the trees. Roots encountered measuring 2” in diameter or larger will need to be retained within the base rock section by packing base rock around roots. The existing driveway near these trees my have helped to reduce root growth in the area of proposed work through compaction. All excavation underneath the dripline of a protected tree will need to be carried out by hand while under the direct supervision of the Project Arborist.

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A building wall is located at 11 feet from oak tree #30. Hand excavation under the Project Arborist supervision is recommended when working within 10 times the tree’s diameter.

Encountered roots must be cleanly cut using a hand saw or loppers. Once the wall has been built a soaker hose is recommended to be installed at the wall cut. The soaker hose is recommended to be turned on every week during the first dry season following the wall build. After one year the soaker hose shall be permanently suspended. The oak tree will need to be inspected monthly during the required monthly inspections during the proposed construction. Once construction has been completed, the tree is recommended to be inspected annually in the spring.

Tree Protection Plan:

Tree protection zones should be established and maintained throughout the entire length of the project. Fencing for the protection zones should be 6-foot-tall metal chain link type supported by 2-inch diameter metal poles pounded into the ground to a depth of no less than 2 feet. The support poles should be spaced no more than 10 feet apart on center. The location for the protection fencing for the protected trees on site should be placed at the tree driplines where possible (type 1 tree protection fencing). All other non-protected trees are recommended to be protected by fencing placed at the dripline as well. No equipment or materials should be stored or cleaned inside protection zones. Signs should be placed on fencing signifying “Tree Protection Zone - Keep Out”. If fencing needs to be reduced for access or any other reasons, the non-protected areas must be protected by a landscape buffer.

All tree protection and inspection schedule measures, design recommendations, watering and construction scheduling shall be implemented in full by the owner and contractor.

Showing type 1 tree protection fencing
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575 Los Trancos (15)

Landscape Buffer
Where tree protection does not cover the entire root zone of the trees at the dripline or when a smaller tree protection zone is needed for access, a landscape buffer consisting of wood chips spread to a depth of six inches with plywood or steel plates placed on top will be placed where foot traffic is expected to be heavy. The landscape buffer will help to reduce compaction to the unprotected root zone. If plywood is used the pieces of plywood shall be attached in a way that minimizes movement.

Tree Pruning
During construction any Pruning will be supervised by the site arborist and must stay underneath 25% of the tree total foliage.

Root Cutting
Any roots to be cut should be monitored and documented. Large roots or large masses of roots to be cut should be inspected by the site arborist. The site arborist may recommend irrigation or fertilizing at that time. Cut all roots clean with a saw or loppers. Roots to be left exposed for a period of time should be covered with layers of burlap and kept moist. Roots to be cut measuring larger than 1.5” in diameter shall be shown to the Project Arborist before being cut.

Trenching and Excavation
Trenching for irrigation, electrical, drainage or any other reason, should be located outside of the trees calculated root zone of 10 times the tree diameters when possible. If not possible, trenching shall be hand dug when beneath the dripline of desired trees. Any excavation underneath the dripline of a protected tree will need to be supervised by the Project Arborist. Hand digging and careful placement of pipes below or beside protected roots will dramatically reduce root loss, thus reducing trauma to desired trees. Trenches should be back filled as soon as possible using native materials and compacted to near original levels. Trenches to be left open with exposed roots shall be covered with burlap and kept moist. Plywood laid over the trench will help to protect roots below. Roots retained within trenches are recommended to be wrapped in layers of wetted down burlap to avoid root desiccation.

Irrigation
Normal irrigation should be maintained throughout the entire length of the project for the imported trees. Irrigation should consist of surface flooding, with enough water to wet the entire root zone every other week during the dry season. The native trees on site (oaks, bays, and buckeyes) shall only be irrigated during the months of May and September to combat a prolonged drought period, or if their root zones are traumatized.

Grading
All existing grades underneath the dripline of a protected tree shall remain as is where possible.

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Inspections
The site will be inspected after the tree protection measures are installed and before the start of construction. Monthly inspections are mandatory for a site such as this. Inspections will be carried out during the first week of each month. The inspections will be documented with inspection letters being provided to the owner, contractor, and City Arborist. Other inspections will be carried out on an as needed basis. The monthly inspections are required by the city of Palo Alto as a condition of approval. It is the contractor’s responsibility to notify the site arborist when construction is to start, and whenever there is to be work performed within the dripline of a protected tree on site at least 48 hours in advance. During the site visits the site arborist will offer mitigation measures specific to the work completed. Kielty Arborist Services can be reached at 650-515-9783 or 650-532-4418, or by email at [email protected]. A final inspection letter will also be required by the city before final occupancy.

Further information about tree protection can be found in the Tree Technical Manual provided by the city of Palo Alto. This information should be kept on site at all times. The information included in this report is believed to be true and based on sound arboricultural principles and practices.

Sincerely,
Kevin R. Kielty Certified Arborist WE#0476A

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Kielty Arborist Services
P.O. Box 6187
San Mateo, CA 94403
650-515-9783

ARBORIST DISCLOSURE STATEMENT
Arborists are tree specialists who use their education, knowledge, training and experience to examine trees, recommend measures to enhance the beauty and health of trees, and attempt to reduce the risk of living near trees. Clients may choose to accept or disregard the recommendations of the arborist, or seek additional advice.

Arborists cannot detect every condition that could possibly lead to the structural failure of a tree. Trees are living organisms that fail in ways we do not fully understand. Conditions are often hidden within trees and below ground. Arborists cannot guarantee that a tree will be healthy or safe under all circumstances, or for a specified period of time. Likewise, remedial treatments, like a medicine, cannot be guaranteed.

Treatment, pruning, and removal of trees may involve considerations beyond the scope of the arborist’s services such as property boundaries, property ownership, site lines, disputes between neighbors, landlord-tenant matters, etc. Arborists cannot take such issues into account unless complete and accurate information is given to the arborist. The person hiring the arborist accepts full responsibility for authorizing the recommended treatment or remedial measures.

Trees can be managed, but they cannot be controlled. To live near a tree is to accept some degree of risk. The only way to eliminate all risks is to eliminate all trees.

Arborist: ____________________________
Kevin R. Kielty
Date: August 24
th, 2021
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Appendix C
Geotechnical Engineering Study
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April 9, 2021  File No.:  304309‐001

Mr. John Suppes
Clarum Homes
P.O. Box 60970
Palo Alto, CA 94306

PROJECT:  PROPOSED SINGLE FAMILY RESIDENCE and ADU
575 LOS TRANCOS ROAD
PALO ALTO, CALIFORNIA

SUBJECT:  Geotechnical Engineering Study

REF.:  Revised  Proposal  to  Perform  a  Geotechnical  Engineering  Study  and Liquefaction Analysis, Proposed
Single Family Residence and ADU, 575
Los Trancos Road, Palo Alto, California, by Earth Systems Pacific, dated November 20, 2020, revised December 4, 2020.

Soil  Investigation,  Proposed  Single‐Family  Residence,  Los  Trancos Property  (APN  182‐46‐003),  Palo  Alto,  California,  by  Harding  Lawson Associates, dated January 26, 1990.

Dear Mr.

Suppes:

In  accordance  with  your  authorization  of  the  above  referenced  proposal,  this  geotechnical engineering  study  has  been  prepared  by  Earth  Systems  Pacific  (Earth  Systems)  for  use  in  the development of plans and specifications for the proposed single family residence and accessory dwelling unit (ADU) in Palo Alto, California.  Preliminary geotechnical recommendations for site preparation and grading; foundations; slabs‐on‐grade; exterior flatwork; swimming pool; utility trench backfill; site drainage and finish improvements; and observation and testing are presented herein.

We appreciate the opportunity to have provided services for this project and look forward to working with you again in the future.  Please do not hesitate to contact this office if there are any questions concerning this report.

Sincerely,

Earth Systems Pacific

Phillip Penrose   Bill Zehrbach, GE 926
Staff Engineer   Principal Engineer
Doc. No.:  2104‐004.SER/kt
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TABLE OF CONTENTS
Page

1.0  INTRODUCTION ................................................................................................ 1 Site Setting ...........................................................................................................  1 Site Description ....................................................................................................  1 Planned Development ..........................................................................................  1 Scope of Services ..................................................................................................  1

2.0  GEOLOGIC SETTING .......................................................................................... 2

3.0  FIELD INVESTIGATION AND LABORATORY TESTING .......................................... 3 Previous Geotechnical Studies ............................................................................. 3 Subsurface Exploration (Current) ......................................................................... 3 Subsurface Profile ................................................................................................  4 Laboratory Testing ...............................................................................................  4

4.0  DATA ANALYSIS ................................................................................................ 5 Subsurface Soil Classification ............................................................................... 5 Seismic Design Parameters ...................................................................................  5 Static Settlement ..................................................................................................  5 Liquefaction ..........................................................................................................  5

5.0  CONCLUSIONS .................................................................................................. 7 Site Suitability .......................................................................................................  7 Soil Expansion Potential .......................................................................................  7 Foundations .........................................................................................................  7 Site Preparation and Grading ............................................................................... 7 Groundwater ........................................................................................................  7 Seismicity .............................................................................................................  8

6.0  RECOMMENDATIONS ....................................................................................... 8 Site Preparation and Grading ............................................................................... 8 Foundations .........................................................................................................  10 Interior Slab‐on‐Grade Construction .................................................................... 11 Exterior Flatwork ..................................................................................................  12 Swimming Pool .....................................................................................................  13 Utility Trench Backfills ..........................................................................................  13 Management of Site Drainage and Finish Improvements .................................... 14 Geotechnical Observation and Testing ................................................................. 15

7.0  CLOSURE .......................................................................................................... 16

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TABLE OF CONTENTS (CONT.)

FIGURES
Figure 1 – Site Location Map
Figure 2 – Site Plan
APPENDIX A
Boring Logs
Harding Lawson Associates
1990
APPENDIX B
Logs of Test Borings
Earth Systems Pacific
2021
APPENDIX C
Summary of Laboratory Test Re
sults
APPENDIX D
Liquefaction Analysis
Dry Sand Settlement
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1.0 INTRODUCTION
Site Setting
The subject property is an irregular shaped, 5.47‐acre parcel located at 575 Los Trancos Road in Palo Alto, California (APN 182‐46‐012).  The site has a latitude of 37.3666°N and a longitude of 122.2012°W.  The general location of the site is shown on the Site Location Map (Figure 1).

Site Description
The subject property is located on the west side of Los Trancos Road, about a half mile south of the intersection of Los Trancos Road and Alpine Road.  The property is bounded by Los Trancos Road to the east, Los Trancos Creek and Valley Oak Street to the west, an existing residence to the north and undeveloped land to the south.

The property is currently undeveloped.  The center of the parcel is covered with grasses and the property  borders  are  covered  by  trees  and  dense  brush.   Los  Trancos  Creek  runs  along  the western edge of the property.   An existing gravel road starts at the northeastern corner of the property off Los Trancos Road and grants access to the property and the neighboring property to the north.   The center of the lot, where the proposed developments lie, is mostly flat.   The lot slopes towards the creek on the west side and slopes upwards towards Los Trancos Road on the east side.

Planned Development
We understand that you plan to construct a new residence in approximately the center of the parcel.  The proposed ADU is expected to be constructed on the southern portion of the parcel and
the swimming pool is proposed on the southwestern portion of the parcel.  See Figure 2, Site Plan.   Based on the preliminary plans by LNAI Architecture (dated February 10, 2021), it is our understanding that the new residence will be a two‐story building with a partial second story.

Scope of Services
The scope of work for the geotechnical engineering study included a general site reconnaissance, evaluation of the subsurface soil and groundwater conditions from a geotechnical engineering standpoint by drilling borings and laboratory testing of selected samples, engineering analysis of the  collected  data,  and  preparation  of  this  report.   The  analysis  and  subsequent recommendations were based on our understanding of the proposed development at the subject site.

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The  report  and  recommendations  are  intended  to  comply  with  the  considerations  of  Section 1803 of the California Building Code (CBC), 2019 Edition, and common geotechnical engineering practice in this area at this time under similar conditions.  The tests were performed in general conformance with the standards noted, as modified by common geotechnical practice in this area at this time under similar conditions.

Preliminary geotechnical recommendations for site preparation and grading, foundations, slabs‐ on‐grade,  exterior  flatwork,  swimming  pool,  utility  trench  backfill,  site  drainage  and  finish improvements,  and  geotechnical  observation  and  testing  are  presented  to  guide  the development of project plans and specifications.  It is our intent that this report be used by the client to form the geotechnical basis of the design of the project as described herein, and in the preparation of plans and specifications.

Detailed evaluation of the site geology and potential geologic hazards, and analyses of the soil for  mold  or  other  microbial  content,  asbestos,  percolation  rates,  corrosion  potential, radioisotopes, hydrocarbons, or other chemical properties are beyond the scope of this report.

This report also does not address issues in the domain of contractors such as, but not limited to, site  safety,  loss  of  volume  due  to  stripping  of  the  site,  shrinkage  of  soils  during  compaction, excavatability, shoring, temporary slope angles, and construction means and methods.  Ancillary features such as swimming pools, temporary access roads, fences, light poles, and non‐structural fills are not within our scope and are also not addressed.

To verify that pertinent issues have been
addressed and to aid in conformance with the intent of
this report, it is requested that final grading and foundation plans be submitted to this office for review.   In  the  event  that  there  are  any  changes  in  the  nature,  design,  or  locations  of improvements, or if any assumptions used in the preparation of this report prove to be incorrect, the conclusions and recommendations contained herein should not be considered valid unless the changes are reviewed, and the conclusions of this report are verified or modified in writing by the Geotechnical Engineer.   The criteria presented in this report are considered preliminary until such time as they are verified or modified in writing by the Geotechnical Engineer in the field during construction.

2.0  GEOLOGIC SETTING
According to the Geologic Map of the Palo Alto 30’ x 60’ Quadrangle, California (Brabb et. al, 2000), the site is mapped as being underlain by Pleistocene older alluvial fan deposits (Qpoaf).

The site is located in a liquefaction hazards zone as delineated by the State of California and the County of Santa Clara.

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The entire San Francisco Bay Area is considered to be an active seismic region due to the presence of several active faults.  Three northwest‐trending major earthquake faults that are responsible for the majority of the movement on the San Andreas fault system extend through the Bay Area.

They  include  the  San  Andreas  fault,  the  Hayward  fault  and  the  Calaveras  fault,  which  are respectively located approximately 0.4 miles to the southwest, 19.3 miles to the northeast and

22.4 miles to the northeast.  The Monte Vista‐Shannon fault is located approximately 1.4 miles northeast of the site.  Using information from recent earthquakes, improved mapping of active faults, and  a new model for estimating earthquake probabilities, the 2014 Working Group on California Earthquake Probabilities updated the 30 year earthquake forecast for California.  They concluded  that  there  is  a  72  percent  probability  (or  likelihood)  of  at  least  one  earthquake  of magnitude  6.7  greater  striking  somewhere  in  the  San  Francisco  Bay  region  before  2043.   A summary of the significant faults in the near vicinity of the site are listed below.

Major Active Faults

Fault  Distance from Site
(miles)
Probability of
Mw≥6.7 within 30
Years1
San Andreas  0.4 (SW)  6%
Monte‐Vista Shannon  1.9 (NE)  1%
Hayward  19.3 (NE)  21%
Calaveras  22.4 (NE)  7%
1 Working Group on California Earthquake Probabilities, 2015

3.0  FIELD INVESTIGATION AND LABORATORY TESTING
Previous Geotechnical Studies
Harding Lawson Associates prepared a Soil Investigation for the subject lot dated January 26, 1990.  Their investigation included the drilling of 5 exploratory borings on the lot at the approximate locations indicated on Figure 2, Site Plan.  The logs of these borings are presented in Appendix A.

Subsurface Exploration (Current)
The subsurface exploration for this study consisted of drilling two exploratory borings at the site on February 23, 2021.  The approximate locations of the test borings are shown on (Figure 2).

The borings were advanced to depths of 34 feet below ground surface (bgs).  The drilling process consisted  of  using  a  truck‐mounted  drilling  rig  equipped  with  8‐inch  diameter  hollow  stem augers.  Once reaching the desired depth, a standard Mod‐Cal or SPT sampler, connected to steel ITEM 13
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rods was lowered into the hole.  The samplers were driven into undisturbed ground with a 140‐ pound,  safety  hammer  falling  about  30  inches  per  drop.   The  samplers  were  driven  up  to  18 inches and the hammer blows required to drive every six inches of the samplers were recorded and are presented on the boring logs.  The number of blows required to drive the final 12 inches of the sampler into the undisturbed ground were used as Penetration Resistance and this was used to interpret soil consistency/density.   The borings were then backfilled with lean cement grout.  The boring logs show soil description including: color, major and minor components, USCS classification,  changes  in  soil  conditions  with  depth,  moisture  content,  consistency/density, plasticity, sampler type, and sampling depths and laboratory test results.  Copies of the logs of boring drilled for this investigation are presented in Appendix B.

Soils  encountered  in  the  borings  were  logged  in  general accordance  with  the  Unified  Soil
Classification System.   An Earth Systems engineer prepared the logs and retained samples for laboratory testing.

Subsurface Profile
The borings drilled at the site revealed the presence of loose to very dense sand with variable percentages  of  clay  and  gravel.   This  is  consistent  with  the  geological  mapping  by  Brabb  et al.(2000).   In  Boring  B‐1,  the  upper  5  feet  consisted  of  medium  dense  well  graded  sand  with gravel.  Below the well‐graded sand, a clayey sand layer with variable percentages of gravel was encountered  and  extended  to  the  bottom  of  the  boring  at  34  feet  bgs.   Some  cobbles  were encountered  in  the  boring  at  7  feet  bgs.   In  Boring  B‐2,  loose  clayey  sand  with  gravel  was encountered  at  the  surface  and  extended  to  17  feet  bgs.   The  sand  became  denser  at approximately 7 feet bgs.  At 17 feet bgs, a medium dense, well graded sand with clay and gravel layer was encountered.  The clay content increased at 23 feet and decreased again at 28 feet bgs to well graded sand with clay and gravel, which extended to the bottom of the boring at 34 feet bgs.

Groundwater  was  encountered  at  17  to  18  feet  bgs  in  the  borings  drilled  at  the  site  to  the maximum depth of exploration of 34 feet bgs.

Laboratory Testing
Five liner samples were tested to measure moisture content and dry density (ASTM D 2216‐17 and D 2937‐17), and four samples were tested to determine the percentage of material passing the minus #200 sieve (ASTM D 1140‐17).   Copies of the laboratory test results are included in Appendix C.

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4.0  DATA ANALYSIS
Subsurface Soil Classification
Based on the subsurface data collected as a part of our subsurface exploration and our review of the published geologic literature, the site is assigned to Site Class C (very dense soil and soft rock) as defined by Table 20.3‐1 of the ASCE 7‐16.

Seismic Design Parameters
The following seismic design parameters represent the general procedure as outlined in Section 1613 of the CBC and in ASCE 7.   The values determined below are based on the 2009 National Earthquake Hazard Reduction Program (NEHRP) maps and were obtained using the United States Geological Survey’s Design Maps Web Application.

Summary of Seismic Parameters ‐ CBC 2019
(Site Coordinates 37.3859°N, 122.1399°W)

Static Settlement
Based on our understanding of the proposed development and because the building loads are anticipated  to  be  fairly  light,  anticipated  static  settlements  are  on  the  order  of  1  inch  with  a differential settlement of ½ inch.

Liquefaction
Soil liquefaction is a phenomenon where saturated granular soils undergo a substantial loss of strength due to increased pore water pressure resulting from cyclic stress applications induced by earthquakes or other vibrations.  In this process, the soil acquires mobility sufficient to permit both vertical and horizontal movements, which may result in significant deformations.  Soils most Parameter  Design Value
Site Class  C
Mapped Short Term Spectral Response Parameter, (Ss)  2.549 Mapped 1‐second Spectral Response Parameter, (S1)  1.008 Site Coefficient, (Fa)  1.2
Site Coefficient, (Fv)  1.4
Site Modified Short Term Response Parameter, (SMs)  3.059 Site Modified 1‐second Response Parameter, (SM1)  1.411 Design Short Term Response Parameter, (SDs)  2.04
Design 1‐second Response Parameter, (SD1)  0.94
Seismic Design Category  E
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susceptible to liquefaction are loose, uniformly graded, fine‐grained sands.   In addition, recent literature indicates that fine grained soils may also be susceptible to liquefaction or cyclic strain softening.   Examples of highly susceptible fine‐grained soil include “non‐plastic silts and clayey silts of low plasticity (PI<12) at high water content to liquid limit ratios (wc/LL>0.85).”  Examples of soils moderately susceptible to liquefaction include “clayey silts and silty clays of moderate plasticity (12<PI<18) at natural water content and Liquid Limits ratios (wc/LL) greater than 0.80.” (Bray and Sancio, 2006).   It is generally acknowledged that liquefaction will not affect surface improvements if these deposits are located at a depth greater than 50 feet below the ground surface.   In  the  deeper  deposits,  the  greater  overburden  pressure  is  sufficient  to  prevent liquefaction effects from occurring.

Analysis Parameters
The referenced 1990 report by Harding Lawson Associates, gave a historic groundwater level of 8 feet bgs from an unknown reference, thus we used this value in our analysis.  It should be noted that  this  value  is  likely  conservative.   According  to  United  States  Geological  Survey’s  (USGS) Unified Hazard Tool, the predominant earthquake contributor is the San Andreas fault with mean magnitude using deaggregation of 7.8.  The liquefaction analysis was performed utilizing the peak ground  acceleration  of  1.16g  (PGAm)  based  on  the  Office  of  Statewide  Health  Planning  and Development Seismic Design Maps Web Application.  Any sand‐like deposit (Soil Behavior Type Index, Ic < 2.6) below the groundwater table was assumed to be potentially liquefiable.    The liquefaction analysis was based on the methodologies suggested by Idriss and Boulanger (2008 and 2014).   The loose sand layers above the water table are subject to dry sand settlement.  A two‐thirds reduction in the PGA was used for the dry sand settlement, thus a separate analysis is presented in Appendix D.

Analysis Results
The  calculated  seismically  induced  settlement  (liquefaction  and  dry  sand  settlement)  was calculated to be approximately 1 to 1.7 inches.  The liquefaction and dry sand analysis results are included in Appendix D.

Discussion
In  general,  there  is  a  high  potential  of  granular  deposits  to  liquefy  during  a  seismic  event.

Seismically induced settlements are expected to be on the order of 1.7 inches total or less and approximately 1 inch of differential settlement during a design level seismic event.

The  creek  at  the  rear  of  the  property  is  approximately  80  feet  from  the  building  and  is approximately 10 feet high.  Estimates of lateral displacement are approximately 10 inches at the site.  The zone of soil susceptible to liquefaction and lateral displacement are present at depths ITEM 13
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from 19 to 23 feet at Boring B‐1and appear to be at an elevation below the channel.  The zone of soil susceptible to liquefaction at Boring B‐2 is 8.5 to 13.5 feet bgs, indicating that the potentially liquefiable soils across the site are discontinuous.  This is consistent with the analysis results of Harding Lawson Associates.  As such, the potential for lateral displacement is considered low.

5.0  CONCLUSIONS
Site Suitability
The  subject  site  is  suitable  for  the  proposed  residential  improvements  from  a  geotechnical engineering standpoint, provided the recommendations included in this report are followed.  The primary geotechnical concerns at the
site are loose soils in the upper 5 feet and the settlement due to sesmic shaking.

Soil Expansion Potential
The near surface soils were sandy in nature and thus not deemed expansive.  Thus, no measures other than moisture conditioning the pad are deemed yesterday.

Foundations
Due to the settlement from sesmic shaking, the proposed loads of the residence and ADU may be supported on a either a mat slab foundation or a post‐tensioned slab foundation.  Details of the foundation recommendations are included in the following sections of the report.

Site Preparation and Grading
Due to the loose soil in the upper 5 feet, a program of over‐excavation is deemed necessary.  The upper  2½  feet  of  existing  ground  in  the  building  areas  should  be  over‐excavated  and recompacted.   Cuts  and  fills  to  create  the  pad  for  the  residence  are  expected  to  be  minimal.

Additional grading work is anticipated to include backfill work related to placement of new utility lines  and  construction  of  the  driveway,  patios,  and  pool  decking.   Grading  operations  are discussed in detail in the Recommendations section of this report.

Groundwater
Groundwater  was  encountered  at  approximately  17  to  18  feet  bgs  during  our  subsurface exploration.   Harding Lawson Associates reported
an historic high groundwater level of 8 feet
bgs.  Variations in rainfall, temperature, and other factors may affect water levels, and therefore groundwater levels should not be considered constant.  Groundwater is not expected to have an adverse  effect  on  the  construction  or  performance  of  the  proposed  residence  and  related structures.

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Seismicity
The  San  Francisco  Bay  area  is  recognized  by  geologists  and  seismologists  as  one  of  the  most seismically  active  regions  in  the  United  States.   The  significant  earthquakes  in  this  area  are generally  associated  with  crustal  movement  along  well‐defined,  active  fault  zones  which regionally trend in a northwesterly direction.   Although research on earthquake prediction has greatly increased in recent years, seismologists cannot predict when and where an earthquake will occur.  Nevertheless, on the basis of current technology, it is reasonable to assume that the proposed development will be subjected to at least one moderate to severe earthquake during its lifetime.  During such an earthquake, the danger from fault offset on the site is low, but strong shaking of the site is likely to occur and, therefore, the project should be designed in accordance with the seismic design provisions of the latest California Building Code.  It should be understood that  the  California  Building  Code  seismic  design  parameters  are  not  intended  to  prevent structural damage during an earthquake, but to reduce damage and minimize loss of life.

6.0  RECOMMENDATIONS
Site Preparation and Grading
General Site Preparation

1. The site should be prepared for grading by removing existing trees to be removed and their root systems, vegetation, debris, and other potentially deleterious materials from areas to receive improvements.  Existing utility lines that will not be serving the proposed residence should be either removed or abandoned.   The appropriate method of utility abandonment will depend upon the type and depth of the utility.  Recommendations for abandonment can be made as necessary.

2. Due to the loose surficial soil, a program of over‐excavation and backfilling is deemed necessary.  The upper loose soil within the area of the proposed improvements should be (over‐excavated to 2½ feet bgs.  The lateral extent of the over‐excavation should extend at least 5 feet beyond the perimeter of the proposed residence, ADU, driveway and pool decking  as  determined  in  the  field  by  the  Geotechnical  Engineer  during  grading operations.   The exposed ground should be reviewed by the Geotechnical Engineer to determine the need for additional excavation work.

3. Ruts or depressions resulting from the removal of tree root systems should be properly cleaned out down to undisturbed native soil.   The bottoms of the resulting depressions should be scarified and cross‐scarified at least 8 inches in depth, moisture conditioned
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and recompacted.  The depressions should then be backfilled with approved, compacted, moisture conditioned structural fill, as recommended in other sections of this report.

4. Site clearing, and backfilling operations, should be conducted under the field observation of the Geotechnical Engineer.  The Geotechnical Engineer should be notified at least 48 hours prior
to commencement of grading operations.

Compaction Recommendations

1. In  general,  the  underlying  native  soil  in  the  areas  proposed  to  receive  additional  fill, exterior  flatwork  or  new  structures  should  be  scarified  at  least  8  inches,  moisture conditioned  and  recompacted  to  the  recommended  relative  compaction  presented below, unless noted otherwise.

2. Recompacted  native  soils  and  fill  soils  should  be  compacted  to  a  minimum  relative compaction  of  90  percent  of  maximum  dry  density  at  a  moisture  content  at  least  2 percentage points above optimum.

3. In  areas  to  be  paved,  the  upper  8  inches  of  subgrade  soil  should  be  compacted  to  a minimum 92 percent of maximum dry density at a
moisture content at least 2 percentage
points above optimum.  The aggregate base courses should be compacted to a minimum 95 percent of maximum dry density at a moisture content that is slightly over optimum.

The  subgrade  and  base  should  be  firm  and  unyielding  when  proof‐rolled  with  heavy, rubber‐tired  equipment  prior  to  paving.   The  pavement  subgrade  soils  should  be frequently moistened as necessary prior to placement of the aggregate base to maintain the soil moisture content near optimum.

Fill Recommendations

1. Structural fill is defined herein as a native or import fill material which, when properly compacted, will support foundations, pavements, and other fills.  The on‐site native soils that are free of debris, organics and other deleterious material, may be used as structural fill.

2. Import fill is not anticipated
at the site.   Should import fill be required, the soil should meet the following criteria:
a.  Be  coarse  grained  and  have  a  plasticity  index  of  less  than  12  and/or  an expansion index less than 20;
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b.  Be free of organics, debris or other deleterious material; c.  Have a maximum rock size of 3 inches; and
d.  Contain  sufficient  clay  binder  to  allow  for  stable  foundation  and  utility trench excavations.

3. A sample of the of the soil proposed to be imported to the site should be submitted at
least three days before being transported to the site for evaluation by the geotechnical engineer.  During importation to the site the material should be further reviewed on an intermittent basis.

Foundations
Mat Slab Foundation

1. The  proposed  residence  and  ADU  may  be  supported  by  a  concrete  mat  foundation bearing on the native soil.  The mat slab should be designed using a maximum localized allowable  bearing  pressure  of  2,000  psf  for  dead  plus  live  load.   This  value  may  be increased by one‐third when transient loads such as wind or seismicity are included.  The mat slab should be sufficiently thick to uniformly spread the concentrated loads imposed by  any  building  columns.   The  mat  should  be  designed  using  a  modulus  of  subgrade reaction value of 125 psi per inch.   The slab should be designed for an edge cantilever distance of 6 feet and an interior span condition of 10 feet.

2. The mat slab should be thickened at the edges to penetrate a minimum of 6 inches into the prepared subgrade for a minimum width of 2 feet.  The mat slab should be placed on top of a vapor retarder and capillary break layer extending to the thickened edge along the perimeter.

3. Resistance  to  lateral  loads  should  be  calculated  based  on  a  passive  equivalent  fluid pressure of 300 pcf and a friction factor of 0.3.

Post‐Tensioned Slab Foundation

1. The  post‐tensioned  slabs  should  be  designed  in  accordance  with  the  provisions  of  the current  edition  of  the  California  Building  Code  and  the  recommendations  of  the  Post‐ Tensioning  Institute.   Values  for  Edge  Moisture  Variation  Distance  and  Estimated Differential Swell were calculated in accordance with the third edition of Design of Post‐ Tensioned Slabs‐on‐Ground by the Post‐Tensioning Institute (2008).

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Edge Moisture Variation Distance (em)
Center Lift Condition   9.0 feet
Edge Lift Condition   5.0 feet
Estimated Differential Swell (ym)
Center Lift Condition   0.5 inches
Edge Lift Condition   0.8 inches
Allowable Bearing Capacity (dead load)  1,500 psf
Allowable Bearing Capacity (dead + live loads)  2,000 psf Allowable Bearing Capacity (DL+LL+ wind or seismic)  2,500 psf Subgrade Friction Factor (slab against subgrade)  0.3
Total settlement (static)  < 1 inch
Differential settlement (static)  < 0.5 inches

2. To  further  protect  moisture‐sensitive  floor  coverings,  the  perimeters  of  the  post‐ tensioned  slabs  should  be  deepened  to  penetrate  a  minimum  of  6  inches  into  the subgrade soil.   Also, the concrete could be proportioned to reduce its porosity (and its corresponding  potential  for  transmitting  moisture)  by  limiting  the  w/c  ratio  to  0.48  or less.

3. Post‐tensioned  slabs  should  be  constructed  and  maintained  in  accordance  with  the publication  Construction  and  Maintenance  Manual  for  Post‐Tensioned  Slab‐on‐Ground Foundations by the Post‐Tensioning Institute.  Particular attention should be paid to the “Property Owner Maintenance” and “Landscaping” sections of the Manual.

Interior Slab‐on‐Grade Construction

4. The building pad should be periodically moisture conditioned as necessary to maintain the soil moisture content at a minimum of 2 percent above optimum until the placement of concrete or vapor retarding membranes.  The moisture content of the soil should be verified  by  the  Geotechnical  Engineer  prior  to  placement  of  the  concrete  or  vapor retarding membranes.

5. In areas where moisture transmitted from the subgrade would be undesirable, a vapor retarder underlain by a capillary break consisting of 4 inches of crushed rock should be utilized beneath the floor slab.   The vapor retarder should comply with ASTM Standard Specification  E  1745‐17  and  the  latest  recommendations  of  ACI  Committee  302.   The vapor retarder should be installed in accordance with ASTM Standard Practice E 1643‐ 18a.  Care should be taken to properly lap and seal the vapor retarder, particularly around utilities, and to protect it from damage during construction.  A sand layer above the vapor retarder is optional.

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6. If sand, gravel or other permeable material is to be placed over the vapor retarder, the material over the vapor retarder should be only lightly moistened and not saturated prior to casting the slab.  Excess water above the vapor retarder would increase the potential for  moisture  damage  to  floor  coverings.   Recent  studies,  including  those  by  ACI Committee  302,  have  concluded  that  excess  water  above  the  vapor  retarder  would increase  the  potential  for  moisture  damage  to  floor  coverings  and  could  increase  the potential  for  mold  growth  or  other  microbial  contamination.   These  studies  also concluded  that  it  is  preferable  to eliminate  the  sand  layer and  place  the  slab  in  direct contact with the vapor retarder, particularly during wet weather construction.  However, placing  the  concrete  directly  on  the  vapor  retarder  would  require  special  attention  to using the proper vapor retarder, concrete mix design, and finishing and curing techniques.

7. When concrete slabs are in direct contact with vapor retarders, the concrete water to cement  (w/c)  ratio  must  be  correctly  specified  to  control  bleed  water  and  plastic shrinkage and cracking.  The concrete w/c ratio for this type of application is typically in the range of 0.45 to 0.50.  The concrete should be properly cured to reduce slab curling and  plastic  shrinkage  cracking.   Concrete  materials,  placement,  and  curing  methods should be specified by the architect/engineer.

Exterior Flatwork

1. Exterior  flatwork  should  have  a  minimum  thickness  of  4  full  inches  and  should  be reinforced  as  directed  by  the  architect/engineer.   Patio  slabs  and  walkways  should  be underlain by
a minimum 4 inches of compacted aggregate base over properly compacted subgrade soil.

2. Assuming  that  movement  (i.e.,  1/4‐inch  or  more)  of  exterior  flatwork  beyond  the structure is acceptable, the flatwork should be designed to be independent of the building foundations.  The flatwork should not be doweled to foundations, and a separator should
be placed between the two.

3. To reduce shrinkage cracks in concrete, the concrete aggregates should be of appropriate size  and  proportion,  the  water/cement  ratio  should  be  low,  the  concrete  should  be properly  placed  and  finished,  contraction  joints  should  be  installed,  and  the  concrete should be properly
cured.  Concrete materials, placement and curing specifications should be at the direction of the designer; ACI 302.1R‐04 and ACI 302.2R‐04 are suggested as resources for the designer in preparing such specifications.

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Swimming Pool

1. The swimming pool design should be based on a minimum soil equivalent fluid pressure of  45  pcf.   To  reduce  the  potential  for  future  expansion,  the  soil  exposed  in  the  pool excavation should be kept in a moist condition prior to placement of the gunite.

2. The pool may
be designed with a pressure relief valve. The necessity of the valve should be under the discretion of the pool designer.

3. The pool excavation should be observed by a representative from Earth Systems. If soft soils or other unanticipated conditions are observed in the excavation, compaction of the soil
or other remedial measures may be recommended.  Recommendations for remedial grading or other measures (if deemed necessary) should be provided by the Geotechnical Engineer based on the conditions observed at the time of construction.

4. Any portions of the pool shell that will be above ground should be designed to support

the  water  in  the  pool  without  soil  support  in  accordance  with  Section  1808.7.3  of  the California Building Code.

5. If portions of the pool walls will be within a horizontal distance of 7 feet from the top of an adjacent slope, those portions of the wall should be capable of supporting the water
in the pool without soil support per section 1808.7.3 of the California Building Code.

Utility Trench Backfills

1. A select, noncorrosive, granular, easily compacted material should be used as bedding and  shading  immediately  around  utility  pipes.   The  site  soils  may  be  used  for  trench backfill above the select
material.

2. Trench  backfill  in  the  upper  8  inches  of  subgrade  beneath  pavement  areas  should  be compacted to a minimum of 92 percent of maximum dry density at a moisture content at least  2  percentage  points  above  optimum  moisture  content  and  the  aggregate  base courses  should  be  compacted  to  a  minimum  95  percent  of  maximum  dry  density  at  a moisture content  at  least  2  percentage  points  over  optimum.   Trench backfill  in  other areas should be compacted to a minimum of 90 percent of maximum dry density at a moisture content at least 2 percentage points above optimum moisture content.  Jetting of utility trench backfill should not be allowed.

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3. Where  utility  trenches  extend  under  perimeter  foundations,  the  trenches  should  be backfilled  entirely  with  approved  fill  soil  compacted  to  a  minimum  of  90  percent  of maximum dry density at a moisture content at least 2 percentage points above optimum moisture content.  The zone of approved fill soil should extend a minimum distance of 2 feet on both sides of the foundation.   If utility pipes pass through sleeves cast into the perimeter foundations, the annulus between the pipes and sleeves should be completely sealed.

4. Parallel trenches excavated in the area under foundations defined by a plane radiating at a 45‐
degree angle downward from the bottom edge of the footing should be avoided, if possible.   Trench  backfill  within  this  zone,  if  necessary,  should  consist  of  Controlled Density Fill (Flowable Fill).

Management of Site Drainage and Finish Improvements

1. Unpaved ground surfaces should be finish graded to direct surface runoff away from site improvements at a minimum 5 percent grade for a minimum distance of 10 feet.  If this is not practical due to the terrain or other site features, swales with improved surfaces should be provided to divert drainage away from improvements.  The landscaping should be planned and installed to maintain proper surface drainage conditions.

2. Runoff from driveways, roof gutters, downspouts, planter drains and other improvements should discharge in a non‐erosive manner away from foundations, pavements, and other improvements.   The downspouts may discharge onto splash blocks that direct the flow away from the foundation.

3. Stabilization  of  surface  soils,  particularly  those  disturbed  during  construction,  by vegetation or other means during and following construction is essential to protect the site from erosion damage.  Care should be taken to establish and maintain vegetation.

4. Open areas adjacent to exterior flatwork should be irrigated or otherwise maintained so that constant moisture conditions
are created throughout the year.   Irrigation systems
should  be  controlled  to  the  minimum  levels  that  will  sustain  the  vegetation  without saturating the soil.

5. Bio‐retention  swales  constructed  within  10  feet  or  less  from  the  building  foundation should be lined with a 20‐mil pond liner.

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Geotechnical Observation and Testing

1. It must be recognized that the recommendations contained in this report are based on a limited  number  of  borings  and  rely  on  continuity  of  the  subsurface  conditions encountered.

2. It  is  assumed  that  the  Geotechnical  Engineer  will  be  retained  to  provide  consultation during  the  design  phase,  to  interpret  this  report  during  construction,  and  to  provide construction monitoring in the form of testing and observation.

3. Unless otherwise stated, the terms "compacted" and "recompacted" refer to soils placed in level lifts not exceeding 8 inches in loose thickness and compacted to a minimum of 90 percent of maximum dry density.  The standard tests used to define maximum dry density and field density should be ASTM D 1557‐12 and ASTM D 6938‐17, respectively, or other methods acceptable to the geotechnical engineer and jurisdiction.

4. “Moisture  conditioning”  refers  to  adjusting  the  soil  moisture  to  at  least  3  percentage points above optimum moisture content prior to application of compactive effort.  If the soils are overly moist so that they become unstable, or if the recommended compaction cannot be readily achieved, drying the soil to optimum moisture content or just above may be necessary.   Placement of gravel layers or geotextiles may also be necessary to help  stabilize  unstable  soils.   The  Geotechnical  Engineer  should  be  contacted  for recommendations for mitigating unstable soils.

5.  At a minimum, the following should be provided by the Geotechnical Engineer:

•  Review of final grading and foundation plans,
•  Professional observation during site preparation, grading, and foundation excavation,
•  Oversight of soil compaction testing during grading, •  Oversight of soil special inspection during grading.

6. Special inspection of grading should be provided as per Section 1705.6 and Table 1705.6 of the CBC; the soils special inspector should be under the direction of the Geotechnical Engineer.  In our opinion, the following operations should be subject to continuous soils special inspection:
 Scarification and recompaction,
 Fill placement and compaction,
 Over‐excavation to the recommended depth.

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7. In  our  opinion,  the  following  operations  may  be  subject  to  periodic  soils  special inspection, subject to approval by the Building Official:
 Site preparation,
 Compaction of utility trench backfill,
 Retaining wall backfill,
 Pool excavation,
 Removal of existing development features,
 Compaction of subgrade and aggregate base,
 Observation of foundation and basement excavations,
 Building pad moisture conditioning.

8. It will be necessary to develop a program of quality control prior to beginning grading.  It is  the  responsibility  of  the  owner,  contractor,  or  project  manager  to  determine  any additional  inspection  items  required  by  the  architect/engineer  or  the  governing jurisdiction.

9. The locations and frequencies of compaction tests should be as per the recommendations of  the  Geotechnical  Engineer  at  the  time  of  construction.   The  recommended  test locations and frequencies may be subject to modification by the geotechnical engineer based upon soil and moisture conditions encountered, the size and type of equipment
used  by  the  contractor,  the  general  trend  of  the  compaction  test  results,  and  other factors.

10. A  preconstruction  conference  among  a  representative  of  the  owner,  the  Geotechnical Engineer, soils special inspector, the architect/engineer, and contractors is recommended to  discuss  planned  construction  procedures  and  quality  control  requirements.   Earth

Systems should be notified at least 48 hours prior to beginning grading operations.

7.0  CLOSURE
This report is valid for conditions as they exist at this time for the type of project described herein.

Our intent was to perform the investigation in a manner consistent with the level of care and skill
ordinarily  exercised  by  members  of  the  profession  currently  practicing  in  the  locality  of  this project at this time under similar conditions.  No representation, warranty, or guarantee is either expressed or implied.  This report is intended for the exclusive use by the client as discussed in the Scope of Services section.  Application beyond the stated intent is strictly at the user's risk.

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575 Los Trancos Road   April 9, 2021
Palo Alto, California

304309‐001  17  2104‐004.SER
If changes with respect to the project type or location become necessary, if items not addressed in this report are incorporated into plans, or if any of the assumptions stated in this report are not  correct,  Earth  Systems  should  be  notified  for  modifications  to  this report.   Any  items  not specifically addressed in this report should comply with the CBC and the requirements of the governing jurisdiction.

The  preliminary  recommendations  of  this  report  are  based  upon  the  geotechnical  conditions encountered during the investigation and may be augmented by additional requirements of the architect/engineer,  or  by  additional  recommendations  provided  by  Earth  Systems  based on
conditions exposed at the time of construction.

This document, the data, conclusions, and recommendations contained herein are the property of  Earth  Systems.   This  report  should  be  used  in  its  entirety,  with  no  individual  sections reproduced or used out of context.  Copies may be made only by Earth Systems, the client, and his  authorized  agents  for  use  exclusively  on  the  subject  project.   Any  other  use  is  subject  to federal copyright laws and the written approval of Earth Systems.

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FIGURES

Figure 1  –  Site Location Map
Figure 2    –  Site Plan

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SITE
Base: Google Earth (2021)
Proposed Single Family Residence and ADU
575 Los Trancos Road
Palo Alto, California 304309-001
Site Locaon Map
TN MN

13.2 Figure 1
Earth Systems Pacific
Approximate Scale in Feet
20002000 0 4000
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B-2
B-5
B-3
B-1
CPT-6
HLA-1CPT-7
B-1
CPT-5
304309-001
Base: Google Earth (2021)
Proposed Single Family Residence and ADU
575 Los Trancos Road
Palo Alto, California
Site Plan
Earth Systems Pacific
TN MN

13.2 Figure 2
HLA-4
Approximate Boring Locaon (Harding Lawson Associates, 1989) B-2
HLA-2
HLA-4
HLA-3A
HLA-3
Approximate Boring Locaon (ESP, 2021)
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APPENDIX A

Boring Logs
Harding Lawson Associates
1990

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En|cX.POST rlorts
+J
h
s
3 0
E
tlnLXfv+J.
5+J..{ c00
EC)
f
+J
,sIg 0Llo_OOv
+,
I
E
+J
o-
!o
0 I-tIL
E
Ia
Equ 8" Hollow Stem Au
Laboratory
Tests Elevation 520.0 ft Dat l0 30
l5*
10*
16 5

DARK BROWN SANDY SILT WITH GNAVEL
(ML)
medium atiff, moist, with roots
DARK BROWN SILTY SAND WITH GRAVEL(sM)
medium dense, dry, with roots,
fine-grained aand
becoming brown in color and
decreaaing fine content19.5 percent paasing No, 200 eieve l0 increasing finee content

DARK BROWN SANDY CLAY WITH
GRAVEL (cLlMr)
atiff to very stiff, moist
PI=12 LL=34 t*
lb
tz.E 93
56 r5

RED AND BROWN POORLY GRADED
GRAVEL WrTH SAND (cP)
denee to very dense, dry, giavel in tip of sampler
20 ORj'NGE, RED, AND BROWN CLAYEY
GRAVEL wrTH SAND (CC)
medium dense, moist to wei,
gravela rounded and subangular,
approximately 15 percent fines
LIGHT BROWN SILTY SAND WITH GRAVEL(sM)
medium dense, wet, approximately 30 percent
fineg and 20 percent gravel
MO?TLED ORANGE AND GRAY-BROWN
oLAYEY SAND WITH GRAVEL (sc/sM)
medium dense, wet

BROWN CLAYEY SAND WITH GRAVEL
(sc/cc)
very denae, saturated, rounded and
eubrounded gravela
approxiamtely 15 percent fines
27*
l6

8.0 tt7

26.1 percent paaaing No. 200 sieve
(see Plate ?)
3o/3'* 25
50/6"
30 *Marked blow counts represent
S&H blow counts converted tonpseudo, SPT N-values" by
multiplying field values by

0.6; all other valueg are SPT
N-valuee as defined in ASTM
D1586-84 Test Method; aee
text for more detail.t*Elevations are approximate
and referenced to Mean
Sea Level.
35 PLATEllerdlng Llwron Arrochtor
Engrneer,ng and
Envrronmental Servtces
Log of Boring B-l
Conroe Residence
Palo Alto, California
(sheet I of l)
2 APP ROV E O DATEORAWN JOA NUMEEN
84740-G5 19640,001.04 l/fl4q t /90

REVISEO OATE
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OIETERE I r30tr3
{Jg
at
o
-{E
OaTNfv{J.laJ,.t cooEO
f
+J
Tt.rc urtaoov
{C
.c
+J
o-
fo
0 t
o-
E
Ia
8" Hollow Stem A er
Laboratory
Tests Elevation 520.0 ft l0

17.5 percent passing No. 2O0 sieve DARK BROWN SILTY SAND WITH GRAVEL (sM)
loole, moist, with rootg
BROWN CRAVEL WrTH SAND (cP)
loose to medium dense, dry,
with roote

2.2 percent pasaing No. 200 eieve
(see Plate 8)
g*
72*
DARK BROWN oLAYEY SAND (Sc/sM)
medium dense, moist,
1{ percent gravel, with roote
l0

37.6 percent passing No. 200 gieve
(see Plate 9)
20*
30 I

GRAY AND BROWN POORLY GRADED
GRAVEL wrTH SAND (cP-cC)
denae, moist,
approximtely l0 percent fines and
30 percent sand

ORANGE-BROWN CLAYEY SAND WITH

GRAVEL (SC)
dense, moist,
approximately 15 percent fines and
20 percent rounded gravel
46 46/t"
20 No ground wat€r was encountered
30 35
40 PLATE
Hrrdlng Lewrcn Arrocletrr
Engrneer;ng and
Envrronmental Servrces
Log of Boring B-2
Conroe Residence
Palo Alto, California
(sheet I of l)
3 APPROVE D OATEOAAWN JOB NUMBER
B4740-c5 19640,001.04 w4.44 t/e0

REVISEO OATE
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tcl{-posr tlorrt
+b
t
3 o
t!
o
L+J
f,c+JA8*J...r c00EO
+J
I
I
+J
o,to
0 Boring No. B-3f,
.J
usTC IJ
LO0_oOv
a
(L
E
Ia
Eq 8" Hollow Stem Au
Laboratorv
I EStS
x Elevation 520.0 ft Date l0 30 8
8*
DARK BROWN SrLT (ML)
eoft to medium sriff, moist, with roots

DARK BROWN SILTY SAND WITH
GRAVEL (sM)
loore to medium dense, moist

30.5 percent paesing No.200 sieve
(see Plate 10)
5 15* increasing gravel and eobbles
on cobbles at 7.0 feet
No ground water was encountered
l0
l5
+J
L
t
3 0
E
ot*Jfc+ro!+J
{JI
E
+J

0. fo
0 Boring No B-3At
+J
llsc00tlOv
I
(L
E
ao
Equipme 8" Hollow Stem A r
Laboratorv
Tests
.'l C^ IooN !EOv O Elevation 520.0 ft psls l0/30/89
BRowN SILT (ML)
aoft to medium stiff, moiet, with roots

DARK BROWN SILTY SAND

WITH GRAVEL (SM)
looge to medium denee, moist
increaeing gravel and cobbles at 4 feet
L7 l0' 5
Refugal on cobbles at 5.0 feeb.

No gtound water was encountered
l0
l5
PLATE
Herdlng Lawrqn Anocletor
Engrneer,ng and
Envrronmental Services
Logs of Borings B-3 and B-gA
Conroe Residence
Palo Alto, California 4
JOB NUMAER DATETfl"4b-cs t9640,001.04

APPROVE O
| /90

REVISEO OATE
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olElEnEH'pOSl rlo7l3
+J
s
0 3
0 -{o
0L X JI
+J
ALfrc u
LDILoOv
+J
L Il-{+J O.qg
ttoo
Equ 8" Hollow Stem Augerfv
I-aboratory
Tests
+.
n+J...t c00EO
Elevation 529.0 ft Date--FlloAL
3O/5"*
BLACK srLT (ML)
soft to medium rtiff, moist,
with rootg

BROWN CLAYEY SAND WITH CRAVEL
(sclcc)
dry, with cobbles
5 Refusal on cobbles at 3.0 feet.

No ground water was encountered.
l0
l5
20 25
30 35
Log of Boring B-4
Conroe Residence
Palo Alto, California
(sheet I of l) PLATE
Herdlng Ltwron Arocletrr
Engrneer,ng and
Envrronmental Se.vrces
5 ORAWN JOB NUMEE A OATEAPPROVE D
84740-G5 19640,001.04
wu+ tt /89
R€VISEO OATE
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APPENDIX B

Logs of Test Borings
Earth Systems Pacific
2021

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DEPTH(feet)USCS CLASSSYMBOL
INTERVAL(feet)SAMPLETYPEDRY DENSITY(pcf)MOISTURE(%)BLOWSPER 6 IN.SAMPLE DATASOIL DESCRIPTIONPAGE 1 OF 2JOB NO.: 304309-001DATE: February 23, 2021AUGER TYPE: 8" Hollow StemDRILL RIG: Mobile B-53LOGGED BY: P. PenroseEarth Systems PacificBoring No. 1 LEGEND: 2.5" Mod Cal Sample 2.0" Cal Sample SPT Bulk Sample Groundwater POCKET PEN(t.s.f)
SAMPLENUMBERProposed Residence575 Los Trancos RoadPalo Alto, California

13.5-15.01-4

3.5-5.01-27.5-9.01-3699242122164017
Well graded SAND with GRAVEL; medium dense, dark graybrown, very moist, fine to coarse sand, fine to coarse gravelSW - cobbles, dense

18.5-20.01-596823.5-24.01-650/5"- very dense, less clay, more gravel 113.47.3CLAYEY SAND with GRAVEL; medium dense, gray brown,very moist, fine to coarse sand, fine to coarse gravelSC CLAYEY SAND; loose, brown, wet, mostly fine to mediumsand, trace gravelSC

1.0-2.51-18916110.64.9
[% passing #200 = 18%]
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DEPTH(feet)USCS CLASSSYMBOL
INTERVAL(feet)SAMPLETYPEDRY DENSITY(pcf)MOISTURE(%)BLOWSPER 6 IN.SAMPLE DATASOIL DESCRIPTIONPAGE 2 OF 2JOB NO.: 304309-001DATE: February 23, 2021AUGER TYPE: 8" Hollow StemDRILL RIG: Mobile B-53LOGGED BY: P. PenroseEarth Systems PacificBoring No. 1 LEGEND: 2.5" Mod Cal Sample 2.0" Cal Sample SPT Bulk Sample Groundwater POCKET PEN(t.s.f)
SAMPLENUMBERProposed Residence575 Los Trancos RoadPalo Alto, CaliforniaCLAYEY SAND with GRAVEL (same as above)SC Bottom of boring at 34' bgsNo Groundwater encountered1-850/5"33.5-34.0- blue gray1-750/4"28.5-29.0 ITEM 13
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DEPTH(feet)USCS CLASSSYMBOL
INTERVAL(feet)SAMPLETYPEDRY DENSITY(pcf)MOISTURE(%)BLOWSPER 6 IN.SAMPLE DATASOIL DESCRIPTIONPAGE 1 OF 2JOB NO.: 304309-001DATE: February 23, 2021AUGER TYPE: 8" Hollow StemDRILL RIG: Mobile B-53LOGGED BY: P. PenroseEarth Systems PacificBoring No. 2 LEGEND: 2.5" Mod Cal Sample 2.0" Cal Sample SPT Bulk Sample Groundwater POCKET PEN(t.s.f)
SAMPLENUMBERProposed Residence575 Los Trancos RoadPalo Alto, California

13.5-15.02-4

3.5-5.02-28.5-10.02-3566691251041
CLAYEY SAND with GRAVEL; loose, gray brown, moist, fineto coarse sand, fine to coarse gravelSC - medium dense

18.5-20.02-510152023.5-25.02-6251216
- very dense, gray, very moist
102.111.1
115.718.4Well graded SAND with CLAY and GRAVEL; medium dense,gray brown, wet, fine to coarse sand, fine to coarse gravelSW-SC

1.0-2.52-1556103.412.9
CLAYEY SAND with GRAVEL; medium dense, gray brown,wet, fine to coarse sand, fine gravelSC [% passing #200 = 21%]
[% passing #200 = 9%][% passing #200 = 31%]
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DEPTH(feet)USCS CLASSSYMBOL
INTERVAL(feet)SAMPLETYPEDRY DENSITY(pcf)MOISTURE(%)BLOWSPER 6 IN.SAMPLE DATASOIL DESCRIPTIONPAGE 2 OF 2JOB NO.: 304309-001DATE: February 23, 2021AUGER TYPE: 8" Hollow StemDRILL RIG: Mobile B-53LOGGED BY: P. PenroseEarth Systems PacificBoring No. 2 LEGEND: 2.5" Mod Cal Sample 2.0" Cal Sample SPT Bulk Sample Groundwater POCKET PEN(t.s.f)
SAMPLENUMBERProposed Residence575 Los Trancos RoadPalo Alto, CaliforniaCLAYEY SAND with GRAVEL (same as above)SC Bottom of boring at 34' bgsGroundwater encountered at 17' bgs2-850/6"33.5-34.02-79113028.5-29.0Well graded SAND with CLAY and GRAVEL; dense, graybrown, wet, fine to coarse sand, fine to coarse gravelSW-SC ITEM 13
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APPENDIX C

Summary of Laboratory Test Results
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575 Los Trancos Road 304309‐001
BULK DENSITY TEST RESULTS ASTM D 2937‐17 (modified for ring liners) March 4, 2021

BORING DEPTH MOISTURE WET DRY
NO. feet CONTENT, % DENSITY, pcf DENSITY, pcf
1‐1 2.0 ‐ 2.5 4.9 116.0 110.6
1‐2 4.5 ‐ 5.0 7.3 121.7 113.4
2‐1 2.0 ‐ 2.5 12.9 116.7 103.4
2‐2 4.5 ‐ 5.0 11.1 113.4 102.1
2‐4 14.5 ‐ 15.0 18.4 137.0 115.7
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575 Los Trancos Road 304309‐001
PARTICLE SIZE ANALYSIS ASTM D 422‐63/07; D 1140‐17
Boring #1 @ 18.5 ‐ 20.0' March 4, 2021
Sieve size % Retained % Passing
3" (75‐mm) 0 100
2" (50‐mm) 0 100

1.5" (37.5‐mm) 0 100
1" (25‐mm) 0 100
3/4" (19‐mm) 0 100
1/2" (12.5‐mm) 0 100
3/8" (9.5‐mm) 0 100
#4 (4.75‐mm) 0 100
#8 (2.36‐mm) 0 100
#16 (1.18‐mm) 0 100
#30 (600‐µm) 0 100
#50 (300‐µm) 0 100
#100 (150‐µm) 0 100
#200 (75‐µm) 82 18
3 2 1.5 1 3/4 1/2 3/8 4 8 16 30 50 100 200
0 10
20 30
40 50
60 70
80 90
100

0.010.1110100

PERCENT PASSING
GRAIN SIZE, mm
U. S. STANDARD SIEVE NUMBERSU. S. STANDARD SIEVE OPENING IN INCHES ITEM 13
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575 Los Trancos Road 304309‐001
PARTICLE SIZE ANALYSIS ASTM D 422‐63/07; D 1140‐14
Boring #2 @ 8.5 ‐ 10.0' March 4, 2021
Dark Brown Well Graded Sand with Clay and Gravel (SW‐SC) Sieve size % Retained % Passing
3" (75‐mm) 0 100
2" (50‐mm) 0 100

1.5" (37.5‐mm) 0 100
1" (25‐mm) 0 100
3/4" (19‐mm) 0 100
1/2" (12.5‐mm) 0 100
3/8" (9.5‐mm) 0 100
#4 (4.75‐mm) 0 100
#8 (2.36‐mm) 0 100
#16 (1.18‐mm) 0 100
#30 (600‐µm) 0 100
#50 (300‐µm) 0 100
#100 (150‐µm) 0 100
#200 (75‐µm) 79 21
3 2 1.5 1 3/4 1/2 3/8 4 8 16 30 50 100 200
0 10
20 30
40 50
60 70
80 90
100

0.010.1110100

PERCENT PASSING
GRAIN SIZE, mm
U. S. STANDARD SIEVE NUMBERSU. S. STANDARD SIEVE OPENING IN INCHES ITEM 13
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575 Los Trancos Road 304309‐001
PARTICLE SIZE ANALYSIS ASTM D 422‐63/07; D 1140‐17
Boring #2 @ 18.5 ‐ 20.0' March 4, 2021
Dark Yellowish Brown Clayey Sand with Gravel (SC)
Sieve size % Retained % Passing
3" (75‐mm) 0 100
2" (50‐mm) 0 100

1.5" (37.5‐mm) 0 100
1" (25‐mm) 0 100
3/4" (19‐mm) 0 100
1/2" (12.5‐mm) 0 100
3/8" (9.5‐mm) 0 100
#4 (4.75‐mm) 0 100
#8 (2.36‐mm) 0 100
#16 (1.18‐mm) 0 100
#30 (600‐µm) 0 100
#50 (300‐µm) 0 100
#100 (150‐µm) 0 100
#200 (75‐µm) 91 9
3 2 1.5 1 3/4 1/2 3/8 4 8 16 30 50 100 200
0 10
20 30
40 50
60 70
80 90
100

0.010.1110100

PERCENT PASSING
GRAIN SIZE, mm
U. S. STANDARD SIEVE NUMBERSU. S. STANDARD SIEVE OPENING IN INCHES ITEM 13
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575 Los Trancos Road 304309‐001
PARTICLE SIZE ANALYSIS ASTM D 422‐63/07; D 1140‐17
Boring #2 @ 23.5 ‐ 25.0' March 4, 2021
Dark Yellowish Brown Clayey Sand with Gravel (SC)
Sieve size % Retained % Passing
3" (75‐mm) 0 100
2" (50‐mm) 0 100

1.5" (37.5‐mm) 0 100
1" (25‐mm) 0 100
3/4" (19‐mm) 0 100
1/2" (12.5‐mm) 0 100
3/8" (9.5‐mm) 0 100
#4 (4.75‐mm) 0 100
#8 (2.36‐mm) 0 100
#16 (1.18‐mm) 0 100
#30 (600‐µm) 0 100
#50 (300‐µm) 0 100
#100 (150‐µm) 0 100
#200 (75‐µm) 69 31
3 2 1.5 1 3/4 1/2 3/8 4 8 16 30 50 100 200
0 10
20 30
40 50
60 70
80 90
100

0.010.1110100

PERCENT PASSING
GRAIN SIZE, mm
U. S. STANDARD SIEVE NUMBERSU. S. STANDARD SIEVE OPENING IN INCHES ITEM 13
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APPENDIX D

Liquefaction Analysis
Dry Sand Settlement
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S P T B A S ED L IQ UEFA C TIO N A NA L YS IS R EP O R T :: Input parameters and analysis properties ::

Analysis method:

Fines correction method:

Sampling method:

Borehole diameter:

Rod length:

Hammer energy ratio:

Boulanger & Idriss, 2014
Boulanger & Idriss, 2014
Standard Sampler
200mm

3.30 ft

1.00 G.W.T. (in-situ):

G.W.T. (earthq.):

Earthquake magnitude Mw:

Peak ground acceleration:

Eq. external load:

Project title : 575 Los Trancos Road Residence
Location : Palo Alto, California
SPT Name: B-1

18.00 ft

8.00 ft

7.80 1.16 g

0.00 tsf
Raw SPT Data
SPT Count (blows/ft)
50403020100
Depth (ft)
32 30
28 26
24 22
20 18
16 14
12 10
8 6
4 2
Raw SPT Data
Insitu
CSR - CRR Plot

CSR - CRR

10.80.60.40.20 Depth (ft)
32 30
28 26
24 22
20 18
16 14
12 10
8 6
4 2
CSR - CRR Plot
During earthq.

FS Plot
Factor of Safety

21.510.50
Depth (ft)
32 30
28 26
24 22
20 18
16 14
12 10
8 6
4 2
FS Plot
During earthq.

LPI
Liquefaction potential
50 Depth (ft)
32 30
28 26
24 22
20 18
16 14
12 10
8 6
4 2
LPI
During earthq.

CRR 7.50 clean sand curve
Corrected Blow Count N1(60),cs
50454035302520151050
Cyclic Stress Ratio*

0.8 0.7

0.6 0.5

0.4 0.3

0.2 0.1

0.0 CRR 7.50 clean sand curve
Liquefaction
No Liquefaction
F.S. color scheme
Almost certain it will liquefy
Very likely to liquefy
Liquefaction and no liq. are equally likely
Unlike to liquefy
Almost certain it will not liquefy
LPI color scheme
Very high risk
High risk
Low risk
Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 1LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

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This software is registered to: Earth Systems Pacific
Raw SPT Data
SPT Count (blows/ft)
50403020100
Depth (ft)
33 32
31 30
29 28
27 26
25 24
23 22
21 20
19 18
17 16
15 14
13 12
11 10
9 8
7 6
5 4
3 2
1 Raw SPT Data
Insitu
CSR - CRR Plot

CSR - CRR

10.80.60.40.20 Depth (ft)
33 32
31 30
29 28
27 26
25 24
23 22
21 20
19 18
17 16
15 14
13 12
11 10
9 8
7 6
5 4
3 2
1 CSR - CRR Plot
During earthq.

FS Plot
Factor of Safety

21.510.50
Depth (ft)
33 32
31 30
29 28
27 26
25 24
23 22
21 20
19 18
17 16
15 14
13 12
11 10
9 8
7 6
5 4
3 2
1 FS Plot
During earthq.

Vertical Liq. Settlements
Cuml. Settlement (in)

10.50 Depth (ft)
33 32
31 30
29 28
27 26
25 24
23 22
21 20
19 18
17 16
15 14
13 12
11 10
9 8
7 6
5 4
3 2
1 Vertical Liq. Settlements
During earthq.

Lateral Liq. Displacements
Cuml. Displacement (ft)

0.50 Depth (ft)
33 32
31 30
29 28
27 26
25 24
23 22
21 20
19 18
17 16
15 14
13 12
11 10
9 8
7 6
5 4
3 2
1 Lateral Liq. Displacements
During earthq.
:: Overall Liquefaction Assessment Analysis Plots ::

Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 2LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road Residential
Project Final IS-MND with Appendices

Item 13:

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This software is registered to: Earth Systems Pacific
Test
Depth
(ft)
:: Field input data ::

SPT Field
Value
(blows)
Fines
Content
(%)
Unit
Weight
(pcf)
Infl.

Thickness
(ft)
Can
Liquefy

0.50 16 5.00 116.00 1.00 Yes

1.50 16 5.00 116.00 1.00 Yes

2.50 16 5.00 116.00 1.00 Yes

3.50 12 5.00 122.00 1.00 Yes

4.50 12 5.00 122.00 1.00 Yes

5.50 12 18.00 122.00 1.00 Yes

6.50 12 18.00 122.00 1.00 Yes

7.50 43 18.00 120.00 1.00 Yes

8.50 43 18.00 120.00 1.00 Yes

9.50 43 18.00 120.00 1.00 Yes

10.50 43 18.00 120.00 1.00 Yes

11.50 43 18.00 120.00 1.00 Yes

12.50 43 18.00 120.00 1.00 Yes

13.50 33 18.00 120.00 1.00 Yes

14.50 33 18.00 120.00 1.00 Yes

15.50 33 18.00 120.00 1.00 Yes

16.50 33 18.00 120.00 1.00 Yes

17.50 33 18.00 120.00 1.00 Yes

18.50 14 18.00 120.00 1.00 Yes

19.50 14 18.00 120.00 1.00 Yes

20.50 14 18.00 120.00 1.00 Yes

21.50 14 18.00 120.00 1.00 Yes

22.50 14 18.00 120.00 1.00 Yes

23.50 100 18.00 120.00 1.00 Yes

24.50 100 18.00 120.00 1.00 Yes

25.50 100 18.00 120.00 1.00 Yes

26.50 100 18.00 120.00 1.00 Yes

27.50 100 18.00 120.00 1.00 Yes

28.50 100 18.00 120.00 1.00 Yes

29.50 100 18.00 120.00 1.00 Yes

30.50 100 18.00 120.00 1.00 Yes

31.50 100 18.00 120.00 1.00 Yes

32.50 100 18.00 120.00 1.00 Yes

33.50 100 18.00 120.00 1.00 Yes
Abbreviations
Depth:

SPT Field Value:

Fines Content:

Unit Weight:

Infl. Thickness:

Can Liquefy:

Depth at which test was performed (ft)
Number of blows per foot
Fines content at test depth (%)
Unit weight at test depth (pcf)
Thickness of the soil layer to be considered in settlements analysis (ft) User defined switch for excluding/including test depth from the analysis procedure :: Cyclic Resistance Ratio (CRR) calculation data ::

CRR7.5Depth
(ft)
SPT
Field
Value
CN CE CB CR CS (N1)60 (N1)60csFC
(%)
σv
(tsf)
uo
(tsf)
σ'vo
(tsf)
Unit
Weight
(pcf)
Δ(Ν1)60m

0.50 16 1.70 1.00 1.15 0.75 1.00 23 23 4.0005.00116.00 0.03 0.00 0.03 0.41 0.00

1.50 16 1.70 1.00 1.15 0.75 1.00 23 23 4.0005.00116.00 0.09 0.00 0.09 0.41 0.00

2.50 16 1.70 1.00 1.15 0.75 1.00 23 23 4.0005.00116.00 0.15 0.00 0.15 0.41 0.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 3LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
231
Packet Page 661 of 792

This software is registered to: Earth Systems Pacific
:: Cyclic Resistance Ratio (CRR) calculation data ::

CRR7.5Depth
(ft)
SPT
Field
Value
CN CE CB CR CS (N1)60 (N1)60csFC
(%)
σv
(tsf)
uo
(tsf)
σ'vo
(tsf)
Unit
Weight
(pcf)
Δ(Ν1)60m

3.50 12 1.70 1.00 1.15 0.75 1.00 18 18 4.0005.00122.00 0.21 0.00 0.21 0.46 0.00

4.50 12 1.70 1.00 1.15 0.75 1.00 18 18 4.0005.00122.00 0.27 0.00 0.27 0.46 0.00

5.50 12 1.62 1.00 1.15 0.75 1.00 17 21 4.00018.00122.00 0.33 0.00 0.33 0.41 4.09

6.50 12 1.53 1.00 1.15 0.75 1.00 16 20 4.00018.00122.00 0.39 0.00 0.39 0.42 4.09

7.50 43 1.25 1.00 1.15 0.80 1.00 50 54 4.00018.00120.00 0.45 0.00 0.45 0.26 4.09

8.50 43 1.21 1.00 1.15 0.80 1.00 48 52 4.00018.00120.00 0.51 0.00 0.51 0.26 4.09

9.50 43 1.18 1.00 1.15 0.80 1.00 47 51 4.00018.00120.00 0.57 0.00 0.57 0.26 4.09

10.50 43 1.15 1.00 1.15 0.85 1.00 48 52 4.00018.00120.00 0.63 0.00 0.63 0.26 4.09

11.50 43 1.12 1.00 1.15 0.85 1.00 47 51 4.00018.00120.00 0.69 0.00 0.69 0.26 4.09

12.50 43 1.10 1.00 1.15 0.85 1.00 46 50 4.00018.00120.00 0.75 0.00 0.75 0.26 4.09

13.50 33 1.08 1.00 1.15 0.85 1.00 35 39 4.00018.00120.00 0.81 0.00 0.81 0.30 4.09

14.50 33 1.06 1.00 1.15 0.85 1.00 34 38 4.00018.00120.00 0.87 0.00 0.87 0.31 4.09

15.50 33 1.04 1.00 1.15 0.85 1.00 34 38 4.00018.00120.00 0.93 0.00 0.93 0.31 4.09

16.50 33 1.02 1.00 1.15 0.95 1.00 37 41 4.00018.00120.00 0.99 0.00 0.99 0.29 4.09

17.50 33 1.00 1.00 1.15 0.95 1.00 36 40 4.00018.00120.00 1.05 0.00 1.05 0.30 4.09

18.50 14 0.99 1.00 1.15 0.95 1.00 15 19 0.19418.00120.00 1.11 0.02 1.09 0.45 4.09

19.50 14 0.97 1.00 1.15 0.95 1.00 15 19 0.19418.00120.00 1.17 0.05 1.12 0.45 4.09

20.50 14 0.96 1.00 1.15 0.95 1.00 15 19 0.19418.00120.00 1.23 0.08 1.15 0.45 4.09

21.50 14 0.95 1.00 1.15 0.95 1.00 15 19 0.19418.00120.00 1.29 0.11 1.18 0.45 4.09

22.50 14 0.94 1.00 1.15 0.95 1.00 14 18 0.18418.00120.00 1.35 0.14 1.21 0.46 4.09

23.50 100 0.96 1.00 1.15 0.95 1.00 105 109 4.00018.00120.00 1.41 0.17 1.24 0.26 4.09

24.50 100 0.95 1.00 1.15 0.95 1.00 104 108 4.00018.00120.00 1.47 0.20 1.27 0.26 4.09

25.50 100 0.95 1.00 1.15 0.95 1.00 104 108 4.00018.00120.00 1.53 0.23 1.30 0.26 4.09

26.50 100 0.94 1.00 1.15 0.95 1.00 103 107 4.00018.00120.00 1.59 0.27 1.32 0.26 4.09

27.50 100 0.94 1.00 1.15 0.95 1.00 102 106 4.00018.00120.00 1.65 0.30 1.35 0.26 4.09

28.50 100 0.93 1.00 1.15 0.95 1.00 102 106 4.00018.00120.00 1.71 0.33 1.38 0.26 4.09

29.50 100 0.93 1.00 1.15 0.95 1.00 101 105 4.00018.00120.00 1.77 0.36 1.41 0.26 4.09

30.50 100 0.92 1.00 1.15 1.00 1.00 106 110 4.00018.00120.00 1.83 0.39 1.44 0.26 4.09

31.50 100 0.92 1.00 1.15 1.00 1.00 106 110 4.00018.00120.00 1.89 0.42 1.47 0.26 4.09

32.50 100 0.91 1.00 1.15 1.00 1.00 105 109 4.00018.00120.00 1.95 0.45 1.50 0.26 4.09

33.50 100 0.91 1.00 1.15 1.00 1.00 104 108 4.00018.00120.00 2.01 0.48 1.53 0.26 4.09 σv:
uo:
σ'vo:
m:

CN:

CE:

CB:

CR:

CS:

N1(60):

Δ(Ν1)60
N1 (60) cs:

CRR7.5:

Total stress during SPT test (tsf)
Water pore pressure during SPT test (tsf)
Effective overburden pressure during SPT test (tsf)
Stress exponent normalization factor
Overburden corretion factor
Energy correction factor
Borehole diameter correction factor
Rod length correction factor
Liner correction factor
Corrected N SPT to a 60% energy ratio
Equivalent clean sand adjustment
Corected N1(60) value for fines content
Cyclic resistance ratio for M=7.5
Abbreviations
σv , e q
(tsf)
rd CSR MSF CSRe q,M =7.5Ksi gma CSR*
:: Cyclic Stress Ratio calculation (CSR fully adjusted and normalized) ::

Depth
(ft)
Unit
Weight
(pcf)
uo, e q
(tsf)
σ'v o,eq
(tsf)
FSMSFma x (N1)60csα

0.50 116.00 0.03 0.00 0.03 1.01 0.758 0.94 0.806 1.10 0.733 2.0001.62 231.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 4LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
232
Packet Page 662 of 792

This software is registered to: Earth Systems Pacific
σv , e q
(tsf)
rd CSR MSF CSRe q,M =7.5Ksi gma CSR*
:: Cyclic Stress Ratio calculation (CSR fully adjusted and normalized) ::

Depth
(ft)
Unit
Weight
(pcf)
uo, e q
(tsf)
σ'v o,eq
(tsf)
FSMSFma x (N1)60csα

1.50 116.00 0.09 0.00 0.09 1.00 0.757 0.94 0.805 1.10 0.731 2.0001.62 231.00

2.50 116.00 0.15 0.00 0.15 1.00 0.755 0.94 0.803 1.10 0.730 2.0001.62 231.00

3.50 122.00 0.21 0.00 0.21 1.00 0.754 0.96 0.785 1.10 0.714 2.0001.42 181.00

4.50 122.00 0.27 0.00 0.27 1.00 0.752 0.96 0.784 1.10 0.712 2.0001.42 181.00

5.50 122.00 0.33 0.00 0.33 1.00 0.751 0.95 0.791 1.10 0.719 2.0001.53 211.00

6.50 122.00 0.39 0.00 0.39 0.99 0.749 0.95 0.787 1.10 0.715 2.0001.49 201.00

7.50 120.00 0.45 0.00 0.45 0.99 0.748 0.89 0.845 1.10 0.768 2.0002.20 541.00

8.50 120.00 0.51 0.02 0.49 0.99 0.770 0.89 0.870 1.10 0.791 2.0002.20 521.00

9.50 120.00 0.57 0.05 0.52 0.99 0.811 0.89 0.916 1.10 0.833 2.0002.20 511.00

10.50 120.00 0.63 0.08 0.55 0.98 0.848 0.89 0.958 1.10 0.871 2.0002.20 521.00

11.50 120.00 0.69 0.11 0.58 0.98 0.880 0.89 0.995 1.10 0.904 2.0002.20 511.00

12.50 120.00 0.75 0.14 0.61 0.98 0.909 0.89 1.027 1.10 0.934 2.0002.20 501.00

13.50 120.00 0.81 0.17 0.64 0.98 0.935 0.89 1.057 1.10 0.961 2.0002.20 391.00

14.50 120.00 0.87 0.20 0.67 0.97 0.959 0.89 1.083 1.10 0.985 2.0002.20 381.00

15.50 120.00 0.93 0.23 0.70 0.97 0.980 0.89 1.107 1.10 1.006 2.0002.20 381.00

16.50 120.00 0.99 0.27 0.72 0.97 0.999 0.89 1.128 1.10 1.026 2.0002.20 411.00

17.50 120.00 1.05 0.30 0.75 0.97 1.016 0.89 1.148 1.10 1.043 2.0002.20 401.00

18.50 120.00 1.11 0.33 0.78 0.96 1.031 0.96 1.078 1.04 1.038 0.1871.45 191.00

19.50 120.00 1.17 0.36 0.81 0.96 1.045 0.96 1.093 1.03 1.056 0.1841.45 191.00

20.50 120.00 1.23 0.39 0.84 0.96 1.058 0.96 1.106 1.03 1.074 0.1811.45 191.00

21.50 120.00 1.29 0.42 0.87 0.95 1.069 0.96 1.118 1.03 1.090 0.1781.45 191.00

22.50 120.00 1.35 0.45 0.90 0.95 1.079 0.96 1.124 1.02 1.102 0.1671.42 181.00

23.50 120.00 1.41 0.48 0.93 0.95 1.089 0.89 1.230 1.04 1.183 2.0002.20 1091.00

24.50 120.00 1.47 0.51 0.95 0.95 1.097 0.89 1.240 1.03 1.203 2.0002.20 1081.00

25.50 120.00 1.53 0.55 0.98 0.94 1.105 0.89 1.248 1.02 1.222 2.0002.20 1081.00

26.50 120.00 1.59 0.58 1.01 0.94 1.111 0.89 1.256 1.01 1.239 2.0002.20 1071.00

27.50 120.00 1.65 0.61 1.04 0.94 1.118 0.89 1.263 1.00 1.256 2.0002.20 1061.00

28.50 120.00 1.71 0.64 1.07 0.93 1.123 0.89 1.269 1.00 1.273 2.0002.20 1061.00

29.50 120.00 1.77 0.67 1.10 0.93 1.128 0.89 1.274 0.99 1.288 2.0002.20 1051.00

30.50 120.00 1.83 0.70 1.13 0.93 1.132 0.89 1.279 0.98 1.303 2.0002.20 1101.00

31.50 120.00 1.89 0.73 1.16 0.92 1.136 0.89 1.283 0.97 1.317 2.0002.20 1101.00

32.50 120.00 1.95 0.76 1.18 0.92 1.139 0.89 1.287 0.97 1.331 2.0002.20 1091.00

33.50 120.00 2.01 0.80 1.21 0.91 1.141 0.89 1.290 0.96 1.344 2.0002.20 1081.00 σv, eq:
uo, eq:
σ'vo, eq:
rd:
α:

CSR :

MSF :

CSReq, M=7. 5:

Ksigma:

CSR*:

FS:

Total overburden pressure at test point, during earthquake (tsf) Water pressure at test point, during earthquake (tsf)
Effective overburden pressure, during earthquake (tsf)
Nonlinear shear mass factor
Improvement factor due to stone columns
Cyclic Stress Ratio
Magnitude Scaling Factor
CSR adjusted for M=7.5
Effective overburden stress factor
CSR fully adjusted (user FS applied)***
Calculated factor of safety against soil liquefaction
Abbreviations

1.00* ** User FS:
:: Liquefaction potential according to Iwasaki ::

Depth
(ft)
FS F Thickness
(ft)
wz IL
Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 5LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

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This software is registered to: Earth Systems Pacific
:: Liquefaction potential according to Iwasaki ::

Depth
(ft)
FS F Thickness
(ft)
wz IL

0.50 2.000 0.00 9.92 0.001.00

1.50 2.000 0.00 9.77 0.001.00

2.50 2.000 0.00 9.62 0.001.00

3.50 2.000 0.00 9.47 0.001.00

4.50 2.000 0.00 9.31 0.001.00

5.50 2.000 0.00 9.16 0.001.00

6.50 2.000 0.00 9.01 0.001.00

7.50 2.000 0.00 8.86 0.001.00

8.50 2.000 0.00 8.70 0.001.00

9.50 2.000 0.00 8.55 0.001.00

10.50 2.000 0.00 8.40 0.001.00

11.50 2.000 0.00 8.25 0.001.00

12.50 2.000 0.00 8.10 0.001.00

13.50 2.000 0.00 7.94 0.001.00

14.50 2.000 0.00 7.79 0.001.00

15.50 2.000 0.00 7.64 0.001.00

16.50 2.000 0.00 7.49 0.001.00

17.50 2.000 0.00 7.33 0.001.00

18.50 0.187 0.81 7.18 1.781.00

19.50 0.184 0.82 7.03 1.751.00

20.50 0.181 0.82 6.88 1.721.00

21.50 0.178 0.82 6.72 1.681.00

22.50 0.167 0.83 6.57 1.671.00

23.50 2.000 0.00 6.42 0.001.00

24.50 2.000 0.00 6.27 0.001.00

25.50 2.000 0.00 6.11 0.001.00

26.50 2.000 0.00 5.96 0.001.00

27.50 2.000 0.00 5.81 0.001.00

28.50 2.000 0.00 5.66 0.001.00

29.50 2.000 0.00 5.50 0.001.00

30.50 2.000 0.00 5.35 0.001.00

31.50 2.000 0.00 5.20 0.001.00

32.50 2.000 0.00 5.05 0.001.00

33.50 2.000 0.00 4.89 0.001.00

8.60 IL = 0.00 - No liquefaction
IL between 0.00 and 5 - Liquefaction not probable
IL between 5 and 15 - Liquefaction probable
IL > 15 - Liquefaction certain
Overall potential I L :
:: Vertical settlements estimation for dry sands ::

Depth
(ft)
(N1)60 τav p Gma x
(tsf)
α b γ ε15 Nc εNc
(% )
ΔS
(in)
Δh
(ft)

0.50 23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

1.50 23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

2.50 23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

3.50 18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 6LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
234
Packet Page 664 of 792

This software is registered to: Earth Systems Pacific
:: Vertical settlements estimation for dry sands ::

Depth
(ft)
(N1)60 τav p Gma x
(tsf)
α b γ ε15 Nc εNc
(% )
ΔS
(in)
Δh
(ft)

4.50 18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

5.50 17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

6.50 16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

7.50 50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00 Abbreviations
τav:
p:

Gmax:
α, b:
γ:
ε15:

Nc:
εNc:

Δh:

ΔS:

Average cyclic shear stress
Average stress
Maximum shear modulus (tsf)
Shear strain formula variables
Average shear strain
Volumetric strain after 15 cycles
Number of cycles
Volumetric strain for number of cycles Nc (%)
Thickness of soil layer (in)
Settlement of soil layer (in)

0.000Cumulative settlemetns:
:: Vertical & Lateral displ.acements estimation for saturated sands ::

Depth
(ft)
γl im
(% )
ev
(% )
dz
(ft)
Sv-1D
(in)
(N1)60cs Fα γmax
(% )
FSliq LDI
(ft)

8.50 52 0.01 -1.75 2.000 0.00 0.00 1.00 0.000 0.00

9.50 51 0.02 -1.67 2.000 0.00 0.00 1.00 0.000 0.00

10.50 52 0.01 -1.75 2.000 0.00 0.00 1.00 0.000 0.00

11.50 51 0.02 -1.67 2.000 0.00 0.00 1.00 0.000 0.00

12.50 50 0.04 -1.59 2.000 0.00 0.00 1.00 0.000 0.00

13.50 39 1.07 -0.73 2.000 0.00 0.00 1.00 0.000 0.00

14.50 38 1.30 -0.65 2.000 0.00 0.00 1.00 0.000 0.00

15.50 38 1.30 -0.65 2.000 0.00 0.00 1.00 0.000 0.00

16.50 41 0.70 -0.88 2.000 0.00 0.00 1.00 0.000 0.00

17.50 40 0.87 -0.80 2.000 0.00 0.00 1.00 0.000 0.00

18.50 19 17.78 0.57 0.187 17.78 2.40 1.00 0.288 0.18

19.50 19 17.78 0.57 0.184 17.78 2.40 1.00 0.288 0.18

20.50 19 17.78 0.57 0.181 17.78 2.40 1.00 0.288 0.18

21.50 19 17.78 0.57 0.178 17.78 2.40 1.00 0.288 0.18

22.50 18 19.85 0.62 0.167 19.85 2.51 1.00 0.301 0.20

23.50 109 0.00 -6.93 2.000 0.00 0.00 1.00 0.000 0.00

24.50 108 0.00 -6.84 2.000 0.00 0.00 1.00 0.000 0.00

25.50 108 0.00 -6.84 2.000 0.00 0.00 1.00 0.000 0.00

26.50 107 0.00 -6.74 2.000 0.00 0.00 1.00 0.000 0.00

27.50 106 0.00 -6.64 2.000 0.00 0.00 1.00 0.000 0.00

28.50 106 0.00 -6.64 2.000 0.00 0.00 1.00 0.000 0.00

29.50 105 0.00 -6.55 2.000 0.00 0.00 1.00 0.000 0.00

30.50 110 0.00 -7.03 2.000 0.00 0.00 1.00 0.000 0.00

31.50 110 0.00 -7.03 2.000 0.00 0.00 1.00 0.000 0.00

32.50 109 0.00 -6.93 2.000 0.00 0.00 1.00 0.000 0.00

33.50 108 0.00 -6.84 2.000 0.00 0.00 1.00 0.000 0.00
Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 7LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
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Packet Page 665 of 792

This software is registered to: Earth Systems Pacific
:: Vertical & Lateral displ.acements estimation for saturated sands ::

Depth
(ft)
γl im
(% )
ev
(% )
dz
(ft)
Sv-1D
(in)
(N1)60cs Fα γmax
(% )
FSliq LDI
(ft)
Abbreviations

1.454Cumulative settlements:
γlim:

Fα/N:
γm ax:
ev::

Sv-1D:

LDI:

Limiting shear strain (%)
Maximun shear strain factor
Maximum shear strain (%)
Post liquefaction volumetric strain (%)
Estimated vertical settlement (in)
Estimated lateral displacement (ft)

0.91 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 8LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
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Packet Page 666 of 792

S P T B A S ED L IQ UEFA C TIO N A NA L YS IS R EP O R T :: Input parameters and analysis properties ::

Analysis method:

Fines correction method:

Sampling method:

Borehole diameter:

Rod length:

Hammer energy ratio:

Boulanger & Idriss, 2014
Boulanger & Idriss, 2014
Standard Sampler
200mm

3.30 ft

1.00 G.W.T. (in-situ):

G.W.T. (earthq.):

Earthquake magnitude Mw:

Peak ground acceleration:

Eq. external load:

Project title : 575 Los Trancos Road Residence
Location : Palo Alto, California
SPT Name: B-2

17.00 ft

8.00 ft

7.80 1.16 g

0.00 tsf
Raw SPT Data
SPT Count (blows/ft)
50403020100
Depth (ft)
32 30
28 26
24 22
20 18
16 14
12 10
8 6
4 2
Raw SPT Data
Insitu
CSR - CRR Plot

CSR - CRR

10.80.60.40.20 Depth (ft)
32 30
28 26
24 22
20 18
16 14
12 10
8 6
4 2
CSR - CRR Plot
During earthq.

FS Plot
Factor of Safety

21.510.50
Depth (ft)
32 30
28 26
24 22
20 18
16 14
12 10
8 6
4 2
FS Plot
During earthq.

LPI
Liquefaction potential
6420
Depth (ft)
32 30
28 26
24 22
20 18
16 14
12 10
8 6
4 2
LPI
During earthq.

CRR 7.50 clean sand curve
Corrected Blow Count N1(60),cs
50454035302520151050
Cyclic Stress Ratio*

0.8 0.7

0.6 0.5

0.4 0.3

0.2 0.1

0.0 CRR 7.50 clean sand curve
Liquefaction
No Liquefaction
F.S. color scheme
Almost certain it will liquefy
Very likely to liquefy
Liquefaction and no liq. are equally likely
Unlike to liquefy
Almost certain it will not liquefy
LPI color scheme
Very high risk
High risk
Low risk
Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 9LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
237
Packet Page 667 of 792

This software is registered to: Earth Systems Pacific
Raw SPT Data
SPT Count (blows/ft)
50403020100
Depth (ft)
33 32
31 30
29 28
27 26
25 24
23 22
21 20
19 18
17 16
15 14
13 12
11 10
9 8
7 6
5 4
3 2
1 Raw SPT Data
Insitu
CSR - CRR Plot

CSR - CRR

10.80.60.40.20 Depth (ft)
33 32
31 30
29 28
27 26
25 24
23 22
21 20
19 18
17 16
15 14
13 12
11 10
9 8
7 6
5 4
3 2
1 CSR - CRR Plot
During earthq.

FS Plot
Factor of Safety

21.510.50
Depth (ft)
33 32
31 30
29 28
27 26
25 24
23 22
21 20
19 18
17 16
15 14
13 12
11 10
9 8
7 6
5 4
3 2
1 FS Plot
During earthq.

Vertical Liq. Settlements
Cuml. Settlement (in)

0.60.40.20 Depth (ft)
33 32
31 30
29 28
27 26
25 24
23 22
21 20
19 18
17 16
15 14
13 12
11 10
9 8
7 6
5 4
3 2
1 Vertical Liq. Settlements
During earthq.

Lateral Liq. Displacements
Cuml. Displacement (ft)
0 Depth (ft)
33 32
31 30
29 28
27 26
25 24
23 22
21 20
19 18
17 16
15 14
13 12
11 10
9 8
7 6
5 4
3 2
1 Lateral Liq. Displacements
During earthq.
:: Overall Liquefaction Assessment Analysis Plots ::

Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 10LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road Residential
Project Final IS-MND with Appendices

Item 13:

Page
238
Packet Page 668 of 792

This software is registered to: Earth Systems Pacific
Test
Depth
(ft)
:: Field input data ::

SPT Field
Value
(blows)
Fines
Content
(%)
Unit
Weight
(pcf)
Infl.

Thickness
(ft)
Can
Liquefy

0.50 7 21.00 117.00 1.00 Yes

1.50 7 21.00 117.00 1.00 Yes

2.50 7 21.00 117.00 1.00 Yes

3.50 8 21.00 113.00 1.00 Yes

4.50 8 21.00 113.00 1.00 Yes

5.50 8 21.00 113.00 1.00 Yes

6.50 8 21.00 113.00 1.00 Yes

7.50 8 21.00 113.00 1.00 Yes

8.50 21 21.00 120.00 1.00 Yes

9.50 21 21.00 120.00 1.00 Yes

10.50 21 21.00 120.00 1.00 Yes

11.50 21 21.00 120.00 1.00 Yes

12.50 21 21.00 120.00 1.00 Yes

13.50 33 21.00 137.00 1.00 Yes

14.50 33 21.00 137.00 1.00 Yes

15.50 33 21.00 137.00 1.00 Yes

16.50 33 21.00 137.00 1.00 Yes

17.50 33 9.00 120.00 1.00 Yes

18.50 35 9.00 120.00 1.00 Yes

19.50 35 9.00 120.00 1.00 Yes

20.50 35 9.00 120.00 1.00 Yes

21.50 35 9.00 120.00 1.00 Yes

22.50 35 9.00 120.00 1.00 Yes

23.50 41 31.00 120.00 1.00 Yes

24.50 41 31.00 120.00 1.00 Yes

25.50 41 31.00 120.00 1.00 Yes

26.50 41 31.00 120.00 1.00 Yes

27.50 41 31.00 120.00 1.00 Yes

28.50 41 9.00 120.00 1.00 Yes

29.50 41 9.00 120.00 1.00 Yes

30.50 41 9.00 120.00 1.00 Yes

31.50 41 9.00 120.00 1.00 Yes

32.50 41 9.00 120.00 1.00 Yes

33.50 100 9.00 120.00 1.00 Yes
Abbreviations
Depth:

SPT Field Value:

Fines Content:

Unit Weight:

Infl. Thickness:

Can Liquefy:

Depth at which test was performed (ft)
Number of blows per foot
Fines content at test depth (%)
Unit weight at test depth (pcf)
Thickness of the soil layer to be considered in settlements analysis (ft) User defined switch for excluding/including test depth from the analysis procedure :: Cyclic Resistance Ratio (CRR) calculation data ::

CRR7.5Depth
(ft)
SPT
Field
Value
CN CE CB CR CS (N1)60 (N1)60csFC
(%)
σv
(tsf)
uo
(tsf)
σ'vo
(tsf)
Unit
Weight
(pcf)
Δ(Ν1)60m

0.50 7 1.70 1.00 1.15 0.75 1.00 10 15 4.00021.00117.00 0.03 0.00 0.03 0.46 4.63

1.50 7 1.70 1.00 1.15 0.75 1.00 10 15 4.00021.00117.00 0.09 0.00 0.09 0.46 4.63

2.50 7 1.70 1.00 1.15 0.75 1.00 10 15 4.00021.00117.00 0.15 0.00 0.15 0.46 4.63 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 11LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
239
Packet Page 669 of 792

This software is registered to: Earth Systems Pacific
:: Cyclic Resistance Ratio (CRR) calculation data ::

CRR7.5Depth
(ft)
SPT
Field
Value
CN CE CB CR CS (N1)60 (N1)60csFC
(%)
σv
(tsf)
uo
(tsf)
σ'vo
(tsf)
Unit
Weight
(pcf)
Δ(Ν1)60m

3.50 8 1.70 1.00 1.15 0.75 1.00 12 17 4.00021.00113.00 0.20 0.00 0.20 0.44 4.63

4.50 8 1.70 1.00 1.15 0.75 1.00 12 17 4.00021.00113.00 0.26 0.00 0.26 0.44 4.63

5.50 8 1.70 1.00 1.15 0.75 1.00 12 17 4.00021.00113.00 0.32 0.00 0.32 0.44 4.63

6.50 8 1.61 1.00 1.15 0.75 1.00 11 16 4.00021.00113.00 0.37 0.00 0.37 0.45 4.63

7.50 8 1.51 1.00 1.15 0.80 1.00 11 16 4.00021.00113.00 0.43 0.00 0.43 0.46 4.63

8.50 21 1.31 1.00 1.15 0.80 1.00 25 30 0.48521.00120.00 0.49 0.00 0.49 0.35 4.63

9.50 21 1.27 1.00 1.15 0.80 1.00 24 29 0.42921.00120.00 0.55 0.00 0.55 0.36 4.63

10.50 21 1.22 1.00 1.15 0.85 1.00 25 30 0.48521.00120.00 0.61 0.00 0.61 0.36 4.63

11.50 21 1.18 1.00 1.15 0.85 1.00 24 29 0.42921.00120.00 0.67 0.00 0.67 0.36 4.63

12.50 21 1.15 1.00 1.15 0.85 1.00 24 29 0.42921.00120.00 0.73 0.00 0.73 0.37 4.63

13.50 33 1.09 1.00 1.15 0.85 1.00 35 40 4.00021.00137.00 0.80 0.00 0.80 0.30 4.63

14.50 33 1.06 1.00 1.15 0.85 1.00 34 39 4.00021.00137.00 0.87 0.00 0.87 0.30 4.63

15.50 33 1.04 1.00 1.15 0.85 1.00 34 39 4.00021.00137.00 0.93 0.00 0.93 0.31 4.63

16.50 33 1.02 1.00 1.15 0.95 1.00 37 42 4.00021.00137.00 1.00 0.00 1.00 0.29 4.63

17.50 33 1.00 1.00 1.15 0.95 1.00 36 37 4.0009.00120.00 1.06 0.02 1.05 0.32 0.72

18.50 35 0.99 1.00 1.15 0.95 1.00 38 39 4.0009.00120.00 1.12 0.05 1.08 0.31 0.72

19.50 35 0.99 1.00 1.15 0.95 1.00 38 39 4.0009.00120.00 1.18 0.08 1.10 0.31 0.72

20.50 35 0.98 1.00 1.15 0.95 1.00 37 38 4.0009.00120.00 1.24 0.11 1.13 0.31 0.72

21.50 35 0.97 1.00 1.15 0.95 1.00 37 38 4.0009.00120.00 1.30 0.14 1.16 0.31 0.72

22.50 35 0.96 1.00 1.15 0.95 1.00 37 38 4.0009.00120.00 1.36 0.17 1.19 0.31 0.72

23.50 41 0.96 1.00 1.15 0.95 1.00 43 48 4.00031.00120.00 1.42 0.20 1.22 0.26 5.40

24.50 41 0.96 1.00 1.15 0.95 1.00 43 48 4.00031.00120.00 1.48 0.23 1.25 0.26 5.40

25.50 41 0.95 1.00 1.15 0.95 1.00 43 48 4.00031.00120.00 1.54 0.27 1.28 0.26 5.40

26.50 41 0.95 1.00 1.15 0.95 1.00 42 47 4.00031.00120.00 1.60 0.30 1.31 0.26 5.40

27.50 41 0.94 1.00 1.15 0.95 1.00 42 47 4.00031.00120.00 1.66 0.33 1.34 0.26 5.40

28.50 41 0.93 1.00 1.15 0.95 1.00 42 43 4.0009.00120.00 1.72 0.36 1.36 0.28 0.72

29.50 41 0.92 1.00 1.15 0.95 1.00 41 42 4.0009.00120.00 1.78 0.39 1.39 0.29 0.72

30.50 41 0.92 1.00 1.15 1.00 1.00 43 44 4.0009.00120.00 1.84 0.42 1.42 0.27 0.72

31.50 41 0.92 1.00 1.15 1.00 1.00 43 44 4.0009.00120.00 1.90 0.45 1.45 0.28 0.72

32.50 41 0.91 1.00 1.15 1.00 1.00 43 44 4.0009.00120.00 1.96 0.48 1.48 0.28 0.72

33.50 100 0.91 1.00 1.15 1.00 1.00 105 106 4.0009.00120.00 2.02 0.51 1.51 0.26 0.72 σv:
uo:
σ'vo:
m:

CN:

CE:

CB:

CR:

CS:

N1(60):

Δ(Ν1)60
N1 (60) cs:

CRR7.5:

Total stress during SPT test (tsf)
Water pore pressure during SPT test (tsf)
Effective overburden pressure during SPT test (tsf)
Stress exponent normalization factor
Overburden corretion factor
Energy correction factor
Borehole diameter correction factor
Rod length correction factor
Liner correction factor
Corrected N SPT to a 60% energy ratio
Equivalent clean sand adjustment
Corected N1(60) value for fines content
Cyclic resistance ratio for M=7.5
Abbreviations
σv , e q
(tsf)
rd CSR MSF CSRe q,M =7.5Ksi gma CSR*
:: Cyclic Stress Ratio calculation (CSR fully adjusted and normalized) ::

Depth
(ft)
Unit
Weight
(pcf)
uo, e q
(tsf)
σ'v o,eq
(tsf)
FSMSFma x (N1)60csα

0.50 117.00 0.03 0.00 0.03 1.01 0.758 0.97 0.782 1.10 0.711 2.0001.32 151.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 12LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
240
Packet Page 670 of 792

This software is registered to: Earth Systems Pacific
σv , e q
(tsf)
rd CSR MSF CSRe q,M =7.5Ksi gma CSR*
:: Cyclic Stress Ratio calculation (CSR fully adjusted and normalized) ::

Depth
(ft)
Unit
Weight
(pcf)
uo, e q
(tsf)
σ'v o,eq
(tsf)
FSMSFma x (N1)60csα

1.50 117.00 0.09 0.00 0.09 1.00 0.757 0.97 0.780 1.10 0.709 2.0001.32 151.00

2.50 117.00 0.15 0.00 0.15 1.00 0.755 0.97 0.779 1.10 0.708 2.0001.32 151.00

3.50 113.00 0.20 0.00 0.20 1.00 0.754 0.96 0.782 1.10 0.711 2.0001.38 171.00

4.50 113.00 0.26 0.00 0.26 1.00 0.752 0.96 0.781 1.10 0.710 2.0001.38 171.00

5.50 113.00 0.32 0.00 0.32 1.00 0.751 0.96 0.779 1.10 0.709 2.0001.38 171.00

6.50 113.00 0.37 0.00 0.37 0.99 0.749 0.97 0.775 1.10 0.705 2.0001.35 161.00

7.50 113.00 0.43 0.00 0.43 0.99 0.748 0.97 0.774 1.10 0.703 2.0001.35 161.00

8.50 120.00 0.49 0.02 0.47 0.99 0.771 0.90 0.852 1.10 0.775 0.6262.00 301.00

9.50 120.00 0.55 0.05 0.50 0.99 0.814 0.91 0.894 1.10 0.813 0.5281.94 291.00

10.50 120.00 0.61 0.08 0.53 0.98 0.852 0.90 0.942 1.10 0.856 0.5662.00 301.00

11.50 120.00 0.67 0.11 0.56 0.98 0.885 0.91 0.973 1.10 0.884 0.4851.94 291.00

12.50 120.00 0.73 0.14 0.59 0.98 0.915 0.91 1.005 1.10 0.914 0.4691.94 291.00

13.50 137.00 0.80 0.17 0.63 0.98 0.939 0.89 1.061 1.10 0.965 2.0002.20 401.00

14.50 137.00 0.87 0.20 0.66 0.97 0.960 0.89 1.084 1.10 0.986 2.0002.20 391.00

15.50 137.00 0.93 0.23 0.70 0.97 0.978 0.89 1.105 1.10 1.004 2.0002.20 391.00

16.50 137.00 1.00 0.27 0.74 0.97 0.994 0.89 1.123 1.10 1.021 2.0002.20 421.00

17.50 120.00 1.06 0.30 0.77 0.97 1.011 0.89 1.142 1.10 1.043 2.0002.20 371.00

18.50 120.00 1.12 0.33 0.80 0.96 1.026 0.89 1.159 1.08 1.069 2.0002.20 391.00

19.50 120.00 1.18 0.36 0.82 0.96 1.040 0.89 1.175 1.07 1.094 2.0002.20 391.00

20.50 120.00 1.24 0.39 0.85 0.96 1.052 0.89 1.189 1.06 1.118 2.0002.20 381.00

21.50 120.00 1.30 0.42 0.88 0.95 1.064 0.89 1.202 1.05 1.140 2.0002.20 381.00

22.50 120.00 1.36 0.45 0.91 0.95 1.074 0.89 1.213 1.04 1.162 2.0002.20 381.00

23.50 120.00 1.42 0.48 0.94 0.95 1.083 0.89 1.224 1.04 1.182 2.0002.20 481.00

24.50 120.00 1.48 0.51 0.97 0.95 1.092 0.89 1.233 1.03 1.202 2.0002.20 481.00

25.50 120.00 1.54 0.55 1.00 0.94 1.099 0.89 1.242 1.02 1.220 2.0002.20 481.00

26.50 120.00 1.60 0.58 1.03 0.94 1.106 0.89 1.250 1.01 1.238 2.0002.20 471.00

27.50 120.00 1.66 0.61 1.05 0.94 1.112 0.89 1.257 1.00 1.255 2.0002.20 471.00

28.50 120.00 1.72 0.64 1.08 0.93 1.118 0.89 1.263 0.99 1.271 2.0002.20 431.00

29.50 120.00 1.78 0.67 1.11 0.93 1.122 0.89 1.268 0.99 1.287 2.0002.20 421.00

30.50 120.00 1.84 0.70 1.14 0.93 1.127 0.89 1.273 0.98 1.302 2.0002.20 441.00

31.50 120.00 1.90 0.73 1.17 0.92 1.130 0.89 1.277 0.97 1.316 2.0002.20 441.00

32.50 120.00 1.96 0.76 1.20 0.92 1.134 0.89 1.281 0.96 1.330 2.0002.20 441.00

33.50 120.00 2.02 0.80 1.23 0.91 1.136 0.89 1.284 0.96 1.343 2.0002.20 1061.00 σv, eq:
uo, eq:
σ'vo, eq:
rd:
α:

CSR :

MSF :

CSReq, M=7. 5:

Ksigma:

CSR*:

FS:

Total overburden pressure at test point, during earthquake (tsf) Water pressure at test point, during earthquake (tsf)
Effective overburden pressure, during earthquake (tsf)
Nonlinear shear mass factor
Improvement factor due to stone columns
Cyclic Stress Ratio
Magnitude Scaling Factor
CSR adjusted for M=7.5
Effective overburden stress factor
CSR fully adjusted (user FS applied)***
Calculated factor of safety against soil liquefaction
Abbreviations

1.00* ** User FS:
:: Liquefaction potential according to Iwasaki ::

Depth
(ft)
FS F Thickness
(ft)
wz IL
Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 13LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
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Packet Page 671 of 792

This software is registered to: Earth Systems Pacific
:: Liquefaction potential according to Iwasaki ::

Depth
(ft)
FS F Thickness
(ft)
wz IL

0.50 2.000 0.00 9.92 0.001.00

1.50 2.000 0.00 9.77 0.001.00

2.50 2.000 0.00 9.62 0.001.00

3.50 2.000 0.00 9.47 0.001.00

4.50 2.000 0.00 9.31 0.001.00

5.50 2.000 0.00 9.16 0.001.00

6.50 2.000 0.00 9.01 0.001.00

7.50 2.000 0.00 8.86 0.001.00

8.50 0.626 0.37 8.70 0.991.00

9.50 0.528 0.47 8.55 1.231.00

10.50 0.566 0.43 8.40 1.111.00

11.50 0.485 0.51 8.25 1.291.00

12.50 0.469 0.53 8.10 1.311.00

13.50 2.000 0.00 7.94 0.001.00

14.50 2.000 0.00 7.79 0.001.00

15.50 2.000 0.00 7.64 0.001.00

16.50 2.000 0.00 7.49 0.001.00

17.50 2.000 0.00 7.33 0.001.00

18.50 2.000 0.00 7.18 0.001.00

19.50 2.000 0.00 7.03 0.001.00

20.50 2.000 0.00 6.88 0.001.00

21.50 2.000 0.00 6.72 0.001.00

22.50 2.000 0.00 6.57 0.001.00

23.50 2.000 0.00 6.42 0.001.00

24.50 2.000 0.00 6.27 0.001.00

25.50 2.000 0.00 6.11 0.001.00

26.50 2.000 0.00 5.96 0.001.00

27.50 2.000 0.00 5.81 0.001.00

28.50 2.000 0.00 5.66 0.001.00

29.50 2.000 0.00 5.50 0.001.00

30.50 2.000 0.00 5.35 0.001.00

31.50 2.000 0.00 5.20 0.001.00

32.50 2.000 0.00 5.05 0.001.00

33.50 2.000 0.00 4.89 0.001.00

5.94 IL = 0.00 - No liquefaction
IL between 0.00 and 5 - Liquefaction not probable
IL between 5 and 15 - Liquefaction probable
IL > 15 - Liquefaction certain
Overall potential I L :
:: Vertical settlements estimation for dry sands ::

Depth
(ft)
(N1)60 τav p Gma x
(tsf)
α b γ ε15 Nc εNc
(% )
ΔS
(in)
Δh
(ft)

0.50 10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

1.50 10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

2.50 10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

3.50 12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 14LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

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This software is registered to: Earth Systems Pacific
:: Vertical settlements estimation for dry sands ::

Depth
(ft)
(N1)60 τav p Gma x
(tsf)
α b γ ε15 Nc εNc
(% )
ΔS
(in)
Δh
(ft)

4.50 12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

5.50 12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

6.50 11 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00

7.50 11 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0001.00 Abbreviations
τav:
p:

Gmax:
α, b:
γ:
ε15:

Nc:
εNc:

Δh:

ΔS:

Average cyclic shear stress
Average stress
Maximum shear modulus (tsf)
Shear strain formula variables
Average shear strain
Volumetric strain after 15 cycles
Number of cycles
Volumetric strain for number of cycles Nc (%)
Thickness of soil layer (in)
Settlement of soil layer (in)

0.000Cumulative settlemetns:
:: Vertical & Lateral displ.acements estimation for saturated sands ::

Depth
(ft)
γl im
(% )
ev
(% )
dz
(ft)
Sv-1D
(in)
(N1)60cs Fα γmax
(% )
FSliq LDI
(ft)

8.50 30 4.65 -0.09 0.626 4.65 0.92 1.00 0.111 0.00

9.50 29 5.33 -0.02 0.528 5.33 1.10 1.00 0.131 0.00

10.50 30 4.65 -0.09 0.566 4.65 0.92 1.00 0.111 0.00

11.50 29 5.33 -0.02 0.485 5.33 1.10 1.00 0.131 0.00

12.50 29 5.33 -0.02 0.469 5.33 1.10 1.00 0.131 0.00

13.50 40 0.87 -0.80 2.000 0.00 0.00 1.00 0.000 0.00

14.50 39 1.07 -0.73 2.000 0.00 0.00 1.00 0.000 0.00

15.50 39 1.07 -0.73 2.000 0.00 0.00 1.00 0.000 0.00

16.50 42 0.56 -0.96 2.000 0.00 0.00 1.00 0.000 0.00

17.50 37 1.56 -0.58 2.000 0.00 0.00 1.00 0.000 0.00

18.50 39 1.07 -0.73 2.000 0.00 0.00 1.00 0.000 0.00

19.50 39 1.07 -0.73 2.000 0.00 0.00 1.00 0.000 0.00

20.50 38 1.30 -0.65 2.000 0.00 0.00 1.00 0.000 0.00

21.50 38 1.30 -0.65 2.000 0.00 0.00 1.00 0.000 0.00

22.50 38 1.30 -0.65 2.000 0.00 0.00 1.00 0.000 0.00

23.50 48 0.09 -1.43 2.000 0.00 0.00 1.00 0.000 0.00

24.50 48 0.09 -1.43 2.000 0.00 0.00 1.00 0.000 0.00

25.50 48 0.09 -1.43 2.000 0.00 0.00 1.00 0.000 0.00

26.50 47 0.13 -1.35 2.000 0.00 0.00 1.00 0.000 0.00

27.50 47 0.13 -1.35 2.000 0.00 0.00 1.00 0.000 0.00

28.50 43 0.44 -1.03 2.000 0.00 0.00 1.00 0.000 0.00

29.50 42 0.56 -0.96 2.000 0.00 0.00 1.00 0.000 0.00

30.50 44 0.34 -1.11 2.000 0.00 0.00 1.00 0.000 0.00

31.50 44 0.34 -1.11 2.000 0.00 0.00 1.00 0.000 0.00

32.50 44 0.34 -1.11 2.000 0.00 0.00 1.00 0.000 0.00

33.50 106 0.00 -6.64 2.000 0.00 0.00 1.00 0.000 0.00
Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 15LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

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This software is registered to: Earth Systems Pacific
:: Vertical & Lateral displ.acements estimation for saturated sands ::

Depth
(ft)
γl im
(% )
ev
(% )
dz
(ft)
Sv-1D
(in)
(N1)60cs Fα γmax
(% )
FSliq LDI
(ft)
Abbreviations

0.616Cumulative settlements:
γlim:

Fα/N:
γm ax:
ev::

Sv-1D:

LDI:

Limiting shear strain (%)
Maximun shear strain factor
Maximum shear strain (%)
Post liquefaction volumetric strain (%)
Estimated vertical settlement (in)
Estimated lateral displacement (ft)

0.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\liq anaylsis.lsvs Page: 16LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

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References
⦁ Ronald D. Andrus, Hossein Hayati, Nisha P. Mohanan, 2009. Correcting Liquefaction Resistance for Aged Sands Using Measured to Estimated Velocity Ratio, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 135, No. 6, June 1 ⦁ Boulanger, R.W. and Idriss, I. M., 20 14. CPT AND SPT BASED LIQUEFACTION TRIGGERING PROCEDURES. DEPARTMENT OF

CIVIL & ENVIRONMENTAL ENGINEERING COLLEGE OF ENGINEERING UNIVERSITY OF CALIFORNIA AT DAVIS ⦁ Dipl.-Ing. Heinz J. Priebe, Vibro Replacement to Prevent Earthquake Induced Liquefaction, Proceedings of the Geotechnique- Colloquium at Darmstadt, Germany, on March 19th, 1998 (also published in Ground Engineering, September 1998), Technical paper 12-57E
⦁ Robertson, P.K. and Cabal, K.L., 2007 , Guide to Cone Penetration Testing for Geotechnical Engineering. Available at no cost at http://www.geologismiki.gr/
⦁ Youd, T.L., Idriss, I.M., Andrus, R.D., Arango, I., Castro, G., Christian, J.T., Dobry, R., Finn, W.D.L., Harder, L.F., Hynes , M.E., Ishihara, K., Koester, J., Liao, S., Marcuson III, W.F., Martin, G.R., Mitchell, J.K., Moriwaki, Y., Power, M.S., Robertson, P.K., Seed, R., and Stokoe, K.H., Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshop on Evaluation of Liquefaction Resistance of Soils, ASCE, Journal of Geotechnical & Geoenvironmental Engineering, Vol. 127, October, pp 817-833
⦁ Zhang, G., Robertson. P.K., Brachman, R., 2002, Estimating Liquefaction Induced Ground Settlements from the CPT, Canadian Geotechnical Journal, 39: pp 1168-1180
⦁ Zhang, G., Robertson. P.K., Brachman, R., 2004, Estimating Liquefaction Induced Lateral Displacements using the SPT and CPT, ASCE, Journal of Geotechnical & Geoenvironmental Engineering, Vol. 130, No. 8, 861-871 ⦁ Pradel, D., 1998, Procedure to Evaluate Earthquake -Induced Settlements in Dry Sandy Soils, ASCE, Journal of Geotechnical & Geoenvironmental Engineering, Vol. 124, No. 4, 364-368
⦁ R. Kayen, R. E. S. Moss, E. M. Thompson, R. B. Seed, K. O. Cetin, A. Der Kiureghian, Y. Tanaka, K. Tokimatsu, 2013. Shear- Wave Velocity–Based Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Potential, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 139, No. 3, March 1 LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

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S P T B A S ED L IQ UEFA C TIO N A NA L YS IS R EP O R T :: Input parameters and analysis properties ::

Analysis method:

Fines correction method:

Sampling method:

Borehole diameter:

Rod length:

Hammer energy ratio:

Boulanger & Idriss, 2014
Boulanger & Idriss, 2014
Standard Sampler
200mm

3.30 ft

1.00 G.W.T. (in-situ):

G.W.T. (earthq.):

Earthquake magnitude Mw:

Peak ground acceleration:

Eq. external load:

Project title : 575 Los Trancos Road Residence, Dry Sand Location : Palo Alto, California
SPT Name: B-1

18.00 ft

8.00 ft

7.80 0.77 g

0.00 tsf
Raw SPT Data
SPT Count (blows/ft)
50403020100
Depth (ft)
8 7
6 5
4 3
2 1
Raw SPT Data
Insitu
CSR - CRR Plot

CSR - CRR

10.80.60.40.20 Depth (ft)

8.5 8

7.5 7

6.5 6

5.5 5

4.5 4

3.5 3

2.5 2

1.5 1

0.5 CSR - CRR Plot
During earthq.

FS Plot
Factor of Safety

21.510.50
Depth (ft)

8.5 8

7.5 7

6.5 6

5.5 5

4.5 4

3.5 3

2.5 2

1.5 1

0.5 FS Plot
During earthq.

LPI
Liquefaction potential
0 Depth (ft)

8.5 8

7.5 7

6.5 6

5.5 5

4.5 4

3.5 3

2.5 2

1.5 1

0.5 LPI
During earthq.

CRR 7.50 clean sand curve
Corrected Blow Count N1(60),cs
50454035302520151050
Cyclic Stress Ratio*

0.8 0.7

0.6 0.5

0.4 0.3

0.2 0.1

0.0 CRR 7.50 clean sand curve
Liquefaction
No Liquefaction
F.S. color scheme
Almost certain it will liquefy
Very likely to liquefy
Liquefaction and no liq. are equally likely
Unlike to liquefy
Almost certain it will not liquefy
LPI color scheme
Very high risk
High risk
Low risk
Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\dry sand anaylsis.lsvs Page: 1LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

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This software is registered to: Earth Systems Pacific
Raw SPT Data
SPT Count (blows/ft)
50403020100
Depth (ft)
8 7
6 5
4 3
2 1
Raw SPT Data
Insitu
CSR - CRR Plot

CSR - CRR

10.80.60.40.20 Depth (ft)

8.4 8.2
8 7.8

7.6 7.4

7.2 7

6.8 6.6

6.4 6.2
6 5.8

5.6 5.4

5.2 5

4.8 4.6

4.4 4.2
4 3.8

3.6 3.4

3.2 3

2.8 2.6

2.4 2.2
2 1.8

1.6 1.4

1.2 1

0.8 0.6
CSR - CRR Plot
During earthq.

FS Plot
Factor of Safety

21.510.50
Depth (ft)

8.4 8.2
8 7.8

7.6 7.4

7.2 7

6.8 6.6

6.4 6.2
6 5.8

5.6 5.4

5.2 5

4.8 4.6

4.4 4.2
4 3.8

3.6 3.4

3.2 3

2.8 2.6

2.4 2.2
2 1.8

1.6 1.4

1.2 1

0.8 0.6
FS Plot
During earthq.

Vertical Liq. Settlements
Cuml. Settlement (in)

0.20.10 Depth (ft)

8.4 8.2
8 7.8

7.6 7.4

7.2 7

6.8 6.6

6.4 6.2
6 5.8

5.6 5.4

5.2 5

4.8 4.6

4.4 4.2
4 3.8

3.6 3.4

3.2 3

2.8 2.6

2.4 2.2
2 1.8

1.6 1.4

1.2 1

0.8 0.6
Vertical Liq. Settlements
During earthq.

Lateral Liq. Displacements
Cuml. Displacement (ft)
0 Depth (ft)

8.4 8.2
8 7.8

7.6 7.4

7.2 7

6.8 6.6

6.4 6.2
6 5.8

5.6 5.4

5.2 5

4.8 4.6

4.4 4.2
4 3.8

3.6 3.4

3.2 3

2.8 2.6

2.4 2.2
2 1.8

1.6 1.4

1.2 1

0.8 0.6
Lateral Liq. Displacements
During earthq.
:: Overall Liquefaction Assessment Analysis Plots ::

Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\dry sand anaylsis.lsvs Page: 2LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
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This software is registered to: Earth Systems Pacific
Test
Depth
(ft)
:: Field input data ::

SPT Field
Value
(blows)
Fines
Content
(%)
Unit
Weight
(pcf)
Infl.

Thickness
(ft)
Can
Liquefy

0.50 16 5.00 116.00 1.00 Yes

1.50 16 5.00 116.00 1.00 Yes

2.50 16 5.00 116.00 1.00 Yes

3.50 12 5.00 122.00 1.00 Yes

4.50 12 5.00 122.00 1.00 Yes

5.50 12 18.00 122.00 1.00 Yes

6.50 12 18.00 122.00 1.00 Yes

7.50 43 18.00 120.00 1.00 No

8.50 43 18.00 120.00 1.00 No
Abbreviations
Depth:

SPT Field Value:

Fines Content:

Unit Weight:

Infl. Thickness:

Can Liquefy:

Depth at which test was performed (ft)
Number of blows per foot
Fines content at test depth (%)
Unit weight at test depth (pcf)
Thickness of the soil layer to be considered in settlements analysis (ft) User defined switch for excluding/including test depth from the analysis procedure :: Cyclic Resistance Ratio (CRR) calculation data ::

CRR7.5Depth
(ft)
SPT
Field
Value
CN CE CB CR CS (N1)60 (N1)60csFC
(%)
σv
(tsf)
uo
(tsf)
σ'vo
(tsf)
Unit
Weight
(pcf)
Δ(Ν1)60m

0.50 16 1.70 1.00 1.15 0.75 1.00 23 23 4.0005.00116.00 0.03 0.00 0.03 0.41 0.00

1.50 16 1.70 1.00 1.15 0.75 1.00 23 23 4.0005.00116.00 0.09 0.00 0.09 0.41 0.00

2.50 16 1.70 1.00 1.15 0.75 1.00 23 23 4.0005.00116.00 0.15 0.00 0.15 0.41 0.00

3.50 12 1.70 1.00 1.15 0.75 1.00 18 18 4.0005.00122.00 0.21 0.00 0.21 0.46 0.00

4.50 12 1.70 1.00 1.15 0.75 1.00 18 18 4.0005.00122.00 0.27 0.00 0.27 0.46 0.00

5.50 12 1.62 1.00 1.15 0.75 1.00 17 21 4.00018.00122.00 0.33 0.00 0.33 0.41 4.09

6.50 12 1.53 1.00 1.15 0.75 1.00 16 20 4.00018.00122.00 0.39 0.00 0.39 0.42 4.09

7.50 43 1.25 1.00 1.15 0.80 1.00 50 54 4.00018.00120.00 0.45 0.00 0.45 0.26 4.09

8.50 43 1.21 1.00 1.15 0.80 1.00 48 52 4.00018.00120.00 0.51 0.00 0.51 0.26 4.09 σv:
uo:
σ'vo:
m:

CN:

CE:

CB:

CR:

CS:

N1(60):

Δ(Ν1)60
N1 (60) cs:

CRR7.5:

Total stress during SPT test (tsf)
Water pore pressure during SPT test (tsf)
Effective overburden pressure during SPT test (tsf)
Stress exponent normalization factor
Overburden corretion factor
Energy correction factor
Borehole diameter correction factor
Rod length correction factor
Liner correction factor
Corrected N SPT to a 60% energy ratio
Equivalent clean sand adjustment
Corected N1(60) value for fines content
Cyclic resistance ratio for M=7.5
Abbreviations
σv , e q
(tsf)
rd CSR MSF CSRe q,M =7.5Ksi gma CSR*
:: Cyclic Stress Ratio calculation (CSR fully adjusted and normalized) ::

Depth
(ft)
Unit
Weight
(pcf)
uo, e q
(tsf)
σ'v o,eq
(tsf)
FSMSFma x (N1)60csα

0.50 116.00 0.03 0.00 0.03 1.01 0.503 0.94 0.535 1.10 0.486 2.0001.62 231.00

1.50 116.00 0.09 0.00 0.09 1.00 0.502 0.94 0.534 1.10 0.486 2.0001.62 231.00

2.50 116.00 0.15 0.00 0.15 1.00 0.501 0.94 0.533 1.10 0.485 2.0001.62 231.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\dry sand anaylsis.lsvs Page: 3LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

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This software is registered to: Earth Systems Pacific
σv , e q
(tsf)
rd CSR MSF CSRe q,M =7.5Ksi gma CSR*
:: Cyclic Stress Ratio calculation (CSR fully adjusted and normalized) ::

Depth
(ft)
Unit
Weight
(pcf)
uo, e q
(tsf)
σ'v o,eq
(tsf)
FSMSFma x (N1)60csα

3.50 122.00 0.21 0.00 0.21 1.00 0.500 0.96 0.521 1.10 0.474 2.0001.42 181.00

4.50 122.00 0.27 0.00 0.27 1.00 0.499 0.96 0.520 1.10 0.473 2.0001.42 181.00

5.50 122.00 0.33 0.00 0.33 1.00 0.498 0.95 0.525 1.10 0.478 2.0001.53 211.00

6.50 122.00 0.39 0.00 0.39 0.99 0.497 0.95 0.522 1.10 0.475 2.0001.49 201.00

7.50 120.00 0.45 0.00 0.45 0.99 0.496 0.89 0.561 1.10 0.510 2.0002.20 541.00

8.50 120.00 0.51 0.02 0.49 0.99 0.511 0.89 0.577 1.10 0.525 2.0002.20 521.00 σv, eq:
uo, eq:
σ'vo, eq:
rd:
α:

CSR :

MSF :

CSReq, M=7. 5:

Ksigma:

CSR*:

FS:

Total overburden pressure at test point, during earthquake (tsf) Water pressure at test point, during earthquake (tsf)
Effective overburden pressure, during earthquake (tsf)
Nonlinear shear mass factor
Improvement factor due to stone columns
Cyclic Stress Ratio
Magnitude Scaling Factor
CSR adjusted for M=7.5
Effective overburden stress factor
CSR fully adjusted (user FS applied)***
Calculated factor of safety against soil liquefaction
Abbreviations

1.00* ** User FS:
:: Liquefaction potential according to Iwasaki ::

Depth
(ft)
FS F Thickness
(ft)
wz IL

0.50 2.000 0.00 9.92 0.001.00

1.50 2.000 0.00 9.77 0.001.00

2.50 2.000 0.00 9.62 0.001.00

3.50 2.000 0.00 9.47 0.001.00

4.50 2.000 0.00 9.31 0.001.00

5.50 2.000 0.00 9.16 0.001.00

6.50 2.000 0.00 9.01 0.001.00

7.50 2.000 0.00 8.86 0.001.00

8.50 2.000 0.00 8.70 0.001.00

0.00 IL = 0.00 - No liquefaction
IL between 0.00 and 5 - Liquefaction not probable
IL between 5 and 15 - Liquefaction probable
IL > 15 - Liquefaction certain
Overall potential I L :
:: Vertical settlements estimation for dry sands ::

Depth
(ft)
(N1)60 τav p Gma x
(tsf)
α b γ ε15 Nc εNc
(% )
ΔS
(in)
Δh
(ft)

0.50 23 0.01 0.02 0.18 0.13 53547.74 0.00 0.00 18.12 0.08 0.0181.00

1.50 23 0.04 0.06 0.31 0.13 27699.28 0.00 0.00 18.12 0.09 0.0211.00

2.50 23 0.07 0.10 0.40 0.13 20387.27 0.00 0.00 18.12 0.10 0.0231.00

3.50 18 0.10 0.14 0.44 0.13 16514.28 0.00 0.00 18.12 0.20 0.0471.00

4.50 18 0.13 0.18 0.50 0.13 14134.26 0.00 0.00 18.12 0.21 0.0491.00

5.50 17 0.16 0.22 0.58 0.14 12492.68 0.00 0.00 18.12 0.15 0.0351.00

6.50 16 0.19 0.26 0.62 0.14 11277.43 0.00 0.00 18.12 0.17 0.0411.00

7.50 50 0.22 0.30 0.93 0.14 10347.42 0.00 0.00 18.12 0.02 0.0051.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\dry sand anaylsis.lsvs Page: 4LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
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This software is registered to: Earth Systems Pacific
:: Vertical settlements estimation for dry sands ::

Depth
(ft)
(N1)60 τav p Gma x
(tsf)
α b γ ε15 Nc εNc
(% )
ΔS
(in)
Δh
(ft)
Abbreviations
τav:
p:

Gmax:
α, b:
γ:
ε15:

Nc:
εNc:

Δh:

ΔS:

Average cyclic shear stress
Average stress
Maximum shear modulus (tsf)
Shear strain formula variables
Average shear strain
Volumetric strain after 15 cycles
Number of cycles
Volumetric strain for number of cycles Nc (%)
Thickness of soil layer (in)
Settlement of soil layer (in)

0.239Cumulative settlemetns:
:: Vertical & Lateral displ.acements estimation for saturated sands ::

Depth
(ft)
γl im
(% )
ev
(% )
dz
(ft)
Sv-1D
(in)
(N1)60cs Fα γmax
(% )
FSliq LDI
(ft)

8.50 52 0.00 0.00 2.000 0.00 0.00 1.00 0.000 0.00
Abbreviations

0.000Cumulative settlements:
γlim:

Fα/N:
γm ax:
ev::

Sv-1D:

LDI:

Limiting shear strain (%)
Maximun shear strain factor
Maximum shear strain (%)
Post liquefaction volumetric strain (%)
Estimated vertical settlement (in)
Estimated lateral displacement (ft)

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Attachment E 575 Los Trancos Road
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S P T B A S ED L IQ UEFA C TIO N A NA L YS IS R EP O R T :: Input parameters and analysis properties ::

Analysis method:

Fines correction method:

Sampling method:

Borehole diameter:

Rod length:

Hammer energy ratio:

Boulanger & Idriss, 2014
Boulanger & Idriss, 2014
Standard Sampler
200mm

3.30 ft

1.00 G.W.T. (in-situ):

G.W.T. (earthq.):

Earthquake magnitude Mw:

Peak ground acceleration:

Eq. external load:

Project title : 575 Los Trancos Road Residence, Dry Sand Location : Palo Alto, California
SPT Name: B-2

17.00 ft

8.00 ft

7.80 0.77 g

0.00 tsf
Raw SPT Data
SPT Count (blows/ft)
50403020100
Depth (ft)
8 7
6 5
4 3
2 1
Raw SPT Data
Insitu
CSR - CRR Plot

CSR - CRR

10.80.60.40.20 Depth (ft)

8.5 8

7.5 7

6.5 6

5.5 5

4.5 4

3.5 3

2.5 2

1.5 1

0.5 CSR - CRR Plot
During earthq.

FS Plot
Factor of Safety

21.510.50
Depth (ft)

8.5 8

7.5 7

6.5 6

5.5 5

4.5 4

3.5 3

2.5 2

1.5 1

0.5 FS Plot
During earthq.

LPI
Liquefaction potential
0 Depth (ft)

8.5 8

7.5 7

6.5 6

5.5 5

4.5 4

3.5 3

2.5 2

1.5 1

0.5 LPI
During earthq.

CRR 7.50 clean sand curve
Corrected Blow Count N1(60),cs
50454035302520151050
Cyclic Stress Ratio*

0.8 0.7

0.6 0.5

0.4 0.3

0.2 0.1

0.0 CRR 7.50 clean sand curve
Liquefaction
No Liquefaction
F.S. color scheme
Almost certain it will liquefy
Very likely to liquefy
Liquefaction and no liq. are equally likely
Unlike to liquefy
Almost certain it will not liquefy
LPI color scheme
Very high risk
High risk
Low risk
Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\dry sand anaylsis.lsvs Page: 6LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

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This software is registered to: Earth Systems Pacific
Raw SPT Data
SPT Count (blows/ft)
50403020100
Depth (ft)
8 7
6 5
4 3
2 1
Raw SPT Data
Insitu
CSR - CRR Plot

CSR - CRR

10.80.60.40.20 Depth (ft)

8.4 8.2
8 7.8

7.6 7.4

7.2 7

6.8 6.6

6.4 6.2
6 5.8

5.6 5.4

5.2 5

4.8 4.6

4.4 4.2
4 3.8

3.6 3.4

3.2 3

2.8 2.6

2.4 2.2
2 1.8

1.6 1.4

1.2 1

0.8 0.6
CSR - CRR Plot
During earthq.

FS Plot
Factor of Safety

21.510.50
Depth (ft)

8.4 8.2
8 7.8

7.6 7.4

7.2 7

6.8 6.6

6.4 6.2
6 5.8

5.6 5.4

5.2 5

4.8 4.6

4.4 4.2
4 3.8

3.6 3.4

3.2 3

2.8 2.6

2.4 2.2
2 1.8

1.6 1.4

1.2 1

0.8 0.6
FS Plot
During earthq.

Vertical Liq. Settlements
Cuml. Settlement (in)

0.40.20 Depth (ft)

8.4 8.2
8 7.8

7.6 7.4

7.2 7

6.8 6.6

6.4 6.2
6 5.8

5.6 5.4

5.2 5

4.8 4.6

4.4 4.2
4 3.8

3.6 3.4

3.2 3

2.8 2.6

2.4 2.2
2 1.8

1.6 1.4

1.2 1

0.8 0.6
Vertical Liq. Settlements
During earthq.

Lateral Liq. Displacements
Cuml. Displacement (ft)
0 Depth (ft)

8.4 8.2
8 7.8

7.6 7.4

7.2 7

6.8 6.6

6.4 6.2
6 5.8

5.6 5.4

5.2 5

4.8 4.6

4.4 4.2
4 3.8

3.6 3.4

3.2 3

2.8 2.6

2.4 2.2
2 1.8

1.6 1.4

1.2 1

0.8 0.6
Lateral Liq. Displacements
During earthq.
:: Overall Liquefaction Assessment Analysis Plots ::

Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\dry sand anaylsis.lsvs Page: 7LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road Residential
Project Final IS-MND with Appendices

Item 13:

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This software is registered to: Earth Systems Pacific
Test
Depth
(ft)
:: Field input data ::

SPT Field
Value
(blows)
Fines
Content
(%)
Unit
Weight
(pcf)
Infl.

Thickness
(ft)
Can
Liquefy

0.50 7 21.00 117.00 1.00 Yes

1.50 7 21.00 117.00 1.00 Yes

2.50 7 21.00 117.00 1.00 Yes

3.50 8 21.00 113.00 1.00 Yes

4.50 8 21.00 113.00 1.00 Yes

5.50 8 21.00 113.00 1.00 Yes

6.50 8 21.00 113.00 1.00 Yes

7.50 8 21.00 113.00 1.00 No

8.50 21 21.00 120.00 1.00 No
Abbreviations
Depth:

SPT Field Value:

Fines Content:

Unit Weight:

Infl. Thickness:

Can Liquefy:

Depth at which test was performed (ft)
Number of blows per foot
Fines content at test depth (%)
Unit weight at test depth (pcf)
Thickness of the soil layer to be considered in settlements analysis (ft) User defined switch for excluding/including test depth from the analysis procedure :: Cyclic Resistance Ratio (CRR) calculation data ::

CRR7.5Depth
(ft)
SPT
Field
Value
CN CE CB CR CS (N1)60 (N1)60csFC
(%)
σv
(tsf)
uo
(tsf)
σ'vo
(tsf)
Unit
Weight
(pcf)
Δ(Ν1)60m

0.50 7 1.70 1.00 1.15 0.75 1.00 10 15 4.00021.00117.00 0.03 0.00 0.03 0.46 4.63

1.50 7 1.70 1.00 1.15 0.75 1.00 10 15 4.00021.00117.00 0.09 0.00 0.09 0.46 4.63

2.50 7 1.70 1.00 1.15 0.75 1.00 10 15 4.00021.00117.00 0.15 0.00 0.15 0.46 4.63

3.50 8 1.70 1.00 1.15 0.75 1.00 12 17 4.00021.00113.00 0.20 0.00 0.20 0.44 4.63

4.50 8 1.70 1.00 1.15 0.75 1.00 12 17 4.00021.00113.00 0.26 0.00 0.26 0.44 4.63

5.50 8 1.70 1.00 1.15 0.75 1.00 12 17 4.00021.00113.00 0.32 0.00 0.32 0.44 4.63

6.50 8 1.61 1.00 1.15 0.75 1.00 11 16 4.00021.00113.00 0.37 0.00 0.37 0.45 4.63

7.50 8 1.51 1.00 1.15 0.80 1.00 11 16 4.00021.00113.00 0.43 0.00 0.43 0.46 4.63

8.50 21 1.31 1.00 1.15 0.80 1.00 25 30 4.00021.00120.00 0.49 0.00 0.49 0.35 4.63 σv:
uo:
σ'vo:
m:

CN:

CE:

CB:

CR:

CS:

N1(60):

Δ(Ν1)60
N1 (60) cs:

CRR7.5:

Total stress during SPT test (tsf)
Water pore pressure during SPT test (tsf)
Effective overburden pressure during SPT test (tsf)
Stress exponent normalization factor
Overburden corretion factor
Energy correction factor
Borehole diameter correction factor
Rod length correction factor
Liner correction factor
Corrected N SPT to a 60% energy ratio
Equivalent clean sand adjustment
Corected N1(60) value for fines content
Cyclic resistance ratio for M=7.5
Abbreviations
σv , e q
(tsf)
rd CSR MSF CSRe q,M =7.5Ksi gma CSR*
:: Cyclic Stress Ratio calculation (CSR fully adjusted and normalized) ::

Depth
(ft)
Unit
Weight
(pcf)
uo, e q
(tsf)
σ'v o,eq
(tsf)
FSMSFma x (N1)60csα

0.50 117.00 0.03 0.00 0.03 1.01 0.503 0.97 0.519 1.10 0.472 2.0001.32 151.00

1.50 117.00 0.09 0.00 0.09 1.00 0.502 0.97 0.518 1.10 0.471 2.0001.32 151.00

2.50 117.00 0.15 0.00 0.15 1.00 0.501 0.97 0.517 1.10 0.470 2.0001.32 151.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\dry sand anaylsis.lsvs Page: 8LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

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This software is registered to: Earth Systems Pacific
σv , e q
(tsf)
rd CSR MSF CSRe q,M =7.5Ksi gma CSR*
:: Cyclic Stress Ratio calculation (CSR fully adjusted and normalized) ::

Depth
(ft)
Unit
Weight
(pcf)
uo, e q
(tsf)
σ'v o,eq
(tsf)
FSMSFma x (N1)60csα

3.50 113.00 0.20 0.00 0.20 1.00 0.500 0.96 0.519 1.10 0.472 2.0001.38 171.00

4.50 113.00 0.26 0.00 0.26 1.00 0.499 0.96 0.518 1.10 0.471 2.0001.38 171.00

5.50 113.00 0.32 0.00 0.32 1.00 0.498 0.96 0.517 1.10 0.470 2.0001.38 171.00

6.50 113.00 0.37 0.00 0.37 0.99 0.497 0.97 0.515 1.10 0.468 2.0001.35 161.00

7.50 113.00 0.43 0.00 0.43 0.99 0.496 0.97 0.513 1.10 0.467 2.0001.35 161.00

8.50 120.00 0.49 0.02 0.47 0.99 0.512 0.90 0.566 1.10 0.514 2.0002.00 301.00 σv, eq:
uo, eq:
σ'vo, eq:
rd:
α:

CSR :

MSF :

CSReq, M=7. 5:

Ksigma:

CSR*:

FS:

Total overburden pressure at test point, during earthquake (tsf) Water pressure at test point, during earthquake (tsf)
Effective overburden pressure, during earthquake (tsf)
Nonlinear shear mass factor
Improvement factor due to stone columns
Cyclic Stress Ratio
Magnitude Scaling Factor
CSR adjusted for M=7.5
Effective overburden stress factor
CSR fully adjusted (user FS applied)***
Calculated factor of safety against soil liquefaction
Abbreviations

1.00* ** User FS:
:: Liquefaction potential according to Iwasaki ::

Depth
(ft)
FS F Thickness
(ft)
wz IL

0.50 2.000 0.00 9.92 0.001.00

1.50 2.000 0.00 9.77 0.001.00

2.50 2.000 0.00 9.62 0.001.00

3.50 2.000 0.00 9.47 0.001.00

4.50 2.000 0.00 9.31 0.001.00

5.50 2.000 0.00 9.16 0.001.00

6.50 2.000 0.00 9.01 0.001.00

7.50 2.000 0.00 8.86 0.001.00

8.50 2.000 0.00 8.70 0.001.00

0.00 IL = 0.00 - No liquefaction
IL between 0.00 and 5 - Liquefaction not probable
IL between 5 and 15 - Liquefaction probable
IL > 15 - Liquefaction certain
Overall potential I L :
:: Vertical settlements estimation for dry sands ::

Depth
(ft)
(N1)60 τav p Gma x
(tsf)
α b γ ε15 Nc εNc
(% )
ΔS
(in)
Δh
(ft)

0.50 10 0.01 0.02 0.15 0.13 53272.67 0.00 0.00 18.12 0.28 0.0661.00

1.50 10 0.04 0.06 0.27 0.13 27556.98 0.00 0.00 18.12 0.29 0.0701.00

2.50 10 0.07 0.10 0.35 0.13 20282.55 0.00 0.00 18.12 0.31 0.0741.00

3.50 12 0.10 0.14 0.42 0.13 16672.60 0.00 0.00 18.12 0.23 0.0551.00

4.50 12 0.13 0.17 0.48 0.13 14386.29 0.00 0.00 18.12 0.24 0.0571.00

5.50 12 0.16 0.21 0.53 0.14 12781.27 0.00 0.00 18.12 0.25 0.0591.00

6.50 11 0.19 0.25 0.56 0.14 11579.22 0.00 0.00 18.12 0.30 0.0721.00

7.50 11 0.21 0.29 0.60 0.14 10637.94 0.00 0.00 18.12 0.31 0.0741.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\dry sand anaylsis.lsvs Page: 9LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

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This software is registered to: Earth Systems Pacific
:: Vertical settlements estimation for dry sands ::

Depth
(ft)
(N1)60 τav p Gma x
(tsf)
α b γ ε15 Nc εNc
(% )
ΔS
(in)
Δh
(ft)
Abbreviations
τav:
p:

Gmax:
α, b:
γ:
ε15:

Nc:
εNc:

Δh:

ΔS:

Average cyclic shear stress
Average stress
Maximum shear modulus (tsf)
Shear strain formula variables
Average shear strain
Volumetric strain after 15 cycles
Number of cycles
Volumetric strain for number of cycles Nc (%)
Thickness of soil layer (in)
Settlement of soil layer (in)

0.527Cumulative settlemetns:
:: Vertical & Lateral displ.acements estimation for saturated sands ::

Depth
(ft)
γl im
(% )
ev
(% )
dz
(ft)
Sv-1D
(in)
(N1)60cs Fα γmax
(% )
FSliq LDI
(ft)

8.50 30 0.00 0.00 2.000 0.00 0.00 1.00 0.000 0.00
Abbreviations

0.000Cumulative settlements:
γlim:

Fα/N:
γm ax:
ev::

Sv-1D:

LDI:

Limiting shear strain (%)
Maximun shear strain factor
Maximum shear strain (%)
Post liquefaction volumetric strain (%)
Estimated vertical settlement (in)
Estimated lateral displacement (ft)

0.00 Project File: \\ad.earthsys.com\shares\Archive\Fremont\PUBLIC\FREMONT FILE FOLDERS\Individual Folders\Phillip\Projects\2021\575 Los Trancos\dry sand anaylsis.lsvs Page: 10LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

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References
⦁ Ronald D. Andrus, Hossein Hayati, Nisha P. Mohanan, 2009. Correcting Liquefaction Resistance for Aged Sands Using Measured to Estimated Velocity Ratio, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 135, No. 6, June 1 ⦁ Boulanger, R.W. and Idriss, I. M., 20 14. CPT AND SPT BASED LIQUEFACTION TRIGGERING PROCEDURES. DEPARTMENT OF

CIVIL & ENVIRONMENTAL ENGINEERING COLLEGE OF ENGINEERING UNIVERSITY OF CALIFORNIA AT DAVIS ⦁ Dipl.-Ing. Heinz J. Priebe, Vibro Replacement to Prevent Earthquake Induced Liquefaction, Proceedings of the Geotechnique- Colloquium at Darmstadt, Germany, on March 19th, 1998 (also published in Ground Engineering, September 1998), Technical paper 12-57E
⦁ Robertson, P.K. and Cabal, K.L., 2007 , Guide to Cone Penetration Testing for Geotechnical Engineering. Available at no cost at http://www.geologismiki.gr/
⦁ Youd, T.L., Idriss, I.M., Andrus, R.D., Arango, I., Castro, G., Christian, J.T., Dobry, R., Finn, W.D.L., Harder, L.F., Hynes , M.E., Ishihara, K., Koester, J., Liao, S., Marcuson III, W.F., Martin, G.R., Mitchell, J.K., Moriwaki, Y., Power, M.S., Robertson, P.K., Seed, R., and Stokoe, K.H., Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshop on Evaluation of Liquefaction Resistance of Soils, ASCE, Journal of Geotechnical & Geoenvironmental Engineering, Vol. 127, October, pp 817-833
⦁ Zhang, G., Robertson. P.K., Brachman, R., 2002, Estimating Liquefaction Induced Ground Settlements from the CPT, Canadian Geotechnical Journal, 39: pp 1168-1180
⦁ Zhang, G., Robertson. P.K., Brachman, R., 2004, Estimating Liquefaction Induced Lateral Displacements using the SPT and CPT, ASCE, Journal of Geotechnical & Geoenvironmental Engineering, Vol. 130, No. 8, 861-871 ⦁ Pradel, D., 1998, Procedure to Evaluate Earthquake -Induced Settlements in Dry Sandy Soils, ASCE, Journal of Geotechnical & Geoenvironmental Engineering, Vol. 124, No. 4, 364-368
⦁ R. Kayen, R. E. S. Moss, E. M. Thompson, R. B. Seed, K. O. Cetin, A. Der Kiureghian, Y. Tanaka, K. Tokimatsu, 2013. Shear- Wave Velocity–Based Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Potential, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 139, No. 3, March 1 LiqSVs 2.0.1.9 - SPT & Vs Liquefaction Assessment Software ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

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A
ppendix D
Roadway Construction Noise Model and Vibration Noise Calculations ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

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Roadway Construction Noise Model (RCNM),Version 1.1
Report date:########
Case Description:575 Los Trancos Road
---- Receptor #1 ----
Baselines (dBA)
DescriptionLand Use Daytime Evening Night
Single Family - NorthResidential 65 60 55
Equipment
Spec Actual Receptor Estimated
Impact Lmax Lmax Distance Shielding
Description Device Usage(%) (dBA) (dBA) (feet) (dBA)
Backhoe No 40 77.6 230 0
Compactor (ground) No 20 83.2 230 0
Tractor No 40 84 230 0
Dozer No 40 81.7 230 0
Dump Truck No 40 76.5 230 0
Excavator No 40 80.7 230 0
Grader No 40 85 230 0
Front End Loader No 40 79.1 230 0
All Other Equipment > 5 HPNo 50 85 230 0
Results
Calculated (dBA) Noise Limits (dBA)
Day Evening Night
Equipment *Lmax Leq Lmax Leq Lmax Leq Lmax
Backhoe 64.3 60.3 N/A N/A N/A N/A N/A
Compactor (ground) 70 63 N/A N/A N/A N/A N/A
Tractor 70.7 66.8 N/A N/A N/A N/A N/A
Dozer 68.4 64.4 N/A N/A N/A N/A N/A
Dump Truck 63.2 59.2 N/A N/A N/A N/A N/A
Excavator 67.5 63.5 N/A N/A N/A N/A N/A
Grader 71.7 67.8 N/A N/A N/A N/A N/A
Front End Loader 65.9 61.9 N/A N/A N/A N/A N/A
All Other Equipment > 5 HP 71.7 68.7 N/A N/A N/A N/A N/A Total 71.7 74.6 N/A N/A N/A N/A N/A
*Calculated Lmax is the Loudest value.
---- Receptor #2 ----
Baselines (dBA)
DescriptionLand Use Daytime Evening Night
Single Family - WestResidential 65 60 55
Equipment
Spec Actual Receptor Estimated
ITEM 13
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with Appendices

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Impact Lmax Lmax Distance Shielding
Description Device Usage(%) (dBA) (dBA) (feet) (dBA)
Backhoe No 40 77.6 250 0
Compactor (ground) No 20 83.2 250 0
Tractor No 40 84 250 0
Dozer No 40 81.7 250 0
Dump Truck No 40 76.5 250 0
Excavator No 40 80.7 250 0
Grader No 40 85 250 0
Front End Loader No 40 79.1 250 0
All Other Equipment > 5 HPNo 50 85 250 0
Results
Calculated (dBA) Noise Limits (dBA)
Day Evening Night
Equipment *Lmax Leq Lmax Leq Lmax Leq Lmax
Backhoe 63.6 59.6 N/A N/A N/A N/A N/A
Compactor (ground) 69.3 62.3 N/A N/A N/A N/A N/A
Tractor 70 66 N/A N/A N/A N/A N/A
Dozer 67.7 63.7 N/A N/A N/A N/A N/A
Dump Truck 62.5 58.5 N/A N/A N/A N/A N/A
Excavator 66.7 62.8 N/A N/A N/A N/A N/A
Grader 71 67 N/A N/A N/A N/A N/A
Front End Loader 65.1 61.2 N/A N/A N/A N/A N/A
All Other Equipment > 5 HP 71 68 N/A N/A N/A N/A N/A
Total 71 73.8 N/A N/A N/A N/A N/A
*Calculated Lmax is the Loudest value.

ITEM 13
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with Appendices

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Noise Limit Exceedance (dBA)
Day Evening Night
Leq Lmax Leq Lmax Leq Lmax Leq

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A
ITEM 13
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with Appendices

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Noise Limit Exceedance (dBA)
Day Evening Night
Leq Lmax Leq Lmax Leq Lmax Leq

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A
ITEM 13
Attachment E 575 Los Trancos Road
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with Appendices

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Roadway Construction Noise Model (RCNM),Version 1.1
Report date:########
Case Description:575 Los Trancos Road - Grading
---- Receptor #1 ----
Baselines (dBA)
DescriptionLand Use Daytime Evening Night
Single Family - NorthResidential 65 60 55
Equipment
Spec Actual Receptor Estimated
Impact Lmax Lmax Distance Shielding
Description Device Usage(%) (dBA) (dBA) (feet) (dBA)
Backhoe No 40 77.6 230 0
Compactor (ground) No 20 83.2 230 0
Dozer No 40 81.7 230 0
Excavator No 40 80.7 230 0
Grader No 40 85 230 0
Front End Loader No 40 79.1 230 0
All Other Equipment > 5 HPNo 50 85 230 0
Results
Calculated (dBA) Noise Limits (dBA)
Day Evening Night
Equipment *Lmax Leq Lmax Leq Lmax Leq Lmax
Backhoe 64.3 60.3 N/A N/A N/A N/A N/A
Compactor (ground) 70 63 N/A N/A N/A N/A N/A
Dozer 68.4 64.4 N/A N/A N/A N/A N/A
Excavator 67.5 63.5 N/A N/A N/A N/A N/A
Grader 71.7 67.8 N/A N/A N/A N/A N/A
Front End Loader 65.9 61.9 N/A N/A N/A N/A N/A
All Other Equipment > 5 HP 71.7 68.7 N/A N/A N/A N/A N/A Total 71.7 73.6 N/A N/A N/A N/A N/A
*Calculated Lmax is the Loudest value.
---- Receptor #2 ----
Baselines (dBA)
DescriptionLand Use Daytime Evening Night
Single Family - WestResidential 65 60 55
Equipment
Spec Actual Receptor Estimated
Impact Lmax Lmax Distance Shielding
Description Device Usage(%) (dBA) (dBA) (feet) (dBA)
Backhoe No 40 77.6 250 0
Compactor (ground) No 20 83.2 250 0
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
262
Packet Page 692 of 792

Dozer No 40 81.7 250 0
Excavator No 40 80.7 250 0
Grader No 40 85 250 0
Front End Loader No 40 79.1 250 0
All Other Equipment > 5 HPNo 50 85 250 0
Results
Calculated (dBA) Noise Limits (dBA)
Day Evening Night
Equipment *Lmax Leq Lmax Leq Lmax Leq Lmax
Backhoe 63.6 59.6 N/A N/A N/A N/A N/A
Compactor (ground) 69.3 62.3 N/A N/A N/A N/A N/A
Dozer 67.7 63.7 N/A N/A N/A N/A N/A
Excavator 66.7 62.8 N/A N/A N/A N/A N/A
Grader 71 67 N/A N/A N/A N/A N/A
Front End Loader 65.1 61.2 N/A N/A N/A N/A N/A
All Other Equipment > 5 HP 71 68 N/A N/A N/A N/A N/A
Total 71 72.9 N/A N/A N/A N/A N/A
*Calculated Lmax is the Loudest value.

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
263
Packet Page 693 of 792

Noise Limit Exceedance (dBA)
Day Evening Night
Leq Lmax Leq Lmax Leq Lmax Leq

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
264
Packet Page 694 of 792

Noise Limit Exceedance (dBA)
Day Evening Night
Leq Lmax Leq Lmax Leq Lmax Leq

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
265
Packet Page 695 of 792

Roadway Construction Noise Model (RCNM),Version 1.1
Report date:########
Case Description:575 Los Trancos Road - Building Construction ---- Receptor #1 ----
Baselines (dBA)
DescriptionLand Use Daytime Evening Night
Single Family - NorthResidential 65 60 55
Equipment
Spec Actual Receptor Estimated
Impact Lmax Lmax Distance Shielding
Description Device Usage(%) (dBA) (dBA) (feet) (dBA)
Man Lift No 20 74.7 230 0
Concrete Mixer Truck No 40 78.8 230 0
Concrete Saw No 20 89.6 230 0
Compactor (ground) No 20 83.2 230 0
Compressor (air) No 40 77.7 230 0
Crane No 16 80.6 230 0
Dump Truck No 40 76.5 230 0
Generator No 50 80.6 230 0
Pumps No 50 80.9 230 0
All Other Equipment > 5 HPNo 50 85 230 0
Results
Calculated (dBA) Noise Limits (dBA)
Day Evening Night
Equipment *Lmax Leq Lmax Leq Lmax Leq Lmax
Man Lift 61.4 54.5 N/A N/A N/A N/A N/A
Concrete Mixer Truck 65.5 61.6 N/A N/A N/A N/A N/A
Concrete Saw 76.3 69.3 N/A N/A N/A N/A N/A
Compactor (ground) 70 63 N/A N/A N/A N/A N/A
Compressor (air) 64.4 60.4 N/A N/A N/A N/A N/A
Crane 67.3 59.3 N/A N/A N/A N/A N/A
Dump Truck 63.2 59.2 N/A N/A N/A N/A N/A
Generator 67.4 64.4 N/A N/A N/A N/A N/A
Pumps 67.7 64.7 N/A N/A N/A N/A N/A
All Other Equipment > 5 HP 71.7 68.7 N/A N/A N/A N/A N/A Total 76.3 74.5 N/A N/A N/A N/A N/A
*Calculated Lmax is the Loudest value.
---- Receptor #2 ----
Baselines (dBA)
DescriptionLand Use Daytime Evening Night
Single Family - WestResidential 65 60 55
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
266
Packet Page 696 of 792

Equipment
Spec Actual Receptor Estimated
Impact Lmax Lmax Distance Shielding
Description Device Usage(%) (dBA) (dBA) (feet) (dBA)
Man Lift No 20 74.7 250 0
Concrete Mixer Truck No 40 78.8 250 0
Concrete Saw No 20 89.6 250 0
Compactor (ground) No 20 83.2 250 0
Compressor (air) No 40 77.7 250 0
Crane No 16 80.6 250 0
Dump Truck No 40 76.5 250 0
Generator No 50 80.6 250 0
Pumps No 50 80.9 250 0
All Other Equipment > 5 HPNo 50 85 250 0
Results
Calculated (dBA) Noise Limits (dBA)
Day Evening Night
Equipment *Lmax Leq Lmax Leq Lmax Leq Lmax
Man Lift 60.7 53.7 N/A N/A N/A N/A N/A
Concrete Mixer Truck 64.8 60.8 N/A N/A N/A N/A N/A
Concrete Saw 75.6 68.6 N/A N/A N/A N/A N/A
Compactor (ground) 69.3 62.3 N/A N/A N/A N/A N/A
Compressor (air) 63.7 59.7 N/A N/A N/A N/A N/A
Crane 66.6 58.6 N/A N/A N/A N/A N/A
Dump Truck 62.5 58.5 N/A N/A N/A N/A N/A
Generator 66.7 63.6 N/A N/A N/A N/A N/A
Pumps 67 64 N/A N/A N/A N/A N/A
All Other Equipment > 5 HP 71 68 N/A N/A N/A N/A N/A
Total 75.6 73.8 N/A N/A N/A N/A N/A
*Calculated Lmax is the Loudest value.

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
267
Packet Page 697 of 792

Noise Limit Exceedance (dBA)
Day Evening Night
Leq Lmax Leq Lmax Leq Lmax Leq

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
268
Packet Page 698 of 792

Noise Limit Exceedance (dBA)
Day Evening Night
Leq Lmax Leq Lmax Leq Lmax Leq

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
269
Packet Page 699 of 792

Roadway Construction Noise Model (RCNM),Version 1.1
Report date:########
Case Description:575 Los Trancos Road - Paving
---- Receptor #1 ----
Baselines (dBA)
DescriptionLand Use Daytime Evening Night
Single Family - NorthResidential 65 60 55
Equipment
Spec Actual Receptor Estimated
Impact Lmax Lmax Distance Shielding
Description Device Usage(%) (dBA) (dBA) (feet) (dBA)
Backhoe No 40 77.6 230 0
Concrete Saw No 20 89.6 230 0
Compactor (ground) No 20 83.2 230 0
Tractor No 40 84 230 0
Grader No 40 85 230 0
Front End Loader No 40 79.1 230 0
Paver No 50 77.2 230 0
Roller No 20 80 230 0
All Other Equipment > 5 HPNo 50 85 230 0
Results
Calculated (dBA) Noise Limits (dBA)
Day Evening Night
Equipment *Lmax Leq Lmax Leq Lmax Leq Lmax
Backhoe 64.3 60.3 N/A N/A N/A N/A N/A
Concrete Saw 76.3 69.3 N/A N/A N/A N/A N/A
Compactor (ground) 70 63 N/A N/A N/A N/A N/A
Tractor 70.7 66.8 N/A N/A N/A N/A N/A
Grader 71.7 67.8 N/A N/A N/A N/A N/A
Front End Loader 65.9 61.9 N/A N/A N/A N/A N/A
Paver 64 61 N/A N/A N/A N/A N/A
Roller 66.7 59.8 N/A N/A N/A N/A N/A
All Other Equipment > 5 HP 71.7 68.7 N/A N/A N/A N/A N/A Total 76.3 75.3 N/A N/A N/A N/A N/A
*Calculated Lmax is the Loudest value.
---- Receptor #2 ----
Baselines (dBA)
DescriptionLand Use Daytime Evening Night
Single Family - WestResidential 65 60 55
Equipment
Spec Actual Receptor Estimated
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
270
Packet Page 700 of 792

Impact Lmax Lmax Distance Shielding
Description Device Usage(%) (dBA) (dBA) (feet) (dBA)
Backhoe No 40 77.6 250 0
Concrete Saw No 20 89.6 250 0
Compactor (ground) No 20 83.2 250 0
Tractor No 40 84 250 0
Grader No 40 85 250 0
Front End Loader No 40 79.1 250 0
Paver No 50 77.2 250 0
Roller No 20 80 250 0
All Other Equipment > 5 HPNo 50 85 250 0
Results
Calculated (dBA) Noise Limits (dBA)
Day Evening Night
Equipment *Lmax Leq Lmax Leq Lmax Leq Lmax
Backhoe 63.6 59.6 N/A N/A N/A N/A N/A
Concrete Saw 75.6 68.6 N/A N/A N/A N/A N/A
Compactor (ground) 69.3 62.3 N/A N/A N/A N/A N/A
Tractor 70 66 N/A N/A N/A N/A N/A
Grader 71 67 N/A N/A N/A N/A N/A
Front End Loader 65.1 61.2 N/A N/A N/A N/A N/A
Paver 63.2 60.2 N/A N/A N/A N/A N/A
Roller 66 59 N/A N/A N/A N/A N/A
All Other Equipment > 5 HP 71 68 N/A N/A N/A N/A N/A
Total 75.6 74.5 N/A N/A N/A N/A N/A
*Calculated Lmax is the Loudest value.

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
271
Packet Page 701 of 792

Noise Limit Exceedance (dBA)
Day Evening Night
Leq Lmax Leq Lmax Leq Lmax Leq

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
272
Packet Page 702 of 792

Noise Limit Exceedance (dBA)
Day Evening Night
Leq Lmax Leq Lmax Leq Lmax Leq

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
273
Packet Page 703 of 792

Roadway Construction Noise Model (RCNM),Version 1.1
Report date:########
Case Description:575 Los Trancos Road - Architectural Coating ---- Receptor #1 ----
Baselines (dBA)
DescriptionLand Use Daytime Evening Night
Single Family - NorthResidential 65 60 55
Equipment
Spec Actual Receptor Estimated
Impact Lmax Lmax Distance Shielding
Description Device Usage(%) (dBA) (dBA) (feet) (dBA)
Compressor (air) No 40 77.7 230 0
Results
Calculated (dBA) Noise Limits (dBA)
Day Evening Night
Equipment *Lmax Leq Lmax Leq Lmax Leq Lmax
Compressor (air) 64.4 60.4 N/A N/A N/A N/A N/A
Total 64.4 60.4 N/A N/A N/A N/A N/A
*Calculated Lmax is the Loudest value.
---- Receptor #2 ----
Baselines (dBA)
DescriptionLand Use Daytime Evening Night
Single Family - WestResidential 65 60 55
Equipment
Spec Actual Receptor Estimated
Impact Lmax Lmax Distance Shielding
Description Device Usage(%) (dBA) (dBA) (feet) (dBA)
Compressor (air) No 40 77.7 250 0
Results
Calculated (dBA) Noise Limits (dBA)
Day Evening Night
Equipment *Lmax Leq Lmax Leq Lmax Leq Lmax
Compressor (air) 63.7 59.7 N/A N/A N/A N/A N/A
Total 63.7 59.7 N/A N/A N/A N/A N/A
*Calculated Lmax is the Loudest value.

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
274
Packet Page 704 of 792

Noise Limit Exceedance (dBA)
Day Evening Night
Leq Lmax Leq Lmax Leq Lmax Leq

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A
Noise Limit Exceedance (dBA)
Day Evening Night
Leq Lmax Leq Lmax Leq Lmax Leq

N/A N/A N/A N/A N/A N/A N/A

N/A N/A N/A N/A N/A N/A N/A
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
275
Packet Page 705 of 792

0.21 94 0.050 25

0.089 87 0.022 25

0.089 87 0.022 25

0.089 87 0.022 25

0.076 83 0.014 25

0.035 79 0.009 25

0.003 58 0.001 25
35 0.1450 91 0.035
35 0.0615 84 0.015
35 0.0615 84 0.015
35 0.0615 84 0.015
35 0.0525 80 0.010
35 0.0242 76 0.006
35 0.0021 55 0.001

0.200 PPV 72.0 VdB 0.0080 RMS
26 250 133
12 120 64
12 120 64
12 120 64
10 79 42
5 52 28
1 6 3
Last Updated: 4/11/2019
The reference distance is measured from the nearest anticipated point of construction equipment to the nearest structure.

Small bulldozer
Reference Level Inputs
Equipment
PPVref
(in/sec)
Lvref
(VdB)
RMSref
(in/sec)
Reference
Distance
Vibratory Roller
Hoe Ram
Hoe Ram
Large bulldozer
Caisson drilling
Loaded trucks
Jack hammer
Caisson drilling
Loaded trucks
Distance
(feet)
PPVx
(in/sec) Equipment
Lvx
(VdB)
RMSx
(in/sec)
Vibratory Roller
Hoe Ram
Large bulldozer
Notes
Groundborne Noise and Vibration Modeling
Source
California Department of Transportation (Caltrans). 2013. Transportation and Construction Vibratory Roller
Vibration Level at Receiver
Jack hammer
Small bulldozer
Large bulldozer
Caisson drilling
Loaded trucks
Jack hammer
Small bulldozer
Vibration Contours
Equipment
Distance to (feet)
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
276
Packet Page 706 of 792

0.21 94 0.050 25

0.089 87 0.022 25

0.089 87 0.022 25

0.089 87 0.022 25

0.076 83 0.014 25

0.035 79 0.009 25

0.003 58 0.001 25
50 0.0980 87 0.023
50 0.0415 80 0.010
50 0.0415 80 0.010
50 0.0415 80 0.010
50 0.0355 76 0.007
50 0.0163 72 0.004
50 0.0014 51 0.000

0.200 PPV 72.0 VdB 0.0080 RMS
26 250 133
12 120 64
12 120 64
12 120 64
10 79 42
5 52 28
1 6 3
Last Updated: 4/11/2019
The reference distance is measured from the nearest anticipated point of construction equipment to the nearest structure.

Small bulldozer
Reference Level Inputs
Equipment
PPVref
(in/sec)
Lvref
(VdB)
RMSref
(in/sec)
Reference
Distance
Vibratory Roller
Hoe Ram
Hoe Ram
Large bulldozer
Caisson drilling
Loaded trucks
Jack hammer
Caisson drilling
Loaded trucks
Distance
(feet)
PPVx
(in/sec) Equipment
Lvx
(VdB)
RMSx
(in/sec)
Vibratory Roller
Hoe Ram
Large bulldozer
Notes
Groundborne Noise and Vibration Modeling
Source
California Department of Transportation (Caltrans). 2013. Transportation and Construction Vibratory Roller
Vibration Level at Receiver
Jack hammer
Small bulldozer
Large bulldozer
Caisson drilling
Loaded trucks
Jack hammer
Small bulldozer
Vibration Contours
Equipment
Distance to (feet)
ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
277
Packet Page 707 of 792

Appendix E
California Water Service and West Bay Sanitary District Will Serve Letter ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
278
Packet Page 708 of 792

&nbsp;
ITEM 13
Attachment E 575 Los Trancos Road Residential Project Final IS-MND with Appendices &nbsp;
&nbsp;
&nbsp;
Item&nbsp; 13:&nbsp;Page&nbsp;279
Packet Page 709 of 792&nbsp;

WEST BAY SANITARY DISTRICT
500 Laurel Street, Menlo Park, CA 94025
Telephone: (650) 321-0384 Fax (650) 321 -4265

WILL SERVE LETTER
APN : 182-46-012
August 17, 2021

City of Palo Alto Building Department
285 Hamilton Ave # 1
Palo Alto, CA 94301

RE: 575 LOS TRANCOS RD

SANTA CLARA COUNTY
PROPERTY OWNER :

APN : 182-46-012

Dear City of Palo Alto Building Department:

This letter will serve as notice that the above-referenced address is within the West Bay Sanitary District’s jurisdiction, and is entitled to receive all available services from the District, pursuant to compliance with the District’s Code of General Regulations.

Should you have any questions please feel free to call the administration office at the District at (650) 321-0384. The property owners or their contractor may also feel free to contact our administration office with any questions.

Very truly yours,

WEST BAY SANITARY DISTRICT

Todd Reese
Office Manager

ITEM 13
Attachment E 575 Los Trancos Road
Residential Project Final IS-MND
with Appendices

Item 13:

Page
280
Packet Page 710 of 792

&nbsp;
ITEM 13
Attachment E 575 Los Trancos Road Residential Project Final IS-MND with Appendices &nbsp;
&nbsp;
&nbsp;
Item&nbsp; 13:&nbsp;Page&nbsp;281
Packet Page 711 of 792&nbsp;

MITIGATION MONITORING + REPORTING PROGRAM
City of Palo Alto  Mitigation Monitoring + Reporting Program Page | 1

PROJECT NAME 575 Los Trancos Road Residential
Project

APPLICATION
NUMBER
21PLN-00196
APPROVED BY Emily Foley, City of Palo Alto
APPLICANT/OWNER Innovative Homes LLC
John Suppes
412 Olive Avenue, Palo Alto, CA 94306
[email protected]

The Final Initial Study Mitigated Negative Declaration (IS-MND) for the 575 Los Trancos Road Residential Project identifies the mitigation measures that must be implemented to reduce the impacts associated with the project. The California Environmental Quality Act (CEQA) was amended in 1989 to add Section 21081.6, which requires a public agency to adopt a monitoring and reporting program for assessing and ensuring compliance with any required mitigation measures applied to proposed development. As stated in section 21081.6(a)(1) of the Public Resources Code:
... the public agency shall adopt a reporting or monitoring program for the changes made to the project or conditions of project approval, adopted in order to mitigate or avoid significant effects on the environment.

Section 21081.6 also provides general guidelines for implementing mitigation monitoring programs and indicates that specific reporting and/or monitoring requirements, to be enforced during project implementation, shall be defined as part of adopting an IS-MND.

The mitigation monitoring table lists those mitigation measures that would be included as conditions of approval for the project. To ensure that the mitigation measures are properly implemented, a monitoring program has been devised which identifies the timing and responsibility for monitoring each measure.

ITEM 13
Attachment F 575 Los Trancos
MMRP

Item 13:

Page
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MITIGATION MONITORING + REPORTING PROGRAM
City of Palo Alto  Mitigation Monitoring + Reporting Program Page | 2

Environmental
Impact Mitigation Measure Responsible for
Implementation
Timing of
Compliance
Oversight of
Implementation

AIR QUALITY
AQ-1 BAAQMD Basic Construction Mitigation. The property owner or their designee shall implement the following
measures during project construction to reduce dust fall- out emissions:
 All exposed surfaces (e.g., parking areas, staging
areas, soil piles, and graded areas) shall be watered
two times per day.
 All haul trucks transporting soil, sand, or other loose material off-site shall be covered or maintain at least 2 feet of freeboard.
 All visible mud or dirt track-out onto adjacent public roads shall be removed using wet power vacuum
street sweepers at least once per day. The use of dry
power sweeping is prohibited.
 Enclose, cover, water daily or apply non-toxic soil
binders to exposed stockpiles (dirt, sand, etc.)
 All roadways, driveways, and sidewalks to be paved
shall be completed as soon as possible. Building pads
shall be laid as soon as possible after grading unless
seeding or soil binders are used.
 Install sandbags or other erosion control measures
to prevent silt runoff to public roadways.
 Idling times shall be minimized either by shutting
equipment off when not in use or reducing the
maximum idling time to 5 minutes (as required by
the California airborne toxics control measure CCR
Title 13, Section 2485). Clear signage shall be
Project
Applicant/verified
in the field by the
Development
Services
Department
Building Division
Prior to issuance
of grading
permit and
periodically
during
construction
City of Palo Alto
Development
Services
Department
Building Division
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provided for construction workers at all access
points.
 All construction equipment shall be maintained and
properly tuned in accordance with manufacturer’s
specifications. All equipment shall be checked by a
certified visible emissions evaluator.
 Post a publicly visible sign with the telephone
number and person to contact at the City of Palo
Alto or construction contractor regarding dust
complaints. This person shall respond and take
corrective action within 48 hours. The air district’s
phone number shall also be visible to ensure
compliance with applicable regulations.

BIOLOGICAL RESOURCES
BIO-1 Worker Environmental Awareness Program (WEAP).

Prior to initiation of construction activities (including staging and mobilization) all personnel associated with project construction shall attend a Worker
Environmental Awareness Program (WEAP) training,
conducted by a qualified biologist, to aid workers in
recognizing special-status resources that may occur in
the construction area. The specifics of this program shall include identification of the sensitive species and
habitats, a description of the regulatory status and
general ecological characteristics of sensitive resources, and review of the limits of construction and measures
required to reduce impacts to biological resources within the work area. A qualified biologist shall prepare a fact sheet conveying this information for distribution to all contractors, their employers, and other personnel
involved with construction. All employees shall sign a
form provided by the trainer indicating they have
attended the WEAP and understand the information
presented to them. The forms from all trainings shall be available to the City upon request to document
compliance.

Project Applicant/
verified in the
field by the
Development
Services
Department
Building Division
Prior to
initiation of
construction
activities
City of Palo Alto
Development
Services
Department
Building Division
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BIO-2 Special-Status Plant Species Botanical Surveys. A qualified biologist shall conduct a protocol level botanical survey, including a site visit during the blooming period of the target species in March through July. If the CRPR 1 rank plant is found, the plants shall be avoided by
installing protective fencing and warning construction
personnel of their presence through the WEAP training.

If special-status plants species cannot be avoided,
impacts shall be mitigated at a minimum ratio of 1:1
(number of acres or individuals restored to number of
acres or individuals impacted). A restoration plan shall be prepared and submitted to the City for review and
approval and to CDFW for review. The restoration plan
shall include, at a minimum, the type and area of habitat to be established, restored, enhanced, and/or preserved; goals and objectives of the mitigation project; a
monitoring plan including performance standards and
success criteria; and maintenance activities to occur
during monitoring. The applicant shall implement the
measures prior to commencement of ground
disturbance, tree removal or construction.

Project Applicant/
verified by the
Development
Services
Department
Building Division
Prior to
initiation of
construction
activities; during
restoration if
required
City of Palo Alto
Development
Services
Department
BIO-3 Best Management Practices for Protection of Steelhead and Aquatic Habitat. No vegetation removal, ground
disturbance or construction shall occur within the creek or the 20-foot creek setback zone, which shall be
demarcated with high visibility orange construction
fencing to ensure avoidance of impacts to the aquatic
habitat. Best management practices (BMPs) shall be
developed and implemented during all grading and
construction activities to prevent erosion and
sedimentation into the creek and to prevent the spill of contaminants in or around the creek. The following BMPs shall be included and implemented on-site during
construction to prevent any indirect impacts to aquatic habitat, as well as jurisdictional waters and wetlands:
 Vehicles and equipment shall be checked at least
daily for leaks and maintained in good working
Project Applicant/
verified in the
field by the
Development
Services
Department
Building Division
Prior to
initiation of
construction
activities and
periodically
during
construction
City of Palo Alto
Development
Services
Department
Building Division
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order. Spill kits shall be available on-site at all times and a spill response plan shall be developed and
implemented.
 Sediment and erosion control measures (e.g., sand
or gravel bags, hay bales, check dams) shall be
implemented and maintained throughout the
project site to prevent the entry of sediment and/or
pollutants into any waterways or jurisdictional areas.

No monofilament plastic may be used for erosion
control materials.

BIO-4 Preconstruction Surveys for California Giant
Salamander, Santa Cruz Black Salamander, Western
Pond Turtle, California Red-Legged Frog, and San
Francisco Garter Snake. A qualified biologist shall
conduct a pre-construction survey within 24 hours of the initiation of project activities. If California Giant
Salamander, Santa Cruz Black Salamander, and/or
Western Pond Turtle are observed the animal shall be
allowed to leave the site on its own. If California Red- Legged Frog, and/or San Francisco garter snake is found, USFWS shall be notified immediately to determine the
correct course of action and the proposed project shall not begin until approved by USFWS.

Prior to ground disturbance, a temporary wildlife
exclusion barrier shall be installed along the limits of disturbance. A qualified biologist shall inspect the area prior to barrier installation. The barrier shall be designed to prevent the target species from entering the project area and will remain in place until all development
activities have been completed. This barrier shall be
inspected daily by a qualified biologist and maintained and repaired as necessary to ensure that it is functional and is not a hazard to the target species on the outer
side of the barrier.

A qualified biologist shall be present during all grading and initial ground disturbing activities. Vegetation
disturbance shall be the minimum necessary to achieve
Project Applicant/
verified by the
Development
Services
Department
Prior to
initiation of
construction
activities; during
grading and
initial ground
disturbing
activities; during
construction if
required
City of Palo Alto
Development
Services
Department
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the goals of the project. Immediately prior to initial
ground disturbance and vegetation removal, a qualified
biologist shall conduct a visual clearance survey.

Vegetation shall be cut to 6 inches in height using hand tools (including string trimmers or chainsaw for brush).

Once the ground is visible, a second visual survey for
target species shall be conducted by the biologist prior to additional ground disturbance.

Should California Giant Salamander, Santa Cruz Black
Salamander, or Western Pond Turtle be observed within
the project site, construction shall be halted in the
vicinity until either the animal exits the site on its own or until a qualified biologist relocates the animal to suitable habitat in the immediate vicinity. Should California Red- Legged Frog, and/or San Francisco garter snake be
observed within the project site, the USFWS shall be
notified immediately and construction shall be halted
until either the animal exits the site on its own or until a qualified biologist with the appropriate USFWS Recovery Permit relocates the animal.

No work shall occur during a rain event over 0.25.” If a rain event occurs, a qualified biologist shall inspect the site again prior to resuming work. All holes and trenches shall be covered at the end of the day or ramped to avoid entrapment
BIO-5
Focused Surveys for Special-Status Bat Species and
Roosting Bat Protection Plan. Prior to tree removal, a
qualified biologist shall conduct a focused survey of all trees to be removed or impacted by construction
activities to determine whether active roosts of special- status bats are present on site. If tree removal is planned for the fall, it is recommended the survey be conducted in September to ensure tree removal would have
adequate time to occur during seasonal periods of bat
activity, as described below. If tree removal is planned for the spring, it is recommended the survey be
conducted during the earliest possible time in March, to Project Applicant/
verified by the
Development
Services
Department
Prior to tree
removal and
during tree
removal if bats
found
City of Palo Alto
Development
Services
Department
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allow for suitable conditions for both the detection of bats and subsequent tree removal. Trees containing
suitable potential bat roost habitat features shall be
clearly marked or identified.

If day roosts are found to be potentially present, the
biologist shall prepare a site-specific roosting bat
protection plan to be implemented by the contractor
following the City of Palo Alto’s approval. The plan shall incorporate the following guidance as appropriate:
 To the extent possible, trees identified as suitable
roosting habitat shall be removed during seasonal
periods of bat activity, including the following, but
not during maternity season:
o Between September 1 and about October
15, or before evening temperatures fall
below 45 degrees Fahrenheit and/or more
than 0.5 inch of rainfall within 24 hours
occurs.
o Between March 1 and April 15, or after
evening temperatures rise above 45
degrees Fahrenheit and/or no more than

0.5 inch of rainfall within 24 hours occurs.
 If a tree must be removed during the
maternity/breeding season and is identified as
potentially containing a colonial maternity roost,
then a qualified biologist shall conduct acoustic
emergence surveys or implement other appropriate
methods to further evaluate if the roost is an active
maternity roost. Under the biologist’s guidance, the
contractor shall implement measures similar to or
better than the following:
o If it is determined that the roost is not an
active maternity roost, then the roost may
be removed in accordance with the other
requirements of this recommendation.
o If it is found that an active maternity roost
of a colonial roosting species is present, the
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roost shall not be disturbed during the
breeding season (April 15 to August 31).
 Potential colonial hibernation roosts may only be
removed during seasonal periods of bat activity.

Potential non-colonial roosts that cannot be avoided
shall be removed on warm days in late morning to
afternoon when any bats present are likely to be
warm and able to fly. Appropriate methods shall be
used to minimize the potential harm to bats during
tree removal. Such methods may include using a
two-step tree removal process. This method is
conducted over two consecutive days and works by
creating noise and vibration by cutting non-habitat
branches and limbs from habitat trees using
chainsaws only (no excavators or other heavy
machinery) on day one. The noise and vibration
disturbance, together with the visible alteration of
the tree, is very effective in causing bats that emerge nightly to feed to not return to the roost that night.

The remainder of the tree is removed on day two.

BIO-6 Preconstruction Surveys for San Francisco Dusky-Footed Woodrat. A qualified biologist shall conduct a pre-
construction survey for woodrats no more than 14 days
prior to construction. Nests within 50 feet of project
activity that would not be directly impacted by project activity shall be demarcated with a 10-foot avoidance
buffer and left intact. If a nest(s) that cannot be avoided are found during the pre-construction survey, an
approved biologist shall dismantle the nest and relocate it to suitable habitat outside the work area no more than 50 feet away with the goal of ensuring the individuals are allowed to leave the work area(s) unharmed before on
site activities begin. Nest relocation shall occur within 48 hours of construction activities to ensure that nests are not reestablished.

Project Applicant/
verified by the
Development
Services
Department
No more than
14 days prior to
initiation of
construction
activities
City of Palo Alto
Development
Services
Department
BIO-7
Preconstruction Surveys for Nesting Birds. A general
pre-construction nesting bird survey shall be conducted Project Applicant/
verified by the
Within 14 days
prior to the
City of Palo Alto
Development
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by a qualified biologist within 14 days prior to the
initiation of construction activities. If construction is stopped for more than 14 days during the nesting
season, a pre-construction survey shall be conducted
prior to the re-start of construction activities. Surveys shall include the disturbance area plus a 50-foot buffer for passerine species, and a 500-foot buffer for raptors.

If active nests are located, an appropriate avoidance
buffer shall be established within which no work activity would be allowed that would impact these nests. The
avoidance buffer shall be established by the qualified
biologist on a case-by-case basis based on the species
and site conditions. Larger buffers may be required
depending upon the status of the nest and the
construction activities occurring in the vicinity of the nest. The buffer area(s) shall be closed to all construction personnel and equipment until juveniles have fledged
and/or the nest is inactive. A qualified biologist shall confirm that breeding/nesting is complete, and the nest is no longer active prior to removal of the buffer. If work within a buffer area cannot be avoided, then a qualified biologist shall be present to monitor all project activities that occur within the buffer. The biological monitor shall evaluate the nesting avian species for signs of
disturbance and shall have the ability to stop work.

Development
Services
Department
initiation of
construction
activities
Services
Department
BIO-8 Protection of Retained Trees. The project applicant shall adhere to recommendations as described in the arborist
report prepared by Kielty Arborist Services (Kielty
Arborist Services 2021) regarding protection of retained trees. Recommendations include landscape buffers, tree
pruning, root cutting, trenching and excavation,
irrigation, grading, and inspections.

Project Applicant/
verified by the
Development
Services
Department
Prior to issuance
of grading
permit and
during site
preparation
City of Palo Alto
Development
Services
Department

CULTURAL RESOURCES
CR-1 Worker’s Environmental Awareness Program (WEAP).

Prior to project ground disturbance, all construction
personnel and contractors responsible for overseeing
and operating ground-disturbing activities shall be
Project Applicant/
verified by the
Development
Prior to ground
disturbance
City of Palo Alto
Development
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required to receive cultural awareness and sensitivity
training. The purpose of this training is to educate
construction personnel regarding the legal obligations of the project, the types of archaeological deposits that
may be encountered during construction, and the
appropriate procedures required in the event of a
discovery of archaeological resources, paleontological
resources, or human remains. The WEAP shall also
provide cultural sensitivity training to ensure respectful and appropriate behaviors in the vicinity of
archaeological deposits and human remains. The WEAP
shall be implemented by a qualified archaeologist that
meets or exceeds the Secretary of the Interior’s
Professional Qualifications Standards in archaeology.

Services
Department
Services
Department
CR-2 Archaeological and Native American Monitoring. A
qualified archaeologist shall conduct archaeological
monitoring for all project-related ground disturbing
activities. Archaeological monitoring shall be performed under the direction of an archaeologist meeting the
Secretary of the Interior’s Professional Qualification
Standards for archaeology (National Park Service 1983).

Locally affiliated Native American tribes shall be given the opportunity to conduct Native American monitoring.

In the event that Native American monitoring occurs, a
locally affiliated tribal member shall monitor all project- related ground disturbing activities. The monitor(s) will have the authority to halt and redirect work should any archaeological resources be identified during monitoring.

If archaeological resources are encountered during
ground-disturbing activities, work in the immediate area must halt and the find evaluated for listing in the CRHR.

Archaeological monitoring may be reduced to spot-
checking or eliminated at the discretion of the monitors, in consultation with the lead agency, as warranted by
conditions such as encountering bedrock, sediments
being excavated are fill, or negative findings during the first 60 percent of rough grading. If monitoring is
reduced to spot-checking, spot-checking shall occur
Project Applicant/
verified by the
Development
Services
Department
During ground
disturbing
activities
City of Palo Alto
Development
Services
Department
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when ground-disturbance moves to a new location
within the project area and when ground disturbance will extend to depths not previously reached (unless those
depths are within bedrock).

CR-3 Unanticipated Discovery of Cultural or Tribal Cultural Resources. In the event that archaeological resources are unexpectedly encountered during ground-disturbing
activities, work in the immediate area shall be halted and an archaeologist meeting the Secretary of the Interior’s Professional Qualifications Standards for archeology
(National Park Service 1983) shall be contacted
immediately to evaluate the find. If the find is Native American in origin, then a Native American
representative shall also be contacted to participate in the evaluation of the find. The qualified archaeologist, and, if applicable, the Native American representative, shall examine the find and make appropriate
recommendations regarding additional work necessary
to evaluate the significance of the find and the
appropriate treatment of the resource. All cultural
resources identified shall be evaluated for CRHR
eligibility and local listing. Additional work may be
necessary to evaluate the resource for inclusion in the CRHR or local listing. Recommendations could include,
but are not limited to, invasive or non-invasive testing, sampling, laboratory analysis, preservation in place, or data recovery. A report of findings documenting any data recovered during monitoring shall be prepared by a
qualified archaeologist and submitted to the Director of Planning. If the discovery is determined to be Native
American in nature, the on-site Native American
monitor, if applicable, shall be consulted to determine the appropriate treatment of the resource. In the event that no Native American monitor is contracted, locally
affiliated Native American tribes shall be invited to
consult regarding the appropriate treatment of any
Native American resources identified during project
construction.

Project Applicant/
verified by the
Development
Services
Department
During ground
disturbing
activities
City of Palo Alto
Development
Services
Department
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GEOLOGY/SOILS
GEO-1 Geotechnical Design Considerations. The project plans submitted for building permit approval shall incorporate the design recommendations outlined in the
Geotechnical Study prepared by Earth Systems on April
9, 2021, or any other design feature or measure shown
to equivalently reduce impacts associated with geology
and soils to the satisfaction of the Director of Public Works. These include recommendations under the
categories of:
 General site preparation
 Compaction
 Fill
 Mat slab foundations
 Post-tensioned slab foundations
 Interior slab-on-grade construction
 Exterior flatwork
 Swimming pool
 Utility trench backfills
 Management of site drainage and finish
improvements
 Geotechnical observation and testing
Refer to the Geotechnical Study for full detail
recommendations for each of the abovementioned
categories.

Project Applicant/
verified by the
Development
Services
Department
Building Division
Prior to issuance
of building
permit
City of Palo Alto
Development
Services
Department
GEO-2
Discovery of Previously Unidentified Paleontological
Resources. In the event a fossil is uncovered during
Project construction, all work shall cease until a certified paleontologist can investigate the finds and make
appropriate recommendations. Any artifacts uncovered
shall be recorded and removed for storage at a location to be determined by the monitor.

Project Applicant/
verified by the
Development
Services
Department
During
construction
activities
City of Palo Alto
Development
Services
Department

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RESPONSES TO CO MMENTS ON THE DRAFT IS-MND
575 Los Trancos Road Residential Project

PREPARED BY
PREPA

RED WITH

THE ASSISTANCE OF
REPO

RT DATE
City of Palo Alto
250 Hamilton Ave nue
Palo Alto, California 94301
C
ontact: Emily Foley, AICP, Associate Planner
Rincon Consultants, Inc.
449 15th Street, Suite 303
Oakland, C alifornia 94612
January 2023
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TABLE OF CONTENTS
CITY OF PALO ALTO Page | i

TABLE OF CONTENTS
RESPONSES TO COMMENTS ON THE DRAFT IS-MND ............................................................................ 1 Letter 1 ............................................................................................................................................. 2 Letter 2 ........................................................................................................................................... 28 Letter 3 ........................................................................................................................................... 43 ITEM 13
Attachment G Responses to
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City of Palo Alto
575 Los Trancos Road Residential Project Responses to Comments on the Draft IS-MND Final Initial Study-Mitigated Negative Declaration

RESPONSES TO COMMENTS ON THE DRAFT IS-MND
This document includes comments received during the circulation of the Draft Initial Study – Mitigated Negative Declaration (IS-MND) prepared for the 575 Los Trancos Road Residential Project (Project).

The Draft IS-MND was circulated for a 30-day public review period that began on August 17, 2022 and ended on September 16, 2022. The City of Palo Alto received three comment letters on the Draft IS-MND. The commenters and the page number on which each commenter’s letter appears are listed below.

Letter No. and Commenter Page No.
1 Jane F. Mark, AICP, Planning Manager, Midp eninsula Regional Open Space District 2 2 Shani
Kleinhaus, Ph.D., Santa Clara Valley Audubon Society, and Gladwyn D’Souza, Sierra Club Loma Prieta Chapter
28 3 Steve Henry 43
1 The comment letters and responses follow. The comment letters have been numbered sequentially and each separate issue raised by the commenter, if more than one, has been assigned a number.

The responses to each comment identify first the number of the comment letter, and then the number assigned to each issue (Response 1.1, for example, indicates that the response is for the first issue raised in comment Letter 1).

In certain instances, the text of the Final IS-MND has been modified in response to comments received or to clarify information. Corrections or additional text are reflected in the text of the Final IS-MND.

In no case did any of the changes made identify new significant impacts or new, avoidable significant effects compared to the impacts identified in the Draft IS-MND. Because none of the revisions to the IS-MND are “substantial” as defined in CEQA Guidelines Section 15073.5(b) and the information added merely clarifies and amplifies the information previously provided in the analysis, recirculation of the IS-MND is not required.

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September 19, 2022

City of Palo Alto Planning and Development Services Department City Hall
250 Hamilton Ave
Palo Alto, CA 94301

SENT VIA E-MAI L TO: [email protected] and [email protected]

Subject: 21PLN-00196, 575 Los Trancos Road (APN 18246012) Draft Initial Study and Mitigated Negative Declaration

Dear Ms. Foley,

On behalf of the Midpeninsula Regional Open Space District (Midpen), we respectfully submit the following comments regarding the Draft Initial Study and Mitigated Negative Declaration (ISMND) for the proposed residential development at 575 Los Trancos Road in the City of Palo Alto. As the owner of an adjacent parcel (APNs 079-080-050, -080, and -090), Midpen appreciates the opportunity to comment on this development and the time extension to submit our agency’s comments to September 19th at 5 pm.

Comprised of over 65,000 acres of acquired and protected open space on the San Francisco Pe
ninsula, Midpen is one of the largest regional open space districts in California. Our mission is to acquire and preserve a regional greenbelt of open space land in perpetuity, protect and restore the natural environment, and provide opportunities for ecologically sensitive public enjoyment and education.

While much of Midpen’s open space lands are along the ridge of the Santa Cruz Mountains, Midpe
n owns and manages Windy Hill Open Space Preserve (Preserve), including the Hawthorns Area, which is located in the Town of Portola Valley and is located within a ¼ mile to the project site. Based on the project’s proximity to the Hawthorns Area, we would like to share specific concerns regarding Biological Resources (BIO) that should be considered as part of the environmental analysis for the ISMND as well as for the design and approval of the project.

Biological Resources
Riparian Habitat
Based on the project plans, it appears the devel opment is adhering to the City’s Stream Corridor Ordinance’s minimum creek setback of 20-ft from Los Trancos Creek. To improve the Letter 1
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clarity of the project plans and environmental review and to show the proposed structure’s proximity to the creek, please provide a figure that includes the proposed building’s footprint as shown on Figure 2 with the creek and property lines as shown on Figure 5.

According to the ISMND, “No vegetation removal, ground disturbance or construction shall oc
cur within the creek or the 20-foot creek setback zone.” Los Trancos Creek supports critical habitat for steelhead, central California coast (CCC) distinct population segment (steelhead) (Oncorhynchus mykiss irideus) and other aquatic species, where building the structure within close proximity to the creek could result in significant impacts to the aquatic species. In addition, the Project may need to modify riparian vegetation that are critical to supporting these aquatic species in order to maintain adequate defensible space for the newly constructed structures (which is usually requested to be 30-100 feet surrounding each structure). As such, the homeowner would need to encroach upon the creek setback area to remove additional vegetation to provide adequate defensible space in the future. This long-term management action would result in the need to remove/trim riparian vegetation. Additional permitting approval would be needed from regulatory agencies who may not be supportive of or approve vegetation modification for these purposes to ensure adequate protection of the creek and associated riparian vegetation. These actions would result in additional impacts on the riparian corridor, steelhead critical habitat and other aquatic species, which the ISMND has not fully analyzed and addressed in the BIO mitigation measures. In addition, please confirm that the City of Palo Alto Fire Department has reviewed the project plans to ensure that adequate defensible space can be provided for the new home and accessory structure located with only a 20-foot setback from the creek without impacting the riparian vegetation.

Wildlife Species and Ha
bitat
The proposed sw imming pool’s placement in close proximity to the creek could result in the entrapment of semiaquatic species such as California Giant Salamander, Santa Cruz Black Salamander, Western Pond Turtle, California Red Legged Frog (CRLF), and San Francisco Garter Snake (SFGS) that may travel across the landscape. These potential additional impacts of entrapment and drowning which could result in the taking of these species should be analyzed and addressed in the BIO mitigation measures with consideration to include wildlife barriers and/or escape ramps installed to prevent entrapment.

The proposed Pro
ject is located in mountain lion habitat and wildlife corridor. The footprint of the new structure appears to be at least a 300-foot long (or greater) north to south barrier to wildlife passage parallel to Los Trancos Creek. This Project could cause wildlife such as deer and mountain lion to circumnavigate the structure in order to travel between open space areas located to the east and west of the proposed project resulting in additional fragmentation of the local habitat. The potential impacts to wildlife movement and fragmentation should be analyzed and addressed in the BIO mitigation measures.

1.1 1.2

1.3 1.4
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Phytophthora / Sudden Oak Death
The area surrounding the proposed project has been heavily impacted by Phy tophthora-caused plant diseases, including Sudden Oak Death (SOD), which was detected within close proximity to the project site in 20191. SOD has been responsible for the death of over one million oak and tanoak trees in California alone. Mortality rates are greater than 50 percent in some areas and continue to increase. Due to the known presence of SOD within the vicinity of the Preserve and the project site, attention is needed to protect the genetic integrity of native oak trees and reduce the potential risk of spreading SOD and related Phytophthora pathogens.

Should the project move forward, Midpen requests that the City incorporate appropriate protocols as part of the Conditions of Approval for the Resource Management Permit to minimize the spread of Phytophthora spp., including disinfecting tools and removing soil from heavy equipment before entering and when leaving the project site. At a minimum, replacement trees should be noninvasive (according to the California Invasive Plant Council), native and ideally native oaks. For replacement oak trees, Midpen requests that the project applicant use acorns sourced from within the watershed rather than nursery stock. Trees grown in nurseries have been known to carry Phytophthora spp. and spread the pathogen where planted. Notably, current research suggests that larger healthy trees in SOD infested areas may carry a genetic resistance to the pathogen. Midpen would be pleased to issue a free permit for acorn collection at Windy Hill, Thornewood, or Teague Hill Open Space Open Space Preserves.

For additional resources, please see the four attached best management practice documents for conducting vegetation work in areas with potential Phytophthora infection.

Midpen did not receive project notification for review of the ISMND, such that we request Jane Mark,
Planning Manager ([email protected]), be added to the City’s future notifications for 575 Los Trancos Road project and other development projects located within the vicinity of the Hawthorns Area of Windy Hill Open Space Preserve. We appreciate the opportunity to comment on this development and the time extension of the public comment period to September 19th at 5 pm. Should you have any questions about this letter, please contact me at (650) 625-6563 or via email.

1 Vollmar Natural Lands Consulting (2019). Botanical Resources Survey Report: Hawthorns Property, Windy Hill Open Space Preserve.

1.5 1.6
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Sincerely,

Jane F. Mark, AICP
Planning Manager

Attachment 1: Guidelines to Minimize Phytophthora Contamination Attachment 2: Midpen Phytophthora Sterilization Guidelines Attachment 3: Sudden Oak Death Precautions and Acorn Planting Protocols Attachment 4: Guidelines to Minimize Phytophthora Pathogens in Restoration Nurseries

CC: Ana Ruiz, General Manager
Susanna Chan, Assistant General Manager

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Working Group for Phytophthoras in Native Habitats October 2016 Guidelines to Minimize Phytophthora Contamination in
Restoration Projects
These guidelines aim to avoid contamination of restoration sites with exotic pathogenic Phytophthora species or other plant pathogens during planting and related activities.

Contents
Definitions ……………………………………………………………………………………………………….…………………… 1 I. Guidelines for General Construction ……………..……………………………………………….…………………. 2 II. Guidelines for Planting at Field Sites ………………………………………………………………….……………… 2 Appendix
A. Procedures for sanitizing tools, surfaces, and footwear…………………………………..………………… 5 B. Clean water specifications ………………………………………………………………………………………………… 6 Definitions:
• Holding facility or nursery: A facility where nursery stock is maintained for a short to extended period of time prior to planting. Plant maintenance activities may include irrigation, fertilization or light pruning, as necessary. Nurseries involved in most other activities, including propagation or repotting are considered production nurseries.
• Job site: The job site includes areas for planting, soil stockpiling, parking, and access roads within and leading to the site.
• Nursery stock: All types of nursery grown plants.
• Planting area: Area being planted for habitat restoration, erosion control, or other purposes. • Planting site: An individual planting basin or other spot, typically no larger than one square yard, where an individual plant or several grouped plants will be installed. • Sanitize: Clean and treat with a sanitizing agent or via a lethal heat exposure to kill plant pathogens present as external contamination.
• Sanitizing agent: Materials such as bleach (sodium hypochlorite solutions), alcohol, quaternary ammonium compounds, and peroxides that can directly kill exposed propagules of Phytophthora or other plant pathogens when used properly. Most sanitizing agents can also kill a wide variety of bacteria and deactivate many viruses. Note that most materials referred to as fungicides are applied to plants to suppress disease but may not kill the pathogens and are not sanitizing agents.
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Working Group for Phytophthoras in Native Habitats October 2016 I. Construction projects
In an effort to minimize the spread of plant pathogens the exterior and interior of all equipment and tools must be clean and free of debris, soil and mud (including tires, treads, wheel wells and undercarriage) prior to arrival at a new job site.

General guidance – suggested standard operating procedures:
a. Vehicles need to stay on established roads unless infeasible. b. In general, vehicles and equipment need to be maintained clean – interior and exterior free of mud, debris and soil especially during the wet season. c. In general, work shoes need to be kept clean- inspect shoe soles and knock mud, debris and soil off treads before moving to a new job site.
d. To minimize the potential for spreading potentially contaminated soil and time required for decontamination, if possible, avoid vehicle traffic and field work when soils are wet enough to stick readily to shoes, tools, equipment and tires.

II. Planting at Field Sites
Overview: Three general routes for the spread of Phytophthora and other soilborne plant pathogens are addressed in these guidelines. These routes are (1) contamination of planting material, including clean nursery stock, and other materials installed at the site, (2) inadvertent introduction of pathogens to a job site from other outside sources (e.g., via contaminated equipment), and (3) potential movement of undetected contamination within the planting area.

These guidelines assume that all nursery stock was originally grown under phytosanitary conditions and tested as remaining free from disease in the nursery (refer to nursery guidelines). These guidelines address how to protect the planting area from subsequent contamination during the delivery, storage onsite, and installation of planting stock and materials.

1. Prevent contamination of clean nursery stock or other clean plant materials Planting stock shall be protected from potential contamination from the point that it leaves the production nursery or collection site until planting. Note that nursery stock has a high risk of infection by Phytophthora species if exposed to these pathogens. Excluding these pathogens provides the only viable option for maintaining outplanted nursery stock free of Phytophthora.

1.1. Maintaining nursery stock in a holding facility
When holding stock for an extended period (after delivery from production nursery and before planting), the following practices need to be followed to prevent contamination of the nursery stock with Phytophthora.

1.1.1. Delivered nursery plants that will be held before planting shall be transferred to cleaned and sanitized raised benches and maintained as described in “Guidelines to Minimize Phytophthora Pathogens for holding (non-production) nurseries at restoration sites, Section

3.”
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1.2. Handl
ing and transporting nursery plants at the job site

1.2.1. Nursery plants shall be transported on or in vehicles or equipment that have been cleaned before loading the stock. Truck beds, racks, or other surfaces need to be swept, blown with compressed air and/or power washed as needed so they are visibly free of soil and plant detritus. More information on sanitizing surfaces are described in the Appendix.

1.2.2. Keep plants in sanitized vehicles or on sanitized carts, trailers, etc. until delivered to their planting sites. (More information may be found in sections 1.3.3. and 1.3.4.)

1.2.3 At the job site, plants shall be handled to prevent contamination until delivered to each planting site. Nursery stock shall not be placed on the soil or other potentially contaminated surfaces until they are placed at their specific planting sites.

1.2.4 If it is necessary to offload plants at the job site, plants may be placed on clean waterproof plastic tarps or other clean, sanitized surfaces. If tarps are used for holding plants, one surface needs to be dedicated for contact with nursery stock and will be cleaned and sanitized to maintain phytosanitary conditions.

1.3. Other planting site inputs

1.3.1 Washing, soaking, or irrigation of plant material shall be conducted using clean water sources as specified in the Appendix below. Untreated surface waters should not be used for these purposes.

1.3.2. On-site or off-site collection of plant materials, including seed and cuttings for direct planting, shall be conducted in a phytosanitary manner (see guidelines for collection practices at www.calphytos.org).

1.3.3. Prior to delivery to the planting areas, mulch, compost, soil amendments, inoculants, and other organic products need to be examined and determined to be low-risk for pathogen introduction. Acceptable materials are those that are free of contamination by plant pathogens based on their composition or manufacturing conditions, or that have been exposed to an effective heat treatment to eliminate pathogens. Such materials must be handled and stored in a manner that prevents contamination. At the job site, delivered materials shall be handled to prevent contamination until delivered to each planting site in the same manner specified for nursery stock in section 1.2 above.

1.3.4. All other materials to be installed at the site shall be of new or sanitized material that has not been stored in contact with soil, untreated surface waters, or other potentially contaminated materials. This includes irrigation supplies (such as pipe, fittings, valves, drip line, emitters, etc.), erosion control fabrics, fencing, stakes, posts, and other planting site inputs.

2. Cleaning and sanitation required before entering planting area to prevent introducing contamination from other locations
Phytophthora contamination can be present in agricultural and landscaped areas, in commercial nursery stock, and in some infested native or restored habitat areas. Contamination can be spread via soil, plant material and debris, and water from infested areas. Arriving at the site with clean vehicles, equipment, tools, footwear, and clothing helps prevent unintentional contamination of the planting site from outside sources.

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2.1. V
ehicles, equipment, and tools

2.1.1. E quipment, vehicles and large tools must be free of soil and debris on tires, wheel wells, vehicle undercarriages, and other surfaces before arriving at the planting area. A high pressure washer and/or compressed air may be used to ensure that soil and debris are completely removed. Vehicles that only travel and park on paved roads do not require external cleaning.

2.1.2. The interior of equipment (cabs, etc.) should be free of mud, soil, gravel and other potentially contaminated material. Interiors should be vacuumed, washed, and/or treated with sanitizing agents as needed to eliminate pathogen propagules that could be transferred to the planting area.

2.1.3. Small tools and other small equipment (including hoses, quick couplers, hose nozzles, and irrigation wands) need to be washed to be free of soil or other contamination and sanitized (see Appendix).

2.1.4. Hoses shall be new or previously used only for clean water sources (see Appendix).

2.2. Footwear and clothing

2.2.1. Soles and uppers of footwear need to be visibly free of debris and soil before arriving at the planting area. (See the Appendix for more details.)

2.2.2. At the start of work at each new job site, worker clothing shall be free of all mud, soil or detritus. If clothing is not freshly laundered, all debris and adhered soil should be removed by brushing with a stiff brush.

2.2.3. Gloves and non-porous knee pads must be new (if disposable) or laundered/sanitized at the start of each work day, and/or clean coveralls must be worn. Non-disposable gloves should be made of or coated with material, such as nitrile, that can be sanitized.

3. Prevent potential spread of contamination within planting areas Phytophthora can also be spread within plantings areas if some portions of the site are contaminated.

However, it is not possible to identify every portion of a planting area that may contain Phytophthora.

Because Phytophthora contamination is not visible, working practices should minimize the movement of soil within the planting area to reduce the likelihood of pathogen spread.

Note that areas with higher risk of Phytophthora infestation include areas adjacent to planted landscaping, areas previously planted with Phytophthora-infected stock, areas with existing or recently removed woody vegetation, disturbed wetlands, and areas directly along watercourses. Areas with low risk of contamination typically include upland sites with only grassy vegetation or sites where surface soils have been removed.

3.1. Worker training and site access

3.1.1. Before entering the job site, field workers need to receive training that includes information on Phytophthora pathogens and how to prevent the spread of these and other soilborne organisms by following approved phytosanitary procedures. Workers should also be informed about any site-specific phytosanitary practices before work commences. 9 ITEM 13
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3.1.2. Do not bring more vehicles into the planting area than necessary and keep vehicles on surfaced or graveled roads whenever possible to minimize potential for soil movement.

3.1.3. Travel off roads or on unsurfaced roads should be avoided when soil and road surfaces are wet enough that soil will stick to vehicle tires and undercarriages.

3.1.4. To allow for adequate decontamination of equipment, tools, gloves, and shoes, avoid planting under overly wet conditions or when soil is saturated.

3.2. Minimize unnecessary movement of soil and plant material within the planting area, especially from higher to lower risk areas

3.2.1 Brush off soil from tools and gloves when moving between successive planting sites to prevent repeated collection and deposition of soil across multiple sites.

3.2.2. Avoid contaminating clothing with soil during planting operations. Brush off soil accumulations before moving from one planting site to the next. Use nonporous knee pads that are cleaned between planting sites if kneeling is necessary.

3.2.3 When possible, plant nursery stock from a given block in the same local area rather than spreading it widely. If a problem is associated with a given block of plants, it will be easier to detect and deal with it if the plants are spatially grouped.

3.2.4. Phase work to minimize movement between areas with high and low risk of contamination.

Where possible, complete work in low risk areas before moving to higher risk areas.

Alternatively, assign personnel to working in either high or low risk areas exclusively to reduce the need for decontamination.

3.2.5. Clean soil and plant debris from large equipment and sanitize hand tools, buckets, gloves, and footwear when moving from higher risk to lower risk areas or when moving between widely separated portions of the planting area.

3.2.6. All non-plant materials to be installed at the site (irrigation equipment, erosion control fabric, fencing, etc.) shall be handled to prevent movement of soil within the site, especially movement from higher risk to lower risk areas. Materials should be kept free of soil contamination by maintaining them in clean vehicles or carts, trailers, etc., or stockpiling in elevated dry areas on clean tarps until used.

4. Clean water specifications
Objective: use only uncontaminated, appropriately-treated water for irrigation.

4.1.1. Water used for irrigating plants needs to be uncontaminated. See Appendix for specifications.

Appendix
A. Procedures for sanitizing tools, surfaces, and footwear Surfaces and tools should be clean and sanitized before use. Tools and working surfaces (e.g., plant carts) should be smooth and nonporous to facilitate cleaning and sanitation. Wood handles on tools should be sealed with a waterproof coating to make them easier to sanitize. 10 ITEM 13
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Working Group for Phytophthoras in Native Habitats October 2016 Befo
re sanitizing items, remove all soil and organic material (roots, sap, etc.) from their surfaces. If necessary, use a detergent solution and brush to scrub off surface contaminants. The sanitizing agent may also be used as a cleaning solution. Screwdrivers or similar implements may be needed to clean soil out of crevices or shoe treads. Brushes and other implements used to help remove soil must be visibly clean and sanitized after use.

After surface soil and contamination are removed, treat the surface with one of the following sanitizing agents, allowing the appropriate contact time before rinsing. If surfaces are clean and dry, wet surfaces thoroughly and allow for the appropriate contact time listed. If the sanitizer has been used to help clean the surface, use fresh sanitizer to rinse off any dirty solution and then allow the required contact time.

If treated surfaces are wetted with water, the sanitizing solution will become diluted. Apply enough sanitizer to completely displace the water film and then allow the required contact time. Sanitizing agents may be applied with spray bottles to thoroughly wet the surface. Observe all appropriate safety precautions to prevent contact with eyes or skin when using these solutions. - 70-90% ethyl or isopropyl alcohol - spray to thoroughly wet the surface and allow to air dry before use
- freshly diluted bleach solution (0.525% sodium hypochlorite, Table 1) for a minimum of 1 minute (due to corrosivity, not advised for steel or other materials damaged by bleach) - quaternary ammonium disinfectant - use according to manufacturer recommendations, making sure that the label indicates that the product is suitable for your use situation and has activity against Phytophthora when used as directed. Solution should be freshly made or tested to ensure target concentration.

Table 1. Dilutions of commonly available bleach products needed to obtain approximately

0.525% sodium hypochlorite concentrations (5000 ppm available chlorine).

Percent sodium
hypochlorite in bleach
Parts bleach Parts water Diluted bleach percent sodium
hypochlorite

5.25% 1 9 0.525%

6.0% 1 10.4 0.526%

8.25% 1 14.6 0.529%

8.3% 1 14.8 0.525%
For example, adding 100 ml of 5.25% bleach to 900 ml of water will make 1000 ml of 0.525% NaOCl solution. If using 8.3% bleach, add 100 ml of bleach to 1480 ml of water to make 1580 ml of 0.525% NaOCl.

B. Clean water specifications
Surface waters, including untreated water from streams or ponds and nursery runoff, can be sources of Phytophthora contamination. Only uncontaminated water or water that has been effectively treated to remove or kill Phytophthora should be used for rinsing or irrigating plant ma terial.

5.1. Water used for irrigation shall be from treated municipal water su pplies or wells and delivered through intact pipes with backflow prevention devices. Tertiary-treated municipal recycled water is acceptable.
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5.2. I
f well water is used, wellheads shall be protected from contamination by surface water sources.

5.3 Untreated surface waters and recycled nursery runoff shall not be used, and plants shall not be held where potential contamination from such sources is possible via splash, runoff, or inundation.

5.4. Irrigation equipment must be kept free of contamination that could be transferred to irrigation water or plants. All hoses, wands, and nozzles, and hand irrigation equipment must either be new or sanitized before use. Drip irrigation and other sprinkler parts should be new or sanitized. Hose ends, wands, or nozzles that become contaminated with soil or mud during use should be cleaned and sanitized before being used further.
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Guidelines for Minimizing Phytophthora Contamination
at Midpeninsula Regional Open Space District Preserves

The goal of these guidelines is to minimize the contamination of Midpeninsula Regional Open Space District (MROSD) preserves with Phytophthora, a soil pathogen that kills plants. Once a site is contaminated, this soil pathogen can spread farther into wildland areas and can be difficult to eradicate. Prevention is the lowest cost and easiest method to manage contamination.

The best way to prevent the spread of this disease is to not move soil from one location to another by cleaning tools, equipment, and footwear.

Part of the District’s mission is to protect and restore the natural environment. Within the last few years, planted restoration sites have unintentionally exposed preserves to soil pathogens brought in by nursery plants that were later found to be contaminated. Testing of former restoration sites on District preserves is now underway to determine which sites are contaminated and the necessary remedial actions.

Who should use these guidelines?
These guidelines are intended for use by field staff and Natural Resource (NR) staff who pose the highest chance of spreading soil Phytophthora via equipment and footwear. Several methods are provided on how and when to decontaminate tools and equipment depending on the site conditions (contaminated versus clean site) and staff activities (planting, other). Guidelines for contractors, consultants, volunteers and preserve visitors are under development. Consult NR staff (Amanda Mills, [email protected] or x558, or Coty Sifuentes-Winter, [email protected] or x560) on which guidelines are best for your project.

When to use these guidelines?
Use these guidelines for any activity that contacts soil, water or plants on a known Phytophthora- contaminated site, on a formerly planted site, on a site with rare plants, or when preparing or planting a new restoration site.

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Table of Contents

1. Overview ................................ ................................ ...................3

1.1 What is Phytophthora? ................................ ................................ ... 3

1.2 General Steps: ................................ ................................ ................. 3

1.3 Proper Disinfectants ................................ ................................ ....... 4

2. Cleaning at the Field Office ................................ .........................5

2.1 Remove Soil from Equipment and Footwear ................................ .. 5

2.2 Disinfect Tools With Bleach ................................ ............................ 5

2.3 Disinfect Wheeled Equipment/ Vehicles ................................ ......... 6

3. Cleaning at Field Site ................................ ................................ .6

3.1 Cleaning at Start of Field Day ................................ .......................... 7

3.2 Cleaning at End of Field Day ................................ ........................... 8

4. FAQ ................................ ................................ ............................8

5. Sources ................................ ................................ ......................9

6. Future Methods ................................ ................................ .........9

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1. Overview
Remember to Arrive Clean and Leave Clean. The best way to prevent the spread of Phytophthora is to leave soil at its original location in the field. Equipment and footwear should be clean and sanitized before entering a site, especially for planting events where extra precautionary steps will be taken. Before leaving a site, especially at contaminated sites, it’s crucial to clean and sanitize footwear and equipment.

Definitions:

Clean - remove soil and organic debris from tools and footwear Sanitize - Use disinfecting agent such as alcohol or chlorine bleach.

Phytosanitary- control of plant pests and diseases especially in agricultural crops

1.1 What is Phytophthora?

1.1.1 Phytophthora (Fie-tof-thora) is a group of water molds that infect plants. There are many species, mostly notably P. ramorm (Sudden Oak Death), P. infestans (potato blight/ Irish potato famine) and P. tentaculata (nursery root rot).

1.1.2 Symptoms are similar to drought, making diagnosis difficult without testing.

1.1.3 Symptoms include leaf spots, branch die-back, cankers, trunk bleeding and death of whole plant.

1.1.4 Hosts include many native and nursery plants including oaks, bay laurel, madrones, sticky monkeyflower.

1.1.5 Brought to California through imported camellia and rhododendron nursery plants.

1.1.6 Mainly spreads from contaminated nursery stock, pots and soil. Can spread by foot traffic from contaminated footwear.

1.2 General Steps:

1.2.1 What - Items to be cleaned: Anything that comes into contact with soil, water or plants.

This includes tools (shovels, hand trowels, hori-horis, rakes, tree cages, plant protection tubes etc.), footwear, equipment, wheeled equipment and vehicles.

1.2.2 When - Prior to the project day, field staff will be notified what items need to be cleaned and by which method. In general, tools and equipment should be cleaned at the field office before bringing them to the field site, and soil should be removed from footwear beforehand and more thoroughly cleaned at the entrance to the field site.

1.2.3 Transportation - Cleaned equipment should be transported in a truckbed from which all soil has been washed out, or cleaned equipment can be wrapped in a clean tarp before placed in a dirty truck.

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1.3 Proper Disinfectants
All recommended disinfectants are considered pesticides. Personal protective equipment required by the State of California for anyone using disinfectants is eye protection with wrap- around and brow protection and 14 mil chemical resistant gloves. You can use smaller mil gloves if handling chemicals for 15 minutes or less.

1.3.1 The disinfectants listed in Table 1 are recommended by standard phytosanitary guidelines.

1.3.2 Other disinfecting agents or methods, such as Lysol or heat treatments, must be reviewed and approved by NR staff before use.

1.3.3 Disinfectants are most effective when surfaces are clean of soil and user follows label instructions.

Disinfecting
Agent
Active ingredient Contact
time
Product
shelf life
Proper
Disposal
Health
Risk
Personal
Protective
Equipment
Granular Chlorine
Bleach (Leslies
Chlor Brite, EZ
Chlor)
Sodium
dichloroisocyanurate
dihydrate
2 min Long if
undiluted
Neutralizer
(Vita-D-
Chlor)
High

Eyewear,
gloves; do not
inhale
Liquid Bleach
(Clorox)*
Sodium chloride 2 min 3-5
months
TBD High Eyewear,
gloves; do not
inhale
Rubbing Alcohol Ethanol or Isopropyl
Alcohol
1 min Long TBD Med Eyewear,
gloves;
flammable
Quaternary
ammonium
compounds (Quat
128 or Physan 20)
Dodecyl dimethyl
ammonium chloride
10 min Long if
undiluted
TBD Med Eyewear,
gloves; toxic
to fish
Table 1: List of approved disinfecting agents. Always follow chemical label instructions. *Liquid bleaches are generally not recommended as a disinfectant because they lose potency in storage.

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2. Cleaning at the Field Office
Clean equipment, tools and footwear at the field office before arriving to the project site. This is the easiest way to prevent soil contamination. For those occasions where equipment and footwear must be cleaned at a field site, see Cleaning at Field Site (page 7).

2.1 Remove Soil from Equipment and Footwear

2.1.1 At the field office, scrape, brush, and wash off any soil or organic material. Take care to remove soil trapped in treads or cracks.

2.1.2 Pathogens can survive inside soil clods even after soaking because disinfectants may not completely penetrate large or clayey masses. Therefore, it is important to remove large clods of soil before soaking or otherwise treating with disinfectants.

2.2 Disinfect Tools With Bleach
Several disinfecting agents are available for treating Phytophthoras (Table 1). When many tools need treatment, use granular chlorine bleach at the field office. Spraying with rubbing alcohol is more appropriate for spot treatment at remote field locations.

NEVER MIX DIFFERENT DISINFECTING AGENTS.

ALWAYS FOLLOW LABEL DIRECTIONS.

FOLLOW REQUIREMENTS FOR PERSONAL PROTECTIVE EQUIPMENT WHEN USING DISINFECTING AGENTS.

List of Equipment for Disinfecting Tools:
 Disinfectant – most frequently, we expect to be using granular chlorine bleach such as EZ Chlor or Leslie’s Chlor Brite when cleaning multiple tools at the field office.

Carefully follow the directions below when using any [?] of the bleach disinfectants.  Vita-D-Chlor (chlorine neutralizer) - This neutralizing product is only required if you used chlorine bleach as a disinfectant.
 Waterproof container - A large [minimum size?] plastic trashcan or waterproof pop-up garden trimming container in which to mix the water-based disinfectant and soak the tools.
 Hard bristled scrub brushes and paint scrapers - Grill brushes with scrapper attachment are handy tools to loosen soil from both flat surfaces and narrow cracks.  Personal Protective Equipment Close-toed shoes, apron or coveralls, protective eyewear, 14 mil chemical resistant gloves (not leather or cloth).  Clean water source - should not be cloudy or with a lot of organic material in it.

Pressure washers or nozzles are helpful to remove soil quickly and get into small cracks.

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2.2.2 Fill waterproof container with 10 gallons of water. Use label instructions to add the right amount of disinfecting agent. For granular bleach, use one teaspoon in 10 gallons to get the desired 0.525% dilution.

2.2.3 Dunk tools in solution for required soaking time (see Table 1). For granular bleach, this is 2-minutes. Just getting tools wet does not mean they will be disinfected. Think of it as chemical cooking.

2.2.4 If you used chlorine bleach as a disinfectant, it needs to be neutralized after soaking.

This ‘rinse cycle” will deactivate the bleach so it does not corrode metal and so that it is safer to dispose of the soak water. Equipment sprayed with alcohol does not require this neutralization step.

2.2.5 In addition to tools, remember to disinfect the sanitation kit, gloves, tarps, or other miscellaneous items that have come into contact with soil.

2.2.6 Let tools dry. The hose lay is great for drying tarps.

2.3 Disinfect Wheeled Equipment/ Vehicles
Anything with wheels, including wheel barrels, ATV’s, motorized carts that will be used at the field site needs to be cleaned and this is best done at the field office before the project. Vehicles that stay at the staging area do not have to be cleaned and sanitized. However, it is good phytosanitary practice to remove soil from wheels every time you leave a site.

2.3.1 Scrub down tires either by hand scrubbing or using a pressure spray wash.

2.3.2 Sanitize using disinfecting spray such as bleach (must be made weekly) or rubbing alcohol.

3. Cleaning at Field Site
Remember to Arrive Clean and Leave Clean. If equipment was cleaned and treated with a disinfectant at the field office and delivered in a clean truck, then on-site cleaning of equipment will only be required when leaving at the end of a work day. We recommend that everyone be encouraged to thoroughly clean their footwear of soil before arrival at the site, and then footwear be treated with alcohol upon arrival. Volunteers may not always be aware of this recommendation and may arrive with boots that need to be cleaned of foreign soil at the field site. Scraping all soil off equipment and footwear is required before leaving site, and sanitation of all footwear is usually recommended when leaving a site, especially for known contaminated sites. Rubbing alcohol is usually the preferred disinfectant in the field. Bleach products can be used in the field, but it is harder to mix and dispose of them properly in the field. See details below.

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3.1 Cleaning at Start of Field Day
Tools:

Portable sanitation kits include the following items in a bin: 2 tarps, boot brush with scraper, 2 spray bottles of 70% isopropyl alcohol, 2 long-handled brushes, 2 paint scrapers, and instructions. On muddy days, also bring a basin and 2 jugs of water.

Alcohol 70% Ethyl alcohol (Ethanol) or 90% Isopropyl alcohol is fine. Called rubbing alcohol at drug stores.

Spray bottle - we take the nozzles from chemical resistant spray bottles and screw them directly into the rubbing alcohol bottle. Sometimes the stem needs to be trimmed. This allows you to have a spray bottle that is properly labeled with rubbing alcohol information and precautions.

3.1.1 Any equipment or footwear not cleaned and sanitized at the field office must be cleaned and sanitized before entering the site. Off-site soil should be considered contaminated.

3.1.2 Using the items in the portable sanitation kit, set up a staging area where equipment and footwear will be cleaned and sanitized. A paved parking lot or surface near the entrance to the work site is preferred.

3.1.3 Lay out 2 tarps, one labeled ‘dirty’ and one labeled ‘clean’.

Remove any off-site soil from footwear and equipment onto the ‘dirty’ tarp. Try not to use water. If water is used, DO NOT dump potentially contaminated water onto on-site soil. Water can be dumped onto non-permeable pavement such as a road or parking lot in a low traffic area. This will UV-sterilize the dirty water (24 hr daylight cycle) as long as no clumps exist. Potentially contaminated soil in the ‘dirty’ tarp should be bagged in a trash bag and thrown away. DO NOT dispose of off-site soil at the new site.

3.1.4 Use the ‘clean’ tarp to sanitize soil-free footwear and equipment. Standing on the tarp, spray cleaned footwear and tools with 70% isopropyl alcohol, thoroughly wetting the surface. If the surface of your footwear or tools is already wet, spray extra alcohol to displace the water and allow the alcohol to soak the surface. Spray the footwear from the top down to avoid contamination.

3.1.5 Allow alcohol to evaporate (approx. 1 min) before starting work. You can stand on the tarp until your shoes are dry.

3.1.6 Footbath Alternative - we are investigating sanitizing mats where sanitizing only requires stepping on the mat. Gemplers.com, sanistride.com, and nelsonjameson.com sell both sponge mats and footbath mats for disinfecting shoes. Either chlorine bleach or non- evaporating disinfectants are used in these footbaths and the solution is changed weekly or as needed. Chemical strips are available to test if disinfectants are still effective.

Caution should be taken if footbaths and solutions are transported to avoid spills.

3.1.7 Bleach alternative in the field. We are currently recommending that the bleach alternative be used at the field office and alcohol be used in the field. Bleach may be a better alternative in the field under some circumstances (large amounts of tools that must be disinfected in field), but will require special processes for safety and to properly dispose of the chlorine treatment water. Consult with the NR Department to determine best methods under these conditions.

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3.2 Cleaning at End of Field Day
Tools:

Portable sanitation kits include the following items in a bin: 2 tarps, boot brush withscraper, 2 spray bottles of 70% isopropyl alcohol, 2 long-handled brushes, 2 paint scrapers, and instructions. On muddy days, also bring a basin & 2 jugs of water.

3.2.1 Sanitation of equipment and shoes is important for known or suspected contaminated sites. More leniency can be given for ‘clean’ sites.

3.2.2 Remove all soil and organic material from footwear and equipment. Leave soil onsite.

Use the boot scraper, paint scraper and a stiff brush to remove any soil and plant material on both the top and bottom of footwear and from tools including the digging ends and handles. Make sure to clean out crevices. On muddy days, fill the basin with water to assist in rinsing off excess soil once the majority of debris has been removed.

3.2.3 Water helps in removing dried clods of soil. This water can be dumped on-site only if the soil originates from on-site.

3.2.4 Standing on the ‘clean’ tarp, spray cleaned footwear and tools with 70% isopropyl alcohol, thoroughly wetting the surface and allowing it to dry (approx. 1 min). If the surface of your footwear or tools is already wet, spray extra alcohol to displace the water and allow the alcohol to soak the surface.

3.2.5 Before leaving the site, shake soil off the scrapers, brushes and tarp.

3.2.6 At the field office, thoroughly clean the portable sanitation kit by washing out, spraying with alcohol and drying the container and all contents before storage. The portable sanitation kit must be clean before moving to a new site.

4. FAQ
Q. What do we do with left over soil?
A. Depends on the soil. Soil from off-site should be disposed of in a trash bag and thrown away-- there’s no knowing if off-site soil is contaminated or not. On site soil can be disposed of on-site back where it came from.

Q. What do we do with dirty water?
A. Pouring on pavement or another non-porous surface should disperse the contaminated soil enough to UV (sun) sterilize the water. If using bleach, use neutralizer and the water can be considered clean and safe enough to pour out anywhere. Don’t pollute! Other disinfectants need proper disposal that isn’t safe for dumping on the ground. Contact Natural Resources Department (Amanda Mills/Coty Sifuentes-Winter) or EH&S for safe disposal procedures.

Q. How do we use the tarps?
A. Two tarps, two purposes. Dirty tarp: use as a containment area to clean off soil clogs, especially offsite soil, for later disposal. Clean tarp: provides users a clean surface to sterilize (with alcohol or other sanitation liquid) shoes and equipment not cleaned at the Field offices.

Q. When will we need to sanitize or use the kits?
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A. 1. Contaminated sites (list TBD) 2. Planting events-NR staff lead 3. When NR Staff recommend sanitation. Most of these will be NR staff lead, otherwise a leading crew member will advise on Phytosanitary BMP.

Q. Can we use hot water to sterilize?
A. Hot water can be used only if equipment bathes in 120-125° water for 30 minutes in order to be effective at killing both surface contaminants and internal infections.

Q. What about large equipment and Ranger lead projects? A. TBD. Field staff will be trained on phytosanitary measures. For field crew lead projects, a crew member should be in charge of facilitating phytosanitary compliance.

Q. Why does this take so much time?
A. It’s best to prevent rather than respond to contamination by Phytophthora. Once a natural area has been exposed to this soil disease, it can slowly spread and kill other plants. It is very difficult and expensive to kill all the pathogens in the soil of a natural area.

5. Sources
CalPhytos.org. “Guidelines to minimize Phytophthora Pathogens in Restoration Nurseries”.

Suddenoakdeath.org. http://www.suddenoakdeath.org/wp-
content/uploads/2016/04/Restoration.Nsy_.Guidelines.final_.092216.pdf

Kurowki, Chet. “Control Pathogen Spread through use of Disinfectants”. Calseed.org. http://www.calseed.org/documents/Disinfectants%2004-22-14a.pdf

Cornell University Institutional Animal Care and Use Committee “Cleaning and sanitizing equipment used in the transport of animals.”
https://ras.research.cornell.edu/care/documents/ACUPs/ACUP532.pdf

http://agriculture.mo.gov/animals/pdf/animalag_guide4.pdf

6. Future Methods
Let us know how these guidelines worked for your project! We may adjust guidelines based on feedback.
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Midpeninsula Regional Open Space District
Sudden Oak Death Precautions and Acorn Planting Protocol

1. Sudden Oak Death (SOD) Precautions
a. Prior to the start of construction work, the Construction Superintendent shall inform construction personnel that they are working in a potential SOD-infested area, the implications of the disease, and the need to prevent further disease spread. Non-English speaking personnel shall be provided the appropriate written or verbal translations. b. To the extent practical, avoid locating equipment and material near host plants and trees, especially if showing disease symptoms.
c. Route equipment away from host plants and trees, especially if showing disease symptoms.
d. Any cutting or chipping of on-site plant material shall be restricted to the project area and the debris shall remain in the project area.
e. After completing any cutting or chipping of on-site plant material, ensure that the equipment is free from host debris by first removing any visible plant material that clings to the equipment and follow with the cutting or chipping of non-host material. f. Before any equipment or vehicles leave the preserve, the contractor shall inspect the equipment and vehicles for host plant debris (leaves, twigs, and branches). Host plant debris must be removed from equipment and vehicles prior to their departure. g. If conditions at the work site are muddy due to dust suppression activities or summer rains, remove or wash off accumulations of soil, mud, and organic debris from shoes, boots, vehicles, and heavy equipment prior to exiting the preserve. If an equipment power wash station is used, its location must first be approved by the District Representative.

2. Acorn Planting Protocols
a. Prior to planting, the contractor will remove debris within a 2-3 foot diameter of the planting basin and hollow out a planting hole fist deep and wide in loose soil. Place 3 seeds on their side in the hole, cover with soil to grade and firmly pat down. Contractor shall install Tubex Shrubshelters (2.5’ height) centered on the planted seeds. Contractor shall insure that each installed Tubex Scrubshelter is in good condition and securely attached to wooden stakes with the bottom edge covered by soil. Contractor shall install a mulch layer or certified weed free stray 3 to 5-inches deep in an area of 3-foot diameter around each tree shelter. Contractor will provide and water each basin with one (1) gallon of water.
b. After the first Spring, keep only the most vigorous seedling in each basin. If space is an issue, plant trees closer together.
c. At year 5, thin trees to 2:1 ratio.
d. At year 10, thin trees to 1:1 ratio.

Midpen will gladly issue a free permit to collect acorns for use from either Coal Creek or Los Trancos Open Space Preserves to a qualified contractor.

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Guidelines to Minimize Phytophthora Pathogens in Restoration Nurseries 6

2. Clean planting materials
Objective: Start with propagative material that is free from infection or external contamination by Phytophthora species as well as other possible pathogens.

Suggested practices:

2.1. To avoid introducing Phytophthora into seed collection areas, make sure your equipment, vehicle, and footwear are clean. Clean and sanitize your footwear and tools between locations.

2.2. Where possible, collect seeds and cuttings as high above the ground as possible, preferably at least 3 ft above the soil surface.

2.3. Whenever possible, seed/fruit should not be collected directly from the ground. Seed can be knocked onto clean tarps placed on the ground or collected using seed traps. If seed is otherwise unavailable, exceptions may be considered based on the following criteria: 1). Vegetation is robustly healthy, the site is not known to be and not likely to be contaminated; 2). Seed has recently dropped on dry ground or leaf litter. Seeds that may be contaminated with soil via water splashed from the soil should be appropriately treated before storage or use (see section 9.

Sanitizing materials and treatments). Ground-collected seed will be kept separate from other collected material during seed processing and planting and should be prioritized for testing throughout propagation.

2.4. Seeds, cuttings, and other plant propagules should not be collected from the vicinity of past restoration plantings or other areas where Phytophthora infestations are known, suspected, or likely. In the unusual situations where this is not possible (e.g., for rare populations), seed or tip cuttings may be collected if collected at a distance of 1 m or more above the ground. Material propagated from such sources should be kept segregated from plant material propagated from pathogen-free areas.

2.5. Protocols for seed collection from species that are low growing (with height stature less than 1 m above the ground) should minimize the risk of potential Phytophthora contamination. In general, seed that matures after the rainy season has ended has a low risk of being contaminated if collected before fall rains begin.

2.6. Collect seeds, cuttings, or other propagules only from plants and fruit that appear healthy. Do not collect or store seeds or other propagules with apparent disease symptoms such as decay, atypical discoloration, or fungal fruiting bodies.

2.7. If possible, avoid collecting seeds or other propagules during wet or muddy conditions to minimize potential for contaminating propagules or spreading contaminated soil.

2.8. Collect propagules with clean hands/gloves and equipment (pruning shears, etc.) and place them in new bags/envelopes and new or clean containers. Sanitize gloves, hands, and tools immediately if they come in contact with soil. Sanitize cutting tools frequently.

2.9. Conduct all processing of seeds or cuttings in a clean work area with clean equipment and clean hands or gloves. Discard or sanitize any seed or propagule that is dropped on the ground or comes in contact with contaminated surfaces or materials. 23 ITEM 13
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Guidelines to Minimize Phytophthora Pathogens in Restoration Nurseries 7

2.10. Clean seed as soon as possible after collection to remove any debris before storage or stratification. Inspect stored seeds or other propagules regularly and discard materials that develop symptoms in storage.

2.11. Where compatible with seed storage and germination requirements, treat seed using heat or appropriate disinfecting chemicals to eliminate seed-borne pathogens or external contamination.

Seed treatment may be omitted for species where it is impractical or the risk of seed-borne or contaminating pathogens is negligible.

2.12. Do not bring potentially infected or contaminated plant material into clean production areas of the nursery. Properly collected seed and tip cuttings (described above) will normally be free of Phytophthora.

2.13. Plant propagules that have been in contact with the soil (divisions, tubers, rhizomes, bulbs, etc.) have an elevated risk of being infected or contaminated with Phytophthora or other soilborne pathogens. Plant stock originating from such propagules should be segregated from planting material started from cleaner sources, such as seed or cuttings and from other vegetatively propagated material from different localities. The goal is to avoid introducing pathogens, including pathogens that may be endemic to a given site, to new areas or native plant populations via plants that become infected in the nursery.

2.14. Plant propagules from the soil (divisions, tubers, rhizomes, bulbs, etc.) should be thoroughly cleaned to remove soil and inspected. Discard propagules that show evidence of decay. Surface contamination can be removed with treatments such as diluted bleach dips, but surface treatments will not eliminate internal infections. Internal infections can only be eliminated by heat treatments, but not all plant propagules will tolerate temperatures needed to kill Phytophthora infections.

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City of Palo Alto
575 Los Trancos Road Residential Project Responses to Comments on the Draft IS-MND

Final Initial Study-Mitigated Negative Declaration
Letter 1
COMMENTER: Jane F. Mark, AICP, Planning Manager, Midpeninsula Regional Open Space District
DATE: September 19, 2022
Response 1.1
The commenter requests a new figure in the IS-MND that shows the proposed building’s footprint in relation to the creek and property lines.

This figure has been added to the Final IS-MND as Figure 6 in Section 4, Biological Resources.

Response 1.2
The commenter suggests that modifying riparian vegetation may be required to create adequate defensible space for fire protection, and that such modification may require encroachment into the creek setback. The commenter states an opinion that the impacts of such vegetation removal or trimming were not adequately studied in the Draft IS-MND and that mitigation is required.

The project is currently designed to avoid all direct impacts within the creek setback zone and avoid and minimize activities within the jurisdictional riparian habitat including removal of riparian canopy. Defensible space requirements pursuant to the 2019 California Residential Code and Chapter 15 of the PAMC do not necessitate that all vegetation be cleared within 30 feet of the residence; therefore, avoidance of impacts within the setback zone and the jurisdictional riparian habitat as proposed is feasible. The IS-MND describes permitting and mitigation requirements in the case that some trimming within the jurisdictional riparian habitat is required. These impacts would be the minimum necessary to provide required clearance between the proposed structure and potentially two to three riparian trees. There is minimal brush or undergrowth present above top of bank and it does not necessarily require removal in order to provide a clear area for fire suppression operations. The vegetation that may require trimming is back from the top of bank and reduction would not increase light transmittal to the creek corridor, increase water temperatures, or decrease shaded riverine habitat for the listed fish or other aquatic species. The riparian corridor edge adjacent to the house is situated away from the top of bank and would remain wider than in other spots along the corridor and would not impede wildlife movement or existing wildlife corridors along the creek. Furthermore, CDFW is a CEQA trustee agency; the City provided an opportunity for state agencies to comment on the IS-MND through the State Clearinghouse’s Notice of Completion process; no comments from state agencies were received. No changes to the IS-MND are warranted.

Response 1.3
The commenter states an opinion that the proposed swimming pool could result in the entrapment of semiaquatic species that could travel from the creek to the pool, and that these impacts were not adequately addressed in the Draft IS-MND. The commenter suggests mitigation such as wildlife barriers and/or escape ramps.

Swimming pools can be an attractive nuisance for wildlife. Pursuant to PAMC Section 16.18.160, the pool is required to be enclosed by fencing with no more than a 2-inch gap between grade and the 25 ITEM 13
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City of Palo Alto
575 Los Trancos Road Residential Project Responses to Comments on the Draft IS-MND

Final Initial Study-Mitigated Negative Declaration
bottom of fencing, which would be a barrier to turtles, frogs and salamanders entering the pool area. The City would require adherence to PAMC Section 16.18.160 prior to issuance of building permits. Implementation of these requirements would adequately deter wildlife from entering the pool area and significant impacts would be avoided. No changes to the IS-MND are warranted.

Response 1.4
The commenter suggests that the proposed building could present a barrier to wildlife passage parallel to Los Trancos Creek, which could result in habitat fragmentation for species such as deer and mountain lion. The commenter states an opinion that these impacts were not adequately studied in the Draft IS-MND and that mitigation is required.

The project is designed to avoid impacts to the riparian corridor, which includes fencing of the creek setback zone required by Mitigation Measure BIO-3. The proposed placement of the structure is within an existing clearing on the property. The City would require adherence to PAMC Section

18.40.140(B)(3) requiring shielding of the creek from lighting. Implementation of these requirements would limit intrusion into the riparian corridor and impacts to the movement of both terrestrial and aquatic wildlife, established corridors, or nursery sites within the corridor would be less than significant. The following discussion of wildlife movement, migratory corridors, and nursery sites has been added in Section 4, Biological Resources, of the Final IS-MND, under checklist item d:

The project site is mapped within CDFW’s California Essential Habitat Con nectivity areas as
somewhat permeable to wildlife passage. However, the project site is outside of mapped Landscape Blocks for the California Bay Area Linkage Network, indicating that it is not identified as highly permeable or high-quality habitat. Within the larger landscape, the project site is surrounded by highly permeable landscape providing terrestrial species more attractive alternatives for movement around the project site. Many large terrestrial wildlife species such as the candidate threatened mountain lion (Puma concolor) and most small species such as rodents and herpetofauna avoid openings and use the cover provided by the riparian corridor.

The project is designed to avoid impacts to the riparian corridor, and Mitigation Measure BIO-3 requires fencing of the creek setback zone. The proposed placement of the structure is within an existing clearing on the property. The City would require adherence to PAMC Section

18.40.140(B)(3) requiring shielding of the creek from lighting. Implementation of these requirements would limit intrusion into the riparian corridor and impacts to the movement of both terrestrial and aquatic wildlife, established corridors, or nursery sites would be less than significant.

No additional changes to the IS-MND are warranted.

Response 1.5
The commenter requests that the City incorporate appropriate protocols as part of the Conditions of Approval for the Resource Management Permit to minimize the spread of Phytophthora-caused plant diseases, including Sudden Oak Death. The commenter provides suggestions for such measures and attaches “Guidelines to Minimize Phytophthora Contamination in Restoration Projects.”
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City of Palo Alto
575 Los Trancos Road Residential Project Responses to Comments on the Draft IS-MND

Final Initial Study-Mitigated Negative Declaration
This comment is not related to the potential impacts of the proposed project or the analysis and conclusions of the IS-MND, and therefore no changes to the IS-MND are warranted. It will be forwarded to the City’s decision makers for their consideration.